[Senate Hearing 106-968]
[From the U.S. Government Publishing Office]
S. Hrg. 106-968
COMPARATIVE RISK ASSESSMENT:
SCIENCE ADVISORY BOARD'S
RESIDUAL RISK REPORT
=======================================================================
HEARING AND INFORMATIONAL MEETING
BEFORE THE
COMMITTEE ON
ENVIRONMENT AND PUBLIC WORKS
UNITED STATES SENATE
ONE HUNDRED SIXTH CONGRESS
SECOND SESSION
__________
OCTOBER 3, 2000
__________
ON
HOW THE U.S. ENVIRONMENTAL PROTECTION AGENCY WILL MAKE USE COMPARATIVE
RISK ASSESSMENT STRATEGIES AND METHODS TO PROTECT THE HEALTH AND SAFETY
OF AMERICANS
Printed for the use of the Committee on Environment and Public Works
U. S. GOVERNMENT PRINTING OFFICE
71-529 WASHINGTON : 2002
___________________________________________________________________________
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COMMITTEE ON ENVIRONMENT AND PUBLIC WORKS
ONE HUNDRED SIXTH CONGRESS
second session
BOB SMITH, New Hampshire, Chairman
JOHN W. WARNER, Virginia MAX BAUCUS, Montana
JAMES M. INHOFE, Oklahoma DANIEL PATRICK MOYNIHAN, New York
CRAIG THOMAS, Wyoming FRANK R. LAUTENBERG, New Jersey
CHRISTOPHER S. BOND, Missouri HARRY REID, Nevada
GEORGE V. VOINOVICH, Ohio BOB GRAHAM, Florida
MICHAEL D. CRAPO, Idaho JOSEPH I. LIEBERMAN, Connecticut
ROBERT F. BENNETT, Utah BARBARA BOXER, California
KAY BAILEY HUTCHISON, Texas RON WYDEN, Oregon
LINCOLN CHAFEE, Rhode Island
Dave Conover, Staff Director
J. Thomas Sliter, Minority Staff Director
(ii)
C O N T E N T S
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Page
OCTOBER 3, 2000
OPENING STATEMENTS
Baucus, Hon. Max, U.S. Senator from the State of Montana.........60, 51
Inhofe, Hon. James M., U.S. Senator from the State of Oklahoma... 1
Lautenberg, Hon. Frank R., U.S. Senator from the State of New
Jersey......................................................... 2, 53
Lieberman, Hon. Joseph I., U.S. Senator from the State of
Connecticut.................................................... 54
Moynihan, Hon. Daniel Patrick, U.S. Senator from the State of New
York........................................................... 7, 52
Smith, Hon. Bob, U.S. Senator from the State of New Hampshire.... 3, 50
WITNESSES
Anderson, Elizabeth L., President and CEO, Sciences
International, Inc............................................. 29
Prepared statement........................................... 110
Responses to additional questions from:
Senator Baucus........................................... 125
Senator Smith............................................ 122
Brenner, Robert, Principal Deputy Assistant Administrator for Air
and Radiation, Environmental Protection Agency................. 42
Prepared statement........................................... 146
Davies, J. Clarence, Senior Fellow, Center for Risk Management,
Resources for the Future....................................... 26
Prepared statement........................................... 107
Responses to additional questions from:
Senator Baucus........................................... 109
Senator Smith............................................ 109
Guerrero, Peter, Director, Environmental Protection Issues,
General Accounting Office...................................... 9
Prepared statement........................................... 67
Responses to additional questions from:
Senator Baucus........................................... 75
Senator Smith............................................ 73
Hartnett, Katherine, executive director, New Hampshire
Comparative Risk Project....................................... 20
Prepared statement........................................... 86
Responses to addtional questions from:
Senator Baucus........................................... 90
Senator Smith............................................ 88
Hopke, Philip, Chair, Residual Risk Subcommittee, Science
Advisory Board................................................. 40
Prepared statement........................................... 150
Responses to additional questions from:
Senator Baucus........................................... 153
Senator Smith............................................ 154
Hughes, Lee, Vice President of Corporate Environmental Control,
Bayer Corporation.............................................. 44
Prepared statement........................................... 141
Responses to additional questions from:
Senator Baucus........................................... 145
Senator Smith............................................ 144
Lippman, Morton, Professor, New York University, chair, Science
Advisory Board................................................. 33
Letters, EPA...............................................132, 135
Prepared statement........................................... 128
Responses to additional questions from:
Senator Baucus........................................... 137
Senator Smith............................................ 133
McGartland, Al, Director, National Center for Environmental
Economics, Office of Policy, Economics, and Innovations,
Environmental Protection Agency................................ 7
Prepared statement........................................... 55
Responses to additional questions from:
Senator Baucus........................................... 65
Senator Smith............................................ 59
Pompili, Michael J., Assistant Health Commissioner, Columbus
Health Department, Columbus, OH................................ 23
Prepared statement........................................... 95
Responses to additional questions from:
Senator Baucus........................................... 101
Senator Smith............................................ 99
Stadler, Felice, National Policy Coordinator, Clean the Rain
Campaign, National Wildlife Federation......................... 38
Prepared statement........................................... 155
Responses to additional questions from Senator Smith......... 156
ADDITIONAL MATERIAL
Articles:
Achieving Harmony Among Environment, Economy and Energy...... 85
Air Pollution Panel Backs EPA and Six Cities Study........... 93
Scientists Question SAB's Criticism of EPA's Residual Risk
Program.................................................... 140
Letters:
Environmental Protection Agency............................132, 135
New Hampshire Comparative Risk Project....................... 86
Science Advisory Board....................................... 162
Reports:
New Hampshire Comparative Risk Project....................... 78
Columbus Community Environmental Management Plan............. 97
SAB Advisory of Residual Risk of Secondary Lead Smelters..... 164
Statements:
Biddinger, Dr. Gregory, Exxon-Mobil Company.................. 183
Brown, Dr. Stephen L., Risks of Radiation Chemical Compounds. 186
Cory-Slechta, Dr. Deborah, Department of Environmental
Medicine, University of Rochester.......................... 190
Gentile, Thomas J., New York State Department of
Environmental Conservation................................. 191
Hattis, Dr. Dale, Clark University, Worcester, MA............ 197
McFarland, Michael J., Engineering Department, Utah State
University................................................. 201
Middleton, Paulette, Center for Environmental Sciences and
Policy..................................................... 204
Parris, George E., Ph.D., director, Environmental &
Regulatory Affairs, American Wood Preservers Institute..... 158
Taylor, George E., George Mason University................... 206
Zimmerman, Dr. Rae, Robert Wagner Graduate of Public Service,
New York University........................................ 209
COMPARATIVE RISK ASSESSMENT: SCIENCE ADVISORY BOARD'S RESIDUAL RISK
REPORT
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TUESDAY, OCTOBER 3, 2000
U.S. Senate,
Committee on Environment and Public Works,
Washington, DC.
The committee met, pursuant to notice, at 9:31 a.m., in
room 406, Senate Dirksen Building, Hon. Robert C. Smith
(chairman of the committee) presiding.
Present: Senators Smith, Inhofe, Moynihan, Lautenberg, and
Baucus.
OPENING STATEMENT OF HON. JAMES M. INHOFE,
U.S. SENATOR FROM THE STATE OF OKLAHOMA
Senator Inhofe [assuming the chair]. The committee will
come to order.
I thought we would start while waiting for the chairman to
get here.
Before doing any opening statements, let me pay a special
tribute to my good friend Patrick Moynihan. Not many people are
aware of the fact that he is a Tulsa boy, from Tulsa, OK. In
fact, one of his roommates in school--what was John's last
name? John Barry, that is right, John Barry was a very liberal
Democrat and he is my next-door neighbor.
Some people accuse me of being a very conservative
Republican. Finally, he came to me one day. We used to have
these conversations about you. That was the only thing we
agreed on, nice things about Patrick Moynihan. He finally came
to me one day and he said, ``You know, this neighborhood isn't
big enough for both of us.''
And he left. So, that was the end of your friend there.
You know, in Tulsa we have a very well known morning show
that is heard far beyond the confines of Oklahoma. It is called
``The Early in the Morning Show.'' He just absolutely worships
Daniel Patrick Moynihan. In fact, he was after me since the 8
years I was in the House and the 6 years in the Senate to line
up an interview. That did finally happen.
So, even though he was quite young when he left Tulsa, he
is one that we claim as our own, Daniel Patrick Moynihan.
Our chairman has just arrived. Chairman Smith, I started
without you. Let me finalize this comment because I know that
your family was with the Tulsa Tribune at one time. I ran
into--and I hadn't seen him for 10 years--Jake Jones on the
airplane yesterday. You know, the paper is no longer there any
more. I hadn't seen him in probably 12 years and I ran into him
on the plane.
So, anyway, we are very proud of Pat Moynihan to be a
native Tulsan. He is part of our area.
Senator Moynihan. You are very generous, sir. I am proud to
have such an origin.
Senator Inhofe. Well, if you hadn't been so young, you
wouldn't have been willing to leave, I am sure.
Senator Lautenberg. Mr. Chairman.
Senator Smith [assuming the chair]. Senator Lautenberg.
OPENING STATEMENT OF HON. FRANK R. LAUTENBERG,
U.S. SENATOR FROM THE STATE OF NEW JERSEY
Senator Lautenberg. May I ask, we have a Transportation
Conference about ready to start, miracle of miracles, and I did
want to have just a couple of minutes to talk about my friend
to my right, and that is often the position. May I have that
time now?
Senator Smith. Go ahead.
Senator Lautenberg. I would ask the involvement of the
witnesses. Pat Moynihan and I are probably on our--I want to
say ``last legs,'' but on our last committee, the Environment
and Public Works Committee. I think it is fair to say that in
the year that you joined this committee, Senator Moynihan, it
was called the Committee on Public Works. Then the word,
``environment'' was added. Is my briefing paper correct?
Senator Moynihan. I believe, sir, Senator Muskie had just
added ``environment.''
Senator Lautenberg. Well, I am sure your influence helped.
I am awfully glad you did because Senator Moynihan and I are
from either sister or brother States, however you phrase it.
The fact of the matter is that we are inextricably linked
because of the necessity to function together in our region.
For me, Senator Moynihan, it has been a distinct honor and
pleasure. We have worked together on some fairly important
issues that under the jurisdiction of this committee: clean
water, clean air, trying to make sure that the harbor keeps
functioning so that we have the depth to accommodate the ships
that are now plying the harbor waters, but also those in the
future.
We dare not stand by and let changing conditions impair our
economy, whether it is heavier trucks on the highways, which we
had to accommodate, or changes in our aviation system, we
stepped up to the plate and did it.
In the case of dredging in the harbor, it is a phenomenon
resulting from new technology and larger vessels. So, I
remember that it was in 1985 that we stood at the top of the
World Trade Center calling for tougher standards to control air
toxics. Ultimately, we were able to beat back the
Administration's efforts to weaken the requirements on
midwestern power plants that spewed air pollution all over our
two States.
Senator Moynihan's conscience, intellect, and integrity
have made him a fearsome adversary. By the same token, if you
need a friend and a soldier in the ranks or a partner in duty,
Pat Moynihan was the person you could call on.
Pat Moynihan also has the distinction of recognizing the
tremendous toll of air pollution in terms of acid rain and its
effect in the Adirondacks and other mountainous and lake areas
in his beautiful State.
So, I say that the Senate will be a poorer place as a
result of the retirement of departure of Pay Moynihan from the
Senate. One of the things that we hope is that he will continue
to stay involved in public policy.
There is such a wealth of experience and information there.
As I said earlier, also the intellect to support the use of
that knowledge and that experience, whether it has to do with
our international relationships or whether it has to do with
making sure that we pay attention to the needs of our railroads
and our transportation system or making certain that the water
that our people drink is safe.
So, I say this, Senator Moynihan, that is not bottled
water. I want everybody to know that.
Thank you, Mr. Chairman, for this opportunity to say these
few words.
Senator Moynihan. Mr. Chairman, I would like to thank my
dear colleagues from Oklahoma and from New Jersey. We have been
together a long while and we will continue. Thank you.
OPENING STATEMENT OF HON. BOB SMITH,
U.S. SENATOR FROM THE STATE OF NEW HAMPSHIRE
Senator Smith. Well, I know we are embarrassing you,
Senator Moynihan, but in reflecting, you have the same
unfortunate experience that I did in that you assumed the
chairmanship upon the death of a colleague in the middle of the
session. Senator Burdick passed away and you assumed the
chairmanship, as I did when Senator Chafee passed away. So, we
have, unfortunately, something in common there.
But I also wanted to remind you of the time that you, not
long after having assumed that chair and when I was a fairly
young, in terms of tenure here, Member of the Senate.
You came to my office after having assumed that
chairmanship and insisted on coming to my office rather than me
coming to yours and gave me a great opportunity to have
significant input into the transportation bill which you were
then working on. I have never forgotten that.
You hear oftentimes the expression of people who are both a
gentleman and a scholar, and you are both. I mean that. It is
very, I think, well, it is certainly timely but perhaps no
accident that you are here. This is your last hearing. Yet, it
is on risk assessment and you have had so much to do with it. I
have a long litany of things, which I am not going to read, but
I will put in the record your conversations in that area.
So, it has been a real pleasure to serve with you.
Senator Moynihan. Thank you, Mr. Chairman.
Senator Smith. I appreciate your friendship.
Senator Moynihan. It will be a pleasure to hear our
witnesses if you want to get on with it.
Senator Smith. Senator Lautenberg, this is also your last
hearing, I believe. It seems like we have had four or five
``last hearings'' for you.
Senator Lautenberg. Keep them going.
Senator Smith. You really enjoy this. But, I did make some
comments the last time on the record for you.
Senator Lautenberg. You did. I don't feel deprived, Mr.
Chairman. I truly appreciated it. I would appreciate one more
courtesy, and that is, if I could submit my statement on this
hearing into the record.
Senator Smith. All members' statements will be submitted
for the record.
Senator Baucus has just come in. Why don't we just have
the first panel come up while Senator Baucus makes a few
remarks?
Senator Baucus. Thank you, Mr. Chairman. This is quite a
day. It is bittersweet. It is a time when we are happy for the
Senator from New York but we will also sorely miss him.
Senator Moynihan has been a friend to all of us on the
committee. He has certainly been a mentor to me. He teaches the
best way, which is by example, not by telling people what to
do, but by example, by coaxing out our better angels.
Senator Moynihan is optimistic. He is positive. He appeals
to the more noble side of human nature, and again, by example.
He always encourages us to think a little harder, think a
little more deeply, think about something that is off the
beaten path, and listen a little more carefully. He is always
stressing honor and always stressing civility.
He elevates our debates in many ways, with his sharp
intellect, and certainly with his very, very deep, broad grasp
of public policy, often bringing up historical references that
help clarify matters a little, put things in perspective, focus
our minds a bit more.
Every once in a while, I try to match him, and I try to
impress him coming up with an historical reference of my own. I
must say that each time he corrects me.
I will never forget the moment I told him that it was that
great statesman, Disraeli, who said that, ``In politics a week
is a long time.''
Right away he corrected me and said, ``No. I think that was
Baldwin.''
And he was right.
A few months ago, though, we passed a law naming Foley
Square Courthouse in New York after Senator Moynihan. I worked
very hard on this speech. I wanted to use the occasion to
describe Senator Moynihan's extraordinary contribution to our
Nation's public architecture. It is well known, both in the
District of Columbia and New York. I closed by quoting the
inscription in St. Paul's Cathedral memorializing Sir
Christopher Wren. The quote is, ``If you would see his
memorial, look around.''
Well, I said the same could be said about Pat Moynihan.
That is, if you look down Pennsylvania Avenue or up to the new
courthouse you could see his memorial by just looking around.
Well, the Senator seemed pretty pleased with my remarks and
he thanked me profusely. He also corrected me in his ever-so-
courteous, gentlemanly, civil way. He said, ``Max, I must note
that your translation was correct. But the inscription is
actually in Italian.''
I was crestfallen. I had tried to come up with something
that was accurate that would just be the perfect statement that
would capsulize the Senator. Well, I must say I have done a
little further research. It is true the inscription marks Sir
Christopher Wren's resting place. It is also true it is under
the east end of the church. But my very, very good friend, it
is hard for me to say this, was slightly off. It is not in
Italian, but it is in Latin, ``Lector, situation monumentum
requiris, circumspice.''
Senator Moynihan. Well, I got that right.
Senator Baucus. You always have the last word, and always
accurately and always teaching. I will say no more, except that
he is one of the most wonderful human beings that I have had
the pleasure to know and certainly one of the best Senators
that we have all had the pleasure to work with. Again, just a
wonderful, wonderful person.
Senator Moynihan. I am deeply honored, my dear friend.
Senator Smith. Thank you, Senator Baucus.
Let me welcome everyone to the hearing this morning on the
use of comparative risk assessment in setting our environmental
priorities. We will hear testimony on the Science Advisory
Board report on EPA's case study analysis of residual risk.
I think the materials that we received today for the
hearing show that there is a real interest in using the
comparative risk assessment to prioritize our resources.
I am particularly pleased that Ms. Kate Hartnett, the
executive director of the New Hampshire Comparative Risk
Project is here today to talk about New Hampshire's experience
with comparative risk. Her testimony demonstrates the continued
passion and the innovative spirit that the States and the local
governments are bringing to environmental protection that
sometimes we forget.
This is the third in a series of general oversight hearing
conducted by the full committee. Our first hearing looked at
the EPA's proposed budget for fiscal 2001. Our second focused
on State successes and the need for a new partnership between
the States and the Federal Government.
Today's hearing takes us to the next level, beginning the
process of identifying the tools that we will improve our
environmental programs with. A comparative risk assessment is
one of those tools. We all recognize that there are not enough
resources available to address every environmental threat. I
think that is the problem, that we forget sometimes that there
are not enough resources to address every single environmental
threat that we have. So, we have to prioritize.
The Federal Government, States, local communities, private
sector and even the environmental organizations all have to
target limited resources on the environmental problems that
present the greatest threat to human health and the
environment.
Our focus therefore is and should be on getting the most
out of our dollars. Comparative risk is the tool that enables
us to prioritize the risks to human health and the environment
and target those limited resources on the greatest risk.
It provides the structure for decisionmakers to do three
things. No. 1, identify the environmental hazards. No. 2,
determine whether there are risks posed to human beings or the
environment. No. 3, characterize and right those risks. Risk
managers can then use that analysis to achieve greater
benefits.
Finally, we will hear how EPA is using comparative risks to
focus on the right problems and strategies and to what extent
this approach has led to the development of a results-oriented
strategic plan, an overview.
We will hear how many States and local governments are
already using comparative risk assessment, a public and open
process that allows cooperation instead of confrontation,
encourages dialog instead of mandates, and States are setting
priorities. They are developing partnerships. They are
achieving real results by using this comparative risk as a
management tool.
They are using good science to maximize environmental
benefits with limited resources. I believe we should encourage
and promote that. Hopefully, we will hear that this morning
from the witnesses.
Let me welcome this morning Mr. Al McGartland, Director of
the National Center for Environmental Economics, Office of
Policy, Economics, and Innovations of the Environmental
Protection Agency. Welcome.
I would also like to welcome Mr. Peter Guerrero, Director
of the Environmental Protective Services at GAO. We are glad to
have you here.
Senator Baucus, did you have an opening comment?
OPENING STATEMENT OF HON. MAX BAUCUS,
U.S. SENATOR FROM THE STATE OF MONTANA
Senator Baucus. Mr. Chairman, first of all, I really
appreciate your holding this hearing. It is a very important
subject that we are going to have to delve into more deeply as
time proceeds.
The second, longer statement I would like to include in the
record.
I would like to begin that it is always important for this
committee to look at new tools for improving the way we protect
public health and the environment. I believe that is a given.
I believe that risk-based tools such as comparative risk
assessment can help us. There is not much doubt about that. But
when we proceed thoughtfully examining comparative risk and
residual risk, I think we should also clearly understand that
these are tools, I mean these are mechanisms. They are ways to
help us achieve our goals.
It is important for us to realize what these tools can do,
but also what they cannot do. As with any tool, any mechanism,
there is always a limitation. In the case of risk assessment,
one inherent limit is that the science on which it is based
isn't, and it really never can be complete. That is simply the
nature of science. Science is an analytic logical pursuit which
is just that.
We also have to factor uncertainty into our decisions. We
also must recognize in addition to science there are other very
important values, values such as fairness, values such as
equity which are essential components of any environmental
decision.
The bottom line is that tools such as risk assessment can
certainly help us form our decisions, but they can't by
themselves tell us what that decision is and what decision to
make.
Also, Mr. Chairman, I would like to briefly comment on the
subject addressed by our last panel this morning, namely the
status of the residual risk program. I know that some have
questioned has the ability or the resources to remove residual
risk from the environment, suggesting that EPA doesn't have
enough data or does not have the right data or the right
models.
I must say, some of those criticisms are frankly correct
only in part, but those feelings may have more to do with
inadequate funding and organization than they do with the lack
of good science. The 1990 amendments to the Clean Air Act, in
those amendments, the conferees carefully considered the issue
of residual risk. It was not just thrown in at the last minute.
We also knew there would be uncertainties associated with
estimating the risk. That is why we required a report to
Congress first with any necessary regulation to follow. It is
also why EPA must consider many factors including costs, energy
and safety before deciding to issue new regulations.
So, in conclusion, I want to thank our chairman for holding
this hearing. It is an extremely important subject. I look
forward to the testimony.
Senator Moynihan. Mr. Chairman, may I make a very brief
remark to continue on what Senator Baucus has said?
Senator Smith. Surely.
OPENING STATEMENT OF HON. DANIEL PATRICK MOYNIHAN,
U.S. SENATOR FROM THE STATE OF NEW YORK
Senator Moynihan. We are beginning to see the maturing of
the whole subject of environmentalism. When I first came on
this committee nearly a quarter of century ago, with great
respect, our hearings consisted of earnest young people telling
us the sky was falling. Well, how did they know? Well,
everybody knew. Well, everybody didn't know.
We have almost a quarter of century of gradually building
into our legislation, as Senator Baucus has said, some
specifications about learning to measure. Never do anything
serious about a subject until you learn to measure it. We are
now doing it. This is advanced mathematics in many cases, but
it is a mathematics we know. Linking the mathematics with
actual data is the work we are involved with. I think it is a
very cheering note with which to take leave of you all.
Senator Smith. Let me just say to the witnesses, your
complete statements will be made part of the record. Please try
to summarize them in 5 minutes.
We are going to be interrupted around 10 o'clock by a vote.
So, hopefully, we can get through your statements and perhaps a
question or two before we get to that point. We will probably
have to recess for a few minutes during that vote.
Mr. McGartland.
STATEMENT OF AL McGARTLAND, DIRECTOR, NATIONAL CENTER FOR
ENVIRONMENTAL ECONOMICS, OFFICE OF POLICY, ECONOMICS, AND
INNOVATIONS, ENVIRONMENTAL PROTECTION AGENCY
Mr. McGartland. Mr. Chairman and members of the committee,
thank you for inviting EPA to provide our views on the use of
comparative risk assessment. I am honored to be here today.
In my role as the Director of the National Center for
Environmental Economics, I provide technical expertise and core
research to users of comparative risk analysis. As its name
implies, comparative risk analysis involves the simultaneous
consideration of a wide range of environmental risks so that
the seriousness of risk can be characterized relative to one
another.
EPA has invested in the development of comparative risk.
Our bottom line is that comparative risk assessment is an
important tool to help inform our budget and priority setting
processes. While it will continue to improve, there are
difficulties and limitations that must be well understood. It
is not a white line or a mechanistic solution to our difficult
priority decisions.
EPA generally applies comparative risk at the national
level. State and local governments undertake these studies at a
smaller geographic scale and we are pleased to see that
representatives from cities and States have been invited to
present their perspectives to this committee.
Recently, private companies and industrial sectors are
using comparative risk assessment as they incorporate
environmental management systems into normal operating
procedures. By ranking the environmental problems associated
with their operations, businesses can target their protective
efforts to the worst risk to workers and surrounding
communities and they can achieve the best results at least
costs.
EPA has a growing investment in these studies. Our first
comparative risk analysis released in 1987 ranked 31 different
environmental problems in four different classes: cancer risk,
non-cancer human health risks, ecological risks, and welfare
effects.
Later, we asked our Science Advisory Board to review these
findings and recommend improved methods for assessing and
comparing these risks. Even more recently, EPA has published a
detailed national study of the benefits and costs of air
pollution. The study broke new ground by making extensive use
of original exposure modeling and risk assessment.
Finally, our Science Advisory Board recently finished a
report on integrated decisionmaking incorporating comparative
risk assessments. We continue to work on additional studies to
help us in our priority setting and decisionmaking process. In
fact, EPA now routinely incorporates comparative risk
assessments in our internal decisions and in our partnerships
with State, local and tribal governments.
For example, the performance targets identified in EPA's
strategic plan reflect the relative priority the Agency will
place on different environmental problems and programs.
Comparative risk considerations have been explicitly factored
into various internal agency-wide budget exercises.
Furthermore, risk information, when available and relevant,
is implicitly included in most discretionary decisions made by
agency program managers, both in setting priorities within
major programs and allocating resources across programs.
For example, we are using comparative risk assessments to
help develop our schedule for controlling source categories of
toxic air pollutants under Section 112(e) of the Clean Air Act.
Our EPA State-tribal partnership activities also use
comparative risk analysis. Between 1990 and 1999 EPA provided
financial aid, about $1 million per year, to States,
localities, tribes and watershed organizations to support
comparative risk projects of their choosing.
In most cases these projects resulted in a much clearer
understanding of local environmental challenges and sometimes
they inspired new environmental initiatives.
In 1995, EPA and the States jointly entered into the new
National Environmental Performance Partnership System, or
NEPPS. Under NEPPS, EPA and the States jointly set priorities
for actions and comparative risk assessment is one of the
management tools used by States to determine which programs
they want to target for improvement.
NEPPS also gives the States more flexibility in
administering EPA grant funds. States can now consolidate a
variety of individual grants into one. In short, greater
flexibility and comparative risk have come together to
strengthen traditional partnerships.
Despite the data and methodological improvements that have
been made over the last decade, comparative risk assessment
remains an imperfect tool. EPA does not view comparative risk
assessment as a white line or a mechanistic way of ordering the
Agency's priorities for strategy, budgets or actions.
A number of other factors also have to be considered. For
example, many Federal laws set timetables and deadlines for EPA
to take specified actions or accomplish specified goals. EPA
has an obligation to comply with those legal requirements
regardless of the extent to which they reduce risk relative to
other actions we might take.
Another difficult problem arises in an attempt to include
human health and ecosystem risks in the same ranking. How do
you prioritize risks associated with pollutant exposures that
may cause cancer in humans as compared to degraded water
quality, say, in the Chesapeake Bay that may deplete oyster
beds?
The Science Advisory Board recognized this problem when
they completed their reducing risk report and they did not
attempt to include human health and ecological risk in the same
ranking.
This is not a complete list of all the factors that enter
into EPA's priority setting process. Other hard-to-quantify
considerations like inter-generational equity and environmental
justice also have to be weighed.
For our purposes here today, I simply want to emphasize the
comparative risk assessments for providing EPA with a useful
mechanism for helping us think about environmental priorities,
but by themselves, they cannot provide complete answers.
Thank you very much.
Senator Smith. Thank you, Mr. McGartland.
Mr. Guerrero.
STATEMENT OF PETER GUERRERO, DIRECTOR, ENVIRONMENTAL PROTECTION
ISSUES, GENERAL ACCOUNTING OFFICE
Mr. Guerrero. Mr. Chairman, we appreciate the opportunity
to testify on the challenges that EPA faces in using
comparative risk assessment to set priorities. My remarks are
based on GAO's long-standing work in this area from our 1988
Comprehensive General Management Review of the Agency to our
more recent efforts by EPA to develop the outcome-oriented
measures under GPRA.
In summary, I would like to make two points. First, while
EPA's priorities should reflect an understanding of the
relative risks of environmental and public health concerns,
good data often do not exist to fully characterize these risks.
In the absence of reliable data, public perceptions of risk
can influence how EPA determines its priorities and allocates
resources. EPA's ability to assess risks and establish risk-
based priorities has been hampered by data quality problems,
including critical data gaps, data bases that are not
compatible with one another and persistent concerns about the
accuracy of the Agency's data.
EPA has taken major steps during the past few years to
improve its data and to better inform the scientific community
and public of environmental public health risks, but more needs
to be done.
Second, measuring program results or outcomes is critical
to determine EPA's effectiveness and the extent to which it is
successfully addressing the most serious environmental
problems.
Nevertheless, the Agency has historically relied on
activity-based output measures, such as the number of
inspections performed, because of the inherent difficulties in
establishing sound linkages among program activities and
environmental improvements in public health.
Spurred by the requirements of the Results Act, EPA has
made progress in recent years in measuring the outcomes of its
efforts, but more progress is needed here as well.
A short history is helpful for understanding the challenges
that EPA faces in setting risk-based priorities and measuring
performance. Since EPA's establishment in 1970, the Federal
Government has developed a complex system of laws and
regulations to address environmental problems.
Over the years as environmental threats were identified,
the Congress responded by enacting new laws to address each new
problem. However, these laws were not integrated to provide EPA
with an overall system for setting priorities to ensure that
the most important problems were addressed first.
Compelled by budgetary constraints and a growing list of
problems, EPA began in the late 1980's to consider whether its
resources were being spent on the problems that posed the
greatest risk. The Agency concluded the Nation was devoting
more resources to the problems that had captured public
attention than to problems that were lesser known, but
potentially more serious.
Subsequently, EPA began incorporating the concept of
relative risk and environmental risk in its decisionmaking.
However, establishing risk-based priorities, as I mentioned,
requires good data and EPA's ability to make these assessments
is limited by three factors.
The first factor is the extensive gaps exist in EPA's
knowledge about environmental and health risks. Let me give
three examples. EPA's integrated risk information system, which
is a data base of potential health effects from chronic
exposure to various substances, lacks basic toxicity data for
about two-thirds of the known hazardous air pollutants.
The second example: EPA's national water quality inventory
does not accurately describe water quality conditions
nationwide. Only 19 percent of the Nation's rivers and streams
are assessed for the 1996 inventory, the latest available at
the time of our review, as were only 6 percent of ocean and
shoreline waters.
A third example: Of some 1456 toxic chemicals we recently
reviewed, actually human exposure data were being collected for
only 6 percent. For example, of the 475 chemicals that EPA
identified as in need of testing under TSCA, only 2 percent
were being measured for human exposure.
EPA has recognized that it has numerous and significant
gaps in its data and has initiated several efforts to fill
these gaps.
A second challenge facing EPA is incompatible data systems,
which makes it difficult for EPA to effectively use information
that it does have to manage risks and set priorities.
Over the years, EPA has developed and maintained stovepipe
data systems that make the sharing and integration of data
difficult. EPA now recognizes that common data definitions and
formats, known as data standards, are essential to its efforts
to integrate data from various data bases, including those of
its State partners.
In recent years, EPA has undertaken several efforts to
develop standards for some of the data items in its information
systems. According to EPA's Reinventing Environmental
Information Action Plan, six standards will be developed,
approved by EPA in partnership with the States and in use in 13
data bases by the end of fiscal year 2003.
However, EPA recognizes that current data improvement
efforts are only the first step toward its goal of full data
integration.
The third challenge confronting EPA is the data that it
does have is often not accurate. In various reviews, we and
others have shown that persistent concerns exist about the
accuracy of data in many of EPA's information systems.
While EPA acknowledges that data errors exist, the Agency
believes that in the aggregate its data are of sufficient
quality to support its programmatic and regulatory activities.
However, EPA has not conducted an agency-wide assessment of the
accuracy of its information systems.
To address such problems, EPA revised its agency-wide
quality system in 1998 to expand and clarify requirements for
how environmental data are to be collected and managed.
Although the Science Advisory Board recently commended the
Agency for its development of the system, the Board also found
the implementation has been uneven.
Moreover, the Board reported that 75 percent of the States
authorized to implement EPA environmental programs lacked
approved quality management plans.
Finally, Mr. Chairman, I would like to discuss EPA's
efforts to develop performance-oriented measures. Closely
linked to EPA's ability to manage risks and set priorities is
its ability to measure whether what it does is in fact reducing
environmental health threats.
EPA has long been aware of the need for environmental
measures; nevertheless the Agency has made little progress in
developing measures until the results act mandated their use by
requiring Federal agencies to report annually on their progress
in meeting their performance goals.
Still, of the 364 performance measures that EPA has
developed, only 19 percent are outcome measures. The rest are
activity measures such as the number of permits issued or
inspections undertaken. Developing outcome focus measures will
require better data, resources and strategies and, most
importantly, sustained management commitment.
In conclusion, GAO's work has identified numerous problems
in the quality of EPA's data and the way the Agency manages it.
These problems cut across programs and limit the Agency's
ability to both assess and compare risks and to measure
environmental results.
To its credit, EPA has initiated actions to improvement
information management activities, but while EPA has made
progress, it does not yet have a long-term strategy to ensure
the completeness, compatibility and accuracy of its data.
That concludes my remarks. I would be happy to answer any
questions you may have.
Senator Smith. Thank you, Mr. Guerrero.
I think we are going to have to make an administrative
decision here to go vote. We are about halfway through the
vote. So we are going to recess for about 10 minutes. We will
get back as quickly as possible. We apologize for the
inconvenience. Thank you.
[Recess.]
Senator Smith. The hearing will come back to order. I think
the other Senators will be back shortly.
Mr. McGartland, let me just ask you a couple of questions.
In your opinion, is EPA trying to develop a roadmap for ranking
these environmental problems as a function of risk?
Mr. McGartland. The answer to that is yes, and let me
explain. I mentioned in my remarks the 1987-released study.
When that was done, that was the first of its kind, I think
there were a lot of people in the Agency that really thought
twice about whether this be done or could it be done, even.
But, as any sort of phenomenon has sort of momentum behind
it, it has become woven into the fabric of the Agency in many
ways. So, I would be hard-pressed to find a program manager who
didn't know the results of the Science Advisory Board studies
or even the 1987 study and how they have evolved over time. So,
I think it has become almost a backdrop to how we do business
within the Agency in terms of thinking about what we should be
doing next, et cetera.
Then, I think that each program office is doing this, like
the Air Office I mentioned earlier and the comprehensive
benefit cost study that they did. I think they have even gone
beyond looking at comparative risk, but thinking about the
risks that are posed and the feasibility and costs associated
with reducing those risks, you know, sort of looking backward
and also looking prospectively in to the future.
Senator Smith. When you look at the way the program offices
are designed as well as the way the legislation, frankly, is
designed, the stovepipe that Mr. Guerrero mentioned, it is
really laid out to compete against the concept of comparative
risk assessment, isn't it?
Mr. McGartland. Well, I think comparative risk assessment
is certainly easier to do with any given media like air or
water, say, because your expertise and the models that one
would deploy, the fate and transport models and the scientific
models within a specific media share a lot of things in common,
but are different across media.
I am an analyst, and from an analyst's perspective I think
you can say a lot more with more certainty about the cost and
benefits within a specific media rather than making those leaps
across media.
I think the other thing that stopped the Agency from just
thinking about comparative risk is the other attributes of
risks, like is it an exposed subpopulation? It might be a very,
very high risk, but the general population might be at low
risk.
How do you rank maximum risk compared to total risk or
aggregate or average risk? How do you think about, as
mentioned, ecological risk versus human health risks? All those
issues, including feasibility, I think, curtail or limit the
ability of the Agency to think of just comparative risk in
terms of putting its steps forward.
Senator Smith. Well, I think your critics would say that
there is not enough of the interaction, that the stovepipe
concept does in fact exist. You know, in the Clean Air Act, we
do it here. That is the way the legislation is designed, as
well.
If you try to say that more focus should be put on one of
the stovepipes over another, then you become anti whatever the
one is you are criticizing rather than pro-comparative risk
analysis. I mean, if you go to any community, pick any
community in America and let's just say they have a Superfund
problem, they have a Clean Air problem. Maybe they have a CSO
problem, why can't they make the determination what is the most
immediate threat to them, to their environment, to their health
and safety?
That is not happening; is it? I mean it can't be the way we
have it now. There might be some risk assessment and
prioritization done within the pipe, but not between the pipes.
Mr. McGartland. I am not as familiar at the State level
since mainly my expertise and analysis is generated more toward
national studies. But I do think, both from an institutional
point of view, but also from an analytic point of view, it is
difficult.
I don't know how to compare sort of Superfund risks to a
given subpopulation compared to sort of particulate matter.
Senator Smith. But I think that really is the issue. There
is no Federal entity, at least that is what some of the
witnesses have said in their written testimony that are going
to follow you, or at least one witness said it anyway, there is
no Federal entity that promotes and directly assists any State
and local government with risk-based decisionmaking.
I mean if it is a priority with you to use this comparative
risk assessment, why not work with the States and local
communities to do it? Is there any entity within your
department to do that? There is none that I know of, but the
question is why not?
Mr. McGartland. Well, I think I would have to get back to
that, Senator. My shop is sort of supporting the program
offices. I would certainly welcome the chance to get back to
you and the committee on an explanation for that.
Senator Smith. Yes, I think it would be good to provide at
least your view on it for the record as to how we might go
about assisting. I might ask some of the other witnesses what
their thoughts are on it as well.
Mr. McGartland. We did, as I mentioned in my remarks--in
the 1990's we had a program that worked with State and local
governments to think about comparative risks and to actually
take them on.
Senator Smith. Let me ask you, Mr. Guerrero, do you have
any specific recommendations that you would like to make to
either of us in the Congress or to the Agency in this regard in
terms of how we might do better at comparative risk assessment?
Mr. Guerrero. Mr. Chairman, I think the heart of the
Agency's ability to do this type of risk comparison and risk
management depends on the quality of the data. I would want to
emphasize the key points that we have made that too often data
are incomplete. When they are available, the accuracy of the
data is sometimes suspect.
The systems that EPA has to manage with are incompatible
with one another. So, there is need for data standardization to
allow for the integration of information to allow for this type
of risk management to occur.
We have made specific recommendations to the Agency to
correct these three problems. Fundamentally, we feel the Agency
needs a strategic plan that will set forth a clear
understanding of where those data gaps are, which ones need to
be addressed first, that would establish clear milestones for
taking steps to fill in the gaps and that would identify the
resources that would be required to deal with that.
I would say that it is in the resource area that the
Congress can be of most assistance to the Agency. Data
collection and data management have always, when push comes to
shove, gotten the short end of things.
It is so critical and so fundamental to the Agency's
ability to set priorities and to manage risk that it is
important that the Congress work very closely with the Agency
in making sure it has the resources it needs to do that job.
Senator Smith. What would you suggest that EPA do to
develop additional result-oriented assessment?
Mr. Guerrero. Again, I think the key there is data. This
year, as we do every year, we looked at their compliance with
the Results Act. We observed, and program managers told us,
limited availability of data on environmental conditions and on
the health effects of pollutants was a major challenge to
developing outcome goals and measures.
We also observed that a number of EPA offices were doing a
better job than others in helping to develop these outcome
measures and fill in those kinds of data gaps.
The Office of Enforcement, for example, had done a fairly
good job. But this was an area that required continued
attention by the Agency. So, I would say that central to better
performance management is again having the right data to assess
conditions and to assess results and make corrections in
programs to ensure that they achieve their results.
Senator Smith. Just a final question for you, Mr.
McGartland. Under Executive Order 12866, EPA prepared detailed
cost-benefit analysis for all economically significant
regulations. Under that order EPA was supposed to review
periodically existing regs that are economically significant to
determine if they can be made more effective or less
burdensome.
How effective has EPA been in carrying out those
responsibilities?
Mr. McGartland. I am familiar with only some of those
efforts, not every one, since I am in the policy office and not
in individual programs. But I know from the standpoint of the
Air program, we did a benefit and cost study of the Clean Air
Act. We did both a retrospective look from 1970 to 1990, and a
prospective look from 1990 into the 2010 timeframe.
In the process of carrying out those studies, we looked at
individual provisions of the laws. In that report we highlight
where the regulations are that are the biggest net benefit-
producing regs and areas of regulatory programs and which are
not.
So, in that sense I think we can take away a pretty
complete picture in the air quality arena. We are right now
working with the Water Office on a similar study, which should
highlight programmatic areas with benefits-cost estimates with
them.
Senator Smith. Well, what kind of followup are you doing on
what you find?
Mr. McGartland. Well, two things. One is that we are taking
some of the results from the Clean Air Act study, for example,
and we are incorporating that in our programmatic priorities.
For example, in the air toxic side, EPA proposed a budget shift
to move further away from technology-based standards to more
risk-based multimedia standards on hazardous pollutants.
So, I think the study is fairly new and the followup is yet
to come. The news on the air side was, in general, the net
benefits were quite large.
Senator Smith. I have been on this community for 10 years
and I have seen some movement in the right direction in risk
assessment. But I will tell you the way I view it and if either
of you disagree, then defend yourselves.
In my view, I think the majority of any risk assessment is
done within each of these stovepipes. I don't see a lot of risk
assessment being conducted between the pipes. That, I think, is
the root cause of the problem as far as local communities are
concerned.
You are asking local communities to defend themselves
against EPA perhaps on a Superfund site that, yes, it looks
ugly, yes we would like to clean it up, but no, it is not
causing anybody any health problems, it is really not causing
any significant environmental problems immediately to the
community or members of the community.
But, you know, we have other problems. We are not in
attainment with our clean air or perhaps we have a river that
is being polluted or whatever and we can't get the resources
that we need focused on that because we have to worry about a
Superfund site that we probably don't have the technology to
clean up and you are telling us we are in non-compliance.
Unless you are willing at the Federal level to begin to
look at this and work with the States to move away from this
stovepipe, we are never going to get there. I think we have to
get out of the box.
That is my view. I think there are some within the Agency
who are talking that way, but I think when you look at the way
the programs are structured within the EPA, we are not going
there. Now, maybe in concept we are in our minds, but we are
not doing it with the way the programs are structured.
You just basically admitted yourself, you said, ``Well, I
am more involved with the Federal end.'' Well, we need people
at the Federal end involved with the State and local end and
vice-versa or we are never going to understand these things and
we are never going to get there.
I think we have to get out of the box and start getting
into the 21st century here. When we started, and Senator
Moynihan referred to it, I believe, in his comments, you know,
in the 1960's and 1970's environmental regulations were out of
desperation. We needed it. We were polluting the air, the land,
and the water.
Now, though, we have made significant progress in that
regard. I think it behooves us now to take these resources and
focus them on the most immediate list and work down the list
and prioritize them the same as you do your household budget.
You might be planning a vacation, but if your car breaks down,
then there goes the vacation money. You have to fix the car. We
make priorities. We make decisions. We are not doing that now.
We are out there throwing what we think is our unlimited
dollars at these various problems and seldom prioritizing in a
way that we could get some of the most immediate health threats
and environmental problems out of the way.
I don't think we are ever going to get there if we don't do
that. We are assuming that we have so many resources that we
could just do it all. That would be nice. Maybe we will get it
all at some point. I think before that we need to get to the
point where we can start the prioritization process and cleanup
the most serious problems first.
As I say, in all due respect, I don't think that is
happening really in terms of the way the programs are
structured in the EPA.
Senator Baucus, I was just about to leave this panel, but
if you have questions, go right ahead.
Senator Baucus. Well, I would like to followup on the
resource question. What do we need to do an adequate job? To me
risk assessment and the threat of risk assessment is a good
tool. As I mentioned, it makes sense. I am informed and
certainly GAO has concluded that perhaps we could use more
resources. But that sort of begs the question in my mind of how
much is enough.
Mr. Guerrero. I think the resources have to follow a
coherent strategy and justification for why those resources are
needed. The Agency needs to have a strategy that says, these
are the key areas of data that we need to have to be able to
set risks and to be able to compare risks and make better
informed decisions and here is the schedule on which we need to
develop that to support this type of decisionmaking and here
are the resources that will be required to fill in those gaps
and to make our systems more compatible with one another and to
allow us to answer these kinds of questions.
So, when we observed there were these barriers standing in
the way of the Agency using risk management to help set
priorities, we don't necessarily say, ``Well, it is going to
take X or Y dollars to do that.'' I think what is key in here
is the Agency having a good, well-founded plan and strategy for
what it needs to do to move this process along. That is what is
missing.
Senator Baucus. Mr. McGartland, do you agree?
Mr. McGartland. I think we do need more data clearly. Data
is very expensive to obtain. I think I mentioned the
toxicological data we need from animal studies. The majority of
the chemicals are not yet complete in their risk assessments.
Without completion of those things, it is hard to do risk
assessment if we don't have the underlying data base to support
the toxicology and the epidemiology.
The Agency recently created Office of Environmental
Information. It is the first time in the Agency's history we
have had a centralized environmental information office. I know
that they have taken on a number of interesting, innovative
steps, in addition to having a unique facility identifier for
every facility in the country so that we can link cross-media
data bases, et cetera.
Senator Baucus. Having heard Mr. Guerrero suggest we need a
schedule, do you agree with that?
Mr. McGartland. I think a schedule would help. I think if
we have clear needs that have been outlined and conversations
with GAO and others. We could identify the low-hanging fruit in
areas where we can't do our business currently.
Senator Baucus. What would some of those areas be?
Mr. McGartland. The underlying toxicological data to
support the risk assessments of the Agency. I think there is
monitoring data for painting a picture of the current baseline
of the environment both in the water area and the air area and
the other media. I think I would probably start with that. As
an analyst, that is the kind of value that you need to think
about, benefits and costs and what we are going to buy for
future regulations.
Senator Baucus. Mr. Guerrero, could you suggest some
elements of a schedule or what areas? Can we break this down a
bit?
Mr. Gurrero. We didn't make very specific recommendations
as to specifically which areas. We did observe that there are a
number of gaps. The EPA's integrated risk information system
lacks basic toxicity data for two-thirds of the known hazardous
air pollutants. So this is a key area.
The limited monitoring of the Nation's waterways to assess
the quality of lakes, rivers, streams and shorelines is another
area. We recently issued a report where we observed that for
some 1450-odd toxic chemicals we reviewed, actual human
exposure data were being collected for only about 6 percent of
those.
So, there certainly is enough information out there from
the work we have done and from the work the SAB has done to
help the Agency and guide it in terms of setting these kinds of
priorities.
Senator Baucus. Do States collect much data that is
helpful?
Mr. Guerrero. Yes, they do. In fact, not only do the States
collect information but also sometimes information that might
be valuable could be collected at the local level from public
health agencies and sometimes it can be collected from other
Federal agencies.
Senator Baucus. How reliable is it?
Mr. Guerrero. Well, that is the key. What is needed here,
as EPA develops this strategy for producing a more complete
understanding of environmental conditions and risks, is a
strategy to identify how it will bring in these other sources
of information and how we will ensure the reliability of that
data.
We do know from the work that we have done that there are
concerns that some of the State-developed information is not
that reliable and needs to be improved. The Agency needs to
work with the States in that regard.
Senator Baucus. Is there any protocol problem here? You
know, one State might collect data a certain way----
Mr. Guerrero. Yes, and the Agency recognizing that, is
developing data quality standards and will be working with the
States.
Senator Baucus. How much variation is there today?
Mr. Guerrero. There is some variation. The variation
depends on the results of different frequencies in which
different States may sample for different water quality
standards. They may be sampling using different protocols. All
of these issues need to be addressed in terms of improving data
quality.
Senator Baucus. To me it seems like a gargantuan task. For
example, let us take a very parochial example in my State of
Montana. I assume the health agencies obtain data with respect
to infectious diseases. It turns out that is not the problem
for this one community living in Montana, rather it is
contamination from an asbestos mine. It is just not an
infectious disease.
How do you know what to look for? It is everything. I mean,
you need a super, super, super computer, it seems to me, of
some kind. I guess I don't know this very well and I am showing
my ignorance. But, in theory it is great. I guess as I was
saying earlier, you just have to know its limitations.
Mr. Guerrero. Well, we certainly wouldn't recommend that
the Agency kind of throw a blanket over this issue and try to
collect everything you could possibly collect. This has to be a
targeted, focused effort. That is why, again, I come back again
to what we recommended to the Agency. Who is coming up with a
strategy? Because it does need to set priorities. It needs to
identify key areas where information is critical for making the
major decisions it will have to make over the next few years.
Senator Baucus. Is anybody working on setting up the
strategy?
Mr. Guerrero. Yes. Unfortunately, it is going much slower
than we would like to see. The Agency tells us now it will be a
three-phase effort and the first phase will be completed at the
end of this year.
So, the good news is yes, the Agency is working on
developing this kind of strategy which, in our opinion, it
desperately needs. The bad news is it seems like it is going to
take a long while to get there.
Senator Baucus. So, we don't know what the strategy is?
Mr. Guerrero. We haven't seen it. We don't know it.
Senator Baucus. So, we have to be as careful as we can to
comment whether it makes sense or doesn't make sense because
there isn't one.
Mr. Guerrero. That is right. What I would urge the Congress
to do is to continue to oversee the Agency's efforts in this
area.
Senator Baucus. Absolutely. Thank you.
Thank you, Mr. Chairman.
Senator Smith. I would just say as a final point, does the
EPA make decisions with data or without data? I mean, that is
the issue, isn't it? Are you using the data to make your
decisions or are you not using the data and making decisions
anyway?
Mr. McGartland. Well, it is a continuum, of course. There
is always something in the limit or in the most simplistic
cases where we lack the capability to estimate benefits or
risks.
We can usually get a very good handle or a reasonable
handle on costs and exposure in some sense from experts and
what literature exists on the chemical, about the reasonable
toxicity, relative toxicity of that chemical vis-a-vis other
chemicals. That would be the limited case in terms of a
regulatory proposal.
When we had the benefit of a rich epidemiological database
or if we actually have human data, et cetera, we are obviously
on much surer footing when we move forward in quantifying our
benefits. Probably even on the cost side a dearth of data
exists.
The Census Bureau used to do a survey called the Pollution
Abatement, Control and Expenditure Survey every year, which
gave it a handle on how much industry was spending on pollution
abatement. They canceled that survey due to budget cuts or re-
priorities.
So, we are equally challenged on the cost side and are
taking steps, I think, to get a handle on that as well.
Senator Baucus. This, to me, is just so important, the
resources for the data. My State of Montana, 20 years ago, we
got a multi-year baseline data EPA appropriation. It is the
best thing we ever did because we are then in a position to
know what different actions would have on, say, Flathead Lake,
MT, in that area, whether it was Forest Service actions or
Glacier park nearby or Canada with the potential coal power
plants or coal mines.
We had the baseline data, so we could measure what the
effects of some actions on the rivers and lakes would be. I
just believe firmly, Mr. Chairman, it is foolhardy when this
Congress prevents agencies from having the funds and the
resources they need to get this data.
Some of it is priorities of the Agency, but I must say I
think some of it is kind of Luddite-like of the way that
Congress just doesn't want to know. One way you don't want to
know is just don't give money to let them find out. I strongly
urge all of us together to help in that regard.
Senator Smith. Well, we thank the panel. There could be
questions submitted to you by other members. We will be keeping
the record open until the close of business Friday for that.
Thank you, Mr. McGartland and Mr. Guerrero.
We will call up the next panel please.
Senator Baucus. Mr. Chairman, I ask consent to have Senator
Moynihan's full statement included in the record.
Senator Smith. Without objection.
Senator Smith. Panel II consists of Ms. Katherine Hartnett,
executive director of the New Hampshire Comparative Risk
Project; Mr. Michael J. Pompili, assistant health commissioner,
Columbus Health Department; J. Clarence Davies, Ph.D., senior
fellow, Center for Risk Management, Resources for the Future,
Dr. Elizabeth L. Anderson, president and CEO of Sciences
International, Inc.; and Dr. Morton Lippman, professor, New
York University, chair of the Science Advisory Board.
Welcome to all of you. Your statements will be made part of
the record and I will just go down the table from left to
right. We will start with Ms. Hartnett. Since your statements
will be part of the record, please try to summarize in 4 or 5
minutes, if you can, please.
STATEMENT OF KATHERINE HARTNETT, EXECUTIVE DIRECTOR, NEW
HAMPSHIRE COMPARATIVE RISK PROJECT
Ms. Hartnett. Good morning. Thank you very much. I
apologize for my voice. I think it will last 5 minutes.
Senator Smith. Excuse me for interrupting you, Ms.
Hartnett. But we are going to have to slightly modify our usual
process for hearings because the Minority has invoked what has
been called the 2-hour rule. Senate Rule 26.5(a) prohibits a
Senate committee from conducting business for more than 2 hours
past the time that the Senate begins its daily session, which
means we can only go until 11:30.
But Senator Baucus and I have agreed that the rule doesn't
prohibit the committee from conducting informational meetings
so we will try to do what we can on the record until 11:30, but
if the Minority does invoke the rule at 11:30, we will adjourn
and reconvene briefly for an informational meeting rather than
an official hearing.
Should that happen, it would have no impact on the
witnesses. They would still be allowed to present that
testimony as well as any additional materials.
At a later date when the committee is conducting business,
we will see a unanimous consent order to take the transcript of
that meeting and put it in as part of the official record.
I am sorry, Ms. Hartnett, go ahead.
Ms. Hartnett. Thank you very much. I apologize for my
voice. I have been talking too much and on too many airplanes
recently.
My name is Katherine Hartnett. I am executive director of
the New Hampshire Comparative Risk Project. It is a public-
private partnership in New Hampshire; very different than some
of the models we have heard about.
My job today is to condense 7 years worth of work into 5
minutes. Fortunately, most is conveyed in this book, which I
believe everybody has copies. The Comparative Risk Project in
New Hampshire focused on environmental quality of life and
hazards to that environmental quality of life as the focus of
our comparative risk process.
We identified ``environmental quality of life'' as an
intersection of healthy people, healthy ecology, and healthy
economy. After a year of talking about our results, we
condensed the information down to 26 pages. So, most of the
actual process that I am going to talk about is contained in
this book called, ``For our Future: Our Guide to Caring for New
Hampshire's Environment.''
The other thing I will observe is that we couldn't agree
more with Senator Moynihan. What really has happened is that
there has been a maturing of the environmental movement. In
fact in New Hampshire we are recognizing the economic root of
most of the environmental issues that we face. In the next few
minutes I will describe how we got there.
We agreed at the beginning of the Comparative Risk Project
our goal was to maximize environmental protection at minimal
cost--this was back in 1993. We wanted to separate fear from
hazard to try to more effectively prioritize actions.
We looked for solutions that would benefit multiple
problems. We wanted to design approaches that productively
engage multiple constituencies and showed results. We recognize
that everyone has a role in this process.
The Comparative Risk Project worked. We identified 55
stakeholders from businesses, environmental organizations,
public health groups, citizen groups, political leaders, State
and local government officials. We all gathered in a neutral,
non-advocacy setting. We worked to identify, to study, and to
rank identified risks to environmental quality of life.
We had technical staff that summarized ecological, public
health and economic information in a consistent format with
consistent criteria. The group worked by consensus over 8
daylong sessions. The work was important, so it took a while to
do. We did rank into an integrated list 55 risks to New
Hampshire's environmental quality of life as I defined,
``Healthy people, healthy ecology and healthy economy.''
We documented the influence of accessible science condensed
in this Comparative Risk Project report along with explicit
judgment and individual values in the ranking.
We basically designed what has been recognized as quite a
credible process. The diverse participants had three
requirements: Leave preconceptions at the door, be able to
listen to others and work collaboratively, and finally to bring
a sense of humor to difficult discussions.
It was important for people to set aside what they knew and
listen to the information from a different perspective. By
putting environmental quality of life at the center, it allowed
us to focus on the intersection of having all three things
together: healthy people, healthy ecology, and healthy economy.
We have created a continuum of hazard from relatively
higher to lower. The common vocabulary of the severity, the
extent, the reversibility, and the uncertainty of individual
risks helped this group of diverse people come to some
consensus about how those risks were allocated along the
continuum of hazard.
We also recognized the long term, meaning 7- to 10-year
nature, of the solutions we were talking about.
Now, basically, what we did when we came up with the list
of ranked risks, as we began to separate fear from hazard, was
to recognize that while 4 of the top 10 risks in the integrated
list were risks to public health, 4 of the top 5 were related
to threats of air and water quality.
We then traced those 55 risks back to 11 sources, things
like energy use, land use, transportation, recreation, food and
water.
We identified four key actions to reduce hazard in New
Hampshire. Those four were: (1) to continue work on improving
public health in New Hampshire--we found that people were
living longer healthier lives for a variety of reasons. (2) to
continue to reduce releases of pollutants. That is thanks to
everything from NEPA, the Clean Air Act, Clean Water Act, Safe
Drinking Water Act, RCRA, CERCLA, and SARA. Between 1970 and
1986, the range of Federal and the equivalent State regulations
have been successful. After 30 years of regulation, the air,
water and land are quite clean and the economy never stronger.
So, in New Hampshire we are focusing now on something
called ``Minimum Impact Development.'' We are looking at (3)
how we use land; and (4) how we use energy materials and
resources.
In terms of comments to Congress based on our experience,
we suggest that there may be an opportunity here for Congress
to take credit for the work it has done to date, that the
regulations that came during the first generation of
environmentalists have been successful. Why not take the time
to celebrate those successes, and to recognize also that the
current set of environmental hazards we face will probably not
be solved by any one regulation or group of regulations.
The challenge today is more difficult. There are not clear
villains or easy solutions. Everyone is involved, at work, at
home, and how we recreate. Information and clear understandings
are essential. Why not take the time to convene annual
hearings? Ask for consistent information.
We heard about the important role of data on regional and
local conditions. Try to incentivize good data. Then work on
developing an action plan to support the work of State and
local communities, encouraging community-based solutions
informed with accessible data and supported by sufficient
funding.
Certainly examples that EPA has been involved in a little
bit out of the ``stovepipe'' or ``box'' might be things such as
is currently funding my work under the Sustainable Development
Challenge Grant, or the CARA legislation is another example
that relates directly to our experience in New Hampshire.
Also, I must mention the essential role of transportation
and the question of how we maintain mobility as we grow to
greater density in the State. It plays a key role in our
economic activity, and can also then be traced back to a wide
range of environmental hazards or environmental benefits,
depending on how we answer those questions.
So, in short, a key Federal environmental role can be to
stimulate, requiring consistent regional and local information
about environmental conditions and trends to assemble a
national picture and then support a wide variety of actions
based on those data.
We would love to see annual deliberations that encourage
results-oriented environmental quality, use environmental
indicators as measures of progress, and link agency budgets to
reducing environmental impacts.
The key role of getting citizens involved, getting results
and seeing the effects of Federal support on the ground would
be a true legacy for the second generation of environmental
management.
Thank you.
Senator Smith. Thank you, Ms. Hartnett.
Mr. Michael J. Pompili.
STATEMENT OF MICHAEL J. POMPILI, ASSISTANT HEALTH COMMISSIONER,
COLUMBUS HEALTH DEPARTMENT, COLUMBUS, OH
Mr. Pompili. Good morning, Chairman Smith and members of
the committee. It is an honor to provide testimony to you this
morning, particularly on a process which I strongly believe in
and which has been central to several programs which have been
developed for the Columbus community over the past 10 years.
Your willingness to discuss the use of comparative risk
assessment in setting community priorities demonstrates your
understanding that there are no simple answers to solving
environmental issues that the impact on our communities and
that it is critical to involve the stakeholders in the process.
During the next few minutes of testimony, it is my goal to
share with you how we have successfully implemented several
comparative risk processes in Columbus, to identify the central
themes which have led to the success of these efforts and to
make some recommendations.
This all started with a Community Environmental Management
Plan, which was established through the Columbus Health
Department in 1992. It is made up of five components. The first
component was actually based on the Science Advisory Board from
U.S. EPA. We have established an Environmental Science Advisory
Committee; we call it ESAC, which is a body of 18 environmental
scientists, educators and other professionals that report back
to us on scientific issues.
The second component was Priorities 1995. It was our
comparative risk project. It took over 2 years and it is a
classic example of comparative risk assessment. For this we
used over 250 community volunteers and they logged over 5,000
hours to come up with a list of actually 192 recommendations
for our community.
They identified the city's most pressing environmental
problems, analyzed and determined potential risks to citizens,
ranked these problems in terms of severity and then developed
potential solutions to these problems.
The third component is called our Columbus Environmental
Snapshot. They use key indicators to provide the public with
status and trend information on the State of Columbus and
Franklin County environmental issues.
In creating the snapshot, the objective was to compile
information already being collected by numerous governmental
organizations into a single, easy-to-understand and user-
friendly document. The information contained in the snapshot
represents both an educational resource and a means of gauging
the success of past environmental efforts including status
reports on Priorities 1995.
The fourth component, which we started actually in February
1998, was the Columbus Community Risk Panel. It is a 35-member
community designed to help Greater Columbus residents make
informed decisions about risk.
The panel, through various initiatives, serves as an
ongoing research to help develop a more informed citizenry and
provide the community with accurate information on health and
quality of life risks. Panel members again include public
officials, community leaders from government, professional
groups, public and private business, health care and
educational organizations and the media.
A key goal of the panel is to establish connections with
citizens. This is accomplished through a variety of projects
including establishment of community computer centers in
African-American churches, the Neighbor-to-Neighbor Program,
formation of Community Advisory Panels that bring industrial
facilities and neighborhood groups together and establishing a
Web site for risk information.
The last component is called Project CLEAR, which is a new
citizen-driven initiative based on the same principles as our
Priorities 1995 Risk Project. It is designed to address Central
Ohio's outdoor air quality, particularly issues related to
ground-level ozone pollution.
CLEAR's main objective is to involve citizens, businesses,
local governments, and other organizations in evaluating and
choosing strategies to improve overall air quality. What is
particularly unique about Project CLEAR is that it moves beyond
the public opinion forum into a more public deliberation
process.
Three basic principles underlie all the components of the
Community Environmental Management Plan. First, promoting the
use of science and scientific information wherever possible,
second, developed a more informed citizenry on issues of
community health, environment and quality of life, and finally,
encouraging public participation in the decisionmaking process.
These principles have not only led to the success of our
efforts, but are appropriate at all levels of government,
local, State and Federal.
An excellent example of these principles operationalized at
the State level was when Senator Voinovich, then Governor
Voinovich, embarked on a comparative risk project for the State
of Ohio. Similar efforts have been conducted by 25 of the 50
States as well as at least 12 local communities.
The process represents a new way of doing things most
importantly involving the public in meaningful ways.
So, the question remains, what role can the Federal
Government play in this effort? The Federal Government's role
is to establish national priorities. The use of a national
comparative risk process could provide general direction in
setting these national priorities, but it is important to
understand the limitations of a Federal comparative risk
project.
A Federal comparative risk project is doomed to fail
because risks encountered in Florida aren't compared to the
risks found in Oregon. Instead, it would be most appropriate
for the Federal Government to support these efforts on a State
and local level and actively promote the principles of sound
science and informed citizenry and public participation.
Specifically, the Federal Government can serve as a
technical assistance center, both generating data and
fulfilling the role of information resource. State and local
communities will vary widely in their ability to successfully
implement a comparative risk project.
Federal support and technical guidance may allow for at
least some degree of consistency and utility of effort. Because
community participation and buy-in are critical in these types
of initiatives and central for any behavioral change to occur
on the part of the individuals, Federal emphasis and support
for community participation at the local level may also be
appropriate.
Shifting from categorical-thinking formulas to community-
thinking formulas will go a long way toward promoting
involvement.
Further, it would be helpful for States and local
communities to look to the Federal Government for funding of
comparative risk projects or at least linking to the available
funding for such efforts.
Some of what I have described is not necessarily a new
role. At one time the Federal Government funded a U.S. EPA
office to directly assist State and local folks interested in
doing this type of work.
The Regional Statistical Planning Branch of the Office of
Policy Planning and Evaluation was extremely helpful to us in
Columbus, providing a $50,000 grant for our project and direct
technical assistance and project formation and implementation.
I have heard many other local project directors share these
sentiments. Unfortunately, the office was disbanded a year or
so ago and the personnel were reassigned within the Agency. To
my knowledge, there is no Federal entity that exists concerned
with promoting and directly assisting State and local
governments with projects dealing with risk-based
decisionmaking.
By recognizing the value of local communities in
determining their priorities, a further role for the Federal
Government is flexibility. While Federal standards and
regulations are often warranted, it is important to allow for
some tailoring of the effort according to local community's
needs.
U.S. EPA's Project XL is a perfect example of this type of
philosophy. In its current form, however, Project XL is
somewhat cumbersome and a challenge to negotiate. We are quite
pleased to have just signed the final agreement for an XL
Project in Columbus, actually a week ago today an effort which
took over 3 years to finalize.
In asking for flexibility, however, local communities need
to hold themselves accountable and maintain, if not higher,
standards that those set forth at the Federal level.
If by your flexibility at the Federal level you are
demonstrating your trust of the State and local government to
make sound environmental decisions, we must safeguard this
trust and work cooperatively with you toward common goals.
Without a certain level of trust at all levels of
government, even the most innovative programs are doomed to
fail.
In closing, let me once again reiterate the importance of
public participation and connecting with our citizenry. More
and more of our citizenry are expressing dissatisfaction or
disinterest in civic responsibility.
While they are disengaging from the political process, you
must fight to have them actively involved in directing
resources and actions that will impact their own neighborhood
and their quality of life.
We must demonstrate government's trust in the ability of
the residents to make these programs work. I am a very strong
believer that our citizenry will make the right decisions.
If they are able to receive information in an
understandable way, if they are presented with accurate
portrayals of the existing tradeoffs regarding risks, and if
the decisionmaking process reinforces the need to consider a
whole range of options available.
If these themes maybe woven through the Federal, State and
local government we may yet see a public which still seeks out
their civic roles.
Thank you.
Senator Smith. Thank you very much, Mr. Pompili.
Dr. Davies, welcome.
STATEMENT OF J. CLARENCE DAVIES, SENIOR FELLOW, CENTER FOR RISK
MANAGEMENT, RESOURCES FOR THE FUTURE.
Mr. Davies. Thank you, Mr. Chairman. I am pleased and
honored to be able to share with the committee my views on the
important subject of comparative risk assessment. My views are
only my views and do not represent RF's views. Resources for
the Future is a research institution that doesn't take
positions on public policy issues.
Comparative risk assessment is an important analytical tool
that deserves the attention this committee is giving to it. The
fundamental goal of most of our environmental programs is to
reduce or prevent risk, thus identifying and comparing risks is
a logical starting point for evaluating progress and
identifying future directions and priorities.
There are, however, important limitations inherent in the
use of comparative risk assessment. Most importantly, we have
no common metric to deal with the diverse kinds of risks that
government addresses. When I was at EPA, we referred to this as
the ``How many whales is your grandmother worth'' problem. The
problem was how do you get some comparability among very
diverse end points.
I might say that just dividing health risks from ecological
risks doesn't solve that problem. Different kinds of health
risks, different kinds of ecological risks present the same
problem of how do you get some kind of common measurement to
compare these things.
There are answers that can be given to these questions, but
the answers are heavily dependent on values. Even if scientific
understanding was perfect and data were complete and accurate,
the value elements inherent in CRA would prevent comparative
risk assessment from ever being a purely scientific
undertaking.
The science and the data in most cases are woefully
incomplete. Other witnesses have commented on that. This adds
further elements of uncertainty and value judgment to
comparative risk.
There are different kinds of comparative risk assessment
and it is important to make some distinctions among them. In
particular, there is a basic difference between comparing
individual pollutants or activities and comparing programs.
Comparing mercury to lead is very different from comparing
air pollution to water pollution. You use different methods and
different approaches to do those two different things. That
doesn't make life any simpler, but it is true.
This hearing is focused primarily on programmatic
comparative risk assessment and it is important to keep that in
mind.
More generally, the type of comparative risk assessment
undertaken and the process used to make the comparisons should
depend on the purpose for which the comparative risk assessment
is being done. Doing a comparative risk assessment to establish
research priorities involves quite different considerations
than doing one to establish enforcement priorities, for
example. So, the kind of priorities that you are working with
is a crucial factor.
In my written statement I talk about various uses of
comparative risk. I am going to skip over that, but there are a
number of uses to which comparative risk assessment can be
employed and they are important and it is an essential tool.
I do want to talk a bit about the limitations of
comparative risk assessment. As I noted, the assumptions and
values that unavoidably enter into both risk assessment and
comparative risk assessment are major considerations. Risk
assessment is an odd mixture of science, non-science, and
comparative risk assessment necessarily suffers from all the
limitations of risk assessment.
CRA suffers from additional methodological problems. For
example, how should the risk reduction effect of current
efforts be considered? If there were no public program to
protect drinking water in this country, drinking water would
rank among the highest risks, as it does in many developing
countries. However, because we do have protection programs in
place, the current risks from drinking water in the United
States are not great.
In the context of budgeting, for example, how to deal with
existing efforts poses difficulties for comparative risk. We
cannot do zero-based budgeting, in a sense, because on a zero-
based budget you would have nothing protecting drinking water
and that would be a very high risk, but it is a very low risk
if you just look at the risks at the present time. So, taking
into account current efforts is a major methodological problem.
Most importantly, comparative risk assessment deals only
with risk and risk is only one of several factors that enter
into most government decisions. Again, other witnesses have
commented on this, but cost is an obvious factor.
To the extent that decisions should be based on cost-
benefit analysis, risk is only the benefit side of the
equation. You somehow have to get cost in there as well.
Furthermore, you cannot do a cost-benefit analysis of a
problem, only of a solution. Whereas comparative risk
assessment deals with problems--air pollution, water pollution,
cost-benefit deals with solutions--inspecting automobiles,
installing technology in plants and so on.
So you are dealing with two different universes of things
when you deal on the one hand with cost-benefit analysis and on
the other hand with comparative risk assessment. Getting from
one type of analysis, comparative risk, to the other, cost-
benefit, is not simple because you are analyzing two distinct
sets of things.
Let me note a few other limitations. First, how the
comparative risk assessment is done can have an important
effect on the outcome. A paper by my colleague, David Konisky,
which I would like to submit for the record, demonstrates that
problem. How broadly you define the categories makes a big
difference in how you rank the risk.
Second, how to involve the public. Mr. Pompili is
absolutely right about the critical importance of involving the
public. But that means you have to resolve how you combine
technical scientific information with the information that the
public brings to bear.
Then, finally, the data problem, which has been commented
on extensively. Let me simply say that in terms of the
committee's tasks, I think the time is long overdue to create a
Bureau of Environmental Statistics, comparable to the Bureau of
Labor Statistics or the Center for Health Statistics. We need
that. There is no such institution in the environmental area.
It would be a major step forward, both in terms of improving
the amount and the quality of data. We have no central place to
look to for environmental statistics and we need one.
The statutory context makes a big difference. In my written
testimony I make several comments about it. Let me just second
the comments you made, Mr. Chairman, with regard to the
problems of stove piping.
However, let me say that in my view as long as the statutes
are drafted in a stovepipe fashion, the Agency cannot organize
in any other way than by stovepipe. The stovepipe, medium-by-
medium organization is a major impediment to doing comparative
risk assessment. It is also a major impediment to data
collection.
In the long run we need an integrated single environmental
statute. That is the only way we can overcome the stovepipe
problem.
In fact, the United States, in a decade or so is going to
be one of the few industrialized countries left that doesn't
have an integrated environmental statute. The Europeans, the
Scandinavians, a number of countries have already gone in that
direction of integrated environmental statutes. The United
States is going to have to face up to that sooner or later.
Let me conclude by saying that despite its limitations,
comparative risk assessment is a valuable analytical tool. It
may be most useful for the questions it raises and as a way of
initiating a process leading to more transparent and defensible
decisionmaking. How well it serves these functions will depend
heavily on whether Congress itself asks for relevant risk
information and uses the answers in its budgetary, oversight
and legislative actions.
Thank you, Mr. Chairman.
Senator Smith. Thank you very much, Dr. Davies.
Dr. Anderson, welcome.
STATEMENT OF ELIZABETH L. ANDERSON, PRESIDENT AND CEO, SCIENCES
INTERNATIONAL, INC.
Ms. Anderson. Good morning. I am pleased to be invited by
this committee to testify on the important issues of risk
assessment, particularly as they are involved in two programs
of focus today: The Comparative Risk Program and the Residual
Risk Program.
My name is Elizabeth Anderson. I am president of Sciences
International, an organization that specializes in the health
and environmental sciences.
Previously, I was privileged to be involved in founding and
directing the first EPA's carcinogen assessment group.
Subsequently, I also directed the expanded office, the Office
of Health and Environmental Assessment, where I had the
opportunity to essentially direct the Agency's central risk
assessment programs for 10 years.
I was also the executive director of the committee that
first adopted risk assessment and risk management as a process
for regulating environmental toxicants.
Subsequently, this committee wrote the first agency's risk
assessment guidelines. I have been involved for many years with
the Society for Risk Analysis as a founder, past president and
currently editor-in-chief of the society's flagship journal,
``Risk Analysis: An International Journal,'' that serves as an
international focal point for developments in risk analysis.
Obviously, a principal focus and interest of mine is
improvement in the sciences supporting risk assessment. Two
important applications of risk assessment that we are
discussing today, the comparative risk assessment program and
EPA's Residual Risk Program are of great importance and must
rely on the tools of risk assessment.
In the case of comparative risk, we are comparing human
health and environmental risk across many programs and many
media to set priorities to assist informed decisionmaking. In
the Residual Risk Program the regulatory requirement is to
assess residual risk in a relatively short period of time
following the application--that is 8 years after the
application--of maximum achievable control technologies across
all of the major industry categories.
Today, I want to discuss essentially the important progress
and the importance risk assessment has to these activities. The
details of my testimony are presented in my written statement,
which thoroughly explores these topics.
I will summarize that testimony by focusing on the five
areas that I have selected as the principal focus for my
recommendations.
First, the complexity and cost of conducting risk
assessments called for by Comparative Risk and the Residual
Risk Programs is really unprecedented. For example, when we
think of the Residual Risk Program, we are speaking of 188
hazardous air pollutants that must be evaluated for 175 source
categories involving literally thousands of facilities. This
must be done in a relatively short period of time.
Even more toxic pollutants and sources must be considered
in the Comparative Risk Program. The previous experience with
programs such as this has been limited. Let me just mention
this because I think it is very important. We are considering
individual and population risk and ecological risk in multi-
pathway risk assessments across many industries, facilities,
and pathways.
The prior experience with these kinds of comprehensive risk
assessments has been with individual Superfund sites and
individual facilities that are combustion sources, not these
comprehensive source categories. So, this is an enormous
challenge.
My recommendation is that we must have a thoroughly
disciplined tiered approach that everyone subscribes to. The
first tier would certainly employ the best available data, but
would be recognized as a screening level assessment.
For those sources that have low risk, obviously, no further
work needs to be done. For the sources that appear to be posing
a risk of any concern, the next tier would involve a
sensitivity analysis to focus on gathering data for the most
important parameters to express risks more accurately.
Resources necessary to conduct these risk assessments both
within EPA and on the part of involved parties needs to be
recognized. In addition, I see no way that these risk
assessments can really be refined without a partnership with
the involved source categories.
EPA's current draft guidelines for this tiered approach
really fall far short of specifying this kind of disciplined
approach and following the steps that I have laid out in my
testimony. That is, to have the initial upper-bound risks serve
a screening purpose, but then to very clearly articulate what
kind of risk assessment steps would follow and under what
guidelines and when they would be triggered.
Second, I wanted to identify several policy issues that
these two programs essentially require for clarification.
Historically, EPA has limited its risk assessment guidance for
hazardous air pollutants to carcinogens, inhalation risks, and
risks to individuals, but has not addressed how judgments will
be made about multi-pathway risks and how broader population
risks will be considered.
Further, language in the 1990 Clean Air Act Amendments for
residual risks states that environmental risks must also be
considered, there is some very specific language.
How these policy issues will be considered under the
Residual Risk Program must be clearly articulated. There should
be an opportunity, clearly, for public involvement and comment
before arriving at final criteria for identifying risks of
concern.
Third, emissions data must be substantially improved.
Historically, EPA has used the readily available emissions data
that it has. Often these are estimated values rather than more
precise measured, post-regulatory emission values.
The risk assessment can be no more accurate than the
emissions that are used in the dispersion model. I recommend
that in the second iteration these emissions data be improved.
Again, I see no way of improving these data without a
partnership with the organization and facilities that have the
best emissions information.
Fourth, the integrated risk system, the IRIS data base, as
a repository of regulatory toxicity values must be revised. The
risk assessment forum for which I was the first director, set
up the IRIS data base and commenced the stewardship program of
employing information readily available in the Agency to
establish this data base principally to ensure consistency
across the regulatory programs and to share information.
It was really not intended as a direct use for regulatory
decisions. Since that time the IRIS data base has become not
only the most important source of regulatory toxicity values
for all of EPA's programs, but it is widely used by State and
international programs as well.
The IRIS files include over 500 chemicals. Many of these
are woefully out of date. I have discussed a number of these
issues in my written testimony. My recommendation is that for
the identified 188 air toxic chemicals, refinements in the
toxicity issues need to be revisited as a part of the Tier 2
risk assessment process. The same concept need to be entered
into refinement for the Comparative Risk Programs.
I recommend, as everyone else does, that the resources need
to be committed to EPA to update all of the over 500 chemicals
in the IRIS file and to maintain this data base in a refined
and up-to-date status.
In making this recommendation, however, I recognize that it
is an almost impossible task. Nevertheless, I think all efforts
should be made to carry it out. To be totally practical, I
further recommend that the preface to the IRIS date base be
restated to recognize reality.
That is that the data base can probably never be a current
source of all the latest information in the literature with
application of the latest risk assessment methodologies
necessary to assure accuracy in risk assessment for risk
management decisions.
Finally, uncertainty and variability analysis must be
applied more explicitly. Historically, EPA has come to
recognize the importance of performing variability and
uncertainty analysis, but to date the Agency has been able to
do so for a very limited number of parameters used in the risk
assessment.
This process needs to be extended to address all parameter
categories. However limited or precise the uncertainty analysis
and the variability analysis may be though, it is not clear
what, if any, role these analysis play in the risk management
process.
I recommend that there be clear guidelines developed for
the use of uncertainty and variability analysis in making
management decisions. I have suggested some ways of doing this
in my written testimony.
Finally, I think risk assessment is an exceedingly valuable
tool. The underlying sciences have been greatly improved since
they were first employed in 1976. I believe progress will
continue and these processes can provide the essential bases
for risk-based management decisions.
Thank you.
Senator Smith. Thank you very much, Dr. Anderson.
Before turning to you, Dr. Lippman, I am going to have to
implement the rule. It will not mean that your testimony will
not be officially received at some point, but it will be
informational for the purpose of today.
Because of the Senate Rule 26.5 (a) being called for by the
Minority, this does prohibit any committee from meeting beyond
the 2-hours after the Senate goes into session. As I indicated
earlier, Senator Baucus and I have agreed to adjourn and go
back to an informational meeting, which I will do in just a
second.
At some point in the future we will ask unanimous consent
of the committee to make this part of the record. So, I would
just say to the Clerk, just be prepared to make that indication
when we have the unanimous consent agreement.
So, at this point I am going to adjourn the hearing.
[Whereupon, at 11:33 a.m., the committee adjourned, to
reconvene at the call of the chair.]
COMPARATIVE RISK ASSESSMENT: SCIENCE ADVISORY BOARD'S RESIDUAL RISK
REPORT--INFORMATIONAL MEETING
----------
TUESDAY, OCTOBER 3, 2000
U.S. Senate,
Committee on Environment and Public Works,
Washington, DC.
The committee reconvened outside of the regular order at
11:33 a.m. in room 406, Senate Dirksen Building.
Present: Senators Smith, Inhofe, and Baucus.
Senator Smith. I will now call this informational meeting
to order.
Our next witness is Dr. Morton Lippmann, chairman of the
Science Advisory Board.
STATEMENT OF MORTON LIPPMANN, PROFESSOR, NEW YORK UNIVERSITY,
CHAIR, SCIENCE ADVISORY BOARD
Mr. Lippman. Mr. Chairman, I appreciate the opportunity to
offer information on the scientific basis for the current
limitations of and opportunities for future improvements in
quantitative risk assessment as a tool for environmental risk
management.
This hearing is focused on the capabilities and limitations
of current knowledge and technical means of comparative risk
assessment in the roles of guiding new legislative mandates,
societal choices and individual decisions based on risk
avoidance.
In my remarks I will focus on health risks associated with
exposure to air-borne chemicals and mixtures thereof in our
communities.
In order to determine the extent of any health risk
existing among members of the population resulting from the
inhalation of air-borne chemicals, we need to know: (1) the
concentrations of the agents in the air and for particles,
their particle size distribution; (2) the unit risk factor,
that is the number of cases and/or the extent of any adverse
effects associated with the risk exposure. We may also need to
know more about the population of concern, such as the
distributions of ages, preexisting diseases, predisposing
factors for illness such as smoking, dietary deficiencies or
excesses and so forth.
Such direct comparisons can, however, only be made in
practice with any quantitative reality for a handful of
chemicals; the so-called criteria air pollutants. Their ambient
air levels are routinely monitored. Human exposure response
relationships are reasonably well known.
For the other hundreds of air-borne chemicals known
collectively as hazardous air pollutants or air toxics, there
are neither extensive ambient air concentration data nor unit
risk factors that do not heavily err on the side of safety,
which is appropriate for many of their intended uses, but not
for comparative risk.
This disparity has resulted from the different control
philosophies built into the Clean Air Act and maintained by the
EPA as part of its regulatory strategy.
Criteria pollutants come from numerous and widespread
sources, have relatively uniform concentrations across an air
shed, require State-wide and/or regional air inventories and
control strategies for source categories such as motor
vehicles, space heating, power production, et cetera.
There is also a long history of routine, mostly daily
measurements throughout the country. By contrast, HAP's sources
are considered to be definable point sources at fixed
locations. Downwind concentrations are highly variable, and
generally drop rapidly with distance from the source.
The emissions standards for hazardous air pollutants rely
on technologically-based source controls and are intended to
limit facility fence line air concentrations to those that
would not cause an adverse health defect to the most exposed
individual at the fence line.
Also, until quite recently, there has been no program for
routine measurements of air toxics in our communities. That has
just started up and there are essentially no data yet available
to analyze.
Most of the unit risk factors for air toxics are based on
cancer as the health effect of primary concern. In these
studies and in studies to assess non-cancer effects, the data
are derived from controlled exposures in laboratory animals at
maximally tolerated levels of exposure; it won't kill them
immediately.
The translation of the results from these studies, the unit
risk factors relevant to humans exposed at much, much lower
levels in the environment is inherently uncertain and has been
approached conservatively.
The resulting unit risk factors are generally based on an
assumption of no threshold and a linear extrapolation to zero
risk at zero dose. They are generally described in terms of
them being 95 percent upper bound confidence limits, but this
descriptor is undoubtedly highly conservative in itself.
When these conservative unit risk factors are used for the
prediction of the consequences of human exposure, they are
multiplied by estimates of predicted air concentrations, which
are themselves, in the almost universal absence of
measurements, almost certainly upper-bound estimates from
dispersion models that apply, really, to the most highly
exposed individuals in the community.
Dr. Hopke in Panel III will go into some more of the
limitations of this approach in the residual risk analysis.
The resulting estimates of health risk are therefore highly
conservative, upper bound levels. They are inherently
incompatible with population impacts estimated for the more
widely dispersed criteria pollutants. The margins of safety for
criteria pollutants are generally less than a factor of two,
rather than multiple orders of magnitude built into the risk
assessments for air toxins.
The highly conservative nature of unit risk factors for air
toxics is well illustrated by a calculation made during work
done for EPA during preparation of the section 812 (cost-
benefit) Study. It concluded that the imposition of the vinyl
chloride National Emission Standard for Hazardous Air
Pollutants (NESHAP) had prevented 6,000 cases of cancer.
Since the calculated cancer incidence reduction was
considerably larger than the historic incidence level of this
cancer overall, it was obvious that the benefit claim for the
imposition of the NESHAP was grossly exaggerated.
The National Research Council Committee report on
strengthening science and peer review at EPA not only
recommended the position of Deputy Administrator for Science,
it also concluded that research on risk assessment and risk
management was not only needed, but needed to be conducted by
EPA since no other Federal agency had the mandate, need or
desire to conduct such research.
Comparative risk assessment is an idea whose time is
coming. If EPA is provided with appropriate research resources
to harness the new technical approaches and sophisticated
research tools now emerging to fill key knowledge gaps, it can
make comparative risk assessment more useful and feasible in
the not too distant future.
If the recommendations in the NRC Strengthening Science at
EPA Report are adopted, the prospects for such advances will be
greatly improved. I encourage Congress to consider explicitly
giving EPA a mission statement that includes the performance of
a long-term research program focused on health and
environmental risks as a means of enhancing its capabilities
for effective and efficient stewardship of its environmental
responsibilities.
In closing, I want to thank the committee for the
invitation to testify on these important issues. I stand ready
to answer your questions.
Senator Smith. Thank you, Dr. Lippman.
Senator Inhofe will be here in a moment. He is going to
chair the last panel because I have to leave.
I am only going to ask each of you one question, if you
could respond as briefly as possible, and then I will have some
other questions for the record and I think other members may as
well.
I think many times we have witnesses here and you get the
impression that you testify and nobody listens. Congress
doesn't listen. It is all just a bunch of testimony and it goes
in the file somewhere. The truth is we do. We get a lot out of
the hearings when people come here from various disciplines and
testify before the Congress. It is very helpful to all of us in
drafting and sometimes in eliminating legislation.
Let me just start with you, Dr. Lippmann. In listening to
what you had to say, let me just ask you, here is your chance
to respond directly and give us some input. The way I read what
you are saying, you basically are saying between the lines that
EPA exaggerates risk. Is that true? Is that your position?
Mr. Lippmann. I would distinguish between criteria
pollutants and hazardous pollutants in the air environment. For
criteria pollutants, I don't think so. I think from my
experience with CASAC committees, EPA has been quite realistic
in setting NAAQS for PM and ozone that protect the public with
a very small margin of safety.
With respect to the very different tradition and ways of
approaching air toxics, the IRIS values or risk assessment
numbers have been highly conservative for historically correct
reasons. Thus, these risks in most cases are grossly
exaggerated.
In the absence of sufficient information, it will not be
conservative in every case because there are uncertainties in
the risk assessment which the safety factors protect against
adverse effects. But in most cases, clearly the cancer risks
and other risks for hazardous air pollutants will end up being
very much exaggerated. It is not intentional, but because that
is the nature of the information available and the way in which
long-standing procedures for risk assessment have been done.
I think Congress needs to give EPA a more realistic basis,
mission statement, and organizational framework. The stovepipe
issues that you raised earlier really hinder its ability to do
comparative risks or even to want to do them.
Senator Smith. In moving from that to you, Mr. Davies, you
said that you felt that you didn't see how we could get there
with the stovepipe approach.
Briefly, how would you reorganize those laws? I mean right
now you do have a series of specific environmental laws, i.e.,
stovepipes. How would you suggest that we reorganize in the way
of blending these together, if necessary, or what are you
suggesting we do, just briefly?
Mr. Davies. I am suggesting that one goes to a single
integrated environmental statute. I had occasion 12 years ago
to draft such a statute. I would be happy to make it available
to the committee.
Senator Smith. The challenge is accepted. We would like to
see it.
In that individual statute you are saying the various
components of the disciplines, clean air, clean water,
Superfund, and so forth, would be all within that statute and
the prioritization would be whose responsibility?
Mr. Davies. Well, ultimately, the Administrator's, but the
task would be considerably simplified because you would not
have individual programs, focused on individual media or
individual pollutants, defending their turf in the same way
that you do now.
So, it would be easier to set priorities across the entire
range of environmental problems.
Senator Smith. Thank you. We would like to see that.
Ms. Hartnett, as you know, I am very familiar with the
leadership in New Hampshire on many of these proposals,
especially in risk assessment.
In your view, does Federal law help you or hinder you to do
a better job at the State and local level in comparative risk
assessment?
Ms. Hartnett. I will answer actually by referencing a
cartoon that is in the record. It is a very good question. The
cartoon shows a figure called ``science'' rubbing a bottle. The
genie comes up and the question is ``Are you a good genie or an
evil genie?'' The answer is ``yes.'' I would say the same thing
about the role of the Federal Government. Yes. Seriously, there
has been a lot of work done, particularly through work in air
resources to relate the nature of the specific chemicals that
are regulated to the underlying causes.
In waste, probably less progress.
In water, a mixed record, I would say, in New Hampshire.
Senator Smith. You reminded me of one of Yogi Berra's
infamous remarks when he said, ``When you come to a fork in the
road, take it.''
That is kind of similar to that.
Let me ask you, Dr. Anderson, essentially the same
question. As currently organized--as the EPA is currently
organized, is it capable of meeting the challenges that you
have identified in conducting appropriate risk assessment?
Ms. Anderson. I think it is. But there are many other
elements to be considered. I think it is not necessarily the
organizational structure that is the difficulty.
I have mentioned the complexity of the challenge, and it is
an enormous challenge. Resources are always an element, and I
have mentioned that as well.
I think the biggest difficulty is to grasp the significance
of the advances in the sciences that we are dealing with and
find a way to realistically employ them. If there is a
commitment to do so, I believe it can be done. But I think
there needs to be a very clear prescription for accomplishing
this.
I don't necessarily think that the organization of EPA is
the impediment to this. I think there are clearly many other
barriers because we are not getting there fast enough.
I think the concepts that I presented in my written
testimony for trying to correct what Dr. Lippman said earlier,
that we have intentionally biased risk assessment to protect
public health, this was necessary in the early years because
risk assessment approaches would not have been accepted at all
had there not been a provision for replacing uncertainty with
public health protective assumptions. We were moving from the
zero risk tolerance policy to an acceptance policy. So, we had
to be sure we didn't underestimate the magnitude of public
health.
Having said that, we cannot continue to employ those same
approaches for serious regulatory decisionmaking. We said this
in 1976. This isn't something new. Therefore, the emphasis
needs to be on an iterative process to refine risk assessments,
and a commitment to following this process.
Now, whether structure makes this happen or resources make
this happen or legislation makes this happen, it is probably
some element of all of these. But I think the focus needs to be
on the goal and then the way to get there, the implementation
process, can be more carefully inspected.
Senator Smith. That is a good answer.
Finally, Mr. Pompili, you were talking about support and
technical assistance from the Federal Government and how it
would be helpful to the States. What other role, other than
funding, would be appropriate for the Federal Government to
assist in your risk-based decisionmaking?
Mr. Pompili. Right now we are in a situation where we are
starting to work with Region 5. We are taking a look at ozone
attainment in central Ohio. Now we are using Region 5 a little
bit for some technical advice as we are going through this
process.
The other thing that comes through, and it is kind of scary
but I have been involved with this from time to time, the data
that is out there comes across as factual on a local level.
Basically, with all this information out there, and it is up on
the Web sites and everywhere else, everybody thinks because it
is from the EPA, they think this information is always correct.
If we can get that information to be correct and be
accurate to what really is going on, it would be very
beneficial. So, I talk about having technical information from
the regions to help out and second, also having accurate
information over the Web that is available on a local level
would be a lot more beneficial to our decisionmaking process.
We know from local experiences that in a great many of
decisionmaking situations the abundance of information causes
us more trouble on the local level than it helps. Information
is put out there, as the information is out there, there should
be an accurate way to distribute data that is useful.
Senator Smith. Thank you so much for the answers. You have
been a very good panel, very interesting. I appreciate all of
you coming here. I know many of you came a long distance. Thank
you very much for coming and putting up with the little
interruption we had to have here because of the 2-hour rule.
I will dismiss this panel and call up Panel III. Panel III
is Mr. Lee Hughes, the vice president for Corporate
Environmental Control of the Bayer Corporation; Mr. Robert
Brenner, Principal Deputy Assistant Administrator for Air and
Radiation, Environmental Protection Agency; Dr. Philip Hopke,
chair of the Residual Risk Subcommittee, Science Advisory
Board; and Ms. Felice Stadler, national policy coordinator of
the Clean the Rain Campaign, the National Wildlife Federation.
Welcome to all of you. Since you have one lady, I will
start on the right side and move down the panel to the left.
Your complete statements will be made a part of the record.
Please feel free to summarize in 4 or 5 minutes if you can.
We will start with you, Ms. Stadler.
STATEMENT OF FELICE STADLER, NATIONAL POLICY COORDINATOR, CLEAN
THE RAIN CAMPAIGN, NATIONAL WILDLIFE FEDERATION
Ms. Stadler. My name is Felice Stadler. I coordinate the
National Wildlife Federation's National Clean the Rain
Campaign. The campaign seeks to raise public awareness about
how toxic air pollution contaminates our lakes and streams and
advocate for national and local policies to phaseout the
emissions of mercury and other persistent biocumulate toxics,
PBTs.
While we recognize that EPA needs to refine its methodology
for performing residual risk assessments, we firmly believe
that the program must be preserved and adequate resources be
provided to allow the Agency to do the critical assessments
needed to protect humans and wildlife from actual harm.
As you are aware, Congress amended the Clean Air Act in
1990 to establish a more effective program to reduce toxic air
pollution. Congress required major sources that emit any of 188
listed toxic air pollutants to make performance standards based
on the best industry practices to minimize toxic releases.
Have reductions achieved to date solved the air toxics
problem in communities and ecosystems throughout the United
States? Certainly not. People and wildlife continue to be
exposed to toxic air pollution, which harms their well being.
For this reason it is vitally important that EPA move to
the next phase of its national air toxic strategy, the Residual
Risk Program.
Now, I will mention three reasons for why we need to do
this. First, without residual risk, EPA will not be able to
address the harm posed by the most toxic air pollutants, PBTs
like mercury and dioxins. PBTs are harmful at extremely low
levels and uniquely harmful to people and wildlife because they
become increasingly toxic as they move up the food chain.
For example, mercury is one million times more toxic in
fish than in surrounding water. So, when we eat fish we are
consuming concentrated mercury. Those most vulnerable to the
effects of PBTs include unborn children, women, low-income
communities, and communities of color.
EPA is not required to address the full extent of the harm
posed by the most toxic compounds through technology standards.
Therefore, the residual risk program is critical to ensure
unique risks are appropriately addressed.
Second, EPA's technology standards do not take into account
the cumulative risk that occurs when industrial sources are
concentrated in one area. For example, in Memphis, TN, you can
see sources of toxic air pollution in every direction: A
petroleum fueling station, a six-lane highway, a refinery, a
lead smelter and a factory.
Less than a block away from these sources there is low-
income housing and a playground. Unfortunately, this picture is
not unique. Risk-based programs enable EPA to evaluate these
real life scenarios that are all too common for countless
citizens.
Third, Congress and EPA never intended the technology-based
program to address entirely all toxic emissions from all of its
sources. Technology-based standards provide the best industry
can offer at the time they are imposed. But this does not
translate into being the most stringent or comprehensive
approach.
In fact, when EPA issued the proposed Portland Cement Kiln
rule 2 years ago, EPA announced it would evaluate the need to
make the standard more stringent to address mercury emissions
as part of the residual risk phase.
Without this program, this category of sources and others
like it would likely never be adequately regulated under the
Clean Air Act.
In conclusion, I want to raise the issue of uncertainties
related to the residual risk program. Every risk assessment
must contend with uncertainties: Who is exposed? How much they
are exposed to? The health effects of pollutants.
Requiring every uncertainty to be addressed before taking
action would effectively mean no action will be taken. EPA is
refining its tools to carry out the residual risk program. It
should be given the opportunity to go forward and implement
that program. But policy paralysis will be the result if EPA is
required to address every uncertainty before acting.
Finally, I would like to close with two recommendations to
improve how we regulate sources of air toxics. First, the risks
to people and wildlife from several PBTs are well established.
Any release of these pollutants causes harm. For that reason
and international agreements, the United States has committed
to virtual elimination of these pollutants.
To properly address the unique risks posed by PBTs, EPA may
not engage in complicated risk analysis. Instead, it simply
needs to set a schedule for phasing out the emissions of these
chemicals from all sources and then apply progressively lower
emissions standards to meet that goal.
Second, rather than merely relying on pollution controls to
solve the Nation's air toxics problem, we urge Congress and the
Agency to look at solutions that encompass pollution
prevention. This applies to both the technology-based program
and the residual risk program.
EPA has the tendency to assume that all pollution is
unavoidable and that bolting on technology will solve the
problem. Instead, it is time for EPA to begin to assess what
pollution could be avoided altogether and develop policies that
reflect a commitment to more sustainable and less toxic
solutions.
Thank you for the opportunity.
Senator Smith. Thank you.
Before I introduce Dr. Hopke, I want to apologize to the
witnesses. I have to leave. I do have another appointment.
Senator Inhofe is going to finish chairing the hearing.
Dr. Hopke, welcome.
STATEMENT OF PHILIP HOPKE, CHAIR, RESIDUAL RISK SUBCOMMITTEE,
SCIENCE ADVISORY BOARD
Mr. Hopke. Thank you. Mr. Chairman and members of the
committee, my name is Dr. Philip Hopke. I am here to discuss
with you the views of the Residual Risk Subcommittee on the
residual risk methodology as described in EPA's report to
Congress, particularly as applied to the secondary lead smelter
source category.
I chaired this subcommittee of the EPA's Science Advisory
Board's Executive Committee. My testimony will try to reflect
the consensus view of the subcommittee with some added input
from the Science Advisory Board's Executive Committee, although
I am speaking for myself.
In early March the subcommittee conducted a peer-review of
an Agency draft case study of the residual risk assessment
methodology applied to secondary lead smelter source category.
We understand that the Agency plans another iteration
including additional data collection and analysis before these
results are considered for use in a regulatory context.
Review of the seven-volume set of materials focused on
eight specific questions that are addressed in detail in the
SAB report that has been submitted to you.
In short, the subcommittee concludes the Agency developed a
useful, self-described work in progress. The methodology used
in this interim work product as far as it currently goes is
consistent with the methodology described in the report to
Congress. Further, many of the assumptions used are consistent
with current methods and practice.
The case study provides an example of how the approach
presented in the report might be implemented. However, it also
raises a number of concerns we provided in the report on this
document. The major concerns will be highlighted here.
Because the subcommittee has not seen the full residual
risk assessment and thus we are unable to comment on the
complete process, a number of important concerns were
identified that should be addressed.
Specifically, this interim analysis does not include the
following important elements: A full ecosystem risk assessment,
a health risk assessment that includes population risks, a full
analysis of uncertainty and variability, a computer model for
assessing multi-media transport and fate that has been
adequately evaluated, a clear description of the process and
how the assessments will be linked to the eventual risk
management decisions.
I would like to highlight a couple of these problems to
illustrate a larger concern that we would like to bring to your
attention.
The current analysis for secondary lead smelter was done
using the multimedia transport and fate model that was
originally developed as part of the analysis reported in the
mercury report to Congress. However, it was never fully peer-
reviewed for its use in mercury, and it was then modified for
use with lead without review of assumptions and coefficients.
EPA has been developing a new multimedia exposure model,
the total risk integrated methodology that had undergone an
initial review by the SAB. It was quite encouraging.
However, it now appears that completion of this model and
its use in risk assessment has been slowed so that it may not
be available in the near term. This delay produces serious
doubts in any of the assessments that have to be based on a
temporary model that has not been subjected to careful external
scrutiny.
Another of the most serious problems was the inability to
utilize the available data to test the modeling results. In the
secondary lead smelter case, fugitive emissions were found to
produce most of the risk.
In several of the cases, results presented in the draft
report were implausible in that the predicted concentrations
would have produced immediately observable results on the
effected human and ecological populations.
In the vicinity of most of these sources, sampling was
conducted to test compliance with the national ambient air
quality standard for lead and total suspended particulate. Such
measurements could be used to test the concentrations at the
boundaries of these facilities.
However, the risk analysis could not utilize these ambient
monitoring data that are available in the air's data base
because of lack of resources to recover and then organize them.
An important policy question arises as to how good such
residual risk assessments need to be.
It is our understanding that when the form of control
specified in title III was being considered by Congress a
decade ago, the expectations for the level of these residual
risk analysis were quite low.
The scientific basis of risk assessment has grown
considerably over the past years and thus the level of
expectation from the scientific community such as those of us
who have served on this SAB subcommittee has risen
considerably.
Thus, the subcommittee has expressed its concerns regarding
future assessments. Accordingly, I wish to use this opportunity
to express our concerns regarding the level of analysis that
can and should be done to assess residual risk as part of the
control of hazardous air pollutant emissions.
The subcommittee believes it is possible to provide more
quantitative and useful human health and ecological risk
assessments than is currently envisioned for a reasonable
investment of additional resources for data collection and some
additional outside expertise as needed.
The resulting assessments will be much more credible to
both the regulated community and those potentially effected.
I would like to express my gratitude to the members of the
committee for inviting me and giving me the opportunity to
deliver the SAB Residual Risk Committee's review message.
I look forward to your questions.
Senator Inhofe [assuming the chair.] Thank you, Dr. Hopke.
Mr. Brenner.
STATEMENT OF ROBERT BRENNER, PRINCIPAL DEPUTY ASSISTANT
ADMINISTRATOR FOR AIR AND RADIATION, ENVIRONMENTAL PROTECTION
AGENCY
Mr. Brenner. Good afternoon, Senator Inhofe. I welcome the
opportunity today to discuss the Residual Risk Program, which
is one component of the Clean Air Act strategy for protecting
the public from toxic air pollution.
In the landmark Clean Air Amendments of 1990, Congress
called for a two-phased approach to reducing toxic air
emissions from major industrial sources.
First, EPA is to issue technology-based standards on an
industry-by-industry basis to ensure that all plants are well
controlled.
In the second phase, EPA must assess the remaining risks
from those industries and, if necessary to protect health and
the environment, set residual risk standards requiring further
reductions in toxic emissions.
A decade later EPA continues to believe that it makes sense
to evaluate whether MACT standards provide the public with
adequate health and environmental protection and to take action
if they do not.
EPA regularly hears from citizens concerned about whether
toxics are endangering them. These citizens include minority
and low-income residents who are often disproportionately
represented in neighborhoods near industrial sites.
Although the job will not be easy, EPA, with the aid of the
scientific community, including the National Academy of
Sciences, has developed risk assessment methodologies and risk
management procedures that can help to support reasoned
decisions on whether to require further emission reductions
based on the available scientific information and consideration
of uncertainties.
When Congress overhauled the Clean Air Act in 1990, it was
well established that the public is exposed to toxic air
pollutants such as lead, benzene, dioxin, mercury and chromium.
It was known that air toxics can cause serious health effects
such as cancer, neurological damage, miscarriages, birth
defects or lung damage.
In response, Congress rewrote the ineffective air toxic
provisions of the 1970 act and mandated a comprehensive
strategy to toxic air pollution, including the two-phased
approach for major industrial sources that I mentioned earlier.
I am happy to report that the first phase of the program
which requires dirtier facilities to achieve a level of
performance already being achieved by cleaner facilities of the
same type is proving very successful.
Maximum Achievable Control Technology standards issued to
date will reduce annual emissions of air toxics by 1.5 million
tons, many times the reductions achieved by standards issued
during the 1970 to 1990 period.
As we work to complete those MACT standards, we are in
parallel beginning to implement the second phase, the residual
risk program.
As Congress directed, we will start with the science. We
will conduct risk assessments based on available information,
and credible and relevant scientific studies conducted around
the world by universities, governments, industry and others.
Considering all the available health information, the law
then calls for EPA to make an informed decision whether a
source category needs to make further reductions to bring toxic
emissions to a safe level.
In the time remaining I would like to talk about some of
the issues that are being raised today. A Science Advisory
Board panel has reviewed an incomplete EPA case study that
illustrates methodologies we will use for screening analysis in
the residual risk program.
We asked SAB to review this incomplete case study precisely
because we wanted external reviewers to help us improve our
methodologies before we finished the study. We are doing just
that, based on the very good technical comments that we
received.
I would like to submit for the record EPA's response to the
SAB. The SAB expressed general concern about data gaps. In
response, we are working, for example, to improve the national
toxic inventory, a repository of air toxics emissions data from
States.
We are working with States and cities to expand monitoring
of ambient air toxics levels. We are developing a new, better
multi-pathway methodology called TRIM, the Total Risk
Integrated Methodology, which has received two very favorable
reviews from the SAB.
We are also conducting modeling on a national and local
scale to improve information on the level of air toxics that
people are exposed to. We disagree with statements by some
individuals that data gaps make it impossible for EPA to carry
out the statute.
The law does not require residual risk decisions to be free
of uncertainty. For many source categories uncertainties may
preclude a precise risk estimate. Even so, the body of health
information often may support a reasoned judgment whether or
not public health is protected with an ample margin of safety.
In light of current uncertainties, some may suggest that
EPA wait for more complete information before attempting to
assess and address any risks from air toxics remaining after
MACT.
The flaw in this approach is that in some cases individuals
may continue to be exposed to an unsafe level of toxics near
industrial facilities while we fail to act based on information
that is available now.
In the field of environmental protection as in much of
life, there are few decisions for which we would not like to
have more information. The reality is that to avoid paralysis,
we must make reasoned choices based on the information we have.
If there is not sufficient evidence of a threat, however,
EPA will not issue a residual risk standard. If toxic emissions
are unsafe based on the framework provided by Congress, EPA
will take protective action.
Thank you, Senator Inhofe, for the opportunity to testify
here today.
Senator Inhofe. Thank you, Mr. Brenner.
Mr. Hughes.
STATEMENT OF LEE HUGHES, VICE PRESIDENT OF CORPORATE
ENVIRONMENTAL CONTROL, BAYER CORPORATION
Mr. Hughes. Good afternoon, Senator Inhofe. My name is Lee
Hughes and I am vice president of Corporate Environmental
Control for Bayer Corporation. I am responsible for the
environmental matters of Bayer's U.S. operations. This includes
compliance with the Clean Air Act.
I am here today representing the American Chemistry
Council.
Senator Inhofe. Let me ask, for a moment here, on my time,
would you elaborate a little more on what the Bayer Corporation
does for the record.
Mr. Hughes. The Bayer Corporation is an operation in the
United States, which is owned by our parent out of West
Germany. We are a $10 billion operation with 35 facilities
throughout the United States employing roughly 24,000 employees
making agricultural chemicals, base chemicals, pharmaceuticals,
diagnostics equipment, and a pretty multi-service operation.
Senator Inhofe. Thank you. Welcome.
Mr. Hughes. I am here today representing the American
Chemistry Council. The Council represents the leading companies
engaged in the business of chemistry. The chemical industry
supported the 1990 Clean Air Act Amendments. For over a decade
we have worked with EPA in the development of programs that
continuously make people's lives better, healthier and safer.
Our industry supports the Clean Air Act's approach for
regulating air toxics which first requires the application of
technology-based MACT controls and then it looks at any
unacceptable residual risks.
EPA has estimated that our industry has achieved a 90-
percent emission reduction due to our MACT performance. The
residual risk effort can build on these reductions. If residual
risk regulations are needed for our industry, they will be due
in 2003. This means that important decisions about this program
are being made now.
We believe the following key principles will ensure a
successful residual risk program. We must first prioritize real
and scientifically-validated risks. Second, we must use the
flexibility provided in the Act to reduce risks in innovative
and effective ways. Third, we must use high quality and peer-
reviewed models and data.
These principles are detailed in our written statement.
However, we are aware of several barriers that could hinder our
efforts to further reduce risks.
EPA's Science Advisory Board has highlighted many of them.
These barriers need your attention. The first barrier is
outdated health information. The health benchmarks used for
residual risk must reflect the best scientific information
available. The IRIS data base, the EPA's primary source of
health data on hundreds of chemicals is out of date and of
varying quality. The Commission on Risk Assessment and the
Science Advisory Board agree IRIS's limitations are certain to
hinder our ability to identify and then reduce risks.
What can be done? EPA is trying to increase the pace of
IRIS reviews and open the process to stakeholders. This process
both needs to be supported and expedited so that new
information can be used for residual risk assessments.
Staff and resources for IRIS must be increased. Our
association members will spend more than $600 million on health
and environmental research related to chemical use. The
residual risk regulations, however, will be due before we and
EPA can complete our work. That is why Congress must ensure
that EPA is open to and uses new scientific information in the
residual risk regulations.
The next barrier is non-peer review tools. EPA must subject
the key tools used in this area to a balanced scientific
review. To ensure they are really reducing risks, we must base
risk assessments on high quality peer-reviewed science.
Another barrier is outdated emissions and site information.
The most recent EPA data on our industry does not reflect
significant reductions we have already achieved. To correctly
identify risks we need more current information about emissions
and facility characteristics. We are voluntarily providing EPA
with better information, but the task before both EPA and us is
immense.
Finally, the statutory clock is running. There will be a
significant challenge to address these limitations within the
Act's current deadlines. Adding to this challenge, the Act
requires compliance with the risk standards within 90 days of
promulgation. This will be a near impossibility if sources must
design, procure, and install new technology or change chemical
processes to incorporate pollution prevention instead of end-
of-pipe controls.
It won't be long before a deadline is missed. Congress
should not let this program be carried out by the courts in
closed-door settlement discussions.
Again, to achieve success in reducing residual risks we
must update health benchmarks and use the most current
scientific information. We must peer-review all key tools,
obtain better emissions and site information, and continue this
important oversight of EPA's ability to meet the requirements
of the Act.
I reiterate our industry's commitment to work with you, EPA
and all stakeholders to achieve success.
Thank you for hearing my testimony today. I would be happy
to answer any questions.
Senator Inhofe. Thank you, Mr. Hughes.
Mr. Hughes, the thing you brought up last is the thing that
concerns me more than anything else. The EPA began the Residual
Risk Program by first looking at the lead smelter industry.
It is my understanding that one of the reasons for that was
that it is less complicated and there is more data. In other
words, you would be able to expedite that a little quicker than
some of the rest of the industrial sectors. Is that accurate?
Mr. Brenner. Well, it happened to be an industry where we
had some data that we could begin to look at.
Senator Inhofe. A running start.
Mr. Brenner. I am not sure it is the one that had the most
data available to us.
Senator Inhofe. All right. On the other industrial sectors,
have you started those and if so, what is the timeline there?
Mr. Brenner. We have begun looking at some of the other
industrial sectors, yes. You have heard we have begun working
with the chemical industry to begin looking at their sources.
We have begun looking at coke ovens. The way the act works, the
first of these analyses is due to be done at the end of next
year.
So, we are trying to conduct a series of screening
assessments to see whether additional controls might----
Senator Inhofe. That is the 2002 deadline, the first one?
Mr. Brenner. I think the first one is actually following
2001 and then there is more following 2002.
Senator Inhofe. Well, you know, I think it is important to
talk about this problem today. What I didn't want to happen is
to wake up 2 years from now and find out, as Mr. Hughes was
suggesting that we are not getting it done in compliance with
the laws that we have to live by right now and then end up
having the courts getting involved in it.
Even though this has to be very short because of what
happened on the floor today, and I will make this real quick,
but I am concerned about what choices we have right now.
In the second panel, Dr. Lippman said that we should
continue the MACT Program but put off the Residual Risk Program
until we can conduct better risk assessments. So, first of all,
let me see what reaction to Dr. Lippman's statement you might
have at the table.
Mr. Hopke. I think we are in a position to conduct
reasonable residual risk assessments for the purpose of seeing
whether any of these post-MACT facilities produce an
unreasonable and unacceptable risk.
Again, the precision with which we can do that may not be
the best in terms of setting standards or similar kinds of
things, but in terms of trying to identify whether there might
be any real problems to real people living in the vicinity, I
think we have the basic tools or could have the basic tools in
place and time with a bit more focus by the Agency.
I mean, they have been working on TRIM for a while. It was
our understanding that it had been slowed down to some extent.
We would like to see that really get rolled out and be ready to
run.
When you don't even have enough resources dedicated that
you cannot poll your own data bases to do reality checks on
your models, it seems like something is wrong. So, we think
that it is a process with some reasonable fixes that could
provide the kinds of information that are going to be needed to
make the decisions that are necessary.
Senator Inhofe. Well, Mr. Brenner said that it was
incomplete when it was given to the Science Advisory Board.
Mr. Hopke. We understood that. It was a draft.
Senator Inhofe. Why did you decide to do that instead of
trying to get it as complete as possible before giving it? What
constraints were you under?
Mr. Brenner. The reason we did that was we wanted the Board
to have an opportunity to look at the methodology before we
completed the analysis. That way, if we needed to change the
methodology, make adjustments to it, we could do that before we
made a final decision on these lead smelters.
Meanwhile, in parallel, we have been collecting additional
data to make sure that we have more robust data before we make
that final decision.
So, it was an effort to consult with the Science Advisory
Board as early as possible in the process. It has proved to be
very valuable.
Senator Inhofe. So, now you have had that evaluation so you
have a better indication of where you can go from here. What is
your timing now?
Mr. Brenner. Our timing now is to try to continue to
develop some of the methodologies that will be used, as you
heard. This TRIM model, for example, the Total Risk Integrated
Methodology, will be helpful to us in making a final decision
on lead smelters.
We are also trying to work to collect additional data,
talking to the States, talking to the industry, and talking to
some of the health departments in areas where these smelters
are located. We want to pull all of that information together
and sometime next year be able to make a decision as to whether
we should proceed further in the risk assessment process.
We always have the opportunity partway through to decide
well, we have looked at the source category, and based on what
we found with our initial assessment, there is not enough
concern about risks to proceed.
We could decide that we don't need to take additional
action in that area and we can turn to other source categories
or we may find there is still cause for concern and then we
will have to use more sophisticated methodology and data to
finally make a decision.
We are hoping to use this screening approach so that in
many instances we won't have to spend a lot of time with the
industry. Our initial screen will tell us that there is not a
significant risk there and we can return to the areas where our
priority should be greater because there is greater cause for
concern.
Senator Inhofe. When Mr. Hughes expressed a concern that
this end up in the courts, do you all share that concern or
what thoughts do you have on that?
Ms. Stadler. I would like to jump back in and respond to
the first question and then I can address that as well. We are
definitely not done with the MACT program, with the technology-
based part of the Clean Air Act.
We would encourage the Agency to continue to invest
resources to finish that program and to finish it effectively.
There are still a number of key sources that have not been
effectively regulated.
At the same time we want to make sure that the residual
risk part of the program does proceed and that we don't wait to
make sure that all these issues are resolved.
In particular, we would like to see EPA prioritize and
start looking at some of the rules that they knew initially
were probably not stringent enough. I gave the example of the
Portland Cement Kiln Rule.
In the Federal Register notice, EPA did acknowledge that it
likely is not an effective rule because it was not regulating
some key pollutants. We would like to see EPA go back to that.
In terms of getting things caught up in the courts, we
definitely agree, we would like to see this process proceed
swiftly, but also not jeopardize quality. But at the same time
we don't want to see it get hung up in the courts because then
things just basically cease to move forward. That would not be
in the best interests.
Senator Inhofe. Are there any other thoughts?
Mr. Hopke. I don't see that getting it into the courts will
be a productive way of protecting public health.
Senator Inhofe. The whole idea is to avoid that.
Mr. Hopke. Yes.
Mr. Hughes. I guess one comment which maybe goes to the
source of our concern, is seen by just looking at the
comparison between that which was done on the lead smelter
issue dealing with some 20 facilities and probably less
hazardous air pollutants than we are having to deal with in the
particular segment of our industry we are currently
approaching, which will include over 250 facilities, deal with
100-some chemicals in a lot of different locations.
You know, it is a concern that we haven't, let us say,
underestimated the task involved and the complexity involved.
When moving from somewhat of a smaller look at the risk
assessment approach and now, how are those same principles
applied to the larger one?
We will just need to keep watching that, along with the
timeframes, to make sure we don't get ourselves in a situation.
Senator Inhofe. When I first walked in I heard Senator
Smith--I wasn't sure what context it was in or what question
was asked. He was talking about appropriating more money.
Other than pouring more money on this, what role does each
one of you see Congress playing in this to try to get this
done? Let me start with you, Ms. Stadler.
Ms. Stadler. Well, I think playing an oversight role is
always important if it is a constructive role. I think that
obviously we need to make sure that the resources are
available.
But at the same time I think Congress should support what
the Agency is doing to implement this program as opposed to
using the oversight process to stall progress.
Congress can make sure that things are going on the right
track, that you get feedback from the Agency in terms of
whether their resources are adequate, but again, not to use it
to basically tie the Agency's hands or to become too
prescriptive in terms of how to move the Agency forward.
Mr. Hopke. I think one of the things would be to clarify
just what level of precision and uncertainty in the risk
assessment is going to be acceptable.
Again, I think there has been a change in the view of what
these residual risk assessments would have entailed when the
law was put in place in 1990 relative to then what Congress had
asked for from the NAS panel that produced ``Science and
Judgment'' and now a higher level of expectation in terms of
the quality of the output product.
I think some clarification as to how good is good enough to
make decisions is one of the things that I think we might be
grappling with here.
Mr. Brenner. Senator Inhofe, I believe there are two areas
where we could work closely with the Congress on this set of
residual risk issues. The first is resources, not to throw
money at it, but just the fact that we heard from the earlier
panels that to collect data on these chemicals and to collect
data on the emissions from the sources of these chemicals is a
resource intensive task. Unfortunately, given budget
constraints, we have not been able to provide the resources
that had been requested in previous years.
Hopefully, there will be some opportunities to work
together to address that in the future. Then the second area is
on this very difficult decision. If we do find source
categories that pose significant risk, then there is a decision
as to what level of control might be appropriate, what
constitutes what is called in the statute ``an ample margin of
safety?''
That involves considering risk, the potential for effects
on sensitive individuals. It also calls for considering costs
and technology availability. That is the sort of thing, where I
think as we come to the first few of these categories where
such a decision may be necessary, we would probably want to
work with you and your staff to talk through these issues and
make sure we both understand the set of concerns we would be
grappling with.
Mr. Hughes. I think I will just reiterate on the issue of
resources. Without resources the program can't achieve
especially the pace that it is expected to achieve. So,
supplying resources to make sure that can happen, there you are
talking about financial resources to go to the Agency to make
sure the programs are funded to where they need to collect data
and address those issues from that perspective.
I also think that as we move through the process, I don't
have one specific identified at the moment, but there may be
cases where we identify, maybe, some problems or some things
that need to get fixed.
If there is a way that we can approach something from a
more holistic standpoint but we end up getting blocked by a
piece of legislation. If there is a way that all the
stakeholders could come to agreement that it is a better
approach at doing that, support from Congress would be
necessary to be able to correct some of those inherent things.
As I said, I don't know or have one specifically at the
moment, but as we move through this we typically run into some
things like that.
Senator Inhofe. What about deadlines? Primarily, Mr. Hopke
and Mr. Brenner, do we need more time?
Mr. Hopke. Well, at the level of resources currently being
allocated, I cannot imagine how they are going to meet the
deadlines.
Mr. Brenner. I think it is too soon to say that we are
going to need more time. We are conducting these screening
analyses. We are working on collecting the additional data.
I still believe that by working with the industry groups,
working with the States, using data that other governments have
collected the California EPA, that we can move through the
initial screening assessments rather rapidly and then see how
many industry categories we need to focus on.
I think until we have gone through those early stages to
see how this screening process works, we don't know yet that we
will need more time.
Senator Inhofe. Here is what I would like to do and one
reason we wanted to have this: To avoid a train wreck, now is
the time to be addressing this thing.
What I would like to ask you to do, Mr. Brenner--well any
of you while you are working your way through this--if it
appears that deadlines have to be changed, that, you know,
changes have to be made, that we find out about it early enough
that we can do that before we run out of time.
That is one of the major concerns that we have on our side
of the table. So, if you can keep us informed as time goes by
as to the progress you are making and how much more time you
might need, if you do need it, we need to know.
Mr. Brenner. We will certainly do that and then we can
assess, sometimes as we get closer to the deadlines whether
more time is needed.
Senator Inhofe. All right. We are right now at the time
that we have to quit. I think you know what happened on the
floor today. There will be questions that we will send you to
be answered for the record.
But right now, if there is any last statement you want to
make, the four of you, if you make it brief, this is your
chance.
Thank you very much for coming. We look forward to
continuing to work with you as we near these deadlines we are
talking about.
Thank you.
[Whereupon, at 12:30 p.m., the committee was adjourned, to
reconvene at the call of the chair.]
[Additional statements submitted for the record follow:]
Statement of Hon. Bob Smith, U.S. Senator from the State of
New Hampshire
Good morning. I want to welcome everyone to today's hearing on the
use of Comparative Risk Assessment in setting environmental priorities.
We will also hear testimony on the Science Advisory Board's report on
EPA's case study analysis of residual risk.
I think the excellent materials that we received for today's
hearing show that there's a real interest in using the comparative risk
assessment process to prioritize resources. I am particularly pleased
that Ms. Kate Hartnett, the executive director of the New Hampshire
Risk Project, is here today to talk about New Hampshire's experience
with comparative risk. Her testimony demonstrates the continued passion
and innovative spirit that states and local governments are bringing to
environmental protection.
This is the third in a series of general oversight hearings
conducted by the full committee. Our first oversight hearing looked at
the EPA's proposed budget for fiscal year 2001. Our second oversight
hearing focused on State successes and the need for a new partnership
between the States and the Federal Government. We learned about
programs that work, and those that don't.
Today's hearing takes us to the next level--beginning the process
of identifying the tools that will improve our environmental programs.
Comparative risk assessment is one of those tools. We all recognize
that there aren't enough resources available to address every
environmental threat. The Federal Government, States, local
communities, the private sector, and even environmental organizations
all have to target their limited resources on the environmental
problems that present the greatest threat to human health and the
environment. Our focus, therefore, is, and should be, on getting the
biggest bang for the limited bucks.
Comparative risk is the tool that enables us to prioritize the
risks to human health and the environment and target our limited
resources on the greatest risks. It provides the structure for
decisionmakers to: (1) identify environmental hazards; (2) determine
whether there are risks posed to humans or the environment; and (3)
characterize and rank those risks. Risk managers can then use that
analysis to achieve greater environmental benefits.
Today, we will hear how EPA is using comparative risk to focus on
the right problems and strategies; and to what extent this approach has
led to the development of a results-oriented Strategic Plan.
We will also hear how many states and local governments are already
using comparative risk assessments a public and open process that
allows cooperation, instead of confrontation, and encourages dialog,
instead of mandates. States are setting priorities, developing
partnerships, and achieving real results by using comparative risk as a
management tool. They are using good science to maximize environmental
benefits with limited resources. I believe we should encourage and
promote these successful programs.
I look forward to hearing from the witnesses this morning.
__________
Statement of Hon. Max Baucus, U.S. Senator from the State of Montana
I would like to begin by thanking our committee Chairman, Senator
Smith, for holding this hearing. The issues of comparative risk
assessment and residual risk analysis are not only important, but
timely.
comparative risk assessment
I believe that it is important for this committee to continue to
examine tools for improving the ways in which we protect public health
and the environment.
We need to always look for new approaches to addressing lingering
or emerging environmental problems. We must determine which of these
tools will give us the results, and the efficiencies, that we need.
And at the same time, we must set environmental priorities more
effectively than we have in the past so that our efforts, and the money
that is available, will address the most pressing problems.
I believe that risk-based tools--such as comparative risk
assessment--have much to offer in this regard. Because of this, I have
long been a strong supporter of the use of risk assessment as an
environmental policy tool.
For example, I worked hard with Senator John Chafee and other
members of this committee to find an appropriate role for risk
assessment when we amended the Safe Drinking Water Act in 1996. I am
proud of what we came up with. I think we significantly improved that
law.
At the same time, however, I have also long believed that we need
to proceed carefully and thoughtfully as we consider using risk-based
tools. We need to clearly understand what each tool can do. And what
each can't. Otherwise, we may end up expecting too much or too little
of them.
For example, while I'm a supporter of risk assessment, I often
think that its most ardent proponents oversell it. They simply gloss
over inherent limitations to risk assessment, such as the gaps in data
or scientific understanding, the absence of important analytical
methods, and the sensitivity of this tool to underlying assumptions.
We need to be honest about risk assessment. We take its strengths--
and weaknesses--fully into account in each and every application of
risk assessment.
Further, it is important to remember that any tool we may decide to
use to assist in decisionmaking is just that, a tool. There are no
``silver bullets'' for decisionmaking.
One of the reasons for this is that, despite when we may hear
sometimes, the ``science'' we must depend on is, and can never be,
complete. That's simply the nature of science.
I recall a speech made by Senator Smith, one he made when he first
became this committee's chairman, in which he said that we can't deny a
problem just because the science is uncertain. I couldn't agree more.
If we waited for scientific certainty, we'd end up deferring action on
every single environmental problem we face.
Furthermore, it is critical to recognize that values such as
fairness, equity and other subjective judgments are essential
components of any environmental decision.
A risk assessment may legitimately find that, for most Americans,
hazardous waste sites pose little risk. But it is equally legitimate,
from the perspective of fairness or equity, to ask whether this means
we should decide not to protect the health of the minority of Americans
who happen to live near these sites.
The bottom line is that, when used carefully and thoughtfully,
tools such as risk assessment can be extremely helpful in informing
environmental policy decisions. But they cannot by themselves make
these decisions.
residual risk
Before I end, I would like to say a few words about the second part
of today's hearing, residual risk. I look forward to hearing from our
last panel about the status of the residual risk program.
As everyone here knows, we're gradually beginning stage two of the
ambitious control program for toxic air pollutants that we started in
1990. The MACT standards are almost all done now and EPA has begun to
look at reducing the risks to public or environmental health that
remain after MACT has been applied.
Some people have questioned whether EPA has the ability or the
resources to regulate to get rid of ``residual risk.'' They suggest
that EPA doesn't have enough data or the right data or the right
models. Some of those criticisms may be partly on the mark, but that
has a lot more to do with funding than ``science.'' Residual risk was a
carefully considered provision of the 1990 Amendments and it was not
adopted lightly. We understood that there would be significant
uncertainties associated with estimating risk.
That's why we required a report to Congress first, with any
necessary regulation to follow. And, that's why EPA has to consider
costs, energy, safety and other relevant factors, before issuing
regulations to reduce residual risk.
I look forward to making this program work and further reducing
toxic air pollution.
Again I would like to thank Senator Smith for holding this hearing.
I hope it provides this committee with an opportunity to learn much
more about EPA's residual risk analysis, as well as comparative risk
assessment and what it has to contribute to improving environmental
decisionmaking.
__________
Statement of Hon. Daniel Patrick Moynihan, U.S. Senator from the State
of New York
Mr. Chairman, fellow members of the committee, I am delighted to be
here for a hearing on risk assessment, a topic on which I held my very
first hearing as chairman of this committee in 1992. I am also deeply
grateful to my friends for their kind words today.
I remember fondly the many significant accomplishments that we have
made together on this committee. In 1980, 1982 and 1990 we wrote
significant legislation to curb acid rain and other air pollution that
has choked our skies, fowled our waters, and endangered our health. We
have come a long way to fix these problems, but we still have more to
do and I hope the committee will continue to focus on air pollution and
pass legislation next year to address these ongoing threats. In 1986,
we passed the landmark Water Resources Development Act (WRDA) which
broke a deadlock that had stalled millions of dollars of civil works
projects critical to State and local communities. One of my proudest
achievements is our work on the Intermodal Surface Transportation
Efficiency Act (ISTEA) of 1991 which has changed the way we view
transportation policy.
I have greatly enjoyed my time serving on this committee since I
was first appointed on February 11, 1977. I began my service on the
committee under the leadership of Senator Jennings Randolf of West
Virginia and served as chairman myself in 1992. More recently the
committee has had a wonderful period of productivity under the sage
guidance of my beloved friend, the late John H. Chafee. Today, Senator
Smith serves as a facilitator who conducts the committee's work in a
fair and open process. I will surely miss this committee, its work, and
the friends with whom I have had the privilege to serve.
The matter before us today is one that we cannot take lightly. The
calculation of risks posed by environmental contaminants and the
subsequent determination of appropriate regulatory controls is a
complex exercise that involves not only the lives of our citizens and
the health of our environment, but the State of our welfare and
economy. It is quite clear that environmental regulations have
prevented millions of deaths EPA has estimated that the Clean Air Act
alone prevents 205,000 cases of premature mortality annually. At the
same time, Resources for the Future estimates that $160 billion is
spent annually in the United States for environmental compliance. This
may not be too much to spend on environmental protection, but it is too
much to spend unwisely.
Comparative risk assessment is an example where science must take
the leading role. Only science can give us the parameters to estimate
the relative risks posed by varying concentrations of toxic substances.
However, good science can only be accomplished with adequate resources
and data. The Science Advisory Board has reported to us that EPA lacks
the resources and data to adequately address some aspects of risk
assessment. We must support EPA's request for more research dollars if
we are to expect EPA to adequately address this issue.
In conclusion, I have always believed that good science makes good
policy, and good policy makes good politics. While factors such as
cost, welfare, and even politics indeed play a role, we must ensure
that environmental decisions can always be justified by scientific
research. I thank the committee for the opportunity to discuss this
issue and, again, I am grateful to my colleagues for their kind words
today and for their valued friendships throughout the years.
__________
Statement of Hon. Frank R. Lautenberg, U.S. Senator from the State of
New Jersey
Thank you, Mr. Chairman, for holding a hearing on this important
topic.
Congress tends to address environmental problems one at a time. The
Clean Air Act, the Clean Water Act, and the Resource Conservation and
Recovery Act are each massive, complex laws, and we rarely take the
time to examine where these laws intersect. Last week, this committee
held a hearing on the Streamlined Environmental Reporting and Pollution
Prevention Act, which I have introduced with Senator Crapo and which,
Mr. Chairman, I hope we can mark up soon. That bill reduces the
administrative burdens associated with the piecemeal nature of
environmental reporting.
This hearing essentially addresses a similar issue. In this
hearing, we will discuss whether our current environmental laws are
focused on the whole forest, or just a few well known trees.
That may sound like an abstract notion, so let me bring it to life.
In Toms River, New Jersey, there has been observed a higher than normal
incidence of certain childhood cancers. It's a terrible situation, and
one that is likely happening undetected across the country. So what's
causing it? How do we prevent it? Was it caused by any of the dozens of
chemicals found in tiny amounts in the water? What about the
radioactive materials released to the air from the nearby nuclear
plant? What about the pollution from the cars on the parkway which
bisects Toms River? What are the greatest environmental risks to this
community?
And these are just the questions science can answer. When we as
policymakers decide how best to prevent environmental risks in this
community and across the country, we face other questions that have no
scientific answer: How do we compare the risk of an elderly person's
premature death to that of a child's asthma attack? How do we compare
risks to our health risk to those of our grandchildren and their
children? How do we compare a human health risk to the extinction of an
animal species? At what point do we decide we know enough about an
emerging risk to take a precautionary approach? There are no scientific
answers to these questions--yet we can't decide how best to allocate
our risk reduction resources without resolving them.
That all being said, I look forward to the thoughts of our expert
witnesses on these challenging issues.
Thank you, Mr. Chairman.
__________
Statement of Hon. Joseph I. Lieberman, U.S. Senator from the
State of Connecticut
As the 106th Congress draws to a close, I would like to take this
opportunity to bid farewell to a good friend and a man I deeply
respect, Senator Frank Lautenberg, who is retiring at the end of this
Congress.
During his 18 years in the Senate, he has admirably served his
constituents in New Jersey but he has also served Americans nationwide.
With his acute understanding of the issues, his principled nature, and
his strong, effective leadership, he has stood firm for families. He
has worked tirelessly to build a strong economy, to better the
education and mentoring of our children, to rebuild the infrastructure,
and ensure equal rights and equal opportunity for all Americans. He
leaves a legacy of legislative success from which the Nation will
benefit long into the future. Today, however, I would like to pay
special tribute to his work to preserve our environment.
In our time together on the Environmental and Public Works
Committee, Senator Lautenberg has achieved great things. One that
stands out is the role he played in renewing and improving the
Superfund program. His insistence that people living near hazardous
waste sites be protected from health risks motivated him to address the
broader threat posed by poisons seeping into the earth.
Senator Lautenberg must also be credited for another noteworthy
achievement: public access to information about toxic chemicals
manufactured, used or transported in our communities or released into
the environment. His leadership was instrumental in the establishment
of the Toxics Release Inventory, which, as part of the Emergency
Planning and Community Right-To-Know Act and the Pollution Prevention
Act, requires a publicly accessible toxic chemical data base to be
developed and maintained by the Environmental Protection Agency (EPA).
In great part, because of Senator Lautenberg's vigilance, Americans now
have access to this valuable source of information that both encourages
companies to better manage their toxic substances and provides citizens
with the data necessary with which to challenge violators.
My colleague's love for the environment did not stop with his work
to clean up the land. It extended to the air we breathe and the
waterways that sustain us. As a longtime advocate for clean air, he led
the fight to include a section in the 1990 Clean Air Act Amendments
that set specific limits on the allowable levels of specific hazardous
air pollutants. This was a significant achievement in Congress' efforts
to improve air quality, since before 1990, EPA had not regulated the
majority of these chemicals. The language Senator Lautenberg drafted
left no uncertainty, and we began to remove these toxins from our
skies.
For Senator Lautenberg, the quality of indoor air was equally as
important. He championed the ban on smoking on domestic airline
flights, an accomplishment that literally allows traveling Americans to
breathe easier every day.
He has likewise been a strong advocate of clean coastal areas for
the safety and enjoyment of our citizens. My friend wrote legislation
to ban ocean dumping of sewage and to clear beach areas of rubbish. He
responded to constituent complaints of syringes littering the beaches
and actively promoted legislation to control medical wastes. And he
worked to stop offshore oil drilling and to prevent oil spills from
polluting the water fronts and endangering wildlife.
Finally, Senator Lautenberg's abiding interest in transportation
has improved the safety and quality of life for Americans coast to
coast. He successfully encouraged states to raise the national drinking
age to 21 and has since sponsored legislation to lower the national
standard over which a driver is presumed drunk to a blood alcohol level
of 0.08. He demonstrated particular leadership in the battle to
authorize and fund a national Intelligent Transportation Systems
program to reduce traffic congestion and speed motorists to their
destinations and successfully sought to block the expanded use of the
larger, triple trailer trucks. This was a special victory, for he felt
passionately that longer, combination vehicles endangered the lives of
others on the road. We must also be grateful for the Senator's longtime
commitment to a passenger rail system and mass transit investment. He
championed the Boston to D.C. high-speed rail which will open as early
as Thanksgiving and sponsored legislation for a major Federal
investment in the development of high-speed rail corridors across the
Nation.
Through these and many other efforts, the Senator from New Jersey
has helped to ensure that Americans live in a cleaner, safer and
healthier environment. I commend him for his significant and lasting
accomplishments and thank him for his dedication and leadership. It has
been an honor to work by his side, and I wish him great happiness in
his future endeavors.
__________
Statement of Dr. Al McGartland, Assistant Administrator, Office of
Policy, Economics, and Innovation, U.S. Environmental Protection Agency
introduction
Good morning, Mr. Chairman and members of the committee. I
appreciate this opportunity to present EPA's views on the value of
comparative risk assessment, and the extent to which we use this tool
to attain the Agency's, and the Nation's, public health and
environmental goals.
EPA's interest in comparative risk dates from 1987, when we
produced a groundbreaking report, Unfinished Business, that assessed
and ranked 31 different environmental programs that we had the legal
responsibility for managing at the time. That report marked the first
time in the Agency's history that we attempted a comprehensive, cross-
media, risk-driven comparison and ranking of environmental risk. Then
in 1990 EPA's Science Advisory Board (SAB) produced Reducing Risk, a
report that examined strategies for reducing major environmental risks,
and recommended improved methodologies for assessing and comparing
risks and risk reduction options in the future.
Since then, comparative risk assessments have become more widely
accepted as an input to the priority-setting process. They have been
conducted by a number of State and local governments, and I am pleased
to see that representatives from cities and states have been invited to
present their perspectives to this committee. For its part, EPA has
made use of this tool in our Agency-wide strategic planning processes,
in our partnerships with state, local, and tribal governments, and in
many specific programs, both regulatory and non-regulatory. There is no
doubt that comparative risk assessment today is helping EPA, other
levels of government, and the business community prioritize risks,
target our respective risk reduction efforts, and thus reap more
environmental benefits for every dollar spent.
At the same time, I want to emphasize that the usefulness of
comparative risk assessment is limited. It is not being used by EPA
today, and most likely never will be used, as a bright-line,
mechanistic way of ordering the Agency's priorities for either
strategy, budgets, or actions. A number of other factors also have to
be considered, and all these relevant factors, including but not
limited to comparative risk assessment, have to be considered when the
Agency sets its priorities.
For example, many Federal environmental laws set timetables and
deadlines for EPA to take specified actions or accomplish specified
goals. EPA has an obligation to carry out the laws, which reflect the
will of an elected Congress and properly reflect considerations beyond
comparative risk.
Another difficult problem arises in any attempt to include human
health and ecological risks in the same ranking. How do you prioritize
the risks associated with pollutant exposures that may cause cancer in
humans, as compared to degraded water quality in the Chesapeake Bay
that may deplete oyster beds? The Science Advisory Board recognized
this problem when they wrote Reducing Risk, and they did not attempt to
include human health and ecological risks in the same ranking.
Community concerns also have to be considered when setting
environmental priorities. If a community believes that action must be
taken to solve what it considers to be a pressing environmental
problem, then EPA has an obligation to respond, even if the problem
does not rank high on a list of comparative risks.
Another consideration in setting priorities is the different roles
that EPA has, depending on the environmental problem being addressed or
program being implemented. For example, budget needs may differ
depending on whether a regulatory program is implemented at the Federal
level or is primarily implemented by the States. As another example, a
program aimed at reducing risk through public education may have
different budget needs compared to a program that provides technical
assistance.
This is not a complete discussion of all the factors that enter
into EPA's priority-setting processes. Other hard-to-quantify
considerations, like intergenerational equity and environmental
justice, also have to be weighed. For our purposes here today, I simply
want to emphasize that comparative risk assessment provides a useful
mechanism for helping us think about environmental priorities, but by
itself it cannot provide any complete answers.
comparative risk assessment in strategic planning and budgeting
An important area in which comparative risk information comes into
play is in the Agency's planning, priority-setting, and budgeting
processes. As required by the Government Performance and Results Act
(GPRA), EPA developed a 5-year Strategic Plan in 1997, Annual
Performance Plans for Fiscal Years 1999 through 2001, and an Annual
Performance Report for Fiscal Year 1999. I want to emphasize that EPA
is one of the few, if not the only, agency to restructure its budget to
match the goal and objective structure of its Strategic Plan. This
allows Agency decisionmakers, Congress, and the public to identify the
resources associated with each of the Agency's goals and objectives,
and to compare the prospective benefits of these long-term outcomes
when making judgments about the Agency's proposed priorities and
funding.
In setting its strategic goals and objectives and developing
specific budget proposals to achieve them, the Agency uses the best
available scientific and economic analysis. The performance targets
identified in the Strategic Plan, such as the objective of having 95
percent of the population served by community water systems receive
water that meets national health standards by 2005, reflect the
Agency's decisions on the relative priority the Agency will place on
different environmental problems and programs. In communicating our
GPRA goals and objectives, annual performance targets, and actual
performance, the Agency has attempted to characterize for Congress and
the public the nature of the different health and environmental risks
that our programs are addressing.
With regard to annual budgets, comparative risk considerations have
been explicitly factored into various internal Agency-wide budget
investment and reduction exercises. As an example, our Office of
Research and Development uses information on the relative risks
associated with environmental problems in its annual cross-goal ranking
used in determining research priorities. Furthermore, it would be fair
to State that risk information, when available and relevant, is
implicitly included in most discretionary decisions made by Agency
program managers, both in setting priorities within major programs and
allocating resources across programs.
In recent budget formulation exercises, internal budget guidance
specifically required that Agency investment proposals characterize
human and ecological risk reductions. While risk information plays a
role, GPRA priority-setting and resource allocation decisions are
generally made on the basis of multiple criteria. Costs and benefits,
equity, institutional and legal feasibility, statutory mandates and
other Congressional direction, public values, risk tradeoffs, and
governmentwide priorities represent some of the factors that enter into
budget discussions and decisions.
Many challenges face EPA, Congress, and the interested public in
better using comparative risk information in environmental priority-
setting and budgeting. Availability of cost and risk data is improving,
but varies greatly across and within EPA programs. Methodologies for
assessing risk and benefits are at varying stages of development.
Finally, the diverse endpoints being addressed by environmental
programs--such as cancer versus non-cancer health effects, human health
versus ecological protection, reduction of chronic exposures versus
prevention of low-probability but high-risk chemical spills and
accidents make direct comparisons of risks and benefits difficult. As
we work to improve comparative risk data and tools for use in priority-
setting and budgeting, EPA also will continue to improve the links
between its budget and its GPRA goals and objectives in order to
facilitate the ongoing dialog with Congress and stakeholders about our
priorities.
comparative risk assessment in epa/state/tribal partnerships
A strong partnership between EPA and State and tribal governments
has always been one of the most important and effective aspects of U.S.
environmental policy. As comparative risk assessments have become more
sophisticated and useful over time, they have been incorporated into
the EPA/state/tribal partnership in several fundamental ways.
For example, from the time that EPA and the SAB first began to
assess and prioritize relative risks, the Agency has encouraged and
supported similar processes by states, communities, and Native American
tribes. Between 1990 and 1999 EPA provided financial and technical
assistance to states, localities, tribes, and watershed organizations
to support comparative risk projects of their choosing. EPA provided
expert advice on the process, developed resource materials, supported
communications among project directors, and paid for project startup
costs. EPA required all parties involved to meet general project
criteria, but the participants decided how they would apply the
criteria, and they could use comparative risk assessments to meet their
unique purposes. During the decade of the 1990's EPA provided about one
million dollars a year to support these comparative risk assessment
activities.
In most cases, the projects resulted in a much clearer
understanding of local environmental challenges, and sometimes they
inspired new environmental initiatives. The results of EPA-supported
comparative risk assessments also led to the funding of several
environmental risk-management initiatives that were already under
consideration by State and local governments at the time. At EPA we are
very proud of these accomplishments, and I think the State and local
representatives you will hear from today will agree.
As these critical partnerships have evolved over the past decade,
comparative risk assessments have played an increasingly important
role. Because of our shared commitment to improving public health and
environmental quality, in 1995 EPA and the states jointly entered into
a new National Environmental Performance Partnership System, or NEPPS.
This stronger, more collaborative partnership emphasizes that EPA and
the states are mutually dependent on each other in our respective
efforts to reach our shared environmental goals. Through NEPPS EPA and
the states jointly set priorities for action, and we work together to
clarify our roles and responsibilities.
The centerpiece of NEPPS is Performance Partnership Agreements
(PPAs) between EPA and individual states. The PPA is the mechanism that
allows each state, in conjunction with EPA, to set priorities, solve
problems, and make the most effective use of our collective resources.
Comparative risk assessment is one of the management tools used by
states to determine which programs they want to target for improvement
or strengthening as part of their PPAs. These agreements thus give
states greater freedom to focus their resources on their highest
environmental priorities, and comparative risk assessment is one way
those priorities can be established. However, like EPA, states must
comply with Federal environmental requirements regardless of their
considerations of comparative risk.
Under NEPPS the states also have more flexibility in administering
EPA grant funds. With our new Performance Partnership Grants (PPGs),
states now can consolidate a variety of individual grants into one.
That kind of simplification and consolidation can be driven by
comparative risk assessment. For example, if a comparative risk
analysis showed that a particular source of drinking water poses
relatively high risks, a State could combine funding for drinking water
and solid waste programs and target it at the program in need of
supplemental funding. Here again, greater flexibility and comparative
risk assessment come together to strengthen a traditional partnership.
Let me give you an example of how this works in practice.
Delaware's Department of Natural Resources and Environmental Control
(DNREC) was the first to utilize a so-called ``logic model,'' which
uses comparative risk assessment to help set priorities. Different
categories of environmental information were organized to reflect
environmental conditions, stressors, and pollution sources. The DNREC
then developed a self-assessment that addressed the department's
activities and capabilities in relation to this information. The
subsequent Performance Partnership Agreement contained joint EPA/state
priorities and initiatives that reflected the environmental and program
needs identified by the self-assessment. In short, comparative risk
assessment was one of the primary forces shaping Delaware's PPA.
comparative risk assessment in epa's regulatory programs
To some extent, comparative risk assessment is used in many of
EPA's regulatory programs. I would like to describe three in more
detail, because that will give you a sense of how comparative risk
assessment has been integrated into the Agency's more traditional
activities.
For example, EPA is using comparative risk assessments to help set
priorities in its program to control toxic air pollutants. Under
Section 112(e) of the Clean Air Act, EPA is required to develop a
Source Category Schedule (SCS) for promulgating Federal emissions
standards for 174 categories of sources of toxic air emissions. In
determining scheduling priorities, the law requires EPA to consider
three criteria: (1) the adverse effects of the different hazardous air
pollutants; (2) the quantity and location of emissions of each
pollutant; and (3) the relative efficiency of different groupings of
source categories or subcategories. To help develop this schedule, EPA
established a system that combines emissions estimates, health effects
data, and limited population information in order to generate an
approximate idea of the comparative risks of the various source
categories. This system was used in conjunction with other
considerations, such as work load efficiency and the time needed to
develop different standards, to establish the Source Category Schedule.
EPA also has used a form of comparative risk assessment in
developing our Integrated Urban Air Toxics Strategy under Section
112(k) of the Clean Air Act. The law requires EPA to identify at least
30 pollutants that pose the greatest threat to public health in the
largest number of urban areas. To address this requirement, EPA
developed a methodology composed of three separate ranking analyses
that each relied on information relevant to risk assessment, such as
toxicity, emissions, ambient monitoring, and air quality modeling. We
integrated the results of the three analyses to obtain the list of 33
urban hazardous air pollutants that will guide our actions under the
strategy to protect public health in urban areas.
As in the air program, many of the priorities in our national water
program are guided by the principle of addressing the highest risks
first. For example, the Safe Drinking Water Act of 1996 provides clear
direction to the Agency to focus on contaminants of greatest risk.
Consequently, over the last few years EPA has issued a number of
regulatory actions aimed at controlling high risk contaminants such as
disinfectants and disinfectant byproducts. We have proposed criteria
for determining when disinfection is required for underground drinking
water sources, and proposed added protections for smaller drinking
water systems. In addition, EPA now is gathering data on the occurrence
and health effects of other contaminants. These data will help the
Agency make sound decisions in the future about which drinking water
contaminants are high-risk and warrant regulation, while also helping
set priorities for drinking water research, monitoring, and guidance
development, including health advisories.
comparative risk assessment in voluntary programs
Over the past decade, EPA has augmented its traditional regulatory
programs with a variety of voluntary partnerships that can be targeted
at either regulated or unregulated pollutants. These programs have
proven to be remarkably successful, because many businesses have begun
to realize that there is a strong linkage between economic and
environmental performance. In most cases, as businesses become
efficient and reduce or eliminate waste streams, they become more
profitable. For these and other reasons, many businesses today are
demonstrating environmental stewardship and improving environmental
performance in ways that go beyond what government regulations require.
The growth of voluntary partnership programs in the 1990's occurred
at the same time that the techniques of comparative risk assessment
were becoming more sophisticated and more widely applied. As a
consequence, many voluntary risk-reduction efforts--whether conducted
by EPA, private businesses, or jointly--include a comparative risk
component.
For example, EPA today is trying to find more effective,
integrated, and comprehensive solutions to the complex environmental
problems caused by specific industry sectors. At the same time, we want
to reduce the regulatory burden on those same industry sectors. To meet
those goals, we have initiated a sectors program that takes a more
strategic approach to environmental protection. We tailor a set of
actions--some required by regulation and some voluntary--to address the
unique environmental issues, needs, and opportunities presented by
different industries. The strategic design and subsequent
implementation of these sector programs involve comparative risk
assessments as part of the priority-setting process.
When EPA works in partnership with a particular industry sector, we
jointly design a targeted set of effective actions that achieve
cleaner, cheaper, smarter environmental results. This priority-setting
process involves a comparative analysis of the industry's most
significant environmental impacts and the likely effects of possible
actions to address those problems. This analysis may not take the form
of an in-depth, scientific study, but it does involve thorough
consideration of existing data sources, current environmental
priorities, and expert stakeholder perspectives. The end result is a
tailored, sector-specific action plan that, by definition, reflects the
sector's comparative risk profile.
For example, EPA's metal finishing sector stewardship program
started with a comparative assessment of that industry's multiple
environmental impacts. The stakeholders involved, including EPA and
industry representatives, reached the common conclusion that the
greatest environmental stewardship opportunities in this industry
sector were water and energy conservation, reduced metals loadings, and
reduced sludge generation. EPA then was able to work with the industry
and other stakeholders to develop a first-of-its-kind stewardship
program that set voluntary performance targets for those key
environmental parameters.
Many of the innovative ideas developed and tested at EPA over the
past decade have come together in a new program that the EPA
Administrator announced on June 26. Called Performance Track, this
program encourages businesses to do more than the law requires to
protect human health and the environment. For those businesses that
show exemplary environmental stewardship, EPA is going to reward them
with a package of benefits that will include lower costs, streamlined
administrative operations, and public recognition.
One of the most important actions that we're requiring of
Performance Track participants is that they put in place a vigorous
environmental management system. These management systems will have to
include several specific components, including a facility-wide
commitment to pollution prevention, environmental training for all
employees, and an emergency preparedness program. We'll also expect
participating companies to set specific performance targets and then
hit those targets successfully.
And that's where comparative risk assessment will prove valuable.
In their environmental management systems companies will have to
characterize their environmental emissions, assess the health and
ecological risks they entail, and then set risk-based priorities for
improving their performance over time. In this sense comparative risk
assessments lie at the heart of environmental management systems, and
thus they will play an integral role in EPA's Performance Track
program.
conclusion
As these examples demonstrate, over the past decade comparative
risk assessment has emerged as an important priority-setting tool at
EPA. In most cases, more complete data bases and more sophisticated
methodologies would lead to more robust results, and so at EPA we're
continually working to improve our capabilities to conduct comparative
risk assessments.
At the same time, I want to emphasize that these assessments will
never, by themselves, provide an unambiguous, bright-line way of
ranking the Agency's management priorities. No matter how much data we
collect or how much further the methodologies evolve, the reality of
risk reduction will always demand a large measure of judgment related
to ethics, equity, and economics. Widespread public concerns, for
example, may raise the profile of a particular risk and necessitate
early and forceful Agency action, even if the risk is not very high
when compared to other Agency programs. We sometimes may act to control
relatively less serious risks if available risk management options are
cheaper and more effective. And sometimes we have to apply simple human
judgment when deciding on the relative importance of controlling risks
to humans versus risks to ecosystems, or risks to current generations
versus risks to the future.
In short, when setting priorities for budgets and actions, EPA has
to consider a range of factors, one of which is comparative risk
assessment. I believe we are using such assessments well today, and we
will use them even more effectively in the future. But even as we
improve their use and effectiveness, we should not lose sight of their
inherent limitations.
Thank you very much.
______
Responses of Al McGartland to Additional Questions from Senator Smith
Question 1. In its report entitled ``Strengthening Science and Peer
Review at EPA'', the NRC concluded that:
Scientific knowledge and technical information are essential
for determining which environmental problems pose important
risks to human health, ecosystems, the quality of life, and the
economy. We need scientific information to avoid wastefully
targeting inconsequential problems while ignoring greater
risks. We need such information to reduce uncertainties in
environmental decisionmaking and to help develop cost-effective
strategies to reduce risk. We need science to help identify
emerging and future environmental problems and to prepare for
the inevitable surprises.
Do you agree? Please explain what EPA actions are being taken in
that regard.
Response. We agree that scientific knowledge and technical
information are essential components in the evaluation of environmental
problems. As stated in our Strategic Plan, EPA strives to ensure that
its efforts to reduce environmental risk are based on the best
available scientific information. In its implementation of the
Government Performance and Results Act (GPRA), EPA established a
strategic planning framework comprising 10 strategic goals with
associated long-term objectives. Goal 8 of that framework, Sound
Science, emphasizes EPA's commitment to (1) identify the most important
sources of risk to public health and the environment and thereby guide
Agency decisions, and (2) anticipate environmental and other changes
that might portend future environmental risk and integrate futures
thinking into Agency planning.
There are many examples of actions EPA has taken to enhance the use
of sound, credible, and relevant science in Agency decisionmaking. One
example is the Office of Research and Development (ORD) Strategic Plan,
which complements the Agency's Strategic Plan and identifies risk-based
criteria for establishing research priorities. Using these criteria,
ORD has identified eight high-priority areas where significant levels
of input will be required for EPA decisionmaking now and in the future.
These research areas will include issues such as: understanding the
health risks of exposure to fine particles in air pollution, preserving
safe drinking water, and research to improve ecological risk
assessment.
Because science activities take place throughout EPA, the cross-
agency Science Policy Council is building on the ORD development of
both an Agency-wide inventory of scientific activities and a
``Strategic Framework for EPA Science'' in planning EPA scientific and
research activities that focus on the most important environmental
risks. Importantly, the technical products that result from these
efforts are peer reviewed, thereby ensuring the best and most relevant
science is used in Agency actions and decisions. In the area of
anticipating future environmental problems, ORD is building upon the
National Academy of Public Administration report, ``Remembering the
Future: Applying Foresight Techniques to Research Planning at EPA'' to
apply the concept of futures in its research planning.
Additionally, in October 1999, the Administrator created a new
Office of Environmental Information (OEI) that has central
responsibility over information management, policy and technology
because of the growing demand for high-quality environmental
information. Creating the office was a collaborative process with input
from a wide range of staff and stakeholders, both internal and external
to EPA. OEI activities such as strengthening information partnerships,
enhancing information quality, and communicating the utility of
environmental information will help the Agency to foster information-
based decisionmaking. We also hope these activities will generate new
trend and outcome-information to promote adaptive and forward-looking
environmental management by decisionmakers at all levels.
These examples illustrate some of the steps that EPA has taken to
incorporate scientific, technological, and environmental information
into the environmental decisionmaking process.
Question 2. Michael J. Pompili, Assistant Health Commissioner,
Columbus Health Department Columbus, Ohio testified that:
At one time, the Federal Government funded a U.S. EPA office
to directly assist State and local folks interested in doing
this type of work. This Regional and Statistical Planning
Branch of the Office of Policy, Planning and Evaluation was
extremely helpful to us in Columbus providing a $50k grant for
our project and direct technical assistance in project
formation and implementation. I have heard many other local
project directors share these sentiments. Unfortunately, the
office was disbanded a year or so ago and its personnel were
reassigned within the Agency. To my knowledge, there is now no
Federal entity that exists concerned with promoting and
directly assisting State and local governments with projects
dealing with risk-based decisionmaking.
Please explain why that office was disbanded and what is EPA doing
to reinstate support for State and local governments with projects
dealing with risk-informed decisionmaking.
Response. The Agency operated a comparative risk program for
approximately 7 to 8 years. During that time, we made large
contributions to State and local governments for conducting risk
assessments. State and local governments have continued to use the
tools and methods that we shared during that time to set their
priorities. Two years ago, we shifted our comparative risk staff and
resources to focus on the Agency's implementation of the President's
Clean Water Action Plan.
We continue to encourage our State and local counterparts to
incorporate risk and other factors into their priority-setting process.
As part of the National Environmental Performance Partnership System,
EPA Regional Offices work with our State counterparts in joint planning
and priority setting. These efforts are based upon an analysis of
environmental information and State and local conditions to determine
the environmental problems that deserve the highest attention.
Environmental information is coupled with risk assessment to identify
the most significant State and local environmental problems. The State
Agency and EPA Regional Office then develop work plans to address these
problems.
The State/EPA work plans are contained within Performance
Partnership Agreements or other similar documents outlining the
priorities, what actions will be taken by which agency, and how State
assistance grants will be used to accomplish this work. Under current
guidelines and a proposed new regulation governing State assistance
grants (the Part 35 rule), EPA and States work together to determine
comparative risks and set priorities. With a Performance Partnership
Grant (PPG), a State can combine two or more of 16 different
categorical grants into a PPG to have funding flexibility to address
the highest priority risks. States are encouraged to involve the public
in this process of determining priorities.
Some of our program offices also offer assistance to communities
for evaluation of local environmental problems. For example, we have a
program called the Technical Outreach Services for Communities (TOSC),
which is a service of the Hazardous Substance Research Centers program
and the Superfund program. Through the TOSC program, communities have
access to independent technical advisors through universities. TOSC has
helped 118 communities understand the issues and solve problems dealing
with hazardous substance contamination.
Question 3. Under executive order 12866, EPA prepares detailed
cost-benefit analyses for all economically significant regulations.
Under that order, EPA also is to review, periodically, existing
regulations that are economically significant to determine if they can
be made more effective or less burdensome. How effective has EPA been
in carrying out those responsibilities? What would EPA do if a proposed
regulation did not pass the benefit-cost test?
Response. (a) How effective has EPA been in carrying out those
responsibilities? EPA has a strong record of success under the
``lookback'' provision of Executive Order 12866. In 1995, in response
to the President's request, EPA conducted a page-by-page review of all
its regulations and removed over 1200 pages of regulations from the
Federal Register. Subsequent to that effort, EPA has reached out to the
regulated community to identify cheaper, cleaner, and smarter ways to
achieve needed environmental improvements than those codified in
existing regulations, including those that are deemed economically
significant. Two of our major initiatives in this direction have taken
place under the auspices of the Common Sense Initiative and Project XL.
A sample of recent improvements stemming from our ongoing review of
existing rules includes:
Proposal for a Consolidated Air Rule for Chemical Manufacturers.--A
newly issued rule that consolidates 16 Federal air regulations into a
single guideline could save the average U.S. chemical plant about 1,700
hours or $80,000 a year. The regulation, which represents the first
consolidated rule ever under the Clean Air Act, would afford plant
managers a choice. The facility managers could opt to comply with the
consolidated rule or continue operating under the existing 16 rules.
Streamlined Certification Process for Auto Makers.--A streamlined
process for certifying that new passenger cars and trucks meet Federal
standards for air pollution emissions is expected to save automobile
manufacturers an estimated $55 million a year. Under the proposed
process, testing would be performed on vehicles actually in use on the
Nation's highways rather than on brand new vehicles. In addition to
cutting burden, the new process creates an incentive for manufacturers
to produce more durable emissions-control equipment and gives EPA
better date for managing air quality programs.
Simplified Hazardous Waste Management Requirements.--the Agency
addressed several barriers that have prevented common-sense practices
in managing hazardous wastes. Reforms to the 20-year-old program for
managing polychlorinated biphenyls (PCBs) are expected to produce cost
savings estimated between $178 million and $736 million each year.
Another regulatory revision simplifies the cleanup and closure of
hazardous-waste disposal facilities.
Compliance Alternatives for Small Drinking Water Systems.--Under
new flexibility offered under the 1996 amendments to the Safe Drinking
Water Act, EPA issued regulations to give small-community water systems
less expensive treatment alternatives to comply with Federal drinking
water standards in the future. Smaller systems can also request more
time to achieve compliance and variances from Federal requirements, as
long as such actions do not threaten public health.
Lowering the Cost of Lead-Based Paint Disposal.--Based on studies
showing that lead-based paint debris could be safely placed in ordinary
landfills (under the Toxic Substances Control Act), EPA proposed that
this disposal option be provided as an alternative to the traditional,
but more expensive disposal currently required under hazardous waste
regulations.
(b) What would EPA do if a proposed regulation did not pass the
benefit-cost test? The Agency uses the benefit-cost analyses it
conducts under Executive Order 12866 as a tool in the decisionmaking
process. The key goal of the economic analyses is to provide
policymakers with information on the potential consequences of
environmental policies. Executive Order 12866 says that Agencies should
adopt approaches that ``maximize net benefits (including potential
economic, environmental, public health and safety, and other
advantages; distributive impacts; and equity), unless a statute
requires another regulatory approach.'' However, it is often difficult
to determine which regulatory options will maximize net benefits
because quantitative environmental and health effects data (e.g., air
or water quality, risk factors) are often not available or are sparse.
This constraint means that many benefits and cost categories cannot be
expressed in monetary terms, which then constrains the use of benefit-
cost analyses in the public policy decisionmaking process. Thus, a
strict comparison of monetized benefits and costs should not be used in
making policy decisions.
Additionally, economic efficiency should not be the sole criterion
for developing good public policies because a large number of social
goals and constraints motivate and shape environmental policy. For
example, the Agency considers environmental justice issues, statutory
and judicial mandates, institutional constraints, technical
feasibility, and enforceability in the regulatory policy process. Even
the most comprehensive economic analyses are but part of a larger
policy development process, one in which no individual analytical
feature or empirical finding dominates. The results of our benefit-cost
analyses serve as important inputs for this broader policymaking
process along with other analyses and considerations.
Question 4. Looking back at the last thirty years, what lessons has
the Agency learned about improving environmental decisionmaking using:
(a) an integrated approach, (b) a risk-informed approach, and (c)
benefit-cost analysis.
Response. Looking back in time, the Agency has learned much about
using various approaches to managing environmental problems. Following
are our experiences with some of these approaches:
(a) An integrated approach.--There are many complex, high-profile
issues (e.g., children's health, contaminated sediments) that do not
easily fit into a single EPA office or a media-specific approach, but
nevertheless must be addressed because of the significant environmental
problems they represent. EPA has learned that finding solutions to
these issues means looking beyond traditional environmental media and
programmatic boundaries.
The changing nature of environmental protection with greater
attention to multiple stressors, cumulative risk, non-regulatory policy
approaches, globalization, and enhanced public access means that
science must be integrated across media and programs. EPA has
established new offices (such as the Office of Children's Health
Protection) and initiatives (such as the Persistent, Bioaccumulative,
Toxic chemicals (PBT) Initiative) that recognize the necessity for
employing an integrated approach. The Office of Research and
Development's (ORD) Strategic Plan for 2000 identifies ``Integrate
Environmental Science and Technology to Solve Environmental Problems''
as one of ORD's five goals for the coming decade. In addition, the
Agency is developing an enhanced ``EPA-Wide Inventory of Science
Activities'' that will facilitate cross-agency science integration.
Collaboration among technical experts from across the Agency, as
well as the cross-program/media integration of information, provides
opportunities for synergism in the scientific process. For example, the
Agency's highly successful experience over the past several years with
promoting scientist to scientist meetings on important environmental
topics bears this out. Efforts to enhance scientific collaboration and
integration will increase over the coming years. In this way, the
Agency can carry out its mission with a growing understanding of
environmental problems in a multimedia context that focuses attention
on the greatest risks.
(b) A risk-informed approach.--Agency decisionmakers recognize that
risk assessment and other scientific information can guide
decisionmaking at EPA. Scientific inquiry, investigation, and
information lead to the identification of potential risks to human
health and the environment, and also point the way toward addressing
those risks. Risk assessment weighs heavily in Agency decisions and, as
appropriate, these assessments are joined with other scientific
information, such as economic data and engineering studies, to provide
scientific input to Agency decisions.
Because of the critical role risk assessment plays in environmental
decisionmaking, EPA has developed a framework for ecological
assessment, cancer assessment guidelines, and other risk assessment
tools. These tools promote consistency across the Agency in how risk
assessments are performed and used in Agency decisions. Research to
improve human health risk assessment and ecological risk assessment
represent two of the highest priority research areas of the Agency's
Office of Research and Development.
(c) Benefit-cost analysis.--Agency decisionmakers recognize that
benefit-cost analysis can be a meaningful tool for environmental
decisionmaking, along with other analyses and considerations. A
thorough benefit-cost analysis of proposed regulatory alternatives can
assist the Agency in developing control requirements that achieve the
highest environmental quality and human health standards at the lowest
costs. The Agency has learned the importance of developing better ways
to measure benefits and costs in order to more meaningfully inform
decisionmakers, the importance of communicating information about
benefits and cost categories that cannot be monetized, and the
importance of working to achieve consistency in our economic analyses
across the Agency.
Despite the greater use and prominence of benefit-cost analysis in
the environmental policymaking process, it is still only possible to
quantify a limited subset of all the important benefits and costs
associated with regulatory options. In most instances, significant
benefit categories remain unquantified and unvalued. For example, in
EPA's Clean Air Act (CAA) Section 812 study, a benefit-cost analysis of
the entire CAA, some of the numerous unquantified benefits include:
ecological effects, materials damage, behavioral effects, developmental
effects, agricultural effects, eutrophication, acid deposition and many
human health effects. This limitation also affects the Agency's ability
to assess broad programs or strategic long run plans aimed at informing
budgeting and planning decisions within public and private agencies.
Our inability to quantify and value important benefit categories limits
the contribution that benefit cost analysis can add to the policymaking
process is necessarily constrained.
The Agency is taking a number of steps to address these problems.
An important function of the Agency's newly formed National Center for
Environmental Economics (NCEE) is to develop data and methods for
benefit and cost assessments through research aimed at filling priority
needs common to many programs in the Agency. NCEE is actively
performing innovative research on new and improved methods and
incorporating cutting-edge advances in the field. In addition, NCEE
promotes efforts by academics and EPA staff to improve the means to
value costs and benefits. NCEE also works to communicate EPA's research
priorities to economics professionals across the Nation, thereby
helping to focus their expertise and own resources to better meet EPA's
needs.
EPA will soon release its Guidelines for Preparing Economic
Analyses, which establish a sound scientific framework for performing
economic analyses of environmental regulations and policies. They
incorporate recent advances in theoretical and applied work in the
field of environmental economics, and specifically address the issues
of valuation of benefits, presentation of uncertainties in analysis,
and consideration of regulatory alternatives. The Guidelines will help
ensure that important subjects such as uncertainty, sensitivity
analysis, timing, and valuation of costs and benefits, are treated
consistently in all economic analyses prepared to inform at EPA's
decisionmakers.
Question 5. Why is the Agency's Strategic Plan still an inherently
output-oriented plan as opposed to a result-oriented one? Please
specify EPA actions in that regard.
Response. The Strategic Plan represents a balance between outcomes
and outputs. The Agency's Plan covers all the major functions and
activities of EPA and therefore strikes an appropriate balance between
the management functions and the environmental results we are trying to
achieve. Since the issuance of the 1997 Strategic Plan, the Office of
Chief Financial Officer (OCFO) has also worked closely with EPA's
program offices through the Annual Plan process and more recently via
the revision of the Strategic Plan in improving the measurability and
outcome orientation of the Agency's strategic architecture of goals and
objectives and performance goals and measures.
Response. In pursuit of strong outcome orientation of the goals and
measures, the Agency formed the Performance Measurement Improvement
Team. The primary objective of this Team is to work with EPA's programs
in their efforts to increase the general quality and outcome
orientation of the Agency's performance goals and measures. The Team is
involved in efforts such as workshops and training sessions, on-going
analyses of annual goals and measures, and Goal-specific performance
measurement improvement projects. In addition, our process for revising
the Plan incorporated numerous opportunities for providing feedback to
the program offices on their proposed revisions to the strategic
architecture. Through these processes, we noted substantial improvement
in the objective statements incorporated in the 2000 Strategic Plan;
half of the objectives in the Plan are environmental outcome-oriented.
EPA continues to work both internally and with our partners to
strengthen the outcome orientation and measurability of the Agency's
strategic architecture of goals and objectives. For example, two
significant obstacles that impede EPA's efforts in developing outcome-
oriented metrics are the lack of data on environmental conditions
(e.g., the current State of public health and the environment) and the
difficulties associated with establishing a direct relationship between
these parameters, which are also impacted by many other factors. EPA is
conducting and funding research to help provide some of the information
and methodologies necessary to overcome these obstacles. First, we are
helping to develop and collect baseline data on environmental
conditions. In collaboration with the states and other Federal
agencies, we are monitoring and measuring indicators of ecological
health, such as fish populations and stream concentrations of dissolved
oxygen. These indicators will allow us to estimate conditions of the
Nation's ecological resources with known degree of confidence.
Similarly, the Centers for Disease Control provide estimates of public
health, and we are working with them to collect data on exposure to
environmental contaminants to further our understanding of the
relationships between exposure reductions and improved health.
These activities will serve as the foundation for outcome-oriented
performance measures, helping us improve our Strategic Plan to reflect
the results of our work.
Question 6. How is the Agency addressing GAO's recommendations
regarding data gaps, poor quality of available data, and
inconsistencies in data-bases?
Response. EPA has recently initiated the first stage of a multi-
phase effort to develop an Agency ``Information Plan.'' The first phase
will identify broad options for information management by the Agency
over the next several years and the associated implications.
Implementation of the plan will transform how the Agency manages its
information assets (the people, policies, data, and technology) so that
EPA can better provide integrated, timely, and cost-effective access to
accurate information to decisionmakers and the public. Phase I of the
plan will identify strategic choices facing EPA such as the need to
address current and future information needs. We expect to complete the
first phase of the Information Plan in December 2000.
With respect to data quality and inconsistency, EPA is pursuing
several activities to address these issues. First, the Agency is
developing a Data Quality Plan to evaluate the life-cycle of data
collection, management and use in EPA in order to identify those places
where quality vulnerabilities exist. This information will lead to
follow-up actions by the program offices responsible for the data and
information. Second, the Agency has created an ``integrated error
correction process'' which allows users of the national data systems to
report known or suspected data errors. In this process, EPA and State
data stewards research the reported error, make corrections in the data
bases if appropriate, and report back to the individual on the action
taken. This process was established in June 2000 and is now active for
the information systems in EPA's Envirofacts data warehouse; the
process will be added to additional systems in fiscal year 2001. Third,
EPA's data standards program is improving the consistency of the
information collected and used by the Agency. EPA has developed and
approved the six major data standards in the Reinventing Environmental
Information program. More recently, we joined with the Environmental
Council of the States and with representatives of Indian Tribes to
create the Environmental Data Standards Council, a cooperative effort
to develop and implement additional data standards. The Council is now
pursuing the development of four additional data standards. Taken
together, these actions will lead to the data quality improvements
sought by all concerned.
Question 7. Asked by Chairman Smith during hearing on October 3,
2000. (paraphrased) There is no Federal entity that promotes and
directly assists any State and local government with risk-based
decisionmaking. Is there any entity within your Agency to do that?
Response. As we explained in our answer to Question No. 2, we
continue to encourage our State and local counterparts to incorporate
risk and other factors into their priority-setting process. As part of
the National Environmental Performance Partnership System, EPA Regional
Offices work with our State counterparts in joint planning and priority
setting. These efforts are based upon an analysis of environmental
information and State and local conditions to determine the State and
local environmental problems that deserve the highest attention.
Environmental information is coupled with risk assessment to identify
the most significant environmental problems. The State Agency and EPA
Regional Office then develop work plans to address these problems.
The State/EPA work plans are contained within Performance
Partnership Agreements or other similar documents outlining the
priorities, what actions will be taken by which agency, and how State
assistance grants will be used to accomplish this work. Under current
guidelines and a proposed new regulation governing State assistance
grants (the Part 35 rule), EPA and States work together to determine
comparative risks and set priorities. With a Performance Partnership
Grant (PFG), a State can combine 2 or more of 16 different categorical
grants into a PPG to have funding flexibility to address the highest
priority risks. States are encourage to involve the public in this
process of determining priorities.
In addition, EPA has developed and updated numerous risk assessment
guidelines and related documents over the last 15 years. These
guidelines, addressing such diverse risk assessment issues as
carcinogenicity, reproductive health, exposure, pollutant mixtures, and
ecological effects, are published by the Agency following peer review.
The published guidelines are often used by state, local, and tribal
governments (as well as the international community) as they consider
how to develop and use risk assessments for their programs.
______
Responses of Al McGartland to Additional Questions from Senator Baucus
Question 1. The testimony by GAO cites numerous concerns, including
data gaps, data base incompatibilities, and data inaccuracy, as well as
failures in integrating measured outcomes with EPA programs. You
indicated that the Agency is developing a strategic plan that responds
to these concerns. Please describe that plan in as much detail as
possible. When will it be completed and available for review by the
committee?
Response. As we responded to Chairman Smith's Question No. 6, EPA
has recently initiated the first stage of a multi-phase effort to
develop an Agency ``Information Plan.'' The first phase will identify
broad options for information management by the Agency over the next
several years and the associated implications. Implementation of the
plan will transform how the Agency manages its information assets (the
people, policies, data, and technology) so that EPA can better provide
integrated, timely, and cost-effective access to accurate information
to decisionmakers and the public. Phase I of the plan will identify
strategic choices facing EPA such as the need to address current and
future information needs. We expect to complete the first phase of the
Information Plan in December 2000.
With respect to data quality and inconsistency, EPA is pursuing
several activities to address these issues. First, the Agency is
developing a Data Quality Plan to evaluate the life-cycle of data
collection, management and use in EPA in order to identify those places
where quality vulnerabilities exist. This information will lead to
follow-up actions by the programs responsible for the data and
information. Second, the Agency has created an ``integrated error
correction process' which allows users of the national data systems to
report known or suspected data errors. In this process, EPA and State
data stewards research the reported error, make corrections in the data
bases if appropriate, and report back to the individual on the action
taken. 'this process was established in June 2000 and is now active for
the information systems in EPA's Envirofacts data warehouse; the
process will be added to additional systems in fiscal year 2001. Third,
EPA's data standards program is improving the consistency of the
information collected and used by the Agency. EPA has developed and
approved the six major data standards in the Reinventing Environmental
Information program. More recently, we joined with the Environmental
Council of the States and with representatives of Indian Tribes to
create the Environmental Data Standards Council, a cooperative effort
to develop and implement additional data standards. The Council is now
pursuing the development of four additional data standards. Taken
together, these actions will lead to the data quality improvements
sought by all concerned.
Question 2. What is the recent history of EPA's requests for
environmental data collection funding and Congress's appropriation of
these requested funds?
Response. Environmental data collection is an activity that is
vital to the mission of the Agency and supports the goals and
objectives of our program offices. It is spread throughout EPA's
overall budget. EPA is working closely with our many partners and
stakeholders in trying to improve our information collection programs.
The Agency's data collection is an element of two annual reports
submitted to OMB: ``Report on Information Technology;'' and ``Capital
Assets Plan and Justification.'' These reports contain information on
the amounts budgeted for all aspects of information technology
including resources directly involved in data collection activities
managed by various Agency offices.
Question 3. We heard testimony about the New Hampshire and
Columbus, Ohio comparative risk projects. Has EPA supported,
financially, technically, or otherwise, these projects or other similar
projects on a local, state, or regional level? Hay the Agency used any
of the results from these projects to help inform national
environmental priorities?
Response. The Agency provided financial and technical assistance to
interested state, local, and tribal governments interested in
conducting comparative risk processes. The results of the projects were
used to improve environmental protection at the state, local and tribal
level. Although the results were not formally used in national priority
setting, EPA's program offices work directly with our Regional offices
(who had worked with the States to identify regional priorities) to
develop the Agency's strategic and annual plans. Additionally, EPA goal
teams engage in an extensive stakeholder outreach effort when
developing strategic objectives, and the Agency consults with State
organizations, such as EGOS, when developing its strategic plan.
Question 4. What is your reaction to having a national comparative
risk project performed and then using its results to determine EPA's
budget and regulatory priorities?
Response. Comparative risk analyses have become more widely
accepted as an input to the priority-setting process, and they have
been conducted by a number of State and local governments. For its
part, EPA has incorporated this useful tool unto our Agency-wide
strategic planning processes, into our partnerships with state, local,
and tribal governments, and into many specific programs, both
regulatory and non-regulatory. However, EPA is not using comparative
risk analysis as a brightline, mechanistic way of ordering the Agency's
priorities for either strategy, budgets, or actions.
One important limitation of comparative risk analysis is that there
is no common metric to evaluate the many kinds of risks that could be
addressed. This lack of a common metric raises many questions that
cannot be answered by scientific analysis alone. For example, EPA does
not typically engage in risk comparisons from widely variant activities
such as the risk from radon exposure compared to actuarially determined
traffic deaths. How do we incorporate the involuntary versus voluntary
nature of the exposure? Making comparative risk comparisons is
difficult even if the risks being compared are environmental in nature.
How does one compare the asthma problems associated with elevated ozone
to reproductive effects in ecosystems exposed to endocrine disrupting
chemicals? How should we compare skin cancer to throat cancer?
In addition to these comparative risk questions, a number of other
factors also have to be considered when the Agency sets its priorities:
Some of these factors, such as meeting statutory mandates and
responding to public concerns, are identified in our response to
Question No. 5. Moreover, decisions on some of these factors, such as
equity and environmental justice, require a degree of judgment that
cannot be answered through scientific analysis alone.
Question 5. What are the drawbacks or obstacles to having a
national comparative risk project performed and then using its results
to determine how EPA's budget should be allocated?
Response. Comparative risk assessment is a useful mechanism for
helping us think about environmental priorities, but comparative risk
assessment alone cannot provide complete answers. The Agency must
consider a number of factors, including but not limited to risk, when
setting its priorities. Some of these factors include statutory
mandates, community concerns, and the organizational structure of
various environmental programs. Additionally, a significant problem
inherent in the use of comparative risk assessment is the lack of a
common metric.
Many Federal environmental laws mandate specific actions. The
environmental statutes also often set timetables and deadlines for EPA
to take specified actions or accomplish specified goals. EPA has an
obligation to carry out the laws, which reflect the will of an elected
Congress and properly reflect considerations beyond comparative risk.
Community concerns also have to be considered when setting
environmental priorities. If a community believes that action must be
taken to solve what it considers to be a pressing environmental
problem, then EPA has an obligation to respond, even if the problem
does not seem to rank high on a list of comparative risks.
Another consideration in setting priorities is the different roles
that EPA has, depending the environmental problem being addressed or
program being implemented. For example, budget needs may differ
depending on whether a regulatory program is implemented at the Federal
level or is primarily implemented by the States. As another example, a
program aimed at reducing risk through public education may have
different budget needs compared to a program that provides technical
assistance.
As discussed in Answer #4 above, there is no common metric for
comparing the different kinds of risks that could be addressed. For
example, how can human health and ecological risks be incorporated into
the same risk ranking? How would we prioritize the risks associated
with pollutant exposures that may cause cancer in humans compared to
degraded water quality in the Chesapeake Bay that may deplete oyster
beds? The Science Advisory Board recognized this problem when they
wrote Reducing Risk and they did not attempt to include human health
and ecological risks in the same ranking.
This is not a complete discussion of the issues associated with
using comparative risk assessment alone to make national budget
decisions. Other hard-to-quantify considerations, such as distributive
impacts and environmental justice, also have to be considered.
Therefore, comparative risk assessment cannot be used as a bright line
mechanistic way of ordering the Agency's priorities for either
strategy, budgets, or actions because there is no one analytical method
that can address all of these issues.
Question 6. Please describe each of the data collection efforts
which EPA supports, conducts or uses, to get an accurate picture of the
Nation's public and environmental health.
Response. Under the Paperwork Reduction Act, the Agency is required
to obtain Office of Management and budget approval before it can ask
the public to submit information or retain records. In general, any
monitoring, reporting or recordkeeping requirements imposed on non-
Federal respondents will require an Information Collection Request
(ICR). EPA has about 350 active ICRs. EPA is developing a web-based,
searchable tool, called the Information Collection Request Inventory
(ICRI), based on these Information Collection Requests (ICRs). Once
completed, the inventory will enable EPA and the public to better
understand the types of information EPA collects, from whom, and the
cumulative impact of EPA's collection activities. We expect to complete
the ICR Inventory in the second quarter of fiscal year 2001.
__________
Statement of Peter F. Guerrero, Director, Environmental Protection
Issues, Resources, Community, and Economic Development Division,
General Accounting Office
Mr. Chairman and members of the committee: We appreciate the
opportunity to discuss our observations on the data that the
Environmental Protection Agency (EPA) needs to manage its programs more
effectively. In reports going back to our comprehensive general
management review of EPA in 1988,\1\ we have identified numerous long-
standing problems in the agency's efforts to collect and use
environmental data. Drawing from this work, I will discuss today the
limitations in the data that EPA needs to: (1) set risk-based
priorities for its programs and (2) develop outcome-oriented measures
of its programs' results. Our observations are as follows:
---------------------------------------------------------------------------
\1\ Environmental Protection Agency: Protecting Human Health and
the Environment Through Improved Management (GAO/RCED-88-101, Aug. 16,
1988).
---------------------------------------------------------------------------
EPA's ability to assess risks and establish risk-based
priorities has been hampered by data quality problems, including
critical data gaps, data bases that do not operate compatibly with one
another, and persistent concerns about the accuracy of the data in many
of EPA's data systems. While EPA's priorities should reflect an
understanding of relative risk to the environment and public health,
good data often do not exist to fully characterize risk. In the absence
of reliable data, public perceptions of risk can influence how EPA
determines its priorities and allocates resources. EPA has taken major
steps during the past few years to improve its data and to better
inform the scientific community and general public of environmental and
public health risks. To finish this job, the agency will need to expand
its data improvement initiatives to fill key gaps in its data, take
advantage of opportunities to develop and implement data standards to
achieve compatibility among environmental data bases, and ensure the
accuracy of its data.
Measuring the results (outcomes) of its programs is
critical to determining EPA's effectiveness. Nevertheless, the agency
historically has relied on activity-based output measures, such as the
number of inspections performed, because of inherent technical
difficulties in establishing sound linkages among program activities,
environmental improvements, and public health. Spurred by the
requirements of the Government Performance and Results Act of 1993
(Results Act), EPA has made progress in recent years in measuring the
outcomes of its programs. To ensure future success in developing
outcome measures, however, EPA will need to make a long-term management
commitment to overcome major challenges to obtaining the data needed to
show the results of environmental programs.
background
Since EPA's establishment in 1970, the Federal Government has
developed a complex system of laws and regulations to address the
Nation's environmental problems. Over the years, as environmental
threats were identified, the Congress responded by enacting laws to
address each problem, incrementally adding to the statutory framework
that sets EPA's agenda. However, these laws were not coordinated or
integrated to provide EPA with an overall system for prioritizing
problems so that the most serious problems can be addressed first.
Impelled by budgetary constraints and a growing list of
environmental problems, EPA, in the late 1980's, began to consider
whether its resources were being spent on the problems that pose the
greatest risks to public health and the environment. The agency
concluded that the Nation actually was devoting more resources to
problems that had captured public attention than to problems that were
less well known but potentially more serious. Subsequently, EPA began
incorporating the concept of relative health and environmental risk
into decisions on environmental priorities and emphasizing the need to
identify the most serious risks and to keep the public informed about
the relative seriousness of various environmental problems. To assess
risks and deal with those likely to do the most harm, EPA has
recognized that it needs to have adequate environmental and scientific
data to conduct risk assessments, set standards, and develop
regulations. It also needs such data to identify and develop measures
of environmental quality and to assess the effectiveness of its
programs by linking program activities to changes in environmental
conditions.
epa needs better data to establish risk-based program priorities
Establishing risk-based priorities for EPA's program activities
requires good data on the use and disposal of thousands of chemicals.
To assess human exposure to a chemical, EPA needs to know how many
workers, consumers, and others are exposed; how the exposure occurs;
and the amount and duration of the exposure. For environmental
exposure, EPA needs to know whether the chemical is being released to
the air, water, or land; how much is being released; and how wide an
area is being affected. EPA's ability to make such assessments is
limited by: (1) gaps in environmental and health data, (2) data bases
that do not operate compatibly with one another, and (3) the lack of an
effective system for ensuring the accuracy of the agency's data.
Although EPA has implemented several agencywide initiatives to address
these problems, each of the initiatives has encountered obstacles that
must be overcome to substantially improve the agency's data.
Extensive Gaps Exist in EPA's Information About the Environment and
Health Risks
Our work over the past few years has shown that very little is
known about the risks of potential exposure to chemicals and
environmental conditions for workers, the general public, and plant and
animal life. For example, we reported the following:
EPA's Integrated Risk Information System, which is a data
base of the agency's consensus on the potential health effects of
chronic exposure to various substances found in the environment, lacks
basic data on the toxicity of about two-thirds of the known hazardous
air pollutants.\2\
---------------------------------------------------------------------------
\2\ Major Management Challenges and Program Risks: Environmental
Protection Agency (GAO/OCG-99-17, Jan. 1999).
---------------------------------------------------------------------------
EPA's National Water Quality Inventory does not accurately
describe water quality conditions nationwide. Only 19 percent of the
Nation's rivers and streams were assessed for the 1996 Inventory (the
latest report available at the time of our review), as were 6 percent
of ocean and other shoreline waters. Pollution of the latter has
resulted in an increasing number of beach advisories and closures in
recent years.\3\
---------------------------------------------------------------------------
\3\ Water Quality: Key EPA and State Decisions Limited by
Inconsistent and Incomplete Data (GAO/RCED-00-54, Mar. 15, 2000).
---------------------------------------------------------------------------
Of 1,456 toxic chemicals we recently reviewed, data on
human exposure were being collected for only about 6 percent. For
example, of the 476 chemicals that EPA identified as most in need of
testing under the Toxic Substances Control Act, only 10, or 2 percent,
were being measured for human exposure. (See table 1.)
Table 1.--Extent to Which Human Exposure Data Are Collected for
Potentially Harmful Chemicals Through Surveys of EPA and the Department
of Health and Human Services
------------------------------------------------------------------------
Priority chemicals Chemicals measured
---------------------------------------------------- or being measured
No. in --------------------
Description of list list No. Percentage
------------------------------------------------------------------------
Chemicals found most often at the national 275 62 23
Superfund sites and of most potential
threat to human health...................
EPA's list of toxic of concern in air..... 168 27 16
Chemicals harmful because of their 368 52 14
persistence in the environment, tendency
to bioaccumulate in plant or animal
tissues, and toxicity....................
Pesticides of potential concern as listed 243 32 13
by EPA's Office of Pesticide Programs and
the U.S. Department of Agriculture's
Pesticide Data Program...................
Chemicals that are reported in the Toxic 579 50 9
Release Inventory; are considered toxic;
and are used, manufactured, treated,
transported, or released into the
environment..............................
Chemicals most in need of testing under 476 10 2
the Toxic Substances Control Act (Master
Testing List)............................
------------------------------------------------------------------------
Note: Our analysis was based on human exposure data collected through
the Department of Health and Human Services' National Health and
Nutrition Examination Survey or EPA's National Human Exposure
Assessment Pilot Surveys through 2000.
EPA has recognized that it has numerous and significant gaps in its
data and has initiated several efforts to fill at least some of the
gaps. For example, under its Environmental Monitoring and Assessment
Program, EPA is working with other Federal agencies to develop
information that the public, scientists, and the Congress can use to
evaluate the overall health of the Nation's ecological resources. EPA
also recently launched its High Production Volume Challenge Program,
which asked chemical companies to voluntarily generate data on the
effects of the chemicals they manufacture or import. As of December
1999, over 400 participants had agreed to make public, before the end
of 2005, basic hazard data on over 2,000 of 2,800 high-production-
volume chemicals, which are chemicals manufactured or imported into the
United States in amounts equal to or greater than one million pounds
per year. Furthermore, EPA's new information office will be responsible
for encouraging the agency's program offices to reach out to other
Federal agencies as well as to universities, research institutes, and
other sources of environmental information for data that EPA does not
collect but that may exist elsewhere. To date, however, such efforts
have been hampered by technological limitations imposed by the myriad
of incompatible information systems in use across the government.
Moreover, much of the information needed, such as environmental
monitoring data, will be expensive to obtain. Thus, it will be
important for EPA to work with the states and industry to reduce the
reporting burden and to encourage efforts to use data that may already
have been collected by other Federal agencies or other entities.
Likewise, as we recommended to EPA in our September 1999 report on its
information management activities, it will be essential for the agency
to develop a strategy that prioritizes its requirements for additional
data and identifies milestones and needed resources. EPA can then use
this information to support its budget requests.
Incompatible Data Systems Limit the Usefulness of Environmental Data
Over the years, EPA has developed and maintained ``stovepipe'' data
systems that are not capable of sharing the enormous amounts of data
gathered. EPA now recognizes that common data definitions and formats,
known as data standards, are essential to its efforts to integrate data
from various data bases, including those of its State partners. EPA
also considers data standards as key to reducing the reporting burden
on industry and the states because such standards would permit
integrated, and thus more efficient, reporting of information to the
agency. In recent years, EPA has undertaken several efforts to develop
standards for some of the data items in its information systems.
According to the Office of Environmental Information, EPA recently
approved six data standards and expects that all of these standards
will be implemented in the relevant data systems by fiscal year 2003.
EPA recognizes that its current data improvement efforts are only
first steps toward its goal of full data integration. For example, EPA
has focused primarily on the compatibility of its data with those of
State environmental agencies, rather than of other Federal agencies and
nongovernmental sources. In a May 2000 report, we stated that improved
collaboration among Federal agencies in meeting the needs for human
exposure data is essential because individual agencies have different
capacities and skills and separate attempts have fallen short of
supporting the large efforts that are needed.\4\ EPA's Science Advisory
Board\5\ has also recommended that EPA do more to link the agency's
data bases with external data bases. The Board noted that ``answering
many health-related questions frequently requires linking environmental
data with census, cancer or birth registry data, or other data systems
(such as water distribution maps) to determine whether there is a
relationship between the environmental measures and health.''\6\ EPA
officials acknowledge the importance of linking EPA's data bases with
those of other agencies at all levels of government. However, they told
us that their actions to do so have been limited by resource
constraints and by the fact that EPA's statutes do not give the agency
the authority to require that other agencies collect or report data
using formats compatible with those used by EPA.
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\4\ Toxic Chemicals: Long-Term Coordinated Strategy Needed to
Measure Exposures in Humans (GAO/HEHS-00-80, May 2, 2000).
\5\ The EPA Science Advisory Board was created by the Congress to
provide advice to EPA from scientists outside the agency.
\6\ Science Advisory Board, Review of the Agency-Wide Quality
Management Program, EPA-SAB-EEC-LTR-98-003 (Washington, D.C.: EPA, July
24, 1998).
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Concerns Persist About the Accuracy of EPA's Data
In various reviews, we and others have identified persistent
concerns about the accuracy of the data in many of EPA's information
systems. EPA acknowledges that data errors exist but believes that, in
the aggregate, its data are of sufficient quality to support its
programmatic and regulatory decisions. However, EPA has not assessed
the accuracy of its information systems agencywide, and preventing
errors and correcting them once they have been identified has proved
daunting for the agency. For example, in January 1998, an EPA advisory
council on information management issues described the difficulty of
correcting errors in EPA's data bases: ``Once an error is stored in one
or more of the agency's systems, making corrections to all those
systems is an exercise in frustration and futility. There is no simple
way to ensure corrections are made to all possible systems.''
To address such problems, EPA revised its agencywide quality system
in 1998 to expand and clarify requirements for how environmental data
are collected and managed. Although the Science Advisory Board recently
commended the agency for its development of this system, the Board also
found that its implementation has been uneven within the agency.
Moreover, the Board reported that more than 75 percent of the states
authorized to implement EPA's environmental programs lack approved
quality management plans for all or some of these programs and thus are
likely to be generating data of unknown quality. We recently reported
that EPA's National Water Quality Inventory, which EPA uses as a basis
for measuring progress under the Clean Water Act, does not accurately
describe water conditions nationwide. While EPA prepares the Inventory
on the basis of data submitted by the states, the states do not use a
statistical sampling design that provides a comprehensive picture of
water quality. The Science Advisory Board has pointed out that EPA
programs that rely on data of unknown quality are exposing themselves,
the reliability of their decisions, and their credibility to
criticisms.
Correcting errors in the agency's data is an important
responsibility for the new information office. This office recently
developed an Internet-based system to identify, track, and resolve
errors found in national environmental data bases. The system currently
allows individuals to notify EPA of suspected errors in some of the
agency's major data bases, and EPA intends to implement the data
correction system in additional data bases during the next 2 years.
efforts to develop outcome-oriented performance measures are
constrained by data limitations
Well-chosen environmental measures inform policymakers, the public,
and EPA managers about the condition of the environment and provide for
assessing the potential danger posed by pollution and contamination.
They also serve to monitor the extent to which EPA's programs
contribute to environmental improvement and can be used in future
priority-setting, planning, and budgeting decisions. EPA has been aware
of the need for environmental measures since the mid-1970's.
Nevertheless, the agency made little progress in developing such
measures until the Results Act mandated their use by requiring Federal
agencies to report annually on their progress in meeting performance
goals. Under the Results Act, EPA has begun to set goals and measures
that are intended to help the agency, as well as the Congress and the
public, assess the environmental results of the agency's activities.
While EPA has made progress in adopting more measures that reflect the
environmental or health outcomes of programs, the overwhelming number
of EPA's measures reflect outputs, such as the number of inspections
performed or regulations issued, and additional progress is needed.
EPA considers getting the data needed to measure results its
biggest challenge in developing outcome-oriented performance measures.
To date, EPA and the states have made limited progress in developing
such measures, as these examples indicate:
Of the 364 measures of performance that EPA has developed
for use during fiscal year 2000, only 69 (19 percent) are environmental
outcomes; the other measures reflect program activities, such as the
number of actions taken to enforce environmental laws. (See table 2)
Given inherent uncertainties about the results of research
and development activities, the problem of developing outcome-oriented
measures is particularly difficult for EPA's science activities. Of 36
measures related to EPA's strategic goal of ``sound science,'' only 2
reflect outcomes.
Table 2.--EPA's Analysis of the Number and Type of Annual Performance
Measures for Its Strategic Goals for Fiscal Year 2000
------------------------------------------------------------------------
No. of annual performance
measures
EPA's strategic goal --------------------------
Output Outcome Total
------------------------------------------------------------------------
Goal 1: Clean Air............................ 19 14 33
Goal 2: Clean and safe water................. 65 17 82
Goal 3: Safe food............................ 16 1 17
Goal 4: Preventing pollution and reducing 28 14 42
risk in communities, homes, workplaces, and
ecosystems..................................
Goal 5: Better waste management, restoration 34 8 42
of contaminated sites, and emergency
response....................................
Goal 6: Reduction of global and cross-border 27 7 34
environmental risks.........................
Goal 7: Expansion of Americans' right to know 28 3 31
about their environment.....................
Goal 8: Sound science, improved understanding 34 2 36
of environmental risk and greater innovation
to address environmental problems...........
Goal 9: A credible deterrent to pollution and 15 3 18
greater compliance with the law.............
Goal 10: Effective management................ 29 0 29
--------------------------
Total...................................... 295 69 364
------------------------------------------------------------------------
Source: GAO's analysis of EPA data.
In addition to establishing output- and outcome-oriented
performance measures, EPA has adopted a framework for categorizing its
performance measures according to the type of outputs or outcomes to be
achieved. As shown in figure 1, most of the performance measures are
outputs involving either research and development efforts or actions by
EPA, states, tribes, or other governmental bodies, such as establishing
standards for hazardous levels of lead in paint, dust, and soil. The
other categories represent outcomes, including measures that focus on
risks to ecology, health, or welfare; pollutants absorbed by the body;
and concentrations of pollutants in the environment. Over time, EPA
plans to increase the number of such measures, as it is able to obtain
better data linking its program activities with changes in
environmental and health conditions.
[GRAPHIC] [TIFF OMITTED] T1529.001
Even with better data, it will be a major challenge for EPA to link
its environmental programs and activities to outcomes. Environmental
conditions may change because of a number of factors, including
variables such as the weather or economic activity, many of which are
beyond the control of EPA and its State partners. Likewise, it may be
difficult to show the relationship between EPA's annual program
activities and some outcomes that may not be apparent until many years
later. For example, current EPA activities to reduce the amount of
polluting nutrients from fertilizers in the ground may not result in
improved water quality for a decade or more.
EPA program officials recognize that they need additional measures
that show the outcomes of programs, and they have recently taken
actions that should strengthen the agency's ability to develop them.
For example, EPA is developing processes and long-term strategies to
improve the quality of performance measures and link the activities of
program offices with environmental results. However, substantial
resources are required to identify and test the potential measures.
Once the measures are established, gathering and analyzing the data can
be resource-intensive, and it can take years to show environmental
improvement.
observations
Our prior work has identified numerous problems in the quality of
EPA's data and the way that the agency manages its data systems. These
problems cut across the various programs regulated by EPA and have
limited the agency's ability to assess risks and measure environmental
results. To its credit, EPA has initiated actions to improve its
information management activities. While EPA has made progress, its
initiatives do not provide a long-term strategy to ensure the
completeness, compatibility, and accuracy of its data. Furthermore, the
initiatives have encountered obstacles that highlight the difficulties
facing EPA as it attempts to improve its information management
activities.
As we recommended in our September 1999 report, to substantially
improve the quality of the data used to set risk-based priorities and
report on progress toward improving environmental conditions and human
health, EPA needs to develop a strategy that reflects a long-term
commitment to resolving data problems. Such a strategy should include
establishing milestones and identifying the resources necessary to fill
major data gaps, identify and develop all needed data standards and
implement them in key data bases, and coordinate the agency's data
standardization efforts with those of the states, Federal agencies, and
other organizations. This effort would provide both senior agency
managers and the Congress with what is now missing--the information
they need to make the best decisions possible on the costs, benefits,
and tradeoffs involved in providing scarce resources to meet critical
data requirements. Although EPA concurred with our recommendation, the
agency has made little progress toward developing and implementing a
comprehensive strategy. For example, EPA recently informed us that it
has not yet completed the first stage of a multi-phase effort to
develop an information plan for the agency. EPA plans to complete the
first stage by December 2000, which will identify broad options for
information management over the next several years.
Mr. Chairman, I would be happy to respond to any questions that you
or other members of the committee may have.
______
Responses by Peter Guerrero to Additional Questions from Senator Smith
Question 1. Please elaborate on how improved data and data
management can help EPA in developing cost-effective strategies to
reduce health and environmental risks?
Response. Scientific knowledge and technical information are
essential for determining which environmental problems pose important
risks to human health and the environment. This information is needed
to avoid wastefully targeting inconsequential problems while ignoring
greater risks. EPA also needs to be able to identify emerging and
future environmental problems and to have adequate data to develop
cost-effective solutions to those problems.
Question 2. What are some of the major obstacles confronting EPA
that preclude it from moving faster toward a results-oriented agency?
Response. EPA considers getting the data needed to measure results
its biggest challenge in developing results-oriented performance
measures. To date, EPA has made limited progress in developing such
measures. For example, of the 364 measures of performance that EPA
developed for use during fiscal year 2000, only 69 (19 percent) are
environmental outcomes; the other measures reflect program activities,
such as the number of actions taken to enforce environmental laws.
As we stated in our testimony, EPA is limited by gaps in
environmental and health data, data bases that do not operate
compatibly with one another, and the lack of an effective system for
ensuring the accuracy of the agency's data. Different data collection
and analysis methods among states (which EPA relies upon extensively
for information) make it difficult to aggregate data and use the
information to determine environmental outcomes. For example, states do
not use identical survey methods and criteria to assess water equality.
EPA officials told us that such inconsistencies from State to State
make developing national performance goals and measures for water
quality difficult.
Even with better data, it will be a major challenge for EPA to link
its environmental programs and activities to outcomes and move toward a
results-oriented agency. Environmental conditions may change because of
a number of factors including variables such ass the weather or
economic activity, many of which are beyond the control of EPA and its
State partners. Likewise, it may be difficult to show the relationship
between EPA's annual program activities and some outcomes that may not
be apparent until many years later. For example, current EPA activities
to reduce the amount of polluting nutrients from fertilizers in the
ground may not result in improved water quality for a decade or more.
Developing better information to characterize results will require
additional resources--to fill gaps, conduct monitoring on environmental
conditions, improve data management and quality, and so forth. Improved
cooperation among the many parties currently also involved in
collecting environmental data--states, tribes, local governments,
industry, other Federal agencies and the public--will also be
necessary.
Question 3. In its recently issued report on ``Strengthening
Science at the U.S. Environmental Protection Agency: Research
Management and Peer Review Practices (2000)'', the National Academy of
Sciences stated:
Scientific knowledge and technical information are essential
for determining which environmental problems pose important
risks to human health, ecosystems, the quality of life, and the
economy. We need scientific information to avoid wastefully
targeting inconsequential problems while ignoring greater
risks. We need such information to reduce uncertainties in
environmental decisionmaking and to help develop cost-effective
strategies to reduce risk. We need science to help identify
emerging and future environmental problems and to prepare for
the inevitable surprises.
Does GAO agree with the above statement? Please provide GAO's views
on what role should risk assessment and economic analysis have in EPA's
decisionmaking. What current attributes in EPA would need to be changed
to address the above issues?
Response. Recognizing the fundamental importance of good
information, both scientific and technical, GAO agrees with the above
statement and supports EPA's efforts to improve environmental
information. While both risk assessment and economic analysis are
important tools for EPA decisionmakers and should be used, they do not
provide precise answers to policy questions. This is because estimates
of health risks and economic costs are developed in the face of both
scientific uncertainties and data limitations, and inevitably include
assumptions and judgments.
Recognizing the limitations of both risk assessment and economic
analysis, we believe that EPA can nonetheless make improvements in how
it uses both tools in order to assist decisionmakers. The quality of
risk assessment is dependent upon the data available to perform the
assessment, which in the past have not been as complete as possible.
EPA's recent actions to reorganize information activities, develop a
comprehensive information plan, and implement various other information
initiatives are steps toward providing higher quality data needed to
improve the assessments. As we stated in our testimony, however,
successfully completing these data improvement actions will not be easy
and will require a long-term commitment and sufficient resources.
Likewise, EPA needs to take actions to make its economic analyses more
useful to both agency decisionmakers and the Congress. Chief among
these actions is improving the presentation and clarity of information
contained in the economic analyses, such as clearly identifying the
values of key assumptions as well as the sensitivity of benefit and
cost estimates to key data uncertainties.
Question 4. Your statement focused on data quality, availability,
and management problems. Are there specific recommendations you would
like to make for either the agency or the Congress in this regard?
Response. As we recommended last September, EPA's information
office should develop an action plan detailing the steps the agency
must take to ensure that its environmental and regulatory data are
sufficiently complete, compatible, and accurate to meet the agency's
needs.\1\ This plan should specify the resources that will be required
to accomplish these tasks. It should also lay out a strategy and
milestones for ensuring that EPA obtains the data it needs to
effectively set priorities, assess progress in achieving its goals and
objectives, and report on its accomplishments in a credible way. Such
an action plan would also serve the Congress in its funding decisions
and oversight of agency activities.
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\1\ Environmental Information: EPA is Taking Steps to Improve
Information Management, but Challenges Remain (GAO/RCED-99-261,
September 1999).
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In addition, Federal efforts to collect human exposure data are
very limited--largely because coordinated, long-term planning at the
Federal level has been lacking due to sporadic agency commitments to
human exposure measurement and monitoring. To help meet the gaps in
exposure data, we recommended that EPA work together with HHS and other
Federal agencies with environmental health responsibilities to forge a
strategic approach that would:
provide a long-term structure to human exposure monitoring
as an interagency effort,
establish a mechanism for setting priorities in line with
agency goals and performance measures,
clarify agency roles and minimize duplication, and
help agencies to share expertise.\2\
---------------------------------------------------------------------------
\2\ Toxic Chemicals: Long-Term Coordinated Strategy Needed to
Measure Exposures in Humans (GAO/HEHS-00-80, May 2000).
---------------------------------------------------------------------------
The Results Act, which requires agencies to coordinate their
research activities, also provides an existing mechanism for
congressional oversight over Federal efforts to more effectively
coordinate research. Continued congressional oversight of the Results
Act, with particular attention to this area, would be helpful.
Question 5. What is the status of EPA's use of benefit-cost
analyses in managing environmental risks?
Response. We have found that EPA and other agencies could make
improvements that would strengthen the clarity and credibility of their
economic analyses. For example, some of the economic analyses that GAO
reviewed did not incorporate the best practices set forth in OMB's
guidance (e.g., 5 of the 20 analyses reviewed did not discuss
alternatives to the proposed regulatory action).\3\
---------------------------------------------------------------------------
\3\ Regulatory Reform: Agencies Could Improve Development,
Documentation, and Clarity of Regulatory Economic Analyses (GAO/RCED-
98-142, May 1998).
---------------------------------------------------------------------------
Moreover, in our 1997 review of 23 economic analyses developed by
EPA in support of air quality regulations under the Clean Air Act, we
found that these analyses could be made; more useful by increasing
their clarity and thoroughness.\4\ For example, many of these benefit-
cost analyses did not include executive summaries, which can provide
easily accessible information for both agency decisionmakers and the
Congress. Some of the economic analyses did not identify one or more
key economic assumptions (such as the; discount rate or the dollar
value assigned to a human life) that can have a significant impact on
the results of the analysis. Furthermore, in the analyses that
identified key economic assumptions, the rationale for the values used
was not always explained. We recommended that the EPA Administrator
ensure that benefit-cost analyses identify the (1) value, or range of
values, assigned to key assumptions, along with the rationale for the
values selected, (2) sensitivity of benefit and cost estimates when
there are major sources of uncertainty, and (3) regulatory and non-
regulatory alternatives considered, including those not subjected to
benefit-cost analyses.
---------------------------------------------------------------------------
\4\ Air Pollution: Information Contained in EPA's Regulatory Impact
Analyses Can be Made Clearer (GAO/RCED-97-38, April 1997).
---------------------------------------------------------------------------
__________
Responses by Peter Guerrero to Additional Questions from Senator Baucus
Question 1. I appreciate your comments on the lack of environmental
data. This is a real problem. What is the recent history of EPA
requests for funding for environmental data collection and Congress'
appropriation of those requested funds?
Response. EPA does not have this information readily available.
However, the agency has assured us that it is currently gathering the
data needed to answer the question, and we will forward the agency's
response to you when we receive it.
Question 2. In testimony from later panels, we heard questions
being raised about whether risk assessments accurately predict harm to
public health, such as the incidence of certain types of disease which
may be caused by exposure to environmental contaminants. Is EPA or any
other Federal agency collecting national public health data of this
type so that more accurate national risk assessment work can be
performed?
Response. In our recent investigations into toxic chemicals and
indoor air pollution, we have found that the amount of data collected
was extremely limited. As we reported in May 2000, Federal and State
efforts to collect data on human exposure to toxic chemicals are
limited, despite some recent expansions due to improved technology.\5\
Surveys from EPA and the Department of Health and Human Services (HHS)
together measure in the general population only about 6 percent of the
more than 1,400 toxic chemicals that were included in our review. Even
for those chemicals that are measured, information is often
insufficient to identify smaller population groups at high risk, such
as children in inner cities and people living in polluted locations who
may have particularly high exposures. We found that three main barriers
limit Federal and State agencies' abilities to make more progress: (1)
Federal and State laboratories often lack the capacity to conduct
measurements needed to collect human exposure data, (2) there is often
a lack of information to help set test results in context, and (3)
coordinated, long-term planning among Federal agencies has been
lacking, partly because of sporadic agency commitments to do human
exposure measurement and monitoring. HHS and EPA officials indicated
that they have been discussing the merits of establishing a coordinated
interagency human exposure program, but they have not yet formalized or
agreed upon a long-term strategy.
---------------------------------------------------------------------------
\5\ Toxic Chemicals: Long-Term Coordinated Strategy Needed to
Measure Exposures in Humans (GAO/HEHS-00-80, May 2000).
---------------------------------------------------------------------------
In a separate review, we found that EPA is making progress in its
efforts to provide communities with more information on releases of
toxic chemicals, as required by section 312 of the Emergency Planning
and Community Right-to-Know Act (EPCRA).\6\ Thus far, public use of the
information has been limited. Much of the information has not been
computerized to provide easy access and when it has, it is not
available in regional or national data bases that permit comparisons
among industries or geographical areas. Further, EPA has not developed
policies, procedures, and standards to govern key aspects of its
projects to disseminate information or to assess the data's accuracy.
---------------------------------------------------------------------------
\6\ Environmental Information: Agencywide Policies and Procedures
Are Needed for EPA's Information Dissemination (GAO/RCED-98-245,
September 1998).
---------------------------------------------------------------------------
In our 1999 review of the status of Federal research activities on
indoor air pollution, we found that many gaps in knowledge and
understanding of the problem remain.\7\ These include gaps and
uncertainties with respect to (1) the identity and the sources of
pollutants, (2) the mechanisms by which people are exposed to them, (3)
the health effects resulting from prolonged and intermittent exposure
to low-level concentrations of chemical and biological pollutants as
well as complex pollutant mixtures, and (4) the most cost-effective
strategies for reducing pollutant sources, exposures, and consequent
health effects.
---------------------------------------------------------------------------
\7\ Indoor Pollution: Status of Federal Research Activities (GAO/
RCED-99-254, August 1999).
Question 3a. Clearly, EPA has an important role and a
responsibility in collecting environmental data. However, states too
have a role and responsibility in collecting these data. After all,
they have a considerable stake in protecting public health and the
environment. How much environmental data collection are the States
funding themselves?
Response. We have not independently compiled statistics on the
amount of data collection being funded by the states. However, a 1999
joint study by EPA and the Environmental Council of States (EGOS)
concludes that states are responsible for 83 to 99 percent of the
environmental pollutant data contained in six key EPA data systems.\8\
For example, more than 99 percent of EPA's air data comes from states;
about 91 percent of EPA's water data comes from states; and more than
92 percent of EPA's hazardous waste data comes from states. ECOS also
said that it is not necessarily the EPA demand for information that is
driving these State efforts. In many cases, states are attempting to
meet the demands of their own citizens and policymakers.
---------------------------------------------------------------------------
\8\ U.S. Environmental Protection Agency and Environmental Council
of States, Environmental Pollutant Reporting Data In EPA's National
Systems: Data Collection by State Agencies, Sept. 30, 1999.
---------------------------------------------------------------------------
EGOS reported that states were spending about $12.5 billion in
fiscal year 1996 (the latest date for which data is available) on
environmental protection and natural resources, with EPA providing
about $2.5 billion (20 percent) of this amount. EGOS does not have
specific information on how much of this is for data collection.
Question 3b. On their own, are states funding sufficient collection
of data for them to set risk-based priorities and develop results-
oriented measures of their environmental programs?
Response. We have not looked at this issue for all types of
environmental media. However, as noted in our testimony, we recently
performed a review of water quality data during which we surveyed all
50 states and the District of Columbia.\9\ All the states and the
District of Columbia responded to our survey. The results of our survey
highlighted the need for more comprehensive State monitoring and called
into question the extent to which unknown and potentially serious
problems are going undetected. Only six states reported having the
majority of the data needed to fully assess all their waters. Less than
half the states have a majority of the data needed to determine if
waters that have been assessed should be placed on their lists of
waters that do not meet standards.
---------------------------------------------------------------------------
\9\ Water Quality: Key EPA and State Decisions Limited by
Inconsistent and Incomplete Data (GAO/RCED-00-54, March 2000).
---------------------------------------------------------------------------
We also recently completed a review to determine the extent to
which State and Federal agencies--in particular the Department of
Health and Human Services (HHS) and EPA--collect human exposure data on
potentially harmful chemicals, including data to identify at-risk
populations.\10\ As mentioned earlier, the review showed that Federal
efforts to collect human exposure data are limited, measuring in the
general population only about 6 percent of the chemicals under review.
At the State level efforts were similarly limited: Almost all State
officials who we surveyed said they highly valued human exposure data
for populations within their borders. However, despite this perceived
value, most officials reported that they were unable to collect human
exposure data in most of the cases in which they thought it was
important to do so.
---------------------------------------------------------------------------
\10\ Toxic Chemicals: Long-Term Coordinated Strategy Needed to
Measure Exposures in Humans (GAO/HEHS-00-80, May 2000).
---------------------------------------------------------------------------
Furthermore, ECOS told us that, while states are generally
collecting the data they need to set risk-based priorities and develop
results-oriented measures, they may not have enough information to do
risk assessment. However, according to ECOS, it is clear that states
have had some success in collecting data needed for risk assessment,
based on the comparative risk projects undertaken in the 1990's and
used as input into Performance Partnership Agreements with EPA. A
number of states have also produced ``State of the Environment''
reports, which address environmental performance.
Question 3c. What is the correct mix between environmental data
collection funded by the Federal Government and that funded by the
States?
Response. We agree with the National Academy of Public
Administration's 1995 assessment that EPA should focus its activities
on problems of national, interstate, or intergenerational interest,
while supporting problem-solving at all levels through technical
assistance, increased flexibility, and information dissemination.\11\
The primary Federal responsibility should be to collect data to
identify overall trends and emerging issues, to determine risks
associated with exposure to harmful chemicals, and to fill the gaps in
existing data needed to set priorities and assess risks. The states, on
the other hand, must meet the demands of their own citizens and
policymakers while, at the same time, developing the information needed
to provide assurance that environmental laws are being properly
implemented and enforced.
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\11\ National Academy of Public Administration Report to Congress,
Setting Priorities, Getting Results: A New Direction for EPA, April
1995.
Question 3d. What, if any, State efforts are underway to
standardize environmental data collection to improve comparability and
public health protection?
Response. In a recent review on EPA's environmental information
management, we found that EPA and the states have taken initial steps
to increase data compatibility.\12\ As a part of the 1c398 action plan
for Reinventing Environmental Information (REI) initiative, EPA and the
states are developing six data standards to be used in 13 of EPA's
major data bases. The standards being developed will apply common
definitions and formats. According to the REI action plan, these six
standards will be developed, approved by EPA in partnership with the
states, and in use in the 13 designated data bases by the end of fiscal
year 2003.
---------------------------------------------------------------------------
\12\ Environmental Information: EPA Is Taking Steps to Improve
Information Management, but Challenges Remain (GAO/RCED-99-261,
September 1999).
---------------------------------------------------------------------------
The current initiative is limited in terms of the number of
standards being developed (six), the number of EPA data bases in which
the standards will initially be used (13), and the amount of data in
those data bases (only the new data being entered) that will
incorporate the standards. EPA recognizes that its current effort is
only a first step toward its goal of full data integration.
In response to the above question, ECOS emphasized that efforts are
currently underway to standardize data for the purposes of smoothing
the flow of data from states to EPA and sharing comparable data between
and among states. The Data Standards Council (a joint effort of states
and EPA) is leading the effort. ECOS cautioned, however, that the work
will improve the comparability of data, but will not eliminate it as a
problem.
EPA responded to the question by also describing the work of the
Data Standards Council and starting that the agency has also initiated
a new project in partnership with the states, the Information
Integration Initiative (I-3), this past fall. According to EPA, the
effort is an enterprise-wide approach to integrating, managing, and
providing access to environmental information. The agency will work
closely with the states and other data partners in developing this
comprehensive data exchange network. In its review of the fiscal year
2001 budget request, we found that while the concept of information
integration envisioned by EPA has merit, it is critical that the I-3
effort be well thought out, and that all prerequisite requirements be
met before embarking on this major investment. Many of the
prerequisites, in fact, had not been completed. The Subcommittee on VA,
HUD, and Independent Agencies, Senate Committee on Appropriations, also
questioned the requested funding for
I-3 in fiscal year 2001 beyond the amount needed to perform the
prerequisite steps for ensuring that the investment is prudent and the
project will be effectively managed.
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New Hampshire Comparative Risk Project,
Concord, NH, October 25, 2000.
Bob Smith, Chair and Max Baucus, Ranking Member,
Committee on Environment and Public Works,
U.S. Senate,
Washington, DC.
Attn: Angie Giancarlo
Re: NH Comparative Risk questions
Dear Senators Smith and Baucus: Thank you for your letter of
October 11 with follow-up questions to my October 3 testimony before
your Senate committee. In general, we agree wholeheartedly with Senator
Moynihan's observation at the October 3 hearing that environmental
management has ``matured'' over the past 30 years. We offer our
testimony, and the following comments, with that recognition, confident
progress can and will continue in this next generation of environmental
challenges.
Definitions: Before you read the enclosed answers, please review
the inside cover of the New Hampshire project guide, For Our Future,
where we define our goal as protecting ``environmental quality of
life,'' created by healthy people, healthy ecology, and healthy
economy.
Also, on page four of the guide, we define ``New Hampshire
Environment,'' ``comparative risk,'' ``risk assessment,'' and ``cost-
benefit analysis.'' In the answers below, ``comparative risk'' means
the collaborative, public, non-governmental process as used in New
Hampshire. Our process created a voluntary, public-private
partnership--participants identified hazards to our environmental
quality of life along a continuum, explicitly incorporating scientific
information, individual judgment, and personal values, using consistent
criteria, and a shared vocabulary regarding ``risk.'' Other states, and
USEPA in Unfinished Business, used a different, internally-based
comparative risk process, set within a State or Federal agency.
Traditional ``risk assessment'' is a very different undertaking, where
a specific individual risk is studied and the harm of exposure
quantified, often using models. We did not address the specific issue
of ``residual risk'' in the context discussed by others at the hearing.
__________
Statement of Katherine Hartnett, New Hampshire Comparative Risk Project
summary
(1) Thank you--for NEPA, CAA, CWA, SDWA, RCRA, CERCLA, SARA (1970-
1986) and reauthorizations. After 30 years, air, water, land are
cleaner, economy never stronger.
(2) Try to condense over 7 years of work into next 5 minutes (as
locals say, ``sugar down'').
(3) Fortunately, New Hampshire is small state--44th in area, 42nd
in population. The good news is, because of small scale, most effective
leaders try to work together (and it's ``hard to hide''). So, New
Hampshire is a good scale for an inclusive process.
(4) The process worked--55 stakeholders, from businesses,
environmental organizations, public health, citizen groups, political
leaders, and State and local government officials, gathered in an
neutral, non-advocacy setting to identify, study, and rank risks.
Technical staff summarized ecological, public health, and economic
information in consistent format, with consistent criteria. Group
worked by consensus, over 8 day-long sessions, to rank 55 risks to New
Hampshire environmental quality of life (``healthy people, ecology,
economy''). Documented influence of accessible science, personal
judgment, and individual values in ranking.
(5) Bottom line we began to separate fear from environmental
hazard, and now, to reduce hazard. While four of top ten risks were to
public health, four of top five were related to threats to air and
water quality. Traced risks back to 11 sources (i.e., transportation,
energy use, land use and development, recreation, water and food,
etc.). Identified four key actions to reduce hazard. Current focus on
two: (a) sound land use and (b) efficient use of energy, materials, and
resources.
(6) Identified transition to next generation of environmental
management, with changes from:
``Us vs. them'' to ``we''
``problems'' to ``opportunities'',
``illness'' to ``wellness'',
``economy vs. environment'' to ``economy = environment'',
``environmental threats to humans'' to ``Humans threaten
environmental quality''\1\
---------------------------------------------------------------------------
\1\NOTE: See attached outline and For Our Future: A Guide to Caring
for New Hampshire's Environment for more detail. For more info, pls
contact Katherine Hartnett, Exec Dir. kateharttiac.net
MESSAGE: Comparative risk process worked at NH scale. After 30
years of successful Federal and State environmental regulation, focused
on industrial and other point sources, we are now in a new generation
of environmental management (from ``us vs. them'' to ``collaboration'')
To continue success, we need additional tools, including fresh analysis
of environmental conditions and stressors, coupled with public/private
and federal/state partnerships, dynamic collaborations, effective
incentives, creative funding programs, and targeted education, along
with regulation and enforcement, to reduce current hazards and improve
overall quality of life.
---------------------------------------------------------------------------
(7) Stepping back, fits into evolution in New Hampshire, and U.S.,
in 20th into 21st century:
1920-1930's Conservation 1960-1990 Federal and State
Regulation 1990's Land Protection 215 century
Personal, Corporate, Public Responsibility
Summary
Comparative risk process worked at New Hampshire scale. After 30
years of successful Federal and State environmental regulation, focused
on industrial and other point sources, we are now in a new generation
of environmental management. To continue success, we need additional
tools, including fresh analysis of environmental conditions and
stressors, coupled with public/private and Federal/state partnerships,
dynamic collaborations, effective incentives, creative funding
programs, and targeted education, along with regulation and
enforcement, to reduce current hazards and improve overall quality of
life.
(1) Assumed points of agreement: Goal is to maximize environmental
protection, with minimal costs. By separating fear from hazard, it is
possible to more effectively prioritize actions Solutions that benefit
multiple problems are preferable. Design approaches that productively
engage multiple constituencies, and show results. Everyone has a role.
(2) New Hampshire experience: Designed credible, non-advocacy
process. Chose diverse participants that could: (a) leave
preconceptions at the door; (b) listen to others, and work
collaboratively; and (c ) bring a sense of humor to difficult
discussions. Put environmental quality of life at the center, comprised
of ``healthy people, healthy ecology, and healthy economy.'' Explicitly
evaluated hazards using science, judgment, and values. Created
continuum of hazards, used common vocabulary of criteria (severity,
extent, reversibility, uncertainty). Recognized long-term (7-10+ years)
nature of solutions.
How different * * * Unique features of New Hampshire's
Project: The New Hampshire project had the advantage of following
almost 20 other states through the comparative risk process.
Innovations unique to New Hampshire include:
Initial support and cooperation of state, private, and
non-profit participants.
Project housed at the neutral NH Charitable Foundation
(NHCF), rather than environmental regulatory agency, public health
agency, or State university.
Defined ``quality of life'' considerations to include
ecological, public health, and economic components, along with
individual values.
Focused on understanding and reducing hazard, with
commitment to developing and implementing focused actions, using an
integrated ranked list of risks to human health and ecological
integrity as a guide.
Used separate economic analysis to inform ranking and
priorities for action.
Public Advisory Group was very large (55 members), and
took 8 day-long meetings over 5 months to rank the 55 risks into an
integrated list that ``everyone could live with.''
Benefited from volunteer efforts of over 100 technical
experts in ecology, public health, and economics. Technical leaders
writing ecology, health, and economic reports received a stipend up to
$10,000 each, to ensure timely, accessible synthesis of information,
for ease of use by 55 members of Public Advisory Group. Used geographic
information system (GIS) for data analysis and presentation.
Created innovative ``quality of life'' model that allowed
individuals to explicitly identify their values influencing their
ranking.
Participated in concurrent ``collaborative assessment''
with independent technical experts experienced in supporting 30+ State
projects.
Identified action initiatives involving businesses, State
and local governments, environmental and public health groups,
educational institutions, and individuals.
Wrote thinnest final report, containing all technical
reports and ranking rationales.
Work continues on reducing hazard, in context of
Comparative Risk results.
How successful?: good process, educated participants,
contributed to decisionmaking such as:
NOX--recently announced Northeast Regional Ozone
Transport Assessment Group (OTAG) SIP call for ozone NH Clean Air
Strategy NH Climate Change Action Plan Lead in natural environment (in
sinkers, shot) Mercury (state strategy) Arsenic (program developing)
NHDES adding ``Resource Protection'' to strategic plan Environmental
organizations using study as technical reference and in organizational
strategy.
Also, Guide identifies 4 key actions to reduce hazard--specific
projects, such as Minimum Impact Development Partnership, Economy/
Environment Collaborative, and NH transportation strategy, implement
those actions.
How failed?: Sludge--could use comp risk process to evaluate
management options.
MTBE--huge focus, while arsenic management only slowly getting
underway.
(3) What was learned? Change takes time (7-10+ year process to move
to next generation of environmental management). Consistent, explicit
process built credibility. Useful information, and helpful perspective
for action by individual organizations. Knew from beginning that two
phases needed: (a) Separate fear from hazard; (b) Reduce hazard. Need
support for followup actions to reduce hazards.
(4) So what? NH actions to (a) Separate fear from hazard; and (b)
Reduce hazard:
Studied and ranked 55 risks, using science consistent
criteria, explicit judgment and values.
Traced 55 risks back to 11 sources, then 4 key actions.
New public/private partnership focusing on 2 key actions--
(a) sound land use and (b) efficient use of energy, resources,
materials--by developing voluntary practices for good development
(funded by USEPA Sustainable Dev. Challenge Grant). Also NHCF/McCabe
funded Economy/Environment Collaborative, working on economic drivers
to maintain NH Advantage of ``healthy people, healthy ecology, healthy
economy'' with ``virtuous'' cycle.
Using information, incentives, partnerships,
collaboration, good publicity, along with modifying existing
regulation, to implement.
(5) Comments to Congress/USEPA: Not certain on advice.
Do have some Q's: Is there a thought that there is a need to do
things differently, or continue with current process? Is the purpose
here to understand how to help Federal agencies be more effective?
Some ideas: Current set of environmental hazards not amenable to
legislation only--there's no single or suite of regulations alone that
will work in this generation of environmental management.
Why not take time to celebrate successes of first
generation of environmental hazards reduced? (after 20-30 years of
regulation, point sources clearly are much cleaner, and the economy
very productive--Congress can show the effectiveness of its laws).
Challenge today is even more difficult, because there are
no clear ``villains,'' or easy solutions everyone is involved, at work,
home, recreation; which is why information and clear understanding of
the issues are essential.
Acknowledge that managing next generation of hazards will
need new strategies rather than primarily a regulatory approach.
Possible actions:
(1) Claim success in regulating point sources. (2) Now need to take
the long view, and dedicate time to understand the problems. Let the
public know what you are doing, and why. (3) Convene annual hearings
for several years; ask for consistent information on regional and local
conditions. (4) Develop an action plan to support work of locals--
encourage community-based solutions informed with accessible data and
supported by sufficient funding.
In short, Federal role can be to stimulate require consistent
regional and local information about environmental conditions and
trends to assemble a national picture, and then support Federal, state,
local actions based on environmental data. Convene annual deliberations
that encourage results-oriented environmental quality--using
environmental indictors as measures of progress and linking agency
budgets to reducing impacts. Local citizens become involved, get
results, and see effects of Federal support on the ground, in their
communities.
______
Responses by Katherine Hartnett to Additional Questions from
Senator Smith
Question 1. New Hampshire has been a leader in the use of
Comparative Risk assessment. How have you used that method to become
more results-oriented?
Response. In essence, we were able to begin to separate fear from
hazard, and to focus on reducing hazard to our environmental quality of
life, defined as ``healthy people, healthy ecology, healthy economy.''
In New Hampshire, most hazards were traced back to how we use land and
energy/materials/resources.
The first generation of environmental management used ``command and
control'' to achieve results the main tools were ``end of the pipe''
regulation and enforcement to reduce releases of pollution to air,
water, and land (the individual ``environmental media''), through Clean
Air Act (CAA), Clean Water Act (CWA), Safe Drinking Water Act (SDWA),
Resource Conservation and Recovery Act (RCRA), ``Superfund''
legislation (CERCLA and SARA), etc., and to mitigate environmental
damage National Environmental Policy Act (NEPA). Examples of the
effectiveness in New Hampshire are summarized in the right-hand column
on page seven of For Our Future, and in left-hand column on page six.
The comparative risk process led us to recognize a transition into
the next generation of environmental management, where the sources are
many, the tools are varied, and everyone has a part. Our new model is
outlined below:
Today: People, Ecology, Economy--From ``Illness'' to ``Wellness''
------------------------------------------------------------------------
Illness Model Wellness Model
------------------------------------------------------------------------
1970-1980's,.............................. 1990-2000+
``Us'' vs. ``Them''....................... ``We''
Public health/economy vs. environment..... Integrated public,
ecological, economic health
Adversarial/Confrontation................. Collaboration
``Point'' sources (smokestacks, Many sources
wastepipes).
``End of pipe''........................... ``Upstream''
Remediation/mitigation.................... Prevention
Corporate Polluters....................... Efficient Producers and
Consumers
Regulation................................ Marketplace and Education,
along with Regulation
Air pollution control devices............. Energy efficiency/Demand
reduction
Diseases from environmental exposure...... Health through lifestyle
(diet, exercise, balance)
``What is the environment doing to us?''.. ``What are we doing to the
environment?''
------------------------------------------------------------------------
In New Hampshire, we used an inclusive, non-advocacy, science-based
process that involved all players to build credibility and visibility
needed to maintain an effort for the long-term (7-10+ years). Expanding
on my October testimony, specific results to date include:
NOx--recently announced Northeast Regional Ozone Transport
Assessment Group (OTAG) SIP call for ozone
NH Clean Air Strategy
NH Climate Change Action Plan
Lead in natural environment (in sinkers, shot)
Mercury (state strategy)
Arsenic (program developing)
NHDES added ``Resource Protection'' to strategic plan and
programming
Environmental organizations continuing to use study as
technical reference and in organizational strategy
receiving requests for copies the 1997 Report of Ranked
Environmental Risks in NH
hearing frequent reference to the study in a wide range of
meetings
In 1997-98, collaboration with NH Public Health
Association in their successful $1.1 million, 7 year ``Turning Point''
grant from WK Kellogg and RW Johnson Foundation (New Hampshire was one
of only 14 states nationally to receive funding).
In 1999, selection as one of 41 (of 650 applicants) to
receive a major national competitive USEPA Sustainable Development
Challenge Grant to work on reducing hazard through the Minimum Impact
Development Partnership ($117,438 over 3 years).
In the Spring 2000 session, key participation in the NH
Legislature study commission (HB 1390) directed to build on the work of
the NH Comparative Risk Project by improving public health and medical
practice to reduce environmental exposure.
In summary, the process allowed us to: (1) step back,
systematically evaluate current hazards using a process that explicitly
combined science, judgment, and values, and separated fear from hazard;
(2) establish that we had moved to the next generation of environmental
management, where we created a new model to describe our progress and
current situation; and (3) create wide range of initiatives to reduce
hazard (see page 26 of For Our Future).
Question 2. Has the NH Comparative Risk Assessment project had a
lasting impact on the public and on the other stakeholders?
Response. We focused on two audiences: (1) key decisionmakers and
(2) members of the public belonging to relevant constituency groups,
such as Business and Industry Association of NH, NH Public Health
Association, Audubon Society of NH, Society for the Protection of NH
Forests, and the NH legislature. Please see answer to question S-1
above for indication of effectiveness--we believe we have had lasting
impact on the perspectives of many key decisionmakers, and are making
progress on constituency groups. Because of the complexity of this
generation of environmental management, we had expected lasting impact
to take hold within 7-10 years (from 1994). As illustration, interest
in and support for Minimum Impact Development (MID) practices have
accelerated within the last year (see S-3 for more information on MID).
Question 3. How are you currently using the results of your
project?
Response. Following the rationale illustrated on pages 10-11 in For
Our Future, we are focused on encouraging sound land use practices, and
efficient use of energy, materials, and resources. Since 1997, all but
two of the projects listed in the right-hand column on page 26 of For
Our Future to reduce environmental hazard have been completed or at
least partially funded. Currently, as mentioned in my testimony
(Section 4 ``So What?'', at the top of page 3 of 3), our main
initiative is the Minimum Impact Development Partnership, a public/
private partnership to identify, define, and build ``good
development,'' that is energy efficient, protects habitat, and
minimizes pollution. Implementing minimum impact development should
reduce most of the 55 risk identified, especially those higher ranked
risks. Our strategy assumes maintenance of the current regulatory
system to continue to encourage reduction in pollution releases.
Question 4. Do you have any legislative suggestions to improve the
use of Comparative Risk Assessment in setting environmental priorities?
Response. As mentioned in the introductory paragraph, New Hampshire
used a collaborative, non-governmental partnership comparative risk
process model for our project, which we believe works best at a State
(NH), regional (Elizabeth River, VA), or local (Columbus OH) scale. We
defined our purpose as protecting environmental quality of life,
comprised of the combination of healthy people, healthy ecology, and
healthy economy. Another comparative risk approach is the inter- or
intra-agency model, used to directly address agency priorities (such as
described in USEPA's Unfinished Business or Science Advisory Board's
Reducing Risk, mentioned in the introductory paragraph and Senator
Baucus' Question #2 BACKGROUND).
Both approaches found widespread public recognition of the problems
perceived in the first generation of environmental risk. After thirty
years of progress and many successes, we found that we have moved into
a new set of challenges. For specifics on a process to identify and set
this next generation of environmental priorities, please see my
testimony, section (5) Comments to Congress/ USEPA on page 3 of 3.
Also, as I mentioned in my verbal testimony, three other Federal
initiatives are examples of next generation initiatives that help State
and local communities reduce environmental hazard associated with how
we use land and energy, materials, and resources: (1) Transportation
Equity Act (TEA-21) process and funding to diversify transportation
options into an integrated, connected, multi-modal convenient network
to reduce congestion; (2) USEPA's Sustainable Development Challenge
Grant program and (3) Conservation and Reinvestment Act (CARA).
______
Responses by Katherine Hartnett to Additional Questions from
Senator Baucus
Question 1a. The committee has heard a lot about ``good science''
and scientific ``uncertainty,'' but I see that the Project ranked
particulate matter, ground level ozone, and arsenic in drinking water
as among the highest risks in New Hampshire. There are some in Congress
who do not believe that the identification of these problems or the
estimation of their risks is based on ``sound science.'' Can you tell
me how your project dealt with scientific uncertainty in your project?
Response. At the project level, we recognized and accepted that
uncertainty is an inherent component of the scientific process, which
is why explicit judgment and values are so important in policy and
decisionmaking. Two examples illustrate the concept:
Smoking.--The epidemiology of lung cancer associated with smoking
has been known since the 1960's. The exact mechanism of the toxicology
was established only very recently. So ``scientific uncertainty''
created a generation-long debate over the effects of smoking on
smokers.
Particulate Matter.--Based on clear trends that showed increased
deaths and hospital admissions during periods with higher levels of
PM2.5, in the mid-1990's, USEPA moved to extend its
regulation to smaller particles, even though the causal mechanism was
unclear. A non-partisan expert panel recently independently replicated
EPA's results, with an analysis that confirmed the association between
elevated PM2.5 and excess mortality (see attached article
from SCIENCE, 4 Aug 2000, p. 711).
At the risk specific level, ``uncertainty'' was one of the four key
criteria evaluated and explicitly ranked, on a defined scale of 1-5, by
the ecological and public health technical work groups. The three other
criteria were ``severity,'' ``extent,'' and ``reversibility.''
Question 1b. Did you use conservative estimates, or apply
principles of precaution, in the face of uncertainty?
Response. We did both. Technical experts identified the ranges of
estimates; and stakeholders often injected principles of precaution on
their own. We also wrestled with the inherent conflict between low
severity high occurrence risks (such as chlorination by-products in
water supply or food additives and preservatives) and high severity low
occurrence risks (such as earthquakes or exposure to high level
radioactivity).
Question 1c. How were you able to reach the consensus with
stakeholders on ranking issues such as particulate matter, ground level
ozone, and arsenic in drinking water where there were scientific
uncertainties?
Response. Stakeholders were committed to ``getting something done''
and producing a ranked list of risks that would lead to risk reduction
by separating fear from hazard. We created a non-advocacy, accessible
science-based, iterative evaluation process, where everyone had their
say and all listened to other points of view. We all worked hard to
maintain a fair, unbiased, and credible process, to facilitate reaching
consensus, by first building trust among stakeholders. Each participant
increased their understanding of the nature of science, where
uncertainty is expected, and learned more about many controversial
issues. Everyone was dissatisfied, to at least some extent, with the
final ranked list a hallmark of a consensus-based work product. And
each always had the option of deciding ``I can't live with this''
result--which paradoxically, no one exercised. Additionally,
discussions incorporated evaluation of the uncertainty, severity,
extent, and reversibility associated with 55 risks to environmental
quality of life. Finally, and perhaps most importantly from the
perspective of participants, rationales for each risk ranking were
recorded in Chapter 6 of the 1997 report.
Question 2. I see that you used over 100 technical experts in a
number of sciences to review the environmental issues facing your
state. But in the end, you had a public advisory group--not the
technical experts--decide how to rank the risks of these issues. In
fact, based on your written testimony, which states that a risk ranking
was based on what ``everyone could live with,'' it seems these rankings
were negotiated. Can you explain why you used this approach rather than
basing the ranking solely on the work of the technical experts?
Response. Public perception shapes public policy. And as Congress
knows well, public policy is a subjective process, at best balancing
scientific evidence with individual belief, experience, values, and the
collective political process. The findings of technical experts alone
would have become just one more element competing for attention in the
larger process.
Our process started with a mix of public perception and expert
opinion on environmental hazard, incorporated scientific information
with consistent criteria, and then provided a forum for diverse
stakeholders to find the common ground ``that they could live with.''
Everyone participating changed some ideas based on new perspectives.
The ranking was rooted in science, and began an extended process of
public education to update that perception with new information about
the changing nature of environmental hazard.
PROCESS NOTE: The objectivity of the ranking process was
demonstrated in that participants stuck with a long and intricate
process--8-day-long meetings over 5 months. Participants arrived with
their initial rankings of a subset of risks, posted those rankings in
small groups, discussed their rationales, and reranked. The results of
the four small group rankings were aggregated, and mathematically
averaged, then discussed again as a large group. It was very
significant that rarely was even a slight adjustment to the aggregate
ranking considered, because the aggregate spanned the perspectives of
the group. Also, capturing the rationales for the ranking provided
context and illuminated the thought process.
BACKGROUND: The ranking was a product of late 1990's scientific
knowledge, judgment about that science, and individual values about
what matters most. In 1993 when the New Hampshire project began, public
perception of environmental risk had been formed by the images from the
1960' and 1970's--rivers on fire, polluting industrial smokestacks,
toxic wastes leaking out of illegally buried 55 gallon drums, etc. In
1987, in Unfinished Business, USEPA experts had ranked the most
pressing environmental risks of the late 1980's. In the follow-up 1990
report, Reducing Risk, USEPA's Science Advisory Board noted that the
risk list identified by agency experts was almost inverse to that
perceived by the public.
Question 3a. I'm impressed by the inclusiveness of your projects.
I'm sure that one of the big benefits was that the participants in
these projects developed a much better understanding of the risks posed
by various environmental issues. What about the benefits to the
understanding of the public at large?
Response. Thanks for your comment about inclusiveness; it was
important to us. Pls. see answer to Senator Smith's Question 2.
Question 3b. Have you actually studied whether the project has
changed public attitudes or, more generally, whether and what the
public-at-large learned from it?
Response. We have not had the time nor resources to study public
attitudes. Because of limited resources, we did not set out to
influence the public-at-large, but rather focus on two specific
audiences, as described in the answer to Senator Smith's Question 2.
Question 4. Could you give me examples of how the results of your
comparative risk project has influenced the budget, policies, and/or
activities of your State government?
Response. The New Hampshire project intentionally was designed to
involve all players who shape environmental policy--business,
environmental organizations, public health experts, citizen groups,
along with State and local government--because initiatives to improve
environmental quality of life will come from all sectors. Please see
answer to Senator Smith's Question 1.
Question 5. Has your comparative risk project changed the State's
priorities when it comes to how it interacts with, and what it requires
of, local governments in New Hampshire?
Response. Not yet. Changing how State government interacts with
local government is part of the work of the Minimum Impact Development
Partnership. The nature of what the State government can require of
local government is very limited in New Hampshire. Most importantly, we
intentionally designed our process to empower all citizens to act (see
pages 12-25 of For Our Future).
Question 6. What were the most important results of your
comparative risk project?
Response. Process: Please see answer to Senator Baucus' Question 1c
and Question 2 PROCESS. Outcome: Please see answer to Senator Smith's
Question 1.
Question 7. What were the keys to the success of your project?
Response. The process, which created a non-advocacy, neutral forum,
provided accessible science, with explicit technical criteria,
evaluated by judgment informed by belief and experience, and individual
values (more at Senator Baucus' Question 1c and Question 2 PROCESS).
Question 8. In implementing the comparative risk assessment, what
problems did you encounter that you could not, or could only partially,
overcome?
Response. Within the process, a number of participants felt
frustrated by the consensus-based nature of the final list, and so,
gave it less than full support. Also, one public health advocate
continued to believe that ecological risks shouldn't have been ranked
above those related to public health.
Additionally, some advocacy groups outside the process didn't
``buy-in'' on the results--for example, a small group opposed to land
application of biosolids (``sludge'') have succeeded in polarizing and
sensationalizing that issue, despite the relatively low risk ranking.
So those interested in ``single issue'' politics did not agree with a
process that built common ground, and placed risk in context.
Question 9. Do you think a comparative risk project similar to the
one done in New Hampshire could be performed on a national scale? Why
or why not?
Response. As described in the introductory paragraph and elsewhere,
there are at least two basic approaches to ranking risks along a
continuum of hazard (i.e., ``comparative risk''). In my written
testimony (section (2), page 1 of 3), I noted the key characteristics
of New Hampshire's public, non-governmental process--participants (1)
left preconceptions and vested interests at the door; (2) brought an
ability to listen to others and work collaboratively, and (3) had a
sense of humor to ease difficult discussions. If Congress or others can
create such a setting at the national scale, perhaps it might be
possible--depending on the purpose of the effort. USEPA met with some
success with the inter-agency process in 1987, and SAB in 1990 (as
noted in Senator Baucus' Question 2 BACKGROUND).
Question 10. In the panel on residual risk, many concerns were
expressed about EPA's case study residual risk assessment for secondary
lead smelters. This seems, in some ways, to be the nature of risk
assessments. In fact, it often seems that every time a risk assessment
is done these days--whether it is to regulate an environmental problem,
update a standard, or better understand a problem such as climate
change--it is greeted with an extremely high level of controversy.
Given this, how realistically do you think it is for us to consider
doing a comparative risk assessment that would set EPA's budget
priorities--something that would require a separate risk assessment for
each of the Nation's environmental problems--but still avoid
controversies over each and every risk assessment the priorities are
based on?
Response. As defined in the first paragraph on page 1, comparative
risk process is quite different from that of risk assessment.
Rather than using separate risk assessment, as outlined in
testimony on comments to Congress/EPA (page 3 of 3), we believe it is
time to move into the next generation of environmental management,
using new tools. National Science Foundation under Rita Colwell is
doing so, with their focus on ``biocomplexity'' as the key to effective
management in the 21st century.
However, if Congress were to choose to further explore the role of
national comparative risk process, much work has been done by the
National Academy of Public Administration. Congressional staff are
likely familiar with Setting Priorities, Getting Results (1995), a
clear articulation of the role of risk-based decisionmaking at USEPA. A
subsequent report, Resolving the Paradox of Environmental Protection
(1997), comes with an appendix tracking implementation of the 1995
recommendations at EPA. Their third report, Environment.Gov--
Transforming Environmental Protection for the 21st Century, is due out
next month, in November, 2000, with recommendations building on the
previous two. Resources for the Future also studied use of comparative
risk, in Worst Things First? (1994), and Comparing Environmental
Risks--Tools for Setting Government Priorities (1996).
Question 11. What should the states and the Federal Government be
doing to collect public health data that would help in performing
better risk assessments?
Response. Certainly, more data can help illuminate better
solutions. Data are most useful when: (a) collected based on a
strategic assessment of what we need to know to understand the
relationship between inputs and outcomes; (b) analyzed objectively
before decisions are made; and (c) reported consistently and regularly.
Use of data is an iterative process with making policy. An example:
USEPA initially regulated volatile organic compounds (VOC's) as a key
component in formation of ground level ozone (``smog''). Over many
years, additional data and analysis revealed that in New Hampshire,
nitrogen oxides (NOx) were the limiting factor. Only
recently have regulations been changed to incorporate the improved
scientific understanding of air pollution chemistry. Another example is
current focus on PM2.5 as a component in acid rain, ground
level ozone, and regional haze associated with the public health
outcome of excess urban mortality, ecological outcome of decreased soil
and forest productivity, and economic outcome of reduced visibility.
More generally, as outlined in our ``illness/wellness'' model,
public health and ecological health are interrelated; good data on the
both are needed, within a context that promotes health, rather than
catalogues extent of illness. As discussed in the previous paragraph,
``good data'' means relevant information, properly collected,
effectively analyzed, and consistently reported, in an iterative
process that modifies practices as understanding increases.
______
[From Science Magazine, Volume 289]
Air Pollution
panel backs epa and `six cities' study
(By Jocelyn Kaiser)
The Environmental Protection Agency (EPA) has won a major victory
in the fierce battle over its tough new standard for particulate air
pollution. Dealing a sharp blow to critics from industry, a nonpartisan
research group has reevaluated key data that EPA relied upon to set
that standard and has come out firmly behind the agency. Although all
scientific debate isn't over, the reanalysis ``puts to bed many of the
concerns that were raised'' 3 years ago, asserts John Vandenberg, an
EPA environmental scientist.
At issue was EPA's 1997 decision to extend its regulation from
particles 10 micrometers or less in size to those a mere 2.5
micrometers or less across (PM2.5). EPA based its decision
largely on two controversial studies that linked these tiny particles,
released mainly by motor vehicles and power plants, to higher death
rates.
In the Six Cities study, Harvard researchers examined the relation
between levels of PM and sulfates (a component of fine particles) and
death rates among more than 8,000 people in six U.S. cities, following
them for 14 to 16 years. The American Cancer Society (ACS) study
followed over 500,000 people in 154 cities for 8 years. Both found a
slight rise in death rates from health and lung disease in cities with
higher levels of PM2.5, although the mechanism remained
unclear. Based largely on the ACS death court, EPA calculated that the
benefits of cutting PM2.5 to 65 g/m3
over 24 hours would far outweigh the multibillion-dollar costs.
After EPA proposed the standard in 1996, the American Petroleum
Institute (API) and other industry groups blasted the two studies. Some
scientists also argued in congressional hearings that the apparent link
might result from other air pollutants, a less healthy lifestyle in
dirtier cities, or other confounding factors. Industry groups sued to
block the new regulations. A federal court decided that the science was
sound but threw out the rules based on legal arguments, which will be
heard by the Supreme Court this fall. At the same time, skeptical
industry groups and some lawmakers demanded that the Harvard
researchers turn over their raw data. The researchers refused, saying
that subjects' confidentiality would be breached.
To resolve the scientific and data-sharing issues, Harvard turned
to the nonprofit Health Effects Institute (HEI) in Cambridge,
Massachusetts. HEI assembled an expert panel to reanalyze both studies.
In a report released last week, that panel concluded that the
association between PM2.5 and excess mortality is real. The
team, led by statistician Daniel Krewski of the University of Ottawa,
replicated the studies from original data sets and got essentially the
same results: slightly higher death rates in the dirtier cities (see
table). The team probed the data for more than 30 possible confounders,
from altitude to health services, and tested the link ``in nearly every
possible manner'' with various analytical techniques. The results still
held.
ACS Six Cities
------------------------------------------------------------------------
Increased Death Rate
---------------------------------
Increase in PM2.5 across cities Original
Investigators Reanalysis
------------------------------------------------------------------------
18.6 g/m3.................... 1.26 1.28
24.5 g/m3.................... 1.17 1.18
------------------------------------------------------------------------
Confirmation. Reanalysis yielded results almost identical to the
original studies: a rise in death rate of 28 percent (in the Six
Cities study) and 18 percent (in the ACS study) from cleanest to most
polluted city.
Bill Frick, an attorney with the API, agrees that the reanalysis
has ``eliminated some of the uncertainty.'' Another major epidemiology
study released by HEI that looked at daily PM levels and deaths in 90
cities has also cleared up earlier doubts (Science, 7 July, p. 22). But
Frick argues that researchers still need to figure out which component
of PM2.5 causes harm and hence what problem needs to be
fixed--power plants or diesel trucks, for instance. A slew of new
federally-funded research is addressing those questions and will feed
into EPA's assessment of PM2.5 science this fall. Until EPA
decides whether to adjust the standard next year, it won't ask states
to comply with the regulations.
Meanwhile, the legal scuffle over access to research data
continues. In the wake of the controversy, Congress in 1998 passed a
law, sponsored by Senator Richard Shelby (R-AL), mandating the
federally-funded researchers release their raw data if requested under
the Freedom of Information Act. To the relief of scientific groups, the
White House interpreted the law narrowly, limiting it to grants awarded
after fall 1999 and only to data used to support regulations. The U.S.
Chamber of Commerce threatened to sue to broaden that interpretation
and began the process by filing requests last December for the Harvard
data. So far, EPA has refused to turn over the data because the study
predates the law. Keith Holman, an attorney with the Chamber of
Commerce, says the group hasn't yet decided whether to litigate the
case.
Statement of Michael J. Pompili, Assistant Health Commissioner,
Columbus Health Department
Good Morning Chairman Smith and members of the Committee on
Environment and Public Works. It is an honor to provide testimony to
you this morning particularly on a process which I believe strongly in
and which has been central to several programs which have been
developed for the Columbus community over the past 10 years. Your
willingness to discuss the use of comparative risk assessment in
setting community priorities demonstrates your understanding that there
are no simple answers to solving environmental issues that impact our
communities and that it is critical to involve stakeholders in the
process. During my next few minutes of testimony, it is my goal to
share with you how we have successfully implemented several comparative
risk processes in Columbus, Ohio, identify the central themes which
have led to the success of these efforts and to make recommendations to
you regarding the role of the Federal Government in such initiatives.
The Community Environmental Management Plan was established through
the Columbus Health Department, beginning in 1992. It is made up of
five components:
The Environmental Science Advisory Committee (ESAC) is a body of 18
environmental scientists, educators and other professionals who assist
city policymakers on a volunteer basis. ESAC is modeled after the US
EPA's Science Advisory Board. Its goal is to help leaders make better
decisions by offering advice, opinion and counsel on a wide range of
environmental issues.
Priorities 1995 is a classic example of a comparative risk
assessment. This innovative effort used over 250 community volunteers
to develop a comprehensive environmental blueprint for the city of
Columbus. Project participants logged more than 5,000 person-hours in a
2-year process that:
(1) Identified the City's most pressing environmental problems; (2)
Analyzed them to determine potential risk to citizens; (3) Ranked these
problems in terms of severity; and, (4) Developed potential solutions
to these problems.
Columbus' Environmental Snapshot uses key indicators to provide the
public with status and trend information on the State of the Columbus
and Franklin County environment. In creating the Snapshot, the
objective was to compile information already being collected by
numerous governmental organizations into a single, easy-to-understand
and user-friendly document. The information contained in the Snapshot
represents both an educational resource and a means of gauging the
success of past environmental efforts including a status report on the
progress of Priorities 1995 initiatives.
Columbus Community Risk Panel is a 35-member committee designed to
help Greater Columbus residents make informed decisions about risk. The
Panel, through various initiatives, serves as an ongoing resource to
help develop a more informed citizenry and provide the community with
accurate information on health and quality of life risks. Panel members
include public officials and other community leaders from government,
professional groups, public and private business, health care and
education organizations, and the media. A key goal of the panel is to
establish connections with citizens. This is accomplished through a
variety of projects including: the establishment of community computer
centers in inner-city churches, the Neighbor-to-Neighbor program,
formation of Community Advisory Panels that bring industrial facilities
and neighborhood groups together and establishing a web site for risk-
related information.
Project CLEAR is a new citizen-driven initiative based on the same
principles as our Priorities 1995 Risk Project. It is designed to
address Central Ohio outdoor air quality, particularly issues related
to ground-level ozone pollution. CLEAR's main objective is to involve
citizens, businesses, local governments, and other organizations in
evaluating and choosing strategies to improve air quality. What is
particularly unique about Project Clear is that it moves beyond public
opinion toward a public deliberation process.
Three basic principles underly all of the components of the
Community Environmental Management Plan: promoting the use of science
and scientific information whenever possible; developing a more
informed citizenry on issues of community health, environment and
quality of life; and encouraging public participation in the
decisionmaking process.
These principles have not only lead to the success for our efforts
but are appropriate at all levels of government: local, State and
Federal. An excellent example of these principles operationalized at
the State level was when Senator Voinovich, then Governor Voinovich
embarked on a comparative risk project for the State of Ohio. Similar
efforts have been conducted by 25 of the 50 states as well as at least
12 local communities. The process represents a new way of doing things
most importantly involving the public in meaningful ways on issues that
impact their lives.
So the question remains what role can the Federal Government play
in this effort. The Federal Government's role is to establish national
priorities. The use of a national comprehensive risk process could
provide general direction in setting these national priorities, but it
is very important to understand the limitations of a Federal
comparative risk project. A Federal comparative risk project is doomed
to fail if it means risks encountered in Florida are compared with
those found in Oregon. Instead it may be most appropriate for the
Federal Government to serve to support these efforts at the State and
local level and actively promote the principles of sound science,
informed citizenry and public participation in all environmental
initiatives. Specifically the Federal Government can serve as a
technical assistance center, both generating data and fulfilling the
role of information resource. States and local communities will vary
widely in their ability to successfully implement a comparative risk
process. Federal support and technical guidance may allow for at least
some degree of consistency and utility of effort. Because community
participation and buy-in are critical in these types of initiatives and
essential for any behavioral change to occur on the part of
individuals, Federal emphasis and support for community participation
at the local level may also be appropriate. Shifting from categorical
thinking formulas to community thinking formulas will go a long way
toward promoting involvement. Further, it may be helpful for states and
local communities to look to the Federal Government for funding of
comparative risk projects or at least linking to available funding for
such efforts.
Some of what I have described is not necessarily a new role. At one
time, the Federal Government funded a U.S. EPA office to directly
assist State and local folks interested in doing this type of work.
This Regional and Statistical Planning Branch of the Office of Policy,
Planning and Evaluation was extremely helpful to us in Columbus
providing a $50k grant for our project and direct technical assistance
in project formation and implementation. I have heard many other local
project directors share these sentiments. Unfortunately, the office was
disbanded a year or so ago and its personnel were re-assigned within
the agency. To my knowledge, there is now no Federal entity that exists
concerned with promoting and directly assisting State and local
governments with projects dealing with risk-based decisionmaking.
By recognizing the value of local communities in determining their
priorities, a further role for the Federal Government is flexibility.
While Federal standards and regulations are often warranted, it is
important to allow for some tailoring of effort according to a local
communities' need. US EPA's Project XL is a perfect example of this
type of philosophy. In its current form, however, Project XL is
somewhat cumbersome and a challenge to negotiate. We are quite pleased
to have just signed the final agreement for an XL project in Columbus,
an effort which took over 3 years to come to fruition.
In asking for this flexibility, however, local communities need to
hold themselves accountable and maintain the high, if not higher
standards than those set forth at the Federal level. If by your
flexibility at the Federal level you are demonstrating your trust of
State and local government to make sound environmental decisions, we
must safeguard this trust and work cooperatively with you toward common
goals. Without a certain level of trust at all levels of government,
even the most innovative programs are doomed to fail.
In closing, let me once again reiterate the importance of public
participation and connecting with our citizenry. More and more our
citizenry is expressing dissatisfaction or disinterest in civic
responsibility. While they are disengaging from the political process,
we must fight to have them actively involved in directing resources and
actions that will impact their own neighborhood and their quality of
life. We must demonstrate government's trust in the ability of
residents to make these programs work. I am a very strong believer that
our citizenry will make the ``right'' choices if they are able to
receive information in understandable ways, if they are presented with
accurate portrayals of existing tradeoffs regarding risk and if the
decisionmaking process reinforces the need to consider a full range of
options available. If these themes may be woven through the Federal,
State and local government, we may yet see a public which still seeks
out their civic roles.
Thank you for the opportunity to speak before you today.
______
Report--The Columbus Community Environmental Management Plan:
Protecting and Improving the Environment by: Using Science, Informing
Citizens, and Emphasizing Community Decisionmaking
the columbus environmental management plan
The Columbus Community Environmental Plan (CEMP) is designed to
protect and improve the area environment through three basic
principles:
Promoting the use of science and scientific information
whenever possible;
Developing a more-informed citizenry on issues of
community health, environment, and quality of life; and other issues
dealing with risk,
Using members of the community to help make risk decisions
where feasible.
The Community Environmental Management Plan is administered through
the Columbus Health Department, and has four basic components:
The Environmental Science Advisory Committee (ESAC)
ESAC is a body of 18 environmental scientists, educators and other
professionals who assist city policymakers on a volunteer basis. Its
goal is to help leaders make better decisions by offering advice,
opinion and counsel on a wide range of environmental issues. ESAC
considers and evaluates questions submitted by the Mayor, City Council,
Board of Health or City Department managers, focusing specifically on
the science behind environmental issues. Services can include client
meetings; document review, analysis and evaluation; property site
inspection and preparation of summary documents.
Priorities `95
This innovative effort used over 250 community volunteers to
develop a comprehensive environmental blueprint for the city of
Columbus. Project participants logged more than 5,000 man hours in a 2-
year process that:
(1) Identified the city's most pressing environmental problems;
(2) Analyzed them to determine potential risk to citizens;
(3) Ranked these problems in terms of severity; and,
(4) Developed potential solutions to these problems.
Columbus' Environmental Snapshot
This community document uses key indicators to provide the public
with status and trend information on the State of the Columbus and
Franklin County environment. In creating the Snapshot, the objective
was to compile information already being collected by numerous
governmental organizations into a single, easy-to-understand and user-
friendly document. The information contained in the Snapshot represents
both an educational resource and a means of gauging the success of past
environmental efforts.
Columbus' Community Risk Panel
This 35-member committee was formed in January 1998 to help ensure
that Greater Columbus residents are making informed decisions about
risk. The Panel, through various initiatives, serves as an ongoing
resource to help develop a more informed citizenry and provide the
community with accurate information on health and quality of life
risks. Panel members include public officials and other community
leaders from government, professional groups,. public and private
business, health care and education organizations, and the media.
environmental science advisory committee (esac)
ESAC is a body of 18 environmental scientists, educators and other
professionals who assist city policymakers on a volunteer basis. Its
goal is to help leaders make better decisions by offering advice,
opinion and counsel on a wide range of environmental issues.
ESAC considers and evaluates questions submitted by the Mayor, City
Council, Board of Health or City Department managers, focusing
specifically on the science behind environmental issues. The committees
resulting work products will differ according to the issue under
consideration. Services can include client meetings; document review,
analysis and evaluation; property site inspection and preparation of
summary documents. Because ESAC is an independent, volunteer
organization, it offers decisionmakers an objective (different)
perspective that can either confirm judgments or suggest new avenues of
thought.
Issues considered by ESAC include:
The possibility of health threats to police officers from
lead exposure at the police firing range.
An evaluation of City sewer line construction practices.
Watershed impacts from land application of manure from
area egg farm.
Review of Columbus noise ordinance.
Consideration of proposed uses for sewage sludge
incinerator ash.
Adequacy of a hazardous waste remediation plan for U.S.
Air Force property adjacent to Port Columbus International Airport.
priorities `95
This innovative effort used over 250 community volunteers to
develop a comprehensive environmental blueprint for the city of
Columbus. Project participants logged more than 5,000 man hours in a 2-
year process that:
(1) identified the city's most pressing environmental problems;
(2) analyzed them to determine potential risk to citizens;
(3) ranked these problems in terms of severity; and,
(4) developed potential solutions to these problems.
One of Priorities `95 greatest strengths was that it incorporated
both scientific information and public opinion in determining which
environmental problems are most serious and how these problems should
be addressed. Priorities `95 concluded with the development of almost
200 recommendations for environmental improvement.
Since the projects conclusion, the City has worked to address many
of the Priorities `95 recommendations. Notable efforts include:
Development of a parkland dedication ordinance in
conjunction with new residential development.
Development of a rabies public outreach/informational
campaign to increase pet vaccinations.
Acquisition of non-productive city properties for
redevelopment as community gardens, beautification projects or
neighborhood playgrounds.
Establishment of a 6-county coalition to address the issue
of atrazine runoff in the Scioto River watershed.
Development of a Recreation and Parks Department
containerized tree program that reduces growing time of planting stock
by over 50 percent.
the environmental snapshot
This community document uses key indicators to provide the public
with status and trend information on the State of the Columbus and
Franklin County environment. In creating the Snapshot, the objective
was to compile information already being collected by numerous
governmental organizations into a single, easy-to-understand and user-
friendly document.
A comprehensive community process was developed to select the 35
environmental indicators contained in the document. More than 40
governmental personnel, environmental scientists and members of the
general public served as advisors to select appropriate environmental
indicators. Their participation ensured that the most technically
relevant and easily understandable information would be used. Data is
presented for five environmental areas, and includes indicators for:
Urban Conditions.--Population; Platted Land; Building
Activity; Land in Farms, and more.
Air Quality.--Ambient Air Trends; County Vehicle
Emissions; Registered Passenger Vehicles; and more.
Drinking Water.--Finished Water Chemical Levels; County
Well Water Chemical Levels.
Surface Water.--Major Sources of Impairment; Fish Tissue
Analysis; and more.
Solid Waste.--Waste Generation, Reduction & Recycling;
Destination of Generated Tonnage; and more.
Over 250 copies of the report are distributed each year to
community groups, civic associations, community leaders and
individuals. The document is updated annually, an educational resource
that can help provide users with greater insight into the direction of
environmental trends and a means of gauging the success of past
environmental efforts.
columbus community risk panel
This 35-member committee was formed in January 1998 to help ensure
that Greater Columbus residents are making informed decisions about
risk. The Panel, through various initiatives, serves as an ongoing
resource to help develop a more informed citizenry and provide the
community with accurate information on health and quality of life
risks. Panel members include public officials; community leaders from
government agencies, professional groups, public and private business,
health care and education organizations; and the media.
Panel members meet quarterly, however activities of the panel are
ongoing. Current Community Risk Panel Projects include:
Development of Project CLEAR, a 2-year community
initiative designed to produce air pollution reduction strategies for
the Central Ohio area. The project will specifically examine issues and
strategies related to outdoor air quality, focusing on precursors to
ground level ozone formation.
Creation of Community Computer Centers, providing
computing sites with Internet hookup in inner-city areas. The programs
purpose is to provide health and environmental information to
populations that may not have computer access. The program is initially
focusing on establishing centers in African American churches to build
on the strong relationship that traditionally exists between these
churches and their congregations.
Neighbor to Neighbor, a community initiative bringing
people together to learn about specific things they can do to improve
their health, environment and quality of life. Neighborhood residents
form teams, which meet regularly with a trained leader in each others'
homes. With the help of a trained leader, the teams learn about simple
things that all of us can do to improve the health and environment, and
choose specific actions to help save energy, minimize waste or improve
health.
Creation of Community Advisory Panels (CAPs), an outreach
mechanism to bring neighborhood concerns to the attention of local
plant facility managers. The CAPs help citizens better understand how
facilities are working with hazardous materials onsite. Participants
meet regularly to discuss plant operations, facility environmental and
safety programs, etc.
______
Responses by Michael J. Pompili to Additional Questions from
Senator Smith
Question 1. You recommend that the Federal role be one of technical
and funding support to State and local agencies. You also recommend
that the Federal Government promote sound science and be more flexible.
In return, local and State agencies will be more accountable for
results. What specific recommendations do you have for the Congress?
Response. It is important that Congress spend more time on process
building instead of dealing with specific media issues. For example, I
have been actively involved with the U.S. EPA dioxin reassessment.
While having problems with specific parts of the assessment, the use of
the U.S. EPA's Science Advisory Board needs to be a very important part
of any review. Emphasis should be provided on supporting these
organizational mechanisms instead of specific reviews.
Shifting from the current categorical thinking model of addressing
a problem to a community involvement model would be a substantial step
forward. Because community participation and buy-in are critical,
components in solving the complex environment problems we face today,
it is important we change how we interact with our local citizenry. The
current Federal models are extremely deficient in this area, and need
to be examined in just about all phases of environmental legislation
such as the Resource Conservation Recovery Act, Superfund, Clean Air
Act Amendment, etc. We talk public hearings not public participation.
Emphasis is on exact levels of chemical contamination, not public
deliberation. Emphasis is on specific levels of testing not how the
different levels of government interact with their citizenry.
Question 2. Please describe the feedback you received from your
stakeholders during and following the Comparative Risk Assessment
Project?
Response. The main benefit that was achieved through the
implementation was the; building of trust and the strengthening of
relationships between the various stakeholders that exist within our
community.
Project stakeholders, regardless of their backgrounds or
qualifications, can generally be broken down into three general
categories:
(1) community volunteers who had no professional scientific or
environmental background,
(2) community volunteers who work in the research or environmental
arena, and
(3) city of Columbus department or division representatives.
All of the participants found the project challenging. The
necessity of group decisionmaking, the need to make decisions not only
on the basis of available technical information but also with
information on people's values, and the time required to carry out the
project were mentioned by most all participants as significant issues.
In addition, some participants were uncomfortable wrestling with
technical information.
However, by the end of the project, most of the participants
directly charged with analyzing, ranking and making risk-reduction
recommendations were grateful to have gone through the process. All
stated they had a much deeper understanding of the environmental issues
we studied, and more appreciation for the difficulties in setting
appropriate public policies. Our project chair, a former national
office-holder for the Sierra Club, stated he learned more about
environmental protection in the 2-years with our project than he had in
his adult lifetime as an environmental activist.
Some city of Columbus department or division representatives who
participated may have been most affected. Some of their comments
following the project spoke to their new ability to take many of the
concerns or ideas raised through the comparative risk process and work
with them on a daily basis. This type of continuity resulted in
implementation of a number project recommendations, and a general
growth in environmental awareness by some of the very people that are
in the best positions to improve the City's environmental protection
efforts.
One measure of satisfaction may be seen in that many participants
agreed, following the project, to form a new volunteer environmental
organization dedicated to helping city officials implement project
recommendations. The group has continued to function since its 1996
formation and presents annual awards to civic leaders for their
environmental efforts.
We have continued to buildupon this trust by following through on
the recommendations and also by reporting back to the community and our
participants on the status of their recommendations.
Finally, we have continued to work with our participating local
governmental bodies in working with them to implement the various
Priorities 1995 recommendations.
Question 3. What were some of the important lessons you and your
stakeholder's learned from the process and what would you do
differently if you had to do it all over again?
Response. First, the process, if done properly, does result in a
valuable environmental planning document and a group of participants
that are much more educated about environmental issues. It provides a
thorough and systematic way to simultaneously deal with a wide range of
environmental issues. It offers a significant way for the public to
help governmental decisionmakers craft environmental policy. It is
critical that in processes of this type, those that have the ability to
implement solutions play a significant role in the comparative risk
process.
At the same time, there are drawbacks to the comparative risk
process. It's lengthy and can be time-consuming. This can create a
problem for some people who may want to serve on a voluntary or short-
term basis. Also, getting the public actively engaged in an assessment
and planning process can be difficult. Meaningful public participation
is critical to the success of the process, but it's often difficult to
obtain in the absence of any environmental crisis or hot-button issue.
In addition, the lack of data or technical information on local
environmental problems can be a significant hurdle. Projects need to
gather as many technical resources as possible, both in terms of
suitable personnel and information. It is also important to understand
that the issue of using exact science was not really an issue. Our
participants, who actually gathered the information, had the
information reviewed by our Environmental Science Advisory Board. After
this reexamination, they reviewed the data, incorporated their values
and beliefs to achieve their final ranking.
Finally, there's a tendency for projects to spend the majority of
time assessing and ranking environmental problems. Project directors
must spend an equal amount of time and effort determining strategies
for implementing recommendations, creating new programs, etc.
Our process could be improved by: (1) streamlining the process so
that projects could be completed or repeated in less than the currently
required 2-year timeframe; (2) devoting more time and resources to
conducting a more-efficient public outreach campaign; (3) enlisting the
support of more environmental scientists/``technical experts'' to
gather the technical information and complete the technical analysis
portion of the project; and (4) spending considerably more time
planning; for the risk management portion of the project. We devoted
only about 30 percent of the total time to this portion of the project
our process.
Question 4. What are the key obstacles you face in setting
priorities and managing risk effectively at the local level?
Response. Substantial challenges are occurring at the local level
that are having significant impact on setting risk priorities and
managing risk effectively at the local level. They are as follows:
Information overload,
Complex issues,
Quick results desired, and
Limited budgets
Information Overload.--Every day our local citizenry is bombarded
with. ``important risk information'' that is being provided to assist
them in making informed choices. Currently this information is provided
in a condensed format and is often slanted toward a particular view.
Usually this information is provided in a manner that has dueling
experts who have totally opposite views and use terms that are foreign
to everyone but the experts.
Additionally people now have access to the Internet which opens a
whole new myriad of issues.
With the Internet an abundance of information is now available with
the vast majority being non peer reviewed and slanted to a particular
agenda. This is an issue that will exist for the foreseeable future and
I do not think this problem has an easy solution.
Complex Issues.--The easy fixes have been achieved. The issues
before us now are complex because they incorporate beliefs and values
that require substantial tradeoffs and usually have volumes of
conflicting information available to support all sides of an issue.
This is why I consistently go back to working on a deliberative process
of public involvement and deliberation before an issue is addressed.
Quick Results.--Our public and therefore our elected officials want
quick actions and are less patient to wait for the long term
sustainability that is desired with most of. our current issues.
Limited Budgets.--As with our local governmental actions, the
limited amount of financial resources forces the priorization of
resources. This is an area where the Federal Government can be very
helpful. In a large amount of situations it would be very beneficial if
the Federal Government could provide seed money to demonstrate the
value of citizen involvement and participation in local priority
settings.
If these initiatives were successful then there is a far better
chance that these initiatives will be carried on because of the low
relative costs compared to the potential large benefits.
______
Responses by Michael J. Pompili to Additional Questions from
Senator Baucus
Question 1a. I note that one of the outgrowths of your project is a
focus on ground level ozone--an environmental problem that some here in
Congress believe does not require more stringent regulation because
that would not be based on ``sound science.'' Can you tell me how your
project dealt with scientific uncertainty in your project?
Response. The goal of Project CLEAR is to recommend strategies to
reduce emissions that contribute to formation of ground-level ozone in
Central Ohio. The project will develop these recommendations through a
combination of public involvement through civic forums and objective
analyses by several technical working groups. Project CLEAR is a
partnership of the Columbus Health Department, The Ohio State
University, and the Mid-Ohio Regional Planning Commission. Stakeholders
from business, government, non-profit organizations, and universities
are represented and involved.
Two factors led to the initiation of this project. The first is the
possibility that Central Ohio will violate existing Federal EPA ozone
standards or certainty that our region will violate the proposed
Federal standard for ozone. The second is concern among some
stakeholders about the health threats posed by ozone.
CHD and other Project CLEAR partners are aware that ``scientific
uncertainty'' exists around the nature and extent of health effects
from exposure to ground level ozone.
Having or facilitating a scientific and/or political debate about
the ozone standard is beyond the scope of Project CLEAR. Nor is trying
to rank the ``problem'' of ground level ozone among other health and
environmental concerns facing our region. In local government, we must
comply with Federal and State mandates and enforcement actions. It is
important to understand that, fundamentally, the purpose of Project
CLEAR is to take a proactive approach toward the standards and the
possibility that central Ohio may find itself in violation of it. This
fundamental purpose requires us to educate and involve our community
and undertake analyses of emission reduction potential of various
strategies. While the larger debate is interesting and important, it is
not germane to the fundamental purpose of this project.
The project partners selected Dr. Paul Berkman, an Earth Scientist
at the Byrd Polar Research Center at The Ohio State University (OSU),
as Chairman of Project CLEAR. In 1997, Dr. Berkman convened a national
symposium. on ground-level ozone at OSU. The symposium brought together
experts from industry, government and various perspectives within the
scientific and health community for a balanced program on this issue.
Dr. Berkman has worked diligently to ensure scientific objectivity in
Project CLEAR.
Project CLEAR has established a scientific working group that is to
provide general scientific oversight to the project.
(2) The Project CLEAR Steering Committee includes representatives
from industry, government, non-profit groups, and many others.
(3) Project CLEAR provides information from a wide variety of
sources to stakeholder participants and interested members of the
public. These sources are linked on the project web site and in other
written materials.
(4) Project CLEAR has developed an ``issue guide'' concerning
ground-level ozone in Central Ohio. Several representatives from
industry, government, environmental organizations and others worked
together to develop the guide. (We have enclosed a copy.)
Question 1b. Did you use conservative estimates, or apply
principles of precaution, in the face of uncertainty?
Response. This question is not applicable to the main objectives of
Project CLEAR.
Question 1c. How were you able to reach the consensus with
stakeholders on ranking issues such as ground level ozone where there
were scientific uncertainties?
Response. (1) Project CLEAR is not designed to undertake a process
to rank environmental issues. Please see the overview for a more
complete explanation; (2) The Project CLEAR Steering Committee will
recommend strategies to reduce ozone-forming emissions by the end of
2001. These recommendations will be made by consensus and will be based
on cost, ability to implement, emission reduction impact, according to
analyses of technical working groups. They also will be based on public
involvement featuring up to 20 deliberative issue forums from fall of
2000 through early summer of 2001.
Question 2. I see from your written testimony that two of your
prime emphases were science and community-based decisionmaking. Some
would see these two as inconsistent, since the general public brings
their experiences, judgments, and values ``to the table'' whereas
science is ostensibly objective. (a) Can you explain how science and
community-based decisionmaking were melded in your comparative risk
project? (b) Please explain why you chose to have the public make
ranking and priority decisions rather than simply relying on the work
of the technical experts.
Response. My first point would be that it is a misconception to
think that science is ``objective.'' In many areas, there are honest
disagreements among scientists as to the extent and severity of an
environmental problem, the ``correct'' meaning or interpretation of
data, etc. In making their conclusions, scientists themselves use their
own values and opinions as a filter through which they look at data and
information.
This is no different than what the non-scientific public does in
making decisions. The information all of us consider is filtered
through our own individual values and opinions. The advantage that the
scientist may have is simply that he or she may have access to and
knowledge of more information. The strength of the comparative risk
process is that it strives to gather all of the relevant scientific
information possible and then get it into the hands of project
participants for consideration. Linking the concepts of science and
community decisionmaking together is not inconsistent, it simply means
that the public should have the benefit of knowing and considering all
of the relevant information--that the public should have the
opportunity to make the most informed choice possible.
We attempted to meld these ideas in our project in a number of
ways. First, our technical committee (i.e., our ``scientists'') wrote
environmental analyses based on the scientific information available,
their own knowledge and ''experiences, etc. These analyses were
forwarded to the project's management team for their review. In
addition, the analyses were summarized, distributed to members of the
general public for comment end discussed at a community open-house.
All comments from if he general public concerning the technical
reports were documented and submitted to the project management team.
The project management team considered both information contained in
the technical analyses and the public feedback from those analyses to
rank our 30 environmental issues in terms of severity.
The public, in fact, did not do the project risk ranking . . . it
considered the information produced by the project's technical
committees, commented on their findings, and their comments were passed
to the project management committee for its ranking. We specifically
chose not to give ranking responsibilities solely to the technical
experts because we felt that the project's success hinged on buy-in
from the public. Leaving the ranking solely in the hands of ``technical
experts'' would hurt our credibility and leave I,us open for public
criticism, ultimately damaging; our ability to develop project
recommendations that the public would support.
Lawmakers make laws in much the same way . . . they rely on
technical experts to provide scientific information, but they realize
that the public will not accept policies crafted solely by these
experts. They use community feedback, as well as their own values and
opinions, to develop appropriate laws, policies and procedures.
It must be stressed that even though our project ranking (i.e.,
``priority decisions'') was done by a project management committee and
not the general public, the public's values and opinions played a
significant role in the ranking outcome. The project management
committee built an explicit mechanism into the ranking procedure to
reflect public input on the scientific findings of the technical
committees. Individual ranking decisions could be adjusted based on (1)
the level of feeling that the public may have registered about a
particular environmental issue, and/or (2) whether a particular group
is disproportionately impacted by a specific environmental issue. In
numerous instances, project management committee rankings were
subsequently adjusted to reflect; information gathered from the public.
Question 3a. I'm impressed by the inclusiveness of your project.
I'm sure that one of the big benefits was that the participants in
these projects developed a much better understanding of the risks posed
by various environmental issues. What about, the benefits to the
understanding of the public at large?
Response. The Priorities `95 Comparative Risk Project was our
attempt to involve the public in setting our communities environmental
priorities. Community participation and buy-in are critical components
in solving the complex environmental problems we face today. To that
end we utilized many various outreach mechanisms to reach our public.
These outreach mechanisms included:
Public Opinion Surveys;
Community Meetings;
Distribution of educational materials;
Community-wide Open House; and
Media events
As we continue down this path with our CLEAR program, we are
further expanding our community outreach efforts to include public
deliberation sessions in many parts of the central Ohio community.
Benefits to understanding of public at large:
As previously explained, even with our substantial
community outreach, vast pockets of the public still are uninformed
about the process. The areas where the most substantial impacts were
achieved were with our State and local (city and county) elected
officials and the environmental community.
I do not want to imply that all environmental groups were pleased
with the process, since specific environmental groups elected not to
participate, but overall the response was positive and this success has
now led to our CLEAR program.
Question 3b. Have you actually studied whether the projects have
changed public attitudes or, more generally, whether and what the
public-at-large learned from it?
Response. Studied whether changes in public attitude have occurred:
Concerning the studying of public attitudes, we have not
formally conducted a public attitudes survey. The main reason, as
always, was the lack of funding to perform the surveys. We are trying
to perform a more thorough review within the CLEAR program as we are
working with the Ohio State University, but again that will be
dependent on resources. Additional, we want to critically review the
advantage of using a public deliberative process instead of the current
public hearing process.
Question 4. Could you give me some examples of how the results of
your comparative risk project have influenced the budget, policies,
and/or activities of your local and State government?
Response. A number of City department or division representatives
actively participated on our comparative risk project committees;
working to analyze environmental issues, gauge the public's response to
various technical reports, and evaluate implementation alternatives.
Since the project's conclusion, these representatives have returned to
their City positions and have been able to work with many of the
project issues and concerns in the normal course of their employment.
This has resulted in a number of initiatives being implemented in
direct or indirect response to comparative risk recommendations. The
City can point to a number of specific achievements since the project's
conclusion. Among them:
The creation of a Natural Resource Manager position within
the Columbus Recreation and Parks Department to oversee and coordinate
issues concerning department parkland and park habitat.
Current City efforts in modifying the Mid-Ohio Regional
Planning Commission's Watercourse Protection Ordinance, for eventual
submission to Columbus City Council for approval. The ordinance
addresses a number of recommendations concerning green space and
habitat protection.
Development of a Stormwater Master Planning Review to
review stormwater design criteria and policies so that the natural
conditions of ravines, creeks, rivers, meadows, woodlands and wetlands
can be preserved or restored if possible.
Creation of new city code requirements detailing
additional requirements for provision of sidewalks when subdividing
land, and increasing the Public Service Director's ability to require
sidewalks in new developments or enlargements. The work is in
addresssing a Priorities `95 recommendation to construct walkways to
improve access or reduce walking distances for pedestrians.
The launch of the Stay Tobacco-free Athlete Mentoring
Program (S.T.A.M.P.) pilot. The program matches high school athlete
mentors with sixth-grade; students in an effort to discuss issues
relating to tobacco use and encourage participants to remain tobacco-
free. The effort addresses a recommendation to encourage school and
community-based programs on the effect of smoking.
Adoption of a Parkland Dedication Ordinance, which
providers for the dedication of parkland as part of the re-zoning
process for residential and non-residential projects of more than one
acre. This ordinance, jointly developed by the departments of Trade and
Department and Recreation and Parks, addressed a recommendation calling
for green-space set-asides in connection with new development.
The Department of Recreation and Parks receiving a
community award for adopting a containerized tree growing process that
reduces growing time of planting stock from 7 to 3 years. This has
allowed the department to grow more of its own trees, and select
particular species, rather than rely on what is available from
commercial growers. The city is now growing 5,000 trees annually in
efforts to fill 45,000-50,000 vacant right-of-way locations. Plantings
will improve aesthetics, neighborhood cooling and reduce storm water
runoff. This effort addresses a Priorities `95 recommendation to plant
native shrubs and plants whenever feasible.
The Department of Recreation and Parks assisting the Mid-
Ohio Regional Planning Commission in forming a number of citizen river
stewardship groups. One of the project recommendations advocates the
City encourage creation of Citizen Watch Groups to monitor activities
that may adversely impact area waterway corridors.
Efforts by the Division of Refuse Collection to initiate
recycling programs at Columbus apartment complexes. Priorities `95 had
recommended that the City encourage development of a pickup system for
department recyclables.
Development of the Neighborhood Quality Interaction Team
program, a community-based initiative that consolidates and better
coordinates city inspection services among the departments of Health,
Refuse, Trade and Development and Police. The pilot office is located
in the Franklinton area. Plans are to duplicate the initiative in other
City neighborhoods. The effort is in response to an Priorities `95
recommendation to develop neighborhood programs to improve zoning and
health code enforcement.
Establishment of an Urban Pet and Wildlife Management
coalition to address a variety of pet and wildlife issues. The
coalition; developed by the Columbus Health Department, published a
comprehensive report outlining a number of recommended actions to
address urban animal problems. The report, and anticipated ongoing
efforts by the coalition, address a Priorities `95 recommendation to
develop a community outreach program and a public information campaign
on rabies.
Establishment of a 6-county coalition to address the issue
of atrazine in the Scioto watershed. The Division of Water helped form
this coalition, consisting of representatives from the city of
Columbus, Ohio Department of Natural Resources, Ohio EPA, private
industry, area farmers, OSU Extension Service, Ohio Wesleyan University
and Otterbein College. The partnership is identifying potential
pollution sources, conduct field sampling, monitor the watershed and
develop an action plan for reducing atrazine use and resulting
pollution. The coalition's work addresses a Priorities 1995
recommendation to convene the agricultural, scientific and regulated
communities to develop a chemical management plan for Central Ohio
watersheds.
Question 5. What were the most important results of your
comparative risk project?
Response. The main benefit that was achieved through the
implementation was the building of trust and the strengthening of
relationships between the various stakeholders that exist within our
community.
Project stakeholders, regardless of their backgrounds or
qualifications, can generally be broken down into three general
categories:
community volunteers who had no professional scientific or
environmental background,
community volunteers who work in the research or
environmental arena, and
city of Columbus department or division representatives.
All of the participants found the project challenging. The
necessity of group decisionmaking, the need to make decisions not only
on the basis of available technical information but also with
information on people's values, and the time required to carry out the
project were mentioned by most all participants as significant issues.
In addition, some participants were uncomfortable wrestling with
technical information.
However, by the end of the project, most of the participants
directly charged with analyzing, ranking and making risk-reduction
recommendations were grateful to have gone through the process. All
stated they had a much deeper understanding of the environmental issues
we studied, and more appreciation for the difficulties in setting
appropriate public policies. Our project chair, a former national
officeholder for the Sierra Club, stated he learned more about
environmental protection in the 2-years with our project than he had in
his adult lifetime as an environmental activist.
Some city of Columbus department or division representatives who
participated may have been most affected. Some of their comments
following the project spoke to their new ability to take many of the
concerns or ideas raised through the comparative risk process and work
with them on a daily basis. This type of continuity resulted in
implementation of a number project recommendations, and a general
growth in environmental awareness by some of the very people that are
in the best positions to improve the City's environmental protection
efforts.
One measure of satisfaction may be seen in that many participants
agreed, following the project, to form a new volunteer environmental
organization dedicated to helping city officials implement project
recommendations. The group has continued to function since its 199Ei
formation and presents annual awards to civic leaders for their
environmental efforts.
We have continued to buildupon this trust by following through on
the recommendations and also by reporting back to the community and our
participants on the status of their recommendations.
Question 6. What were the keys to the success of your project?
Response. Two factors were critical in the success of our project.
The first was the appointment of our project chair. Because of the
complexity and length of the comparative risk process, it is essential
that these projects be manned by an individual who:
has credibility with other project members concerning
their environmental knowledge and experience.
is perceived among project participants as ``fair,'' or
neutral, concerning the airing/balancing of different environmental
philosophies and goals that are part of these projects.
is committed to public input and public participation
regarding the process.
will devote the significant amount of time required over
the 2 years to assist with project management, task delegation and
followup, etc.
is personally committed to the success of the project.
Unless the project chair can meet each of these criteria, a
comparative risk projects faces considerable handicaps in successfully
achieving its goals.
The second critical factor was the inclusion of key city of
Columbus personnel in the project . . . particularly in the
implementation phase. Project organizers recognized that any City
implementation efforts would only be realized if city of Columbus
personnel were intimately aware of the project and supported its
eventual recommendations. To ensure that this happened, they made a
conscious effort to build this into to project by recruiting some City
staff, mid- and upper-level management personnel to participate. As a
result, these participants had knowledge and input concerning the
potential project recommendations, their implementation feasibility and
creation of initiatives or programming that would meet the
recommendations' intent.
Question 7. In implementing the comparative risk assessment, what
problems did you encounter that you could not, or could only partially,
overcome?
Response. Generating significant public knowledge, awareness and
excitement about the project was a challenge. Our public involvement
committee was forced to be rather creative at times concerning our
public outreach efforts. In a city the size of Columbus, with all of
the various initiatives competing for the public's (and the media's)
attention, this may have been the most difficult aspect of the project.
We would have liked a greater level of public involvement from the
community.
Question 8. I appreciate your recommendation that Federal supports
are provided so more communities like yours can do their own
comparative risk projects and set their own priorities. But putting
this aside, do you think a comparative risk project similar to the one
done in Columbus could be performed on a national scale and be used to
establish budget priorities for the Agency?
Response. The main role of the Federal Government in environmental
protection is to provide leadership and direction in meeting our
national environmental priorities. Therefore, it is very important that
a general direction be provided for insuring the overall protection of
our Nations' air, water and lands. What is at issue is not that this is
a noble goal, but how as a Nation we desire to reach these goals.
One of the hardest things for us to learn with our Priorities `95
project was to give up control; to trust our citizenry within their
specific neighborhoods that they would make the ``correct'' decisions
for the betterment of the greater Columbus community. Well they did!
Yes, we had pet projects, specific contentious issues, etc.; but
overall they looked at the bigger picture. This is the fundamental
issue that has to be addressed by the Federal Government.
Does the Federal Government trust states and local governments with
providing meaningful input into setting our national goals? My answer
is that this can be achieved through a process of inclusion and openess
that needs to be directed within the various regions of the country.
Will it be difficult--yes, will it be beneficial--definitely--if it is
done correctly. Could it be a disaster--yes, if it is controlled too
much by Washington, DC.
I strongly encourage the examination of performing a national
environmental priority comparative risk project, but only with
significant involvement with governmental stake;holders on the
national, State and local levels.
Question 9. In the panel on residual risk, many concerns were
expressed about EPA's case study of residual risk assessment for
secondary lead smelters. This seems, in some ways, to be the nature of
risk assessments. In fact, it often seems that every time a risk
assessment is done these days--whether it is to regulate an
environmental problem, update a standard, or better understand a
problem such as climate change--it is greeted with an extremely high
level of controversy.
Given this, how realistic do you think it is for us to consider
doing a comparative risk assessment that would set EPA's budget
priorities--something that would require a separate risk assessment for
each of the Nation's environmental problems--but still avoid
controversies over each and every risk assessment that the priorities
are based on?
Response. Any risk assessment work will produce some level of
controversy. One reason is the nature of the task--the impossibility,
because of uncertainties, of absolutely defining the level and
likelihood of hazard to people, or groups of people, from an
environmental threat. Risk scenarios are all based to some degree on
assumptions--assumptions that are open to honest debate or disagreement
among individuals, whether they are scientists, members of the
regulated community, or the general public. Risk assessment work,
particularly in the area of comparative risk, implies to many that
winners and losers will be created as the result of the process. Those
associated with a ``high-risk'' issue will probably support the process
and results. Others concerned with ``low-risk'' issues may question or
dispute the process out of fear it would de-legitimize their concerns.
But the fact that comparative risk cannot eliminate controversy
should not be used as an argument against using the process. By
comparing the severity of one problem against another, the process does
forces participants to do something that each do daily in our everyday
lives--make choices and evaluate various alternatives based on the
information we have available. Decisions cannot be made in a vacuum.
Actions and choices have impacts that must be considered before
decisions are made. The comparative risk process recognizes this in its
attempt to consider environmental problems in the context of other
problems, and in its attempt to make these decisions using all
available information.
In a sense, every organization that puts together a budget uses a
type of comparative risk process. The budget process is nothing more
than a systematic assessment determining the level of funding that will
be attached to each of an organization's various functions, programs or
activities. In part, this assessment is made by considering the
importance of activities, and the impact of carrying them out relative
to other possible budget choices. Agency budgeting using the principles
of comparative risk would be nothing more than a formal recognition of
this fact. Such a process would simply be a systematic assessment of
environmental problems using defined criteria to determine the levels
of risk resulting these problems. Potential criteria could include the
number of people affected, severity of effect, reversibility of effect,
level of uncertainty, disproportionate populations affected, etc. There
would certainly not be unanimous agreement about the budgeted funding
levels resulting from this type of assessment. However, a systematic
analysis using this type of criteria to determine the EPA priorities
would certainly be a step in the right direction.
Question 10. You indicated that the Federal Government could be
doing a better job of providing funds and more accurate data to the
states so they can do more comprehensive comparative risk assessments.
What, if any, efforts are the states undertaking to improve the
comparability and standardization of the data that they collect? What
public health data do Ohio or other states provide as part of the
Federal-State partnership?
Response. Unfortunately, I have very little knowledge within this
area. This question would be far more appropriate for Katherine
Hartnell of the New Hampshire Comparative Risk Project.
__________
Statement of J. Clarence (Terry) Davies, Senior Fellow, Resources
for the Future
I am pleased and honored to be able to share with the committee my
views on the important subject of comparative risk assessment. My views
are only that and do not represent the institutional position of
Resources for the Future (RFF). RFF is a research institution that does
not take positions on policy issues.
Comparative risk assessment (CRA) is an important analytical tool
that deserves the attention this committee is giving it. The
fundamental goal of most of our environmental programs is to reduce or
prevent risk. Thus, identifying and comparing risks is a logical
starting point for evaluating progress and identifying future
directions and priorities.
There are, however, important limitations inherent in the use of
CRA. Most importantly, we have no common metric to deal with the many
diverse kinds of risk that government addresses. When I was at EPA we
referred to this as the ``how many whales is your grandmother worth''
problem. How do we weigh the risk of pesticide poisoning of trout
streams to the risk of causing cancer in humans? How do we compare the
risk of cancer to the risk of long-term neurological damage? How do we
compare one type of cancer to another?
There are answers that can be given to these questions, but the
answers are heavily dependent on values. Even if scientific
understanding were perfect and data were complete and accurate, the
value elements inherent in CRA would prevent CRA from ever being a
purely scientific undertaking. The science and the data in most cases
are woefully incomplete, and this adds further elements of uncertainty
and value judgment to CRA.
different types of cra
There are different kinds of CRA, and some distinctions are
important. In particular, there is a basic difference between comparing
individual pollutants or activities and comparing programs. Comparing
mercury to lead is very different from comparing air pollution to water
pollution. This hearing is focusing primarily on the latter, on
programmatic CRA, and it's important to keep this in mind.
More generally, the type of CRA undertaken, and the process used to
make the comparisons, should depend on the purpose for which the CRA is
being done. Doing a CRA to establish research priorities involves
different considerations than CRA to establish enforcement priorities.
uses of cra
CRA serves a variety of different purposes. Among the more
important:
CRA serves to focus people on the question of what are the
benefits of a program or action, what are we getting for the resources
expended. In this sense, CRA and the Government Performance and Results
Act (GPRA) serve the same beneficial purpose.
CRA can be a starting point for setting budgetary and
other priorities. In a recent evaluation of pollution control efforts
in the United States, I questioned whether EPA priorities were in line
with risk considerations, given that most of the risks identified as
highest in CRA analyses ranked lowest in EPA budget expenditures.
However, such comparisons of risk rankings to budget expenditures are
useful only in a broad sense. There are other important factors, aside
from risk, that should and do enter into budgetary priorities.
CRA can serve to identify neglected problems. Indoor radon
is a good example of a problem where analyzing the risks highlighted an
environmental problem that was receiving little attention. David
Konisky at RFF has recently completed an analysis of all the CRA
efforts undertaken to date in the United States, and his analysis shows
how some neglected problems have surfaced. With your permission, I
would like to submit this paper for the record.
CRA, like all good analysis, can make the assumptions
behind decisions more transparent. These may be assumptions as to why
something was not done as well as to why something was. We all know the
very high risk of cigarette smoking. Documenting the high risk
encourages us to ask why more action is not taken and what alternative
courses of action are available.
CRA helps to identify needed data. Very often, in the
process of asking about relative risks, we discover we do not have the
data necessary to answer the question. For example, of the 80-100,000
chemicals in commercial use, we have adequate toxicity information
about only a few hundred.
CRA can catalyze and mobilize opinion so that action can
be taken. CRA, especially at the State or local level, can be a way of
getting people to agree on an agenda for action and then to act.
Arguably, most of the recent State CRAs have been as much about
political mobilization as about risk analysis.
limitations of cra
As I noted at the beginning of my testimony, the assumptions and
values that unavoidably enter into both risk assessment and CRA are a
major consideration. Risk assessment is an odd mixture of science and
non-science, and CRA necessarily suffers from all of the limitation of
risk assessment.
CRA suffers from additional methodological problems. For example,
how should the risk-reduction effect of current efforts be considered?
If there were no public programs to protect drinking water in this
country, drinking water would rank among the highest risks, as it does
in many developing countries. However, because there are protection
programs, the current risks from drinking water in the United States
are not great. In the context of budgeting, for example, this poses
difficulties for CRA. We cannot do zero-based budgeting if the analysis
of risks assumes current levels of spending.
Most importantly, CRA deals only with risk, and risk is only one of
several factors that should enter into most government decisions. Cost
is an obvious other factor. To the extent that decisions should be
based on cost-benefit analysis, risk gives only the benefit side of the
equation. Furthermore, you cannot do a cost-benefit analysis of a
problem, only of a solution. Whereas CRA deals with problems, cost-
benefit deals with solutions. So getting from one type of analysis to
the other is not simple because the two types of analysis are analyzing
two different sets of things.
Aside from risks and costs, public decisionmakers need to consider
such things as due process, administrative feasibility, legality, and
political support. No one has yet developed an analytical method for
putting together all these factors.
Two other limitations of CRA should be noted. First, how the CRA is
done can have an important effect on its outcome. Konisky's paper shows
that how broadly the categories are defined (e.g. particular pollutants
vs. outdoor air pollution vs. all air pollution) can make a big
difference in the resulting risk ranking. Second, how and when to
involve the public in the process poses a variety of questions. The
value aspects of CRA mean that the public should play a key role.
However, this raises problems of how to incorporate technical and
scientific information. Granger Morgan at Carnegie-Mellon University
and others are conducting interesting experiments on this question.
the statutory context
Congress has given EPA only limited flexibility. With approximately
1,000 pages of legally binding guidance, there are only a few choices
left to the Air Office, for example. No amount of analysis will change
the basic agenda of EPA, which is set by the environmental statutes.
Many, arguably most, provisions of EPA's laws are not based on
risk. For example, most of the standards in the Clean Water Act are
technology-based standards, so analysis of risk is, at least in theory,
irrelevant to setting these standards. Even where Congress has employed
risk-based standard setting, as with the National Ambient Air Quality
Standards (NAAQS), the scientific basis is sometimes deficient or
outdated. The statutory language on NAAQS assumes a risk threshold (a
level below which there is no risk) whereas we have understood for more
than a decade that there is no threshold for most of the criteria
pollutants. It is difficult to use good science to make decisions if
the relevant statutory provisions do not allow good science to be used.
The fragmented, medium-based (air, water, soil) nature of the
pollution control laws, programs, and budgets also hinders the use of
CRA. Most risks cut across media lines, so the scientific data about
risk does not follow the budgetary or program categories. The risks of
arsenic are within the purview of the air office, the water office, and
the office of solid waste. Nitrogen poses risks in air, water, and
soil. Climate change is an air problem, a water problem, and a land
problem. The United States is one of the last industrialized countries
to cling to a non-integrated pollution control system, and difficulty
in using risk information is one of the penalties we pay.
conclusions
Despite its limitations, CRA is a valuable analytical tool. It may
be most useful for the questions it raises and as a way of initiating a
process leading to more transparent and defensible decisionmaking. How
well it serves these functions will depend heavily on whether Congress
itself asks for relevant risk information and uses the answers in its
budgetary, oversight, and legislative actions.
______
Responses by J. Clarence (Terry) Davies to Additional Questions from
Senator Smith
Question 1. You provided some of the benefits of conducting
``comparative risk assessments''. You also stated how the science and
the data in most cases are woefully incomplete. Please explain how Risk
Managers at EPA or at the States or Municipalities could improve their
performance of risk management if they had a better understanding of
type and magnitude of risk they are dealing with.
Response. A better understanding of the type and magnitude of risk
would enable managers to focus on the most important problems in the
most efficient way. Conversely, it would enable them to avoid wasting
resources on minor or non-existent risks, including the critical
resource of public attention and concern.
Question 2. You stated that comparative risk assessment is a tool
that helps us take the first step in managing risk effectively by
defining the problem. You also testified that we need to go beyond
defining and ranking the problem. You stated that we need to focus also
on solutions. Please describe the tools available to risk managers for
identifying alternative risk reduction strategies and the criteria for
selecting the right programs.
Response. Identifying alternative risk reduction strategies is not
straightforward, and I am not aware of any good analytical tools to
assist in the process. In reality, such strategies are usually based on
legislative mandates, and the mandates are usually based on strategies
that have been tried in other contexts. The most basic criterion for
selection is, in my view, cost-benefit analysis broadly defined. By
broadly defined, I mean that non-quantitative factors must be included
in the selection process.
Question 3. Please provide your recommendation on how to proceed
from here to achieve more effective environmental programs.
Response. As I indicated in my testimony, I think two of the most
important steps would be legislative creation of a Bureau of
Environmental Statistics and enactment of an integrated pollution
control statute. My version of the latter includes the former.
______
Responses by J. Clarence (Terry) Davies to Additional Questions from
Senator Baucus
Question 1. You stated in your testimony that comparative risk
assessment can be a ``starting point'' for setting budgetary and other
priorities. You go on to say that comparisons of risk rankings to
budget priorities are useful only in a ``broad sense.'' Please explain
further what you mean by these comments.
Response. CRA is only a starting point because a number of other
important factors must be considered in priority-setting. These other
factors include cost, equity, legislative and judicial requirement,
administrative and political feasibility.
Question 2. Since it is basic to risk assessment, what is the
appropriate way for the committee to decide when the science used in
them is ``good science'' or not?
Response. There is no foolproof way to evaluate the science used.
Whether the science has been peer-reviewed and whether it has been
published in a reputable journal are the usual criteria, and I do not
know of better ones.
Question 3. Clearly, science is needed to inform decisionmaking.
But what, in your opinion, is the proper role of nonscientific
considerations, such as societal values, in informing decisions on the
risk rankings and priorities that are developed from comparative risk
assessment?
Response. Non-scientific considerations are important and
unavoidable. See my response to Question No. 1. Also, consider that
science, by definition, can never tell us what should be, only what is.
Question 4. In the panel on residual risk, many concerns were
expressed about EPA's case study residual risk assessment for secondary
lead smelters. This seems, in some ways, to be the nature of risk
assessments. In fact, it often seems that every time a risk assessment
is done these days--whether it is to regulate an environmental problem,
update a standard, or better understand a problem such as climate
change--it is greeted with an extremely high level of controversy.
Given this, how realistic do you think it is for us to consider
doing a comparative risk assessment that would set EPA's budget
priorities--something that would require a separate risk assessment for
each of the Nation's environmental problems--but still avoid
controversies over each and every risk assessment the priorities are
based on?
Response. I do not think that it would be realistic to do a CRA
that would, by itself, set EPA's budget priorities, but for the reasons
stated above and in my testimony, not because of controversy. There is
always some controversy about science, and much of the conflict over
EPA science is really a conflict over interests and values rather than
over science.
Question 5. I would be interested in your thoughts on what problems
would likely be encountered, and how successful we would likely be, if
we attempted to perform a national comparative risk assessment in order
to set EPA's budget priorities.
Response. In Chapter 2 of Comparing Environmental Risks, a 1996
book which I edited, I try to describe some problems and choices that
are faced by all CRA efforts. How to define the categories to be ranked
and how to involve the public are probably the two most difficult
problems that would be encountered. Overall, I would not be very
optimistic about the success of such an effort.
Question 6. You mentioned that the Nation should have a Bureau of
Environmental Statistics. As you may recall, such a proposed
independent Bureau was part of legislation in the 101st Congress (S.
2006) but faced significant opposition. Now, the Pew Commission on
Environmental Health has proposed a national system for collecting data
on public health through the Department of Health and Human Services
and States. The committee could benefit from any views you may have on
this latest proposal, if you have the opportunity to review it.
Response. I have not had a chance to review the Pew proposal.
However, the proposal relates to data on human health, not to data on
the natural environment.
__________
Statement of Elizabeth L. Anderson, President and CEO,
Sciences International, Inc.
My name is Elizabeth L. Anderson. I am president and CEO of
Sciences International, Inc., (Sciences) a consulting firm
headquartered in Alexandria, VA, that specializes in providing support
to the public and private sectors on health and environmental issues.
Previously, I was director of the first Carcinogen Assessment Group
(CAG) and the expanded Office of Health and Environmental Assessment
(now the National Center for Environmental Assessment) at the U.S.
Environmental Protection Agency (EPA). I established and directed the
Agency's central risk assessment program for 10 years, and was
executive director of the Committee that recommended adopting risk
assessment and risk management as EPA's approach for regulating
carcinogens and later other toxicants. The Committee also wrote the
Agency's first risk assessment guidelines. I represented EPA on
numerous interagency committees. I am also a founder and past president
of the Society for Risk Analysis and am currently Editor-in-Chief of
Risk Analysis: An International Journal, which is published bimonthly
by the Society and serves as an international focal point for new
developments in risk analysis for scientists of all relevant
disciplines.
I frequently serve as a peer reviewer for governmental
organizations on issues dealing with risk assessment. For example, I
recently served as a peer reviewer for the South Carolina Department of
Health of the document Assessment and Recommendations for the South
Carolina Air Toxics Standard; I am a member of the External Review
Committee, Los Alamos National Laboratory; I chaired the External
Review Committee, United States Department of Agriculture's Office of
Risk Assessment and Cost-Benefit Analysis; and I served on the Board of
Scientific Counselors, Committee to Review EPA's National Health and
Environmental Effects Research Laboratory. I currently serve on a
National Academy of Sciences/National Research Council Committee and am
a peer reviewer for the Academy. A copy of my Resume is attached.
purpose of this testimony
Although Sciences is involved in a wide range of risk assessment
issues and investigations, a focus of the research and analysis work
conducted by me and my colleagues at Sciences is improvement in the
sciences that support human health and environmental exposure and risk
assessments, such as those conducted today as part of EPA's comparative
risk assessments and the hazardous air pollutant (HAP) residual risk
program. A major need in comparative risk assessment is development and
use of scientifically supported methods and data to identify and
appropriately address areas of most important environmental risk. This
need is evident most recently in EPA's mandated HAP residual risk
program which involves an unprecedented use of risk assessment and is
being required while the science of risk assessment is still very much
in flux. In that program, over 175 industry categories subject to
maximum achievable control technology (MACT) standards currently being
developed must have residual risk assessments completed to serve as the
basis for risk management decisions. These risk assessments are
required 8 years after promulgation of each MACT standard and will in
total involve emissions of the 188 HAPs from literally thousands of
facilities. The risks must also be estimated for all types of climates
and terrains, wide ranges of population distributions, direct and
indirect (i.e., multipathway) exposures, human and ecological effects,
and consideration of maximum individual as well as total population
risk. This would be an extremely difficult and challenging task for any
risk assessment program.
My purpose today is to provide my thoughts on the direction and
progress of the use of risk assessment by EPA and what actions might be
taken that would make that use more effective and more soundly based in
science and, thus, more responsive to our Nation's needs. My analysis
is based largely on two important recent documents which describe how
EPA is currently intending to apply risk assessment. The first is the
Residual Risk Report to Congress (Report No. EPA-453/R-99-001), which
was published in March 1999 and provided the Agency's broad scientific
guidelines for managing that program. The second is EPA's first draft
residual risk assessment document which was released for Science
Advisory Board (SAB) review in January of this year. It provides the
first detailed application of the guidance from the Report to Congress
for performing residual risk assessments, and was applied in a case
study to the secondary lead smelting industry.
Let me briefly describe the comparative risk and residual risk
assessment programs and their goals. Then I will identify a number of
issues that make risk assessment complex and implementation of these
programs exceedingly difficult. Finally, I will offer several
recommendations for improving the risk assessment process.
comparative risk assessment
Comparative risk assessment is broadly the process whereby human
health and environmental risks are identified and evaluated and the
risks compared to assist in setting priorities and in making informed
regulatory decisions. At the core of the process must be sound risk
assessment science and stakeholder participation to provide the
necessary framework for sound and socially responsible decisionmaking.
Comparative risk assessments typically look at all types of risks in
all environmental media and seek to provide sufficient information to
make appropriately informed decisions. These decisions must necessarily
rely on the identification and use of accurate risk assessment methods
and data.
epa's residual risk regulatory program
Risk assessment is currently being used in EPA's residual risk
regulatory program. The 1970 Clean Air Act Amendments first required
the EPA to identify and then regulate HAPs to levels that provide an
``ample margin of safety to protect the human health.'' The term
``ample margin of safety'' was defined by EPA in 1989, after the U.S.
Court of Appeals ruled that the first step in the regulation of a
hazardous or toxic air pollutant was to determine a safe or acceptable
level of risk based only on health factors without regard for technical
feasibility or cost. However, the regulation of HAP exposures without
consideration of social and economic costs or technical feasibility was
difficult to implement and only seven HAPs were regulated under the
1970 Amendments.
Consequently, Congress established in section 112 of the 1990 Clean
Air Act Amendments (1990 Amendments) a new regulatory process for HAPs.
First, a list of HAPs was specifically mandated by Congress and EPA was
required to publish, over an 8-year period, MACT standards for the
sources of the listed HAPs. Next, 8 years\1\ after publication of each
MACT standard, the EPA was required to promulgate additional standards
if needed to ensure protection of public health and the environment. In
other words, the risks remaining after imposition of the MACT
standards, the so called residual risks, would be determined and
additional controls imposed if those risks are judged not to meet the
``ample margin of safety'' criterion. The EPA began publishing MACT
standards in late 1993 and was supposed to be completed with the entire
program this year, although that is unlikely to happen.
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\1\ The first group of MACT standards was given 9 years.
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While relatively straightforward in concept, implementation of the
residual risk requirements under section 112(f) of the 1990 Amendments
has been difficult and is far from complete. One hurdle was cleared
with the definition of ample margin of safety in 1989. EPA's published
risk decisionmaking policy set as a goal: ``(1) protecting the greatest
number of persons possible to an individual lifetime cancer risk level
no higher than approximately one in one million (1
10-6), and (2) limiting to no higher than approximately one
in ten thousand (1 10-4) the estimated risk that a
person living near a source would have if exposed to the maximum
concentrations for 70 years.'' EPA further stated that a maximum
individual risk (MIR) of one in ten thousand should ordinarily be the
upper end of the range of acceptability. As risks increase above this
benchmark, EPA stated that they become presumptively less acceptable
under section 112, and would be weighed with the other health risk
measures and information in making an overall judgment on
acceptability.
This risk policy has largely been accepted and it was codified in
the 1990 Amendments in section 112(f)(2)(B). However, it has
limitations in that it only addresses cancer, inhalation risks, and
risks to individuals. We now know that many HAPs are not carcinogens,
that humans can be exposed through ingestion and skin contact, and that
broader population risks must also be considered in addition to
individual risks. EPA has not yet provided complete guidance for how to
treat noncarcinogens and population risks in making decisions under the
residual risk program.
Recognizing that substantial work remained to be done in planning
and implementing the residual risk requirements of the 1990 Amendments,
Congress required in section 112(f)(1) that the EPA submit a report to
Congress that describes Agency plans for complying with the
requirements of the 1990 Amendments dealing with residual risks. As
noted above, EPA submitted in March 1999 the final Residual Risk Report
to Congress (Report No. EPA-453/R-99-001). The report describes a
residual risk assessment strategy design that involves at least two
tiers of risk assessment a screening assessment followed by more
refined assessment for those HAPs and sources with a potential for
excess human health or environmental risks. A specific concern of mine
is that the necessary refined levels of assessment, the methods for
estimating the refined risks, and the criteria for determining when and
how they are to be used, have not been articulated. Some of the
specific scientific and technical issues are described below.
scientific and technical issues
There are several scientific and technical issues that will be
important to many future residual risk and comparative risk
assessments, issues that have not yet been fully addressed. For
example, section 112(f)(2) in the 1990 Amendments requires
consideration of the environmental effects (also called ecological
effects) of HAPs in addition to human health effects. This requirement
was new in the 1990 Amendments and encompasses risks to wildlife,
aquatic life, or other natural resources. These risks largely result
from HAPs, such as PCBs, dioxins, and mercury, that are persistent and
can bioaccummulate. The EPA has published broad guidance for conducting
ecological risk assessments (Guidelines for Ecological Risk Assessment,
EPA/630/R-95/002F, April 1998), but substantial interpretation and
judgment are necessary for their application.
As noted above, HAPs in the past were defined and regulated
primarily based on adverse effects resulting from inhalation of the
pollutant by humans. More recently, the EPA has begun broadening this
to consider all potential routes of exposure. For example, HAPs may
deposit on, and be adsorbed into soil, plants, and surface waters with
which humans can come in contact. Contaminated food crops, animal food
products, and fish that are consumed by humans may result. These risks,
too, are largely associated with HAPs that can bioaccummulate. Other
EPA programs are requiring multipathway risk assessments in some
instances but multipathway risk assessment is new to EPA's residual
risk program; to date, the principal experience has been with hazardous
waste combustion sources and some hazardous waste sites. One problem is
that multipathway risk assessments have typically been designed and
applied to individual facilities and they require extensive data and
analysis. When these applications are focused on facilities, the use of
site-specific data in lieu of generic assumptions is found to make an
important difference in the risk outcome. Application to broad source
categories is a very different matter. These assessments will tend by
necessity to rely on conservative (meaning health protective), generic
assumptions. However, intensive and focused efforts are needed to
identify the generic parameters that are the risk-drivers through a
sensitivity analysis to replace the generic assumptions with more
accurate scientific data.
EPA is also considering the estimation of broader population risks
in addition to individual risks in the residual risk program. For
example, EPA's ample margin of safety language requires the protection
of the ``greatest number of persons'' to a risk no greater than one in
one million. However, the manner in EPA will address population risks
has not yet been defined. One risk characterization process was
described in the 1994 National Research Council report (Science and
Judgment in Risk Assessment) as including two population risk metrics:
(1) distribution of individual risk across the exposed population
(e.g., the number of individuals at risk in various risk intervals such
as 10-3 to 10-4, 10-4 to
10-5, and 10-5 to 10-6), and (2)
estimated population risk, expressed as average annual incidence.
current application of residual risk assessment
To date, as noted above, EPA has completed just one draft residual
risk assessment, a case study of the secondary lead smelting industry,
which was reviewed by EPA's Science Advisory Board (SAB) on March 1 and
2, 2000. I reviewed this draft assessment in detail and presented oral
comments to the SAB. In my comments, I concluded that the SAB's
comments on the earlier Residual Risk the Report to Congress had not
been fully addressed in formulating the case study. Significant gaps in
the science, the methods, and the data remain that can only be resolved
through more detailed assessment, often including source and site-
specific assessments.
EPA appropriately described a tiered process where an initial,
conservative screening assessment is done to conserve resources.
Depending upon the results, the tier one assessment is to be followed
by a more refined assessment; where risk outcomes are low, this
screening assessment can indicate no further study is needed. However,
where risks are of possible concern, a clear commitment is needed to
refine the screening level assessment and to articulate criteria for
when and how to provide a more accurate assessment. Currently, EPA has
not provided clear guidance on the necessary levels of refinement, the
methods and data to be used, or even the criteria for deciding when and
how to initiate the refined assessment. These are critical to making
responsible and scientifically sound regulatory decisions. While I am
sensitive to the Agency's resource limitations and the resultant
inability to conduct full site-specific risk assessments for every HAP
source in every source category, I believe that more refined source
data can often be reasonably obtained and utilized to further refine
the assessments. The Agency must be equally sensitive to the profound
potential economic impacts of further residual risk regulation of
sources that have already expended tremendous resources in meeting MACT
standards. I strongly support the need to further regulate any source
that is found to clearly and unambiguously exceed acceptable risk
levels. However, I do not believe it is in the Nation's best economic
interest to force needless expenditures when residual risks are not
excessive. A refined risk assessment is needed in order to make these
determinations. The use of upper bound generic approaches usually
provides a poor basis for regulatory actions.
Even implementation of the two-tiered strategy described in the
Report to Congress is associated with a number of likely problems.
First, given the growing complexity of the science of risk assessment
and the wide variability in HAP sources, more than two tiers of risk
assessment will usually be needed to ensure relative accuracy as well
as cost- and resource-effectiveness. These considerations are necessary
because screening risk assessments, with rare exception, estimate risks
that are excessive, which can mislead the regulatory process,
unnecessarily raise public concern, and possibly miss identification of
the most important risks. Recent studies that I and my colleagues at
Sciences have conducted concluded that these two tiers of risk
assessment can be associated with risk differences of several orders of
magnitude.
The Report to Congress also implied that the EPA would conduct all
of the necessary residual risk assessments for the more than 175 source
categories. However, our knowledge of the EPA HAP regulatory program
and staff, based on past working relationships and recent personal
communication, indicate that the Agency almost certainly does not have
the resources to accomplish this enormous assignment. The more likely
outcome is that the EPA will rely on more simplified models and
averaged, rather than site-specific, data. This approach will typically
define residual risk estimates that are greater than actual risks.
These simplified approaches cannot adequately inform regulatory
decisions.
With inadequate resources and substantial data gaps, I can see no
way for EPA to carry out the residual risk program within the
prescribed time without outside partnerships to aid in developing
appropriate information, working together, where possible, to ensure
that the best data and methods are used in the Agency's analyses, and
filling the EPA's resource shortfall with analytical and data gathering
support. In addition, with risks estimated using ``model plants,''\2\
and other approaches that rely on averaged data, industrial facilities
will often need to ensure that more site-specific data and methods are
employed to determine whether the model plant risks are realistic. In
our work, we have found that these averaged approaches typically lead
to risk overestimates.
---------------------------------------------------------------------------
\2\ Model plants are generally composites serving as average
examples of groups of typical industry facilities.
---------------------------------------------------------------------------
For many industrial source categories, the initial conservative
screening assessment could find that residual risks are unlikely to
exceed levels of concern at any industrial facility and no further
risk-related regulation would be forthcoming. However, for many other
source categories, much more accurate and rigorous assessments may be
needed in order to determine whether further regulation is required. In
other words, if a screening approach indicates risks near or above
presumptively acceptable risk levels, or ecological, population, or
multipathway risks are potentially indicated, much more detailed and
accurate assessments will be indicated. A sensitivity analysis should
be performed early in the process to determine those site-specific
parameters that are the most important to the risk outcome. These are
called the risk drivers. Data collection can then be focused more cost-
effectively. In some cases, individual facility, site-specific risk
assessments using probabilistic exposure and risk assessment techniques
will be required to define the most realistic risks for the facility.
The criteria and methods for conducting these more refined assessments
must be established, including the following:
1. Detailed characterization of the industry sources (point and
area) including location and dimensions of all emission sources,
emission quantities, building sizes and shapes, and other relevant
factors.
2. Detailed characterization of the surrounding terrain, including
U.S. Geological Survey topographical and digital elevation maps.
3. Detailed characterization of the population distribution, often
within 50 kilometers around the facilities.
4. Hourly, onsite meteorological data or, if not available, long-
term data from the nearest National Weather Service station.
5. Specific emission characteristics, including release height,
temperature, and velocity, and duration and upset conditions.
6. Agreement on appropriate dispersion models to be used.
7. Agreement on, and often reanalysis of, appropriate health
criteria to be used for the emissions (see the discussion of the IRIS
data base later in this testimony).
8. Agreement on, and often reanalysis of, other health effects
besides cancer risks to be considered.
9. Identification and assessment of possible ecological concerns.
10. Identification and assessment of multipathway effects,
including defining realistic pathways and receptor considerations
(e.g., it is rare that a farmer eats 100 percent of his daily diet from
farm grown poultry, beef, pork, and produce).
specific areas of concern with epa's residual risk case study
The process used by EPA in its first residual risk assessment was
an appropriately conservative first step that is useful for setting
priorities for assessment while conserving Agency resources. However,
as presently developed and described by EPA, the process remains a
screening tool that can reasonably exclude sources from further
assessment, but cannot with accuracy determine whether the residual
risks associated with any specific source are above or below accepted
levels of risk concern. If used more broadly, the process is almost
certain to result in a significant number of false positives namely,
sources for which additional regulation appears needed when, in fact,
the actual risks are below acceptable levels of concern. This outcome
is likely to occur because screening level risks are calculated without
properly accounting for the many limitations and uncertainties in the
data, models, and methods used by EPA in conducting the assessment, and
because of the intentional bias to protect public health where data are
uncertain. Inappropriate regulation can only be prevented by the use of
much more refined assessment, often including site-specific or
category-specific data, thus allowing the decisions needed to support
further regulation of those sources that require further control. One
illustrative example of the problem caused by reliance on screening
tools was an initial screening level analysis that indicated that most
of the Nation's coke ovens were above EPA's acceptable cancer risk
level as provided in the 1989 benzene decision. Site-specific analysis
of several facilities using improved data, a better model which we
developed, and health criteria that we re-evaluated, actually found
residual risks to be on average three orders of magnitude below the
screening level risks and actually well below EPA's acceptable cancer
risk level.
In cases where substantial uncertainties and significant
limitations in data exist, risk management decisions should not be made
until these limitations are appropriately addressed. In its initial
residual risk assessment of the secondary lead smelting industry, EPA
concluded that the risk estimates likely fell ``between the estimates
made with and without fugitive dust emissions.'' This risk range
spanned more than two orders of magnitude and is so large that the
results are impossible to interpret. In this case, at a minimum, better
quality, site-specific data of such risk-drivers are needed to refine
the risk assessment so that the results are useful.
EPA's use of conservative methods, models, data, and assumptions
early in a source category analysis is appropriate to conserve Agency
resources and help prioritize actions for later analysis. However, the
use of implausible and unrealistic methods, models, data, and
assumptions, particularly when better methods and data are easily
obtained, is clearly inappropriate and in this case led to a number of
potentially erroneous conclusions. For example, EPA's first draft
residual risk assessment resulted in risk estimates high enough that
(if true) serious adverse human health and ecological effects would
likely be easily observable in the nearby areas. However, the lack of
apparent evidence of significant human or ecological impacts near the
sources of concern gave every indication that EPA's estimates were
unrealistic. Inaccurate and incomplete data, coupled with excessively
conservative assumptions, lead to excessive risk estimates. Two
specific examples are described below:
1. The assumption in the residual risk assessment that a local
farmer obtains drinking water from an untreated local surface water
source that exceeds maximum contaminant levels (MCL) for antimony is
unrealistic. More realistically, water would be obtained from wells or
public water systems. This assumption was not conservative, it was
implausible.
2. The modeled surface water concentration near one facility
resulted in estimates of huge fish tissue concentrations and large
potential risks to the recreational fisherman. Moreover, the modeled
concentrations were sufficient to cause serious effects for aquatic
organisms, such that there would be a question of fish availability for
consumption. However, the lack of collaborative evidence (e.g., fish
kills in the vicinity of secondary lead smelters) indicated that the
estimates substantially over predicted actual concentrations. High
estimated risks need to be flagged and confirmatory information needs
to be developed.
EPA's first residual risk assessment process also was incomplete
because it left unaddressed many potentially important issues that
could have significant impacts on the ultimate residual risk estimates.
For example:
1. While EPA clearly put a lot of effort into many aspects of the
risk assessment process, it did not focus its data collection efforts
on the most sensitive risk-driving parameters. EPA further described
the assessment as an ``iteration,'' stating that it would be replaced
with a more refined, and possibly site-specific, assessment pending
SAB's comments and any additional emissions information, as necessary.
Although EPA did not provide further details on the next iterations, I
believe that the SAB clearly should review the most refined assessment
intended to provide the best basis for their scientific evaluation and
comment.
2. EPA identified major issues and uncertainties at the end of each
section of the assessment but the issues and uncertainties were only
dealt with qualitatively and no indication was provided as to how these
issues and uncertainties would be addressed in the context of the
downstream risk management decisions on this or other industry
categories.
3. While EPA acknowledged substantial gaps in data, methods, and
procedures, it was not clear what the Agency will do about the missing
information. EPA could choose to move ahead with residual risk
regulation based on this level of assessment for this source category
and plan to keep returning to the source category to further revise the
regulations every time new guidance or methods are finalized; however,
regulation based on inadequate assessment information will undoubtedly
lead to inefficiency and waste.
4. There was no discussion on how the risk assessment results will
be applied in a risk management decision.
EPA's first draft residual risk assessment also utilized emissions
data gathered from limited, short-term stack tests at limited numbers
of facilities, which was then assumed to represent long-term averages
for all facilities. Fugitive emissions estimation procedures were also
admittedly poorly characterized and uncertain. Use of limited emissions
data can dramatically affect the risk results. The uncertainties are
compounded by the fact that modeling of fugitive emissions is much more
difficult than for stack emissions. For example:
1. In its first residual risk assessment, EPA frequently stated
that its estimation of fugitive emissions is uncertain, but continued
to use the uncertain data, which can be a risk-driver, to develop risk
estimates. The uncertainty in fugitive emission estimates, especially
for particulate matter, is common, owing to the technical difficulty in
capturing or measuring the emissions. This fact argues strongly that
better data be gathered to minimize the uncertainties in the estimation
of fugitive emission rates and composition, before these uncertainties
are carried through the risk assessment.
2. EPA also used after-MACT emissions which were estimated to
support the proposed MACT published in 1995, rather than actual,
measured current after-MACT emissions. Because industries are typically
complying with the MACT standards by the time (i.e., 8 years after the
MACT standard is published) the residual risk assessment is conducted,
actual after-MACT emissions data should be used. The use of real world
data, when available, even in the initial screening level assessment is
appropriate.
Recent multipathway risk assessments typically prepared or overseen
by EPA are much more site-specific than the evaluation presented in the
first draft residual risk assessment. This assessment utilized numerous
assumptions and procedures that were not only implausible, but easily
corrected. Furthermore, many of the input parameters were questionable.
If realistic comparative risk and residual risk regulatory and economic
decisions are to be made using risk assessment, it is essential that
the models, methods, data, and assumptions be appropriate, validated,
and properly used. A major uncertainty arises from the use of models
that are both incomplete and not designed to rigorously address the
issues involved with residual risk assessment and regulation. In the
residual risk assessment, for example:
1. The oral exposure-dose equations do not include a
bioavailability factor, thereby assuming that 100 percent of a chemical
is absorbed upon exposure. The assumption that the bioavailability of
all chemicals is 100 percent is contrary to the scientific literature
and has the potential of leading to considerable overestimates of
exposure dose (e.g., absorption of a chemical that is adsorbed to
particulates or soil may be significantly hindered).
2. The assessment also assumed that particulate matter
concentrations are available in the breathing space of a resident near
the source. Air concentrations directly produced from the air
dispersion modeling are simply multiplied by an inhalation rate to
calculate the inhalation dose, and, hence, assume 100 percent retention
and absorption of this air concentration. In fact, a smaller percentage
of inhaled particles are retained in the lung, and depending on the
size of the particulates, some of the inhaled particulates will be
deposited in the respiratory tract, where a considerable fraction will
ultimately be swallowed and should, therefore, be added to the
ingestion pathway where oral bioavailability would govern the
absorption of the chemical.
3. In many instances, default parameter assumptions were relied
upon without accounting for the characteristics of a site. The reliance
on generic default values for key parameters in lieu of site-specific
data significantly decreases the likelihood that the modeled exposures
will provide a reliable indication of actual exposures. Examples of
inappropriate generic assumptions are: the assumption that persons are
exposed 24-hours per day to outdoor air at their residence; use of home
grown produce and animal products representing 100 percent of an
individual's intake of these products; use of default soil-to-plant
uptake factors (these vary considerably depending on soil types and
local geochemistry); and, selection of inappropriate exposure pathways.
4. Uptake of metals into fruits and vegetables often drives the
home gardener's indirect pathway risks and is one of the pathways for
which great uncertainties exist. Plant uptake also has important
implications for the meat and milk pathways. The generic guidance used
in the first residual risk assessment greatly simplified the
methodology for assessing concentrations in fruits and vegetables. This
process has historically been subject to many different methodologies
and data sources and this pathway has been one of the most difficult
areas for risk assessors to model. The empirical values used to predict
soil-to-plant transfer of metals are approximate over a wide range of
soil conditions. Soil geochemistry (e.g., pH) is an important factor in
the bioavailability of metals to plant roots and governs metals uptake
into the edible portions. It is recognized that sufficient data often
may not exist to characterize uptake using geochemical soil parameters
and, therefore, default uptake factors are often used. Nevertheless,
where pathways that rely on plant uptake drive the risks, a site-
specific assessment must account for the effect that local soil
conditions have on plant uptake; the risk outcome most likely will be
changed substantively.
5. The draft residual risk assessment concludes that the drinking
water pathway accounts for 73 percent of the total cancer risk and 70
percent of the total non-cancer risk for a subsistence farmer at the
site with the highest ingestion (indirect pathway) risks. Drinking
water also accounts for 97 percent of the farmer's indirect exposure
cancer risk and 79 percent of the indirect exposure non-cancer risk.
Notwithstanding the fact that the surface water concentrations are
likely to be overestimated due to the assumptions regarding fugitive
and stack emissions and shortfalls in the dispersion modeling, the
unrealistic assumption was made that nearby surface water is used
untreated for drinking water purposes. It would be illegal for any
public water supply system to supply drinking water with the estimated
levels of contaminants.
6. Several key inputs to the air dispersion model were not
included. For example, all of the emission points at a facility were
assumed to be co-located at the center of a facility; fugitive
emissions were modeled using the same source area at each facility; and
building downwash and local terrain features were not accounted for.
Inclusion of these inputs is easily accomplished and could have a
significant impact on the resulting concentration estimates and risks.
The uncertainty/variability analysis in the first residual risk
assessment was limited in its scope and usefulness. The purpose of an
uncertainty/variability analysis is to focus on the facilities,
pollutants, and exposure pathways with the highest risks identified in
the multipathway analysis. The first residual risk assessment does not
say how the quantitative uncertainty analysis will be used in the
regulatory processes. In addition, the evaluation implied that most of
the meaningful uncertainties had been accounted for and that the
results supported and validated the point estimates. However, of four
possible input parameter categories--emissions, transport and fate,
exposure, and dose-response--only two, namely emissions and exposure,
were addressed in the uncertainty analysis. Omission of two parameter
categories sidesteps the issue of developing a complete framework for
treating the risk quantification in a realistic manner. Furthermore,
many exposure variables have not been studied to establish their
chemical and physical distributions (e.g., variability in consumption
of farm grown produce and animal products).
Even given the limited scope of the uncertainty analysis, the input
parameters used in the Monte Carlo analysis addressed only a narrow
subset of the factors that influence the deterministic risk outcomes.
Emission variables that could not be quantified for probabilistic
analysis included: detection limits; test results from one facility
used to quantify emissions at another facility; frequency of plant
closing; and, fugitive emission estimates. The study ultimately relied
on very limited emissions data. These are challenging issues that are
resource intensive to address but, nevertheless, can have an enormous
impact on the risk outcome.
In the case study residual risk assessment for the secondary lead
smelting industry, screening level ecological risk assessment was
conducted to estimate potential risks to aquatic and terrestrial
communities from HAPs emitted from the facilities that remained after
the initial screening. This screening level ecological analysis was
intended to identify which HAPs require more analysis and was designed
to be conservative, with assumptions generally overestimating actual
exposure concentrations, thus overestimating the actual potential for
ecological risks. The ecological screen indicated a high potential for
ecological impacts but the results are misleading for the following
reasons:
1. The screening level ecological assessment does not provide
sufficient information to draw appropriate conclusions as to whether an
adverse environmental effect, as defined in section 112(a) of the 1990
Clean Air Act Amendments, has occurred. Section 112(a) states that
``[T]he term `adverse environmental effect' means any significant and
widespread adverse effect (emphasis added), which may reasonably be
anticipated, to wildlife, aquatic life, or other natural resources,
including adverse impacts on populations of endangered or threatened
species or significant degradation of environmental quality over broad
areas.'' This appears to provide a much broader definition of
ecological effects than was used in the case study, requiring
significant and new methodological and data needs.
2. The ecological receptors are representative of sensitive species
and communities at a generic site; no regard was given to site-specific
information.
the role of epa's integrated risk information system data base (iris)
The accuracy of comparative risks and residual risks relies heavily
on toxicity criteria from EPA's IRIS data base. Let me present here a
brief history of the development of IRIS and why it is uniquely
important to the risk assessment process. I will also discuss the
limitations and problems of IRIS in meeting the Agency's current risk
assessment goals.
IRIS is an electronic data base containing information on human
health effects that may result from exposure to various chemicals in
the environment. I played a significant role in establishing the IRIS
data base at EPA. The initial purpose of IRIS was to compile health
information into one central data base, and to ensure internal
consistency among the various EPA Regions' and Offices' health
assessments. It was originally planned for internal use only, and was
never intended for direct regulatory use without the careful scrutiny
by the Agency. Indeed, the original disclaimer to the preface of each
IRIS file clearly indicated that the IRIS summaries are subjected to
constant revisions to incorporate new data and new methodology, are
subject to review by EPA scientists, and are designed to be used to
support risk assessments. There was no mention of any direct regulatory
purpose for the IRIS data base.
In recent years, there has been increasing reliance on IRIS for
toxicological information and regulatory guidance, even though the
latter is inconsistent with its original purpose. In recognition of the
need for a more streamlined approach to preparing IRIS assessments and
to establishing consensus, the Agency recently initiated a commendable
IRIS pilot program. Briefly, the program entails the development of
chemical-specific ``Toxicological Review'' health assessment documents
prior to updating or developing an IRIS summary, input from the public,
and external peer review process. On April 1996, EPA announced in the
Federal Register that 13 substances will be reviewed under the pilot
program. To date, 10 of the 13 substances have been updated. Obviously,
the progress made by the pilot program in updating the IRIS files has
been slow, which could have serious impacts on a program, such as the
residual risk assessment program, which have a required completion
schedule. The IRIS data base currently contains over 500 chemicals,
including the 188 HAPs required to be regulated in the residual risk
program. Many of the IRIS files are outdated and, while updating is
laudable, 10 updates in 4 years is an entirely inadequate response.
Reasons for the slow progress include resource limitations. In
addition, new advanced methods to perform RfD's/RfC's and cancer
assessments are being developed, including new methods for dosimetric
adjustments, benchmark dose methodology, categorical regression
analyses, biologically based models with consideration of mechanism of
action, and physiologically based pharmacokinetic (PBPK) models. Thus,
updating an IRIS file necessitates not only updating and evaluating the
most recent literature but also reassessing the data using these new
and complex methods.
As mentioned earlier, EPA's first residual risk assessment relied
on toxicity criteria obtained from IRIS. However, the IRIS files were
not reviewed to determine whether they were outdated. If a particular
chemical is a risk driver in the residual risk assessment, the validity
of the toxicity factors used must be investigated. Acceptance of
published IRIS criteria without review can lead to considerable
uncertainty in the final residual risk results. For example,
reevaluation of EPA's cancer unit risk value for coke oven emissions by
my company found, using updated epidemiological data and techniques,
that the actual cancer unit risk factor is about one-fourth of the IRIS
``official number'' for coke oven emissions which was prepared in 1984
under my direction. That evaluation was intended only as an initial
value pending publication of epidemiology studies that were undertaken
at the time. However, our reevaluation was provided to EPA about 2
years ago, but IRIS still has not yet been updated. Clearly, a 1984
evaluation based on limited and unpublished data is inadequate for use
in regulatory decisionmaking in 2000.
In summary, IRIS was not originally intended to be used for
regulatory purposes or for that matter to provide complete
toxicological data on a particular chemical. It is most useful as a
screen that allows one to quickly access toxicity information that may
be of help for risk assessment purposes. It is clear that there is a
serious need to update IRIS. The use of outdated IRIS information has
serious implications to the use of any risk assessment in
decisionmaking.
Risk assessment provides a thorough evaluation of scientific
literature as a basis for regulatory decisionmaking and provides the
impetus for improving the process in order to facilitate better
decisionmaking. Risk assessments support many different kinds of
decisions. In comparative risks assessments, the totality of the risks
are viewed to improve priority setting, decisionmaking, and stakeholder
involvement. Residual risk assessments support specific decisions
mandated under the risk requirements of the Clean Air Act. These
decisions demand well thought out, comprehensive, and scientifically
supported risk assessment methodology. This need poses an unprecedented
challenge for EPA to develop the processes and then conduct
comprehensive risk assessments across a range of chemicals, sources,
and regulatory programs. This places heavy resource demands on EPA, and
the required resources may not be available. Nevertheless, it would not
serve our Nation well to make regulatory decisions under any program by
defaulting to generic risk assessment approaches or using out of date
data files in IRIS because of resource constraints. The best science
should form the basis for risk management decisions; otherwise our
decisions are not well informed and can be flawed. It is also crucial
for all stakeholders to have at least some understanding of how EPA
intends to use the information developed in the residual risk
assessment to make risk management decisions. Only then can the
assessment's adequacy be judged.
The first residual risk assessment conducted by EPA is not
sufficient to meet the needs of decisionmakers under the residual risk
program. At best, it presents a process that can only be described as a
screening assessment, even when including multipathway and ecological
analyses. A screening assessment is a necessary part of the initial
risk assessment process for this program, but it falls far short of the
refined risk assessment (based on more source-category specific data)
that is required to make regulatory decisions.
Earlier this year, the SAB reviewed the EPA draft residual risk
assessment method and its first application to the secondary lead
smelting industry. Because the method requires substantial improvement,
it is essential for the SAB to review the next draft of this approach.
More refined risk assessments should not simply be screening
assessments with more data; rather, they should rely on new methods and
approaches to address important risk factors such as when to refine
conservative screening values, how to assess population risks, how to
characterize after-MACT standard emissions, how to assess ``significant
and widespread adverse'' ecological risk, when monitoring data are more
suitable than modeled data, and what criteria will be used to determine
when the risk assessment process will be triggered. These
methodological issues need to be reviewed by the SAB because they are
not settled matters in the realm of risk assessment and will be of
generic importance across most, if not all, of EPA's risk assessment
programs.
Any more refined risk assessment methodology should be
characterized by the use of category-specific, and selected site-
specific, data for the elements that are the risk-drivers as identified
in screening assessments. The generic assumptions used in a screening
assessments such as those conducted by EPA are designed to be
conservative; consequently, they can generate many false positives.
Regulatory decisions cannot be based on such assessments; more specific
data are needed to determine whether or not actual residual risks of
concern exist. While this task varies in degree of difficulty, EPA can
focus its further data collection on those elements identified by the
screening assessment as the risk-drivers. Much of those data should be
readily obtainable.
The residual risk assessment methodology should also explicitly
incorporate realistic assumptions and data in both the screening and
more refined phases of the assessment. As seen in EPA's case study
assessment of the secondary lead smelting industry, implausible or
unrealistic assumptions, methods, and data can fatally skew the results
of an assessment. Such results have the potential to cause needless
data gathering by EPA and industry in order to demonstrate that
nonexistent risks are not real; unfounded public concerns may also be
avoided if the results of a screening assessment are immediately
scrutinized to determine if they are realistic.
Finally, if the IRIS data base is to be used for regulatory
purposes or for that matter to provide complete toxicological data on
any particular chemical, it must be updated across the board and then
maintained in an up-to-date manner. The use of outdated IRIS
information has serious implications to the use of any risk assessment
in decisionmaking.
conclusions
Extraordinary complexity of the risk assessment is called for by
the comparative risk and residual risk programs. In 1976 when the first
risk assessment process began at EPA, risk assessment and risk
management focused largely on single chemicals such as air pollutants
and pesticides. The complexity of risk assessment has grown over the
years with the most complex risk assessments being conducted at
Superfund sites and for combustion sources. These risk assessments
addressed multipathway risk assessment issues and ecological risks but
have been focused on single facility or single sites. The comparative
risk program and the residual risk program as prescribed under the
Clean Air Act Amendments of 1990, require unprecedented use of risk
assessment across the board for over 175 industry source categories and
literally thousands of facilities. In addition, the residual risk
program, for example, must address the toxicity of all 188 chemicals on
the hazardous air pollutant; the comparative risk program needs to
address considerably more chemicals. Adding considerably more to the
complexity, the residual risk program calls for the use of multipathway
risk assessment and regulation of environmental risks with significant
and widespread effects to wildlife, aquatic life and other natural
resources, including impacts on endangered or threatened species or
significant degradation of environmental quality over broad areas.
The current EPA guidelines for conducting the residual risk program
(and there are no such guidelines for the comparative risk program but
it probably will follow much the same process), primarily employ
available data and generic and upperbound risk assessment approaches.
The guidelines mention a tiered approach but do not make a clear
commitment to proceeding to a clear approach where risks appear to be
high nor are there any guidelines or criteria for when or how to do so.
recommendations
1. The unprecedented complexity and cost of conducting the risk
assessment program called for by both comparative risk and residual
risk must be conducted by a carefully orchestrated tiered approach. The
first tier should employ the very best available data and commit to an
approach that provides the greatest accuracy possible in the risk
assessment at this stage so as to avoid unfounded public health
concerns over issues that may not be of substance. The risks that are
so identified should also be subjected to an analysis to see if they
appear to be unreasonably high. Several examples of such unreasonably
high risk have been given in this testimony. For those sources that
appear to have low risk after the Tier 1 assessment, no further work is
needed. For other sources, if the risks appear high, a sensitivity
analysis should guide further data collection to focus resources on
refining those parameters, including toxicity values, to arrive at a
more accurate risk assessment. Refined risk assessments that are
focused on defining real risk are necessary to guide the risk
management decisions. The resources necessary to conduct these risk
assessments both within EPA and on the part of involved parties, need
to be recognized. In addition, I see no way that these risk assessments
can be refined without some kind of partnership to refine data with
involved parties.
EPA's current draft guidelines fall far short of addressing a
process that will ensure that any of these steps are followed beyond
providing the initial upperbound risk assessment. The shortcomings of
effort are laid out in considerable detail in this testimony.
2. Policy related issues need to be clarified. Historically, EPA
has limited its risk guidance in the hazardous air pollutant regulatory
program to carcinogens, inhalation risks, and risks to individuals, and
has not addressed how broader population risk must be considered.
Further, language in the 1990 Clean Air Act Amendments for residual
risk states that environmental risks must also be considered. These
policy issues together with how multipathway risk assessment will be
considered under the residual risk program should be clearly
articulated at this time. There should be an opportunity for public
comment to arrive at final criteria to define how these issues are to
be addressed and guidance must be developed to more accurately estimate
the effects.
3. Emissions data must be improved. Historically, EPA has used
readily available emissions data, for example using estimated rather
than measured post-MACT emissions, to estimate current risk. The risk
assessment can be no more accurate than are the emissions that are used
in the dispersion modeling.
I recommend first that the most accurate available emissions data
be used in the Tier 1, screening level risk assessment. Second, for
those sources that appear to be associated with risks of concern, I
recommend that subsequent refinements in the exposure data be sought
before a final risk assessment is completed. Again, I see no way for
EPA to arrive at the necessary accuracy in risk assessment without a
partnership with the organizations and facilities involved.
4. Use of the IRIS data base, as a repository of operational,
regulatory toxicity values, must be revised. Historically, the IRIS
data base was established to provide a repository for all of the
information available in the agency with respect to toxicity for
particular chemicals. Initially, it was primarily established to ensure
consistency across agency programs and to serve as an internal data
system to make available work that had been completed to date on
individual chemicals. The Risk Assessment Forum, for which I was the
first director, set up the IRIS data base and commenced the stewardship
program to enter new chemicals and to put in information that was
existing in the agency at the time the data system was established. In
the beginning, it was clear that the data base was not necessarily
intended for direct use in regulatory decisions without refinement; the
preface reflected the fact that the data base was not intended for
these purposes. Since that time, however, the IRIS data base has become
not only the most important source of regulatory toxicity values for
use across all of EPA's programs, but is widely used across State
programs and internationally as well. The files for over 500 chemicals
that are contained in this data base are in many, many cases vastly out
of date both with respect to the current literature and the use of
current methods for dose response extrapolation. To illustrate the
difficulties, EPA began in 1996 a full-scale review of 13 chemicals in
IRIS. At this time, only 10 of those updates have been completed.
The current guidance that has been issued for the residual risk
program, and practices for the comparative risk program, use these
toxicity values as if they are intended for immediate regulatory use
without refinement. This is inappropriate. All risk assessment programs
in EPA, in particular in this instance, the comparative risk and
residual risk programs, should explicitly recognize that these toxicity
values are vastly out of date and must be refined where risk drivers
are identified. This recognition should be part of the iterative
process for the Tier 2 and subsequent stages of risk assessment
refinement for these programs.
I recommend, as everyone else does, that resources be committed to
EPA to update all of the over 500 chemicals in IRIS and to keep the
data base refined and up to date. In making this recommendation, I
realize that this is an almost impossible task. Nevertheless, I think
all efforts should be made to carry it out to the extent possible. To
be totally practical, I further recommend that the preface to the IRIS
data base be re-stated to recognize reality, that is that the IRIS data
base can probably never be a current source of all the latest
information in the literature with application of the latest risk
assessment methodologies necessary to provide the accuracy essential in
risk assessment to inform risk management decisions. I further
recommend that a partnership be established between EPA and private
institutions to refine toxicity values, particular in the Tier 2 part
of a risk assessment process where risk drivers have been identified
through a sensitivity analysis. By this method, we can focus precious
resources on those most important factors that can improve the
scientific basis for our decisions.
5. Uncertainty and variability analyses must be applied more
explicitly. Historically, EPA has come to recognize the importance of
performing variability and uncertainty analysis but to date has been
able to do so only for a limited number of factors. the purpose of
uncertainty and variability analysis is to focus on the facilities,
pollutants, and exposure pathways of greatest concern to the estimated
risks identified in the multipathway analysis. Four important parameter
categories are emissions, transport and fate, exposure, and dose-
response.
Further, historically the uncertainty and variability analysis has
been stated in some cases only qualitatively and not quantitatively or,
in some limited cases, there have been quantitative statements of
uncertainty. All too often, this section of the risk assessment is an
afterthought that is never mentioned again in the risk management
process.
I recommend that there be clear guidelines developed for the use of
uncertainty and variability analysis in making risk management
decisions. I recognize that this may be a difficult task to undertake
but I think it is an important one. For example, the first guideline
could be that where uncertainty is so great, a next tier of risk
assessment is necessary before any informed risk management decision
can be made. Second, where a risk management decision is based on a
risk assessment that is highly uncertain, the decision should be
considered an interim decision until more refinements in the data and
methods can be accomplished. There should be a clear commitment to
revisit that decision as soon as the improved risk assessment
information is made available. I feel certain that guidelines such as I
have suggested here could be developed that would ensure that
appropriate use of uncertainty and variability analysis is made during
the entire risk assessment and risk management process.
Thank you for the time to address this committee, I would be happy
to entertain any questions you may have.
______
Responses by Elizabeth L. Anderson to Additional Questions from
Senator Smith
Question 1. You stated that the science of risk assessment has
grown in complexity. How and what changes do you believe need to occur
for the EPA to be able to meet those challenges you identified in
conducting risk assessments?
Response. The science of risk assessment has grown considerably in
complexity since we first Megan to apply it to environmental
decisionmaking over 20 years ago, and it will continue to evolve.
However, it has reached a State where it can provide highly useful
information to risk managers, as long as appropriate assumptions,
methodologies, and data are used and proper decisionmaking criteria are
applied. In my testimony, I identified a number of issues associated
with EPA's initial residual risk assessment. I offered a number of
recommended improvements, summarized below, that could be undertaken by
EPA in methodology, application, and resource distribution that could
help the Agency meet its challenges.
First, multiple tiers of assessment must be utilized in order to
cost-effectively evaluate wind regulate residual risks. EPA has adopted
the multi-tiered approach but the Agency's initial residual risk
assessment only used two tiers. Studies by me and my colleagues have
shown that several tiers of assessment are often needed to effectively
refine the process to distinguish the significant residual risks from
those of low importance. I recognize that this process often requires
utilization of more resources, but it minimizes the very real
possibility, arising from the use of limited tiers of assessment, of
regulating sources that do not in fact result in risks of real concern
in the exposed populations.
Second, important issues have not yet been dealt with in guidance
or practice by EPA. For example, section 112(f)(2) in the 1990 Clean
Air Act Amendments requires the regulation of environmental risks in
addition to human health risks; however, EPA has not yet published
guidance on how this should be done under the Clean Air Act. Such
guidance is critically needed to the risk decisionmaking process. As
another example, EPA discussed in the 1999 Residual Risk Report to
Congress the need to consider broader population risks in addition to
the risks to the maximally exposed individual upon which risk
assessment has focused in the past. Again, guidance for considering and
dealing with broader population risks has not yet been published, and
is critically needed.
Third, EPA has historically used available emissions data in
conducting risk assessments, even when the data were limited and out-
of-date. Risk assessments can be no more accurate than the emissions
data used. I recommended in my testimony that EPA strive to improve its
emissions data base and that essential to that outcome are partnerships
with the organizations and facilities that have the best and most
current data. The National Research Council, in its recent report
Strengthening Science at EPA: Research Management and Peer Review
Practices, also urged EPA to acquire and apply the results of research
conducted or sponsored by other Federal and State agencies,
universities and industry.
Fourth, EPA's integrated risk information system (IRIS) data base
must be revised and updated. As I discuss in the response to the next
question, much of IRIS is out of date and if it is to be used in
regulatory priority setting and decisionmaking, necessary resources and
management direction must be applied to improve it and its application.
I expand on specific recommendations in my written testimony.
Finally, the use of uncertainty and variability analysis must be
applied more explicitly. While EPA has historically recognized its
importance, this process has been used only in a limited way. Guidance
for its more explicit use must be developed and then applied
systematically in the risk assessment and risk management process.
Question 2a. How many values are there currently in the IRIS data
base, and how many of them, to your knowledge, have been updated? What
is involved in reviewing and updating an IRIS value and how important
is this review to the residual risk program and other risk-driven
regulatory programs at EPA? How much could an IRIS value change as a
result of this review and what would it mean for the final risk
assessment?
What is the Size and Status of IRIS?
Response. According to the EPA Summary Report: Characterization of
Data variability and Uncertainty: Health Effects Assessments in the
Integrated Risk Information System, (August 2000 review draft) stated
that there were 537 chemical specific assessments in IRIS as of January
31, 2000. One has been added since that time, for a current total of
538.
According to the September 26, 2000, SAB letter to the
Administrator entitled Review of the Draft Report to the Congress
``'Characterization of Data Uncertainty and Variability in IRIS
Assessments, Pre-Pilot vs Pilot/Post-Pilot'', the average IRIS file was
last changed 10 years ago. In many cases, the last activity was when
the file was first added to the data base. In 1995, EPA established the
IRIS Pilot Program. Since that time, four substances were added to IRIS
and 16 files were revised. Clearly, this pace needs to be greatly
accelerated both because so many files are currently out of date and
because the State of the science is changing rapidly in response to
such initiatives as the HPV program, the Children's Health Initiative,
and the endocrine disruptor screening and testing program.
Alternatively, the IRIS file should be appropriately labeled as a
reference file, not as a source of toxicity values for direct use in
risk assessment. I see no way to make informed public health decisions
that have significant social and economic costs without making
provisions to review and revise the toxicity information in IRIS as a
particular agent becomes the risk driver in these decisions.
Question 2b. What is involved in the Review and Update of IRIS?
Response. Much is involved in the review and update of an IRIS
file. These files contain scientifically reviewed information on the
carcinogenic and noncarcinogenic effects associated with exposure to a
substance. The review requires knowledge of inhalation and oral
toxicology; methods by which dose-response relationships, risk, and
uncertainty are characterized; statistical procedures used to evaluate
data; and scientific data bases relative to the health or ecological
effects of the substance under study. The sequence of events involved
in revising an IRIS file includes the following steps.
Analysis, Interpretation and Synthesis of Information and Data.--
The review initially involves obtaining the published information on
the toxicity/carcinogenicity and supporting data on the health effects
of the pollutant. Analyses of these data for validity, accuracy,
generation and characterization of exposure concentrations, and
statistical analysis of exposure and response measures determine the
usefulness of the information in establishing non-cancer and cancer
concentration dose-response relationships. Appropriate data analyses
include relatively new qualitative and quantitative dose-response
modeling techniques such as: (1) physiologically-based pharmacokinetic
(PBPK) modeling, (2) benchmark concentration (dose) analysis, (3)
categorical regression, and (4) linear dose-response or mechanistic
models. Use of these advanced methods ensures that correct conclusions,
correlations, extrapolations, and contradictory results are identified
in the process of dose-response assessment. In instances where
confidential business information (CBI) information must be used,
standard U.S. EPA CBI procedures must be followed.
Data Array Analysis, RfC/RfD/ARE and Cancer Unit Risk Derivation,
and Calculation.--Data secured for developing risk reference
concentrations (RfCs), risk reference doses (RfDs), acute reference
exposures (AREs), and cancer unit risk values must be arrayed in a
manner that can be quantitatively evaluated. The analyses involve the
identification of the critical effect, principal study, supporting
studies, and appropriate mathematical models for fitting the data
according to EPA procedures. For inhalation studies, appropriate
duration adjustments of the exposure concentration must be made
depending on whether the pollutant exists in vapor or aerosol form and
the data array modified accordingly. Derivation of the RfC, RfD, and
ARE and preparation of confidence statements involve application of
appropriate uncertainty factors, evaluation of study quality, and
identification of data base deficiencies and discussion of any
scientific controversies surrounding the chemical or effects noted.
Derivation of cancer unit risk values involves application of
appropriate models and explanation for their selection as well as
qualitative narratives categorizing the chemical's carcinogenicity. For
example, decisions must be made to employ the default approach, the
linear non-threshold dose-response model or the more refined approach
using the mode of action data, to define more accurately the dose-
response characteristics, where data are available. The difference in
outcome at low doses can be as much as several orders of magnitude.
These quantitative procedures are incorporated into a summary narrative
for peer review by the EPA and into a report describing the rationale
for developing or not developing an RfC, RfD, ARE, or cancer unit risk
values for a given substance. A support document (toxicological review)
is also prepared to go with the summary narrative. This support
document discusses in greater detail aspects of the studies described
in each of the summary narratives (e.g., the RfC, RfD, and cancer
assessment). It also provides additional toxicological information,
generally of a secondary nature, that relates to a given chemical's
effects in both humans and laboratory animals, including any pertinent
in vitro findings, such as genotoxicity results, and metabolic or
mechanistic studies.
Question 2c. How important is the IRIS review to the residual risk
program and other risk-driven regulatory programs at EPA?
Response. Accurate and current IRIS files are absolutely essential
to the legal and scientifically supported implementation of EPA's risk-
based regulations, or an alternative approach is needed. Regulations
that are based on inadequate, out-of-date, or unvalidated toxicological
data will almost certainly be challenged and would likely be
overturned. More importantly, the Agency has committed to producing
regulations based upon sound science and peer review, and many of the
current IRIS files do no meet these goals.
Question 2d. How Can a IRIS Value Change Risk Results?
Response. The IRIS value has a significant impact because it is
directly proportional to the risk estimate. In one example of the
impact of change, reevaluation by my company of EPA's published cancer
unit risk value for coke oven emissions found, using updated
epidemiological data and techniques, that the actual cancer unit risk
factor is about one-fourth of EPA's published IRIS number for coke oven
emissions. The published value was derived originally in 1984 under my
direction, but was intended only as an initial value pending
publication of epidemiology studies that were on-going at the time.
However, the file was never updated by EPA, even though the anticipated
epidemiology studies were completed. Our more recent reevaluation was
also provided to EPA over 2 years ago, but the IRIS values still has
not been revised. Clearly, a 1984 evaluation based on limited and
unpublished data is inadequate for use in regulatory decisionmaking in
2000. Use of the updated cancer unit risk value for coke oven emissions
would lower risk estimates by a factor of four. When combined with
reduced exposure resulting from an updated exposure model also
developed by my group for the coke oven industry, the estimated maximum
individual risks associated with exposure to the coke oven emissions at
the Nation's two largest coke facilities were reduced from EPA's
estimated values, which were well above the Agency's level of concern,
to values well below the Agency's level of concern. Use of EPA's
published value could lead to a conclusion that additional regulation
to reduce residual risks is likely to be required for this industry.
Our revised assessment would suggest that no additional regulation is
likely to be required for this industry. If additional regulation were
required, it could entail millions of dollars in new control
expenditures and the possible loss of hundreds of jobs from plants that
may not be able to afford the added costs and, as a result, would
close. The most important contribution risk assessment can make to the
regulatory process is to present refined information that can
distinguish the more important, real risk from the unimportant,
insignificant risk. This outcome can only evolve when screening level
risk assessments are further refined.
Question 3. What do you recommend that the EPA do to improve the
quality of its regulatory decisions in terms of risk assessment and
benefit-cost analysis?
Response. As I noted in my testimony and discussed above, I made
several recommendations in my written testimony for improvement in risk
assessments, recommendations that could significantly improve the
quality of the regulatory decisions that are needed. At the heart of
these recommendations are three principal needs. First, better guidance
and decision criteria must be developed by EPA and agreed upon that
detail the necessary processes for reaching appropriate risk decisions.
EPA has published only partial and incomplete guidance and criteria to
date. Second, partnerships must be formed between EPA and the regulated
industries to improve the quality of the data upon which risks are
estimated. Such partnerships have been ineffective for the most part
and have not been aggressively sought by EPA or the regulated
industries. finally, important EPA data bases, such as IRIS, must be
reviewed and updated to provide more confidence in the risks that are
estimated, or alternative courses of action adopted. I made alternative
recommendations in my written testimony. These improvements will take
time and resources, but could be expedited through the same kinds of
partnerships I recommend for improving the quality of industrial
facility emissions data.
Question 4. What can the Congress do to accelerate the adoption of
a more effective decisionmaking process?
Response. Section 112 of the 1990 Clean Air Act Amendments
establishes the list of hazardous air pollutants (HAPs) and defines a
general process for identifying source categories of the HAPs,
publishing emission standards based on maximum achievable control
technology (MACT), and evaluating and further regulating residual risks
at a later date, where necessary. However, section 1121eaves to EPA the
exact process for meeting this mandate. In the 10-years since passage
of the 1990 Amendments, EPA has published some but not all of the
necessary guidance and criteria for this program. The Agency has also
allocated resources to the extent possible, given its many other
important responsibilities, but there has clearly been a shortfall in
resources needed to accomplish what is required in section 112.
I believe that Congress can best influence effective decisionmaking
by several means: (1) recognizing the complexity of the tasks that have
been assigned to EPA, (2) ensuring that the rush to meet deadlines does
not jeopardize the scientific basis for making informed decisions, (3)
supporting development by EPA of the necessary criteria and guidance
for an iterative risk assessment process that can ensure that sound
decisions are made, (4) encouraging reallocation of EPA's resources in
ways that facilitate improvement in the risk assessment process, and
(5) encouraging partnerships between EPA and outside organizations that
have resources and information that can assist EPA in providing refined
and carefully conducted risk assessments to inform the regulatory
process.
______
Responses by Elizabeth L. Anderson to Additional Questions from
Senator Baucus
Question 1. Ms. Anderson, you raised many specific concerns about
EPA's residual risk assessment case study. It often seems that every
time a risk assessment is done these days--whether it is to regulate an
environmental problem, update a standard, or better understand a
problem such as climate change--it is controversial. Given this, how
realistic do you think it is for us to consider doing a comparative
risk assessment that would set EPA's budget or regulatory priorities--
something that would require a separate risk assessment for each of the
Nation's environmental problems--but still avoid controversies over
each and every risk assessment the priorities are based on.
Response. I agree that historical risk assessments have often been
controversial. However, it is important to recognize that risk
assessments can be designed to achieve different purposes and for that
reason can vary substantially in their level of sophistication and
complexity. The risk assessment aimed at setting regulatory priorities
typically would be a national assessment that evaluates broad
categories using screening tools and aggregated data. The models, the
data, and the methodologies are focused at providing general
comparisons of environmental problems to assist in setting regulatory
priorities. On the other hand, the risk assessment aimed at
establishing source category regulations and necessarily affecting
specific facility operations, control costs, and jobs, must not only be
much more sophisticated and but also often facility-specific. This
assessment process requires more precise models, facility-specific
data, and methodologies that are detailed enough to ensure that real
risks are being identified and subsequently regulated. I believe that
the science of risk assessment is currently at a level that can
effectively help us set regulatory priorities, but that to be
successfully applied to regulatory decisionmaking there must be
additional guidance, direction, resources, and a commitment made to an
iterative process to provide accurate, refined assessments for
significant regulatory decisions where the social and economic
consequences are substantial. Otherwise, it may lead to regulating
insignificant risks at great cost while real risks go unidentified and
unregulated.
Question 2a. Your testimony suggests that you oppose regulation or
making risk management decisions where there are ``substantial
uncertainties and significant limitations in data.''
Are there some good ways that Congress, EPA, or others can identify
``substantial uncertainties and significant limitations in data''?
Response. First, when I discussed ``substantial uncertainties and
significant limitations in data'' in my written testimony, I said that
risk management decisions should not be made until these limitations
are addressed. I also did not mean to imply that these uncertainties
and limitations are unanswerable. For example, as I presented in my
written testimony, a sensitivity analysis can be used to identify the
most important risk drivers. These parameters can then be inspected to
determine if better data or methods are available to refine the
particular value (e.g., refining a toxicity value from IRIS that may be
10 years out of date or replacing estimated, old emissions data with
more current and accurate data). In my written testimony, I noted a
number of areas where EPA is moving in the right direction but needs to
develop more complete guidelines and criteria for assessment and
decisionmaking. For example, to reduce the uncertainties and
limitations EPA could make a greater effort to develop and utilize
partnerships with the regulated industries to gain access to much more
accurate and complete emissions and other facility-specific data. The
science of risk assessment is at a stage where it can be accurately
used as long as appropriate assumptions, models, and data are
incorporated. EPA has been slow to gather and incorporate these
techniques but with encouragement from Congress and additional
resources I believe that risk management decisions could be made that
are realistic and supportable by the science. I have stressed that EPA
has been assigned a most complex task. I am not criticizing EPA for
tackling this enormous task; rather, I am offering what I hope are
constructive approaches to ensure that decisions are made on the basis
of sound science, not highly uncertain and perhaps incorrect portrayals
of risk.
Question 2b. Given that data collection is very time and resource
consuming, how much data is enough?
Response. I do not necessarily agree that data collection has to be
time and resource consuming. Historically, it has not been data
collection that has been time and resource consuming; rather, the time
and resource consumption has been spent in figuring out the correct
process for using the collected data in conducting risk assessments.
For example, it took EPA 8\1/2\ years to complete and publish the
Residual Risk Report to Congress, required in section 112(f)(1) of the
1990 Amendments, and almost another year after that to release the
first draft residual risk assessment. I do not believe that the delay
was data collection; rather, it was in developing a rational and
scientifically supportable process. I believe that EPA has now
developed an appropriate framework for the job that needs to be done.
However, they must go further and develop more complete guidance and
criteria to facilitate the ultimate decisionmaking. Finally, I believe
that the science of risk assessment is now mature enough that we know
when we have enough data and we have uncertainty and variability
techniques available to allow us to evaluate the quality of the data we
have and its influence on the ultimate risk estimates and on the
subsequent cost-benefit analyses.
Question 3a. You indicated that EPA's first draft residual risk
assessment resulted in risk estimates high enough that serious adverse
human health and ecological effects would likely be easily observable.
You go on to State that ``the lack of apparent evidence of significant
human or ecological impacts'' showed that EPA's risk estimates were
unrealistic. The GAO stated at the same hearing that there are serious
gaps and limitations related to environmental data. My own experience
with the town of Libby, MT, has suggested that routine monitoring of
the incidence of public disease is inadequate.
Given this, are we really in a position to see the ``apparent
evidence of significant human or ecological impacts'' to which you
refer?
Response. I agree that in many instances it is difficult to measure
the incidence of public disease. This is most difficult when the
incidence of disease resulting from a specific environmental exposure
is not significantly different from normal. The tools of epidemiology
often are not accurate enough to detect significant impacts because of
limitations such as small population size and the presence of many
confounding exposures. However, because of the assumptions and methods
used, EPA's case study assessment predicted risks in some cases that
were so high that serious impacts would almost have to have been
observed; for example, the predicted levels of some toxicants were so
high that fish would not have survived. Such toxicity impacts in
surface waters should be observable. I recommended several actions to
prevent a reoccurrence of this. First, EPA should perform a sensitivity
analysis and identify the risk drivers. Then it should reassess its
assumptions and methods related to these factors and select ones that
are more scientifically supported. Second, EPA should evaluate the
results of its calculations and determine whether the results are
realistic and make sense. Finally, EPA should conduct more complete
uncertainty and variability analyses to better understand in the
estimated quantities the lack of precision due to imperfect science and
the natural variability of the parameters in nature. In summary, I am
not suggesting a process of verifying risk based on observations, but
rather on applying good scientific principles in an iterative process.
First, resources can be conserved by performing upper-bound screening
level assessments. Second, for those circumstances where the risks
appear to be significant, identify the most significant parameters and
attempt to improve the scientific basis for these parameters and,
consequently, the outcome of the risk assessment. One check to inspect
whether or not risk assessment outcomes are realistic is to compare the
predicted levels of exposures with toxicity thresholds. Where levels
are predicted to be exceedingly high, relative to these thresholds
(e.g., approaching or above fish toxicity values), one can question
whether fish kills have been observed.
Question 3b. Is there ``evidence'' or data that disprove EPA's
estimates?
Response. EPA typically does not identify specific facilities in
their risk assessments, and industry is reluctant to have specific
risks ascribed to specific facilities. Rather, EPA relies generally on
model plants (i.e., composites serving as average examples of groups of
typical industry facilities). Thus, it is generally not possible to
seek specific evidence or data near specific facilities to disprove the
estimates because those facilities have not been identified. Our
conclusions on EPA's case study were based on the collective many years
of risk assessment experience of myself and my colleagues, and the fact
that some of EPA's estimates were so high as to be well beyond the
normal distribution and, thus, likely to be observable. In cases where
the hazard index is exceeded at the upper bound by 60 fold, if the
risks are real, effects should be observable. Such predicted high
exceedances are rare but in this case, EPA also noted that the risks
are highly uncertain because of uncertainties about fugitive emissions.
It is in these circumstances that the scientific basis for the risk
assessment must be refined before informed decisions can be made.
Question 4. I would be interested in your thoughts on what problems
would likely be encountered, and how successfully we would likely be,
if we attempted to perform a national comparative risk assessment in
order to set EPA's budget or regulatory priorities.
Response. I absolutely support establishing regulatory priorities
on a more scientifically supported risk basis and I believe strongly
that this can be realistically accomplished using today's risk
assessment science. EPA began its first comparative risk assessment in
the mid-1980's, but to the best of my knowledge that assessment was
largely exploratory in nature and necessarily utilized available
methods and data. Thus, it was almost certainly doomed to failure
because the methods and data available at that time were inadequate to
consider and compare the many complex issues, issues such as multiple
pathway exposures, ecological risks, population risks, non-carcinogenic
risks, and others. I also seem to recall that the study was conducted
with no substantial added resources to attempt to gather better data or
to develop better methods.
However, the conduct of a comparative risk assessment is possible
today, given appropriate direction and resources. A significant amount
of data would need to be gathered and methods need to be refined to
properly focus on the task but, as I noted earlier, I believe that the
science of risk assessment is currently at a level that can effectively
help us set regulatory priorities.
Question 5a. I understand that you have been critical of the EPA
and the data it chooses to use for its analyses.
Do you agree with the SAB's suggestion that, in the interest of
``sound science,'' when industry has data or analyses to inform these
risk assessments, industry should provide that information to the
Agency?
Response. I want to make it very clear that my comments on EPA's
case study were not intended as a criticism of the Agency and its
regulatory process. Given the available resources and time pressures, I
believe the Agency did the best that it could and I have been very
careful to point out that EPA has been assigned a most complex task
that has not been tackled before. My comments were more directed at the
broader issue of ``how can we better evaluate risk and use that
information to make the best decisions to protect the public health and
the environment, taking into account social and economic costs?'' In
other words, it is not possible to regulate everything indiscriminately
and it may be unnecessary. It is important to identify real risks and
assure that public health and environmental protection is appropriate
and adequate. Sound risk assessments are necessary to properly inform
the process. I provided the SAB with a number of recommendations, many
of which I repeated in my testimony. Importantly, I fully support the
SAB's suggestion that industry needs to be more involved to help
facilitate the collection and use of the best data and to share
facility-specific information that is helpful to this challenging task.
Question 5b. Is this what you meant by ``outside partnerships'' in
your testimony?
Response. Yes. Industry has historically been involved in reviewing
and commenting upon EPA's regulatory packages. EPA also regularly seeks
emissions and source characterization information through information
collection requests (ICRs). However, EPA is limited in the number of
facilities to which it can send ICRs and industry has a natural
reluctance to ``open its books'' for regulation development to an
Agency that also has enforcement oversight. However, I believe that EPA
and industry must both decide to work together in partnership if
realistic and scientifically supported regulatory decisions are to be
made. Without these partnerships, I believe there will be gaps in
knowledge (e.g., in data exchange, facility operations, or other
factors where information and data exists but may not find their way
into the risk assessment process). Where EPA has not used the best
information available as a basis for its decisions, it is highly likely
that legal remedies will be sought. It is clearly more effective to
have a cooperative and well-informed process rather than a distrustful
one where the best available information is shared and dissected during
legal proceedings.
Question 6a. In your written testimony, you indicated that it is
not in the Nation's best economic interest to force needless
expenditures when residual risks are not excessive.
What do you consider to be excessive?
Response. Because I do not believe there is any ``bright line''
which defines an excessive risk, there is no one answer to this
question. Risk must be looked at in its totality and include
consideration of the type of adverse effect (e.g., cancer or non-
cancer, chronic or acute), the affected human populations (ranging from
a few individuals to a large population), the existence of ecological
effects, and other important factors. Each situation must be considered
individually and appropriate risk management decisions made using all
available information. Only in that context can a decision be made as
to whether a risk is excessive or not.
Question 6b. Are you referring to the cancer risks to the maximally
exposed individual or some other test?
Response. I noted in my testimony how EPA focused initially only on
cancer risks to the maximally exposed individual. However, there are
many other adverse health and ecological effects, and much more of the
population is exposed than just that person maximally exposed. All of
my testimony assumes that proper risk assessments must look at all
potentially adverse effects and the total exposed population.
__________
Statement of Dr. Morton Lippmann, Professor, Department of
Environmental Medicine, New York University School of Medicine and
Interim Chair, U.S. Environmental Protection Agency Science Advisory
Board
Mr. Chairman and members of the committee, I appreciate the
opportunity to testify on the scientific basis for, current limitations
of, and opportunities for future improvements in quantitative risk
assessment as a tool for environmental risk management. I'd like to
share with you some what I've gleaned from my service on EPA's Science
Advisory Board and as a member of the National Research Council's
Committee on Research and Peer Review in EPA.
defining and characterizing environmental risks and benefits
In theory, it should be possible to engage in rational comparative
risk analyses as a means of selecting cost-effective means for the
protection of the public's health and our common natural environment.
At present, however, the available knowledge base is generally too
limited to adequately guide risk-based actions by legislators and/or by
governmental agencies to protect and/or improve the environment. What
we need is a strategic plan to extend the range and depth of knowledge
for risk assessment, taking advantage of the scientific and technical
capabilities that are advancing so remarkably in the current era. We
also need an effective means of organizing that knowledge, effectively
communicating it to appropriate stakeholders, and we need processes for
the identification of socially acceptable means of risk-based
intervention to prevent, ameliorate, and/or to reverse environmental
degradation by more efficient and effective means.
In other words, we must be careful to distinguish between what
capabilities we can hope for and expect to be available in the not-too-
distant future, and what current tools can provide for us now. We must
also recognize that advancement and refinement of our tools for
quantitatively determining risks and benefits will not just improve on
their own. New research resources will need to be invested to further
develop and hone these tools. With appropriate investments in risk
assessment research, we can look forward to ever increasing
capabilities for more quantitative risk assessments, more definitive
comparative risk assessments, more definitive benefit-cost analyses,
and more efficient and effective risk management options.
In recent years, as a result of my chairmanship of various EPA
Science Advisory Board (SAB) Committees (Clean Air Scientific Advisory
Committee, Human Exposure Committee, Secondary Data Use Committee,
Environmental Tobacco Smoke (ETS) Risk Assessment Review Committee,
Dioxin Risk Assessment Review Committee), and as my membership on the
Steering Committees for the SAB Reports on Future Risk, Reducing Risk,
and Beyond the Horizon, my continuing participation in the SAB Advisory
Council on Clean Air Act Compliance Analysis (Council) reviews of the
Benefits and Costs of the Clean Air Act, and my contributions to the
recently completed National Research Council's Report on
``Strengthening Science and Peer Review at the EPA'', I have become
quite familiar with the capabilities and limitations of the predictive
models and of environmental and epidemiological data bases available at
EPA for risk and benefits assessments. In this regard, I have come to
recognize that EPA is heavily dependent on its predictive models for
exposure and risk estimation. Unfortunately, many of these models have
not yet been fully validated. The adequacy of EPA's models for
quantitative risk assessment is discussed in greater detail in the
testimony of Dr. Philip Hopke in Panel 3.
This hearing is focused on the capabilities and limitations of
current knowledge and technical means of comparative risk assessment
for guiding new legislative mandates, societal choices, and individual
decisions based on risk avoidance. In my remarks, I will focus on
health risks associated with exposures to airborne chemicals and
mixtures thereof in our communities.
In order to determine the extent of any health risk existing among
the members of the population of concern resulting from the inhalation
of airborne chemicals we need to know: (1) the distribution of the
concentration of the agent in the air and, for airborne particulate
matter (PM), the distribution of particle sizes; and (2) the unit risk
factor, i.e., the number of cases and/or the extent of the adverse
effects associated with a unit of exposure. For more sophisticated
analyses, we may also need to know more about the population of
concern, such as the distribution of ages, pre-existing diseases, pre-
disposing factors for illness, such as cigarette smoking, dietary
deficiencies or excesses, etc.
When basic information on ambient levels and unit risks is
available, it is relatively straightforward to compute, tabulate, and
compare the risks associated with the different chemicals in our
community air. However, based on the experience gained in the Council
Review of the Benefits and Costs of the Clean Air Act, such direct
comparisons can, in practice, only be made with any quantitative
reality for a handful of chemicals, i.e., the so-called criteria
pollutants, whose ambient air levels are routinely monitored and for
which directly measured human exposure-response relationships have been
developed. For hundreds of other airborne chemicals, known collectively
as hazardous air pollutants (HAPs), a.k.a. air toxics, there are
neither extensive ambient air concentration data nor unit risk factors
that do not intentionally err on the side of safety. This disparity has
resulted from the different control philosophies built into the Clean
Air Act (CAA) and maintained by the EPA as a part of its regulatory
strategy. The rationale for the distinction is that criteria pollutants
come from numerous and widespread sources, have relatively uniform
concentrations across an airshed, require statewide and/or regional air
inventories and control strategies for source categories (motor
vehicles, space heating, power production, etc.) focused on the
attainment of air quality standards (concentration limits) whose
attainment provides protection to the public health with an adequate
margin of safety. There is also a long history of routine, mostly daily
measurements of criteria pollutant concentrations throughout the
country.
By contrast, HAPs sources are far fewer in number and are
considered to be definable point sources at fixed locations. Downwind
concentrations are highly variable, and generally drop rapidly with
distance from the source due to dilution into cleaner, background air.
The national emission standards for hazardous air pollutants (NESHAPs)
are based on technologically based source controls and are intended to
limit facility fenceline air concentrations to those that would not
cause an adverse health effect to the (most exposed) individual living
at the fenceline. Also, until quite recently, there has been no program
for routine measurements of air toxics in our communities.
Most of the unit risk factors for air toxics are based on cancer as
the health effect of primary concern. In these studies, and in studies
to assess noncancer effects the data are most often derived from
controlled exposures in laboratory animals at maximally tolerated
levels of exposure. The translation of the results of these studies to
unit risk factors relevant to humans exposed at much, much lower levels
in the environment is inherently uncertain, and is approached
conservatively, following the model pioneered for food and drug safety
beginning in the 1930's by the Food and Drug Administration (FDA). The
resulting unit risk factors are generally based on an assumption of no
threshold and a linear extrapolation to zero risk at zero dose. They
are generally described in terms of being 95 percent upper bound
confidence limits, but this descriptor is undoubtedly conservative in
itself.
When these conservative unit risk factors are used for the
prediction of the consequences of human exposures, they are multiplied
by estimates of predicted ambient air concentrations which are,
themselves, in the almost universal absence of air concentration
measurements, almost certainly upper bound estimates from pollutant
dispersion models that apply to the most highly exposed individuals in
the community.
The resulting estimates of health risk are therefore highly
conservative upper bound levels. Thus, they are inherently incompatible
with population impacts estimated for the more widely dispersed
criteria pollutants. The margins of safety for criteria pollutants are
generally less than a factor of two, rather than the multiple orders of
magnitude of safety factors built into the risk assessments for air
toxics.
The same considerations discussed above, i.e., the limitation of
available knowledge for determining realistic unit risk levels has also
made it virtually impossible for EPA to meet its Congressional mandate
to determine residual risks after the imposition of technology-based
controls of air toxics, as discussed in greater detail in the testimony
provided to this Hearing by Dr. Philip Hopke in Panel No. 3.
The highly conservative nature of unit risk factors for air toxics
was well illustrated by a calculation made during work done for EPA
during the preparation of the Congressionally mandated report on the
Benefits and Costs of the Clean Air Act: 1970-1990. It was determined
that the imposition of the vinyl chloride NESHAP had prevented 6,000
cases of cancer. Vinyl chloride is a known human carcinogen that
produced a very rare tumor (angiosarcoma of the liver) in highly
exposed vinyl chloride production workers. The handful of cancers
observed among these workers was not large in relation to overall
cancer incidence, but this particular tumor was such a rare one that
even the first few cases that were observed among a group of vinyl
chloride production workers were sufficient to establish a causal
relation. Since the calculated cancer incidence reduction was
considerably larger than the historic incidence level for this cancer,
it was obvious that the benefit claimed for the imposition of the
NESHAP was grossly exaggerated.
The lack of any alternative quantitative approach to the
quantitative estimation of health effects due to exposure to air toxics
has left EPA with no viable option for the realistic estimation of
population impacts. With prodding from the SAB Council, the Agency has
recognized the need to develop one. That effort is now underway,
through EPA and SAB sponsorship of a first Workshop (June 22 and 23,
2000) in a series designed to address the issue directly. Extension of
this initiative would lead to the development of a capability to
produce more unbiased predictions of the health consequences of HAPs
exposures for benefits assessments.
In the meantime, EPA needs to undertake a public education program
about the essential nature of its widely distributed and commonly used
unit risk factors. This is especially urgent in view of its recent
initiative to support a nationwide network of routine air quality
monitoring stations for a large number of representative air toxics.
Pilot studies have already demonstrated the multiplication of measured
levels times the current unit risk factors suggest that urban dwellers
are at lifetime risks of excess cancer greater than one in a thousand.
Exaggeration of risks pertaining to the general public could produce a
considerable problem for EPA in its communication to the public, and
could lead to a loss in its credibility.
Comparative risk analysis, as currently practiced, has other
inherent limitations as well. Even when we can reasonably and reliably
estimate the exposure-related numbers of cases of premature mortality,
hospital admissions, other uses of medical, clinical and pharmaceutical
drug resources, lost time from work or school, reduced physiological
and functional capacities, we face daunting societal equity and
valuation challenges in inter-comparing numbers of incident cases of
quite variable clinical severity and psychological impacts. For
carcinogenic agents, it has become customary to expect regulations to
be effective in limiting the risks of lifetime exposures to no more
than one-in-ten thousand and often to less than one-in-a-million. For
less dreaded diseases that also reduce lifespan, such as chronic
obstructive pulmonary disease and heart attack, which also are
exacerabated by air pollutant exposures, a much higher risk level has
been considered acceptable by regulators and the public. By contrast,
economists do not make such a drastic distinction. EPA's recent White
Paper on the economic valuation of cancer mortality concluded that the
economic literature did not provide a basis for a greater benefit for a
prevented cancer death than for other causes of premature deaths.
The National Research Council (NRC) committee that issued its
report on ``Strengthening Science and Peer Review at EPA'' was well
aware of the current limitations of comparative risk assessment when it
concluded that:
Scientific knowledge and technical information are essential
for determining which environmental problems pose important
risks to human health, ecosystems, the quality of life, and the
economy. We need scientific information to avoid wastefully
targeting inconsequential risks while ignoring greater risks.
We need such information to reduce uncertainties in
environmental decisionmaking and to help develop cost-effective
strategies to reduce risk. We need science to help identify
emerging and future environmental problems and to prepare for
the inevitable surprises.
The quotation above provides a good part of the background that led
to the key recommendations of the NRC Report regarding the management
and use of science in regulatory programs, and the need for and Agency
management of its own research program to fill key gaps in our current
abilities to quantify risks. Focus on this need should be a priority
for the recommended position of Deputy Administrator for Science in
EPA. This individual should have the background and judgment essential
to ensure that current risk-related knowledge is appropriately used to
develop, describe, and guide scientific input into regulations, and to
ensure communication of the knowledge gained by the regulatory programs
in terms of further research needs for risk assessment and risk
management. The Deputy Administrator for Science could also provide
oversight for EPA's new Office of Information in regard to facilitating
more data entry into and wider access to and usage of EPA's
environmental monitoring data sets that are now seldom used for
secondary data analysis and/or model validation.
The NRC Report also concluded that research on risk assessment and
risk management was not only needed, but needed to be conducted by EPA,
since no other Federal agency had the mandate, need, or desire to
conduct such research.
Finally, it should be recognized that research on risk assessment
and risk management needs to be a long-term core component of EPA's
research program. Core research needs stability, a feature which has
not been a hallmark of EPA's Office of Research and Development (ORD).
Tenure for a Presidentially selected and Senate confirmed Assistant
Administrator (AA) for ORD has been 3 years or less, and Acting AAs for
ORD have occupied the position for about half of the whole history of
EPA. Thus, the NRC Report recommended that the position be changed to a
6-year term-appointment, with the AA selected for expertise in both
science and research management. This change would help to ensure the
primacy of a longer term view of research goals focused on EPA's unique
role as a regulatory agency that relies strongly on sound science to
guide the formulation of its standards, guidelines, and cost-effective
risk management.
The differences in EPA's current abilities to make estimates of
health risks for air toxics on the one hand and estimates of benefits
resulting from its successes in source controls on the other, while
notable and unfortunate, are remediable, and the research needed to
overcome the current deficiencies should be given a high priority. The
ORD has come a long way in recent years in terms of its development and
updates on its strategic plan, its inventory of science activities and
capabilities through the Agency, its closer coordination with research
programs in NIH, NSF, and CDC, and its shift of resources toward an
extramural grant program in which EPA's research needs are met, in
part, through individual investigator-initiated proposals that address
critical information needs identified in Requests for Applications. It
will also soon occupy new state-of-the-art research facilities in
Research Triangle Park, NC that will enhance its capabilities.
In summary, our current abilities to determine residual risks of
air toxics and to compare risks quantitatively are quite limited by key
gaps in knowledge, and by reliance on unvalidated predictive models for
exposure and for dose-response. A major part of the problem is the
existence of two very different cultures of risk assessment: (1) for
carcinogens; and (2) for other toxicants. Carcinogen risk assessments
seldom have been based on relevant data on either low-dose exposure on
human exposure-response data at concentrations anywhere near ambient
levels. They require high-dose to low-dose extrapolations and generally
animal-to-human extrapolations as well, using unvalidated predictive
models. In the face of such a high degree of uncertainty in the output
of the models, conservative assumptions are used to ensure that potency
and exposures are not underestimated. Thus, yields of risk estimates
are almost always far higher than the real risks. Such risk estimates
cannot be fairly compared to the risks associated with criteria air
pollutants, which are determined largely from the product of measured
air pollutant concentrations and measured responses among humans
exposed to either ambient air or to controlled exposures in chambers.
Fair comparisons can only be done within the separate categories of
pollutants.
Comparative risk assessment is an idea whose time is coming, and if
EPA is provided with appropriate research resources to harness the new
technical approaches and sophisticated research tools now emerging to
fill in key knowledge gaps, it can make comparative risk assessment
more useful and feasible in the not-too-distant future. If the
recommendations in the NRC ``Strengthening Science at EPA'' report are
adopted, the prospects for such advances would be greatly improved. In
the meantime, the resources now dedicated to performing comparative
risk assessments would be more productively employed if redirected to
improving the technology for quantitative risk assessment and for
filling key knowledge gaps that have been identified in the analyses
already performed.
Dr. Hopke, in his testimony in the next panel will address the
major knowledge gaps limiting EPA's ability to perform the residual
risk assessments mandated for HAPs in the 1990 Clean Air Act
Amendments, even for an industrial sector like secondary lead smelters
that is relatively data-rich. In my view, we should celebrate the
success of the application of the best available technology approach in
greatly reducing emissions and ambient concentrations of air toxics and
limit the use of quantitative risk analyses of residual risks to the
screening out of deminimus risks.
Finally, I encourage the Congress to implement the legislative
changes needed for the creation of the new position of Deputy
Administrator for Science in EPA and for transforming the position of
Assistant Administrator for Research and Development in EPA to a 6-year
term appointment. These changes will help ensure institutional
stability and a more long-term framework for core research. I also
encourage Congress to consider explicitly giving EPA a mission
statement that includes the performance of a long-term research program
as a means of enhancing its capabilities for effective and efficient
stewardship of its environmental responsibilities.
In closing, I want to thank the committee for inviting me to
testify on these important issues related to scientific aspects of
environmental risks and on opportunities to improve the practice and
utility of risk assessment and risk management.
______
Dr. Morton Lippmann, Acting Chair,
Science Advisory Board (1400A),
U.S. Environmental Protection Agency,
Washington, DC.
Dear Dr. Lippmann: Thank you for your letter of May 19, 2000,
transmitting the Science Advisory Board (SAB) Advisory on the Draft
Agency Case Study Analysis of the Residual Risk of Secondary Lead
Smelters (EPA-SAB-EC-ADV-00-005). During the review of the Residual
Risk Report to Congress in August 1998, the Science Advisory Board
requested that the Environmental Protection Agency (EPA) provide an
example residual risk assessment for its evaluation. We submitted our
draft assessment of the secondary lead smelter source category and
would now like to respond to your letter transmitting the SAB advisory
for this case study.
The purpose of seeking an SAB advisory was to get feedback on the
methodologies EPA will use to assess residual risks and the application
of those methods to a specific source category. We asked the SAB to
comment on: (1) the appropriateness of the methods used, given the
currently available methods; and (2) the appropriateness of the
application of those methods. We sought SAB feedback early in our
residual risk assessment process in order to be able to apply the
advice received to other risk assessments under the residual risk
program which, due to statutory requirements, needed to be started
soon.
This draft case study does not include all risk assessment
components needed to make a regulatory decision under the Residual Risk
program (e.g., an assessment of population risks). Because of this, we
agree with the SAB that peer review of the final complete assessment is
needed. We intend to seek such a review in 2001.
We are pleased that the reviewers recognize that methods used in
this case study assessment are consistent with the methods described in
the Residual Risk Report to Congress, that the assumptions used are
consistent with current methods and practice, and that the models used
for the air pathway are the most appropriate for the task. Our response
to additional comments and recommendations highlighted in your review
are enclosed.
This SAB advisory will help us design the final iteration of the
secondary lead smelter risk assessment. We are also applying your
advice to the other risk assessments we are required to conduct under
the residual risk program. Thank you for your assistance.
Sincerely,
Carol M. Browner.
______
Attachment
Responses by Environmental Protection Agency to Additional Comments
from the Science Advisory Board
Comment. Population risk estimates are lacking from the case study.
Response. EPA will include an assessment of population risks in the
final iteration of the assessment, following the method we outlined in
the draft case study.
Comment. Ecological screen is adequate but refined ecological risk
assessment is lacking, as are the methodologies.
Response. EPA did not present a more refined ecological risk
assessment in the draft case study, as we have not yet completed
development of a refined ecological risk assessment methodology for the
residual risk program. We are working to develop a refined methodology
and will use our most current methodology in the final iteration of the
secondary lead smelter risk assessment.
Comment. Uncertainty and variability analysis should be fully
integrated into all phases of the assessment, not just an auxiliary
analysis after the deterministic assessment.
Response. EPA agrees with the Science Advisory Board that
integrating uncertainty and variability analysis into the overall
assessment rather than conducting it as an add-on analysis of the
deterministic results is important. EPA is incorporating that advice
into our assessments. We are conducting uncertainty and variability
analyses at each phase of the assessment to determine how assumptions
are supported by the data, and what the implications are for each
assumption. While there is no consensus among experts on a methodology
to conduct uncertainty and variability analysis, we will continue to
seek out experts and use methods which are appropriate to the task.
Comment. The model used for multimedia fate, transport and multi-
pathway exposure assessment, the Indirect Exposure Methodology (IEM)
has several limitations, and has not been sufficiently evaluated.
Results should be viewed with informed caution and results ground-
truthed against available data. TRIM is seen as major improvement.
Response. EPA recognizes the importance of evaluating models and
ground-truthing the results of the models we use in support of
regulation. EPA intends to evaluate model inputs and ground-truth
results to the extent data are available. (Data were not readily
available on the four facilities we evaluated but may be available for
others; for other source categories, such information maybe more (or
less) available.). EPA will ensure that the limitations and
uncertainties of IEM outlined by the SAB are clearly articulated to the
risk managers. We agree that TRIM will generally be an improvement
relative to IEM. We look forward to further comments on our approach to
multimedia modeling in the peer review of the completed assessment.
Comment. There is insufficient explanation about the interface
between risk assessment and risk management; without this context it is
difficult to adequately review the assessment.
Response. EPA will explain more about the Residual Risk program
mandate and its approach to risk management in the final iteration of
the assessment. We will specifically describe how the risk assessment
feeds into the risk management process.
Comment. There is incomplete toxicity data on some HAPs and the
data in Integrated Risk Information System (IRIS) may be seriously out
of date for others.
Response. EPA is not limited to using data within IRIS. EPA has
identified a number of additional peer reviewed data sources, from
which relevant information can be obtained. These data sources include
peer reviewed data bases developed by the Agency for Toxic Substances
and Disease Registry and California EPA. The SAB concurred with our use
of the data from these sources, which allow EPA to both assess HAPs for
which assessments are not currently available on IRIS and to consider
information from other sources that may be more current and relevant
than that available on IRIS. HAPs with no assessments on IRIS or
elsewhere receive priority in our yearly list of IRIS assessment
starts. Additionally, we are carefully considering the SAB's
recommendation to develop interim methods for assessing HAPs without
available assessments.
______
Responses by Morton Lippman to Additional Questions from Senator Smith
Question 1. In your testimony, you stated that ``comparative risk
assessment'' is an idea whose time is coming. For this to happen,
according to your testimony, EPA has to harness the new technical
approaches and research tools to fill in key knowledge gaps. Why is it,
in your opinion, that EPA has not taken a more aggressive approach to
fill those gaps?
Response. The EPA's research program has developed and refined a
research. strategy in recent years that includes an increased emphasis
on long range generic needs such as quantitative risk assessment. Also,
it is about to open its new state-of-the-art research facility in
Research Triangle Park, NC, which will give it the capacity for
applying new research tools. The basic problems that have limited EPA's
progress in addressing the knowledge gaps in this area have been
reviewed recently by the National Research Council in their report
entitled ``Strengthening Science at the U.S. Environmental Protection
Agency''. These problems include:
Lack of a core focus on the art and science of risk
assessment. The NRC report stated that ``The Assessment Center should
focus on being a research organization dedicated to advancing the State
of practice in risk assessment, not a performer of individual risk
assessments that could be done by EPA's regulatory offices'' (NRC
Report: p. 85).
The NRC Report noted the absence of published strategic
and management plans for the ORD Laboratories and Centers. Strategic
planning has, so far, been a ``top-down'' effort that is only partially
effective. The NRC panel expressed concern that ORD has not yet
provided adequate delegation of opportunities for leadership and
accountability throughout the organization (NRC Report: p. 68).
Staff Resources. The NRC reported noted the aging of the
ORD staff and the Agency's difficulties, in the face of periodic job
freezes and personnel ceilings, in recruiting new talent with
appropriate background and training for new challenges.
Funding. ORD capacity to meet new scientific challenges is
constrained by living within an overall budget that is essentially
flat, at best, in terms of purchasing power, and strained, in terms of
flexibility, by an increasing level of earmarks for projects that have
not been appropriately peer-reviewed.
The NRC Panel's recommendations, if implemented, could greatly help
EPA to better address these problems. For example, a principal
responsibility of the new Deputy Administrator for Science and
Technology would be to ``Ensure that the most important scientific
issues facing EPA are identified and defined, including those embedded
in major policy or regulatory proposals'' (NRC Report: p. 130).
The NRC Panel's recommendation that ORD make a concerted effort to
give its research managers a high degree of flexibility and
accountability (NRC Report:
p. 133) could empower the director of the Assessment Center in ORD to
mount a concerted and sustained effort to create and manage a core
research program on the art and science of risk assessment as part of
the Center's own strategic plan.
Question 2. You testified that EPA overestimates health risk for
air toxics. Exaggerating risk when managing environmental programs is
counterproductive and a disservice to the public. Conservative
assessments have a place, but consistent excessive conservatism is
misleading. Resources that could be used to address neglected
environmental problems would instead be used to address problems whose
risks are exaggerated. When there are critical data gaps, and obsolete
analytical tools, the effectiveness of programs and progress cannot be
measured objectively. Please explain what the SAB is doing to ensure
that EPA understands the significance of the problems you identified.
Response. EPA has established Risk Assessment Guidelines that have
been reviewed and endorsed by SAB. These Guidelines have been
recognized as having a conservative bias by both EPA and SAB, i.e., in
the face of uncertainties involved in having to rely on the limited
data bases in the literature, they have incorporated reliance on
substantial margins of safety. The objective has been to be protective
of public health. Furthermore, the more limited the data base, the
greater the overall margin of safety tends to be. In fact, the Food
Quality Protection Act has mandated that when adequate data
establishing that children are not more sensitive than adults, then an
additional tenfold safety factor be used in assessing risks related to
the food supply.
The problem of excessive conservatism that you address in the above
listed question arises when the EPA risk assessors believe that they
have no other option than to use reference doses or reference
concentrations and their established technique for modelling exposures
(that are also inherently conservative) to: (1) develop quantitative
estimates of risks; or (2) to compare the various risks to public
health caused by exposures to environmental chemicals. They do not, and
in reality cannot, know how conservative their calculated risks really
are in each case. The problem is compounded when comparing risks using
risk coefficients of varying ages prepared under various historic
versions of the Risk Assessment Guidelines.
SAB has recently taken several initiatives to call this problem to
the attention of EPA. Our Advisory on the USEPA's Draft Case Study
Analysis of the Residual Risk of Secondary Lead Smelters (EPA-SAB-EC-
ADV-00-005) was dated May 2000, and our followup letter to the
Administrator (Executive Committee Commentary on Residual Risk
Program--EPA-SAB-ECCOM-00-005, dated July 25, 2000), put the concerns
we had about this issue in a broader context. (A copy of this brief
letter Commentary is attached.) Another example is the initiative taken
by the SAB's Advisory Council on Clean Air Act Compliance Analysis
(Council), in cooperation with EPA, to conduct multidisciplinary
Workshops focused on the development of techniques for establishing
best estimates of human exposures and risk coefficients that can be
used to obtain more realistic health benefits for benefit-cost analyses
(EPA-SAB-COUNCIL-ADV-00001, dated Oct. 29, 1999). In its advisory role
on the performance of both the 1970-1990 retrospective analysis and the
1990-2010 prospective analysis of the benefits and costs of the Clean
Air Act performed by EPA, the Council agreed that substantial health
benefits accrue to controls on criteria pollutants, most notably for
controls on particulate matter and lead, where credible risk factors
and population exposures are well established. On the other hand, such
benefits could not be established for the controls imposed on the
emissions of air toxics. The first Workshop, focused on Benefits of
Reductions in Exposure to Hazardous Air Pollutants: Developing Best
Estimates of Dose-Response Functions, was held on June 22 and 23, 2000
The second Workshop, focused on the Distribution of Human Exposures, is
planned for early next year. Through these Workshops, the groundwork is
being laid for what could become a new and more realistic paradigm for
quantitative risk assessment. This is what I had in mind when I stated
that ``comparative risk assessment is an idea whose time is coming.
Question 3. You testified that a major part of the problem with the
current EPA risk assessment stems from having 2 very different cultures
of risk assessment: (1) for carcinogens and (2) for other toxicants.
Please describe what SAB is doing to remedy this problem.
Response. My response to this question can be found in my response
to Question 2, in terms of the SAB advisories and commentaries cited
therein.
______
U.S. Environmental Protection Agency,
Washington, DC, July 25, 2000.
EPA-SAB-EC-COM-00-005
Hon. Carol M. Browner, Administrator,
U.S. Environmental Protection Agency,
Washington, DC.
Subject: Executive Committee Commentary on Residual Risk Program
Dear Ms. Browner: The Executive Committee (EC) of the Science
Advisory Board (SAB) is writing to alert you to potentially significant
issues arising from with the Agency's efforts to implement the residual
risk requirements of the Clean Air Act Amendments of 1990.
In 1998, the SAB sent you a report (EPA-SAB-EC-98-013) on its
review the Agency's Report to Congress on the methodology to be used in
assessing the residual risks associated with the post-Maximum
Achievable Control Technology (MACT) emissions of hazardous air
pollutants (HAPs) from 174 source categories across the country. The
Board endorsed the Agency's plan but identified the need to see the
methodology applied to a specific case in order to determine whether
the methodology was viable in practice, as well as in principle.
This spring, the SAB reviewed an Agency interim work product that
indicates how the Office of Air and Radiation (OAR) plans to implement
this methodology in practice. The results of that review were sent to
you in May in the ``Advisory on the USEPA's Draft Case Study of the
Residual Risks of Secondary Lead Smelters'' (EPA-SAB-ECADV-00-005). In
short, the Board found that the Agency has made a good faith start in
using the methodology to assess the residual risks from this source
category but went on to cite significant scientific problems that raise
serious concerns about the potential for the Residual Risk Program, as
currently conceived, to successfully achieve its goals. In particular,
we understand that secondary lead smelters were selected as the first
HAPs source category for the residual risk exercise, in part, because
it contains a limited number (24) of facilities, and because it has a
large monitoring data base, compared to most of the other 173 source
categories. In light of the relatively favorable knowledge base for
this case study and the quite limited success that it has achieved to
date, the SAB believes that the large number of data-poor categories
will prove to be even more intractable to this type of analysis than
the secondary lead smelter category has been shown to be to date. In
summary, it is not clear that scientific analysis will be able to
generate the type of information envisioned in the CAAA. While
decisions can be made in the absence of such scientific information,
they will not be sufficiently precise for the intended purpose.
While our concerns may turn out to be ill-founded, we recommend
that the Agency and Congress seriously re-consider the current Clean
Air Act Amendments mandates and their implementation strategy that
depends on scientific analyses that will be resource-demanding, at a
minimum, and, quite possibly, impossible to carry out in a credible
manner.
In summary, while we certainly endorse the concept of science-based
decisionmaking at the Agency, we also recognize that no one is well
served by asking science to take on an impossible task.
We would look forward to meeting with Agency leaders and
Congressional personnel to discuss these concerns and what might be
done about them.
Sincerely,
Dr. Morton Lippmann,
Interim Chair,
Science Advisory Board.
______
U.S. Environmental Protection Agency, Science Advisory Board, Executive
Committee FY-2000
interim chair
Dr. Morton Lippmann, Professor, Nelson Institute of Environmental
Medicine, New York University School of Medicine, Tuxedo, NY
members
Dr. Henry A. Anderson, Chief Medical Officer, Wisconsin Division of
Public Health, Madison, WI
Dr. Richard J. Bull, MoBull Consulting, Inc., Kennewick, WA
Dr. Maureen L. Cropper, Principal Economist, DECRG, The World Bank,
Washington, DC
Dr. Kenneth W. Cummins, Senior Advisory Scientist, California
Cooperative Fishery Research Unit and Adjunct Professor, Fisheries
Department, Humboldt State University, Arcata, CA
Dr. Linda Greer, Senior Scientist, Natural Resources Defense
Council, Washington, DC
Dr. Hilary I. Inyang, University Professor and director, Center for
Environmental Engineering, Science and Technology (CEEST), University
of Massachusetts Lowell, Lowell, MA
Dr. Janet A. Johnson, Senior Radiation Scientist, Shepherd Miller,
Inc., Fort Collins, CO
Dr. Roger E. Kasperson, University professor and director, The
George Perkins Marsh Institute, Clark University, Worcester, MA
Dr. Joe L. Mauderly, director & senior scientist, Lovelace
Respiratory Research Institute, Albuquerque, NM
Dr. M. Granger Morgan, Head, Department of Engineering & Public
Policy, Carnegie Mellon University, Pittsburgh, PA
Dr. William Randall Seeker, Senior Vice President, General Electric
Energy and Environmental Research Corp., Irvine, CA
Dr. William H. Smith, Professor of Forest Biology, Yale University,
New Haven, CT
Dr. Robert N. Stavins, Albert Pratt Professor of Business and
Government, Faculty Chair, Environment and Natural Resources Program,
John F. Kennedy School of Government, Harvard University, Cambridge, MA
Dr. Mark J. Utell, Professor of Medicine and Environmental
Medicine, University of Rochester Medical Center, Rochester, NY
Dr. Terry F. Young, Senior Consulting Scientist, Environmental
Defense Fund, Oakland, CA
liaison for childrens health protection advisory committee
Mr. J. Thomas Carrato, Assistant General Counsel, Regulatory
Affairs, Monsanto Company, St. Louis, MO
liaison for science advisory panel
Dr. Ronald Kendall, director & professor, The Institute of
Environmental & Human Health, Texas Tech University/Texas Tech
University Health Sciences Center, Lubbock, TX
liaison for ord board of scientific counselors
Dr. Jerald L. Schnoor, Professor of Civil Environmental
Engineering, Iowa University, Iowa City, IA
science advisory board staff
Dr. Donald G. Barnes, Staff Director/Designated Federal Officer,
Environmental Protection Agency, Science Advisory Board (1400A),1200
Pennsylvania Avenue, NW, Washington, DC 20460
Ms. Priscilla Y. Tillery-Gadson, Program Specialist, Environmental
Protection Agency, Science Advisory Board (1400A),1200 Pennsylvania
Avenue, NW, Washington, DC 20460
Ms. Betty B. Fortune, Office Assistant, Environmental Protection
Agency, Science Advisory Board (1400A),1200 Pennsylvania Avenue, NW,
Washington, DC 20460
notice
This report has been written as part of the activities of the
Science Advisory Board, a public advisory group providing extramural
scientific information and advice to the Administrator and other
officials of the Environmental Protection Agency. The Board is
structured to provide balanced, expert assessment of scientific matters
related to problems facing the Agency. This report has not been
reviewed for approval by the Agency and, hence, the contents of this
report do not necessarily represent the views and policies of the
Environmental Protection Agency, nor of other agencies in the executive
branch of the Federal Government, nor does mention of trade names or
commercial products constitute a recommendation for use.
Distribution and Availability.--This Science Advisory Board report
is provided to the EPA Administrator, senior Agency management,
appropriate program staff, interested members of the public, and is
posted on the SAB website (www.epa.gov/sab). Information on its
availability is also provided in the SAB's monthly newsletter
(Happenings at the Science Advisory Board). Additional copies and
further information are available from the SAB Staff.
______
Responses by Morton Lippmann to Additional Questions from
Senator Baucus
Question 1. In your testimony, you say that, at present, ``the
availability knowledge base is generally too limited to adequately
guide risk-based actions by legislators and/or by government
agencies.'' In the context of a national comparative risk assessment to
define EPA's budget and regulatory priorities, do you mean that it is
currently not possible to conduct a comparative risk assessment for
such a purpose?
Response. If your question refers to a comprehensive comparison,
then the answer is yes. However, it is important to recognize that
reasonably realistic assessments are possible. For example, it is
generally possible to distinguish the truly large risks from those that
are considerably smaller. Also, assessments have been made for the
category of criteria air pollutants. For these pollutants, appropriate
investments in exposure, risk, and benefits analyses have been made by
EPA, and the results are evident in the reports on the Benefits and
Costs of the Clean Air Act. However, such investments have not been
made for the category of air toxics and, without the data bases that
flow from such investments, credible comparative risk assessments are
not possible.
At the same time substantial impediments will remain that cannot be
``solved'' by science. For example, social values--not science--must
guide how one weighs health vs. ecologic risk and risks to children vs.
risks to adults.
Question 2. Since it is basic to risk assessment, what is the
appropriate way for the committee to decide what is ``good science''
and what is not?
Response. Science is a method of inquiry that generates data that
are available in the intellectual market place for all interested
parties to buy or not to buy. Its reliability and appropriate usage in
scientific analyses is policed by the process of peer-review which,
while not infallible, is generally regraded as a stamp of credibility.
The usage of scientific information in the formulation of environmental
risk assessments, standards, and benefits analyses is the issue here.
The basic question is: Has the analysis of scientific data base in the
peer-reviewed literature been comprehensive and objective, and has that
data base been used in a credible and appropriate manner? Here also,
appropriate peer review is the key to the usage of scientific
information for ``good'' or ``bad'' ends. The Science Advisory Board
(SAB) has long been a reliable arbiter of such usage, but it cannot
review all such usage in an Agency as large and complex as EPA.
Therefore, it is fortunate that EPA has, in recent years, made
considerable progress in organizing and using other appropriate
mechanisms for scientific peer review of its products. This encouraging
progress was noted by the National Research Council (NRC) in its recent
report ``Strengthening Science at the U.S. Environmental Protection
Agency''. Adoption of the recommendation in the NRC report for the
creation of the position of Deputy Administrator for Science and
Technology at EPA would further advance the Agency's ability to defend
its ``good'' usage of science.
Question 3. Clearly, science is needed to inform decisionmaking.
But, in your opinion, is there also a role for non-scientific
considerations, such as societal values, in informing decisions on the
risk rankings and priorities that are developed from a comparative risk
assessment?
Response. Clearly, the simple answer to your question is yes. All
risks are not of equal consequences, and risk management options may
involve other risks than the one being controlled. Consideration can
and should be given to balancing benefits and costs. The SAB has
recognized that policy decisions, which must recognize societal factors
in addition to the physical and biological sciences, need to be made by
properly constituted authorities. The SAB has been expanding its range
of expertise by involving social scientists, in order to incorporate
the data and technique of their fields to inform the decisionmaking
process. At the same time, the SAB has been careful not to cross the
science-policy interface in its recommendations to the Agency.
Question 4. In your oral testimony, you talked about the
conservative nature of EPA's risk assessments for HAPs. I would like to
clarify my understanding of your comments on this point. You appeared
to indicate that the reason that EPA uses conservative assumptions,
such as safety factors, is because as we learn more about HAPs in the
future it could be found that some of the chemicals are as toxic as
predicted by the risk assessments made using the current models.
Therefore, the convention is that, in order not to underestimate the
potential risk associated with these HAPs, conservative assumptions are
applied to risk estimates of all HAPs. Is this a correct interpretation
of your testimony on this point?
Response. Yes.
Question 5. In the panel on residual risk, many concerns were
expressed about EPA's draft case study on residual risk assessment for
secondary lead smelters. This seems to be the fate of many, if not
most, risk assessments. In fact, it often seems that every time a risk
assessment is done these days--whether it is to regulate a
environmental problem, update a standard, or better understand a
problem such as climate change--it is greeted with an extremely high
level of controversy. Given this, how realistic do you think it is for
us to consider doing a comparative risk assessment that would set EPA's
budget priorities--something that would require a separate risk
assessment for each of the Nation's environmental problems--but still
avoid controversies over each and every risk assessment the priorities
are based on?
Response. As long as the different stakeholders in our society
focus on their individual concerns about the impact of regulatory
decisions and processes they will engender controversy put pressure on
the Agency and Congress to support their view and, at times, bring
their concerns into the Courts. Quantitative risk assessments can only
inform, not resolve such controversies. When such risk assessments are
scientifically credible, as they mostly are for criteria air
pollutants, they are especially valuable. When they are highly
speculative, and heavily biased in a conservative direction, such as
those for air toxics, they are probably only useful in establishing
very low (de minimus) risk levels. Such usage is, however, often useful
for the many cases where conservatively estimated risks are, indeed,
very low. That is, if the admittedly over-estimated risks are low,
there is nothing to worry about.
Question 6. I would be interested in your thoughts on what problems
would likely be encountered, and how successful we would likely be, if
we attempted to perform a national comparative risk assessment in order
to set EPA's new budget and regulatory priorities.
Response. As noted above, I believe that comparative risk analyses,
when based on appropriately generated data, can help significantly in
the priority setting process. However, even with appropriate risk
estimates, there will still be difficult, value-based decisions to be
made.
For the balance of my response, I would like to broaden the issue
of EPA's budget.
First and foremost, I believe that EPA's budget for research and
development is far too low for the roles that ORD is expected to play
in providing the reliable and relevant data that are needed for the
protection of the environment and the public's health. Inadequate
funding hamstrings the ability of science to inform regulatory
decisions of enormous complexity and importance. The environmental
quality issues that impact public health and the environmental future
are more complex than they have ever been, but EPA and its ORD are
still focused largely on generating scientific and technical
information for the short-term regulatory agenda. As noted in the
recent NRC Report, the ORD budget has remained a small percentage of
EPA's overall budget and, furthermore, the options for its optimal
usage have been greatly reduced by the increasing proportion for
``earmarks''. In considering the structural changes for EPA recommended
by the NRC Report, i.e., the creation of a Deputy Administrator for
Science and Technology, and in making the Assistant Administrator for
ORD a 6-year term appointment, Congress should also consider giving the
EPA a more comprehensive and unified mission that includes a directive
to conduct both basic and applied environmental research, as well as a
program of environmental monitoring that can generate baseline and
trends data of the highest quality. Such data will be essential for the
more reliable health, ecological, and environmental quality risk
assessments that can truly and effectively inform legislative and
regulatory enforcement agendas.
Question 7. In your testimony related to residual risk, were you
stating that the residual risk program is addressing risks that are not
a problem, or when you look at the array of air pollution problems,
such as fine particulates, that these other problems should be a higher
priority for the Agency?
Response. Given current scientific capabilities for determining
residual risks in a meaningful way for 174 source categories and/or for
189 hazardous air pollutants, the current process will, in my opinion,
be overly expensive in terms of cost and a wasteful use of personnel
resources. Air toxics releases and exposures have been greatly reduced
in recent decades. Some of this progress was directly attributable to
the 1990 CAA mandate to apply best available control technology. Of
equal or greater importance has been the control of primary particulate
emissions and emissions of ozone and fine particle precursors for the
purpose of meeting the NAAQS for PM and ozone. Further emission
reductions can be anticipated as a result of the need to meet the 1997
NAAQS revisions for PM and ozone in many parts of the country in order
to comply with the new NAAQS, and to reduce the impact on the public's
health. Real risks associated with PM and ozone exposures that are
occurring at and even below the levels of the 1997 NAAQS are now well
established. Congress should revise its mandated timetable for residual
risk determinations if it desires the Agency to generate credible
state-of-the-art best estimates of low-level risks. If, on the other
hand, Congress is satisfied with rough screening risk assessments that
would identify the most plausible post--MACT risks, then the current
approach may suffice. However, more case studies would need to be
reviewed to evaluate the utility of such screening.
Question 8. I'm a little confused about where some opponents of
regulation might take your comments. You have talked about unvalidated
predictive models at EPA. I think you said that we have ``no viable
option for realistic estimation of population impacts'' due to air
toxics exposure. Could someone infer from what you are saying that you
don't believe that we should reduce air toxics emissions as
expeditiously as practicable?
Response. Someone could, and probably will, make such an inference,
which would be an unfortunate and unintended consequence of having such
comments on the public record. As noted in my response to your previous
question, there are serious health effects that can result from air
toxics emissions, at least via the role of air toxics emissions on
exposures to PM and ozone. These warrant continued and perhaps even
tighter control over air toxics emissions. It is also prudent to
acknowledge that some specific air toxics are likely to have their own
specific adverse effects on public health, even if we can't quantify
them reliably at this time with our current risk assessment methods.
Question 9. I believe you stated in your written testimony that we
should ``put off any great effort at quantitating [their] residual
risks until we have the ability to perform more realistic and credible
risk assessments.'' Senator Inhofe seemed to construe that to mean you
were advocating that we discontinue any regulatory efforts to reduce
residual risk for the foreseeable future, because the science of risk
assessment will always have significant quantitative uncertainties. Is
that interpretation of your position correct?
Response. No. The reasons for my negative response to this question
are provided in my response to your previous question.
Questions 10a and b. You indicated that ``yields of risk estimates
are almost always far higher than real risks.'' What is a ``real risk''
data point in that case? Are there any reliable studies confirming that
``yields of risk estimates are almost always far higher than real
risks?''
Response. I had two reasons for my perhaps too dogmatic statement
cited above. First, I participated in the Council review of the air
toxics analyses performed for EPA during the preparation of EPA's
retrospective analyses of the Costs and Benefits of the Clean Air Act.
Fourteen air toxics were reviewed and for two of them, i.e., vinyl
chloride and asbestos, the enforcement of their NESHAPS was credited
with having prevented 6000 and 7000 cancer deaths respectively. Vinyl
chloride produces a rare tumor in humans, angiosarcoma of the liver:
Asbestos, at low exposure levels, causes about equal numbers of
mesothelioma and excess lung cancer deaths. Angiosarcoma and
mesothelioma, a cancer of the pleural and/or peritoneal linings, are
very rarely seen tumors, and the number of cancers that the risk
assessments had estimated were prevented were far greater than the
historic background incidence of these tumors. Therefore these
estimates are not credible as being realistic risk estimates.
My second reason for believing that most risks are overstated was
my knowledge about the multiple margins of safety incorporated in the
risk assessment methodologies and the conservative nature of the
exposure assessment methods. These methods are not generally designed
to, and therefore cannot, generate accurate estimates of actual risks.
Rather, they are designed to generate possible regulatory levels that
are intended to have no significant risk.
______
[From the Risk Policy Report, September 22, 2000]
In the News--Air
scientists question sab's criticism of epa's residual risk program
Several members of an ad hoc Science Advisory Board (SAB) panel are
criticizing a commentary issued by the SAB's own executive committee
that questioned whether EPA was equipped to implement a major residual
risk analysis program that reburies EPA to assess 174 industrial source
categories.
The residual risk analysis program, mandated by section 112(f) of
the Clean Air Act, requires the agency to conduct assessments of 174
industrial source categories after their air toxics emissions sources
have been controlled by maximum achievable control technologies (MACT)
to determine if further controls are necessary. Under the CAA
amendments of 1990, residual risk assessments must be completed 8 years
after the MACT standards for each hazardous air pollutant (HAP) are
set.
Prompted by the ad hoc SAB panel's critical review of the agency's
approach to the residual risks posed by secondary lead smelters, the
executive committee July 25 urged EPA Administrator Carol Browner and
Congress to ``seriously re-consider the current Clean Air Act
Amendments mandates and their implementation strategy that depends on
scientific analyses that will be resource-demanding, at a minimum, and,
quite possibly, impossible to carry out in a credible manner.'' While
the committee endorsed the concept of science-based decision making at
the agency, it also recognized ``that no one is well served by asking
science to take on an impossible task.''
But several members of the ad hoc SAB lead smelters panel now say
the commentary goes too far. According to one panelist, ``we were
highly critical but took a constructive approach by emphasizing that
the agency needs to have a probabilistic approach to the data early
on.'' This source says it is ``quite possible for the agency to carry
out such analyses in a credible manner.'' Several members reportedly
have approached the ad hoc panel's chair, Phillip Hopke, with their
concerns about the executive committee's commentary. Another smelter
panel source emphasizes that the investment of more time and resources
in the program would be worthwhile in the residual risk program ``given
that you're dealing with a sophisticated industry with some past
history of litigation.'' The issue captured the attention of Senate
lawmakers who scheduled a hearing on the residual risk issue in late
July, but cancelled it because of scheduling conflicts.
EPA officials, meanwhile, have maintained that the agency has the
resources and technical skill to conduct the analysis and will work
with industry stakeholders to collect the data required to conduct
residual risk analyses and move forward with decisions (Risk Policy
Report, May 15, p.7; April 18, p33). One of the central reasons the
executive committee opted to write a commentary was that EPA has
substantial information on lead emissions unlike many of the other HAPs
that must still be reviewed. Residual risk analyses call for the
characterization of multiple HAPs, ecological risk analysis, population
risk estimates and careful assessment of uncertainty and variability
(Risk Policy Report, June 19, p. 15).
Accordingly to one EPA official ``in my view the commentary went
beyond what the SAB is charged to do which is to peer review science.
Should the board tell the agency when there is an adequate basis for a
decision that is the essence of making a policy call, and without
seeing the details of the original analysis, in my view they went over
the line.''
__________
Statement of Lee P. Hughes, Vice President, Corporate Environmental
Control, Bayer Corporation
i. introduction
Good morning Chairman Smith, Chairman Inhofe, Senator Baucus, and
members of the committee. My name is Lee Hughes and I am Vice President
of Corporate Environmental Control for Bayer Corporation. I have
responsibility for environmental matters for Bayer's United States
(U.S.) operations, including compliance with the Clean Air Act (Act).
I am here representing the American Chemistry Council (Council).
The Council represents the leading companies engaged in the business of
chemistry. Our members apply the science of chemistry to make
innovative products and services that make people's lives better,
healthier and safer. As we conduct our business, we are committed to:
improved environmental, health and safety performance
through Responsible Care,
common sense advocacy on major public policy issues, and
health and environmental research and product testing.
The business of chemistry is a $435 billion-a-year enterprise and a
key element of the Nation's economy. The chemistry industry is the
Nation's largest exporter, accounting for ten cents out of every dollar
in U.S. exports. This industry invests more in research and development
than any other business sector.
I commend Chairman Smith, Chairman Inhofe, and Senator Baucus for
holding this hearing on the important subject of residual risk under
the Act. The Council supported the 1990 Clean Air Act Amendments, and
for more than a decade has actively and collaboratively worked with the
Environmental Protection Agency (EPA) on its development of many air
toxics programs. We are proud of the tremendous progress we have made
reducing air toxics. For example, American Chemistry Council members
led all other U.S. businesses in cutting emissions of 30 key hazardous
air pollutants (HAPs) reported under the Toxics Release Inventory (TRI)
since 1990. While all U.S. manufacturing facilities reduced emissions
of these HAPs by 52 percent, Council members cut our emissions of these
substances by 64 percent.
Our industry supports the Clean Air Act's approach for regulating
air toxics, which first requires technology-based controls and then
looks at any remaining or ``residual'' risks. We believe the residual
risk effort can build on air toxics reductions to date and evolve into
a scientifically credible and effective regulatory program that
characterizes, prioritizes, and manages identified risks.
There are some early warning signs, however, that barriers exist to
achieving this goal. Your attention to this program, contemplated by
the Act, is an important step toward identifying, understanding, and
addressing these challenges. I would like to talk today both about the
progress we have made on air toxics as well as the issues we need to
address to ensure that the residual risk program gets off on the right
track.
ii. the chemical industry has significantly reduced air toxics under
the clean air act
The Act establishes a phased process for reducing air toxics
emissions from various industry sectors. Companies first implement
technology-based air toxics regulations, which are designed to
establish a common level of superior air pollution control across each
industry. This soon to be complete Maximum Achievable Control
Technology (MACT) program is expected to reduce annual HAP emissions
from stationary sources by over 1.5 million tons from 1990 levels.
The chemical industry was one of the first industries subject to
MACT regulations. The result has been dramatic air toxics reductions
from chemical sources according to EPA's own numbers. We are proud of
this achievement, as well as the many voluntary efforts our industry
has underway, such as Responsible Care(r), to continuously improve our
environmental and community performance. Responsible Care(r) represents
our commitment to respond to public concerns about the safe management
of chemicals and has rapidly become the single most important
performance improvement initiative within the chemical industry.
iii. key elements of a successful residual risk program
Eight or nine years after an industry's technology regulations are
promulgated, the Clean Air Act requires EPA to evaluate whether air
toxics risks from the regulated processes remain. If risks are
identified, EPA must promulgate new standards to provide an ``ample
margin of safety'' to protect public health and the environment from
those risks. EPA is now evaluating the chemical and other industries
subject to MACT standards to determine if their emissions pose
unacceptable remaining risks. If regulations are needed for the
chemical industry, they are due in 2003 under the Act's timeframe.
This means that many important decisions are being made now about
how the residual risk regulatory program will be designed and carried
out. The American Chemistry Council and its members are working
collaboratively with EPA on this effort. We believe that the residual
risk program must build on the emission reductions and successes of the
MACT program. In addition, our experience to date indicates that the
following key principles must be a part of the residual risk program to
ensure its success:
Prioritize real and scientifically validated risks.--We
support the use of prioritization techniques to rank remaining risks
posed by pollutants and sources within each evaluated industry
category. A prioritization approach to residual risk will screen out
negligible risks and focus regulatory efforts where risk reduction will
produce the greatest public health benefits. EPA already has taken this
approach in some of its work on the lead smelter industry, and we
support this effort.
Use the flexibility provided in the Act to reduce risks in
innovative and effective ways.--We support the risk management process
endorsed in the Act, which sets out key issues that must be considered
in designing this program. These include the scope of remaining risks,
the public health significance of HAP emissions, the cost of further
controls, and what risks are acceptable in the world in which we live.
The Act endorses a risk management process that considers an acceptable
level of risk based on health considerations, and then sets an ``ample
margin of safety'' based on cost, feasibility, and other factors. EPA
is not required to set a bright line that all sources must meet
regardless of other factors. This means the residual risk program can
be flexible, realistic, and encourage innovative approaches to risk
reduction.
Use high-quality data and peer-reviewed methods to
realistically assess risk and make regulatory decisions.-- We believe
EPA must use realistic exposure assumptions to accurately characterize
residual risks. This approach will place risks in context and avoid
overly conservative risk estimates. Also critical are validated risk
estimation methods and health benchmarks that fully account for all
currently available information. We believe a transparent and open
peer-review process also is an essential part of risk assessment. Where
there are gaps in our knowledge, we support Congress providing the
mechanisms, time, and research to fill these gaps.
iv. key limitations in present information, data, and methodologies to
assess residual risks within the statutory deadlines
To accomplish these important goals and design a successful and
realistic residual risk program, we must heed some early warning signs.
Our collaboration with EPA to date and other experiences, such as with
State air toxics programs, reveal some key limitations and shortcomings
in EPA's present information, data, and methodologies to assess
residual risks. EPA itself alludes to many of these troublesome areas
in its March 1999 Residual Risk Report to Congress. The Agency's
Science Advisory Board goes into more detail on present limitations in
its May 2000 Advisory on EPA's Draft Case Study Analysis of the
Residual Risk of Secondary Lead Smelters. We are concerned that,
without attention, these limitations will jeopardize the success of
this evolving regulatory program. Our concerns include the following:
Outdated health information.--The President's Commission
on Risk Assessment and Risk Management, created under the Act, has said
that ``data to assess the health risks of most hazardous air pollutants
for regulatory purposes are lacking'' and ``the status of exposure data
collection is no better.'' EPA's IRIS (Integrated Risk Information
System) data base, broadly perceived as the primary source of health
information on hundreds of chemicals, is critically out of date and
contains information of varying quality. IRIS' widely acknowledged
weaknesses are a true hindrance to the development of accurate risk
assessments.
The American Chemistry Council is dedicated to studying and
improving our collective knowledge of the health effects of chemicals.
Through our Long-Range Research Initiative, our members will spend more
than $100 million on health and environmental research related to
chemical use and exposure during the next 5 years. In addition, our
High Production Volume Chemical Testing program for screening and
testing thousands of chemicals, launched in 1998 as a partnership with
EPA and Environmental Defense, will require investments of at least
$500 million. These efforts and others, such as the current program at
the Chemical Industry Institute of Toxicology to develop a risk
assessment for formaldehyde using EPA's new cancer guidelines and the
latest science, are aimed at filling the IRIS gaps. Many of our
companies also have submitted or are preparing new IRIS assessments. We
strongly endorse EPA's recent efforts to open up the IRIS program to
such submissions, and encourage the Agency to further expand this
initiative.
However, these efforts alone are not enough. Staff and dollars for
IRIS must be increased. The process for updating IRIS also must be
expedited so new information on chemicals can be integrated or used in
regulatory decisions without requiring that the entire IRIS evaluation
process be repeated. IRIS is stuck in the last century, and we urge
that it be modernized and expanded before its limitations lead to more
erroneous risk assessments. Erroneous assessments may result in
unfounded public concern about air quality as well as waste limited
resources. Our experience shows that using the best science will
significantly reduce the uncertainty in making residual risk decisions
and assure that this evolving regulatory program addresses real risks
in the most effective manner.
Non-peer reviewed data, models and methods.--Good risk
assessments depend on high-quality science. We commend EPA for
presenting its preliminary secondary lead smelter case study to the
Science Advisory Board. This exercise, however, highlighted EPA's data
problems and showed that many of EPA's risk evaluation methods are not
peer-reviewed. We believe it is absolutely critical that EPA commit
that the data, models, and methods used for regulatory decisionmaking
will be consistently and comprehensively subjected to a transparent
scientific review process. This process must be balanced and engage
academics, industry, states, scientists, and non-governmental
organizations in an open process. Adequate time, funding and resources
for followup to recommendations is also important so scientific input
can be fully incorporated and addressed.
Incomplete emissions data and site characterization
information.--Good risk assessments depend on a highly credible source
of post-MACT emissions data for the many sources to be evaluated. Good
risk assessments also depend on accurate information about facility
locations, distance to neighbors, stack heights, and other important
details. EPA's most recent emissions data set is from 1996, which for
our industry represents pre-MACT emissions levels. Since this data was
not collected for risk assessment purposes it also contains other
significant limitations. Our industry is voluntarily providing EPA with
better information about the chemical sources now under review, but the
task is immense. More effort is needed by all parties in this area to
do a better job collecting, categorizing, and assessing such data.
Flawed fugitive emissions estimation methods.--Good risk
assessments also depend on accurate estimates of ``fugitive
emissions''--low-level emissions from, for example, piping connections
or valves. More simplistic methods currently in use were not intended
for risk assessment purposes and tend to grossly overestimate fugitive
emissions. Companies have developed new and more accurate ways to
estimate these emissions. To reduce uncertainty in risk assessment,
these improved methods need acceptance and use by EPA and other
regulatory agencies.
Statutory time constraints.--We are concerned that these
significant limitations can not be addressed under the present
statutory time clock. As noted by the Science Advisory Board, EPA must
conduct over 170 residual risk assessments and these ``data gaps are
likely to be even more of a problem'' in future assessments. To add to
the challenges, the Act requires compliance with new residual risk
standards within 90 days of promulgation-a near impossibility for most
sources. Despite our best efforts, it will not be long before a
residual risk standard deadline is missed. Unless action is taken now,
this program may end up operating under court ordered deadlines and in
settlement discussions, hindering our ability to make good decisions
founded on science.
iv. conclusion
We are convinced that there is a better way for this program to be
carried out, provided we heed these warning signs and keep the key
elements for a successful program outlined here in the forefront of our
minds. Our industry is committed to working with you, EPA, and other
stakeholders to ensure that this regulatory program gets off to a solid
start.
In closing, we must strive to prioritize risk reduction efforts and
maximize the effectiveness and resources of all stakeholders to achieve
cleaner air. To accomplish these goals and design an effective residual
risk program, we need to base regulatory action on prioritized
environmental challenges, use peer-reviewed and state-of-the-art
scientific methods, and generate accurate health and emissions data. I
reiterate our commitment to work with you and all stakeholders to
achieve these goals.
Chairman Smith and members of the committee, thank you for hearing
my testimony today. I appreciate the opportunity to provide you with
our views on this important topic. I would be happy to answer any
questions you may have.
______
Responses by Lee P. Hughes to Additional Questions from Senator Smith
Question 1.--In the likely event that the IRIS values are not
updated in time for residual risk standards, do you believe there
should be a process for EPA to consider new toxicity information during
the residual risk rulemaking process? Isn't this critical to ensuring
that the standards are based on the best science possible?
Response. We agree it is unlikely that IRIS values will be updated
in time to be used in the residual risk assessments,\1\ and for that
reason, it is critical that EPA develop an efficient, expeditious
process to incorporate the latest and best science into residual risk
assessments and the risk management decisions that follow. Due to the
significant Maximum Achievable Control Technology (MACT) reductions, it
will be important to correctly identify and characterize remaining
risks. Application of an out-of-date IRIS value could create the
appearance of risks when none exist or underestimate risks that need
attention. We are committed to working with you and the Agency to
develop an appropriate process that enables EPA to consider new
toxicity information during the residual risk assessment and rulemaking
process.
---------------------------------------------------------------------------
\1\ Since 1995 EPA has added only four chemicals to the IRIS data
base and revised the files for only 16 others. For more details on
IRIS' limitations, see Science Advisory Board Environmental Health
Committee, Review of the Draft Report to Congress Characterization of
Data Uncertainty and Variability in IRIS Assessments, Pre-Pilot vs.
Post-Pilot (Sept. 26, 2000) 7; EPA Screening Evaluation Report:
Presentation and Discussion of Uncertainty and Variability in IRIS
Assessments (July 2000), Table 3; ICF Consulting, Screening-Level
Assessment of the Need to Update EPA's IRIS Data base (March 17, 2000),
Exhibit 2.
Question 2. In your testimony you stressed the importance of
updating the IRIS data base at EPA that contains the health benchmarks
or values EPA will use in the risk estimation process. Specifically,
you stated that the process for updating IRIS must be ``opened up.''
What do you mean by this statement and do you have any specific
recommendations?
Response. EPA recently acknowledged that IRIS is a public resource
and that its maintenance and upgrading are not merely matters of EPA
internal management prerogative.\2\ When we referred to ``opening up''
the IRIS updating process, we were referring to recent positive steps
EPA has taken to involve non-EPA parties in the management and
operation of IRIS, including:
---------------------------------------------------------------------------
\2\ See EPA FY2000 Annual Performance Plan and Congressional
Justification, at VII-37 (``[IRIS] is widely used for risk assessments
and other health evaluations at all levels of government, as well as in
the private and public sectors. . . . Risk assessors everywhere look to
EPA to provide it.'')
---------------------------------------------------------------------------
More active solicitation of available information about
chemicals that EPA is reviewing;
Allowing outside groups on a limited basis to produce
drafts of the toxicological review that will speed the process and can
constitute the underlying data for the Agency's conclusions regarding
benchmarks; and
External peer review of the IRIS decisions, with the
opportunity for the public to provide comments to EPA.
We also recommend that EPA take the following additional steps to
further ``open up'' the IRIS process:
Conduct the IRIS needs assessment requested by the Senate
Appropriations Committee's fiscal year 2001 report.--Congress needs to
know the real scope of the IRIS backlog and what priority chemicals are
not currently part of IRIS. The assessment should include
recommendations from State environmental officials, industry, public
interest groups, and the general public. The assessment should address
the budget needed to bring the IRIS program up to a high level of
quality in an acceptable number of years.
Encourage outside scientists familiar with current
literature on specific chemicals to provide draft toxicological reviews
for EPA consideration.--This maintains EPA's independence and
capitalizes on the private sector's and other government agencies'
abilities to perform some of the basic literature reviews that
contractors now do for EPA. This approach is being successfully
employed in the European Union, where industry groups provide many of
the draft science documents and risk assessments that are the starting
point for government consideration. European regulatory and science
review groups use these evaluations to develop potency factors and make
health-based regulatory decisions.
Allow other stakeholders to nominate chemicals for
priority updating.--This will ensure that the most urgently needed
updates are identified and carried out in time to affect future
regulatory decisions.
Develop interim procedures to account for IRIS
limitations.--For example, EPA could conduct less resource-intensive
``partial'' IRIS updates where there are important new studies on a
chemical, rather than a comprehensive entire file review. Or, new
studies could be listed in IRIS with a disclaimer informing users that
the health information does not include a consideration of these latest
studies.
Question 3.--Comparative risk assessment is a tool used to
characterize and rank environmental problems. Do you believe that EPA
uses enough benefit-cost analyses (BCA) in characterizing the
effectiveness of environmental solutions? Is EPA's use of BCA
appropriate?
Response. We believe that EPA should use BCA more often when
characterizing and ranking environmental problems, particularly today
when many of the easy solutions to reducing pollution have been found
and accomplished. Under the decisionmaking process for residual risk
required by the Clean Air Act, however, EPA is required to consider
cost, feasibility, and other factors when setting the required ``ample
margin of safety''. See Sec. 112(f)(2)(B) (reference to benzene
rulemaking, 54 Fed. Reg. 38,044). Thus, for residual risk the use of
BCA is not only appropriate, it is required.
______
Responses by Lee P. Hughes to Additional Questions from Senator Baucus
Question 1a. You've noted some gaps that you believe need to be
filled to adequately characterize residual risk. I assume you mean that
must happen before regulations can be issued. Is that correct?
Response. We do not believe that all residual risk regulations
should be delayed until all data gaps are filled. Our testimony touched
on two key gaps--a lack of post-Maximum Achievable Control Technology
(MACT) emissions information and outdated health effects information on
hazardous air pollutants (HAPs). In many cases, there is adequate
emissions information for the sources at issue, and health effects
information on the relevant HAPs for EPA to make sound regulatory
decisions.
However, for some HAPs and some source categories, we will need
more current and better information to produce sound, scientifically
based decisions. We are committed to working with EPA to identify which
HAPs need priority attention and to determine what steps need to be
taken to allow EPA to make solid decisions. We also will continue our
work to voluntarily provide EPA with current, post-MACT emissions
information (see response to Question 2, below). EPA still may find
that additional data gathering in this area is needed to complete
regulatory decisions. These are the gaps that we believe may affect
EPA's ability to issue some residual risk rules within the statutory
deadlines.
Question 1b. How long would it take to fill those gaps if more
resources aren't given to EPA to do the work?
Response. There is no doubt that the ``gap filling'' workload is
heavy and that EPA needs adequate resources to fill key data gaps in
emissions information and health effects information. While we cannot
predict how long this effort might take, we do have the following
suggestions for managing the workload:
Determine whether EPA has adequate resources to fill these
gaps and whether the Agency is properly allocating these resources. We
are concerned that there has not been a meaningful increase in the
funding EPA has allocated to ``air toxics research'' or ``air toxics
standards'' in the fiscal year 2000 or fiscal year 2001 budgets;
Identify and prioritize which HAPs are most critical to
the residual risk rulemaking effort and need timely and complete
evaluation;
Determine where better post-MACT emissions information is
needed and how we can collectively do a better job gathering this
information in the future; and
Assess how gaps may be filled through the non-EPA and
private sector efforts underway to improve our collective knowledge of
the health effects and emissions of pollutants.
Question 1c. Do you think the regulated industries would be willing
to pitch in and provide additional resources beyond those you mentioned
in your testimony?
Response. While we cannot speak for other industries, the chemical
industry is already making a serious contribution to chemical research
and testing. We are proud of our efforts and believe they will
contribute to our overall knowledge. As our work progresses, we will
assess how we can make additional contributions. Some of our present
research activities are described below:
Through the American Chemistry Council's Long-Range
Research Initiative, our members will spend more than $100 million on
health and environmental research related to chemical use and exposure
during the next 5 years.
Our High Production Volume Chemical Testing program for
screening and testing thousands of chemicals, launched in 1998 as a
partnership with EPA and Environmental Defense, will require
investments of at least $500 million.
Many of our companies have submitted or are preparing new
IRIS assessments, which will help fill additional gaps.
We are working with EPA on a major program to address
children's health issues.
See response to Question 2, below, regarding specific
input on post-MACT emissions information for the residual risk program.
Question 1d. Would a per pound tax on HAPs emissions be an
efficient way to obtain such resources?
Response. An emissions tax would be a highly inefficient means of
promoting accurate risk assessments and risk management decisions for
residual risk. Segregation of funds from a dedicated revenue source
would create additional resource management problems for EPA.
Additionally, in the past two budget proposals EPA sought to allocate
significant funds to non-statutory areas (e.g., Clean Air Partnership
Fund), rather than to congressionally-mandated programs like residual
risk. In fact, there has been no meaningful budget increase for ``air
toxics standards'' or ``air toxics research'' in 2 years. Congress
should evaluate whether present resources are appropriately applied.
A tax also is inconsistent with the Act's structure for managing
HAPs from major stationary sources. Industries assessed for residual
risk already have installed MACT at a significant cost to many
companies. A tax on HAPs would punish these sources for good faith
compliance with the law.
Question 2. Has EPA enabled your industry to provide input on the
residual risk program and on the specific risk assessment for your
industry?
Response. We have had a good working relationship with EPA
concerning the overall conceptual framework for the residual risk
program over the past several years. We have taken advantage of formal
opportunities to provide input to the Agency, such as our commenting on
the Report to Congress on Residual Risk and the Secondary Lead Smelter
Case Study. In addition, EPA has been willing to meet with us and to
share ideas at appropriate times.
This year EPA moved into the risk assessment phase for the sector
of our industry subject to one of the first residual risk evaluations
(facilities subject to the 1994 Hazardous Organic NESHAP (HON)). We
have provided EPA with information about HON facilities, their
locations, and emissions. Just last week we contacted over 60 companies
requesting their voluntary assistance to provide site-specific
emissions information to EPA to improve the residual risk assessment.
Question 3. What improvements could be made to the relationship to
ensure an open and collaborative sharing of data?
Response. We will need to work collaboratively with EPA and other
stakeholders in the coming months on issues relating to regulatory
structure, risk communication, and risk management. One improvement to
the relationship could involve open recognition by all parties of the
tight: statutory deadlines. Our experience shows that in the face of
fast approaching deadlines EPA often reduces stakeholder dialog and
input, as stakeholder meetings are viewed as an impediment to achieving
deadlines rather than a means to improve the regulatory process. We
expect that part of the necessary open and collaborative process will
be an honest assessment of what can be accomplished under the Act's
deadlines.
__________
Statement of Robert Brenner, Deputy Assistant Administrator, Office of
Air and Radiation, U.S. Environmental Protection Agency
Mr. Chairman and members of the committee, I welcome the
opportunity today to testify on EPA's plans for implementing the
residual risk program, which is one component of a broader strategy
mandated in the Clean Air Act Amendments of 1990 to protect public
health and the environment against toxic air pollution.
The 1990 Amendments called for a two-phased approach to reducing
toxic air emissions from major industrial sources. First, EPA is to
issue industry-by-industry standards to ensure that all sources are
appropriately controlled. Second, in the residual risk phase, EPA is to
assess the remaining risks from those industries and, if necessary,
require reductions in toxic air emissions to protect health and the
environment.
Congress reached a bipartisan compromise on the residual risk
provisions in 1990 after years of dialog and debate over the best way
to achieve effective and reasonable air toxics control. A decade later,
EPA continues to believe that it makes sense to evaluate whether
Maximum Achievable Control Technology (MACT) standards provide the
public with adequate health and environmental protection, and to take
action if they do not. Although the job will not be easy, EPA with the
aid of the scientific community (including the National Academy of
Sciences) has developed risk assessment methodologies and risk
management procedures that allow for making reasoned decisions on
whether to require further emissions reductions, based on the available
scientific information and consideration of uncertainties.
Today, I will describe the general approach to risk assessment and
risk management that EPA will use in deciding whether further
reductions in toxic air emissions are needed from industrial facilities
that have met technology-based emission limits. To set the stage, it is
useful to put the program in context by providing some historical
background and outlining EPA's overall air toxics strategy.
air toxics and the 1990 clean air act amendments
At the time Congress amended the Clean Air Act (CAA) provisions on
hazardous air pollution in 1990, it was well established that the
public is exposed to air toxics such as lead, benzene, dioxin, mercury,
chromium, and other compounds. It was also known that toxics found in
the air can cause cancer or other serious health effects such as
neurological damage, miscarriages, birth defects, or lung damage.
Industry reports required by the Emergency Planning and Community
Right-to-Know Act of 1986 revealed that manufacturing industries alone
had emitted more than 2.7 billion pounds of toxic chemicals into the
air in 1987. Risk assessments indicated that individuals living near
some industrial facilities faced potentially high cancer risks. Studies
found that millions of people in American cities faced some elevated
risks from a complex mixture of toxic chemicals emitted by multiple
sources ranging in size from big petrochemical plants to dry cleaners
to motor vehicles. And atmospheric deposition of hazardous air
pollutants was identified as contributing to toxic pollution in the
Great Lakes. Neighboring states and Canada had issued health advisories
against eating certain varieties of fish caught in the Great Lakes
because they contained elevated levels of PCBs, mercury and other
toxics.
All this was highlighted in congressional hearings. During the 1990
revision of the Act, Congress concluded that the pre-1990 hazardous air
pollutant provisions had provided fertile ground for 20 years of
emotional and often endless debate and litigation. Those provisions
called for EPA to list and regulate hazardous pollutants one at a time
based on the risks they posed. The result was gridlock. In 20 years,
EPA listed only eight pollutants and regulated only seven. The
regulations covered only some of the sources emitting those pollutants.
In response, Congress overhauled the Clean Air Act to ensure
effective actions to protect public health from nearly 190 toxic air
pollutants. The Act mandates a two-phased approach: cut toxic emissions
substantially by requiring maximum achievable controls considering
costs on major sources, and use targeted approaches to reduce
particular types of risks.
In the first phase, EPA is directed to issue technology-based
emissions standards on an industry-by-industry basis to bring down the
amount of toxics in the air and reduce exposure to air toxics among
citizens living nearby. This approach--requiring dirtier facilities to
achieve the level of performance already being achieved by cleaner
facilities of the same type--has proven very successful. MACT standards
issued to date will reduce annual emissions of air toxics by 1.5
million tons--many times the reductions achieved by standards issued
during the 1970-90 period. To provide industry with greater flexibility
on ways to comply with MACT standards, we develop numerical emissions
performance standards whenever feasible, and typically include other
features such as alternative compliance options or emissions averaging.
As we work to complete the MACT standards, we are implementing the
second phase of the toxics program targeted to particular types of
risks. Key components of this second phase include:
assessing residual risks of toxic air emissions from MACT-
regulated sources to determine whether further controls are needed to
protect public health and the environment.
implementing the Integrated Urban Air Toxics Strategy,
which is aimed at reducing risks in urban areas from 33 priority
pollutants emitted by small ``area'' sources, motor vehicles and other
sources.
continuing assessments of atmospheric deposition of air
toxics into the Great Lakes, and considering additional actions that
may be needed to reduce emissions of those toxics.
conducting National Air Toxics Assessment activities to
provide citizens, localities, states and ourselves with better
information on toxic emissions, exposure and risk.
the residual risk program
In crafting the 1990 Amendments, Congress recognized that in the
case of some industries, emissions reductions achieved by the MACT
program might not be sufficient to protect public health and the
environment. So the 1990 Amendments direct EPA to evaluate the
remaining risks from each regulated source category. If necessary to
protect public health or the environment, EPA is to issue residual risk
standards requiring further emissions reductions. Any such standards
are to be issued within 8 years of the date the MACT standard was
issued (nine years for certain early standards).
The details of these provisions represent a hard-won compromise
achieved by the 102d Congress, which spent as much time developing the
residual risk provisions as it did on any portion of the 1990
Amendments. The provisions reflect attention to a variety of
conflicting concerns--the concerns of people exposed regularly to air
toxics in the air that they breathe, the economic concerns of
industrial facilities, and concerns about the uncertainty, imprecision
and complexity associated with risk assessments of toxic air
pollutants.
Those concerned about elevated risks from air toxics include
minority and low-income residents who often are disproportionately
represented in neighborhoods near industrial sites. In evaluating
residual risks, EPA will look closely at potential exposures in nearby
neighborhoods and be cognizant of subpopulations such as children and
pregnant women who may be especially vulnerable to some toxic
pollutants.
For many source categories, this program will be challenging to
implement because of data gaps and uncertainties involved with risk
assessments for hazardous air pollutants, and differing views among
stakeholders over how risk assessors and risk managers should account
for uncertainties. These issues are not new. Under the old pollutant-
by-pollutant regulatory system in the 1970 Clean Air Act, these issues
severely hindered implementation of the Federal air toxics program.
While there have been great strides made in the field of risk
assessment since the 1990 Amendments, risk assessment by definition
will always entail uncertainties.
Knowing this, Congress designed the residual risk provisions of
the1990 Amendments to provide for decisionmaking in the face of
uncertainties. To lay the groundwork for the residual risk program,
Congress required three reports--two by independent panels of
scientists, and one by EPA--to address issues concerning risk
assessments and risk management. Congress also provided a detailed
framework to guide EPA's residual risk decisions in a world in which we
don't have all the information we would like.
Today, all three statutorily required reports on risk assessment
and risk management are complete. A 1994 report by the National
Research Council (NRC) of the National Academy of Sciences, mandated by
section 112(o) of the CAA, reviewed EPA's risk assessment methods. A
1997 report by the congressionally mandated Commission on Risk
Assessment and Risk Management (CRARM), mandated by section 303 of the
1990 Amendments, examined risk assessment and risk management issues
relevant to hazardous substances under various Federal laws. After
evaluating these reports, EPA in 1999 provided a major Report to
Congress describing how the Agency will implement the residual risk
program, using the available scientific information and methods.
EPA's implementation approach for the program reflects the
suggestions of the scientific committees. For example, the NRC report
noted that neither the resources nor the scientific data exist to
perform a full-scale risk assessment on all the chemicals listed as
hazardous air pollutants (HAPs) and their sources. Therefore, the NRC
supported an iterative approach to risk assessment of source categories
emitting HAPs. This approach would start with relatively inexpensive
screening techniques used to determine whether the evaluated source
category is below the statutory level of concern, or whether we need to
conduct a more refined analysis before we can make a determination. (We
will not regulate based on the results of a screen.) As a particular
situation warranted, we would move to a more resource-intensive level
of data-gathering, model construction and model application to produce
a risk assessment providing greater certainty. The result would be a
process that supports the risk management decisions required by the CAA
and provides incentives for better data and further research, without
the need for costly case-by-case evaluations of individual chemicals of
every facility in every source category. The CRARM agreed that the EPA
should use an iterative approach when conducting risk assessments and
elaborated on the general approach presented by the NRC. The Agency is
using an approach that is consistent with that presented by the CRARM
to undertake its residual risk assessments.
After a residual risk assessment is conducted, EPA must determine
whether a residual risk standard should be established to achieve
further emissions reductions. Specifically, EPA is to issue a residual
risk standard for a source category if required ``to provide an ample
margin of safety to protect the public health, or to prevent, taking
into consideration costs, energy, safety and other relevant factors, an
adverse environmental effect.'' Congress provided specific guidance on
how this residual risk decision is to be made for hazardous air
pollutants that lack a health effects threshold (e.g., many
carcinogens) by endorsing the framework EPA developed for the 1989
benzene national emissions standard. This framework--developed through
notice and comment rulemaking in response to a 1987 decision by the
Court of Appeals for the District of Columbia Circuit--calls for a two-
step decisionmaking process considering multiple factors.
In the first step, EPA determines a ``safe'' or ``acceptable'' risk
level that considers all health information--including the risk level
of highly exposed individuals, the number of people exposed within each
lifetime risk range, the overall incidence of health effects, the
science policy assumptions associated with the risk measures, and the
weight of evidence that a pollutant is harmful to health. EPA
ordinarily will presume that a 1 in 10,000 lifetime risk of cancer to
the individuals exposed to the maximum level of a pollutant represents
the upper end of the range of acceptable risk. However, this is not a
rigid line; rather it is a presumption to be weighed with the other
factors.
In the second step, EPA determines the level of the enforceable
emissions standard needed to provide an ``ample margin of safety.'' In
choosing this level, EPA considers again all health information--
including the number of persons at risk levels higher than
approximately 1 in 1 million, the nature of the assumptions underlying
the risk assessment, and weight of evidence that a pollutant is
harmful. In determining the margin of safety, EPA also considers costs
and economic impacts of controls, technological feasibility and other
relevant factors.
This congressionally-endorsed approach is consistent with risk
management approaches of other EPA programs intended to broadly protect
public health. For example, other EPA programs use a risk management
range of 10-6 to 10-4 under their reasonable maximum exposure scenario
to guide their decisionmaking for carcinogens.
Also, the methods used to generate risk estimates for the residual
risk program are consistent with those of other EPA programs. To
address uncertainties, EPA makes scientifically sound judgments and
assumptions about hazard and exposure to generate ``reasonably
conservative'' risk estimates. By ``conservative'' we mean that true
risks may be higher, but are likely to be lower. There are parameters
that can substantially increase or decrease the estimated risk; EPA
does not use conservative assumptions for all of these. For example,
where we lack adequate information to support a quantitative assessment
for a pollutant, we implicitly assume that the risks from that
pollutant are zero. The result, in the end, is that our risk estimates
are plausible and do not represent worst case estimates.
This committee has expressed interest in the findings of an EPA
Science Advisory Board (SAB) panel that recently reviewed a case study
illustrating the approach EPA plans to use to conduct risk assessments
for the residual risk program. The SAB subcommittee said that EPA
methodology ``is consistent with the methodology described in the
Report to Congress,'' (which the Science Advisory Board reviewed and
supported in 1998), and that ``the assumptions used are consistent with
current methods and practice.'' The subcommittee also made valuable
substantive comments and suggestions for improvements, which EPA is
incorporating. While the SAB did not find any ``showstoppers'' (their
word) with the approach used, they did identify several issues that
should be addressed such as a more fully evaluated model to predict
exposure to toxics through multiple media, and improved data collection
efforts. The SAB expressed particular concern about the availability of
sufficiently precise scientific information that would support residual
risk analysis. EPA is incorporating the Science Advisory Board's
suggestions into our residual risk assessments. We are providing the
committee with a copy of our formal response to the SAB. As we stated
to the SAB, EPA will obtain peer review on the full case study risk
assessment when it is completed.
As mentioned earlier, we are working to improve our data on air
toxics (through our NATA or National Air Toxics Assessment activities)
and our risk assessment methods. For example, we are improving the
National Toxics Inventory, which is a repository of source specific air
toxics emissions data from states; working with states and cities to
expand monitoring of ambient air toxics levels (a plan which received a
positive review from the SAB); and developing a new, better, multi-
pathway methodology in TRIM (Total Risk Integrated Methodology), which
has received two very favorable reviews from the SAB. We are also
conducting national- and local-scale air quality, multimedia and
exposure modeling to help characterize risks associated with air toxics
exposures. Furthermore, we have been working with our colleagues in the
Office of Research and Development for nearly 2 years to develop the
Agency's Air Toxics Research Strategy. This strategy helps us to
prioritize our research efforts on health and environmental effects and
exposures to ambient and indoor sources of air toxics. Over time, these
activities will help us set program priorities, provide the public with
risk information, and track progress toward meeting national air toxics
program goals.
In light of current uncertainties, some may suggest that EPA wait
for more complete information before attempting to assess and address
any risks from air toxics remaining after MACT. The flaw in this
approach is that, in some cases, individuals may continue to be exposed
to unsafe levels of toxics around these facilities while we fail to act
based on information that is available now. For other source
categories, available information may reassure concerned citizens that
the facilities near them are well controlled. In the field of
environmental protection, as in much of life, there are few decisions
for which we would not like to have more information. The reality is
that to avoid paralysis, we must make reasoned choices based on the
information we have.
Looking ahead, EPA has no preconceived notions of what residual
risk analyses will show. Our plan is to use the available information
to assess residual risks from each source category. We will use the
most up-to-date credible and relevant information on chemical hazards.
Taking into account uncertainties and the assumptions in the risk
analysis, we will make a reasoned judgment as to whether the weight of
the evidence supports requiring further emissions reductions to protect
public health and the environment. If there is not sufficient evidence
of a threat, EPA will not issue a residual risk standard. If toxic
emissions are unsafe based on the framework provided by Congress, EPA
will take protective action.
Mr. Chairman, thank you for the opportunity to testify. I would be
pleased to answer any questions that you may have.
__________
Statement of Dr. Philip Hopke, Chair, Residual Risk Subcommittee,
U.S. Environmental Protection Agency Science Advisory Board
Mr. Chairman and members of the committee, my name is Dr. Philip
Hopke. I am testifying today as an individual, and I am honored to be
here to discuss with you my views of the Residual Risk Subcommittee's
(RRS) report on the residual risk methodology as described in EPA's
Report to Congress (USEPA, 1999), as applied to the secondary lead
smelter source category (USEPA, 2000). I chaired the RRS which is a
subcommittee of the U.S. Environmental Protection Agency's Science
Advisory Board's (SAB) Executive Committee. SAB is an independent FACA
committee established by Congress. My testimony will reflect the
consensus views of myself and the other members of the RRS, with added
input and endorsement of the report from the SAB's Executive Committee.
On March 1-2, 2000, the Residual Risk Subcommittee conducted a peer
review of an Agency draft case study of the residual risk assessment
methodology for the secondary lead smelter source category (USEPA,
2000). The SAB understands that the Agency plans another iteration,
including additional data collection and analysis before the results
are considered for use in a regulatory context. The review of the
seven-volume set of material focused on eight specific questions that
are addressed in detail in the accompanying SAB report.
In short, the Subcommittee concludes that the Agency developed a
useful, self-described ``work-in progress.'' The methodology used in
this interim work product, as far as it currently goes, is consistent
with the methodology described in the Report to Congress. Further, many
of the assumptions used are consistent with current methods and
practice. The case study provides an example of how the approach
presented in the Report might be implemented. However, it also raises a
number of concerns that we have provided in our report on this document
(EPA-SAB-EC-ADV-00-005 ``An SAB Advisory on the USEPA's Draft Case
Study Analysis of the Residual Risk of Secondary Lead Smelters''). The
major concerns will be highlighted here.
Because the Subcommittee has not yet seen a full residual risk
analysis and, thus, is unable to comment on the complete process, a
number of important concerns were identified that should be addressed.
Specifically, this interim analysis does not include the following
important elements:
(1) an ecosystem risk assessment
(2) a health risk assessment that includes population risks
(3) a full analysis of uncertainty and variability
(4) a computer model for assessing multimedia transport and fate
that has been adequately evaluated
(5) a clear description of the process and how the assessments will
be linked to the eventual risk management decisions.
With respect to the specific approaches taken in the interim
analysis, a number of questions are discussed in detail in the
Subcommittee's report.
ecosystem risk assessment
One of the greatest shortcomings of the case study in its
incomplete State is that only the first stage screening analysis has
been done for the ecological risk assessment. Even in this screening
the top carnivore species were not included. This is the group of
organisms at greatest risk from persistent and accumulated toxic
chemicals. While the Office of Air Quality Planning and Standards
(OAQPS) acknowledges that a full ecological risk assessment is needed,
the Subcommittee is disappointed at the pace at which the assessment is
being developed and implemented for ecology and natural resources. It
would appear that a more concerted and scientifically complete analysis
will be needed in order to meet the mandate of the Clean Air Act
Amendments (CAAA) with respect to ecological risk.
health risk assessment that includes population risks
Regarding the health risk assessment portion of the case study, the
Subcommittee finds that, within the limitations of data and resources,
the approaches employed by the Agency were able to qualitatively
identify potentially high human health risk situations. However, the
Subcommittee also concluded that the currently available science
presented in the working document is insufficient to be comfortable
with the quantitative values estimated by the models currently used. In
particular, the analysis calls into question the ability of the model
to reliably quantify the amount of the deposited contaminant
transferred in the food chain. In addition, the current risk assessment
will have to be further developed in order to include population risks
if it is to meet the needs of the Agency.
computer model for assessing multimedia transport and fate that has
been adequately evaluated
The case of multimedia computer models is one of the other major
areas with which the Subcommittee has concerns. It seems that the
models were applied without due consideration of the plausibility of
the assumptions and the physical meaning of the results. In several
cases, results presented in the draft report were implausible in that
the predicted concentrations would have produced immediately observable
results on the affected human and ecological populations. For example,
ambient lead concentrations measured because of the National Ambient
Air Quality Standard for Particulate Lead could be used to test the
concentrations at site boundaries of these facilities. Thus, it
suggests that overly conservative estimates were likely to have been
used. Such results could be eliminated if an iterative process were
used in which implausible results are flagged so that the Agency can
make appropriate revisions in the model and/or its inputs, and the
model run again. A number of plausibility checks were described by the
Subcommittee, and in public comments, that would provide checkpoints in
the analysis and, thereby, indicate the need for alternative
assumptions and recalculation. Inclusion of these checkpoints would be
helpful to both the Agency and the reader.
In addition the models being used need to undergo rigorous peer
review. In this test case, a model, IEM-2M, originally used for mercury
movement in the environment was modified for lead. However, this model
was never rigorously reviewed even for its utility in the mercury
modeling. The Agency has been developing a new multimedia exposure
model, Total Risk Integrated Methodology (TRIM), that has undergone an
initial review by the SAB that was encouraging. However, it appears now
that the completion of this model and its use in risk assessment has
been slowed so that it may not be available in the near term. This
delay produces serious doubts in any of the assessments that have to be
based on a temporary model that has not been subjected to careful
external scrutiny.
full analysis of uncertainty and variability
The lack of a more rigorous treatment of uncertainty and
variability may lend an aura of precision to the risk estimates in the
case study that is not warranted and could, thereby, be misleading for
Agency decisionmakers. In particular, the uncertainty analysis omits
some important aspects of uncertainty and does not clearly distinguish
between uncertainty and variability.
clear description of the process and how the assessments will be linked
to the eventual risk management decisions
Moving beyond the strictly technical aspects of the document on
which the SAB has been asked to provide advice, I would like to share
with you my comments on what the subcommittee understood to be the
Agency's intention to make decisions based on these results.
Specifically, the Agency is mandated under Section 112(f) of the Clean
Air Act to conduct the residual risk assessment and to make a decision
about whether or not further regulation is necessary in order to
protect public health and the environment. In particular, as stated in
the Agency's response to the previous SAB review of the Report To
Congress (SAB-EC-98-013), ``the decision made with the results of the
screening analysis is [either] no further action or refine the
analysis, while the decision made with the results of the more refined
analysis is [either] no further action or consider additional emissions
control.''
As discussed above, as currently presented, the results of the
refined analysis will provide essentially the same answer as the
initial screening analysis; that is, an even more refined analysis is
needed. Therefore, the case study has not achieved its decision
objective, and another level of analysis or iteration is needed. A
better-informed decision will be possible if the results of the case
study more fully reflect both the best estimate of the risk combined
with an adequate uncertainty/variability analysis that will more
clearly define the range of risks.
An important policy question arises as to how good do such residual
risk assessments need to be. The understanding the RRS came to during
its discussion is that when the form of controls specified in Title III
was being considered by Congress a decade ago, the expectation for the
level of these residual risk analyses was quite low. The scientific
basis of risk assessment has grown considerably over the past 10 years
and thus, the level of expectation from the scientific community such
as those who have served on the SAB Subcommittee has risen
considerably. Thus, the Subcommittee has expressed its concerns
regarding future assessments.
The present source class, secondary lead smelters, is a relatively
data-rich category. Because of the existence of the lead National
Ambient Air Quality Standard (NAAQS) and the concern for blood lead
levels in children, there are more data in the vicinity of these source
types than are likely to be available for other HAPs from other source
types. The basic Congressional approach of imposing controls and
assessing residual risk is a sensible response to the problem of HAPs
emissions. However, the number of HAPs and the number of source types,
coupled with the limited data on speciated emissions and quantitative
dose-response information, makes the residual risk task into a
substantial one.
At this time, it appears that there have not been sufficient
resources provided to EPA to allow their Office of Air Quality Planning
and Standards (OAQPS) to collect and assess all of the pertinent data
from EPA, state/local air quality, and public health agencies that
could be fruitfully brought to bear on this problem. For example, the
Subcommittee was told that it had not been possible to get the lead
NAAQS monitoring data from AIRS to provide checks on the fugitive
emissions estimates because of resource limitations.
There are certainly not sufficient resources to permit the testing
of specific HAPs for their toxicity if those dose-response data are not
already available. Such testing would be expensive and may not be the
best use of limited resources. In the case of secondary lead smelters,
only seven of the 50 identified HAPs were excluded from the residual
risk assessment due to the lack of dose-response data. This lack of
data will likely pose much greater problems when other source
categories are addressed in the future. Such data gaps could lead to
the omission of compounds from the assessment, resulting in a
subsequent underprediction of the residual risk. It may be possible to
utilize computational chemical methods to provide at least an
estimation of the possible risk. However, that would require some
limited additional effort.
Accordingly, I wish to use this opportunity to express the RRS's
concern regarding the level of analysis that can and should be done to
assess the residual risk as part of the control of hazardous air
pollutant emissions. The RRS believes it is possible to provide more
quantitative and useful human health and ecological risk assessments
than is currently envisioned for a reasonable investment of additional
resources for data collection and some additional outside expertise as
appropriate. The resulting assessments will be much more credible.
As we all know well, science alone does not a decisionmake. Science
can inform but policy decides when making regulatory judgments. I say
this, because many non-scientific considerations are taken into account
when making decisions (e.g. legal precedent, policies, values,
economics, technical feasibility, etc.). Each must be considered
carefully and applied wisely if the decisions are to be effective and
widely accepted by the public. However, while the decision inputs based
on values, politics and other social considerations are often
debatable, we expect the science to be based on facts determined by
measurable, repeatable observations of nature. More explicit
recognition of this problem by members of Congress could help the
Agency carry out its duties more effectively and could help provide the
public with a clear understanding of how Congress interprets National
priorities.
I want to express my gratitude to the members of the Committee for
inviting me and giving me the opportunity to discuss the SAB Residual
Risk review message with you. I look forward to your questions.
______
Responses by Philip Hopke to Additional Questions from Senator Baucus
Question 1. Are you suggesting that we stop the residual risk
program until the quality of risk assessments can be improved or are
you saying that, with some additional effort, this program will work?
If you agree with the former point, when will we know whether the
appropriate level of quality has been reached to justify regulating?
Response. I believe that adequate quality residual risk assessment
can be performed, but that some additional effort will be needed to
perform them at a reasonable level of sophistication. The purpose of
the residual risk assessment is to be ascertain with a reasonable level
of certainty that no undue risk remains after MACT is put in place. The
keys are to be able to use what data and other information that are
currently available to make it clear that a sensible approach is being
taken to estimate the risks. The scientific community wants to make
sure that all of the details are dealt with as best we know how so when
we observe that there are insufficient resources to poll EPA's own data
base to compare modeling results with measurements, we feel that there
is something wrong with the process.
There will never be perfect models, but we want to use the best
model possible. When the choice is between an unreviewed model
developed for another purpose and a general use model like the Total
Risk Integrated Methodology (TRIM) that received favorable initial
reviews because it tries to provide a more complete picture of reality,
it makes sense to vigorously complete TRIM rather than continuing to
use the more limited model. It bothered our committee that there was
not a clear commitment to get TRIM into service as quickly as
practical.
It also did not appear there was a clear plan about how to deal
with toxic species for which quantitative dose/response data are
available. We are not advocating expensive toxicological testing, but
we do believe that some focused structure/activity relationship
calculations could set some credible upper bounds on the risks for
these untested species.
Thus, the major problems we saw with the process did not require
major new efforts but rather the ability to utilize data EPA already
had on hand, the Agency's ability to complete the model development and
testing they already had underway, and their ability to provide a
logical framework to deal with the toxic species for which quantitative
data are not and will not be available. We envisioned that a reasonable
increase in effort could ameliorate these problems.
Question 2. Do you have any idea of the resources that might be
necessary for it to work well?
Response. I do not have a specific dollar figure as I am not sure
of typical contractor (researcher?, model developer?) costs. However,
there is also added value for these costs. For example, the EPA has a
variety of uses awaiting the completion of TRIM and thus, the value in
completing and testing this model provides a much greater benefit than
for the residual risk program alone. I would anticipate that a modest
calculational chemistry effort with an appropriate academic group could
provide the unit risk estimates for the unmeasured dose/response
values. Given the risk reduction that can be reasonably anticipated as
coming from MACT, it is sensible to limit the costs associated with the
residual risk estimation. However, given the costs to implement MACT,
the regulated industries as well as the potentially exposed individuals
should be able to have reasonable confidence in the results of the
analysis.
Question 3. During the hearing, I believe you indicated that
``Congress should clarify how good is good enough,'' in terms of the
quality of the risk assessments for further regulation. Does that mean
that you advocate amendments to the Clean Air Act to provide such
clarification?
Response. Yes. It is hard for those involved in the risk assessment
to determine the level of assessment needed as the basis of regulatory
decisionmaking. Our natural inclination is always to do the most
detailed and quantitative analysis possible. However, that is likely to
be more detailed, more precise and far more costly than is needed for
the purpose of determining if further controls are needed to protect
the health of those living in the vicinity of such facilities. Clearly,
EPA has a view of how much effort is needed based on their perception
of the development of the 1990 Amendments. However, since there is no
clear record of what was intended at that time, it is hard for people
coming into the process to decide how much effort and rigor are
required. Thus, a clearer view of the political context of the risk
assessment process would be helpful to everyone involved in the
accomplishment and review of this task.
______
Responses by Philip Hopke to Additional Questions from Senator Smith
Question 1. Are the SAB's recommendations for residual risk
assessment, such as inclusion of ecosystem risk assessment, population
risks, etc., . . . , also valid for conducting ``comparative risk
assessment''?
Response. Yes, we certainly want to understand the risks to the
broader population as well as to the most highly exposed individuals.
It is also important to judge the ecosystem risks. Clearly, the public
values all of these factors. The relative ranking of these different
risks, however, is a management decision that needs to take other
factors into consideration in coming to decisions. There is no simple
scale of comparability between risks to individuals, to populations,
and to ecosystems that would permit an approach to ranking overall
risks. They must all be included in the evaluation of the options in
order to make the most well informed decision possible.
Question 2. Dr. Lippmann testified that a major part of the problem
with the current EPA risk assessment stems from having 2 very different
cultures of risk assessment: (1) for carcinogens and (2) for other
toxicants. Are your findings consistent with this being the source of
the problem?
Response. I think the problems are more complex than simply culture
differences within the Agency and come back to some of the discussion
we had at the hearing regarding the stovepipe approach that governs
much of the Agency's organization and practice. For example, lead in
airborne particles is a criteria pollutant for which a National Ambient
Air Quality Standard is defined under Title I while according to the
Clean Air Act, lead compounds are hazardous air pollutants under Title
III. We need to take a more holistic view of the specific problem of
air quality and the broader issues of environmental quality management.
To a significant extent such a major change in conceptualization must
come from Congress since the natural tendency of the Agency will always
be to organize around major facets of the governing legislation.
Some of the problems associated with the risk assessment process
stem from differences in the level of information available to the risk
assessor. There is a much richer data base for possible health impacts
of ambient pollutants like the criteria pollutants. The data regarding
cancer risks is much more limited. As we obtain a better understanding
of the molecular basis for cancer, some of this data disparity will be
eliminated, but that will take some time. The question then arises as
to how conservative we feel we need to be in estimating the risks and
how well these assumptions that are made in conservative risk
assessments are explained and justified to the regulated industries and
the public.
With respect to our findings concerning the residual risk process,
I do not think this dichotomy of information availability is the
problem. The problem is more related to the lack of clarity in defining
how confident in the quantitative results the Agency need to be in
order to make regulatory decisions and what needs to be done in order
to attain such quality of results. In the absence of this definition,
reviewers typically will demand more detail and the highest level of
analysis in order to minimize the uncertainties.
Statement of Felice Stadler, National Policy Coordinator, National
Wildlife Federation's Clean the Rain Campaign
Thank you, Mr. Chairman, for providing me the opportunity today to
submit comments on the U.S. Environmental Protection Agency's residual
risk program.
My name is Felice Stadler, and I coordinate the National Wildlife
Federation's national Clean the Rain Campaign. The campaign seeks to
raise public awareness about how toxic air pollution contaminates our
lakes and streams and advocate for national and local policies to
phaseout the emissions of mercury and other persistent bioaccumulative
toxics. In my testimony this morning I will explain why emissions of
toxic air pollutants must be reduced by residual risk standards. While
we recognize that EPA needs to refine its methodology for performing
residual risk assessments, we firmly believe that the program must be
preserved and adequate resources be provided to allow the agency to do
the critical assessments needed to protect humans and wildlife from
actual harm.
This is a timely subject. As you know, mercury is a highly potent
neurotoxin. Just 2 weeks ago, the National Wildlife Federation released
a report showing that mercury levels in New England's rain are up to
four times as high as EPA's standard for aquatic life in surface
waters. One year ago, the National Wildlife Federation released a
similar report showing even higher mercury concentrations in rain
falling on Great Lakes states. When mercury-laden rain falls into
lakes, it contaminates the water, the fish and other aquatic life
living in the water, and the people and wildlife who eat the fish. This
example illustrates the importance of reducing the emissions of toxic
air pollutants that are daily contaminating our rain, our lakes, our
fish and our children.
As you are aware, Congress amended the Clean Air Act in 1990 to
establish a more effective program to reduce toxic air pollution.
Congress required major sources that emit any of 188 listed toxic air
pollutants to meet performance standards based on the best industry
practices to minimize toxic releases.
Over the past decade, we have witnessed a significant reduction in
toxic air pollution emitted by large and small industry throughout the
United States. Over 20 technology-based rules have been finalized,
affecting over 48 categories of major industrial sources. Each year
these rules will remove approximately one million tons of over 100
different air toxics--almost 10 times greater than the reductions
achieved between 1970-1990. (U.S. EPA, 1998, Taking Toxics out of the
Air: Progress in Setting Maximum Achievable Control Technology
Standards Under the Clean Air Act, EPA/451/K-98-001)
Have those reductions solved the air toxics problem in communities
and ecosystems throughout the United States? Certainly not. People and
wildlife continue to be exposed to toxic air pollution which harms
their well-being.
I have already alluded to the contamination of our waters by
mercury. Mercury emitted into the air is the leading cause of mercury
pollution in the Nation's lakes and streams. The National Academy of
Sciences recently reported that over 60,000 children a year may be
adversely affected by exposure to mercury in the womb. Forty one states
and territories have issued formal advisories warning people to
restrict or avoid eating the fish they catch because of mercury
contamination. Scientists have documented harmful changes in
reproductive patterns in loons exposed to mercury.
Dioxin is another persistent bioaccumulative toxic air pollutant.
It is the most potent carcinogen and reproductive toxin EPA has ever
evaluated. Dioxin levels measured in food are above those that
scientists believe are harmful to people and wildlife.
Clearly, only part of the problem has been addressed, and it is
vitally important that EPA move to the next phase of its national air
toxics strategy, the residual risk program. If EPA is prevented from
implementing the risk-based element of its air toxics strategy,
significant air toxics problems will remain. There are three main
reasons to move forward with the residual risk program.
First, without a residual risk program, EPA will not be able to
address the harm from the most toxic air pollutants, those that, like
mercury and dioxins, persist and bioaccumulate in the environment. This
special class of pollutants is harmful at extremely low levels, and
uniquely harmful to people and wildlife because they become
increasingly toxic as they move up the food chain. For example, mercury
is one million times more toxic in fish than in surrounding water, so
when we eat fish we are consuming concentrated mercury. Those most
vulnerable to the effects of these toxic compounds include unborn
children, women, low-income communities, and communities of color. EPA
is not required to address the full extent of the harm posed by these
most toxic compounds through technology standards. Therefore, the
residual risk program is critical to ensure these unique risks are
appropriately addressed.
Second, EPA's technology standards do not take into account the
cumulative risk that occurs when industrial sources are concentrated in
an area. There are hundreds of communities throughout the country that
face a disproportionate risk from exposure to toxic air pollution
because of heavy concentrations of industrial sources. In Memphis,
Tennessee, you can see sources of toxic air pollution in every
direction--a petroleum fueling station, a six-lane highway, a refinery,
a lead smelter, and a factory. Less than a block away from these
sources, there is low-income housing and a playground. Unfortunately,
this picture is not unique. Risk-based programs enable EPA to evaluate
these real life scenarios that are all too common for countless
citizens.
Third, Congress and EPA never intended the technology-based program
to address entirely all toxic emissions from all listed sources.
Technology-based standards provide the best industry can offer at the
time they are imposed, but this does not necessarily translate into
being the most stringent or comprehensive approach. In fact, when EPA
issued the proposed Portland cement kiln rule 2 years ago, EPA
announced it would evaluate the need to make the standard more
stringent to address mercury emissions as part of the residual risk
phase.
It is EPA's tentative conclusion, however, that concerns as to
health risks from mercury emissions from these sources may be
appropriately addressed pursuant to the timetable set out in the Act,
namely through the residual risk determination process set out in
section 112(f) of the Act. 63 Fed. Reg. 14202.
The residual risk program allows the agency to revisit a regulatory
decision once more information has been collected and the effect of the
initial rule has been evaluated. Without the residual risk program,
this category of sources, and others like it, would likely never be
adequately regulated under the Clean Air Act.
In conclusion, I want to raise the issue of uncertainties relating
to the residual risk program. Every risk assessment must contend with
uncertainties--who is exposed, how much they are exposed to, the health
effects of pollutants. Requiring every uncertainty to be addressed
before taking action would effectively mean no action will be taken.
EPA is refining its tools to carry out the residual risk program, and
should be given the opportunity to go forward and implement the
program. But policy paralysis will be the result if EPA is required to
address every uncertainty before acting; our children will be the most
directly affected by delay.
Finally, I would like to close with two recommendations to improve
how we regulate sources of air toxics. First, the risks to people and
wildlife from the most toxic pollutants--those like mercury and dioxins
that bioaccumulate and persist--are well established: any release of
these pollutants causes harm. For that reason, in international
agreements the United States has committed to ``virtual elimination''
of these pollutants. To properly address the unique risks posed by
these pollutants, EPA need not engage in complicated risk analysis;
instead, it simply needs to set a schedule for phasing out the
emissions of these chemicals from all sources, and then apply
progressively lower emissions standards to meet that goal.
Second, rather than merely relying on pollution controls to solve
the Nation's air toxics problem, we urge Congress and the agency to
look at solutions that encompass pollution prevention. This applies to
both the technology-based program and the residual risk program. EPA
has the tendency to assume that all pollution is unavoidable and that
bolting on technology will solve the problem. Instead, it is time for
EPA to begin to assess what pollution could be avoided altogether and
develop policies that reflect a commitment to more sustainable and less
toxic solutions.
I thank the committee for inviting me to testify and welcome the
opportunity to answer any questions.
______
Responses by Felice Stadler to Additional Questions from Senator Smith
Question 1. Do you agree with the SAB's recommendations to improve
the EPA's risk assessment?
Response. Yes. We agree that EPA could improve upon its risk
assessment, especially its analysis of ecological impacts. However, we
would reiterate the overarching comment made by the Chair of the SAB:
with adequate resources, EPA could overcome several of the limitations
noted, including data collection and refinement of analyses.
Question 2. Does the public, in your opinion, benefit from
participating in a CRA project?
Response. Yes. It is essential for the public to have the
opportunity to participate in comparative risk assessment projects,
especially those conducted on the State or local level. Because the
process itself is strongly value laden, all stakeholders should have an
opportunity to provide input on how to prioritize issues of concern.
Local communities are at the front lines of the pollution problem, and
often do not have the resources to become engaged in policy discussions
at the State or Federal level. Any dialog that takes place that
determines which risks become a priority must involve communities most
directly affected by those decisions.
In general, NWF does not endorse using CRA's to drive policy
decisions. While intellectually this technique has some appeal, it
raises a lot of questions and concerns. For example, how easy is it to
compare two different types of activities (air emissions vs. water
discharges), one chemical to another (benzene vs. mercury), one health
endpoint to another (neurodevelopmental effects vs. cancer). In
addition, CRA's would result in key questions never getting raised,
questions of responsibility: Who is responsible for the pollution? Can
the pollution be prevented? What tools are available to reduce the
pollution? These questions are critically important and must be central
to any pollution policy decisions.
Question 3. Some have criticized EPA's risk assessments, saying
that they are too conservative. Do you believe that to be the case?
Response. No. The SAB did not consider conservative modeling to be
inherently improper, either. Rather, it was concerned that EPA failed
to validate conservative modeling by checking predicted outcomes
against known outcomes.
We support the use of conservative modeling. Policy decisions
should be made with the information at hand, rather than delaying
action in the face of uncertainty. We will never have the luxury of
knowing the answer to every scientific question before needing to act.
In fact, EPA does not always use conservative assumptions. EPA has
been criticized repeatedly for designing risk assessment models based
on what is safe for healthy, adult, white men. For this reason, EPA
needs to be conservative in order to avoid underestimating risks to the
most vulnerable populations children, the unborn, women, elderly, and
people in overburdened communities.
Moreover, EPA does not appear to be using conservative assumptions
with respect to non-carcinogenic HAPs, which may make the risks posed
by carcinogenic HAPs seem greater. EPA should address the disparity in
the treatment of carcinogenic and non-carcinogenic HAPs in two ways.
First, EPA should assess the risks of the most harmful non-carcinogenic
HAPs persistent, bioaccumulative toxic substances, such as mercury--
using assumptions that are no less conservative than those used in
assessing the risks of carcinogenic HAPs. Second, as the SAB
recommended, EPA should develop and make greater use of uncertainty and
variability (``U&V'') analyses. U&V analyses can be used to compare and
adjust the results of conservative and non-conservative risk
assessments.
In sum, using conservative assumptions and modeling is not
inherently inappropriate because we are dealing with HAPs, which are
causing real harm not merely creating a risk of harm to human health
and environmental integrity.
Question 4. Some of the witnesses have indicated that Congress
needs to step in to provide EPA additional time prior to requiring
regulations to reduce residual risk. Their main reasons for proposing a
delay are the quality of risk assessments, the lack of sufficient
resources to conduct these assessments, and the need for Congress to
clarify what it considers to be a good risk assessment. What are your
views on these reasons?
Response. EPA is making a concerted effort to refine its risk
assessments in order to meet the deadlines imposed by the Clean Air
Act. Any delay of those deadlines will result in prolonged exposure to
HAPs. Rather than extend the deadlines, then, Congress should focus on
fully funding EPA's air toxics program. Congress is currently not doing
this, which impairs and inhibits the quality and speed with which the
agency can complete its initial screening assessments and its detailed
risk assessments.
Congress should not attempt to delve into the scientific
complexities of residual risk by trying to clarify what constitutes
``good risk assessment.'' The field of risk assessment is continually
evolving in scientific circles, and EPA is working to track these
developments and update its methodology to reflect the new approaches
that are emerging. Congress does not have the expertise to determine
whether EPA's risk assessment is sound. If Congress is interested in
the evolving science of risk assessment, we respectfully suggest it
should request annual briefings from EPA on this subject.
Question 5. Would NWF support requiring HAP emitters to provide
financial support for conducting residual risk assessments?
Response. NWF would support such a requirement only if HAP emitters
do not receive in exchange any influence over the design or performance
of the assessments. Furthermore, should EPA choose to contract with an
independent firm to conduct an assessment, EPA must first screen the
firm to ensure the absence of any conflict of interest, and must
closely oversee the guidelines and protocols the firm uses.
Allowing a single source or a category of HAP emitters to conduct
residual risk assessments for their own facilities would be
problematic. As you heard at the Senate hearing, issues like
uncertainty are often driven by values and priorities rather than
scientific justification. Given this fact, a risk assessment conducted
by a HAP emitter would be suspect.
In addition, a risk assessment conducted by a single source likely
would not take into account the impact of pollution from neighboring
sources. It would look only at emissions at its own fence line.
Cumulative exposures are critically important and must be addressed
through the residual risk program.
Question 6. You mentioned some of the flaws associated with the
existing process by which EPA assesses risk--the lack of consideration
of cumulative risk, transgenerational risk, etc. How could EPA improve
its process?
Response. EPA could begin to improve its process by setting clear
priorities based on the type of pollutants being emitted. Toxic
compounds that bioaccumulate and persist in the environment, that
contaminate our food supply, that are easily passed from mother to
child, and that damage critical organ systems, should be phased out.
EPA could simplify its risk assessment approach and make policy
decisions based on the inherent toxicity of this special class of HAPs,
concluding that they should be handled differently.
In terms of addressing cumulative risk, for compounds that are both
air and water contaminants, and possibly food contaminants, EPA must
consider all these different routes of exposure when calculating risk.
Evaluating the risk of inhalation alone is inadequate. If EPA's air
division does not address multi-pathway exposures in its risk
assessment, and if there is evidence that other routes of exposure are
likely, the inhalation risk level should serve as the floor rather than
the ceiling. In this case, we would argue that the most conservative
minimum risk level one in one million should be used for cancer and
non-cancer effects to protect the most vulnerable populations.
__________
Statement of George E. Parris, Ph.D., Director, Environmental and
Regulatory Affairs, American Wood Preservers Institute
preface
We are honored to address the Senate Committee on Environment and
Public Works. We are also honored to speak for the American Wood
Preservers Institute, which represents an industry of many small
businesses that has been instrumental in the economic growth of this
country by making railroads, marine shipping, rural electric utilities,
telecommunications and house construction economically feasible while
conserving our forest resources.
The American Wood Preservers Institute strongly supports the use of
quantitative risk assessment and risk-cost-benefit analyses in
regulatory decisionmaking. Without these inputs from the real world,
regulatory decisions would be based on intuition and political
considerations. However, the risk assessment methodology is evolving
and must reflect our current understanding of science; and the cost and
benefits analyses must consider both direct and indirect impacts
(inside and outside the regulated community). When applied objectively,
risk assessment and risk-cost-benefit analyses are the foundation of
rational policy, regulations, and standards. Unfortunately, when
obsolete risk assessment techniques are applied and cost and benefits
are selectively chosen for consideration, politically motivated policy,
regulations and standards can masquerade as being unbiased and
rational.
part i. the role and value of risk-cost-benefit analysis in
decisionmaking
The regulations and standards for protection of human health and
the environment that are promulgated to implement environmental
statutes (1) must use scientifically valid methodologies, (2) must be
applied consistently so that decisionmakers apply finite resources in
the most efficient way, and (3) must be reasonable in terms of
balancing risks, costs and benefits (i.e., they must meet a reasonable
threshold of utility).
The Congress (not bureaucrats or political appointees of the
Executive branch) must set broad policy guidelines for (1) acceptable
risk, (2) equitable allocation of finite resources to reduce risks, and
(3) minimum requirements for risk reduction per unit of money spent by
government or the private sector to justify action.
The wood preserving industry provides examples of the types of
problems that we believe are currently common in environmental laws,
regulations, standards, and enforcement policies. I will address some
of these here:
part ii. the methodology of risk assessment must be scientifically
valid
The risk of contracting fatal cancer underpins of most of our
environmental standards and the public perception of risk of many
activities and products. Since most of the communicable diseases that
killed millions of children and adults in previous generations have
been tamed by better hygiene and antibiotics, cancer has become the
leading unpredictable and uncontrolled risk in most peoples' lives. In
turn, quantitative risk assessment methodology has been introduced to
attempt to make the risk of cancer predictable and to provide a
rational basis for control of that risk.
However, the risk assessment methodology that is still used today
was invented primarily between 1930 and 1970 at a time when our
understanding of the nature and cause of cancer was very rudimentary. I
want to briefly recount the history of our quantitative risk assessment
methodology and show how it needs to be changed to reflect current
scientific knowledge in biochemistry and genetics (see appendix).
It should be noted that the regulatory agencies have clung
tenaciously to the original concepts in spite of growing evidence that
they are inapplicable in most cases. The exercise of prudence is
certainly a desirable trait in a regulatory agency, but the credibility
of the regulatory agencies (particularly the U.S. Environmental
Protection Agency) is being eroded among knowledgeable observers
because they are currently so far behind the state-of-the-art.
My industry is currently affected by EPA risk assessments for
dioxins and arsenic. We believe that the methodology used in these risk
assessments is fundamentally flawed (as discussed below) resulting in
risk projections that are so large that the EPA is being led to actions
which will unnecessarily limit the use of our products and which will
cause unnecessary alarm in the general public.
Clearly Many Carcinogens Should Not be Assessed by the Target Theory
(1) The Fundamental Requirement of the Target Theory is Not
Met
The fundamental requirement of the target theory (linear no-
threshold [LNT] model) of mutagenicity/carcinogenicity is direct damage
to the DNA independent of any biochemical system. Few chemicals have
been shown to directly damage (e.g., form adducts with) DNA. Some
chemicals have been shown to form adducts with DNA after being
metabolized to active electrophiles or free radicals. Unless, such
reactions are demonstrated in vitro, there is no scientific
justification for applying the target theory (linear no-threshold
model) of risk assessment.
(2) The Target Theory Ignores Chemical and Physical
Modulation of Dose
Efficiency
Most chemical and physical barriers that stand between a chemical
as dosed and the DNA target of mutation are progressively less
effective as the dose of the chemical increases. In many cases, there
may be a threshold below which a chemical agent never reaches the DNA.
Thus, we would expect most dose response curves to be non-linear, i.e.,
sub-linear.
(3) The Target Theory Ignores DNA Repair
The existence of DNA repair mechanisms means that even for direct
acting genotoxic agents (e.g., x-rays), the dose-response curve should
be sub-linear at low doses. Since DNA repair occurs after a damaging
event, DNA repair would not require, an absolute threshold, but the
quantitative difference between a true threshold (i.e., zero risk) and
a sub-linear dose-response curve may be un-measurable.
(4) The Target Theory Incorrectly Assumes that Mutant Cells
Progress to
Cancer
Many cell clones in the body contain mutations, they normally do
not progress to cancer because (i) they are not immortal and hence
become extinct before clinically significant tumors develop or (ii)
they are triggered to undergo apoptosis by proteins that scan the DNA.
Most Carcinogens are Threshold Carcinogens
There are many mechanisms through which a chemical can indirectly
cause genotoxicity that leads to cancer. Even in those cases where
direct genotoxicity has been observed, indirect mechanisms may be the
principal contributor to genotoxicity at high doses. The importance of
recognizing that fact and developing our risk assessment policy around
this concept is that for those cases, there is a threshold of exposure
below which the risk is effectively zero. By managing exposures
(through appropriate regulation) such that the total exposure is below
the appropriate threshold, a very high level of health protection can
be provided with great flexibility in compliance that lead to health,
environmental and economic benefits.
In practice the thresholds can be established two ways: (1)
epidemiologically (bioassay and environmental) and (2) biochemically.
The biochemical approach involves determining in vitro threshold of
genotoxicity (it is not necessary to determine the mechanism of action)
using appropriate tissue cultures and determining what the attenuation
factor is between environmental medium and blood plasma (e.g., what
concentration in drinking water is required to give the concentration
in blood plasma equal to the genotoxic threshold determined in vitro).
part iii. the cost and benefit analyses must consider direct and
indirect impacts
(1) Comparative Risk Assessment
The Environmental Protection Agency has excused itself from
explicit compliance with the National Environmental Policy Act (NEPA)
on the grounds that rulemakings by the USEPA are equivalent to the
analysis required in an Environmental Impact Statement (EIS) under
NEPA. Unfortunately, that policy has resulted in the programs
implemented by the USEPA including the regulation of waste (RCRA),
water (SDWA), air (CAA) and remediation of environmental contamination
(CELERA) taking unexpected and undesirable directions. Basically, the
USEPA has developed implementation approaches that focus on only one
element of what is actually a multi-component situation. I will discuss
the environmental remediation program under CERCLA (Superfund) as an
example.
Basically, the decisions concerning (1) whether or not to remediate
and (2) what the target final concentration of contaminant should be
are driven either by compliance with applicable or relevant and
appropriate requirements (ARARs) or a toxicological risk assessment
that addresses the potential risk to persons who may (or may not)
actually live on the contaminated land and may (or may not) actually
drink the groundwater, etc. Notice that all the focus is on hazards and
risk caused by the chemical (usually toxicological) in the contaminated
media. Once the chemical risk (usually carcinogenic risk) to the people
who are exposed (or who may possible be exposed in the future) is
deemed to be above a target set by policy (e.g., 40 CFR 300.430) the
process is committed to a course of action that requires remediation.
There is a major flaw in this approach. Fundamentally, the
decisionmaking guided by the regulation disregards all other risks and
impacts of the proposed action. If you look at environmental
remediation projects, what you discover is that they are basically
construction projects. They involve drilling wells, pumping water,
excavating soil, hauling soil and debris from place to place (often on
public roads), construction and operation of treatment systems, etc.
Disregarding the chemical or radiological hazards to workers and the
general public associated with these projects (including the potential
hazards presented to people living near landfills where waste may be
disposed offsite), the construction work and transportation alone
represent risky operations (especially when protective clothing for
protecting workers from chemical risks are factored in because they
usually increase heat load, restrict vision and make the worker more
awkward). Construction projects, of course, also involve environmental
impacts (e.g., damage to habitat or taking of wildlife).
It would be desirable to have a more balances weighting of risk in
the CERCLA program so that the presumption that remediation is always
preferred can be analyzed.
Another example where narrow focus on one element of risk can
produce undesirable conclusions is associated with the use of wood
preservatives. For example, unnecessarily limiting the use of a wood
preservative because of erroneous risk assessments might result in the
harvesting of more trees (depletion of natural resources) and more
accidents and deaths in the logging and sawmill industry.
(2) Balancing Risks, Costs and Benefits
There should be some reasonable analysis of costs, risks and
benefits associated with regulations and standards. The wood preserving
industry has provided clear examples of poor risk-cost-benefit
decisionmaking by the USEPA. In the 1992 budget process, it was pointed
out that the hazardous waste regulations for wood preservatives cost
5.7 Trillion dollars per avoided premature death! This set a record for
inefficient use of our financial resources. Viewed differently,
spending $2 million on highway safety saves at least one life in a few
years, but spending the same amount on controlling waste from wood
preserving does not save a life over a million years. Obviously, the
benefits of such regulations are insignificant, while the costs are
very real.
In the cases of the current debate over the regulation of arsenic
in drinking water, it should be embarrassing for USEPA regulators to go
to international conferences where scientists from West Bengal and
Bangladesh describe real, widespread, overt clinical signs of chronic
arsenic intoxication from drinking water at levels of arsenic
approaching 1,000 ppb and then argue that the United States should
spend billions of dollars to reduce the concentrations of arsenic in
drinking water from 50 ppb to 5 ppb, when benefit of such a move are at
best hypothetical. The only cases that the USEPA claims show any damage
at the current regulatory standard in the U.S. are actually among
people that are not covered by the current standard and would not be
covered by the standard because they are on private wells.
Interestingly, USEPA cost estimates for implementation of the
current proposed maximum contaminant limit (MCL) for arsenic only
addresses some of the most obvious cost (e.g., treatment equipment) to
the ``regulated community'' i.e., public water utilities. The cost of
acquiring land to build a treatment plant on and the cost of waste
disposal are severely underestimated or ignored by the USEPA. Moreover,
entire classes of economic impacts are not even mentioned by the
USEPA's proposal. For example, the MCLs are routinely adopted as
applicable or relevant and appropriate requirements for CERCLA
remediation and in this way, the new MCL for arsenic will affect the
wood-treating industry.
Even private real estate values may be affected by the new arsenic
MCL. Suppose that you are a private land owner with a well with 40 ppb
of arsenic from natural sources. Currently if you sell your house,
there is no issue about the purity of the water. But, if the MCL for
arsenic were reduced to 5 ppb, you would need to disclose that your
well was ``contaminated'' to prospective buyers. Moreover, the cost to
cure this ``defect'' by installing a point-of-use treatment device will
cost (by the USEPA's estimates) several hundred dollars each month
(forever). Considering that typical mortgages (principal and interest)
are $1,000 to $2,000 per month, an additional burden of e.g., $300 per
month will necessarily reduce the value of the real estate by 15-30
percent. It implication for property values in large parts of the
western United States, Michigan, Wisconsin, Minnesota and other states
is staggering.
Ignore the proposed MCL for arsenic for a moment and focus on the
underlying risk assessment. Heretofore, the USEPA has used similar risk
assessments to estimating the risk associated with soil contamination
and pesticides residues (which have exposure scenarios that have
nothing to do with water). But, because the USEPA retained a drinking
water standard that was consistent with a much lower level of concern
about arsenic, the risk assessment per se was not burdensome. Now that
the USEPA is accepting the risk assessment as the driver for regulation
of drinking water, the implications for other modes of exposure are
enormous. The risk assessment will be used in the waste programs, the
pesticide programs, in the air programs as well as the water programs.
Finally, in the context of risk-cost-benefit analysis, I would like
to report arsenic contamination of the Madison River in Wyoming. At the
source, the concentration of arsenic is 360 micrograms per liter and
the pollution can be traced at least 470 km downstream until the
Madison River joins the Missouri River where the concentration of
arsenic is still 19 micrograms per liter. I am sure that if this were
caused by a wood preserving plant, our industry would be expected to
pay whatever cost was necessary to stop this flow of arsenic. But, the
source of the arsenic (and other toxic metals) is the Yellow Stone
National Park.
______
Appendix
history of the evolution of quantitative risk assessment for cancer
1850: LRemember that the microscope was not invented until the
early 1800's and that led to the discovery of cells and the
identification of chromosomes (i.e., condensed forms of DNA visible
under a microscope during the cycle of cell division).
1870: LThe concept of inheritable traits was introduced in the
period 1850-1870 by Gregor Mendel (1822-1884)
1890: LThe role of microbes in causing some diseases was not
understood until 1877-1887 through the work of Louis Pasture (1822-
1895)
1890: LCancer was recognized as a disease in the 1800's, but it was
not until the late 1800's that exposure to specific chemical substances
was associated with the increased incidence of some cancers.
1910: LIn the period 1890-1910 the work of Paul Ehrlich established
the concept of dose-response relationships for pharmacology and
toxicology. Much of this research also involved arsenic (III) which was
one of the few effective drugs used to treat protozoal diseases
(sleeping sickness and syphilis). Invariably, for a specified
biological end point (e.g., acute toxicity) there were thresholds below
which no effects were observed and the responses of individual members
of the exposed population tended to fall into a bell-shaped curve
(normal distribution). Integration of this bell-shaped curve produces
an S-shaped curve known as the dose-response relationship (i.e.,
probability of effects at a specific dose).
1920: LIt was not until the period 1908-1918 that chromosomes were
linked to inheritable traits and mutations by Thomas Hunt Morgan (1866-
1945).
1935: LDuring the early 1900's, radioactivity was intensely studies
including the effects of x-rays on tissue. It was observed that (within
the range of exposure considered) the frequency of mutations caused by
x-rays was linearly related to the total dose (intensity x duration)
not the intensity or the duration of exposure alone. This observation
gave rise to the erroneous idea that (for x-rays) intensity did not
matter and only the total dose needed to be considered.
1940: L``Target theory'' became the acceptable way to predict
damage to chromosomes (and hence mutations) through bombardment with
agents (such as x-rays). This was consistent with the notion held at
the time that (1) chromosomes normally were never damaged; (2) if
chromosomes became damaged, they was never repaired; and (3) any damage
to chromosomes would result in either immediate death of the cell of a
mutant cell line.
1953: LIt was not until 1953 that the structure of DNA making up
chromosomes was explained by Watson and Crick.
1961: LNormal cell clones were shown to be mortal (normally die
after a set number of replications, i.e., generations) and cancer cell
clones were shown to be immortal by Leonard Hayflick.
1962: LSilent Spring published by Rachael Carson provoking
systematic public fear of manmade chemicals.
1970: LThe process of DNA repair was discovered and articulated by
J.E. Cleaver and others while working on the cause of the inheritable
disease xeroderma pigmentosum.
1970: LThe U.S. Environmental Protection Agency was founded and
began establishing policies concerning management of risk caused by
manmade (industrial) chemicals. The target theory of mutations was
accepted and extrapolated in two ways (i) it was applied across the
board to chemicals (not just high energy radiation) and (ii) the theory
was assumed to relate to cancer as well as mutations. Note that high-
energy radiation can go directly to chromosomes without passing through
chemical or physical defenses present in the body. Chemical agents must
pass through both chemical and physical barriers before reaching the
nucleus and the DNA.
1971: LRecombinant DNA discovered.
1972: LApoptosis (programmed death and recycling) of stressed and
damaged cells was articulated by Kerr, Wyllie and Currie.
1992: LChromosome telomere shorting during DNA synthesis related to
cell clone mortality.
2000: LFormulation of a new model for cancer risk assessment in
progress.
__________
U.S. Science Advisory Board,
May 19, 2000.
EPA-SAB-EC-ADV-00-005
Hon. Carol M. Browner, Administrator,
U.S. Environmental Protection Agency,
Washington, DC.
Re: Advisory on the USEPA's Draft Case Study Analysis of the Residual
Risk of Secondary Lead Smelters
Dear Ms. Browner: On March 1-2, 2000, the Science Advisory Board's
(SAB's) Residual Risk Subcommittee of the SAB Executive Committee
conducted a peer review of an Agency case study of the residual risk
assessment methodology, described in its Report to Congress (USEPA,
1999), as applied to the secondary lead smelter source category (USEPA,
2000). The review of the seven-volume set of material focused on eight
specific questions that are addressed in detail in the accompanying SAB
report.
In short, the Subcommittee concludes that the Agency has developed
a useful, self-described ``work-in progress''. The methodology used in
this interim workproduct, as far as it currently goes, is consistent
with the methodology described in the Report to Congress. Further, the
assumptions used are consistent with current methods and practice. The
case study provides a valuable example of how the approach presented in
the Report is going to be implemented.
However, because the Subcommittee has not yet seen a full residual
risk analysis and, thus, is unable to comment on the complete process,
a number of important concerns were identified that should be
addressed. Specifically, this interim analysis does not include the
following important elements: an ecosystem risk assessment; a health
risk assessment that includes population risks; a full analysis of
uncertainty and variability; a computer model for assessing multimedia
transport and fate that has been adequately evaluated; nor a clear
description of the process and how the assessments link to the eventual
risk management decisions. The attached consensus report contains a
discussion of a number of additional issues related to the specific
approaches taken in the interim analysis.
Looking to the future and the 173 other source categories to be
addressed in the residual risk program, the Subcommittee is concerned
about the data gaps that are likely to be even more of a problem than
they are in the case of secondary lead smelters. Both the Agency and
the Congress need to recognize this problem in order to ensure that
there is an adequate data base to support the residual risk analysis
program.
During the review by the Executive Committee, a number of important
concerns were raised that will be the subject of a subsequent SAB
Commentary. In addition, the Health and Environmental Effects
Subcommittee (HEES) of the SAB's Council on Clean Air Act Compliance
Analysis (COUNCIL) and the Agency will host a June 2000 workshop on
dealing with hazardous air pollutants (HAPs). The workshop and its
outcomes could prove useful insights that are applicable to the
implementing of the Residual Risk Program.
We appreciate the opportunity to provide advice on this effort. The
Agency staff was open, collegial, cognizant of shortcomings in the
document, and accepting of the Subcommittee's suggestions. Given the
incomplete State of the document at this time and the precedent-setting
nature of this--the first of 174--residual risk analyses, we conclude
that a peer review of the final Agency Report on secondary lead
smelters is in order. We look forward to your response.
Sincerely,
Dr. Morton Lippmann,
Interim Chair, Science Advisory Board.
Dr. Philip Hopke, Chair,
Residual Risk Subcommittee,
Science Advisory Board.
______
notice
This report has been written as part of the activities of the
Science Advisory Board, a public advisory group providing extramural
scientific information and advice to the Administrator and other
officials of the U.S. Environmental Protection Agency. The Board is
structured to provide balanced, expert assessment of scientific matters
related to problems facing the Agency. This report has not been
reviewed for approval by the Agency and, hence, the contents of this
report do not necessarily represent the views and policies of the U.S.
Environmental Protection Agency, nor of other agencies in the executive
branch of the Federal Government, nor does mention of trade names or
commercial products constitute a recommendation for use.
Distribution and Availability: This Science Advisory Board report
is provided to the USEPA Administrator, senior Agency management,
appropriate program staff, interested members of the public, and is
posed on the SAB website (www.epa.gov/sab). Information on its
availability is also provided in the SAB's monthly newsletter
(Happenings at the Science Advisory Board). Additional copies and
further information are available from the SAB Staff.
SAB Advisory on the USEPA's Draft Case Study Analysis of the Residual
Risk of Secondary Lead Smelters, Prepared by the Residual Risk
Subcommittee of the Science Advisory Board
residual risk subcommittee members: secondary lead smelters
SAB Members*
Dr. Philip Hopke, Department of Chemistry, Clarkson University,
Potsdam, NY (Chair), Member: SAB's Clean Air Science Advisory
Committee; Dr. Stephen L. Brown, Risks of Radiation Chemical Compounds
(R2C2), Oakland, CA, Member: SAB's Research Strategies Advisory
Committee, SAB's Radiation Advisory Committee; Dr. Michael J.
McFarland, Engineering Department, Utah State University, River
Heights, UT, Member: SAB's Environmental Engineering Committee; Dr.
Paulette Middleton, RAND Ctr for Env Sciences & Policy, Boulder, CO,
Member: SAB's Advisory Council on Clean Air Act Compliance Analysis;
Dr. Jerome Nriagu, School of Public Health, University of Michigan, Ann
Arbor, MI, Member: SAB's Integrated Human Exposure Committee.
SAB Consultants*
Dr. Gregory Biddinger, Exxon-Mobil Company, Fairfax, VA; Dr.
Deborah Cory-Slechta, Department of Environmental Medicine, University
of Rochester, Rochester, NY; Dr. Thomas J. Gentile, New York State Dept
of Environmental Conservation, Albany, NY; Dr. Dale Hattis, Clark
University, Worcester, MA; Dr. George E. Taylor, Biology Department,
George Mason University, Fairfax, VA; Dr. Valerie Thomas, Center for
Energy and Environmental Studies, Princeton University, Princeton, NJ;
Dr. Rae Zimmerman, Robert Wagner Graduate School of Public Service, New
York University, New York, NY
Science Advisory Board Staff*
---------------------------------------------------------------------------
* Members of this SAB Subcommittee consist of: (a) SAB Members:
Experts appointed by the Administrator to 2-year terms to serve on one
of the 10 SAB Standing Committee; and (b) SAB Consultants: Experts
appointed by the SAB Staff Director to a 1-year term to serve on ad hoc
Panels formed to address a particular issue; in this case, the
application of the Agency's Residual Risk Policy to the case of
secondary lead smelters.
---------------------------------------------------------------------------
Dr. Donald G. Barnes, Designated Federal Officer, U.S.
Environmental Protection Agency Science Advisory Board (1400A), 1200
Pennsylvania Avenue, Washington, DC 20460; Ms. Priscilla Tillery-
Gadson, Management Associate, U.S. Environmental Protection Agency
Science Advisory Board (1400A), 1200 Pennsylvania Avenue, Washington,
DC 20460; Ms. Betty Fortune, Management Assistant, U.S. Environmental
Protection Agency Science Advisory Board (1400A), 1200 Pennsylvania
Avenue, Washington, DC 20460
______
1. Executive Summary
On March 1-2, 2000, the Science Advisory Board's (SAB's) Residual
Risk Subcommittee of the SAB Executive Committee conducted a peer
review of an Agency draft case study of the residual risk assessment
methodology, as described in its Report to Congress (USEPA, 1999), as
applied to the secondary lead smelter source category (USEPA, 2000).
The SAB understands that the Agency plans another iteration, including
additional data collection and analysis before the results are
considered for use in a regulatory contexts. The review of the seven-
volume set of material focused on eight specific questions that are
addressed in detail in the accompanying SAB report.
In short, the Subcommittee concludes that the Agency has developed
a useful, self-described ``work-in progress''. The methodology used in
this interim workproduct, as far as it currently goes, is consistent
with the methodology described in the Report to Congress. Further, the
assumptions used are consistent with current methods and practice. The
case study provides a valuable example of how the approach presented in
the Report is going to be implemented.
However, because the Subcommittee has not yet seen a full residual
risk analysis and, thus, is unable to comment on the complete process,
a number of important concerns were identified that should be
addressed. Specifically, this interim analysis does not include the
following important elements: an ecosystem risk assessment; a health
risk assessment that includes population risks; a full analysis of
uncertainty and variability; a computer model for assessing multimedia
transport and fate that has been adequately evaluated; nor a clear
description of the process and how the assessments link to the eventual
risk management decisions. With respect to the specific approaches
taken in the interim analysis, a number of questions are discussed in
detail in the attached consensus report.
One of the greatest shortcomings of the case study in its
incomplete State is that only the first stage screening analysis has
been done for the ecological risk assessment. While the Office of Air
Quality Planning and Standards (OAQPS) recognizes that a full risk
assessment is needed, the Subcommittee is disappointed at the pace at
which the assessment is being developed and implemented for ecology and
natural resources. It would appear that a more concerted and
scientifically sound analysis is needed in order to meet the mandate of
the Clean Air Act Amendments (CAAA).
Regarding the health risk assessment portion of the case study, the
Subcommittee finds that, within the limitations of data and resources,
the approaches employed by the Agency were able to qualitatively
identify potentially high human health risk situations. However, the
Subcommittee also concluded that the currently available science is
insufficient to be comfortable with the quantitative values estimated
by these models. In particular, the analysis calls into question the
ability of the model to reliably quantify the amount of the deposited
contaminant that is transferred to the food chain. In addition, the
current risk assessment will have to be further developed in order to
include population risks if it is to meet the needs of the Agency.
The lack of a more rigorous treatment of uncertainty and
variability may lend an aura of precision to the risk estimates in the
case study that may not be warranted and could, thereby, be misleading
for Agency decisionmakers. In particular, the uncertainty analysis does
not consider the propagation of uncertainties of the model parameters
throughout the analysis.
In the case of multimedia computer models, the Subcommittee is
concerned about the extent to which such models were applied without
due consideration of the plausibility of the assumptions and the
physical meaning of the results. There should be an iterative process
in which implausible results flag problem areas, so that the Agency can
make appropriate revisions in the model and/or its inputs, and the
model run again. A number of plausibility checks were described by the
Subcommittee and in public comments that would provide checkpoints in
the analysis and, thereby, indicate the need for alternative
assumptions and recalculation. Inclusion of these checkpoints would be
helpful to both the Agency and the reader.
Finally, an overarching comment is that the case study should
provide more details of what was done, how it was accomplished, and how
the results link to the eventual risk management decisions. It is
critical that the process be described as clearly as possible,
especially articulating why particular choices were made at various
decision points in the risk analysis. The current document is lacking
in this regard.
Moving beyond the strictly technical aspects of the document on
which the SAB has been asked to provide advice, the Subcommittee would
like to comment on what it understands is the Agency's intention to
make decisions based on these results. Specifically, the Agency is
mandated under Section 112(f) of the Clean Air Act to conduct the
residual risk assessment and to make a decision about whether or not
further regulation is necessary in order to protect public health and
the environment. In particular, as stated in the Agency's response to
the previous SAB review of the Report To Congress (SAB-EC-98-013),
``the decision made with the results of the screening analysis is
[either] no further action or refine the analysis, while the decision
made with the results of the more refined analysis is [either] no
further action or consider additional emissions control.'' As discussed
above, the Subcommittee concludes that, as the currently presented, the
results of the refined analysis provide the same answer as the initial
screening analysis; that is, they will not suffice as a basis for risk-
based rulemaking, and, therefore, an even more refined analysis is
needed. Therefore, the case study, at this stage, has not achieved its
decision objective, and another level of analysis or iteration is
needed. A better-informed decision will be possible if the results of
the case study more fully reflect the inability to define the risks
more precisely.
Outside the bounds of this particular analysis, the Subcommittee
expressed two broader concerns regarding future assessments. First, the
present source category, secondary lead smelters, is relatively data-
rich. Because of the existence of the lead National Ambient Air Quality
Standard (NAAQS) and the concern for blood lead levels in children,
there are more data in the vicinity of facilities of this source
category than are likely to be available for other HAPs from other
types of sources. For many or most other source categories, the number
of HAPs and the number of source types, coupled with the limited data
on emissions and quantitative information on health and ecological
effects, makes the residual risk task substantial.
Second, while the basic Congressional approach of imposing controls
and assessing residual risk of remaining HAPs emissions makes sense, in
concept, it appears that there have not been sufficient resources
provided to collect and assess all of the pertinent data from state/
local air quality and public health agencies that could be fruitfully
brought to bear on this problem. There are certainly not sufficient
resources to permit the testing of specific HAPs for their toxicity if
those dose-response data are not already available. In the case of
secondary lead smelters, only seven of the 50 identified HAPs were
excluded from the residual risk assessment due to the lack of dose-
response data. However, lack of data will likely pose much greater
problems when other source categories are addressed in the future. Such
data gaps could lead to the omission of compounds from the assessment,
resulting in a subsequent underestimation of the residual risk.
Appropriate recognition of this problem is needed by both Congress and
the Agency in order to develop an adequate data base to support the
residual risk analysis program.
2. introduction
2.1 Background
Section 112(f)(1) of the Clean Air Act (CAA), as amended, directs
ERA to prepare a Residual Risk Report to Congress (RTC) that describes
the methods to be used in assessing the risk remaining, (i.e., the
residual risk) after maximum achievable control technology (MACT)
standards, applicable to emissions sources of hazardous air pollutants
(HAPs), have been promulgated under Section 112(d). The RTC was
intended to present EPA's proposed strategy for dealing with the issue
of residual risk and reflected consideration of technical
recommendations in reports by the National Research Council [''Science
and Judgment''] (NRC, 1994) and the Commission on Risk Assessment and
Risk Management (CRARM, 1997). As a strategy document, the Agency's RTC
described general directions, rather than prescribed procedures. The
announced intent was to provide a clear indication of the Agency's
plans, while retaining sufficient flexibility that the program can
incorporate changes in risk assessment methodologies that will evolve
during the 10-year lifetime of the residual risk program.
In 1998, the SAB conducted a formal review (SAB, 1998b) of the
draft RTC (USEPA, 1998) and its proposed methodology. In their review,
the SAB noted that it was difficult to assess the Agency's methodology
without first seeing it applied to a specific case.
In the summer of 1999, the Agency asked the SAB to provide advice
on the application of the residual risk methodology to the specific
case of lead smelters. This source category was selected since it was
relatively small (fewer than 30 facilities nationwide) and data rich.
2.2 Charge
In the months leading up to the SAB meeting, the Agency and the
Board negotiated a Charge consisting of the eight questions below.
(a) Overall.--Is the methodology that the Agency applied in this
risk assessment consistent with the risk assessment approach and
methodology presented in the Report to Congress? (EPA-453/R-99-001)?
Are the assumptions used in this risk assessment consistent with
current methods and practices?
(b) Model Inputs.--Are the methods used to estimate emission rates,
and the method used to estimate species at the stack appropriate and
clearly described?
(c) Models.--Does the risk assessment use appropriate currently
available dispersion models both at the screening level and at the more
refined level of analysis? Are the models applied correctly? Given the
State of the science, does the risk assessment use an appropriate
multi-pathway model? The assessment uses the IEM-2M model, with some
modifications. Is the IEM-2M model appropriate for use in this
regulatory context? With regard to the modification and application of
the model, did the EPA appropriately modify the model for use in this
risk assessment, and did the Agency apply the model correctly? Is there
another model or another approach that is available at this time that
EPA should consider?
(d) Choice of Receptors.--The Agency identifies the home gardener
as the appropriate receptor to estimate risks to the residential
population and the farmer to embody high end risks. Are these receptors
appropriate for this task?
(e) Ecological Risk Assessment.--Given currently available methods,
are the models used for the ecological assessment appropriate? Are they
applied correctly? Are the ecological benchmarks appropriate?
(f) Health Risk Assessment.--Section 3.4.1 of the Report to
Congress identifies several data sources that the Agency would draw
upon for choosing dose-response assessments to be used in residual risk
assessments. The Report also states that EPA will develop a hierarchy
for using such sources. Given available dose-response information, is
the hierarchy presented in this assessment appropriate (see especially
footnote #6, section 2.2.1)? For each chemical included in the
assessment, is the choice of dose-response assessment appropriate? Are
the dose-response assessments appropriately incorporated into the
assessment?
(g) Uncertainty and Variability Assessment.--Did the assessment use
appropriate currently available methods to identify the variables and
pathways to address the uncertainty and variability assessment? Are the
methods used to quantify variability and uncertainty acceptable? Are
there other, more appropriate methods available for consideration?
(h) Presentation of Results.--Does the Agency's document clearly
present and interpret the risk results? Does it provide the appropriate
level of information? Do the figures and tables adequately present the
data? Do the formats provide for a clear understanding of the material?
The Charge guides an SAB review, but it does not constrain the
range of comments that the Subcommittee members can legitimately offer.
2.3 SAB Review Process
The SAB Subcommittee was recruited following nominations received
from SAB Members and Consultants, the Agency, and outside
organizations. The group met in public session on March 1-2, 2000 at
the main auditorium of the USEPA Environmental Research Center in
Research Triangle Park, NC. Written comments prepared before and after
the meeting by Subcommittee members, and made available at the meeting,
form the basis for this report. Individual comments are included in
Appendix A for the edification of the Agency as an illustration of the
issues identified by the Subcommittee members and of the range of views
expressed. Those comments are not a part of the consensus report. A
more detailed description of the SAB process for this review can be
found in Appendix B.
3. responses to specific charge questions
3.1 Charge Question 1: Overall
Is the methodology that the Agency applied in this risk assessment
consistent with the risk assessment approach and methodology presented
in the Report to Congress (EPA-453/R-99-001)? Are the assumptions used
in this risk assessment consistent with current methods and practices?
The methodology presented in this report is consistent with the
Report to Congress, as far as it currently goes, and many of the
assumptions are consistent with current methods and practice. However,
the Subcommittee has not yet seen a full residual risk analysis and is
unable to comment on the complete analysis process. More specifically,
this was an interim analysis that did not include such important
elements as an ecosystem risk assessment, a health risk assessment that
includes population risks, a full uncertainty and variability (U&V)
analysis, a computer model for assessing multimedia transport and fate
that has been adequately evaluated, nor a clear description of the
process and how the assessments link to the eventual risk management
decisions. At this interim stage, it looks only at four of the 23
sources from the secondary lead smelters category. Nonetheless, the
report does provide a valuable indication of how the approach presented
in the Report to Congress is going to be implemented in practice. With
respect to the specific approaches used in the case study, there are a
number of questions that are discussed in detail in response to the
specific charge questions below.
A general comment is that the case study should provide more
details of what was done and how it was accomplished. It is critical
that the process be as clear and fully articulated as possible. More
details are needed on how each model has been modified from prior use.
For example, it is not clear how the IEM-2M model was modified from its
prior use in the mercury assessment in order to be used for the
secondary lead smelter emissions. The interested and knowledgeable
reader should be able to follow what changes were made and understand
why such modifications were made.
There is clearly a significant problem with how fugitive emissions
are being treated. In this analysis, much of the residual risk results
from fugitive dust emissions. However, there is little direct
information in the Agency's document on how these emission rates were
modeled. In the Agency presentations at the meeting, four approaches to
modifying the fugitive emissions were provided.
It should be possible to utilize existing data to help refine the
emissions estimates. At many or most of these facilities, there are
ambient monitors generating data to determine compliance with the lead
(Pb) National Ambient Air Quality Standard (NAAQS). These data should
provide an opportunity to estimate the routine emissions around the
plant and potentially observe the differences in concentrations before
and after whatever steps were implemented to comply with the fugitive
part of the MACT standard. Information on the frequency and extent of
upset conditions at these plants could be used to supplement monitoring
data from routine operations. Anytime data are available to provide
ground truth, the Agency should compare those data to the model
results. This feedback approach would mitigate against the generation
of results that appear unreasonable.
A number of concerns were raised about the manner in which the
models appear to have been applied without adequate consideration of
the plausibility of the assumptions or the physical meaning of the
results. An iterative process is needed in which, even in the absence
of external comparison data, when implausible results are obtained, the
model inputs can be appropriately revised and the model run again. For
example, when excessively high blood lead levels are estimated (e.g.,
200 g/dL), the analyst should reexamine the model inputs and
make appropriate modifications. Similarly, where excessively low breast
milk contaminant levels were estimated, the analyst should also
reexamine the models. A number of such plausibility checks were
described by the Subcommittee or in public comments that can provide
checkpoints in the analysis to indicate the need for alternative
assumptions and recalculation. The resulting discussion of these
implausible results and the changes made to the calculation would be a
useful modification to the current approach.
Only the first stage screening for potential hazard was available
for consideration of the ecological risk. It is recognized by OAQPS
that a full assessment of ecological risk is needed, but the rate of
progress in this direction has been slow. The methods and supporting
assumptions made are general, at best, and would need to be more
definitively treated in a refined ecological risk assessment (See
Charge Question 5 for more details). The Agency should devote
sufficient effort and resources to insure a credible ecological risk
assessment for this prototypic case study.
One of the critical problems for future residual risk analyses will
be the availability of data. Secondary lead smelters emit lead and
other HAPs. Emissions and related ambient monitoring data for lead are
generally available. Data on the other HAPs are less available, making
future assessments of residual risk associated with these other HAPs
more of a challenge. Even when data are available, the data will need
to be evaluated to determine their appropriateness for ground-truthing
risk estimates. In addition, there is a significant question about how
available are the critical input data needed to credibly characterize
the residual risks from the other 173 source categories. In the present
analysis, missing information, such as the toxicity of a number of
HAPs, led to those compounds being excluded from the analysis. There
may be molecular modeling approaches (e.g., Quantitative Structure-
Activity Relationships (QSAR)) that would permit estimation of relative
toxicity of the organic HAP compounds for which data are not available
and a screening analysis of their likely effect on the overall risks
could possibly be developed.
The Subcommittee felt that, within the limitations of data and
resources, the approaches adopted were able to identify potential high
human health risk situations. However, they also felt that the science
is insufficient to be fully confident in the quantitative values
estimated by these models. There are significant concerns regarding the
nature of the full ecological risk assessment because a complete
analysis has not yet been presented. There is concern that the apparent
precision of the resulting risk estimates may be overstated and that
more effort is needed to present results that better reflect the
uncertainties and variability in the analysis. The review material did
not give a clear picture of how the results of the analysis would be
used in the risk management process. Such information would have helped
the Subcommittee to comment more precisely on the adequacy of the
analytic results to support the decisionmaking process.
In any event, it is recognized that at some point management
decisions will have to be made based on results stemming from analyses
of this type. The Agency is mandated under Section 112(f) to conduct
the residual risk assessment and to make a decision to implement
further regulation or to make a decision that no further regulation is
needed. In response to the previous SAB review (SAB, 1998b) of the
Report to Congress, the Agency responded that, ``the decision made with
the results of the screening analysis is [either] no further action or
refine the analysis, while the decision made with the results of the
more refined analysis is [either] no further action or consider
additional emissions control.'' As discussed above, the results of the
more refined analysis provides the same answer as the initial
inhalation screen; that is, an even more refined analysis is needed.
Therefore, the case study, in its current state, has not achieved the
decision objective, and another level of analysis or iteration would be
needed. The case study needs better quality input data/estimates on
fugitive emissions, a more in-depth and refined analysis, a clearer
presentation of the steps taken in the analysis and the results
produced, and a more serious effort to fully integrate uncertainty and
variability into the analysis. In summary, a better-informed decision
will be possible if the results of the case study more fully reflect
the inability to define the risks precisely.
3.2 Charge Question 2: Model Inputs
Are the methods used to estimate emission rates, and the method
used to estimate species at the stack appropriate and clearly
described?
3.2.1 Inhalation Screening
The fundamental equations used by the Agency to estimate the
specific inorganic and organic hazardous air pollutant (HAP) emission
rates for process and process fugitive emissions are described by
Equations 1 and 2, respectively. These equations provide a technically
sound methodology for estimating specific HAP emission rates based on
the metal HAP and hydrocarbon emissions data provided in the Background
Information Document (BID) (USEPA, 1994). Although the Subcommittee can
support the Agency's initial decision to employ the AP-42 based
fugitive HAP emissions estimates in the inhalation screening study, the
combined effect of using these conservative data with a conservative
air pollution concentration model has clearly resulted in an
overestimation of ambient HAP air concentrations. On the other hand,
``upset'' conditions were not assessed with any data in this
assessment, and considerable lead may be emitted from these facilities
under such circumstances. This could lead to an underestimation of
ambient HAP air concentrations. To ensure that the use of SCREEN3 will
result in realistic predictions of ambient air pollutant
concentrations, the Agency should evaluate the underlying assumptions
adopted in the area source emissions algorithm, as well as the quality
of emissions data, to determine if they warrant further refinement.
Although the Agency should be commended for its creative and
resourceful use of existing data to estimate specific HAP emission
rates, the Subcommittee identified several opportunities for the Agency
to improve its general description and use of the reported data sets.
First, the Agency should provide a better and more complete description
of the data elements contained in Tables B.1.1 and B.1.2. A reviewer of
these tables would find it difficult to discern what statistical
measurement is actually being reported; i.e., mean, median, or upper
confidence limit (UCL). Second, the Agency should explore using means
as inputs to the HAPs emission rate estimate methodology, since the
means of these likely skewed distributions would provide a quick
screening tool that is more conservative than the median and less
conservative than the 95th percentile upper confidence limit (UCL). The
concern is that simply using of the 95th percentile UCL would screen
out very few, if any, sources. Countering this concern, of course, is
the unknown impact of upset conditions, as noted above, whose analysis
also needs attention. Finally, to provide a reviewer of the methodology
an opportunity to reproduce any or all of the emission rate estimates,
the Subcommittee recommends that the Agency provide an example within
the document that illustrates the proper use of Equations 1 and 2.
As noted in the response to Charge Question 7 below, the
Subcommittee found that the analysis of uncertainty and variability was
incomplete in several respects, thereby depriving the risk manager of
important information when making these important decisions.
3.2.2 Multipathway Risk Assessment
To estimate the specific HAP emission rates from both the process
and process fugitive emission sources, the Agency employed site-
specific HAP emissions information from facility compliance reports, as
well as information from the BID data base, where necessary, in the
multipathway risk assessment. Although the Subcommittee commends the
Agency for demonstrating resourcefulness in employing the best
available site-specific data to generate HAP emission rates, there is
concern over the general approach used by the Agency in employing
secondary data to estimate site-specific HAP emission rates in the
multipathway risk assessment.
To improve the scientific defensibility of both the stack and
fugitive HAP emission estimates for the multipathway risk assessment,
the Subcommittee developed several recommendations for consideration by
the Agency. First, prior to using secondary data for site-specific
emission estimates, the Agency needs to evaluate the quality of the
individual data sets using a clear, easy-to-follow, and well-documented
methodology. Development and implementation of a technically sound data
quality evaluation methodology will provide the Agency with a framework
for establishing the minimum data quality criteria for use in residual
risk estimates. Second, to leverage limited time and resources, the
Agency should collaborate with its industrial partners to identify and
collect additional site-specific monitoring data for use in estimating
process and process fugitive HAP emission rates. Third, because of its
relative importance in characterizing human health and ecological risk,
existing air monitoring data, where available, should be employed by
the Agency for the groundtruthing of site-specific fugitive HAP
emission estimates. Information on the frequency and extent of non-
routine, or upset, conditions must be considered. Finally, to assist a
reviewer in reproducing any or all of the final risk assessment
numbers, the Agency should present a detailed example illustrating the
basic process by which a data element contained in a NESHAP secondary
lead smelter compliance report is used to generate final human health
and ecological risk estimates.
3.3 Charge Question 3: Models
Does the risk assessment use appropriate currently available
dispersion models both at the screening level and at the more refined
level of analysis? Are the models applied correctly? Given the State of
the science, does the risk assessment use an appropriate multi-pathway
model? The assessment uses the IEM-2M model, with some modifications.
Is the IEM-2M model appropriate for use in this regulatory context?
With regard to the modification and application of the model, did the
EPA appropriately modify the model for use in this risk assessment, and
did the Agency apply the model correctly? Is there another model or
another approach that is available at this time that EPA should
consider?
3.3.1 Does the risk assessment use appropriate currently
available dispersion models both at the screening
level and at the more refined level of analysis?
Both the SCREEN3 and Industrial Source Complex Short Term 3
(ISCST3) models have become widely accepted tools-of-the-trade and
probably are the most suited for this point source category. However,
there are minor shortcomings in the models that need to be clearly
articulated. The conservative screening nature of SCREEN3 is designed
to ``capture'' all facilities that may need further investigation. As a
result, the output should result in many false positives which may
reduce the credibility of the model.
In the current assessment, the Agency uses the IEM-2M model for its
multipathway analysis. Although it is the only multipathway modeling
tool that the Agency has readily available for use, there are a number
of concerns regarding the model that are discussed elsewhere in this
Advisory. In the meantime, it should be noted that OAQPS is in the
process of developing the Total Risk Integrated Model (TRIM) as a
flexible, state-of-the-art model for evaluating multimedia chemical
fate, transport, and risk of HAPs. A recent review of this effort by
SAB's Environmental Models Subcommittee found TRIM to be promising and
innovative, while providing a number of recommendations for further
improvement (SAB, 2000). When TRIM becomes available, it should provide
an improvement over the modeling framework used in the current report.
While understanding the need for the Agency to move ahead with the
Residual Risk Program, the Subcommittee is concerned that the IEM-2M
model, as currently employed, is not able to provide the level of
technical information that is needed for making scientifically sound
regulatory decisions. Conceptually, the TRIM model is a significant
improvement over IEM-2M. However, TRIM faces development challenges of
its own that will require resources to address. Therefore, the Agency
faces the difficult near-term choice of trying to improve an inferior
model or committing to complete a superior model. The Agency needs to
develop a plan for how and when they will use these models and how they
will effect a transition from one to the other.
3.3.2 Are the models applied correctly?
A number of assumptions in model execution can affect the outputs.
For example, it was assumed that all emissions come from the center of
the facility, when, in fact, the exact location of emission source--
currently unknown--should have a strong influence on predicted downwind
exposure levels. Locations of stacks in relation to buildings and
building sizes can also result in an incorrect estimation of exposure
rate. Also, using meteorological data from the nearest reporting
meteorological station is an approximation commonly employed. However,
risk assessors and risk managers need to be aware of the suitability of
this approximation in some locales, such as those with complex terrain
and/or long distances between the facilities and the station.
A major issue which must be addressed is how to consider historical
lead and other persistent chemical contamination at the site which was
deposited prior to the promulgation of the MACT standard but which may
nonetheless substantially contribute to on-going exposures post-MACT. A
residual risk analysis that does not add exposures to baseline
contamination to the estimates of on-going contamination may vastly
underestimate the hazard quotient at the site and incorrectly conclude
that the on-going releases pose risks at less than threshold levels.
The Agency chose four cases with relatively high projected risks as
illustrative examples, including both urban and rural settings. The
Subcommittee understands that the terrain in each of these four cases
was unremarkable, and, consequently, it was reasonable to model them in
that way. In the final residual risk assessment for this source
category, all of the facilities in the category will be modeled
individually, and complex terrain, downwash, and other model
adjustments will need to be incorporated into that analysis, as
appropriate.
Other issues raise questions that should be addressed in subsequent
reports. For instance, classification of metals as persistent,
bioaccumulative toxicants (PBTs) is problematic, since their
environmental fate and transport cannot be adequately described using
models for organic contaminants. Also, hazard indices for the ingestion
pathway were developed separately from those for inhalation, and the
impact of this strategy on the non-cancer results is unknown.
3.3.3 Given the state of the science, does the risk
assessment use an appropriate multipathway model?
The assessment uses the IEM-2M model with some
modifications. Is the IEM-2M appropriate for use in
this regulatory context?
The IEM-2M modeling was performed as a set of linked Excel
spreadsheets. Although pertinent equations were given in Appendices,
the implementation of the modeling effort needs to be carefully
examined. The spreadsheets were not provided to the Subcommittee in
time for substantive review by the members, and implementation of
complex spreadsheet models can often lead to unsuspected errors.
Therefore, the Subcommittee was unable to verify the figures and can
only encourage the Agency to carefully examine the quality control
applied in the construction of the spreadsheets. Further, the
spreadsheets should be available to the public.
The Subcommittee understands that use of the IEM-2M model for the
case of mercury (Hg) has benefited from some limited peer review.
However, adaptation of the model to address HAPs other than Hg does not
appear to have been rigorously evaluated (Rimer, 2000). In view of the
unique environmental chemistry of mercury, extrapolation of the model
to other metals must be made with extreme caution.
Through application of the model to a number of source categories
and a number of pollutants with different behaviors, the Agency will
have the opportunity to evaluate the model, at least in part. While
human exposure data are rare, data on environmental concentrations of
pollutants in various media are more widely available. In many cases,
simply knowing that the model estimates are within an order of
magnitude of measured environmental concentrations would provide much
greater confidence in the model as an analytic tool. In particular, it
would be important for the Agency to show that the multipathway model
produces approximately correct estimates results for the concentrations
in food of dioxins/furans and mercury, two important and difficult to
model pollutants. If the evaluation exercises indicate that the model
is at variance with reality, the model will have to be revised and
previous results may need to be recalculated.
At the same time, the Subcommittee recognizes that the Agency is
moving toward final development and implementation of the TRIM computer
model, which would replace the IEM-2M model. Therefore, the Agency will
have to balance the competing needs of making significant improvements
to the old model vs. completing development and evaluation of the next
generation model.
In its present form, the model can be used to show that there may
be a relationship between atmospherically deposited HAP and the total
burden of the particular contaminant in a target ecosystem. It cannot
reliably quantify the amount of deposited HAP expected to be
transferred to the human food chain. While some of the problem could
arguably be related to an overestimate of fugitive emissions, it is
clear that missing process considerations in the model severely limit
its ability to simulate the movement of materials in the environment.
For example, the transfer coefficients have been estimated without
considering the effects of biogeochemical processes on contaminant
reaction rates, speciation, and bioavailability. By ignoring the
physical and chemical drivers, the IEM-2M model may have yielded
grossly unrealistic concentrations of some contaminants in
environmental contaminants. Table 6.8 (p. 160, Vol. I) provides an
excellent example of the model inadequacy. The calculated
concentrations of lead in surface water near a secondary lead smelter
is reported as 103 to 106 g/L, which is a high enough
concentration of lead to sterilize the water. These unrealistic
estimates should be identified as such, and appropriate adjustments
made. In real life, most of the deposited lead would be adsorbed onto
particulates and removed to the sediment. This scavenging removal could
readily reduce the dissolved lead concentration to the measured value
of 0.002-2.0 g/L. Exaggerated concentrations, as well as
unrealistic risks that have been reported for other contaminants, might
likewise be traced to model deficiencies. This is an example of how the
results of the model can be compared with what can be reasonably
assumed about the functioning of a water system. The consequence of
this comparison should be a reevaluation of the results so that the
estimated concentrations are brought into line with what would be
reasonably observed in real ecosystems. A simple re-scaling of the
fugitive emissions estimates, alone, is not likely to solve some of
these obvious problems.
The IEM-2M has a number of limitations of which the decisionmakers
need to be aware. The model does not differentiate between natural and
anthropogenic fractions of a contaminant in a given environmental
medium. It estimates the incremental levels/effects without considering
the levels/effects of the contaminant that have already been built up
in the environmental medium. The Subcommittee suggests that the Agency
discuss how inclusion of baseline concentrations (that is,
contributions from natural plus anthropogenic sources other than the
post-MACT facility) would affect estimated total and attributable
risks. The model does not insure mass balance, nor does it account for
feedback mechanisms between environmental media. While the IEM-2M can
be used to estimate individual excess risk, it is not at all clear from
the documentation that it can provide the spatial and temporal
distributions of exposure that will be needed to provide the link to
distributed populations. Therefore, additional refinement made be
needed so that the model can be used to estimate the population risk.
Uncertainty analysis, a critical adjunct to risk analysis, is not
included in the IEM-2M model. In view of the uncertainties and
assumptions in the model, ground-truthing should be an essential aspect
of the model analysis.
3.3.4 With regard to the modification and application of
the model, did the EPA appropriately modify the
model for use in this risk assessment, and did the
Agency apply the model correctly?
The IEM-2M model should be regarded, at best, as a work-in-
progress. The Subcommittee understands that the IEM-2M will be replaced
by the TRIM model, referenced above, once the latter has been
sufficiently well-developed. In the meantime, in light of the
limitations noted about the IEM-2M, its results must be regarded with
informed caution.
3.4 Charge Question 4: Choice of Receptors
The Agency identifies the home gardener as the appropriate receptor
to estimate risks to the residential population and the farmer to
embody high end risks. Are these receptors appropriate for this task?
The home gardener and the farmer are acceptable receptors for this
task, but their assumed exposure scenarios need to be modified in order
to provide a more realistic estimate of the risks to typical members of
the local community. Specifically, the input assumptions for both
scenarios may be unrealistically high compared to the real exposures of
the local residential and farm communities, particularly regarding
inhalation and food preparation activities. The inhalation exposures
assume that the receptor is exposed to outdoor concentrations 24 hours
per day. The food ingestion pathway assumes that home-grown produce is
not washed. The risk model results are very sensitive to these
assumptions. Moreover, these exposure assumptions make it especially
difficult to check the model results through comparison with data.
Existing and potential data on human exposure levels are likely to be
from people in nearby communities who do not have these high-end
exposure behaviors. For these reasons, the Subcommittee recommends that
the Agency also model the exposure of home gardeners who are not
outside all the time and who do wash their home-grown produce.
Further, the case study assumes continuous exposure over a lifetime
for inhaled HAPs but exposure over shorter periods for ingestion of
soil, water, and produce containing HAPs; i.e., 12 years for a home
gardener and 17 years for a farmer. The reason for this apparent
inconsistency should be made clear.
The overall characterization of the risks to the local community
needs to be clarified when the population exposure assessment is
completed.
3.5 Charge Question 5: Ecological Risk Assessment
Given currently available methods, are the models used for the
ecological assessment appropriate? Are they applied correctly? Are the
ecological benchmarks appropriate?
3.5.1 General Statement
In the previous SAB review of the residual risk issue (SAB, 1998b),
the Subcommittee strongly encouraged the Agency to elevate the
prominence of ecological risk and to establish a commitment to
ecological concern that was more nearly co-equal to that of human
health. The recommendation was driven by the neglect of ecological and
natural resources considerations in the draft Report to Congress
(USEPA, 1999).
At the March 1 briefing, the Agency stated that the risk to
ecological and natural resources will not be addressed at this time in
other than a screening level analysis; i.e., a hazard assessment,
rather than a risk assessment. This position is unfortunate, even for a
document that is admittedly a work-in-progress, since this shortcoming
was strongly identified in the Board's earlier report (SAB, 1998). Such
a position would be unacceptable in the final document in that it would
ignore the legal mandate to avoid ``an adverse environmental impact''
that is ``significant'' and ``widespread'' and likely to result in the
``degradation of environmental quality over broad areas'' (CAAA Section
112(a)(7)). By pursuing a hazard assessment for secondary lead smelters
rather than a risk assessment, the Agency will likely generate a large
number of ``false positives'' that will make the task of the risk
manager more difficult. It could also have the unwarranted effect of
setting a precedent for using hazard assessment for ecological and
natural resources analysis in lieu of a risk assessment for future
residual risk analyses.
3.5.2 Given currently available methods, are they for the
ecological assessment appropriate?
As a matter of first importance, the document should indicate
whether the ecological risk assessment presented here is being
developed in accordance with the Agency's Ecological Risk Assessment
Guidelines (EPA, 1998). These guidelines have been developed over
several years, have involved many experts from the ecological science
community, and have been endorsed by the SAB (SAB, 1997).
The ecological risk screen is underpinned by five concatenated
models, with the term ``model'' used loosely to include both formally
constructed code, as well as more simple spreadsheets. The source,
dispersion, deposition, and multipathway models are the same as those
used to conduct the human health characterization. The fifth and last
model--and the one unique to ecology and natural resources--is the
spreadsheet to screen for ecological effects using the Hazard Quotient
(HQ) and Hazard Index (HI) methodologies. The only two models that are
specifically relevant to ecology and natural resources are the
multipathway and ecological effects models.
(a) Multipathway Models.--The multipathway model is appropriate for
the task of characterization of exposure and supporting a risk
assessment. The model has the necessary features to handle the
transport, transformation, and fate of organic and inorganic compounds
in multiple media; i.e., soil, water, air and biota. In light of the
results from both human health and ecology analyses, the ``screened
risks'' appear to result from a few critical parts of the code, most
notably soil-to-plant uptake, atmosphere-to-plant deposition and
accumulation, bioaccumulation in the food chain, and transport in
aquatic environments. Because these processes are so instrumental in
the overall risk analysis and because the model's validity was
repeatedly questioned, it is recommended that these critical subcodes
be peer-reviewed to assure that the mathematical formulation is
reasonable, current, and scientifically defensible. However, as noted
above in Section 3.3.3, the Agency needs to balance efforts to improve
the IEM-2M model against the need to develop and implement the next
generation models, such as TRIM.
Although multipathway methods are more than adequate for the task
of screening and are certainly the appropriate method for a risk
assessment, it is not necessary to use multipathway models in the
initial screening assessment. Traditionally, multipathway models are
reserved for those compounds that are persistent and bioaccumulative
toxicants (PBTs). Unless the entire list of HAPs is made up of PBT
chemicals, it would be more efficient to screen using simple fate and
direct exposure models. If a PBT compound were to pass the toxicity
screen (HQ<1.0), the hazard of direct contact would likely be
insignificant, and the Agency could decide if the compound warrants a
review of higher trophic considerations based on size and spatial
distribution of the industry source category, plus the dispersion
potential of the HAP. If the sources were many, large, and widely
distributed, it might pass the test of being ``widespread'' and likely
to result in ``degradation in environmental quality over broad areas''.
Otherwise, only compounds with HQ>1.0 would be the subject of the
multipathway analysis.
(b) Ecological Risk Screening (i.e., Hazard Model.--The Agency
provides a rudimentary hazard ranking or screening process for culling
through the HAPs associated with secondary lead smelters source
category. The method is based on the
generation of Hazard Quotients (HQs) which are simple ratios of
environmental concentrations to effects-based environmental benchmarks.
The benchmark is a concentration level in a medium at which little or
no potential exists for an hazard. As a screening tool, this approach
is valid, although it necessarily results in a high number of ``false
positives''. Screening ecological hazards with this approach is well-
established for use in ranking and prioritizing hazards associated with
chemicals; e.g., new product design and approval, risk-based corrective
actions at contaminated sites, and prioritization of resources in
regulatory programs.
As is well-stated in the case study, this conservative methodology
is only used either to remove chemicals from further risk management
consideration (i.e., the risk is acceptable) or to indicate that there
is a need for further analysis. The HQ approach with such conservative
effects benchmarks is really aimed at protecting all individuals in the
ecosystem and, by inference, to protecting the structure and function
of the ecosystem in which that individual lives.
3.5.3 Are they (the models) applied correctly
Given that this analysis is a screening exercise (i.e., hazard
assessment) and not a risk assessment, the models are applied
correctly, with the exception of the summation of HQs, as discussed
below. There are several key aspects of the application for a screening
exercise that warrant the Agency's attention:
(a) Top Carnivores.--This functional group is omitted from the
model in terrestrial ecosystems; yet it is likely to be the most
responsive functional group for PBTs. The rationale for not including
this functional group (i.e., ``Data are not available'') is contrary to
what can be done in a screening exercise.
(b) Background Concentration.--For ecological systems, the
inclusion of geochemical background concentrations is more important
than for human health, particularly for those chemicals that have a
natural source; e.g., manganese, mercury, and nickel. The natural
background issue should be re-evaluated in order to address the risk to
ecological and natural resources.
(c) Summation of HQs.--Generating an HI by summation of HQs for
chemicals in different classes (e.g., metals and organics) or for
obviously different organics (e.g. phthalates and PAHs) goes beyond
current good practice in screening ecological risks. The resulting HI
is possibly misleading. Summation of HQs should be limited to chemicals
that operate via the same mode of action on the same target organ or
system.
3.5.4. Are the ecological benchmarks appropriate?
It is not possible to completely answer this question from the
information given. The selected benchmarks represent the current State
of the practice for screening assessments, many of which have been
developed for use at contaminated sites as a means of focusing
management action on only the chemicals of greatest concern. For some
of these situations, especially those involving water and sediment,
there may be different benchmarks for freshwater and marine systems,
and it is not clear which was used in this case.
What is clear is that these numbers should not be used in a
sophisticated risk assessment. The data behind these criteria may
support a risk assessment, but the final ``criteria value'' can only be
used to eliminate chemicals of concern. As HQs are refined, the
exposure estimate should be refined to reflect site-specific
conditions, and the characterization of effects should also advance
from a general benchmark to an estimate of a toxic threshold, based on
dose-response data for a representative or surrogate species.
3.6 Charge Question 6: Health Risk Assessment
Section 3.4.1 of the Report to Congress identifies several data
sources that the Agency would draw upon for choosing dose-response
assessments to be used in residual risk assessments. The Report also
states that EPA will develop a hierarchy for using such sources. Given
available dose-response information, is the hierarchy presented in this
assessment appropriate (see especially footnote #6, section 2.2.1)? For
each chemical included in the assessment, is the choice of dose-
response assessment appropriate? Are the dose-response assessments
appropriately incorporated into the assessment?
The Agency has used a reasonable approach to summarize the toxic
effects and the dose-response values for the HAPs included in the
multipathway analysis. The document succinctly summarizes a tremendous
body of information and accurately describes the endpoints upon which
reference doses are derived. The important information related to each
is adequately summarized.
The toxic effects and dose-response analysis information are
derived from multiple sources according to the following hierarchical
structure: Integrated Risk Information System (IRIS), Agency for Toxic
Substances and Disease Registry (ATSDR) toxicology profiles, Health
Effects Assessment Summary Tables (HEAST) and State of California
Environmental Protection Agency (CalEPA) values. However, the document
does not provide the rationale for the specific ranking. The
clarification provided at the March 1 meeting should be a part of the
document, including the intent to make chemical-by-chemical decisions
about which data base to use and the often higher quality of
information in the CalEPA data base (CalEPA, 19 . . .) than is found in
the older HEAST compendium (USEPA, 1994).
The residual risk exercise emphasizes, once again, the importance
of having accurate, current information in the Agency's IRIS data base.
As it has been stated in the past (NRC, 1994; USEPA, 1999), the SAB
continues to encourage the Agency to create and maintain a credible set
of data in IRIS. Another SAB panel will review a Congressional-directed
study of IRIS later this year.
While the case study has employed methods that are routinely used
at the Agency, the Subcommittee has some concerns. The approach appears
to utilize the default assumption that all health effects described are
of comparable severity and concern. For example, risk estimates derived
for some of the HAPs compounds are based on rather vague endpoints,
such as body weight loss, which are not explicitly associated with any
disease process; whereas, in other cases, the assessment may center on
effects, such as pulmonary or neurotoxicological effects, that are of a
more grave character. This approach is another example of the
conservative stance taken through much of the analysis. However, the
risk assessor and the risk manager need to recognize and appreciate
these differences in potential severity of health effects when
comparing and combining the results of the analysis.
Another supposition which may ultimately prove problematic is the
assumption that effects of mixed exposures are additive. In reality,
mixtures may produce effects that are additive, synergistic
(potentiated), or even attenuated. The current default assumption is
necessitated by the absence of any information with which to more
precisely model such effects and, therefore, represents a conservative
approach.
A related point is the difference in confidence with respect to
cancer potencies calculated from human vs. experimental animal data.
Unit risk estimates based on human data are generally maximum
likelihood estimates calculated from studies that, if anything, have
biases toward underestimating human incidence of carcinogenicity
because they are usually based on worker populations, not children, who
are arguably more susceptible. Exposure estimates in this case usually
have substantial uncertainties that tend to bias comparisons of more
vs. less exposed workers toward the null and, therefore, toward lower
estimates. On the other hand, animal-based unit risk estimates include
a number of procedural assumptions that are thought to usually lead to
overestimates of risk, such as the use of 95 percent confidence limits,
choice of the most sensitive species for projection to humans, etc.
The Subcommittee is concerned about the potential problems
associated with a residual risk assessment that must omit HAPs in
assessments of the risk of noncancer endpoints due to the fact that
there are no dose-response data on these compounds currently available
and that Agency policy dictates against using probabilistic values. For
example, in the case of secondary lead smelters dioxins/furans are
omitted from consideration as a non-cancer risk due to the lack of
data. While the Agency indicated at the March 1 meeting that dioxins/
furans would be included in the next iteration of the process, other
compounds are, and presumably would continue to be, omitted due to the
lack of data. The document needs to address this limitation directly
and indicate how the decisionmaking process will take these
vulnerabilities into account. As one possible way to address the
problem, the Subcommittee recommends that the Agency explore the use of
quantitative structure-activity relationships (QSAR) to assess whether
any of the organic HAPs with insufficient dose-response information
might, in fact, be a significant concern that is currently being
overlooked. While QSAR would not play a definitive role in the
analysis, it could identify potential problem compounds that are
otherwise ignored entirely in the current case study.
The Subcommittee understands that the Residual Risk Program is
following current Agency guidance by calculating hazard quotients (HQs)
for non-carcinogens, with the implicit assumption of a threshold in the
dose-response curve. However, the HQ approach is not a true risk
assessment (i.e., a probabilistic estimate of the likelihood of harm),
is not based on a biologically compelling foundation, and does not
explicitly address the possibility of low-dose effects above or below
the reference dose (RfD), even for highly non-linear dose-response
relationships. As a part of its overall effort, the Agency should
continue work on developing and implementing a more scientifically
based risk assessment procedure for non-carcinogens that would lead to
improved risk assessments. For example, some reports now suggest that
the slope defining Pb effects is actually steeper at blood lead levels
below 10 g/dL than above it.
As noted above, the Subcommittee is concerned about how some of the
results of this analysis will be treated. In particular, while the
generation of hazard index (HI) values can be useful, despite its
implicit limiting assumptions (e.g., additivity of all effects), there
is no indication in the document of how these values will be used in
the final decisionmaking process. Without some indication of how they
will be used and for what purpose, the Subcommittee is unable to
comment effectively on the appropriateness of HIs in this case.
Also, as discussed above, it is clear that the residual risk
analysis results in an estimate of incremental exposure and, in the
case of cancer, incremental risk of disease. However, it is not clear
how the Agency plans to use the incremental exposure estimates in the
case of non-cancer effects, when these additional exposures (that is,
in addition to already existing exposures from other sources) might
subject some elements of the population to a ``level-of-concern'';
e.g., HI>1.
Two examples are included in the document that relate the derived
HQs to anticipated consequences of human exposures: the cases of lead
and dioxins/furans. The lead case allows some type of human health risk
assessment, since blood lead levels associated with specific human
health effects have been well documented. However, in both cases, the
outcome suggests problems with the models. Specifically, the derived
blood lead values are so high that they would be associated with gross
toxicity; e.g., acute encephalopathy and even mortality. If such
effects are real, it is quite likely that the problem would have
already been discovered by the local medical community. Therefore,
these derived blood lead values are a clear indication that the
multipathway model has problems and needs to be revised.
As noted above, the Agency indicates that some of these problems
may not be problems of the model per se, but rather problems associated
with overestimates of fugitive emissions. While the Subcommittee agrees
that overestimates of fugitive emissions may play a role here, there is
no indication of the extent of that role. On the other hand, it is
quite clear that the model fails to consider biophysical chemical
processes that definitely play an important role and that the model has
not benefited from a rigorous peer review. (The model was not a major
focus of the SAB review of mercury (SAB, 1998a).) In fact, some
consideration should be given to using the TRIM model in its incomplete
version rather than continuing to use IEM-2M. A more integrated and
complete uncertainty and variability analysis would help to clarify
these matters.
Additionally, Table 6.9 compares modeled concentrations of dioxins/
furans in human milk with measured concentrations in human breast milk.
It shows that modeled concentrations are notably lower than those
measured in human milk. These findings are interpreted as indicating
that emissions of dioxins/furans from secondary lead smelters are a
minor contributor to overall dioxins/furans nationwide. An alternative
interpretation (namely, that dioxin is not adequately modeled in the
residual risk assessment paradigm) is not even considered, which
clearly seems to be an oversight.
Finally, at this stage in the development of the assessment, the
Agency has not generated any population risk estimates. The
Subcommittee would like to emphasize the fundamental importance of
generating such estimates in the final document. Currently, there is
little discussion of how this critical step will be taken.
3.7 Charge Question 7: Uncertainty and Variability Assessment
Did the assessment use appropriate currently available methods to
identify the variables and pathways to address the uncertainty and
variability assessment? Are the methods used to quantify variability
and uncertainty acceptable? Are there other, more appropriate methods
available for consideration?
In short, the uncertainty and variability (U&V) assessment is one
of the weakest parts in the draft case study and appears to be a rather
peripheral afterthought to a main analysis, rather than an example in
which U&V considerations are fully integrated into a project. As noted
above, this concern was mentioned prominently in connection with the
multipathway exposure model results.
The fact is that U&V analysis has advanced significantly over the
past 10 years. The combining of traditional point-estimates of
parameters, together with and their separate ranges of uncertainty,
hardly qualifies as even a ``quick-and-dirty'' analysis these days.
Instead, readily available computing power and increased experience
with distributions for various quantities (e.g., EPA Exposure Factors
Handbook (USEPA, 1997) have combined to made distributional analysis of
U&V, even simple Monte-Carlo analysis, much more the standard
expectation for the field. These techniques have by no means reached
the level of being ``cookbook manipulations''. Rather, they do require
skilled, knowledgeable judgments on a case-specific bases. However,
they are being applied with much greater frequency, providing the basis
for much more informed decisions, particularly in significant
decisionmaking contexts, such as the residual risk program under
discussion here (Cullen and Frey, 1999; Thompson, 1999; Hattis and
Froines, 1992; Hattis and Burmaster, 1994; Hattis et al, 1999).
In the first instance, the terms ``uncertainty'' and
``variability'' need to be clearly defined and consistently used.
Variability refers to real differences in things or people that would
be seen even with perfect measurement or estimation techniques; e.g.,
the differences in the body weights of the individuals in an exposed
population around a lead smelter. Uncertainty, by contrast, refers to
the imperfection in our knowledge of the values of a specific
parameter; e.g., characteristics of the throughput of material at a
particular lead smelter. Generally, uncertainty can be reduced by
gathering better information, but real variability will be unchanged,
although it can be better characterized by better information.
The failure to distinguish variability from uncertainty in the
present analysis almost guarantees confusion. Variability and
uncertainty are different things and require different techniques for
estimation. For example, soil type may vary from facility to facility,
but it may be relatively uniform at any one facility. If the soil type
is not known at a particular facility, the distribution that describes
variability among facilities where soil type is known can be used to
construct an uncertainty distribution for the particular facility.
Without understanding the distinction between uncertainty and
variability, a risk manager cannot make a fully informed decision based
on the results of the U&V analysis. A properly prepared analysis of
uncertainty and variability analysis should help a risk manager to
answer the question, ``What actions must I take in order to assure that
no more than Y percent of the population exposed incurs a risk greater
than X, with confidence Z?'' In other words, the risk manager should be
able to understand not only how risk might vary from person to person,
as described by X and Y, but also how sure we are about our estimates,
as described by Z (cf., Hattis and Anderson (1999), and Hattis and
Minkowitz (1996)). That kind of goal for the U&V analysis is not made
explicit in the Agency's case study.
Although it is challenging to carry out an analysis that fully
separates considerations of uncertainty and variability, and although
it is sometimes a matter of perspective whether a given distribution
describes uncertainty or variability, the Subcommittee did not find the
Agency's justification for combining the two in its analysis
convincing. For example, consumption rates of water and food really do
vary from person to person, and the corresponding calculated risks due
to any specific smelter's emissions would also vary accordingly. On the
other hand, the distribution used for the annual average emissions of
the smelter is dominated by uncertainty, since so few data are
available from post-MACT facilities. However, there is little
expectation that annual average emissions (in g/sec) would vary
substantially from year to year.
The Agency chose to use distributions for emissions and for some
elements of the exposure analysis, but not for the parameters of the
fate and transport models or of the toxicity analysis. While the
Subcommittee understands that it is currently Agency policy not to
undertake distributional analyses of toxicity information, the Agency
should reconsider this policy. Some members of the Subcommittee believe
that omitting the uncertainties in the toxicity data from the
assessment vitiate much of the benefit of performing the U&V analysis,
and that the literature does contain early illustrative efforts to
estimate uncertainty and variability for risks of both cancer and non-
cancer endpoints (Hattis et al. (1999); Hattis and Barlow (1996);
Crouch (1996)). Moreover, omitting any distributional treatment of the
transport and fate module makes any conclusions from the U&V analysis
suspect. Although the Subcommittee agrees that iterative calculations
using the full ISCST-3 and IEM-2M models would be computationally
intractable, it does not seem unreasonable to introduce some overall
uncertainty distribution to represent the uncertainties in risk
introduced by all of the assumptions and parameter choices embedded in
those models. The governing notion is that the while distributions
based on data are certainly preferred, the use of subjective
distributions--fairly (unbiased) developed, technically rationalized,
and clearly presented--can provide useful and valuable insights that
can credibly inform the decisionmaking process.
In this case, the Subcommittee also found that the description of
how some of the distributions were derived to be incomplete, even for
the parameters that were included in the analysis. Although in many
cases the Agency simply took distributions that had already been
described for other Agency purposes (e.g., the Exposure Factors
Handbook (USEPA, 1997)), in others it seemed to arrive at a
distribution with very little evident rationale. For example, the
document states, ``we assumed that annual lead emissions follow a log-
normal distribution, with the emission rate falling within two orders
of magnitude of the value given in the compliance report 95 percent of
the time'' (later corrected to 99 percent of the time). Although the
document is far from clear on this point, in oral presentations EPA
representatives indicated that this assumption was based on some
analysis of emissions observations by a knowledgeable contractor, Dr.
Christopher Frey--which was useful, reassuring information. In the next
iteration of the document, this analysis should be presented in detail
and, to the degree possible, the analysts should consider the need for
adjustments in observed emissions data across plants to account for
differences in throughput characteristics, among other relevant
factors. To the degree that day-to-day and/or plant-to-plant variations
in emissions can be explained on the basis of factors such as
throughput, the estimate of uncertainty in annual average emissions may
be reduced.
Another major problem is that the current analysis does not follow
existing EPA guidance on the documentation and presentation of
distributional analysis (USEPA, 1997). Specifically, that guidance
emphasizes that the model itself and derivations of distributions used
in the analysis must be transparently presented in sufficient detail
that a reviewer can reproduce them. Therefore, the case study itself
should have included, as an appendix, both the extensive display of
results for each stack, as well as the spreadsheet model equations and
the mathematical form of the distributional assumptions that were used.
The Subcommittee believes that any report of the results of a U&V model
must include documentation of the model spreadsheet itself, the
dependencies among parameters that are or (in the case of independence
assumptions) are not built into the model, and the precise mathematical
form of the distributional assumptions. For example, from the current
presentation it is not clear if correlations have been built into the
emissions of lead and other HAPs from different stacks that might
reflect different processing rates on different days, or whether these
are considered as independent.
Finally, the Agency's treatment of ``upset conditions'' is not
clear. While there is a description of the assumptions made to account
for such occurrences, the explanation/justification of the assumptions
is lacking. Since emissions associated with upset conditions can, in
some cases, outweigh the impact of emissions during normal operation,
it is especially important that this situation be directly addressed
and clearly explained.
In summary, the Subcommittee was unconvinced by the rationale for
the selection of variables and pathways to address in the U&V
assessment and found the methods for quantifying the U&V suspect in at
least some respects. The Subcommittee recommends that the Agency redo
the analysis starting with a clearly stated management objective,
incorporating a better degree of separation of variability from
uncertainty, and generating a more comprehensive treatment of the most
important sources of uncertainty and variability.
3.8 Charge Question 8: Presentation of Results
Does the Agency's document clearly present and interpret the risk
results? Does it provide the appropriate level of information? Do the
figures and tables adequately present the data? Do the formats provide
for a clear understanding of the material?
This Charge Question addresses the important issues of (a) risk
characterization, which goes beyond numerical presentations of results
to qualifications and discussions of uncertainty and data limitations
(USEPA, 1999, p. 70), and (b) risk communication, which conveys those
results in easily accessible terms to interested and affected parties.
The focus of the discussion here is on the presentation of the results.
The majority of Subcommittee views on the various aspects of the
results themselves are found in response to the earlier Charge
Questions.
3.8.1 Initial Screening Analysis
According to EPA, the screening analysis is designed to obtain
preliminary inhalation risk estimates for the 23 facilities and 50
HAPs. In the course of the analysis, many other simplifications and
conservative assumptions are made, such as generic assumptions about
releases of HAPs from smelter facilities. The default release
characteristics used in the SCREEN3 modeling are clearly presented in
Table 2.2. The Agency has indicated that all of the assumptions used in
the initial screening analysis are not conservative and that best
estimates (simplifying defaults) are used. A sensitivity analysis or
other qualitative discussion of the effect of these selections on the
results should be included in order to give the reader a better
appreciation of the robustness and the conservativeness of the initial
screening analysis.
In some cases, the report identifies areas in which information was
not available, e.g., housekeeping procedures for fugitive emissions.
During the Agency presentation at the meeting, four possible approaches
to estimating fugitive emissions were presented: back calculating from
lead monitoring data, theoretical modeling, extrapolating from another
source that has conducted fugitive emission testing, and direct
measurement. These approaches should be identified in the report, along
with general methods for dealing with missing data, to help the reader
understand what would be required to gather this information.
The discussion of the screening (Section 2.2.4) portrays easily
readable risk results for each HAP for cancer/non-cancer risk. It
presents maximum and minimum risk values for each individual organic
and metal HAP. The table should include an explanation of the maximum
and minimum values; i.e., they are simply the range of estimates
determined for all of the facilities.The text discussion clearly
indicates the bottom line (risks above one-in-a-million) and the fact
that some of the HAPs are associated with higher values. Procedures for
arriving at the risk estimates and identifying where overestimates
occurred are clearly presented.
Uncertainty estimates are not presented in the tables, nor are they
discussed in this section. This should be explained in the results
section. The text should expand on the potential impact of the
discussion in footnote 8 concerning the lack of dose-response values
for the ten HAPs that have not been considered in the case study due to
a lack of available dose-response information.
The form in which numbers are presented in Tables 2.3 and 2.4
(i.e., as exponents) is not easily communicated to the public, and
perhaps an alternative means should be considered. The Agency should
keep this form for the Tables, but should consider using consistent
cancer risk expressions in the narrative of the case study, avoiding
the use of different expressions for cancer risk. For example, the use
of the expression 8-in-10,000 should be changed to 800-in-a-million.
This will allow the lay reader to place the results into the common
context of the less than one-in-a-million expression which appears in
the CAAA and throughout the case study.
Section 2.2.4.2 identifies a large set of defaults and assumptions,
without providing an explanation or rationale. More discussion of these
defaults and assumptions is warranted, including statements about how
they affect the final result. If the effects of the assumptions are
unknown (as identified in this section), some discussion of why this is
the case should be included.
The conclusion section for the initial inhalation screening
analysis (parts of Section 2.2.4.3), are troublesome because of their
lack of specificity with respect to the chemicals being discussed and
the sources. For example, in the statement ``Metal HAP risk results
exceed these levels'', the identity of the metal HAP is unclear.
Furthermore, any conclusions for this section are questionable since,
as is pointed out in the report, the largest source is fugitive dust
emissions which are very uncertain due to uncertainties in emission
rates and the failure of the estimates to agree with NAAQS measurements
made in the vicinity of these facilities.
Section 2.4 (Overall Summary of the Initial Screening Analysis) is
very brief and would benefit from a description of the organization of
the initial screening analysis and how it leads to the multipathway
screening analysis. The selection of facilities for the refined
analysis needs to be placed into some type of risk management
framework. These facilities were obviously selected since they
represented the highest risk (e.g. cancer risk > 9000-in-a-million and
HQ>70). However, a defined process is needed for selecting which
facilities will be included in the refined analysis. For example, if
the 100-in-a-million cancer risk value were used only two of the 23
facilities would pass the screening criteria. The use of this cancer
risk range would be consistent with the benzene decision and the
Commission of Risk Assessment and Risk Management (CRARM)
recommendations by having the total cancer risk from the facility being
in the range of less than one to one hundred in a million for the
screening assessment. In addition, if a hazard quotient of 10 is used
as an action level for the screening assessment, as recommended by
CRARM, then a decision to eliminate facilities 6, 9, 12, 20, 25 and 29
for further analysis of noncancer health effects can be made. A section
entitled 2.X Initial Screening Analysis: Selection of Facilities for
Refined Multipathway Analysis should be added in the Chapter 2 results
section in order to present this rationale more clearly.
Section 2 needs to provide a better description of the 23
facilities that have undergone the initial screening analysis. This
information would include a general physical description of the
facility size, location (urban, suburban, rural or industrial) and
terrain, the annual amount of material throughput, the degree of
facility enclosures (total or partial enclosure of fugitive sources),
and, perhaps most importantly, the current HAP emission inventories for
these facilities. The inventory information could be obtained from the
1996 or more current National Air Toxics Assessment (NATA) project that
the Agency is working on or HAP emission statements filed with State
environmental agencies. Some of this information is readily available
from the ``Locating and Estimating Air Emissions from Sources of Lead
and Lead Compounds'' (USEPA, 1998). This information would be very
useful for the risk manager when evaluating the initial screen inputs
and results and would serve as a check on those facilities which would
be selected for further refined analysis. The brief discussion
contained in the case study is inadequate.
3.8.2 Multipathway Analysis
Section 3.3 (Results and Key Issues of the Multipathway Analysis),
is much too long for a results and issues section. The heart of this
material is on pp. 94-96, so a reorganization of this portion of the
report would be in order.
The Subcommittee found a need for a discussion about a few key
issues, in addition to those already listed in Section 3.3.2.
Specifically, these are the lack of consideration of background
concentrations in the risk analysis and the effects of the adjustment
of the nickel inhalation unit risk estimate which reduces the
conservatism of the cancer risk estimates.
The Report to Congress (USEPA, 1999) discusses the need to include
background risk and the difficulty associated with this specific issue.
The case study does not address background risk issues around any of
the 23 facilities in the human health and ecological risk assessment.
This is serious omission from the case-study, and the Agency should
address this issue at a minimum from a qualitative/quantitative point
of view, well beyond the comparisons made in Chapter 6. The absence of
an assessment of background risk seriously impacts statements about the
conservative nature of the refined screening assessment.
The use of only 25 percent of the inhalation unit risk estimate for
nickel subsulfide needs to be explained in greater detail, since it
will have a large impact on the total cancer risk estimates in the case
study.
Some Subcommittee members thought the tables and figures were clear
and comprehendible; others felt they could be clarified. For example,
the plots and bar charts presented as a part of the Agency's briefing
on March 1 were very helpful and could be added to the document.
HAPs that were not included in non-cancer endpoints should be
clearly identified, together with an explanation of why they were
omitted.
3.8.3 Uncertainty and Variability Analysis
As indicated in Section 3.7 above, the Subcommittee had serious
concerns about the handling of the U&V assessment. The comments below
pertain primarily to the format and presentation, rather than the
adequacy or completeness, of the underlying analysis. In short, the
Subcommittee finds that the presentations (e.g., graphical and tabular
displays) are conceptually sound and effective. However, many of the
procedures used in the assessment are not as well-laid out as they need
to be.
The tables and figures used throughout Section 4 provide a concise
and well-thought out approach for the presentation of variability for
each scenario evaluated. They allow the reader to evaluate the broad
spectrum of risk and the impacts of the various exposure parameters
used in the refined multipathway risk assessment. These tables and
figures significantly enhance the comprehensibility of the variability
assessment results. For example, the use of a 13.3 m3 inhalation rate
in the multipathway analysis (Table 4.3), when cross-referenced with
Table 4.4, indicates that the inhalation value used is between the 25th
and 50th percentile and is really not that much of an extreme
conservative assumption. When the inhalation rate is coupled with the
70-year duration of exposure and the fraction of the day at home, the
final risk estimate falls into the 95 percentile for inhalation risk.
This is consistent with the recommendations contained in the NRC (NRC,
1994) and the CRARM (CRARM, 1997) reports and the language in the 1990
CAAA to estimate risk for ``. . . the individual most exposed to
emissions from a source . . . '' This presentation format allowed the
reader to understand in a rather simplistic manner the amount of
conservatism that was used in the refined multipathway risk analysis
for each exposure parameter. So, if the risk manager wanted to observe
the impact of setting each parameter (maximum inhalation rate, maximum
exposure duration, maximum ingestion rate , maximum time spent
outdoors, etc.) and the impact it has on the risk estimates, it can be
done rather quickly.
The inclusion of the point estimates in Tables 4.5 and 4.6 is an
excellent way to concisely present information to the risk manager. The
use of a large circle to identify the final cancer risk estimates on
the probability figures (Figures 4.2a--4.7b) that would be used by the
Agency to characterize the risk for the final risk management decision
would significantly enhance the presentation of the results and make
them easier to interpret. The tables and figures provide the risk
manager with the ability to view the broad spectrum of risk
predictions, which includes risks to the average exposed individual
(AEI), the maximum individual risk (MIR) and the maximum exposed
individual (MEI).
The use of distributional analysis is unclear. The technique was
used for some steps in the risk assessment, but not all. For example,
the distributional analysis was clearly used for exposure estimates,
because data from the Agency's Exposure Factors Handbook (USEPA, 1997)
were used. However, it is not clear whether the same data source was
used for the emission estimates.
As noted in 4.8.7 above, the selection of variables and methods of
quantifying variability and the distinction between uncertainty and
variability is not clear. Such a discussion should be firmly grounded
in the Agency's risk management goals and a clear understanding of how
these results will be used to help achieve those goals.
3.8.4 Risk Characterization
In Section 5.7 the focus is whether the HQ values are above or
below 1. The Agency should consider the robustness of such ``bright
line'' decisions in light of the uncertainties involved. Section 5.8
was clear and acceptable to the group.
3.8.5 Summary and Discussion
Keeping in mind the limitations and problems identified with the
methodology above, this section presents a good summary of results.
Tables 6.1 and 6.2 provide a good overview summary of the final results
for the refined multipathway risk assessments. The presentation of
results could be greatly enhanced with the addition of more site-
specific information to the case study. The collection of additional
data should not be an overwhelming task. The Agency should consider the
importance of such a refinement before the case study becomes a public
document.
The discussion in Section 6.2.1.1 should be expanded. The pre-
NESHAP monitoring data from New York indicates that the NAAQS for lead
can be exceeded and that the stringent control of fugitives can result
in a dramatic lowering of ambient concentrations of lead and probably
other metal HAPs in the vicinity of secondary lead smelters.
Section 6.2.1.5 needs to be expanded since it provides information
on an excellent biomarker for potential exposure; i.e., blood lead
levels. The inclusion of this type of information would greatly enhance
the case study. The Center for Disease Control and Prevention (CDC) and
State Health Departments should be consulted to find out if there is
any other information on blood lead levels in children who reside in
communities that are in close proximity to secondary lead smelters.
Table 6.7 should be modified by including the distance to the
monitors, as well as a brief discussion of siting issues (e.g.,
predominant downwind or upwind monitoring locations) before any
comparisons are made. The same point can be made for the comparisons of
the surface water concentrations. However, the Agency does
appropriately acknowledge that the comparisons in Table 6.8 are not
meaningful.
In summary, the information in the report is generally well-
presented in some instances and could be significantly improved in
others, as noted above. However, it is important to gather and evaluate
more site-specific information, using the risk assessment tools
presented in the case study, before any final risk management decisions
are made for this source category.
4. references
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``Framework for Environmental Health Risk Management'', Final Report,
Volume 1; ``Risk Assessment and Risk Management in Regulatory Decision-
making'', Final report, Volume 2.
Crouch, E.A.C., 1966, ``Uncertainty distributions for cancer
potency factors: Laboratory animal carcinogenicity bioassays and
interspecies extrapolation.'' Human and Ecological Risk Assessment 2:
103-129.
Cullen, A.C. and Frey, H.C., 1999, ``Probabilistic Techniques in
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Uncertainty in Models and Inputs'', Plenum Press, New York.
Goble, R. and Hattis, D., 1995, ``When the Ceteris Aren't Paribus--
Contrasts between Prediction and Experience in the Implementation of
the OSHA Lead Standard in the Secondary Lead Industry,'' Report to the
Office of Technology Assessment, U.S. Congress, by the Center for
Technology, Environment, and Development, Clark University, July.
Goble, R., Hattis, D., Ballew, M., and Thurston, D., 1983,
``Implementation of the Occupational Lead Exposure Standard,'' Report
to the Office of Technology Assessment, Contract #233-7040.0, MIT
Center for Policy Alternatives, CPA 83-20, October.
Goble, R. and Hattis, D., 1995, ``When the Ceteris Aren't Paribus--
Contrasts between Prediction and Experience in the Implementation of
the OSHA Lead Standard in the Secondary Lead Industry,'' Report to the
Office of Technology Assessment, U.S. Congress, by the Center for
Technology, Environment, and Development, Clark University, July.
Hattis, D., and Anderson, E., 1999, ``What Should Be The
Implications Of Uncertainty, Variability, And Inherent `Biases'/
`Conservatism' For Risk Management Decision Making?'' Risk Analysis,
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Hattis, D., Banati, P., and Goble, R., 1999, ``Distributions of
Individual Susceptibility Among Humans for Toxic Effects--For What
Fraction of Which Kinds of Chemicals and Effects Does the Traditional
10-Fold Factor Provide How Much Protection?'' Annals of the New York
Academy of Sciences, Volume 895, pp. 286-316, December.
Hattis, D. and Barlow, K., 1996, ``Human Interindividual
Variability In Cancer Risks--Technical And Management Challenges''
Human and Ecological Risk Assessment, Vol. 2, pp. 194-220.
Hattis, D. and Burmaster, D.E., 1994, ``Assessment of Variability
and Uncertainty Distributions for Practical Risk Analyses'' Risk
Analysis, Vol. 14, pp. 713-730, October.
Hattis, D. and Froines, J., 1992, ``Uncertainties in Risk
Assessment,'' In Conference on Chemical Risk Assessment in the DoD:
Science, Policy, and Practice, Harvey J. Clewell, III, ed., American
Conference of Governmental Industrial Hygienists, Inc., Cincinnati,
Ohio, pp. 69-78.
Hattis, D., and Minkowitz, W.S., 1996, ``Risk Evaluation: Criteria
Arising from Legal Traditions and Experience with Quantitative Risk
Assessment in the United States:'' Environmental Toxicology and
Pharmacology, Vol. 2, pp. 103-109.
Hattis, D., Banati, P., and Goble, R. ``Distributions of Individual
Susceptibility Among Humans for Toxic Effects--For What Fraction of
Which Kinds of Chemicals and Effects Does the Traditional 10-Fold
Factor Provide How Much Protection?'' Annals of the New York Academy of
Sciences. Volume 895, pp. 286-316, December, 1999.
Hattis, D. Banati, P., Goble, R., and Burmaster, D., 1999, ``Human
Interindividual Variability in Parameters Related to Health Risks, Risk
Analysis, Vol. 19, pp. 705-720.
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Assessment, National Academy Press, Washington, DC.
Rimer, Kelly, 2000, USEPA personal communication to Dr. Barnes,
March 24.
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Ecological Risk Assessment Guidelines'', EPA-SAB-EPEC-97-002.
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Mercury Report to Congress'', EPA-SAB-EHC-98-001.
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to Congress on Residual Risk'', EPA-SAB-EC-98-013, USEPA, Washington,
DC.
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Risk Integrated Methodology (TRIM)'', EPA-SAB-EC-ADV-99-003, USEPA,
Washington, DC.
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Total Risk Integrated Methodology (TRIM)'', EPA-SAB-EC-ADV-00-004,
USEPA, Washington, DC, May.
Thompson, K.M., 1999, ``Developing Univariate Distributions from
Data for Risk Analysis,'' Human and Ecological Risk Assessment 5, 755-
783
USEPA, 1994, Secondary Lead Smelting Background Information
Document for Proposed Standards, Volume I. Final Report. EPA 453/R-94-
024b, Office of Air Quality Planning and Standards, Research Triangle
Park, NC, June.
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Supplements 1 and 2, Order numbers: EPA540R94059 and EPA540R94114,
Department of Commerce National Technical Information Service,
Springfield, VA.
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Development, ``Guiding Principles for Monte Carlo Analysis,'' EPA/630/
R-97/001, March.
USEPA, 1997b, Office of Research and Development, ``Exposure
Factors Handbook'', Vol. I, II, and III, EPA/600/P-95/002Fa, August.
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Risk Assessment'', Federal Register (93)26846-26924, 14 May.
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453/RR-99-001.
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Science Advisory Board Review: Secondary Lead Smelter Source
Category'', EPA Contract No. 68-D6-0065, Work Assignment no. 3-02, EC/R
Project no. HRA-3002, prepared by EC/R Incorporated, January.
______
APPENDIX A
Written Comments of Subcommittee Members
Each member of the SAB's Residual Risk Subcommittee prepared
written comments, centered on the Charge Questions. These materials
were available at the meeting March 1-2, 2000. As a result of the
public meeting, some of the Members altered their original drafts and
asked that the revised versions be included in an Appendix to the
Subcommittee's consensus Advisory. Other Members chose not to submit
their comments for inclusion in the document.
Therefore, this Appendix contains the final written comments from
those Subcommittee Members who chose to submit them for this purpose.
These materials are included in this SAB document so that the Agency
and the public can (a) benefit from the specific comments and (b)
appreciate the range of views represented on the Subcommittee.
While all of these statements are commended to the Agency for
careful consideration, unless a comment is addressed explicitly in the
body of this SAB Advisory, it should be viewed as a statement from an
informed individual, not as the collective view of the Subcommittee.
__________
Statement of Dr. Gregory Biddinger, Exxon-Mobil Company, Fairfax, VA
general comments
1. A Risk Assessment strategy should be designed in alignment with
a risk management process.
Although this may seem like an obvious and generic point, I feel it
is very relevant to make at the onset of these comments. It became
clear during the review of this case study that the linkage between the
ecological risk assessment (ERA) and risk management process is weak
and this weakness is likely due to a lack of clear definition on how
the risk management process will proceed. I believe this lack of
clarity as to how the ERA will be used to support any risk management
decisionmakes it difficult to either design an ERA process that goes
beyond a screening step or to define what are the Next Steps for ERA in
this specific case study.
Recommendation: The footnote on Page 34 of Volume 1 indicates that
OAQPS is working on developing a risk management decision framework for
the residual risk program. That framework should be presented to the
SAB review group to evaluate alignment between the risk assessments and
the risk management process. If the strategy is not final, revisions to
the case study should be deferred until the framework is available.
2. With regards to Ecological Risk assessment, the Agency needs to
define what is meant by the management goal of ensuring that HAP
emissions do not result in ``an adverse environmental effect''.
In order to evaluate the Questions associated with Charge 5, which
is fundamentally, were the appropriate models used correctly, it is
essential to understand what environmental attributes are being
protected and at what spatial scale. In section 5.2.1 the agency sites
Section 112(a)(7) of the Clean Air Act Amendments (CAAA) to say it is
``any significant and widespread adverse effect, which may reasonable
be anticipated to . . . or significant degradation of environmental
quality over broad areas ``. The key and operative terms in these
statements, which require clarification, include (1) significant, (2)
widespread (3) adverse (4) environmental quality and (5) broad areas.
Without a clear definition of what the agency believes is the intent of
these words in the CAAA, it is not possible to assess the correctness
of the agencies actions. Based on an assessment strategy that uses
hazard Quotients (HQ's) and conservative ecotoxicological screening
benchmarks, I would have to assume the Agency's goal is to protect
individuals in all populations and in all places.
Recommendation: The Agency needs to provide the appropriate
clarifying discussion in Section 5 of Volume 1 or through the
development of a technical policy statement which can be cited in this
section.
This exercise should not be viewed as a philosophical exercise. In
developing this clarifying analysis the Agency should identify some
practical rules or decision logic which can reasonably be used to
eliminate source categories from ecological risk. Some (but not the
only) possible rules for not doing an ERA include:
(a) Source categories with a few small facilities in different
regions.
(b) Source categories with a few large facilities but no persistent
or bioaccumulative HAP's.
(c) Facilities in source categories where the primary releases
(e.g. downwash, etc.) are contained to the site.
3. The Ecological Risk Assessment provided is a screening risk
assessment and clearly is not intended to be used for risk management
decisions other than ``No Action'' or ``Further Analysis''. But the
recommendation(s) of the assessors for any followup options are
missing.
The Agency is to be commended for so clearly stating in a number of
places in the case study that the environmental hazard assessment
undertaking is not adequate for making a final risk management decision
that would require controls or other actions to mitigate ecological
risks. This reviewer is left with the question ``What will the Risk
manager be able to do with this analysis?'' If the assessors felt that
more sophisticated or detailed analysis was necessary than they should
have at least said so, even if they believed performing that analysis
was not in the scope at this point in the analysis. The case study is
incomplete with the ERA as provided because the next steps are not
clear. It would not at all be a breach of the risk assessor and risk
manager roles for the assessors to provide some further definition of
what they could do to explore the significance of some of the High HQ's
for various aspects of exposure to key metals (e.g. Antimony) from the
Fugitive emissions at facilities 3, 4 and 13.
Recommendations: The case study needs to include a section on Next
step options with recommendations for the risk manager to consider.
4. The sources of uncertainty in the ERA are understated.
In section 5.7.3 the report reviews the sources of uncertainty
associated with the screening level risk assessment. This review on
uncertainty doesn't completely account for the uncertainty associated
with the exposure estimates. Although it does identify inclusion of
assumption of bioavailability and the exclusion of some pathway it does
not account or refer back to any analysis of the uncertainty associated
with the dispersion and fate. The uncertainty reviewed in section 4
associated with emission rates, dispersion, environmental fate and
pathway analysis could easily overwhelm the uncertainty described in
section 5.7.3.
Recommendation: Section 5.7.3 should recognize the uncertainty
passed through from the dispersion, fate and pathway models.
Charge Question 5: Ecological Risk Assessment
1. Given currently available methods, are the models used for the
ecological assessment appropriate?
In addressing this question it is important to consider my general
comments listed above. The method of using Hazard Quotients (HQ's) and
their summation, Hazard Indices (HI's) to screen ecological hazards is
well established for use in ranking and prioritizing hazards associated
with chemicals. The method has had significant use in new product
design and approval, Risk-Based Corrective Actions at contaminated
sites and prioritization of resources in regulatory programs. As is
well stated in the document such a conservative technique is only used
to remove chemicals from further risk management consideration (i.e.,
the risk is acceptable) or to indicate that there is a need for further
analysis. What this case study does not do is take or even identify the
next steps to refine the analysis of those chemicals that fall above an
HQ or HI of 1.0. One would have expected that some refinement of the
exposure and effects characterization for metals with the highest HQ's
would have been explored. If only to see if less conservative or site-
specific modifications to the exposure characterization or full use of
dose-response data for relevant surrogate species might have brought
the HI exceedances into acceptable ranges. As it stands now we are left
with some significantly high HQ's implying to an unsophisticated
audience that a serious problem exists but without any framing of an
approach to validate or refute such an implication. As a risk assessor,
I recognize that this is only the first step and that these HQ's can
drop orders of magnitude when they are refined, but any lay audience
reading this review and seeing HQ's of 400 with no action recommended
is likely to be alarmed.
Recommendation: The Agency needs to have a process that goes beyond
the initial step of ecological risk assessment that is taken in this
draft case study and either (a) refines the hazard screening process by
improving the estimates of exposure and selecting more appropriate
Toxicity Reference Values (TRVs) or (b) moves into a risk assessment
process that is based on more complete and relevant profiles of
exposure and effects.
2. Are the (available methods) applied correctly?
For the most part yes but one particular aspects of the application
of the HQ approach goes beyond current good practice, that is the
summing of HQ across all chemicals. Suinination of hazards for
chemicals which are operating with the same mode of action on the same
target organ or system may be acceptable. But summarizing across an
array of benchmarks which are based on a variety of endpoints, some of
which are NOAELs and some are LOAEL's is not conservative it is
misleading. I can't see any way that metals and organics could be
considered additive to either the individual or at the population.
The only classes of chemicals in this case study which might allow
such a summing technique would be the summation of HQ's for Dioxin/
furan congeners and the summation of PAH's. But for PAH's it would
still be necessary to break the summations into high and low molecular
weight categories. If this were being done for assessment of acute
hazards I would be more accepting but with chronic toxicity
criteria the endpoints could vary across growth, development,
reproduction and survivorship.
3. Are the ecological benchmarks appropriate?
It is not really possible to completely answer this question from
the information given. The benchmarks that were selected represent the
current State of the practice for screening benchmarks. Many of these
benchmarks were developed for use at contaminated sites to focus
management action on only the serious chemicals of concern. For some of
these lists especially the water and sediment benchmark series there
may be different benchmarks for freshwater and marine systems. Which
were used? The lower of the two? Which ever was available? For
screening purposes this is not likely going to be a problem or
certainly any error of application could be caught in the next round of
refinements.
What is clear is that these numbers should not be used for any
sophisticated risk assessment. The data behind these criteria may well
support a risk assessment but the final ``criteria value'' can only be
used for what has been done here which is to eliminate chemicals of
concern. As HQ's are refined not only should the exposure estimate be
refined to reflect site specific conditions, but also the
characterization of effects should advance from a general benchmark to
an estimate of a toxic threshold based on dose-response data for a
representative or surrogate species.
Recommendation: If the Agency is going to do 174 source categories,
it is worth the effort to develop a matrix of Toxicity Reference Values
(TRV's) for various receptors and endpoints for each of the HAPs that
could be used as screening values. If the complete dose-response
relationships are available, then the same data could be used for (a)
screening (NOAELs), and (b) first risk approximations (EC10 or EC20)
and (c) complete risk distributions (Slope of the dose-response curve).
Although this is not a small task, such a front-loaded effort could
stream-line much of the subsequent source category analyses. If the
Agency were to embark on such a task, I recommend leveraging this
effort with interested industry coalitions.
section specific comments
Section 5.1
The language in paragraph 1 of page 130 is confusing. Suggest
discussing hazard potential rather than potential risks.
Are all of the cited EPA documents available to the public? Is EPA
1999d available? If not should it be cited?
Section 5.2.1
As previously stated in general recommendation No. 2, this section
should be expanded to give the agencies interpretation of the
management goal from the CAAA. This would require defining such terms
as: (1) Significant, (2) Widespread, (3) Adverse, (4) Environmental
Quality and (5) Broad Areas.
Section 5.3
This section is weak because of the lack of interpretation of the
management goal in section 5.2.1. It should be more clearly stated that
the assessment endpoint is No or limited adverse effects to individual
members of sensitive populations. There is no real consideration of
impacts to structure or function. It is only a simple extrapolation to
suggest that if no individual is adversely affected than neither will
the service of its population or the structure and function of
communities and ecosystem it lives in be affected. This assessment is
being done in a fashion to protect individuals; there is nothing wrong
with this if that is the agency's interpretation of adverse
environmental effects. I would suggest it is a bit stringent but for a
screening assessment not atypical. But ultimately the assessment of
residual risk should be at a level of population or higher.
Table 5.1
Citations for Suter et.al. and Will, M.E. et.al. are in conflict
with the reference list.
Section 5.7.2
The discussion incorrectly states that all facilities had HQ's >1
for metals. Facility 2 was not reported in section 5.7.1.1 or in
appendix E to have HQ's >1 with or without fugitives emissions. This
inconsistency needs to be corrected.
Section 5.8
As stated previously, this section should address recommendations
to the manager about the need for followup actions.
Sec. 2.3 The use of lists to identify Persistent and
Bioaccumulative compounds is inappropriate.
Recommendation: The Agency needs to specifically design or adapt a
process to support a Residual Risk process.
______
Statement of Dr. Stephen L. Brown, Risks of Radiation Chemical
Compounds (R2C2), Oakland, CA
These comments are submitted to alert the Subcommittee members to
some issues I will want to discuss in our meeting on points OTHER than
on my main assignment--the uncertainty and variability analysis. Along
with my co-discussant, Dale Hattis, I will be submitting a formal,
although preliminary, writeup on that subject.
overall effort
Overall, I have mixed feelings about the case study. On the one
hand, its overall structure and components are similar to those in many
of the risk assessments conducted in the past few years by or for USEPA
and other environmental agencies such as the California EPA. It
features some standard and generally well accepted models such as
ISCST-3 as well as a detailed multipathway model, IEM-2M. It uses
values for many of the needed parameters that can be found in standard
sources such as the IRIS data base of toxicity information and the
Exposure Factors Handbook. It features a screening level analysis prior
to the main analysis that is designed to help the latter focus on the
most important HAPs and facilities. It includes a variability/
uncertainty analysis and a risk characterization section that are both
recommended in recent EPA guidance on the conduct and presentation of
risk assessments. Many of its assumptions are similar to those in other
EPA risk assessments and therefore consistent with them.
On the other hand, it shares most of the deficiencies of those same
comparison risk assessments and seems to introduce a few of its own.
The conservative assumptions inherent in most Agency risk assessments
are repeated here, and are not adequately balanced by the supposedly
less biased uncertainty analysis. Many of the case-specific assumptions
are inadequately described, let alone well justified, in the text
supplied to the Subcommittee. Some of the predictions of the assessment
are truly astounding (e.g., the blood lead levels calculated when
fugitive dust emissions are included in the assessment), yet there
seems to have been little attempt to identify and correct the problems
that might have led to such conclusions. Even though the case study is
not supposed to be a final assessment for the secondary lead smelter
category, it should have included more thorough quality control to
demonstrate how such an activity would be included in a final
assessment.
In reviewing the assessment, I was struck by how similar the
structure was to assessments conducted under AB2588, the California
statute titled the Air Toxics Hot Spots Act. That act is specifically
designed to evaluate the risks from emissions to air by stationary
sources in California. In that case, the risk assessments are conducted
by the facility itself using guidance provided by the State, and the
assessments are reviewed by the local air district for conformity with
that guidance and accuracy of inputs and outputs. The facility may
submit an alternative assessment with more site-specific information
and less conservative assumptions, including a distributional analysis
in some cases, but the local authority is not obligated to review those
assessments. The standard assessment is usually conducted with the aid
of a computer model such as ACE2588 or HRA96 that was designed to
follow the guidance precisely. Users are allowed to use some site-
specific information, such as stack characteristics and the location of
actual water bodies used as drinking water sources. The models include
not only direct inhalation exposures via concentrations calculated by
ISCST-3 but also via multimedia pathways similar to those in IEM-2M
(although IEM-2M features a more detailed water partitioning model
because it was designed specifically for mercury). Another similar
multimedia risk assessment model designed for emissions to air is TRUE,
developed by the Electric Power Research Institute for assessing fossil
fuel power plants. TRUE includes a mercury model similar in design to
IEM-2M. TRUE is generally less conservative than the AB2588 models, but
is still described as conservative by its authors.
I will now provide comments by Section of the Case Study, more or
less in page order.
introduction
I was disappointed not to see a clearly articulated description of
the decision that this type of risk assessment is to serve. Although
the obvious application is to the residual risk requirements of the
CAAA, it is not clear that EPA knows how it will interpret those
requirements in evaluating the outputs of the risk assessments. For
example, how will risks to highly exposed individuals be weighted in
comparison to the population risks for the whole exposed population?
How will a highly exposed individual be defined? Some fixed percentile
of a distribution? A qualitative representation of such a percentile,
such as the RME? A hypothetical maximally exposed individual or MEI?
What are the quantitative criteria that will trigger further risk
reduction actions? Will those actions be applied to only those
facilities whose calculated risks are above the criteria, or will the
whole category be affected? What level of assurance will be demanded
that the criterion is met in order to State that the residual risk
requirement is met? Without knowing rather well what questions will be
asked, the Agency may not provide useful answers.
In the Introduction, the concepts of the unit risk estimate (URE)
and the reference concentration (RfC) are introduced for inhalation
risks. Although it is clear that both of these numbers are applicable
to continuous lifetime exposure to a constant concentration in air, it
is not clear that calculated concentrations may need to be adjusted for
exposure duration before being used to determine risk using the URE or
RfC. This lack of clarity is not entirely dispelled in the later
section on Dose Response. One stakeholder commenter believes that the
duration adjustment was appropriately made for ingestion exposures but
not for inhalation exposures. More generally, the document could use
considerable improvement in the exposition of what was actually done in
the risk assessment.
initial screening level residual risk analysis
The idea of screening level analyses to focus further risk analysis
on the facilities and HAPs most likely to violate the residual risk
limits is sensible. In fact, multi-level screens may be appropriate,
not just one initial screen. However, the screening analysis as
designed could be improved. First, screening on only inhalation
exposures may give a false sense of security about some facilities or
chemicals if other pathways are in fact substantial contributors to
risk. For some HAPs emitted to air, pathways other than inhalation may
be orders of magnitude more important to risk, particularly if the fate
parameters are such that concentrations in soil will buildup over a
long time before plateauing as removal processes become effective. It
may be necessary to build in some HAP-specific screening-level
multipliers for multimedia effects into the inhalation risk
calculations. On the other hand, it appears that the screen for
secondary lead smelters may have been too conservative in that all
facilities and many of the individual HAPs exceeded the screening
criteria when fugitive dust emissions are included. If a screen does
not screen out anything, it is not very effective.
I am also not particularly impressed with the rationale for
selecting the HAPs to take forward into the multipathway analysis. The
occurrence on a list of ``PBT'' (persistent, bioaccumulative, toxic)
substances is, in my view, a weak substitute for a more quantitative
classification. The actual risk posed by a substance depends on all
three attributes, and others, in a complex way dependent on the actual
conditions of fate, transport, and exposure. It is possible to examine
complex multimedia models and create simplified models that reproduce
their results in a crude fashion, preserving how the effects of half-
life, BAFBCF, and toxicity interact. I again recommend an effort to
create HAP-specific multipliers for screening purposes to help identify
the HAPs that should enter the multimedia assessment.
multipathway residual risk analysis
As stated in my overall impressions, in many ways the multipathway
analysis is equivalent to or better than other regulatory-responsive
risk assessment models, featuring a widely accepted air dispersion
model along with a highly detailed multimedia transport and fate model.
My reservations have more to do with implementation than with overall
concept.
Perhaps my foremost reservation is about the emissions estimates.
As I understand it, no facility has more than one set of tests (e.g., a
1- to 3-day measurement protocol) subsequent to achieving MACT.
Furthermore, there is no evident attempt to correlate the emissions
testing results with any explanatory input such lead throughput during
that period, type of operation, or type of emission control equipment.
(The latter two factors do seem to be used as a guide to extrapolations
from one set of measured results to a different facility, however.) The
document does not discuss any inherent temporal variability, such as
variation in throughput, that might make a snapshot of emissions
inappropriate for calculating an annual average. Perhaps these points
are all discussed in the underlying data sources, but they do not
appear in the current document. As stated in my preliminary comments on
uncertainty, the variability seen in the lead emissions estimates may
be more representative of day-to-day variations than to annual average
variability. There is no evident test of correlations between lead
emission rates and HAP-to-lead emission ratios, that might occur, for
example, if lead emissions followed lead throughput but some other
source (e.g., refractory brick) were the source of a different metal.
The Agency clearly has little confidence in the fugitive dust emissions
estimates--all derived from pre-MACT data, as I understand it--but
still presents risk results as some sort of upper bound on risk. I
contend that such an upper bound is probably not reasonable, given the
failure of monitoring data to confirm the concentrations of lead or
other HAPs offsite.\1\ Unless the Agency is prepared to undertake
empirical studies of fugitive dust emissions from secondary lead
smelters, it might be better advised not to do any quantitative
analysis, simply stating that risks might be higher had fugitive dust
been included. I suspect the same may be true for other source
categories.
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\1\ I am not as sanguine about the virtues of ``model validation''
for the multimedia model as some of the other reviewers of the Case
Study. The model is designed to estimate media concentrations averaged
over some vaguely specified future time period after continuous
operations at MACT conditions with no prior operation. Measurements of
media concentrations that can be conducted in the present, however,
will not capture the effect of future emissions, so there might be
underestimates, and will capture the effect of higher pre-MACT
emissions, so might be overestimates, of the desired validation
quantity. Moreover, the proper temporal and spatial averaging
techniques to make model predictions and measured concentrations
strictly comparable are not easy to specify. Perhaps the best we can
hope for is the identification of gross inconsistencies.
---------------------------------------------------------------------------
Another major concern is the seeming inconsistency between the very
detailed multimedia modeling, which includes such abstruse topics as
sediment-water partitioning with BCF and BAF adjustments to fish
concentrations side-by-side with an inability to locate stacks in
relation to facility boundaries or the assumption of home garden
consumption at a nearby residence. It would seem to entail little work
to telephone the facility for information or make a site visit in
comparison to developing all the inputs for the IEM-2M model, yet such
inexpensive efforts could improve confidence in the risk estimates
greatly.
I generally agree with the hierarchy of choice for selecting
toxicity values to be used in the model. Some commenters have
questioned the use of CaIEPA values as one of the possibilities, but as
a member of the Risk Assessment Advisory Committee, I have examined
that Agency's methods and believe them, on balance, to be as good or
superior to USEPA's. I therefore cannot fault OAR for using the IRIS
values when available and ATSDR, CaIEPA, and HEAST values when IRIS is
silent. Nevertheless, some of the toxicity numbers appear to affect the
results markedly and should be viewed with caution. I am especially
concerned about the values for antimony and for manganese. The antimony
RfC is based on irritation, for which application of standard
uncertainty factors may not be appropriate. The antimony RfD is based
on toxicity endpoints that include blood glucose and cholesterol, not
clinical illness. The manganese RfC is based on ``impairment of
neurobehavioral function,'' an endpoint that is probably to some extent
subjective and less severe than endpoints used to define other toxicity
values. I recommend that EPA's Risk Assessment Forum explore ways to
make the IRIS data base more consistent (perhaps by explicitly
considering severity of endpoint) and to verify any values that seem to
drive risk assessments.
I note the importance of particle size distributions in defining
deposition velocities and other parameters for dry and wet deposition,
which can greatly influence the overall deposition rates and risks for
the same estimated air concentration. I understand that the
distribution for stack and controlled fugitive emissions was assumed to
be similar to those observed in emissions from baghouses, and generally
ranges downward from 10 microns. However, I did not find this
assumption to be stated in the document, nor did I find information on
the assumed distribution for fugitive dust emissions or how the
particle size distributions were translated to deposition velocities.
Generally speaking, reductions in particle size tend to spread
deposition over a greater area but reduce peak deposition at the RME
location. However, if the particle size distribution is dominated by
particles so large that they deposit onsite, reducing the particle size
may actually increase the RME deposition.
Although the actual model inputs include a provision for chemical
degradation after deposition, this mechanism of HAP removal from soil
and water is not mentioned in the text. It should be. I also understand
that the locations of actual water bodies were used for the drinking
water and fish concentration calculations, not some hypothetical water
body co-located with the RME, but again this procedure was not
described in the text. I also am not sure whether these water bodies
are actual, or only potential, sources of drinking water for the local
community. The text is also unclear about the fraction of all produce
consumed that is assumed to be contaminated by the smelter. In some
cases, it appears that a 100 percent assumption was used, whereas
elsewhere, it appears that some standard EPA assumptions less than 100
percent were used. I am particularly concerned that any significant
part of ``grain'' consumption is assumed to be locally produced, at
least for home gardeners.
Non-cancer risks are represented by the hazard quotient/ hazard
index structure that, with all its limitations, is the standard Agency
method for the so-called ``threshold'' toxicants.\2\ The averaging
period for exposures to be used in non-cancer risk assessments is
generally taken to be 1 year in Agency assessments, and that practice
seems to have been followed here. On the other hand, the averaging
period for exposure to carcinogens is taken to be a lifetime, at least
for all carcinogens treated as having linear dose-response
relationships with no threshold. That assumption implies that cancer
risk varies linearly with duration of exposure if daily exposure is
held constant. Although it is reasonably clear that the Agency has
taken duration into account in exposure averaging for the ingestion
routes of exposure, one of the stakeholder commenters has alleged that
the Agency did not do so for the inhalation route, thereby
overestimating risk by the ratio of a lifetime to the assumed duration
of exposure. If true, this error should be corrected. If not,
explanatory text should be added.
---------------------------------------------------------------------------
\2\ The Agency views lead as a non-cancer risk that nevertheless
has no identifiable threshold, and treats it with the IEUBK model. In
reality, toxicity data rarely if ever identify a true threshold and the
RfD or RfC is set as the practical equivalent of no risk. Probably more
at issue is the assumption that risk of cancer is more likely to vary
linearly with exposure at low exposure than is the risk of non-cancer
effects.
---------------------------------------------------------------------------
I would have expected that lead would be the most important risk
from a secondary lead smelter. Cursory inspection of Tables 3.13-3.16
might suggest to the unwary that it is not, because no hazard quotients
are presented for the ingestion routes, and the hazard quotients for
inhalation are not as high as for some other HAPs. However, this
impression is due to two facts that are not as emphasized as they might
be. First, the inhalation hazard quotient is calculated from the
primary NAAQS for lead, which is not purely a health-based number.
Second, the ingestion hazard quotient is not calculated at all, because
the Agency refuses to promulgate an RfD because of the asserted non-
threshold nature of lead. Therefore, the significant analysis for lead
is accomplished through the IEUBK modeling procedure described in
Section 3.3.1.4. From Table 3.23, it can be seen that predicted blood
lead levels can be quite high, especially for the fugitive dust
scenario. Although some discussion of the lack of conformance of these
predictions with observed blood lead values is presented, I think that
the magnitude of these values casts grave doubts about the validity of
the modeling. See, however, Footnote 1 on the difficulties of making
comparisons of model predictions with measurements.
initial ecological screening analysis
Although my expertise is not on the ecological side, this section
struck me as more straightforward, polished and easier to understand
than most of the health risk assessment sections. I note that it is
screening-level in terms of the evaluation of the significance of media
concentrations, but is more-than-screening-level in terms of the
calculation of media concentrations, as it uses the same ISCST-3/IEM-2M
outputs as does the multimedia health assessment. The text suggests
that some organics and acid gases might be included in a more detailed
assessment, but was not clear what reasons would induce the Agency to
include them.
The text states that single point estimates are used to evaluate
media concentrations, but does not State at what geographic location. I
infer that they are probably the RME locations used for the health
assessment, but the location should be made explicit. Averages over
some reasonable range for the organisms assessed might be more
reasonable.
summary and discussion of results
In general, the summary is a reasonable representation of the
procedures and findings from the preceding sections. It also attempts
to discuss a number of issues that might be troubling to a reader,
including the comparison of modeled concentrations with measured ones.
However, my overall impression is that the risk characterization is
more optimistic about the quality of the analysis than is justified.
For example, in Section 6.4, the Agency states: ``For any particular
pollutant, pathway and exposure scenario the resulting distributions
can be used to identify the confidence or probability that risks will
be below or above specific risk levels (e.g., acceptable risk).'' Given
the deficiencies in the uncertainty analysis, let alone those in the
deterministic assessment, I think that is a gross overstatement. Nor do
I think that the uncertainty analysis in any way validated the
determuustic assessment, although that is also suggested here.
I also found the section on children's health gratuitous,
unconnected to the main analysis, and full of overstatement. For
example, the description of newborns having a ``weaker immune system''
omits the temporary carryover immunity from the mother. Although
children eat more food per unit body weight than adults for some foods,
they eat less for others (e.g., fish). And those differences are
already captured in the exposure analysis by age. The fact that cancer
risks, even if due to early life exposures, are expressed later in life
is not mentioned, and the reader is left with the impression of a
potential epidemic of children's cancer due to lead smelters.
Finally, I want to share one procedure that I always followed when
preparing AB2588 assessments. Because I was usually contracted to a
facility owner, I wanted to be sure that the results were not
overstated through error, even if overstated through mandated
assumptions. I therefore always traced back the dominant risk drivers
by pollutant, exposure pathway, and source. I often found simple errors
to be responsible, such as entering a number that was expressed in
different units than needed, or even copying errors. Sometimes the
problem was more subtle, such as including a route of exposure that was
actually not possible for the specific facility. I am not convinced
from reading the Case Study that the Agency took similar efforts to
assure quality, and I recommend it do so. My experience can be extended
for those who are worried about risks being understated by looking at
pollutants that were expected to show higher risks but did not.
__________
Statement of Dr. Deborah Cory-Slechta, Department of Environmental
Medicine, University of Rochester, Rochester, NY
There are two major but related aspects of the residual risk
analysis which are disconcerting. The first is the extensive degree of
uncertainly in the models that have been developed and the total or
cumulative uncertainty of the overall risk analysis. To the credit of
its authors, the models are well thought out progressions that go from
an initial identification of what may be the major contaminants from
the smelters to a multiple pathway analysis that includes multiple
sources of exposures as well as multiple types of receptors. Models for
each component of these pathways feed into the overall derivation of
the resulting HI values. The logic and inclusiveness of this
progression is a major strength of the approach. In addition, the
multiple pathway analysis approach includes consideration of different
age groups, at least early age groups. However, the actual derivation
of the HQ and HI values is almost totally dependent upon substituted
values rather than upon actual data and these are propagated through
the process. Thus, there is really no validation of the model that has
been attempted to date. Certainly no systematic attempt to validate the
model was undertaken; but even the assessment against some known
entities is not considered. The outcome is really presented in the
abstract. While there is repeated discussion of the uncertainties of
the analyses, there is no discussion following either Chapters 3 or 4
of Volume I as to the realities and or the limitations of the findings.
This represents a major weakness of the approach, recognizing what may
be difficulties in obtaining data for the most relevant parameters of
the models.
Also with respect to issues of validating and understanding the
model, there is little indication of how the actual default assumptions
used alter the outcomes and any tests to look at how modifying these
assumptions changes the outcomes, or drives the outcomes. Its not clear
how the validity of the model can be established without understanding
how its components work and influence outcomes.
The uncertainty analysis does little to provide additional
reassurance with respect to the validity of the model. The description
of the outcome of this analysis is presented but with little attention
to its conclusions and to how these conclusions relate to the validity
of the residual risk model, particularly the multipathway analysis. For
example, the plots presented with respect to outcome are somewhat
difficult to comprehend and do not provide a straightforward assessment
of uncertainty. The analyses presented in Chapter 5 of Volume I are
plotted in a manner that is not intuitively obvious and must be
extracted. It is indicated, almost as an aside, that the range
predicted for each cancer or non-cancer effect spans at least two
orders of magnitude. How acceptable is this range? What would typically
be an acceptable range of values from such an analysis?
Some of the predicted values from the residual risk assessment
suggest problems with the default assumptions. For example, the
residual risk assessment predicts blood lead values from Facilities 3,
4 and 13 for infant blood lead levels of over 200 g/dL. These
are extraordinarily high, likely much higher than even encountered in
an occupational context these days. Surely, if such blood lead values
were being generated, they would result in obvious toxic effects and
even lethality in infants and would be evident.
Similarly, the residual risk assessment derives exposure values for
dioxins and furans were found to be considerably lower than those
reported in breast milk in all of the facilities. The residual risk
assessment concludes that this means that emissions of dioxinslfurans
from secondary lead smelters are a minor contributor to overall dioxin/
furan emissions nationwide. Not considered here is the alternative
explanation that dioxinslfurans may be inadequately modeled. The
comments suininarized in No.s 3 and 4 above suggest that by the simple
potential mechanisms of validating the model, it does not work well.
Two major assumptions upon which the residual risk assessment is
based are not adequately justified nor explained. The assumption that
cancer as an endpoint has no threshold, whereas non-cancer endpoints do
exhibit thresholds has no obvious biological basis. It also is not well
supported by more recent reanalyses of data suggesting that Pb
exposures below 10 g/dL (a value used as a type of risk
threshold) may actually produce larger effects than those above 10
g/dl. It is also notably inconsistent with the rest of the
document, since this is certainly not the most conservative approach.
If this assumption is to remain in the residual risk assessment, then
some type of rationale for it should be provided.
Another assumption that is problematic is that the effects of HAPs
are considered to be additive. This may need to be a default assumption
given the relative absence of a data base from which to conclude
otherwise. Assumptions of synergistic or potentiated effects may be
overly conservative and thus not appropriate in this case. Again,
however, some rationale for the reliance on this assumption should be
provided.
The focus on dioxin as a cancer risk really fails to embrace the
fact that these compounds have marked effects on the immune system, the
reproductive system, and perhaps the nervous system as well. This
component of dioxin/furan effects should be included in the non-cancer
effects.
Some of the distinctions between the subsistence farmer and the
home gardener seem somewhat arbitrary. For example, why wouldn't the
home gardener also be ingesting animal products, in fact those grown on
the subsistence farm; local processing and distribution of these
products certainly occurs.
One major component of the document that seems to be missing is any
real discussion of the outcomes of the multipathway analysis with
respect to known values as determined from other sources for emissions
of the various metals and organics chosen as well as any exposure data
for these compounds in smelter workers and or groups living around
smelters. How do values computed relate to any known emission or
exposure data?
A related point is that the document does not really put the risks
generated into an adequate public health context. What do these derived
risk estimates mean with respect to public health? The values generated
are presented without really providing any discussion of their
relationship to known toxicity levels for these compounds.
A minor point, but wouldn't chicken be a better choice than pork
with respect to total human consumption in the category of animal
product ingestion?
______
Statement of Dr. Thomas J. Gentile, New York State Department of
Environmental Conservation, Albany
1. Overall: Is the methodology that the Agency applied in this risk
assessment consistent with the risk assessment approach and methodology
presented in the Report to Congress? Are the assumptions used in this
risk assessment consistent with current methods and practices?
The risk assessment methodology presented in the case study is
consistent with the framework described in the Report to Congress (RTC)
with some significant exceptions. Overall, the case-study approaches
incorporates the iterative approach (e.g. refine the risk assessment by
reducing the conservatism by including site-specific detail). It
carefully identifies the assumptions and impacts of the assumptions on
the risk estimates presented. In addition, the public health risk
assessment is consistent with current methods and practices. Although I
have some concerns about the adequacy of the ecological assessment,
these concerns may be due to my unfamiliarity with the current State of
the science about ecological risk assessment practices.
However, the case study does not go far enough in providing site-
specific information to make the important risk management decisions
concerning the adequacy of the NESHAP to protect public health and the
environment. There was an attempt to incorporate some site-specific
information (e.g. facility compliance stack test, State stack test,
receptor locations, ambient measurements and local blood lead levels),
but more site specific information (e.g. the degree of partial or total
fugitive emissions enclosures, specific terrain information for
receptor modeling, soil sampling results for metals in the local areas)
needs to be obtained by working with State and Local Public Health and
Environmental Agencies and industry. This point is evident when a
comparison is made between the screen and refined risk estimates for
inhalation only exposure (Table 1).
Table 1.--A Comparison Between The Refined And Screen Inhalation Cancer Risk Estimates For The Facilities
Selected For Refined Analysis
[All Risk Estimates Are Cases Per Million]
----------------------------------------------------------------------------------------------------------------
Risk
Initial Refined Refined Reduction Risk Reduction w/
Facility Screen Screen w/o Screen w/ w/o fugitives
fugitives fugitives fugitives
----------------------------------------------------------------------------------------------------------------
2................................... 6000 10 52 600 115
3................................... 9000 5 2240 1800 4
4................................... 6000 268 6950 22 risk increases
13.................................. 10000 16 130 625 7
----------------------------------------------------------------------------------------------------------------
The increase in risk for facility 4 as a result of the refined
modeling raises concerns, which may go beyond the lack of refinement of
the fugitive dust emission estimates in the refined analysis. This
needs to be explored in greater detail in the case-study. The obvious
differences which impact the risk assessment between facility 4 and the
others is the size of the facility as determined by the number of
emission points (n=13), the furnace type and the closer receptor
impacts (Table 3.7 in case-study). However, the most troubling aspect
is that Facility 4 had stack test data reported for all of the HAPs
which were assessed in the refined screening exercise. It also had the
smallest incremental reduction in risk (22 times) when just the process
and process fugitive emissions impacts from inhalation exposure are
considered. The other issue is that Facility 3 also had stack test data
reported for all of the HAPs which were assessed in the refined
screening analysis and had the largest incremental reduction in risk
(1800 times). An in depth analysis of these large differences in risk
reductions (1800 versus 22) needs to be examined more closely in the
case study. In addition, they have probably been subject to stringent
State air toxics requirements under the California Air Toxics Hot Spots
Program. Is there a State Air Toxics Hot Spot Risk Assessment for these
facilities? If it is available has OAQPS conducted an independent
evaluation of the results and actions which were taken to reduce risk?
This is extremely important since the refined analysis for
facilities 3 and 4 was based more site specific emissions information.
The increased risk observed for facility 4 in the refined analysis
indicates that the initial screening assumptions may not be overly
conservative in all cases. The only way to check this would be to
obtain some basic site-specific information to insure that the
parameters used in the initial screen are always going to be
conservative for all facilities.
In summary, a detailed site specific description of the four
facilities selected for the refined analysis should be suininarized and
included in volume 1. The brief discussion in section 3.1.1 is
inadequate and should be expanded. This qualitative expansion should
include cross references to other sections where site specific data is
used in the refined analysis. For example, the use of actual stack
characteristics for the refined analysis which is found in Table 3.3,
the use of local met data which is found in Table 3.4 and the use of
actual receptor locations which is found in Table 3.7. This would place
all site specific or cross references to site-specific information into
one important place and would help the reader conceptualize the
differences between the facilities under evaluation.
In context of the framework presented in the RTC, it appears that
the refined analysis can not answer the question: Is human health risk
acceptable? The fugitive emissions issue (e.g. lack of refinement) and
the lack of site-specific information clearly result in negative answer
to the question: Are information and analysis sufficient to evaluate
management options? This answer indicates that a further refinement of
the case-study or another iterative step is needed before an evaluation
of the risk management options can be considered.
The Agency is mandated under Section 112(f) to conduct the residual
risk assessment and make a decision to implement further regulation or
to make a decision that no further regulation is needed. In response to
the previous SAB review of the RTC, the Agency responded that, ``the
decision made with the results of the screening analysis is no further
action or refine the analysis, while the decision made with the results
of the more refined analysis is no further action or consider
additional emissions control.'' As discussed above, the results of the
refined analysis provides the same answer as the initial inhalation
screen, that a more refined analysis is needed. Therefore, the case
study has not achieved the ultimate decision objective and another
level of analysis or iteration is required. The case study should do a
more in-depth refined analysis or an additional step-wise iteration to
improve the case study for risk management decisionmaking.
An examination of the initial screen results indicates that it has
provided important information about which hazardous air pollutants
(HAPs) need to be considered in the multipathway and refined analysis.
However, the results from the above Table are disconcerting. How can
the refinement and the removal of conservative assumptions and HAPs
from consideration result in an increased inhalation risk for receptors
around facility 4? It is important to narrow the scope and refine the
residual risk analysis in the first step, however, extreme caution must
be exercised when eliminating HAPs and facilities from consideration as
a result of the initial screening. It is clear that the use of post
NESHAP emission rates in the initial screen would provide a better
starting point for the case study.
The impact of consolidating emission points into a centroid
emission point needs to be carefully considered and analyzed. The
Office of Air Quality Planning and Standards (OAQPS) should evaluate
the work that has been conducted with the Office of Pollution
Prevention and Toxics (OPPT) on the Risk Screening Indicators Model
concerning the use of centroid emissions locations versus the use of
facility specific stack and location parameters. An analysis conducted
by OPPT found that the impacts in the area close to the facility fence
lines was underestimated by a factor of three to seven when the
centroid was used to estimate emission impacts. As distance from the
facility increased the centroid modeling provided more consistent
predictions when compared with the model using actual stack emission
parameters and location characteristics. Therefore, some of the
conservatism of the initial screening and the refined screening
exercises may be questionable if receptors are in close proximity to
the facility fencelines.
The selection of facilities for the refined analysis needs to be
placed into some type of risk management framework. These facilities
were obviously selected since they represented the highest risk (e.g.
cancer risk > 9000 in a million and HQ > 70). However, a defined
process is needed for selecting which facilities will be included in
the refined analysis. For example, if the 100 in a million cancer risk
value was used only 2 of the 29 facilities would pass the screening
criteria. The use of this cancer risk range would be consistent with
the benzene decision and the Commission of Risk Assessment and Risk
Management (CRARM) recommendations by having the total cancer risk from
the facility being in the range of less than one to one hundred in a
million for the screening assessment. In addition, if a hazard quotient
of 10 is used as an action level for the screening assessment as
recommended by CRARM, then a decision to eliminate facilities 6, 9, 12,
20, 25 and 29 for further analysis of noncanccr health effects can be
made. One can construe from the selection of only four facilities that
a decision of no further action may be made for the other 19 facilities
based on the initial screening assessment.
In summary, there is a need to gather more site specific
information for the initial and refined analyses than what was gathered
and presented in the case-study.
The RTC discusses the need for including background risk and
discusses the difficulty associated with this specific issue. The case
study does not address background risk issues around any of the 23
facilities in the human health risk assessment. This is serious
omission from the case-study and there is a need to attempt to address
this issue at a minimum from a qualitative and quantitative point of
view, well beyond the comparisons made in Chapter 6. No assessment of
background risk seriously impacts statements about the conservative
nature of the refined screening assessment.
I disagree with the statement on page 134 of the case-study that
any attempt to include background concentrations in the ecological
assessment ``. . . were beyond the scope of this assessment.'' This is
a critical part of the ecological risk assessment since these
facilities have been probably impacting the local ecosystems for a long
time prior to the addition of NESHAP controls. An assessment of
background risk in addition to the screening level assessment is
absolutely necessary before any decisions can be made about the
significance or conservativeness of the ecological risk assessment.
The RTC also discusses the assessment of acute effects from short-
term HAP exposure. The case study contains no discussion or assessment
of acute effects from HAP emissions for this source category.
2. Model Inputs: Are the methods used to estimate emission rates,
and the method used to estimate species at the stack appropriate and
clearly described?
The methods used to estimate emission rates for the initial screen
and refined analysis are clearly described. However, there is a concern
that the emission rates used for the lead to metal HAP ratios in the
initial screen are biased low based on the actual stack test results
from facilities 3 and 4. A comparison of the lead/HAP metal ratios used
in the initial screen and refined analysis are presented in Table 2.
Table 2.--A Comparison Of The Lead To HAP Metal Ratios Used In The Initial And Refined Screening Analysis
----------------------------------------------------------------------------------------------------------------
Initial
Initial Refined Screen Refined
Metal HAP Screen (Process) Process Process
(Process) Fugitive Fugitive
----------------------------------------------------------------------------------------------------------------
Arsenic................................................. 0.09 0.31 0.03 0.035-0.098
Chromium................................................ 0.05(1) 0.00048 0.01 .00013-0.0014
Cadmium................................................. 0.02 0.031 0.01 0.02-0.045
Nickel.................................................. 0.08 0.179 0.06 0.13-1.99
----------------------------------------------------------------------------------------------------------------
(1) The ratio for the initial screen is total chromium and for the
refined analysis it is hexavalent chromium. An adjustment of the
initial screen total chromium values using the 1 percent assumption as
hexavalent provides almost the same value used for the refined process
and process fugitive emissions.
The differences between the arsenic and nickel ratio values used in
the initial screening analysis and the refined screen analysis clearly
undermines the conservativeness of the initial screen risk results
presented in Tables 2.4a and 2.4b. If the stack test results from
facilities 3 and 4 are post NESHAP , then a decision should have been
made to use those results in the initial screen versus the median
values estimated from Background Information Document (Table B1.3--
Appendix B).
The Agency should consider requesting stack emissions test for
process and process fugitive at some of the facilities in order to
obtain better emission estimates for use in the screening assessment
case-study.
The Agency carefully needs to reevaluate the fugitive emissions
rates since the modeled annual concentrations of lead with fugitives in
Appendix C are unrealistically high for facilities 3 and 4. There is a
need for site specific information on the effectiveness of fugitive
emissions control after the implementation of the NESHAP housekeeping
standards. Fugitive emissions from this source category are an issue
and need to be carefully evaluated. In 1987, there were two exceedances
of the National Ambient Air Quality Standard (NAAQS) for lead (1.5
g/m3) in the vicinity of a secondary lead smelter. The
elevated lead concentrations (2.46 and 1.61 g/m3) at the
monitor were the result of malfunctioning emissions control equipment
and fugitive emissions from the plant. Monitoring of lead around the
plant was increased by the addition of two downwind monitors. The plant
upgraded the process emission controls, but the concentrations of lead
were still elevated, but below the NAAQS when compared to other
monitoring sites in the State. Further investigations concluded that
fugitive emissions from the plant were a problem that needed to be
addressed. The entire facility was enclosed and placed under negative
pressure. HEPA filters were installed on all air exchange units and
other housekeeping practices were required. This facility currently has
16 emission points. The annual geometric mean of lead at one monitoring
site dropped from a high of 0.71 g/m3 (1987) to 0.06
g/m3 (1993) after all of the facility upgrades were in place.
The highest quarterly average measured at the two remaining monitoring
site in 1996 were 0.06 g/m3. These two monitors are located
275 meters from the facility fence line. The third site was shutdown at
the end of 1995.
The incorporation of this type of information into the case study
and the refined screening analysis will result in a more informed risk
management decision for this source category.
3. Models: Does the risk assessment use appropriate currently
available dispersion models at the screening level and at the more
refined level of analysis? Are the models applied correctly? Given the
State of the science, does the risk assessment use an appropriate
multipathway model? The assessment uses the IEM-2M model, with some
modifications. Is the IEM-2M model appropriate for use in this
regulatory context? With regard to the modification and application of
the model, did EPA appropriately modify the model for use in this risk
assessment, and did the Agency apply the model correctly? Is there
another model or another approach, that is available at this time that
EPA should consider?
The decision to use facilities 2,3,4, 13 because these represented
facilities with the highest excess cancer rate and highest hazard index
based on the initial screening produced a situation where only simple
terrain would be used in the refined analysis. This process could have
biased the modeling results to underestimate impacts at other
facilities, with complex terrain, which were not designated for refined
analysis. The Agency should reevaluate if any of the 29 facilities are
in areas of complex terrain.
The exposure inputs into the IEM-2M and IEUBK model are
conservative which is clearly acknowledged by the Agency throughout the
case study. The Agency should continue refine the risk assessment using
site specific information as discussed in many of my other comments.
There is a strong need for another iteration to refine the case study
which is acknowledged by the Agency in section 6.7. The case study
should remain a Pre-Decisional Document until the next iterative
refinement is conducted. OAQPS should work diligently with State and
Local Health and Environmental Departments, the Agency for Toxics
Substances and Disease Registry, Industry and the EPA Regions to
further refine the case study. This step is absolutely necessary before
any decision about unacceptable risk is made for the majority of the
facilities identified in the case-study. The uncertainties associated
with the fugitive emission parameters are the driver for a more
detailed risk assessment within the source category. This need is
discussed by CRARM on page 23 of the RTC.
4. Choice of Receptors: The Agency identifies the home gardener as
the appropriate receptor to estimate risk to the residential population
and the farmer to embody high end risk estimates. Are these receptors
appropriate for this task?
The receptors identified by the Agency are appropriate and
adequately represent the maximum individual risk (MIR) concept which is
discussed in the RTC.
5. Ecological Risk Assessment: given the currently available
methods, are the models used for the ecological assessment appropriate?
Are they applied correctly? Are the ecological benchmarks appropriate?
The case study does not include a discussion of other ecological
stressors (e.g. criteria pollutants) which may have an impact on the
surrounding ecosystem. The effect of this omission on reducing the
conservativeness of the ecological risk screen is mentioned on page
147. However, any refined analysis of ecological risk is going to have
to account for these additional ecosystem stressors, especially the
effects on terrestrial plants exposed via direct contact with criteria
pollutants (in this case sulfur oxides) in the ambient air.
6. Health Risk Assessment: Given available dose-response
information, is the hierarchy presented in the assessment appropriate
(see especially footnote #6, section 2.21)?
The hierarchy presented in the assessment is appropriate. I agree
with the use California Environmental Protection Agency values over
HEAST values for all of the reasons outlined in footnote No. 6.
For each chemical included in the assessment is the choice of dose
response assessment appropriate?
Overall, the choice of the available dose-response data used in the
case study is appropriate. I have concerns about the elimination of
HAPs from consideration in the case study if they have no available
cancer or noncancer public health values. Seven organic HAPs are
eliminated from consideration in the case study. It is difficult to
assess the impact of the elimination of these organic HAPs from the
case study. However, the effect may be negligible since emission rates
in Appendix B for the organic HAP emissions omitted from consideration
are low. The Agency should consider the development of default or
surrogate values based on the available toxicity information or
structure activity relationships with other HAPs which have dose
response data.
Why is propanol identified as a HAP in the case study? I can not
locate it on the list of 188 HAPs identified by the Clean Air Act.
The application of the use of risk ranges for benzene and 1,3-
butadiene in the initial screen needs to be discussed. Do the cancer
risk results presented in Table 2.3 use the high or low end of the
range?
The use of only 25 percent of the inhalation unit risk estimate for
nickel subsulfide needs to be explained in greater detail, since it
will have a large impact on the total cancer risk estimates in the
case-study.
Are the dose response assessments appropriately incorporated into
the assessment?
Yes, the available dose response assessments are appropriately
incorporated into the assessment, with a few exceptions as noted above.
7. Uncertainty and Variability Assessment: Did the assessment use
the appropriate currently available methods to identify the variables
and pathways to address the uncertainty and variability assessment? Are
the methods used to quantify variability and uncertainty acceptable?
Are there other, more appropriate methods available for consideration?
8. Results Presentation: Does the document clearly present and
interpret the risk results? Does it provide the appropriate level of
information? Do the figures and tables adequately present the data? Do
the formats provide for a clear understanding of the material?
It is very difficult to present such a large amount of information
in a clear and concise manner. The case study does a good job of
presenting and interpreting the risk results. The discussion of the
initial inhalation screening results should include a discussion of how
the maximum and minimum risk values presented in Table 2.3 were
defined. The Agency should indicate that they are simply the range of
estimates determined for all 29 facilities.
The Agency should consider using a consistent cancer risk
expressions in the narrative of the case study. The lay reader will be
confused by the constant interchangeable expressions of cancer risk.
For example, the use of the expression eight in a ten thousand should
be changed to 800 in a million. This will allow the lay reader to place
the results into the context of the less than one in one million
expression which appears in the Act and throughout the case study.
The identification of the key issues and assumptions are clearly
identified in the result sections of the the initial inhalation screen,
the refined multipathway screen , the variability and uncertainty
analysis, and the ecological screening assessment. The addition of a
discussion about a few key issues concerning the lack of a background
risk analysis and the effects of the adjustment of the nickel
inhalation unit risk estimate could be added to the key issues
identified in Section 3.3.2.
The tables and figures used throughout Section 4 provide a concise
and well thought out approach for the presentation of variability and
uncertainty for each scenario evaluated. They allow the reader to
evaluate the broad spectrum of risk and the impacts of the various
exposure parameters used in the refined multipathway risk assessment.
These tables and figures significantly enhance the comprehendability of
the variability and uncertainty assessment results. The inclusion of
the point estimates in Tables 4.5 and 4.6 is an excellent way to
concisely present information to the risk manager. The tables and
figures provide the risk manager with the ability to view the broad
spectrum of risk predictions, which includes the average exposed
individual (AEI), the adjusted maximum individual risk and the maximum
exposed individual (MEI).
Tables 6.1 and 6.2 provide a good overview summary of the final
results for the refined multipathway risk assessment. I have some
concerns about Section 6.2.1 Comparison of Modeled Concentrations with
Measured Environmental Concentrations. As discussed through out my
comments this section can be greatly enhanced and another iterative
refined multipathway risk assessment step which relies on more site
specific information should be added to the case study.
The effort which will be needed to gather the relevant information
for this next step should not be considered overwhelming or beyond the
scope of the case study. It should be considered as a necessary
refinement which needs to be conducted before the case study becomes a
public document. The discussion in section 6.2.1.1 needs to be
expanded. The pre-NESHAP monitoring data from New York indicates that
the NAAQS for lead can be exceeded and that the stringent control of
fugitives can result in a dramatic lowering of ambient concentrations
of lead and probably other metal HAPs in the vicinity of secondary lead
smelters. Table 6.7 should be modified by locating the distance to the
monitors and include a brief discussion of siting issues (e.g.
predominate downwind or upwind monitoring location) before any
comparisons are made. The same point can be made for the comparisons of
the surface waters concentrations. However, the Agency does
appropriately acknowledges that the comparisons in Table 6.8 are not
meaningful.
Section 6.2.1.5 needs to be expanded since it provides information
on an excellent biomarker for potential exposure (e.g., blood lead
levels). The inclusion of this type of information would greatly
enhance the case study. The CDC and State Health Departments should be
consulted to find out if there is any other information on blood lead
levels in children who reside in communities that are in close
proximity to secondary lead smelters.
In summary, there is a strong need to gather and evaluate more site
specific information using the risk assessment tools presented in the
case study before any final risk management decisions can be made for
this source category. The case study should undergo another iteration
before being released to the public.
editorial notes
The overview presented in section one, the case study, is very
good.
Section 2.2 needs to include the chemical abstract service registry
numbers and the identity of the chemicals as they are primarily
identified in Section 112 (b) of the Clean Air Act (e.g., 2-methyl
phenol is identified by 112 (b) as o-creosol, iodomethane should be
identified as methyl iodide, etc.)
Table 6.8--the units (g/l) are missing.
__________
Statement of Dr. Dale Hattis, Clark University, Worcester, MA
Below are my updated responses (following discussion at the
meeting) to the questions posed to the Secondary Lead residual risk
review Subcommittee:
Charge Question 1. Overall--Is the methodology that the Agency
applied in this risk assessment consistent with the risk assessment
approach and methodology presented in the Report to Congress? (EPA-453/
R-99-001)? Are the assumptions used in this risk assessment consistent
with current methods and practices?
Response. I have very considerable difficulty making an appropriate
response to the first part of this question. I was not provided with a
copy of the Report to Congress that is specifically referred to. Fairly
recently, I was sent a copy of a substantial earlier SAB review of that
document from which I can make some inferences about the risk
assessment approach and methodology that was presented in the Report to
Congress. However there does seem to be very significant commentary in
the SAB review of the need to ``validate'' models, and to conduct
appropriate analyses of the population variability of regulated risks
and give a fair estimation of the uncertainty in the variable risk
distributions. The current document, though very extensive in many
ways, does not seem to reflect a serious effort to assemble and analyze
a substantial body of post-MACT emissions and exposure (e.g., community
blood lead) information that could be juxtaposed with the emissions
estimates made in the early 1990's when the MACT standards were set.
The documents do not appear to describe a systematic search for such
information, do not present the specific emissions information that was
collected, and do not document in nearly adequate detail the specific
analyses that were done with the emissions information. There is no
visible attempt to juxtapose model projections of either emissions or
exposures (e.g., for blood lead) with such data and to form the bases
for an updated set of distributional exposure and risk projections.
There is a great deal of discussion in the SAB review, and in the
EPA residual risk assessment, of the need to conserve scarce EPA
resources by limiting the analysis in various ways (by structuring the
analysis in a series of tiers beginning with generic conservative
assumptions, restricting the HAPs covered, the facilities examined in
detail, etc.). Sadly the implementation of this approach does not seem
to have lead to an economical analysis that can be said to have
succeeded in producing meaningful insights into the likely level of
risk posed to real people in the immediate vicinity of these
facilities. There is no more expensive analysis than an analysis that
does not produce results that can meaningfully inform public policy
choices. The screening level analysis as it stands probably is adequate
to focuses EPA's attention on lead and a few metallic HAP's, and away
from the great majority of organic HAP's, but that result probably
could have been foreseen with considerably less work than appears to
have been devoted to this project. Certainly something is seriously
amiss when the document can show projections of essentially lethal
blood lead levels (200 g/dL and above) for the case where
fugitive emissions are included--and very significant blood lead levels
(68 g/dL) even without fugitives for one of four modeled
facilities--without that leading to some attempt to pursue the issue
with blood lead observations or some deeper conclusion than that the
fugitive emissions estimates are probably ``conservative''. Maybe they
are ``conservative'', but then to blithely exclude both the fugitive
emissions and all exposures to lead entirely from the ``variability/
uncertainty analysis'' without further reappraisal of the source of the
apparent estimation problem seems to turn the screening results on
their head. Any ``tiered'' analysis procedure that leads the
investigators to exclude such a major source of concern as lead from
important parts of the secondary lead smelter analysis has a serious
fundamental problem, at least as implemented here. This is particularly
true in the light of the fact that emissions of the other HAP's that
are included in the variability/uncertainty analysis are estimated as
ratios to lead.
The context of this residual risk analysis is a long term possible
consideration of the need for emissions control measures that go beyond
the available control technology-based standards that were mandated in
the first round of controls following the passage of the 1990 iteration
of the Clean Air Act. Almost by definition, when you are building the
informational basis for considering the need for technology-forcing
measures, you need to have data that would be sufficient to support
decisions that might involve very substantial technical and economic
restructuring of an industry. At the same time, the context also
involves considering the possibility that appreciable residual risks
remain for people in communities surrounding these facilities that mean
that the promise of the 1990 Act to provide an ample margin of safety
for health protection is still not being fulfilled 10 years after the
promise was made. This context demands that EPA take the time and
devote the resources needed to fairly assess the current public health
problem posed by these facilities. Otherwise no actions based on such
an analysis are likely to survive Congressional and Judicial oversight.
Charge Question 2. Model Inputs--Are the methods used to estimate
emission rates, and the method used to estimate species at the stack
appropriate and clearly described?
Response. Briefly, no. The primary data should be provided in the
document and the detailed analysis steps should be given in sufficient
detail to allow an informed reader to reproduce the analysis. My
understanding from the extra documents that have been provided to me in
the context of the variability/uncertainty analysis is that the
existing data base is not extensive--onsisting apparently of three
``runs'' (of undetermined duration) measuring Lead, Arsenic, Cadmium,
and Nickel emissions from various stacks at two different facilities--
constituting in all about 168 separate measurements if I have counted
correctly. For a large number of other HAP's and other facilities my
understanding is that there is some additional information available
from recent (post 1990) measurements for four facilities, but that the
primary sources of estimates of emissions is the 1994 Background
Information Document for setting the MACT standards. The bases of these
estimates and their applicability to current conditions is not
discussed.
In addition, the authors should take a more creative approach to
assembling other types of data relevant to emissions than they have
apparently considered. For example, to estimate fugitive emissions, one
clue might be air exposure levels measured for workers in this industry
by OSHA industrial hygienists. [Some helpful background on the history
of air and blood lead levels in the industry can be found in a couple
of past reports I helped do for the Office of Technology Assessment--
Goble et al., (1995, 1983)]. Such air levels, when combined with
general ventilation assumptions and baghouse capture efficiencies,
should provide some basis for new estimates of at least some process
fugitive emissions, as should air measurements from environmental
monitoring conducted near the facilities, and children's blood lead
measurements that are routinely collected by agencies in several
states, and which may therefore be available for communities near the
facilities under study. In addition, it should allow some estimation of
fugitive emissions from other parts of the process than the battery
breaking and materials handling steps that are presently included as
contributing fugitives in the current process flow diagram. What
happens to the air around the workers working at other steps than the
first two? Is it captured and treated to remove some dust? With what
efficiency? Additionally, it would seem sensible to make systematic
comparisons of observed community air levels with those predicted from
the dispersion models.
Charge Question 3. Models--Does the risk assessment use appropriate
currently available dispersion models both at the screening level and
at the more refined level of analysis? Are the models applied
correctly? Given the State of the science, does the risk assessment use
an appropriate multipathway model? The assessment uses the IEM-2M
model, with some modifccations. Is the IEM-2M model appropriate for use
in this regulatory context? With regard to the modification and
application of the model, did the EPA appropriately modify the model
for use in this risk assessment, and did the Agency apply the model
correctly? Is there another model or another approach, that is
available at this time that EPA should consider?
Response. These questions cannot be fairly answered from the
information provided. There was just not a sufficient presentation of
the assumptions inherent in the IEM-2M model for me to evaluate it. I
was provided with very large spreadsheets of the model, but without a
great deal more time and appropriate documentation of the structure and
assumptions built in to the model it is just impossible for me to make
a sensible evaluation. I don't know and cannot easily infer, for
example, how it differs from other multimedia models that are
available, such as CALTOX.
Charge Question 4. Choice of Receptors--The Agency identifies the
home gardener as the appropriate receptor to estimate risks to the
residential population and the farmer to embody high end risks. Are
these receptors appropriate for this task?
Response. I'm not at all convinced of this. My impression is that
the chief pathway responsible for transferring gasoline air lead to
children when gasoline lead was still allowed was a dust-hand-mouth
pathway. It seems to me that this pathway, together with more recent
information on the efficacy of community soil cleanups in reducing
blood lead levels, needs to be evaluated as part of any fuller analysis
of the issue. I understand EPA's desire to exercise its IEM-2M models,
and this should certainly be one part of the analysis, but key issues
need to be addressed, such as the persistence of dust contaminated with
lead and other metallic HAP's in neighboring communities, rates of
exchange between outdoor dust and indoor dust, and the magnitude and
duration of exposures that result from emissions and deposition of
indestructible metallic compounds in urban and other communities.
Charge Question 5. Ecological Risk Assessment Given currently
available methods, are the models used for the ecological assessment
appropriate? Are they applied correctly? Are the ecological benchmarks
appropriate?
Response. This is not my area of expertise, and I have not
evaluated this portion of the document.
Charge Question 6. Health Risk Assessment--Section 3.4.1 of the
Report to Congress identifies several data sources that the Agency
would draw upon for choosing dose response assessments to be used in
residual risk assessments. The Report also states that EPA will develop
a hierarchy for using such sources. Given available dose response
information, is the hierarchy presented in this assessment appropriate
(see especially footnote No. 6, section 2.2.1)? For each chemical
included in the assessment, is the choice of dose response assessment
appropriate? Are the dose response assessments appropriately
incorporated into the assessment?
Response. I do not have the cited Report to Congress, and I have
not thoroughly evaluated this aspect of the document. However, I would
suggest that at least for lead, where there are quantitative estimates
of relationships between children's blood lead levels and IQ, that the
results be taken to estimate likely individual and population aggregate
impacts in quantitative terms--how much relative deficit for how many
kids. Additionally, I believe that cancer impacts can and should be
evaluated in population aggregate terms as well as in terms of risks to
particular percentiles of the estimated exposure distributions. This
would allow decisionmakers in Congress and EPA to assess the public
health productivity of investments made under the residual risk
provisions of the Clean Air Act.
Charge Question 7. Uncertainty and variability assessment--Did the
assessment use appropriate currently available methods to identify the
variables and pathways to address in the uncertainty and variability
assessment? Are the methods used to quantify variability and
uncertainty acceptable? Are there other, more appropriate methods
available for consideration?
Response. Although there are some glimmers of creative analysis of
data in the uncertainty/variability portion of the effort (e.g. the
attempt to calculate metal HAP/lead ratios over a longer time period
than covered by the directly observations), the current analysis is
very disappointing in numerous ways. First, the scope and objectives of
the analysis fall far short of what any sensible decisionmaker will
wish to have in order to make informed choices under the residual risk
mandate of the 1990 Clean Air Act. To fulfill the mandate of the Clean
Air Act, EPA needs to not only be confident that it has addressed the
most significant hazards posed by the industry under study, but to
define what it means by an ``ample'' or ``adequate margin of safety''
in distributional terms, (e.g., X level of probability of harm of a
particular type or severity for the Yth percentile of the exposed
population with Z degree of confidence-See for example Hattis and
Anderson, 1999; Hattis and Minkowitz, 1996). EPA then needs to develop
an analysis that addresses the likely real variability and fairly
appraised uncertainty for at least the HAP's and exposure pathways that
are thought to pose the greatest potential for public health harm for
the industries studied. In the present context, omission of the
variability and uncertainty of lead exposures and risks, and omission
of some analysis of the uncertainty in fugitive dust emissions and
exposures means that the analysis is substantially irrelevant to some
of the most important concerns that arise from the earlier screening
and multipathway efforts.
The failure to distinguish variability from uncertainty in the
present analysis almost guarantees confusion. Variability and
uncertainty are different things and
require different techniques for estimation. It is a shame that the
individual variability in estimated exposures is essentially completely
neglected even though existing dispersion modeling techniques, combined
with data on the population distributions around the studied
facilities, could readily produce such information. This
information would seem central to the required analysis. The fact that
it is not undertaken, at least at this stage in the development of the
project, suggests that the current variability/uncertainty analysis is
largely a placeholder for some later effort that, it is hoped, will be
planned as a more central part of some future analysis.
A second major problem is that the current analysis does not follow
existing EPA guidelines on the documentation and presentation of
distributional analysis. Those guidelines, drawn up in part at
workshops that I attended, emphasize that the model itself and
derivations of distributions used in the analysis must be transparently
presented in sufficient detail that a reviewer can reproduce them. I
have recently received several spreadsheets that contain portions of
the model, but in the very limited time available I have not been able
to get them running sufficiently to even examine the model structure,
distributional assumptions, and correlation/dependency assumptions
made. The document itself should have included as an appendix not the
endless display of results for each stack, but the spreadsheet model
equations, and the mathematical form of the distributional assumptions
that were used.
In summary, in the present effort, the uncertainty/variability
analysis appears to have been an afterthought, perhaps undertaken at a
late stage in the development of the principal results. Unless analyses
of variability and uncertainty are undertaken integrated into the warp
and woof of the primary study, they will likely continue to be
unsuccessful and unsatisfactory in illuminating the major issues
involved in the evaluation of the real choices facing EPA
decisionmakers, Congress, and the public.
Some more technical suggestions can be made for pursuing the
probabilistic analysis in future work:
(a) In assessing the distribution of metal HAP to lead ratios, the
analysts should explore the possibility that some air exhaust streams
might be systematically different than others. In particular arsenic,
which is more volatile than the lead and most other inorganic HAP's may
appear in larger concentrations relative to lead in some air streams
than others depending on the temperature of the process and exiting
gas. The data should be examined to see if such mechanism-based
expectations are borne out in the available observations. If so, then
some metal HAP to lead ratios could be varied across process streams
(and perhaps across facilities) to reflect the mechanism-based
associations.
(b) In representing the interindividual variability of exposure
factors such as consumption of different kinds of produce and fish, the
analysts should seek data to quantify variability observed on different
time scales than the 1-3 days that are typical for direct dietary
studies. Some downward adjustment clearly needs to be made to calculate
variability over longer time scales from shorter term data. However,
because some dietary preferences are likely to be relatively consistent
characteristics for individual people, it is not reasonable to estimate
long term dietary exposure variability either by simply assuming that
each separate 1- or 3-day period is a random draw from an observed
population distribution of consumption. Some data bearing on the
difference in effective variability in fish consumption inferred for
longer vs. shorter timeframes is reviewed in Hattis et al. (1999).
(c) In Section 4.4 the document should clearly explain the
implications of the assumptions that are being made. For example, the
statement is made on p. 127 that because of data insufficiency, no
analysis of correlation among emission parameters and exposure factors
was undertaken. The statement should be clarified to say that the
correlation could not be undertaken because the data wasn't available
for it.
Charge Question 8. Results Presentation--Does the Agency's document
clearly present and interpret the risk results? Does it provide the
appropriate level of information? Do the figures and tables adequately
present the data? Do the formats provide for a clear understanding of
the material?
Response. As discussed above, the presentation of the basic inputs
and methodology is very far from being adequate to provide a document
that is even transparent enough for a thorough review, let alone a
document that appropriately assess the uncertainty and variability for
decisionmaker and the dependence of the results on key sets of
assumptions. Without documentation of the derivation of the results and
their uncertainties, the results cannot be appropriately conveyed to
decisionmakers and the public. Moreover the neglect of real population
variability in both exposures and risks deprives the reader of
important information that is needed to arrive at risk management
judgments.
reference
Goble, R. and Hattis, D. ``When the Ceteris Aren't Paribus---
Contrasts between Prediction and Experience in the Implementation of
the OSHA Lead Standard in the Secondary Lead Industry,'' Report to the
Office of Technology Assessment, U.S. Congress, by the Center for
Technology, Environment, and Development, Clark University, July, 1995.
R. Goble, D. Hattis, M. Ballew and D. Thurston, ``Implementation of
the Occupational Lead Exposure Standard,'' Report to the Office of
Technology Assessment, Contract No. 233-7040.0, MIT Center for Policy
Alternatives, CPA 83-20, October 1983.
Goble, R. and Hattis, D. ``When the Ceteris Aren't Paribus---
Contrasts between Prediction and Experience in the Implementation of
the OSHA Lead Standard in the Secondary Lead Industry,'' Report to the
Office of Technology Assessment, U.S. Congress, by the Center for
Technology, Environment, and Development, Clark University, July, 1995.
Hattis, D., and Anderson, E. ``What Should Be The Implications Of
Uncertainty, Variability, And Inherent `Biases'/'Conservatism' For Risk
Management Decision Making?'' Risk Analysis, Vol. 19, pp. 95-107
(1999).
Hattis, D., and Minkowitz, W.S. ``Risk Evaluation: Criteria Arising
from Legal Traditions and Experience with Quantitative Risk Assessment
in the United States.'' Environmental Toxicology and Pharmacology, Vol.
2, pp. 103-109, 1996.
Hattis, D. Banati, P., Goble, R., and Burmaster, D. ``Human
Interindividual Variability in Parameters Related to Health Risks, Risk
Analysis, Vol. 19, pp. 705-720, 1999.
__________
Statement of Dr. Michael J. McFarland, Engineering Department, Utah
State University, River Heights, UT
residual risk assessment secondary lead smelter source category
SAB Charge Question No. 1. Are the methods used to estimate
emission rates and the method used to estimate species at the stack
appropriate and clearly described?
initial inhalation risk screening
Findings
The method used to estimate the HAP emission rates involve the use
of several data sets from the Background Information Document from
which the MACT standards were initially derived. The first data set
(Table B.1.1) includes estimate emission rates (in metric tons/year)
for each of the three emission sources including: (1) process stack
emissions (both organic and metal HAPs), (2) process fugitive stack
emissions and (3) fugitive emissions. The second data set (Table B.1.2)
includes ratios of specific organic HAP emissions to total hydrocarbon
emissions from the stacks of three (3) types of secondary lead smelter
furnace types. The final data set includes the median metal specific
HAP to lead ratios (Table B.1.3) as well as the total metal HAP to lead
ratio for each of the three emission sources that include: (1) process
stack emissions, (2) process fugitive stack emissions and (3) fugitive
emissions.
Although Table B.1.3 indicated that the reported data were the
median metal (total and specific) HAP to lead ratios, it is unclear
whether Tables B.1.1 or B.1.2 were also reporting median values or
another statistical measure (e.g., mean or average) of the sampling
data. Moreover, since the purpose of the initial inhalation screening
analysis was to employ a lower tier conservative approach to screen
those HAPs that did not pose a significant human health risk, it would
seem more appropriate to use the upper limit of a confidence interval
(e.g., 95 percent) of the HAP ratios for estimating emission rates
rather than mean (or median) values to estimate inhalation risk. Given
the wide range in HAP ratios found in the data tables, use of an upper
confidence limit would provide greater protection from deletion of
species that may, in fact, represent a significant human health and/or
ecological risk. The same argument can be applied to the use of a mean
or median total HAP emission rate (Table B.1.1) for estimating specific
HAP emission rates. The large range in reported data suggests that a
more defensible risk screening evaluation would be achieved by
selecting an upper limit of a prescribed confidence interval of
emission rates for input into the general inhalation risk model rather
than the use of an average emission rate.
Another concern regarding the inhalation risk model inputs was the
specific management of the acid gas data. Both chlorine
(Cl2) and hydrogen chloride (HCl) emissions were included in
Table B.1.2 and treated as organic HAPs in the emission rate
calculations. The concern with regard to the acid gas data stems not
only from the placing of the inorganic acid gas emissions in the table
for organic HAPs (i.e., Table B.1.2) but, it is also unclear as to
whether the total organic HAP process emission rate data (Table B.1.1)
includes the contribution from the acid gases.
Although there are some concerns regarding the input data quality
for the initial inhalation risk screening, the mathematical equations
used to estimate the specific HAP emission rates are fundamentally
sound. The specific metal HAP emission rates (EHAP) from
each of the three emission sources (i.e., process stack emissions,
process fugitive stack emissions and fugitive emissions) were estimated
by substituting the estimated total metal HAP emission rates (metric
tons/yr) for each emission sources (ETMH-Table B.1.1), the
median metal HAP to lead ratio (RHAP--Table B.1.3) and the
total metal HAP to lead ratio (RTMH-Table B.1.3) into
Equation 1.
EHAP = (ETMH)/
RTMH)(RHAP)
where
EHAP = Individual metal HAP emissions (i.e., antimony);
ETMH = Total metal HEP emissions;
RTMH = Ratio of total metal HAP emissions to lead
emissions;
RHAP = Ratio of individual metal HAP emissions from lead
emissions.
The specific organic HAP emission rate (EVOC) from the
process stack emission source was estimated by substituting the
estimated total hydrocarbon emission rate (metric tons/yr) from Table
B.1.1 (ETHC) and the ratio of specific organic HAP to
hydrocarbon emissions (RVOC-Table B.1.2) into Equation 2.
EVOC = (ETHC)(RVOC)
where
EVOC = Individual organ HAP emissions;
ETHC = Total hydrocarbon emissions;
EVOC = Ratio of individual organic HAP emissions to
total hydrocarbon emissions.
Recommendations
Although the data input descriptions were, in general, well
written, there are several areas where significant improvement could be
made. The specific recommendations for this section of the review
include the following:
The data in Tables, B.1.1 and B.1.2 can be improved by explicitly
stating the statistical measurement parameter being reported.
Consideration should be given to the use of upper confidence limits
(of the HAP ratios) as inputs to the inhalation risk model.
The text should provide greater clarity as to how the acid gas data
are being managed.
To provide clarity in the use of the mathematical relationships,
quantitative examples should be inserted into the text that illustrate
the use of Equations 1 and 2.
An example should be provided (perhaps in an appendix) illustrating
how raw emission data from each emission source (i.e., process stack
emissions, process fugitive stack emissions and fugitive emissions) is
managed to generate final risk numbers.
multipathway analysis
Findings
The method used to estimate emission rates for the multipathway
analysis included the use of compliance reports from stack tests for
specific facilities (i.e., Facilities 2, 3, 4 and 13--Table C.1.1) as
well as the EPA data base developed in the Background Information
Document (BID). The MACT standards require that facilities report, at a
minimum, both the total lead and total hydrocarbon emission rates. For
Facilities 3 and 4, additional compliance testing was conducted that
allowed specific organic and metal HAP emissions to be estimated. These
facility-specific emission estimates were then used to generate
specific emission ratios including: (1) organic HAP to total
hydrocarbon ratio and (2) metal HAP to total lead ratio.
To estimate specific organic HAP emissions for Facility 2, the
organic HAP to total hydrocarbon ratio generated from Facility 3 data
was multiplied by the total hydrocarbon emission rate from Facility 2.
Similarly, to estimate specific organic HAP emissions for Facility 13,
the organic HAP to total hydrocarbon ratio generated from Facility 3
data was multiplied by the total hydrocarbon emission rate from
Facility 13. Since diethylhexyl phthalate and naphthalene were not
measured in Facility 3-stack test, EPA data base information was used
to generate the organic HAP to total hydrocarbon ratio for these
species for Facility 2 and 13.
To estimate specific organic HAP emissions for Facility 3 and 4,
averages from three (3) stack test measurements for each facility were
reported (adjusted for nondetects). Since diethylhexyl phthalate and
naphthalene were not measured in Facility 3-stack test, EPA data base
information was used to generate the organic HAP to total hydrocarbon
ratio for these species. It was not possible to estimate diethylhexyl
phthalate and naphthalene emissions in Facility 4 since the MACT
standards do not require total hydrocarbon measurements for reverbatory
furnaces.
To estimate specific metal HAPs for process emissions for Facility
2, the metal HAP to total lead ratio developed for Facility 3 was
multiplied by the lead emission rate found in the Facility 2 compliance
report. Similarly, for Facility 13, the metal HAP to total lead ratio
developed for Facility 3 was multiplied by the lead emission rate found
in the Facility 13 compliance report. Facilities 3 and 4 reported
specific metal HAP emission rates for process emissions. It should be
noted that Facility 3 did not test for antimony and Facility 4 did not
test for manganese or mercury. The emissions of these metal species
were estimated using EPA data base information to develop the metal to
lead ratio, which was then multiplied by the lead emissionrate from the
facility compliance report.
To estimate specific metal HAPs for process fugitive emissions for
Facility 2, the average of the fugitive metal HAP emissions to total
lead ratio developed for Facility 3 and 4 was multiplied by the lead
emission rate found in the Facility 2 compliance report. Similarly, for
Facility 13, the average of the fugitive metal HAP emissions to total
lead ratio developed for Facility 3 and 4 was multiplied by the lead
emission rate found in the Facility 13 compliance report. Facilities 3
and 4 reported specific metal HAP emission rates for fugitive process
emissions. Finally, the Background Information Document (BID) estimates
for fugitive emissions used in the initial inhalation screening were
employed in the multipathway analysis.
With regard to metal speciation, 99 percent of the chromium
emissions is assumed to be Chrome (III). This assumption was based on
one furnace measurement and the fact that the secondary lead smelters
operate under a reducing environment. For mercury speciation, it was
assumed that all of the evaluated mercury was in the form of divalent
particulate mercury (HgO).
Although the multipathway analysis employs site-specific data, it
is unclear whether the comparability of the data been evaluated. In
other words, in many cases, EPA data base information is used in
conjunction with site specific data to generate specific HAP emission
rates with no verification that the data sets contain elements of
equivalent or similar quality. The absence of data quality evaluation
leads to several fundamental questions that are summarized as follows:
What criteria were used to determine when Facility 3 data should be
used for estimating organic HAP emissions from Facility 2 and 13 versus
EPA data base information?
Are emission estimates provided in Table C.1.1 averages, median or
upper limits of a confidence interval?
How many samples comprise the emission values reported in Table
C.1.1? Can ranges or standard deviations be given?
Do the State compliance stack permits specify the number of samples
to be taken? In other words, are all data of a known quality?
Descriptions of Facility 3 and 4 stack tests indicate that three
stack test were conducted to estimate organic HAP emissions. Does this
mean three samples?
It is unclear as to why the average of Facility 3 and 4 process
fugitive metal HAP emissions were used to derive a specific metal HAP
to total lead ratio for Facility 2 and 13.
Recommendations
Since HAP emission rates were generated using various facility data
sets as well as the EPA data base, the most important general
recommendation is that the Agency verifies the comparability of the
data.In other words, use of data of varying quality in the risk
assessment models would generate final risk numbers of questionable
value. Therefore, the quality of each data set should be compared and
documented prior to having its elements used in the risk assessment.
Second, since there is no specific protocol employed for estimating the
HAP emissions from each of the four facilities, it is strongly
recommended that quantitative examples be inserted into the text that
illustrate each unique approach. Finally, additional recommendations
regarding data inputs to the multipathway model include the following:
a. Specify the type of statistical measurement being reported in
Table C.1.1 (i.e., means, median, upper confidence limits, etc.).
b. Specify the number of samples that comprise the emission values
reported in Table C.1.1 and provide both ranges and standard
deviations.
c. Provide an explanation as to why the average of Facility 3 and 4
process fugitive metal HAP emissions were used to derive a specific
metal HAP to total lead ratio for Facility 2 and 13 rather than some
other statistical measurement.
______
Statement of Dr. Paulette Middleton, RAND Center for Environmental
Sciences & Policy, Boulder, CO
1. links to other key epa activities dealing with haps
Other EPA activities that have direct bearing on the residual risk
assessments should be noted in the document. These activities
demonstrate that EPA is actively improving on the current framework.
While the current approaches used in the document under review here are
acceptable in the current timeframe, many of their shortcomings may be
addressed as a result of these other ongoing efforts. Acknowledgment of
this could be done upfront in the introduction where discussion of
model appropriateness and future assessments are mentioned. They also
could be placed at the end of the report where next steps are sited and
where it is noted that SAB comments will be considered in next steps.
2. trim
In particular, it should be noted that EPA/OAQPS is developing TRIM
as a flexible, state-of-the-art system for evaluating multimedia
chemical fate, transport, exposure and risk of HAPs. The recent SAB/
Environmental Models Subcommittee review of this effort found it to be
effective and innovative and outlined a number of recommendations for
improvement. When TRIM becomes available, it should provide an
improvement over the modeling framework used in the current report.
3. sab/epa workshops on the benefits of reductions in exposure to
hazardous air pollutants
As stated in the description of these up and coming workshops,
``HAPs have been the focus of a number of EPA regulatory actions, which
have resulted in significant reductions in emissions of HAPs. EPA has
been unable to adequately assess the economic benefits associated with
health improvements from these HAP reductions due to a lack of best
estimate dose-response functions for health endpoints associated with
exposure to HAPs and also due to a lack of adequate air quality and
exposure models for HAPs. EPA is conducting two workshops to develop a
proposed methodology to generate estimates of the quantified and
monetized benefits of reductions in exposure to HAPs. The first
workshop will focus on developing best estimates of dose-response
functions that relate changes in HAP exposure to changes in health
outcomes. The second workshop will focus on (1) integrating these dose-
response functions with appropriate models of HAP concentrations and
human exposure and (2) translating these into economic benefits that
would estimate changes in health risks resulting from regulations that
reduce HAP emissions.'' The results of these workshop discussions, in
particular the reviews of models and methods, could well provide
additional valuable input to this ongoing evaluation of the residual
risk review and development of next steps.
4. questions and comments on the current study
a. Missing HAPs
Have all of the potential important HAPs been included in the
screening analysis? Can understanding of the processes be used to
better substantiate the list of HAPs considered for screening?
Why are the acid gases not included in the analysis?
Organics are not considered beyond the screening. Can this
screening result be better substantiated?
b. Emission rates
The development of emission rates for individual HAPs needs to be
more clearly described. Here are some outstanding questions that need
to be answered before providing a reasonable evaluation of
appropriateness of the emissions estimates used in the modeling (both
screening and multi-pathway).
What exactly was measured at the representative sites and how were
the measurements done? How valid are the extrapolations of
representative measurements to annual averages? How valid are the
extrapolations to other facilities?
Are the processes leading to the emissions fairly constant
throughout the year? How variable are the fugitive emissions at a given
site?
5. modeling
The model choices have been defended reasonably well. However, as
noted above, improvements are needed and may be forthcoming with TRIM.
Models seem to have been applied appropriately. However, several
concerns are noted below regarding the assumptions in the modeling that
could have an impact on the overall analyses.
6. screening
There needs to be more convincing discussion of the
representativeness of the building and meteorology general parameters
chosen.
Are the facilities being considered reasonably represented by the
general building and stack configurations assumed? Stack height and
building heights are particularly important variables.
Is the meteorology of the sites being screened adequately
represented by the standard worst case meteorology? Wind speeds and
directions relative to the selected receptor sites are particularly
important variables.
7. multi-pathway
Again, are the assumptions about standard building parameters
reasonable? The assumptions about building parameters are retained in
the multi-pathway analysis. This is probably reasonable provided the
actual facilities are similar in construction.
What particle parameters and sizes are assumed in the modeling?
This is very important to clarify since the ISCST3 does show different
results for assumptions about larger particle sizes. If all of the
particles considered are assumed to be less than 10 microns, then I
doubt there is any difference in deposition and concentration patterns
from those for the gases. This needs to be clarified since the
exposures are sensitive to assumptions about particle size and particle
versus gas.
8. receptors
A suggestion. The ISCST3 can produce patterns of concentrations and
deposition at regular distances from the source. It might be helpful to
provide these patterns as well as analysis at specific receptors.
Patterns help provide an assessment of where risks might be important
in the future. Is this type of analysis thought to be beneficial to the
overall residual risk assessment?
9. model/measurement comparisons
The results presented seem to be reasonable for the air models.
However, the other comparisons are difficult to understand and are
being discounted. The way that these comparison are being presented
detracts from the work and tends to make one more skeptical of the
findings.
10. uncertainty
It would be helpful to even more explicitly tie uncertainties to
well-defined next steps.
Statement of Dr. George E. Taylor, Biology Department, George Mason
University, Fairfax, VA
a case study residual risk assessment secondary lead smelter
source category
The SAB review of the draft Residual Risk Report to Congress was a
challenge in light of the report being framed in very general way. In
my participation of that review, I was uneasy about the review solely
because I was unable to see the trajectory for the analysis in a
quantitative sense.
The Secondary Lead Smelter Source Category analysis is a giant step
forward and helps me be more confident that the analyses will be
quantitatively based and linked to the literature on human health and
ecology. The Agency is commended for pursuing that tack.
There are a number of general issues that are of concern however in
the draft document and the presentations at the meeting. These general
issues are outlined. Collectively, these suggest to me that the current
draft is well short of being scientifically defensible with respect to
natural resources and ecology.
1. Attention to Ecology and Natural Resources
The attention to ecology and natural resources was a major concern
in the Residual Risk Report to Congress, and I strongly encouraged the
Agency to place ecology at parity with human health in this effort.
Some assurances were made in that review exercise that ecology would be
given more attention.
In the case of the Secondary Smelters, the case for ecology and
natural resources is again diminished by the Agency. The effort is
clearly well behind the analysis being conducted for human health and
is not at a stage where this reviewer can be comfortable with a
positive review. In short, while we have made some progress, there is
insufficient analysis conducted to meet the legal mandate of the CAA.
This issue is a major one and warrants high visibility. My
recommendation is for the committee to exhort the Agency to be more
forthcoming with resources in order to get the task done in a
scientifically sound manner.
2. Not a Risk Assessment But a Risk/Hazard Characterization
The title of the Agency's report is A Case Study Residual Risk
Assessment: Secondary Lead Smelter Source Category. Risk
Characterization. Following the original review of the draft Residual
Risk Report to Congress, this reviewer was expecting an analysis that
was more nearly a risk assessment. What was presented was a hazard
characterization for ecology and natural resources, and the analysis
was preliminary at best. Moreover, the Agency stated that no further
work toward a risk assessment would be conducted for ecology and
natural resources.
As a consequence, the current analysis does not meet the legal
mandate of the CAA.
3. If this is the final product for this source category. . .
Because this report establishes a methodology for analyzing 179
source categories, it is very important that this report be done right.
In light of the Agency's commitment to a preliminary hazard
characterization in lieu of what is the legal mandate, I am concerned
that this document will establish a precedent for all subsequent
analyses so that ecology and natural resources are poorly addressed. As
it now stands, the methodology produces a high number of false
positives and fails to incorporate some pathways and receptors that are
the most sensitive ones in an ecosystem with respect to persistent and
bioacceumulated chemicals.
The proposed methodology is not likely to be of value in assessing
the residual risk to ecology and natural resources and is likely to
leave the risk manger with a formidable problem in handling the
purported risks.
4. Linkage to Risk Manager
The shortcomings of the current report are presented above and are
worthy of attention. Above and beyond these shortcomings is the linkage
of the risk assessment to the task of the risk manager. There is no
discussion of how the risk manager is likely to use this assessment.
It is recommended that a framework for the risk management be made
a part of this report. The same recommendation was made for the
previous report (Residual Risk Report to Congress) by the SAB.
5. Conclusion That the Analysis is Conservative
This assertion is stated throughout the report, and I am not in
full agreement with that distinction with respect to ecology and
natural resources. My rationale is twofold. Most importantly, the
omission of fish eating birds (top carnivores) removes one of the top
predators in terrestrial/aquatic systems and one of the receptors that
is highly valued (charismatic megafauna). In my analysis of the report,
mercury would easily have been identified as a risk had this trophic
level been included; it probably would have been the dominant risk. The
argument that predatory fish are included does not suffice since
predatory birds consume predatory fish, so there is an additional
trophic level for bioaccumulation. The argument that data do not exist
to evaluate this receptor is not accurate.
The second point is more tangential. The analysis for ecology
identified a number of HAPs with concern in the screening exercise.
Most, if not all, of these are likely to be ``false positives''. For
example, antimony is screened as a risk, but I have never read a paper
dealing with ecotoxicology to plants of antimony. The citation for the
benchmark is an old paper published in an agricultural setting. The
point is the false positives are almost to the point of being ``silly''
and can be easily discounted by the risk manager. This ``silliness''
might establish a precedent for ecology and natural resources that
would permeate all 179 analyses.
I would much prefer to see a screening exercise that covers the
potential serious risks (e.g., Bioaccumulated HAPs in top carnivores)
than marginal risks, and I think that is the objective of the legal
mandate.
6. HAPs That are Persistent and Bioaccumulated
The tenet is stated that any HAPs that is persistent and
Bioaccumulated is automatically carried to the next level (multipathway
not refined analysis?). I think those terms are confusing (e.g., if it
is Bioaccumulated, by definition it is persistent; some persistent HAPs
may not be Bioaccumulated). I am not certain what this statement means.
Most HAPs by definition are persistent. Lead, Ni, Hg, etc. . . .
are elements and by definition are persistent. Most of the HAPs are
also accumulated to some extent simply because many are lipophilic
either as elements or in the complexes they form. So, there must be a
threshold for bioaccumulation. Does that have to be a trophic
enhancement factor of 2?
7. Background Concentrations
This issue was raised in the previous review and I encourage the
Agency to re-think its position. While there may be some rationale for
assuming a zero background concentration in the screening exercise,
there are some major liabilities even at this level for pursuing this
line of reasoning.
Even more difficult is the next level of analysis in which
exposure-response functions might be generated. Given that many of the
HAPs are elements and are common geochemical constituents in the crust,
not addressing this issue is likely to undercut the conclusions
significantly from a scientific basis.
specific comments
This review supplements the forgoing analysis, which is more
general. The comments herein are more specific and either supportive of
the above or individualistic.
1. More refined analysis. The argument is presented often about the
next iteration, which is a refined analysis. The structure and
refinements to be done in that analysis are not presented. Is this to
be a full risk assessment?
2. Screening for chronic effects protects for acute effects. While
I can appreciate why shortcuts are used, I am not certain that this
position is true. I can think of several cases where chronic exposures
would not protect against acute exposures. For example, if you had a
fugitive emission of a toxic chemical with a high 1 hour exposure, over
the course of the season that exposure would not be significant but may
very well compromise some receptors (e.g., radiochemicals, ozone). Can
you provide a citation that supports the position?
3. Background concentration. This issue was raised in the previous
review, and I am not in favor of the position being taken in the
report. While the screening exercise may opt to assume that the
background concentration is zero, this is NOT a conservative decision.
In fact, it may significantly negate many HAPs (particularly those that
are elements common in the earth's crust) from ever accumulating enough
to exceed a threshold. I recommend that the Agency re-consider its
position on background exposures, particularly as one moves on to more
refined analyses. From my perspective, this omission negates the
Agency's position that the analysis is conservative. Moreover, I do not
think you can conduct a more refined analysis without including a
background exposure for either human health or ecology. But, in the
case of the latter, it is clearly critical.
4. Modifications to the multipathway model. It is noted that the
analysis used the multipathway model in the Mercury Report to Congress
for this modeling effort but that the model was modified on a HAPs-
specific basis. Those modifications are important to State since they
could underpin the analysis.
5. Dispersion modeling. The report uses a dispersion model
(Gaussian) to handle the offsite transport of HAPs. The guts of the
model are not presented and key aspects are missing that might help
skeptics relate to the code. Is deposition velocity (Vg) the operative
parameters for driving deposition? If so, what nonlinear relationship
is being used? Is particle size a part of the emission data? If not,
then Vg cannot be used.
6. Figure 3.1 is missing but discussed in the text.
7. Plant Characteristics. Plants appear to be one of the critical
parts of the model as the exposure to humans is preceded by deposition
to leafy vegetable. This part of the code needs to be reviewed for such
features as leaf area index, Vg, seasonality of phenology, yield,
foliar leaching, etc. My suspicion is that none of these factors are
part of the model, so it is unclear that the model handles the
atmosphere-leaf transfer very well.
8. Figure 3.3. It is customary in compartment model diagrams to
show compartments/state variables as boxes and transfers as ovals or
some other geometric shape. They mean very different things. Also, is
the half-life (T\1/2\) part of the model for HAPs? If so, a table of
T\1/2\'s should be published. This is an important parameter.
9. The argument is presented that the mercury concentration in fish
is a function of the mercury concentration in water. Is that true? I do
not see how this could be coded into an aquatic model with multiple
trophic levels? The mercury concentration in water must be processed
through several intervening trophic levels before it gets to fish and
thereafter it is bioaccumulated as a function of the trophic level.
10. The summary for all sections is not a summary. The summaries
relate the methodology but not the summary of using the mythology for
this exercise on lead smelters.
11. What are the endpoints in ecology and natural resources? In
human health it is the farmer and his family. Clearly State the
endpoints for this hazard characterization.
12. It is stated that the structure and function of the ecosystems
is an endpoint. I have difficulty with that position.
13. It is stated that rare and endangered species are an endpoint.
Again, I have trouble with that position.
14. Are receptors the same as assessment endpoints?
15. Why are carnivorous terrestrial wildlife omitted? These are
likely to be the ``charismatic megafauna'' of most interest and the
ones at greatest risk form HAPs that are bioaccumulated.
16. EC50 derivation. The argument is presented to derive some
benchmarks from EC50's by dividing by a factor of 10. I am not certain
that is justified. I would prefer to simply leave the benchmarks as
stated in the literature rather than deriving some. This will eliminate
a number of false positives and will help add credibility.
17. Summing HQ's. As noted above, this approach needs to be done
with extreme caution.
18. Bioaccumulation. It is stated that bioaccumulation is assumed
to be 100 percent. I am not sure what that means. Does that mean 100
percent of the HAP in the system is bioaccumulated to the next trophic
level? If so, what BAF is used?
19. All chemicals without data are analyzed further. This is
difficult to imagine. But, if there are insufficient data to conduct a
screening analysis, how could there possibly be enough data to do a
more refined analysis?
20. Fugitive Emissions. While I understand that fugitive emissions
can be important, I am skeptical of the methodology that shows the
entire assessment being driven by fugitive emissions. From my knowledge
of ecology and human health, that simply does not compute.
21. False positives for ecology. This is where I think the
methodology suffers, and I recommend that some remediation is in order.
The ecology risk section concludes that several HAPs--antimony,
chromium, and nickel--are a significant enough risk to warrant further
study. I am not aware of any report for antimony in plants that would
warrant that conclusion and probably the same for chromium and lead and
nickel. The creation of many false positions that are unrealistic will
be self defeating in the long run.
22. False negatives for ecology. In contrast to the above concern,
there are some HAPs that are missing for methodological reasons. The
most notable is mercury, which can be traced to the absence of top
carnivores in terrestrial ecosystems.
23. Appendix F, Table F.2. The equation for calculating dry
deposition simply does not work as portrayed. The units do not cancel
out to arrive at the correct units.
24. Appendix E. The hazards with fugitive emissions are an order of
magnitude higher than those without fugitive emissions. This seems
inordinately high.
25. Distance for dispersion. The distance used for dispersion and
assessment needs to be defined. Clearly it is not the distance traveled
by the HAPs after emission, which for some of these (e.g., mercury) is
global.
26. Air stagnation events. How are air stagnation events handled in
the model?
27. Criteria pollutants. While I understand some of the legal
mandate for this analysis, I suspect that some of the most significant
residual risk from these categories will be the impact of the criteria
pollutants, notably ozone and PM2.5. This liability is best
presented up front so the caveats are well articulated.
__________
Statement of Dr. Rae Zimmerman, Robert Wagner Graduate School of Public
Service, New York University, New York, NY
basis for case study selection
The rationale for the choice of secondary lead smelters as a case
that will become a prototype is only briefly described and should be
expanded. Why is it significant and prototypical? Is it like other
industrial emission sources?
The change in capacity or use of these smelters might be one reason
for their being a significant case. The discussion on p. 5 alludes to a
reduction in the number of lead smelters nationwide in 1999 over 1993-
1994 levels. Capacity is really key, however. Has the capacity of the
remaining smelters increased? Is the need for them changing, i.e., what
is the quantity of lead-acid batteries needing recycling?
One very strong reason for its selection is that it is central to
the debate over electric cars (see debate in Science, 1995). The
contribution of lead smelters to air pollution in the course of
recycling lead-acid batteries is part of the overall assessment of the
relative environmental impact of electric cars over the conventional
automobile. Thus, the relative risk associated with secondary lead
smelters addresses a much broader health debate.
methodological issues
A number of methodological issues need greater explanation or some
references to justify methodological approaches and choices.
a. p. 6--the expediency of using a surrogate standard for all
metals is clear, but why was lead selected?
b. p. 9--what is the justification for using inhalation analysis
for all HAPs rather than the ingestion route also, e.g., via soil
deposition and subsequent entrainment in exposure areas? p. 14 also
notes that inhalation pathway is the most important route of exposure,
which needs a short explanation.
c. Decisions are made throughout the analysis, and should be
explained. For example:
d. p. 9 How is the subset of facilities selected--just high
emission rate rather than mix of HAPs? In other words a facility with a
high emission rate may have low concentrations of HAPs.
e. p. 10 Receptor locations chosen as the point of maximum air
concentration--was this regardless of the number and type of HAPs?
f. p. 10 How were the three HAPs and three pathways selected for
the variability and uncertainty analyses?
g. Is there any way of identifying which of the HAPs present in the
emission stream are likely to react with one another to increase or
reduce residual risk?
h. The rationale behind the use of very numerous assumptions/
defaults at any given point in the assessment is difficult to evaluate,
e.g., p. 24, 32. On p. 24, for example, there are numerous simplifying
assumptions for the inhalation screening analysis.
How do these assumptions interact with one another and affect the
results?
i. In areas where information is not known, can't the Agency
undertake some scenario building to at least identify some of the
boundaries? For example:
(1) Geographic differences in the location of the smelters and the
effects of this variation on exposure are not included, but need to be
factored in somehow into the analyses. For example, p. 24-25 the
building downwash or terrain options for SCREEN3 were not used because
site specific information was not available. This is important,
however, since the report specifically identifies that the use of such
options can result in higher values for air pollutants. What about
using locational scenarios?
(2) Where information on d/r for HAPs was not available the HAPs
were excluded from the analysis (p. 33)--Does the uncertainty analysis
at least include the fact that ``HAPs for which quantitative d/r
assessments are not available'' were excluded from the quantitative
analysis?
j. p. 30 The technique for aggregating cancer risks is additivity.
The drawbacks of this yet the need should be clearly stated, as well as
how additivity is likely to affect the results.
______
APPENDIX B
a more detailed description of the sab process
The SAB Staff recruited Dr. Philip Hopke, Chair of the Chemistry
Department at Clarkson University, to serve as Chair of the
Subcommittee. Working with the Chair, other SAB Members and
Consultants, Agency Staff, and submissions from the American Industrial
Health Council (AIHC) and the Natural Resources Defense Council (NRDC),
the SAB Staff compiled a list of over 30 scientists and engineers who
were subsequently surveyed for their interest in and availability for
participating in the review. The Chair and SAB Staff made the final
selections for membership on the Subcommittee and assigned different
members lead and associate responsibilities for each of the Charge
Elements.
The Agency transmitted review materials to the Subcommittee members
in late January. In mid-February SAB Staff convened a conference call
with Agency staff to identify gaps in the information sent to the
Subcommittee and to identify areas that the Agency should be prepared
to clarify at the face-to-face meeting.
In addition, public comments were received from the following
parties and distributed to the Subcommittee Members before the meeting:
a. Association of Battery Recyclers and the Lead Industries
Association: Robert Steinsurtzel and Michael Wigmore--Swidler Berlin
Shereff Friedman (Counsel for Association of Battery Recyclers), Jane
Luxton and Cynthia A.M. Stroman--King and Spalding (Counsel for Lead
Industries Association, Inc.), Dr. Teresa S. Bowers--Gradient
Corporation, Russell S. Kemp--Lake Engineering.
b. Cambridge Environmental Inc: Dr. Edmund Crouch and Dr. Stephen
Zemba.
c. Indiana Department of Environmental Management: Mr. Michael
Brooks
d. Residual Risk Coalition: Dr. Elizabeth Anderson--Sciences
International, Inc.
e. Sanders Lead Company, Inc.: Mr. Billy Nichols, Dames & Moore.
On March 1-2, 2000, the Subcommittee convened in the Main
Auditorium of Environmental Research Center at the USEPA laboratory in
Research Triangle Park, NC. Minutes of the meeting are available. Each
member of the Subcommittee submitted written comments on the Charge
questions for which he/she had lead responsibility. Two members of the
public (Dr. Elizabeth Anderson and Dr. Teresa Bowers, see a and d
above) provided comments on the technical issues under discussion.
Following a full day of discussion, Subcommittee members drafted and
reviewed responses to the Charge questions.
The Subcommittee members were given the opportunity to refine their
pre-meeting comments for their inclusion in the Appendix A to the
Advisory. These written materials formed the basis of this Subcommittee
Advisory that was drafted by the Chair and the SAB Staff and
subsequently modified/approved by the Subcommittee. [An SAB
``Advisory'' is a term-of-art used to denote review of an Agency
document that is still undergoing development, in contrast to an SAB
``Review'' of a final Agency product.] The Subcommittee-approved draft
was sent to the SAB Executive Committee (EC) for action during a
publicly accessible conference call on May 1, 2000. At that meeting the
EC approved the Advisory, subject to final approval by designated
vettors, Dr. Kenneth Cummins and Dr. Linda Greer.
______
APPENDIX C
Glossary
------------------------------------------------------------------------
------------------------------------------------------------------------
AEI....................................... Average exposed individual
ATSDR..................................... Agency for Toxic Substances
and Disease Registry
BID....................................... Background Information
Document
CaIEPA.................................... California Environmental
Protection Agency
CAAA...................................... Clean Air Acts Amendments of
1990
CDC....................................... Centers for Disease Control
and Prevention
CRARM..................................... Commission on Risk
Assessment and Risk
Management
HAPs...................................... Hazardous air pollutants
HEAST..................................... Health Effects Assessment
Summary Tables
HI........................................ Hazard index
HQ........................................ Hazard quotient
IEM-2M.................................... Indirect Exposure
Methodology
IRIS...................................... Integrated Risk Information
System
ISCST3.................................... Industrial Source Complex
Short Term model
MACT...................................... Maximum achievable control
technology
MEI....................................... Maximum exposed individual
MIR....................................... Maximum individual risk
NAAQS..................................... National Ambient Air Quality
Standard
NATA...................................... National Air Toxics
Assessment
NESHAP.................................... National Emission Standards
for Hazardous Air
Pollutants
NRC....................................... National Research Council
OAQPS..................................... Office Air Quality Planning
and Standards
PAHs...................................... Polyaromatic hydrocarbons
QSAR...................................... Quantitative Structure-
Activity Relationships
PBTs...................................... Persistent bioaccumulative
toxicants
RfD....................................... Reference Dose
RTC....................................... Agency's 1998 Report to
Congress
SAB....................................... Science Advisory Board
TRIM...................................... Total Risk Integration Model
TRVs...................................... Toxicity Reference Values
U&V....................................... Uncertainty and variability
USEPA..................................... United States Environmental
Protection Agency
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