D.C.
October 25, 2004
EPA-SAB-05-002
Honorable Michael O. Leavitt
Administrator
United States Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Subject: EPA's Air Toxics Research Strategy and Air Toxics Multi-Year Plan -
A Review by the Air Toxics Research Strategy and Multi-Year Plan Panel of the
EPA Science Advisory Board
Dear Governor Leavitt:
Air Toxics are air pollutants that may pose a risk to human health or the environment.
Hazardous air pollutants (HAPs) refer to the 188 air toxics that are subjected to regulations under
section 112(b) of the Clean Air Act (CAA). The EPA Office of Research and Development
(ORD), in consultation with the Office of Air and Radiation (OAR), developed an Air Toxics
Research Strategy (ATRS) and an Air Toxics Multi-Year Plan (MYP) to help focus and set
research priorities. The ATRS identifies air toxics research needs, while the MYP presents
ORD's plan for addressing those needs in the 2003-2010 timeframe. This research provides
scientific information and models to better understand the risks of air toxics and to help manage
these risks.
An EPA Science Advisory Board (SAB) Review Panel was convened to review the
Research Strategy and Multi-Year Plan. The Panel responded to five specific charge questions
related to the ATRS, and four charge questions concerning the MYP. The Panel's review of
these documents was significantly aided by interactive presentations and discussions with Office
of Research and Development during its July 23-24, 2003 meeting. Detailed responses to each
charge question are included in the Panel's report. The following are the Panel's key findings
and recommendations:
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o The Panel commends the Agency for its effort in developing the ATRS and MYP. Each
document is well organized, logical, and of an appropriate level of detail. ORD is also
commended for presenting the annual performance goals (APGs) and annual performance
measures (APMs) in the MYP in terms of measurable outcomes and outputs for which
the Agency will be accountable.
o The Panel found that there is a poor linkage between the ATRS and MYP because they
follow two different and disconnected planning frameworks. The ATRS is built around
five strategic principles, seven key research questions and many sub-questions. The
MYP is organized around two long-term goals, APGs and APMs. The Panel is also
concerned that the MYP's two long-term goals are too broad to provide useful guidance
in setting research priorities. In addition, there is a need for both of these documents to
clearly show their relationship with research strategies and multi-year plans in other EPA
research program areas.
o EPA funding for air toxics research is approximately $20 M annually, of which
approximately 20 percent is used for administration. The panel believes that this level of
funding is inadequate, given the magnitude of research needs in this area, and the
administrative costs are excessive. With the limited available funding, the ATRS cannot
be accomplished without significant support from other EPA research programs. The
Agency must be willing to reprogram funds among laboratories and centers as the need
arises. In addition, the Panel underscores the need for EPA to articulate how it will
coordinate and collaborate with other external research organizations.
o The Panel recommends that EPA set research priorities through a transparent and open
process that emphasizes those HAPs that pose the greatest health risks to exposed human
populations, based on exposure levels, size of the exposed population, and the severity of
potential health effects. Although the ATRS lays out five strategic principles to guide
and identify priority research activities, the MYP does not describe how these principles
are applied in setting air toxics research priorities. In setting priorities, the Panel
recommends that EPA use a tiered screening approach that progressively incorporates
physicochemical, exposure, and biological data to identify chemicals that warrant
additional research.
o The Agency utilized the National Research Council's 1983 (NRC 1983) risk assessment
and risk management paradigm in developing its key scientific questions and strategic
principles in the ATRS and long-term goals in the MYP. The SAB believes that EPA
should employ an updated paradigm that emphasizes an integrated approach to the
framing of the environmental problem, the technical risk assessment and risk
characterization, the consideration of environmental decision options, and stakeholder
involvement.
o The Panel noted that neither the ATRS nor the MYP addresses risk communication
research. This is a significant omission. The Panel also identified several areas where
greater research emphasis is needed, including:
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- Improved ambient analytical methods for air toxics for use by EPA, States, and
Tribes in improving monitoring networks and for validating models used to predict
ambient concentrations of air toxics;
- Improved methods to characterize uncertainty and variability in exposure-response
relationships and population distributions of exposure; and
Studies of the risks associated with HAP mixtures in addition to single compounds.
o EPA should provide more opportunities for the external scientific community to
contribute input on its air toxics research.
The Panel appreciates the opportunity to review these documents and feels that periodic
involvement by a Science Advisory Board committee to review the strategy and annual plan
components and to provide advice and feedback would be helpful to the Agency.
Sincerely,
/Signed/
Dr. William Glaze, Chair
US EPA Science Advisory Board
/Signed/
Dr. Frederick J. Miller, Chair
Air Toxics Research Strategy/
Multi-Year Plan Panel
US EPA Science Advisory Board
in
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NOTICE
This report has been written as part of the activities of the EPA Science Advisory Board,
a public advisory committee 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.
Reports of the EPA Science Advisory Board are posted on the EPA website at:
http://www.epa.gov/sab.
IV
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U.S. Environmental Protection Agency
Science Advisory Board
Air Toxics Research Strategy/Multi-Year Plan Panel*
CHAIR
Dr. Frederick J. Miller, CUT Centers for Health Research, Research Triangle Park, NC
Also Member: Clean Air Scientific Advisory Committee
MEMBERS
Dr. John Balbus, Environmental Defense, Washington, DC
Dr. Joseph Helble, University of Connecticut, Storrs, CT
Dr. Rogene Henderson, Lovelace Respiratory Research Institute, Albuquerque, NM
Dr. Keri Hornbuckle, University of Iowa, Iowa City, IA
Dr. Petros Koutrakis, Harvard University, Boston, MA
Dr. Leonard Levin, Electric Power Research Institute, Palo Alto, CA
Dr. Morton Lippmann, New York University School of Medicine, Tuxedo, NY
Dr. Randall Manning, State of Georgia, Athens, GA
Mr. Mark McMillan, Colorado Department of Public Health and Environment, Denver, CO
Dr. Thomas Overcamp, Clemson University, Anderson, SC
Dr. Lauren Zeise, California Environmental Protection Agency, Oakland, CA
SCIENCE ADVISORY BOARD STAFF
Dr. James Rowe, Designated Federal Officer, Washington, DC
Mr. Joseph M. Greenblott, Designated Federal Officer, Washington, DC
' Members of this SAB Panel consist of:
a. SAB Members: Experts appointed by the Administrator to serve on one of the SAB Standing
Committees.
b. SAB Consultants: Experts appointed by the SAB Staff Director to a one-year term to serve on ad hoc
Panels formed to address a particular issue.
v
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U.S. Environmental Protection Agency
Science Advisory Board
CHAIR
Dr. William H. Glaze, Oregon Health & Science University, Beaverton, OR
VICE CHAIR
Dr. Domenico Grasso, Smith College, Northampton, MA
MEMBERS
Dr. Gregory Biddinger, Exxon Mobil Refining and Supply Company, Fairfax, VA
Dr. James Bus, The Dow Chemical Company, Midland, MI
Dr. Trudy Ann Cameron, University of Oregon, Eugene, OR
Also Member: COUNCIL
Dr. Deborah Cory-Slechta, Rutgers University, Piscataway, NJ
Dr. Maureen L. Cropper, The World Bank, Washington, DC
Dr. Kenneth Cummins, Humboldt State University, Arcata, CA
Dr. Virginia Dale, Oak Ridge National Laboratory, Oak Ridge, TN
Dr. Baruch Fischhoff, Carnegie Mellon University, Pittsburgh, PA
Dr. A. Myrick Freeman, Bowdoin College, Brunswick, ME
Dr. James Galloway, University of Virginia, Charlottesville, VA
Dr. Linda Greer, Natural Resources Defense Council, Washington, DC
Dr. Philip Hopke, Clarkson University, Potsdam, NY
Also Member: CASAC
Dr. James H. Johnson, Howard University, Washington, DC
Dr. Meryl Karol, University of Pittsburgh, Pittsburgh, PA
Dr. Roger E. Kasperson, Stockholm Environment Institute, Stockholm,
Dr. Catherine Kling, Iowa State University, Ames, IA
Dr. George Lambert, Robert Wood Johnson Medical School/ University of Medicine and
Dentistry of New Jersey, Piscataway, NJ
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Dr. Jill Lipoti, New Jersey Department of Environmental Protection, Trenton, NJ
Dr. Genevieve Matanoski, Johns Hopkins University, Baltimore, MD
Dr. Michael J. McFarland, Utah State University, River Heights, UT
Dr. M. Granger Morgan, Carnegie Mellon University, Pittsburgh, PA
Dr. Rebecca Parkin, The George Washington University, Washington, DC
Dr. David Rejeski, Woodrow Wilson International Center for Scholars, Washington, DC
Dr. Kristin Shrader-Frechette, University of Notre Dame, Notre Dame, IN
Dr. William H. Smith, Yale University, Center Harbor, NH
Dr. Deborah Swackhamer, University of Minnesota, Minneapolis, MN
Dr. Thomas Theis, University of Illinois at Chicago, Chicago, IL
Dr. Valerie Thomas, Princeton University, Princeton, NJ
Dr. R. Rhodes Trussell, Trussell Technologies, Inc., Pasadena, CA
Dr. Robert Twiss, University of California-Berkeley, Ross, CA
Dr. Lauren Zeise, California Environmental Protection Agency, Oakland, CA
SCIENCE ADVISORY BOARD STAFF
Mr. Thomas Miller, Designated Federal Officer, Washington, DC
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Table of Contents
Air Toxics Research Strategy/Multi-Year Plan Panel v
Science Advisory Board vi
Introduction 1
General Comments 1
Response to the Charge Questions 2
Charge Question 1
la. Does the research strategy provide a sufficient regulatory and research context? 2
Ib. Is it on target in identifying and addressing the expected research needs of the air toxics
regulatory program? 2
Ic. Is the primary purpose of the ATRS (of improving the science underlying the NAT A
Program) appropriate? 3
Charge Question 2
Do the summary key questions and research needs comprehensively address the important
research that should be undertaken, given the scope of the ATRS? 3
Charge Question 3
Are all relevant discipline areas, e.g., emissions, exposure assessment, health effects, risk
characterization, and risk management, addressed at an appropriate and consistent level of
detail, thereby presenting a unified perspective? 6
Charge Question 4
4a. Are the strategic principles listed in Chapter 2 appropriate? 7
4b. Do they facilitate effective decision making for prioritizing future air toxics research? 7
Charge Question 5
5a. Is the draft ATRS approach of grouping air toxics (Strategic Principle #1), first by
chemical characteristics and then by regulatory need, appropriate, and what other
approaches might be explored to efficiently group air toxics? 8
5b. Does using the polycyclic organic matter (POM) example (Chapter 3) help explain the
kind of research and development activities and project areas that should be expected as
the ATRS is implemented, or should Chapter 3 be omitted because we now have an air
toxics Multi-Year Plan (MYP)? 9
Vlll
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Charge Question 6
Are the implementation approaches of developing an air toxics Multi-Year Plan, creation of a
cross-laboratory and center air toxics steering committee, and conduct of scientist-to-scientist
meetings on air toxics sufficient to implement the ATRS? 9
Charge Question 7
As the MYP was developed, the intention was for it to reasonably follow from the ATRS. The
foundation of the MYP is the two Long-Term Goals (LTGs). Thus, the segue from the ATRS
to the LTGs should be seamless 11
7a. Do the long-terms goals of the MYP align the ATRS, and do they support the priority
needs of the program and regional offices? 11
7b. Would accomplishing these LTGs enable ORD to meet the Air Pollution Sub-Objective
stated as follows: air toxics research will develop and improve air quality models and
source receptor tools, cost-effective pollution prevention and other control options, and
scientific information and tools to understand and characterize environmental outcomes
associated with nationwide, urban, and residual air toxics risks? 11
Charge Question 8
8a. Are the LTGs appropriate for meeting the Air Pollution Research Sub-Objective? 12
8b. Are the APGs and APMs measurable outcomes and outputs, respectively? 13
8c. Do the APGs develop a critical path to achieve the LTGs? 13
8d. Do the APMs encompass a body of research that "adds up" to logically achieve the
APG? 14
Charge Question 9
Are these resources sufficient to provide air toxics research that will achieve the LTGs and
thereby support the regulatory needs mandated by the CAAA? 14
Other Comments 14
References 16
IX
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Introduction
The EPA Office of Research and Development (ORD) conducts research to better
understand and manage environmental risks. ORD, in consultation with the Office of Air and
Radiation (OAR), developed an Air Toxics Research Strategy (ATRS) and an Air Toxics Multi-
Year Plan (MYP) to help set research priorities. The purpose of the ATRS is to identify air
toxics research needs, to support EPA's Strategic Goal 1: Clean Air. The ATRS is built around
five strategic principles, seven key research questions and many sub-questions. The MYP
presents ORD's plan for addressing those needs in the 2003-2010 timeframe. The MYP is
organized around two long-term goals, annual performance goals (APGs) and annual
performance measures (APMs).
An EPA Science Advisory Board (SAB) Review Panel was convened in response to
ORD's request to review the ATRS and MYP. The SAB's review of these documents was
significantly aided by interactive presentations and discussions with ORD during the Panel's July
23-24, 2003 meeting. This report presents the SAB's review of the ATRS and MYP, responding
to five specific charge questions related to the ATRS, and four charge questions concerning the
MYP.
General Comments
The SAB is pleased that the Agency is attempting to address long-term planning needs
and to better integrate its research planning across ORD laboratories and office. Both the ATRS
and MYP reflect these efforts, extending the planning horizon to 2010. The documents also
convey EPA's consideration of the risk assessment paradigm in its air toxics research planning.
In addition, the SAB commends ORD for presenting the annual performance goals (APGs) and
annual performance measures (APMs) in the MYP in terms of measurable outcomes and outputs
for which the Agency will be accountable. The SAB generally found each document well
organized and of an appropriate level of detail. Neither the ATRS nor the MYP, however,
achieves a sufficient level of planning integration to effectively inform research priorities. The
SAB also found that there is a poor linkage between the ATRS and MYP because they follow
two different and disconnected planning frameworks. In addition, the documents need to be
updated to reflect events, documents, and research findings since the May 2002 ATRS External
Review Draft.
The SAB believes that EPA's approximately $20 million annual funding for air toxics
research is not adequate, given the magnitude of research needs in this area, and the Agency's 20
percent administrative costs are excessive. The Air Toxics MYP cannot be accomplished,
therefore, without significant contributions from other EPA research programs. In addition,
some air toxics research is funded outside of the air toxics research program. For example, while
mercury and bioaccumulative toxins are hazardous air pollutants (HAPs), research for these are
funded under EPA's Strategic Goal 4 (Health Communities and Ecosystems) because they are
multimedia pollutants. As planning and management for these other research programs are
largely independent of the air toxics research program, changes in their priorities and funding
can have important but not immediately visible consequences for implementing the Air Toxics
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MYP. The SAB recommends that EPA broaden its air toxics research planning and management
to more fully integrate research that contribute to, but which are not organizationally controlled
by, the air toxics research program. In addition, the SAB recommends that EPA develop a
transparent accountability process for adjusting the allocation of air toxics research funding
based on measurable research results.
The SAB underscores the need for EPA to articulate how it will integrate within EPA,
and coordinate and collaborate with other research organization, to implement the Air Toxics
MYP. The SAB recommends that the Air Toxics MYP clearly discuss and graphically illustrate
the relationship with other research program multi-year plans, showing all research and funding
that support ATRS implementation. Such a figure was shown by EPA staff at the review
meeting, but was not included in either the draft ATRS or the MYP.
Finally, clearly defining and consistently using the terms "air toxics" and hazardous air
pollutants (HAPs) can improve both the ATRS and MYP. At some places in the ATRS, "Air
toxics" is used broadly whereas "HAPs" refers specifically to the Clean Air Act Amendments
Section 112 list of 188 compounds. In other place in the ATRS and in the MYP, and during
discussion with EPA, the terms are used interchangeably.
Response to the Charge Questions
The following comments summarize the SAB's response to the specific charge questions.
A few additional comments on issues outside the specific charge questions are presented at the
end. All comments must be considered together with the specific reports they address to be
understood in their proper context.
Charge Question 1
la. Does the research strategy provide a sufficient regulatory and research context?
Yes, the EPA's need for a strategic approach to air toxics research and the context for its
application are well described.
Ib. Is it on target in identifying and addressing the expected research needs of the air
toxics regulatory program?
Not entirely. The research strategy identifies and addresses in general terms many of the
research needs of the program in a comprehensive manner. The research strategy, however, does
not set research priorities on those HAPS that pose the greatest risk to exposed populations. The
SAB believes that there has been inadequate recognition that past and current EPA approaches
for designating exposure-response relationships and population distributions of exposure
implicitly incorporate a high level of uncertainty, making their suitability for the determination
of credible residual risk levels for populations or for risk rankings uncertain. The ATRS should
more explicitly focus on the development of methods to characterize uncertainty and variability
in exposure-response relationships and distributions of exposed populations. These methods are
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needed to better characterize potential risks to determine which HAPs warrant additional
research.
The SAB recognizes that risks may be underestimated for certain chemicals or mixtures
of chemicals where uncertainties are very large, for example, due to limited understanding of
biological mechanisms, influence of co-exposure to other agents, and unknown but extreme
variations of sensitivity between species and/or within segments of the human population. The
SAB believes, however, that such underestimates of risk are rare. In consideration of the need
for cost-effective means of reducing population risks from exposures to air toxics and for the
setting of priorities for risk reduction activities, the program will best be served in the long-term
by the application of improved methods for characterizing exposure-response relationships that
explicitly account for uncertainty and variability, rather than overly investing in predictive
toxicology.
Ic. Is the primary purpose of the A TRS (of improving the science underlying the NA TA
Program) appropriate?
Yes. The purpose is highly appropriate. While the detailed refinements addressed in the
ATRS are worthwhile objectives, they may not adequately address a critical long-term need: the
development of methods to determine more accurate exposure-response relationships and that
better characterize uncertainty and variability, as discussed in the SAB's response to charge
question Ib.
Charge Question 2
Do the summary key questions and research needs comprehensively address the
important research that should be undertaken, given the scope of the ATRS?
The application of the risk assessment paradigm to codify research needs for air toxics
results in a relatively comprehensive list of important research activities that far exceed available
Agency resources. The ATRS also provides five principles to guide Agency research decisions.
The SAB does not believe, however, that these principles assist the Agency in priority-setting.
Research priorities should be based on the magnitude of the risk and the need for greater
certainty in risk assessment, such as captured in EPA's Principles 2 and 3 (ATRS, p. 27), and
institutional factors such as in-house resources, research capacity, and knowledge of non-Agency
organizations that may be better able to conduct the needed research. The SAB recommends
developing questions or additions to the strategic principles to facilitate setting Agency research
priorities. Examples of some questions to aid prioritization are:
> Is the research critical to reducing uncertainties before making a regulatory decision?
Considerations should be given to:
a. The results of epidemiological studies indicating elevated health risk and
therefore warranting sufficient research to understand exposure-response
relationships.
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b. Other indicators of elevated risk, such as extent of exposure and potential cancer
and non-cancer toxicity. When EPA RfDs and RfCs are not available, the
Agency should consider using values from other organizations, e.g., California
Proposition 65, Toxic Air Contaminants, and hazardous waste programs. EPA
should also utilize new and/or updated RfDs/RfCs provided in draft assessments
as a basis for identifying research priorities.
c. Extent of exposure to susceptible populations such as children, fetuses, or the
elderly.
d. Extent to which populations exposed are disproportionately subjected to air toxics
and other environmental risks due to economic disadvantage and other factors
related to environmental justice.
e. Extent to which the risk is likely to increase or decrease in the future (for
example, due to changes in the use of chemicals, changes in processes, or changes
in emissions profiles).
> Is the public aware of the risk, or is there public concern? If the public were to be made
aware, would there be concern?
> What is the potential for the research to have a significant impact on understanding the
risk and affecting regulatory decision-making?
> Is the research anticipating a problem, and if conducted would it facilitate risk prevention
and cost-effective environmental management? (See Science Advisory Board 2003:15,
19)
> Does the research address an orphan risk (e.g., from indoor air pollutants for which EPA
lacks regulatory authority) from an important identified source of environmental
exposure? (See Science Advisory Board 2003:4, 18-19)
> Does the research provide the greatest public health benefit for money spent? Is this
research among the top priorities?
Examples of questions to address institutional factors in considering research priorities
are:
> To what extent will the research support major upcoming rules and decisions?
> Is it essential for EPA to develop or maintain a core research capability, e.g., to anticipate
the development of new science areas, and/or to continue core research as part of EPA's
leadership role for specific Federal agency science activities?
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> Does the research duplicate credible research being performed elsewhere? Are other
Federal agencies doing significant research in this area? Could EPA provide sufficient
input to ensure critical research performed elsewhere will meet Agency needs?
> To what extent can the research effort be used to leverage research being conducted
elsewhere?
The ATRS does not adequately address the need for developing improved analytical
methods for ambient monitoring of air toxics. While the need for additional research on
improved analytical methods is acknowledged (Section 5 - Additional Research Desired), the
SAB notes that currently available methods for air toxics are limited. For a number of the 188
HAPs, methods simply are not available. For other HAPs, current analytical sensitivity is poor.
The problems with analytical methods severely limit understanding of ambient concentrations
and spatial variability of air toxics. Improved analytical methods are necessary as EPA, States,
and Tribes develop analytical monitoring networks and are necessary for validation of modeling
used to predict ambient concentrations. Improved analytical methods would ultimately reduce
uncertainty in risk assessment.
Given the limited funds available for air toxics research, EPA is encouraged to consider
alternative avenues for addressing this research need, such as the Small Business Innovative
Research (SBIR/STTR) and Science to Achieve Results (STAR) programs. External research
funding to develop analytical tools and methods through the SBIR/STTR program may be an
effective way to develop analytical tools, or at least significantly extend the capabilities of
techniques under development at EPA. Additional leveraging of EPA air toxics research could
be provided through the application of STAR program funds to support projects listed in Section
5 of the Air Toxics MYP, including fundamental studies on topics such as species' fate and
transformation and risk assessment methodology. These avenues would have the benefit of
leveraging the scarce ORD resources allocated to the study of air toxics.
The Agency utilized the National Research Council's 1983 (NRC 1983) risk assessment
and risk management paradigm in developing its key scientific questions and strategic principles
in the ATRS and long-term goals in the MYP. The SAB believes that EPA should employ an
updated paradigm that emphasizes an integrated approach to the framing of the environmental
problem, the technical risk assessment and risk characterization, the consideration of
environmental decision options, and stakeholder involvement. Application of this paradigm
would uncover research needs, address risks from airborne toxicants falling outside those of
current regulatory focus, and would include research needs to support general risk management
strategies. This would include research needed to:
> Maintain the HAPs list proactively, i.e., add to and remove chemicals from the list.
> Track non-regulated chemicals and sources of airborne pollutants for possible regulatory
action.
> Understand the impact of risks from unregulated sources, such as off-road sources, ports,
and certain consumer products.
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> Assess the risks of mixtures.
> Assess behaviors critical to the management of airborne risks, particularly those from
mobile sources and indoor air.
> Conduct research to support MACT.
Charge Question 3
Are all relevant discipline areas, e.g., emissions, exposure assessment, health effects,
risk characterization, and risk management, addressed at an appropriate and
consistent level of detail, thereby presenting a unified perspective?
The question was poorly formulated in that the conceptual framework for risk assessment
used in the ATRS and MYP is that described in the National Research Council's 1983 "Red
Book" (NRC 1983). As noted in our response to charge question 2, reference to the risk
assessment/risk management (RA/RM) paradigm should be updated to include stakeholder input,
including community concerns. Both stakeholder participation and risk communication are
necessary parts of a comprehensive strategy. Neither Section 1.4 (Risk Assessment-Risk
Management Framework for Air Toxics) nor Figure 4 (The RA-RM Framework) of the ATRS
discusses or acknowledges the significance of stakeholder involvement. Research on how to
accomplish stakeholder engagement, particularly in the risk management phase, appears
warranted.
Similarly, the ATRS does not specifically address risk communication. SAB members
felt this was a shortcoming of the research strategy. There is significant potential for
misunderstanding and misinterpretation of the results of the risk assessment/management
process. The SAB recommends that ORD address these issues in any revised ATRS or, at a
minimum, consider these in their approach to reducing uncertainties in air toxics risk
assessments (Multi-Year Plan Long-term Goal #1) and in implementing risk reduction of air
toxics (Multi-Year Plan Long-term Goal #2).
Finally, the Presidential/Congressional Commission on Risk Assessment and Risk
Management (Presidential Commission 1997) observed "it is time to modify the traditional
approaches to assessing and reducing risks that have relied on a chemical-by-chemical, medium-
by-medium, risk-by-risk strategy." The ATRS emphasizes the study of air pollutants one
chemical at a time and delays the consideration of mixtures. There are advantages to beginning
the study of mixtures now rather than later: regulated sources always emit mixtures, people
always breathe mixtures.
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Charge Question 4
4a. Are the strategic principles listed in Chapter 2 appropriate?
Yes. Collectively, the five Strategic Principles provide a guiding philosophy for the
development and enactment of the ATRS. While the strategic principles are appropriate,
discussion on what the principles actually represent relative to the ATRS is sometimes unclear or
lacking. For example, Strategic Principle 2 establishes that the research and development
activities will be focused on those air toxics for which risks are greatest to people and the
environment. Table 5 gives the thirty-three pollutants on its Urban HAPs list, Table 6 gives
twenty-one pollutants on its Mobile Source Air Toxics list, Table 7 gives eighteen pollutants on
its Indoor Air Toxics list, and Table 8 gives fifty-four pollutants for stationary sources subject to
early residual risk standards. In Table 9, there is a crosswalk of selected pollutants in terms of
the four chemical structure HAP groups proposed in the ATRS. As discussed at several points in
this SAB report, there should be a prioritization of the pollutants based on greatest risks to
develop the most effective research strategy and multi-year research plan.
While one can hardly argue against the strategy reflected in Principle 2, the ATRS
document does not provide much discussion about which factors to consider in establishing
priorities. Uncertainty factors are emphasized as important for ranking compounds; however,
projected human exposure levels, the number of exposed individuals, and the potential severity
of response needs to be linked if any priority-setting process is going to address the concept
espoused in Principle 2. As stated, Principle 2 should probably be the first strategic principle.
For the current Principle 1, the concept of grouping is reasonable, but it would be better to
refrain from referring to grouping by specific chemical class since there are a number of
alternative grouping strategies that could be reasonably employed (see SAB's response to Charge
Question 5).
4b. Do they facilitate effective decision-making for prioritizing future air toxics research?
The strategic principles have the potential to facilitate effective decision-making for
prioritizing components of the research strategy. Currently, however, specific criteria and
relative weights to be applied to each individual criterion are lacking. An effective strategy for
such a large-scale program would benefit from a tiered approach. One should not assume that
because little is known about a compound there is little risk for adverse health and ecological
outcomes. Some minimal criteria for physico-chemical, potential population exposure (e.g.,
production volume, volume of formation, etc.), and biological data should be established as the
first tier of information for prioritizing compounds for study. Criteria beyond the minimal set
could provide a second tier for deciding whether additional information needs to be developed.
Without a carefully prioritized and integrated research approach, EPA may spend large amounts
of money and have little to show for it.
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Charge Question 5
So. Is the draft ATRS approach of grouping air toxics (Strategic Principle #1), first by
chemical characteristics and then by regulatory need, appropriate, and what other
approaches might be explored to efficiently group air toxics?
The grouping of air toxics by chemical characteristics and then by regulatory need
appears to be a step backwards from what is already known about the risks associated with these
substances. A narrow list of compounds has been identified on which EPA intends to focus. For
example, EPA has designated an urban "Dirty 30" (actually 33 out of the 188) air toxics list
based on, first, their presence in the human environment and, second, the toxicity of each
chemical. In addition, the ATRS will not address all the pathways that introduce air toxics to
humans and increase the predicted risk. The proposed grouping in the ATRS/MYP is less
helpful than a grouping based on, for example, mode of action or relative toxicity of each
substance, where data are available. In general, if a substance has both carcinogenic and
noncarcinogenic modes-of-action, one can expect to reach the carcinogenic level of concern
(e.g., a risk of 1 in 106) at a lower concentration than the noncarcinogenic level of concern (e.g.,
LOAEL or RfC).
The ATRS and the MYP should emphasize that grouping schemes, whether by
physicochemical properties, toxicity, or mode-of-action, are ways of improving the efficiency of
research planning to address specific questions and should not be confused with priority-setting.
Setting priorities requires a separate process and, in general, the simultaneous consideration of
more factors than does grouping. Different research questions may benefit from different ways
of classification. For example, studies of environmental fate and transport may benefit from
grouping by physico-chemical properties, while consideration and testing of emission control
technologies might benefit from grouping by source. One must be cautious when grouping
based on mode-of-action or toxicity because specific chemicals may have multiple modes-of-
action or types of toxicity.
Many HAPs/air toxics, particularly those with multi-pathway routes, are being addressed
in other research program MYPs. Consequently, the SAB had difficulty in determining whether
certain classes of HAPs are receiving adequate coverage under the ATRS/MYP classification
scheme. Metals are one such example. Metals are addressed in the Particulate Matter (PM)
MYP, but the goals of the PM MYP are likely different (i.e., understanding transition metals and
oxidative stress) from the air toxics MYP. In addition, the broad classification of metals together
does not further their reclassification and prioritization on, for example, a biological basis. The
mode-of-action and biological targets vary widely among the metals. It is therefore difficult for
the SAB to answer the question as to whether the air toxics program is "comprehensive" without
knowing what air toxics issues are also touched upon in the PM and other research program
MYPs.
The most significant shortcoming of the current classification scheme is the inability to
identify and address air toxics not included in Table 9, the "Crosswalk of Chemical Structure
Groups and Priority Program Air Toxics." For example, "ground-truthing" exercises at the state
or local/community level, which may identify new pollutants of concern, would not be addressed
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by the current ATRS/MYP approach regardless of their risk level. At best, the scheme is at a
level superficial enough (organics vs. inorganics) to incorporate newly found substances in the
proper sub-classification, but it does not contribute to an understanding of their significance for
potential community health risk (the responsibility of EPA).
The SAB recommends that the development of a priority research list of air toxics be
iterative and open to modification, with clearly stated criteria for modification, addition to, or
deletion from the list. The process must be able to accommodate a completely different
approach as the state of the science evolves. An example is provided by the evolution of the
National Priority List of the Superfund program: Superfund's Hazard Ranking System
underwent significant changes as both science and evaluative methodologies improved. Such
mechanisms for changes and improvements can be incorporated as appropriate, as determined
either by ORD or in consultation with stakeholders.
5b. Does using the poly cyclic organic matter (POM) example (Chapter 3) help explain the
kind of research and development activities and project areas that should be expected
as theATRS is implemented, or should Chapter 3 be omitted because we now have an
air toxics Multi-Year Plan (MYP) ?
The POM example is reasonable to include in the ATRS. Since the ATRS predates the
MYP by at least a year, there are significant mismatches between its structure, completeness, and
the level of detail in the MYP. At a minimum, there should be an updating of that part of the
ATRS to include cross-links to the MYP. The SAB recommends that the POM example be
carried over from the ATRS to the MYP and re-cast to be closely tied to the elements of the
MYP. The POM example is appropriate for both Air Toxics documents because of its suitability
for illustrating a group of compounds (making allowance for additional specific substances that
may emerge as substances of concern are added in more detail) whose primary pathway and
exposure route of concern is air and inhalation. Thus, the class of POM substances is clearly part
of the air toxics documentation; separate from other substances such as mercury and dioxins with
more complex routes of exposure (and the subject of other, separate research program MYPs). A
narrative about which major lines of research will be pursued by the Agency in examining POM
would be a significant addition to the POM example and could help provide better linkage of the
MYP to the ATRS. The SAB does not endorse the POM as necessarily the best example to use
in the ATRS and the MYP (i.e., versus an example based on one of the other grouping
categories). The SAB endorses, rather, the use of an example substance or class of substances to
illustrate how the strategy and plan relate for one category of compounds.
Charge Question 6
Are the implementation approaches of developing an air toxics Multi-Year Plan,
creation of a cross-laboratory and center air toxics steering committee, and conduct of
scientist-to-scientist meetings on air toxics sufficient to implement theATRS?
The implementation of the ATRS is to be accomplished by three methods: the Multi-Year
Plan (MYP); cross-laboratory implementation committees; and scientist-to-scientist meetings.
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All of these venues are reasonable approaches to developing and implementing the ATRS. The
SAB offers the following comments to enhance these approaches.
If the MYP is meant to implement the ATRS, there must be obvious links between the
two. This is not presently the case. The ATRS covers far more work than can be undertaken by
the EPA, given budgetary limitations. Therefore, the MYP must clearly indicate what piece of
the effort described in the ATRS the EPA will undertake. Where possible, the Air Toxics MYP
should indicate the work expected to be undertaken by external research units such as academic
laboratories and centers, private laboratories, and other government agencies. Mechanisms for
EPA interaction with those external bodies should also be described.
Priorities need to be clearly stated in the ATRS and clearly addressed in the MYP. Such
clarity is presently missing. The long-term goals of the MYP are so broad as to be almost
meaningless. More focused goals related to the priorities developed in the ATRS would be much
more useful.
The cross-laboratory implementation committees are essential to integrate the air toxics
programs across all of the EPA programs and offices. The effectiveness of these committees will
depend on the importance and support provided by upper level management.
The scientist-to-scientist meetings are also essential for efficient exchanges of
information between science participants in the air toxics program. EPA management should
offer opportunities for such exchanges on a regular basis. These exchanges can range from
informal discussions in the local laboratory, to programmatic seminars, to national meetings
across all program offices. For all of these exchanges it will be essential to include external
scientists. EPA scientists have informal discussions with external scientists at major scientific
meetings. For programmatic seminars, external scientists need to be invited as guest speakers.
External guest speakers should always be a major part of national, across-program meetings.
Part of the implementation plan described in the ATRS states that individual compounds
would be studied first, then by study of susceptible individuals, and followed by studies of
mixtures. Thus, the recommended paradigm follows the traditional approach of looking at one
toxicant at a time, despite the fact that sources always emit mixtures and people always inhale
mixtures of pollutants. There are advantages to moving beyond the study of single components
to the more relevant study of mixtures. One advantage is that regulatory measures can be
applied to the mixtures emitted by some sources. Another is that health effects studies on
source-related mixtures will provide more realistic data for use in risk assessment for public
health than can be obtained by the study of single compounds. Hazard identification and dose-
response assessments can be done in toxicity studies in animals exposed to the actual emitted
mixtures, such as diesel exhaust, wood smoke, or coal combustion emissions. Emphasis should
be placed on characterizing risks at low, environmentally relevant exposure levels. Such studies
can provide more relevant health effects information than what can be obtained by studying
single compounds or even binary mixtures.
There clearly are not sufficient funds to address adequately all of the individual Annual
Performance Measures (APMs) that are part of the Multi-Year Plan. This makes it imperative
that the Agency be willing to reprogram funds among laboratories as the need arises. For
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example, if a proposed research avenue does not pan out, the resources should be shifted to
another APM that may or may not reside within the same laboratory. As another example, the
current budget allocation does not provide adequate resources for the proposed three to five
community level exposure and epidemiology studies, and the RCT may well need to shift funds
among laboratories to ensure that this high priority APM is accomplished.
Charge Question 7
As the MYPwas developed, the intention was for it to reasonably follow from the
ATRS. The foundation of the MYP is the two Long-Term Goals (LTGs). Thus, the
segue from the A TRS to the LTGs should be seamless.
7a. Do the long-terms goals of the MYP align the ATRS, and do they support the
priority needs of the program and regional offices?
7b. Would accomplishing these LTGs enable ORD to meet the Air Pollution Sub-
Objective stated as follows: air toxics research will develop and improve air
quality models and source receptor tools, cost-effective pollution prevention and
other control options, and scientific information and tools to understand and
characterize environmental outcomes associated with nationwide, urban, and
residual air toxics risks?
This charge question was too broadly stated, as were the two LTGs developed in this
MYP. Although the LTGs are aligned with the ATRS, it is difficult for this SAB to address this
question without addressing the annual performance goals (APGs) and annual performance
measures (APMs), which are addressed in the SAB's response to Charge Question 8.
Consideration should be given to deleting such a broad charge question in future reviews.
There is not a seamless transition from the ATRS to the MYP. The ATRS is built around
its five principles and its seven key research questions with their many sub-questions. The MYP
is organized around its APGs and related APMs. Clearly, the research program envisioned in the
ATRS is more encompassing than the MYP due to budget and other resource limitations. To
make the segue from the ATRS to the MYP more transparent, it would be helpful in future Air
Toxics MYPs to refer to the key ATRS question(s) being addressed in each APG and APM as is
currently done in Chapter 3 of the ATRS.
Succinctly stated, LTG 1 is to reduce uncertainty in air toxics risk assessments and to
conduct three to five community-level exposure and epidemiological studies to characterize the
risk of air toxics. The first part is the overarching goal of much of the air toxics program.
Conducting the three to five community-level exposure and epidemiological studies is a worthy
goal, but it is less well developed in the MYP. There are no APGs or APMs that specifically
schedule these studies that are to occur at the end of the MYP. Although the SAB considers
these studies critical to the overall air toxics program, it concludes that under current funding
levels there are not sufficient resources in the air toxics program to conduct these studies.
Leveraging resources with funds from the Particulate Matter program or other resources within
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the Agency will be essential to successfully conducting community-level exposure and
epidemiological studies.
LTG2 calls for the production, by 2008, of 15 new or modified tools in the form of
methods, models, or assessments that enable national, regional, or local officials to identify
"cost-effective" approaches to reduce risks from air toxic sources. As stated, this goal is so
vague that it will undoubtedly be achieved.
The SAB cannot adequately address whether the long-term goals of the MYP meet
program and regional needs. They do support regulatory programs such as residual risk and seek
to develop improved tools for evaluating air toxics. ORD representatives indicated that they
were responsive to the needs of the clients, which are in this case the Office of Air and Radiation
and EPA's regional offices. They indicated that they had consulted with an EPA regional
representative in developing the MYP and were to meet on September 9-12, 2003, with EPA
regional representatives on their air toxic needs.
Since the MYP has specific APMs for modifying the Community Multiscale Air Quality
Model to allow modeling of some air toxics, it addresses the development of air quality
modeling. On the other hand, the MYP does not have specific APMs that address the
development of source-receptor models. Furthermore, the MYP does not have APMs that
address effective pollution prevention and other control options beyond the development of
tools. Reference to or coordination with the Pollution Prevention MYP could bolster the latter
needs.
Charge Question 8
80. Are the LTGs appropriate for meeting the Air Pollution Research Sub-Objective?
Referring back to the Air Toxics MYP Objective 1.5 on Science/Research, the goal of
which is to provide methods, models, data, and assessment research through 2010, LTG1 would
theoretically benefit from the promised advances in research. It must be noted, however, that the
extent of the uncertainty reduction is unstated and we can only speculate about the credibility of
the three to five studies to be performed with resources that are likely inadequate. As stated
elsewhere in this review, if the EPA does not try to develop means for addressing uncertainty
and variability in risk estimates (rather than conventional estimates), if the Agency does not
provide sufficient resources to accomplish the studies in more than a superficial fashion, then
LTG1, while achievable in the very general terms stated, could well be a waste of time and
resources.
Regarding LTG2, the goal is also exceedingly broad, as we state in response to Charge
Question 7. It is axiomatic that, at least for non-threshold pollutants, any reduction in source
strength will lead to reductions in exposure and the health risks associated with exposure. For de
minimis risks, however, it is not possible to identify cost-effective tools for the very small
degrees of hypothetical risk reduction that might be achieved. For lifetime risks to the individual
in the 10"4 to 10"6 range, the health benefits of source strength reduction would depend on the
nature and severity of the health effect and the size of the exposed population. Furthermore, the
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evaluation of the cost-effectiveness of source strength reduction would depend on, in addition to
the inferred population risks, the credibility of the risk assessment. For most air toxics, risk
estimates can be expected to remain highly uncertain in 2010 unless the program is reoriented
soon to focus more explicitly on means to develop best estimates of exposure-response and
population exposure distributions.
8b. Are the APGs andAPMs measurable outcomes and outputs, respectively?
Table 6.0, describing APGs and APMs, is the most encouraging part of the MYP in that it
briefly describes the specific tasks planned through 2010 and covers research that can fill many
of the information gaps that have long limited EPA's ability to produce credible risk
assessments. A reviewer comes away from an examination of this table with a high level of
confidence that the exposure parameters and health effects of acute exposures to air toxics will
be much better defined if this research is carried out. The tasks addressing the effects of chronic
exposures represent generally appropriate and useful steps toward better risk assessment tools for
chronic disease endpoints. They are reasonable choices in view of the limited research resources
that are likely to be available in the 2003-2010 timeframe. Even with successful completion of
these tasks, however, there will still be many information gaps left unfilled. Despite this caveat,
EPA is to be commended for presenting the APMs in terms of measurable outcomes and outputs
for which the Agency will be accountable. In any revision of the MYP, the SAB suggests that
EPA:
1) Include year of initiation in listing of APMs and APGs and year of completion;
2) Provide alternative means of organizing APGs/APMs that are grouped by lines of
inquiry (such a chart, if organized as a timeline, might take care of our first
suggestion); and
3) Include in the Air Toxics MYP a section that reviews prior MYPs and summarizes
successes, goals/objectives not accomplished, and changes made to the plan, and
discusses reasons for changes.
8c. Do the APGs develop a critical path to achieve the LTGs?
The APGs are a logical and defensible subset of research goals that fit well into a
strategic approach to the overall objectives of the Air Toxics program. They could be better
organized, however, such as according to logical subsets of goals and their links to elements of
the strategy. The APGs did not include one critically important area of research needed to make
them a comprehensive program: information about the spatial variation of outdoor
concentrations. This is of paramount importance in our efforts to assess human exposures to air
toxics of ambient origin. In addition, outdoor concentration data are necessary for both the
development and evaluation of source-to-receptor air quality models (e.g., ASPEN).
Considering the large spectrum of air toxics that need to be measured, development and
operation of a comprehensive outdoor air-monitoring network will be prohibitively expensive.
To overcome this problem, one can focus on chronic exposure assessments. Since we are
especially concerned about cancer and other chronic disease outcomes, it will be highly
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advantageous to develop sampling techniques for collecting long-term samples, e.g., seasonal
and/or yearly specimens. This can be achieved using diffusion samplers or low flow samplers
that operate intermittently, e.g., a few minutes per hour. Use of inexpensive sampling techniques
for collecting long-term samples and their inherent advantages in terms of reduced number of
samples for analysis by sensitive laboratory methods can make it possible to develop a
comprehensive spatial network in a cost-effective way.
8cL Do the APMs encompass a body of research that "adds up" to logically achieve the
APG?
Largely, they appear to, and ORD is commended for organizing this complex effort in an
integrated manner. The specific tasks in the APMs need to be more clearly stated and should not
be limited, however, as they were in this draft by a count of letter characters.
Charge Question 9
Are these resources sufficient to provide air toxics research that will achieve the LTGs
and thereby support the regulatory needs mandated by the CAAA?
A clear indication as to how resource allocation decisions will be made among the
research needs articulated in the ATRS and MYP is lacking. The SAB feels strongly that it is
unlikely all topics identified in the ATRS can be addressed with the limited resources available
to EPA. As previously discussed, there is a need for a clear strategy for setting research
priorities. In the SAB's view, available resources are perhaps sufficient to achieve parts of the
APGs and APMs that are listed in the MYP, but probably not to fulfill the regulatory needs as
reflected in the long-term goals. There simply is not enough detail in the Air Toxics MYP to
judge the scope of the proposed program relative to context or to available funding. The Air
Toxics program is sorely under funded if the Agency is serious about achieving the long-term
goals of the program. Of the 19.9 million dollars allocated as of mid-2003 for the ATRS, almost
20 percent is devoted to administration. This amount is not warranted, reflecting the bureaucracy
of the Agency and implying that the actual allocation of FTEs for air toxics differs significantly
from the FTE resources per the FY03 President's proposed budget.
To make inroads on the risk assessment needs, it would probably be better to address the
unmet needs through the STAR program with a research grant Request for Application (RFA).
The RFA should encourage grant submissions from risk assessors less bound by the conventional
EPA risk assessment paradigm and who are willing to develop new methods to construct best
estimates and address uncertainty and variability in risk.
Other Comments
SAB Panel members noted various issues that did not necessarily relate to a specific
charge question but on which they wanted to convey their insight and feedback. These points are
listed in the following bullets and are not in any order of relative priority or importance.
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• The background should include some description of the origin of and recommendations
made at the EPA SAB Workshop on the Benefits of Reductions in Exposure to
Hazardous Air Pollutants: Developing Best Estimates of Dose-Response Functions,
chaired by Dr. Michael Kleinman (Science Advisory Board 2002).
• Reducing uncertainty (LTG1) is a very important goal in terms of the credibility of
EPA's science products generally; not only for the Air Toxics program determinations of
residual risk. It is also critical to the Agency's needs for comparative risk assessments,
cost-benefit analyses, and risk communication. For each of these important activities,
there is a need for means of producing exposure-response relationships that take into
account variability and uncertainty in preference to approaches currently used.
• The Research Coordination Team needs to be willing to reprogram across laboratory
lines and not adopt an "everyone gets and keeps their piece of the pie" approach if the
program is to remain integrated and responsive.
• Adding a section at the beginning of the Air Toxics MYP that provides an overview of
various activities going on in other research program MYPs would be very helpful to
readers and reviewers of the MYP. Such a section would help place into context the
activities in the Air Toxics MYP.
• The SAB was pleased to see that exposure assessment is well addressed from both an
ambient and indoor perspective. This reflects EPA's effort to be comprehensive in
examining exposures.
• If other research programs MYPs are written at a similar level of detail as the Air Toxics
MYP, a major aspect of an effective review of any Multi-Year Plan is the ability to have
significant interaction with EPA staff during the review. Placing an emphasis on
developing refined and focused charge questions will help a review panel in providing
constructive feedback to the Agency.
• There should be periodic involvement by an SAB committee to review the strategy and
annual plan components and to provide advice and feedback to the Agency.
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References
NRC. 1983. "Risk Assessment in the Federal Government: Managing the Process." Washington,
DC: National Academy Press.
Presidential Commission. 1997. "Risk Assessment and Risk Management in Regulatory
Decision Making. Final Report of the Commission. Volume 2." Presidential/Congressional
Commission on Risk Assessment and Risk Management.
Science Advisory Board. 2002. "Workshop on the Benefits of Reductions in Exposure to
Hazardous Air Pollutants: Developing Best Estimates of Dose-Response Functions: An SAB
Workshop Report of an EPA/SAB Workshop, EPA-SAB-EC-WKSHP-02-001." Pp. 18.
Washington, DC: U.S. Environmental Protection Agency.
—. 2003. "Review of the FY2004 Science and Technology Budget Request for the U.S.
Environmental Protection Agency: A Review by the U.S. EPA Science Advisory Board Science
and Technology Review Panel, SAB-EC-03-006." Pp. 47. Washington, DC: U.S. Environmental
Protection Agency.
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