4>EPA
Unit«d StatM $ei«nta Advfeery EPA-SAS-EPEC-92-023
Environmental Bo»rd (A-101J August
Protection Aa*ncy
SAB REPORT: REVIEW
OF THE PROCESS AND
RATIONALE FOR
DEVELOPING ECOLOGICAL
RISK ASSESSMENT
GUIDELINES
PREPARED BY THE ECORISK
SUBCOMMITTEE OF THE
ECOLOGICAL PROCESSES AND
EFFECTS COMMITTEE
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\
I UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
f WASHINGTON D.C,
August U, 199/.
OFJ1CE OF
THE ADMINISTRATOR
SCIENCE ADVISORY BO4JUB
EPA-SAB-EPEC-92-023
Mr. William K. Reilly
Administrator
U.S. Environmental Protection Agency
401MSt,,SW
Washington, D.C. 20460
RE; SAB Review of the Process and Rationale for Developing Ecological Risk Assessment
Guidelines
Dear Mr. Reilly,
The Ecorisk Subcommittee of the Ecological Processes and Effects Committee
(EPEC) of the Science Advisory Board (SAB) has completed its review of the Risk
Assessment Forum's (RAF) proposed ecorisk assessment process and plan for developing
ecorisk assessment guidelines. The Subcommittee met on March 26-27,1992 to conduct this
review.
The RAF requested that the SAB review their preEaiinmry plans for developing
guidelines which include the generation of issue papers and case studies. In particular, the
RAF requested comments on the suitability of using their proposed process for structuring
ecological risk assessment guidelines and on the adequacy of the list of issue papers and case
studies. In the past the SAB consulted with the Forum on concepts that should be covered in
the Agency's approach to ecological risk assessment, and EPEC has received periodic
briefings on ecorisk guideline activities. Further, EPEC has identified Ecorisk Assessment
and Guidelines Development as major topics for long-term consideration.
The Subcommittee commends the Agency for its development of a "Framework for
Ecological Risk Assessment" (Framework) as a basis for ecorisk guidelines. The concepts
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described in the Framework are well-conceived and broad enough in scope to include current
Agency ecorisk activities. However, as defined by the RAF, guideline development depends
on input from the issue papers and case studies that will be developed in the future, Ecorisk:
assessment is in its infancy in terms of development and, as such, the guidelines program and
ail of its components need to remain flexible and capable of incorporating new findings. In
order to clarify that process, it would be most helpful if the Framework included some
explanation of what is meant by ecological risk beyond the definition. It would be most
instructive to discuss who or what is at risk and discuss some examples of both a narrow
definition of ecorisk related to particular species or ecosystems and a broader definition such
as the risk of irreversible departure from a healthy sustainable condition. Such an exposition
may fit into the discussion of the conceptual model and in the future, it could be illustrated
by the case studies.
We understand that the intent and desire of the evolving risk assessment effort is to
provide managers and scientists with quantitative tools for making risk-based decisions. The
Framework must define the steps in the assessment process, the roles of the assessors and
managers, and encourage them to help the risk takers understand the consequences and the
alternatives for mitigation associated with those risks. In order to achieve these objectives,
the Agency must provide additional staff time and resources because progress has been slow
to date and the most significant tasks still lie ahead. For the short term, the Agency may
need to rely heavily on the technical input from outside experts. In addition, Agency
managers and the RAF itself must recognize that the Forum has a key role in communication
of risk assessment approaches and coordination with risk managers through the development
of guidelines to assure that ill needs are considered. The Subcommittee believes that RAF
should also have a role in the promotion of research on critical ecorisk issues.
Today, most ecological risk assessments are at best semi-quantitative or qualitative
statements patterned after either the chemical-based approach for human health or a broad
environmental impact assessment which lacks specific endpoints. Risk assessment procedures
as we know them today are data intensive and costly to perform. The RAF must strive to
simplify the procedures and reduce costs.
The Subcommittee recommends that the framework document and the implementation
strategy be revised to make the process more interactive and iterative and to expand its
ecological focus on non-chemical stressors, including biological stressors. The Subcommittee
has also included a number of specific comments and suggestions to clarity the structure and
ultimate use of the guidelines as well as a request to more fully reflect comments of scientists
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outside EPA and other groups. The Subcommittee Is concerned that the process diagram as
presented in the framework document is flawed because it does not clearly show the level of
iterative and interactive processes which may occur between the components of the ecorisk
assessment. Likewise, the Subcommittee recommends that the RAF modify the exposure
assessment component to be called the "stressor-exposure assessment". The SAB
recommends that a similar modification be made for the term in human health risk
assessment paradigm. The implementation strategy needs further emphasis on guidance for
non-chemical stress, mechanisms for meeting ecorisk research needs, and procedures for
building technical links with critical Agency programs such as EMAP (especially for
integration and assessment and indicators), the Great Lakes Initiative, Habitat Protection, and
• Global Climate Change, The Subcommittee recommends that these revisions be made within
one year, so they can be reflected in future activities of the RAF and the Agency regulatory
programs that apply the concepts.
The Subcommittee endorses the step of developing a conceptual model as part of the
planning phase of each risk assessment. The RAF should encourage that such models be
developed by multidisciplinary teams and guidance should be provided for use of conceptual
models in an issue paper. The public ^should also be involved in the formulation of the
model. The analysis of risks through exposure/stress characterization and effects
characterization should provide feedback to the model. Unfortunately, the Agency has
relatively few tools available to characterize the risks associated with non-chemical stressors,
multiple stresses, or cumulative effects of stress. Research to develop these tools is urgently
needed and the Subcommittee believes that RAF should have a role in identifying and
promoting those needs.
The Subcommittee also supports the development of Technical Issue papers, as
described at the meeting. More effort is needed to ensure that the development of technical
issue papers and case studies proceed with a high degree of coordination and communicatioQ.
Results of case studies should strongly influence the outcome of issue papers and thus .
maximize their contribution to the development of risk assessment guidelines. We
recommend that additional specific topics be considered: development of the conceptual
model, natural variability (distinct from ecological significance), data acquisition, predictive
and retrospective analysis, a comparison of ecorisk assessment and environmental impact
analysis, and ecorisk research needs. FinaHy, the number of case studies should be increased
and an additional effort should be made to show how case studies support and relate to
guidelines.
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The Subcommittee recommends that the RAF seek early peer review and input on its
future products in their formative stages so that relevant comments can be incorporated into
the final documents. We are particularly interested in how the RAF will address our
recommendations for changes to the Framework and for the integration of human health risk
assessment under the broad conept of ecological risk assessment. The Subcommittee looks
forward to the continued development of the ecological risk assessment process and hopes to
see constructive iterations in the concept. We look forward to future opportunities to review
the products of the case studies and issue papers.
(?.
Raymond Loehr,
Executive Committee
Science Advisory Board
Sincerely yours,
KeSheth Dickson, Chair
Ecological Processes and
Effects Committee
Richard A. Klmirle, Cfaair
Ecorisk Subcommittee
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DEDICATION
On August 1, 1992, Dr. Allan Hirsch, a member of the SAB's Ecorisk Subcommittee,
died unexpectedly. Throughout a, prolific career that included service in the private and
public sectors, Dr. Hirsch distinguished himself as an uncommon man of vision and
principle, consistently calling attention to our responsibility to meet the ecological challenges
confronting this—and future—generations.
Those of us on the Science Advisory Board benefitted from Ms presence and will be
inspired by his memory, to which we dedicate this report.
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ABSTRACT
The report represents the conclusions and recommendations of the U.S.
Environmental Protection Agency's Science Advisory Board regarding a strategy for
developing ecological risk assessment guidelines. The Bcorisk Subcommittee met on March
26-27, 1992 to conduct this review. The Subcommittee found that the Ecological Risk
Assessment program had developed useful guidance to address important issues and
recommended that the Agency increase its efforts to develop issue papers and expanded case
studies. The Subcommittee agreed that the current framework should be viewed as evolving
and that its focus must go beyond traditional chemical stressors dose-response approach of
and it should be revised to effectively include biological stressors. Further, they
recommended that the Forum serve as a major coordination point for scientists within the
agency and in other Federal Agencies. Coordination is particularly important with EPA
programs for EMAP, Geographic Initiatives using ecological criteria, Habitat Protection, and
Global Climate Change. The Subcommittee also recommended that RAF activities should
also be used to stimulate research on ecological risk assessment methods, assessment
techniques, the selection of endpoints and indicators, and assessments of multiple stressors
and cumulative impacts. The Framewdrk should also be expanded to include biological
stressors, data acquisition and public input to the formulation of the conceptual model.
KEY WORDS: Ecological Risk Assessment, Guidelines, Case Studies
ii
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U.S. ENVIRONMENTAL PROTECTION AGENCY
NOTICE
This report has been written as a pajtt 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 a 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 or other agencies in Federal government. Mention of trade
names or commercial products does not constitute a recommendation for use.
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TABLE OF CONTENTS
1. EXECUTIVE SUMMARY , .' , l
2. INTRODUCTION . , , , , . . . 4
2.1 Charge for the Review 4
2,2 Subcommittee Review Procedures . . 5
3, EVALUATION OF THE ECORISK ASSESSMENT PROCESS 6
3.1 Suitability of the Process for EcoRisk Assessment Guidelines 6
3,1.1 Overview of Ecorisk Process 6
3.1,2 Framework Problem Formulation ..................... 10
-3,1.3 Framework - Analysis 11
3.1.4 Framework - Risk Characterization . 14
3.1.5 Risk Management Interface , 14
3,1,6 Status of the Framework .....,,,,.., 15
3,2 Issue Papers 15
3.2,1 Conceptual Model Development 16
3.2.2 Natural Ecosystem Variability 16
3.2.3 Data Acquisition Issue ........... 16
3.2.4 Ecological Risk Assessment and Environmental Impact Analysis . . 16
3.2.5 Uncertainty ,..,,,.,........., 17
3.2,6 Linking of the Issue Papers with the Case Study. Papers . 18
3.2.7 Highlight Research Needs 18
3.2.8 Predictive and Retrospective Risk Assessment 19
3,3 Case Studies 19
3.3.1 Potential Benefits .".:.. 19
3.2.2 Additional Case Studies . 20
4, SUMMARY OF RECOMMENDATIONS 22
IV
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1. EXECUTIVE SUMMARY
The Ecological Processes and Effects Committee (EPEC) formed a Subcommittee
which conducted a review on March 26-27, 1992 of the EPA Risk Assessment Forum's
program to develop Ecological Risk Assessment Guidelines. The major findings,
conclusions, and recommendations of the Subcommittee are as follows;
A, The Ecological Risk Assessment Guidelines program is viewed as a critically
important Agency wide effort. The existing plan, accomplishments to date, and
action items for the future were judged as appropriate to attain the goal to better
understand, maintain, and protect the ecological resources of the nation. However,
for this to happen it will be necessary for the Agency to continue to (1) strive for a
sound scientific foundation in the Guidelines, (2) continue to sensitize and
communicate to both the public and the decision makers the importance of our
ecological resources, (3) seek the support and cooperation of other groups within EPA
and outside agencies, (4) provide appropriate support in funding and personnel, and
(5) proactively look to the future on what the real ecological threats are and what
needs to be done to address them. The Subcommittee perceives that the ecological
risk assessment guideline program is an excellent start towards developing a much
needed, comprehensive approach for assessing the significance of ecological stressors,
It is currently well focused and positioned to provide significant guidance that could
influence most future regulatory initiatives within the Agency. Unfortunately, the
Subcommittee finds that the program is moving very slowly, and lacks the visibility
and support within the Agency to address critical technical issues. The link between
the Risk Assessment Forum and the research program appears too limited for
successful resolution of the technical issues they must face to manage and coordinate
the development of ecological risk guidelines.
B. The Subcommittee commends the Agency for the effort and resulting program plan
that is emerging in the "Framework for Ecological Risk Assessment" and "Plan for
Developing Ecological Risk Assessment Guidelines". The primary components of the
program (Framework, Technical Issue Papers, Case Histories, and Guidelines) were
judged as appropriate but they need to be carried out in a more interactive and
iterative manner. The Subcommittee also agreed that t dealer more descriptive
model should be presented on content and use of the Guidelines to help focus other
program efforts.
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C. The organizational structure presented in the Framework document of Problem
Formulation, Analysis, and Risk Characterization was judged as a useful alternative to
the ecological components which were originally considered.
D. The Subcommittee believes that the Problem Formulation phase needs an even
stronger central emphasis by developing a conceptual model of planning; problem
scoping; communication across agencies; involvement of the risk assessor, the risk
taker, risk manager, and the Public where appropriate; and identification of stressors,
endpoints, ecological boundaries, predictive and protective parameters, and data
quality needs. Within the overall model there needs to be a strong concept that links
stressors, endpoints, and boundaries to the purpose of the assessment and the
alternatives to mitigate the risk,
E. The Analysis phase is based upon the appropriate model of exposure/stress, impact or
effects delineation, and risk characterization. Deficiencies were noted by the
Subcommittee in this section. There is, it appears, a continuing insistence by the
Agency to use the term "exposure characterization* which implies individual chemical
exposure to many scientists and" managers. The Subcommittee recommends that the
Agency use the concept of "stressor-exposure characterization1* which includes
non-chemical stressors. This term should apply to both human and ecological risk
assessments. Ecological risk assessments of the future will have to deal with this
more difficult area of non-chemical stressors, including biological stressors, if
ecological risk assessment is going to fulfill its expectations for the future.
F. Additional points identified as needing inclusion in the Analysis phase were (1)
include the relevant data acquisition, verification, monitoring steps inside the analysis
box and (2) expand beyond chemical and physical stressors and include biological
stressors.
G. The Framework document section on Risk Characterization provides the needed
flexibility for both qualitative and quantitative risk assessments. The Subcommittee
thought that greater attention could be given to the details of (1) interactions and
effective communications in the problem formulation phase between the risk assessor
and risk manager, (2) how the output of risk characterization will be used by the risk
manager, (3) predictive and retrospective risk assessments, and (4) the role of
scientific judgement in the risk characterization process.
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H. The concept of developing Technical Issues Papers was supported by the
Subcommittee. This step will provide the opportunity to keep the science of
ecological risk assessment guidelines technically evergreen. as the science evolves.
Several additional topics deserving consideration for technical papers were added to
the list: conceptual model development with an expanded scope, data acquisition,
predictive versus retrospective risk assessment; natural ecosystem variability (separate
from ecological significance); and a comparison of ecorisk assessment and
environmental impact analysis. These papers and clarifications of other issues
proposed by RAF, should provide the direction for research funding.
I, The Subcommittee concurred with the RAF and placed a high value on the rote of
Case Studies In the overall guideline development process. In fact, it was felt that
more case studies should be developed. Some of these case studies can be taken from
the published literature, to illustrate the breadth and applicability of the guidelines to
all parts of the Agency. In addition, case studies that are simple examples of
ecological risk assessments, based on limited data sets, should be included. It is most
important that an effort must be made to demonstrate more clearly how the case
studies support and are linked to the Guidelines.
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2, INTRODUCTION
The Science Advisory Board (SAB), was asked to review the process, status, and
usefulness of the EPA's efforts to prepare risk assessment guidelines under the direction of
the Risk Assessment Forum. In the past, the SAB consulted with the Forum on the concepts
that should be covered in this Agency program. In addition to the consultation, the
Ecological Processes and Effects Committee (EPEC) has also received periodic briefings on
the status of the ecorisk guideline activity. The Committee has recogniied the importance of
Ecological Risk Assessment Guidelines not only to the EPA, but to other government
agencies. With the current worldwide increased interest in protecting the integrity of our
ecosystems this EPA effort to develop ecological risk assessment guidelines is critically
important. The SAB is very interested in supporting the development of scientifically
defensible and useful guidelines and has thus formed an Ecorisk Subcommittee under the
direction of the EPEC to conduct reviews on this and any future related reviews,
2.1 Charge for the Review
s
The Risk Assessment Forum (RAF) requested that the SAB review their preliminary
plans for developing guidelines including the development of issue papers and case studies.
The Risk Assessment Forum was particularly interested in SAB comments on two issues:
A, Is the ecological risk assessment process as described in the Framework Report
suitable to structure EPA's first Agency-wide ecological risk assessment
guidelines? Are the three major categories of (1) generic principles and
methods for problem formulation, (2) analysis, and (3) risk characterization an
appropriate way to structure future guidelines? Additional guidance specific
for particular ecosystems, stressors, endpoints and other areas would be
developed as feasible in the first guidelines or in subsequent stages of the
overall guidelines development program.
B. Are the eight issue paper topics listed below and detailed in the plan for
guidelines development useful and sufficient to provide technical guidance for
the ecological risk assessment process and the development of guidelines?
Should any topics be added or deleted?
1. Strc&sor-Ecosystem Interactions
2. Endpoint Selection
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3. Characterization of Exposure
4. Characterization of Ecological Effects
5. Risk Integration Methods
6. Uncertainty Analysis
7, Ecological Recovery
8, Ecological Significance
2,2 Subcommittee Review Procedures
The Subcommittee was provided a report entitled "Framework for Ecological Risk
Assessment" describing the basic terminology and elements of the ecological risk assessment
process, a "Plan for Developing Ecological Risk Assessment Guidelines", and the charge for
the review. The Subcommittee also received copies of the "Peer Review Workshop Report
on A Framework For Ecological Risk Assessment", and the "Report on the Ecological Risk
Assessment Guidelines Strategic Planning Workshop", These latter two documents were the
product of two workshops conducted in the spring of 1991 and were published along with the
Framework Document following the review. EPA initially considered structuring ecological
risk assessment guidance primarily around ecosystems, levels of ecological organization, or
stressors. However, as a result of the Risk Assessment Forum's 1991 peer review
workshops, participants recommended that the first Agency-wide ecological risk assessment
guidelines be structured around the major phases of the ecological risk assessment process as
they are now outlined in the Framework Report: these categories are problem formulation,
analysis, and risk characterization. The Subcommittee met on March 26-27, 1992 in
Washington, D.C to review these materials and discuss the charge. The Subcommittee also
provided comments on the Framework document and the needs for RAF involvement in the
research planning process. At the conclusion of the meeting, the Chair summarized the
preliminary comments of the Subcommittee for the public and the Agency. A draft report
was prepared by the Subcommittee and provided to the Executive Committee for
concurrence. The reviewers from the Executive Committee offered several comments,
including the suggestion that human health risk assessment should be integrated with ecorisk
assessment which the Subcommittee chair has adopted.
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3, EVALUATION OF THE ECORISK ASSESSMENT PROCESS
3.1 Suitability of the Process for EcoRisk Assessment Guidelines
3.1.1 Overview of Ecorisk Process
The Subcommittee commends the Agency for its efforts in the development of a
"Framework for Ecological Risk Assessment* as a basis for development of Agency-wide
ecological risk assessment guidelines. The Framework Report with the three phases of (1)
problem formulation, (2) analysis, and (3) risk characterization provides a useful
conceptualization of the ecorisk assessment process. Each of the phases are broad enough in
scope to include the various types of ecological analysis and assessments currently being
used. Guideline development will, however, also require input from the yet to be developed
Issue Papers as well as the compilation of Case Study reports. The Subcommittee believes
that the ultimate success and usefulness of the Agency's Ecological Risk Assessment
Guideline program will be improved if the Framework document and implementation strategy
considered incorporating the items discussed in this report,
The Subcommittee agrees with the approach of using issue papers and case studies to
assist with the development of guidelines, but the former must be scoped and have criteria
for consistency and the case studies must be linked to the issue papers. WMle the
Subcommittee understands the need for Agency guidelines and commends the effort of
dealing with diverse needs, the guidelines/framework should represent primarily a synthesis
of existing literature. The Subcommittee lists several important issues that need to be
addressed and which will determine how well we can perform ecological risk assessments;
these include data acquisition, comparison of ecorisk assessment and environmental impact
analysis, and issues for ecorisfc assessment research. They also recommended that several
proposed papers be modified; two papers should be combined to discuss the development and
scoping of conceptual models, natural ecosystem variability should be treated separately
from ecological significance and the paper on uncertainty analysis should be expanded. The
Subcommittee also recommends that EPA significantly expand the number and type of case
studies to illustrate the applicability of risk assessment across the Agency,
Ecorisk assessment is in its infancy in terms of development and as such, the program
and all of its components need to remain flexible and capable of incorporating new finding.
The model as presented in the Long Range Plaa has three components; Technical Issue
Papers; Case Histories; and Guideline Development, The Subcommittee does not view these
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as a linear process and recommends that the components be presented as an interactive and
iterative process as shown in Figure L
Framework
Formulation
Analysis
Rtik Characterization
Figure I Relationships of
Ecological RisJc Assessment
Components
At this time the Ecological Risk Assessment Guidelines documents are not well
defined. The Subcommittee agreed that additional effort is needed to better define in the
Framework document many of the potential issues surrounding Guideline development such
as their nature* scope, intent, structure, and use. There is a need to focus on a better
description of the Guidelines so that the path to get to them is dearer.
Success will also be contingent upon numerous other factors. There will be a need to
maintain the scientific input that is currently planned through use of workshops and meetings.
Related to this is the important need to solicit and involve other governmental agencies at the
state and federal levels. Without their cooperation and involvement as partners in the entire
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program, it will not be utilized to its full beneficial potential. Other issues such as adequate
funding and sufficient time for full program development will help assure a valued and useful
product.
3.1,1.1 The relationship between human health risk and ecorisk assessment
The foundation for Ecological Risk Assessment Guidelines probably emerged from the
Human Health Risk Assessment Guidelines program, which may in fact be a simpler
challenge than ecological risk assessment. The Subcommittee finds many similarities
between the programs, but ecorisk assessments may involve a variety of levels of biological
organization and interactions which are not considered in single species model human health
risk assessments. The most basic reason is that for the assessment of human health risks,
data from many species are used to estimate effects in one species - humans. Data from
simpler levels of organization (molecular - cellular * tissue/organ - organism) are used to
assess potential effects in the human individual; and in this case, humans are obviously at the
highest level of organization in the assessment matrix. In the development of criteria for the
protection of ecosystems, we are attempting to use data from lower levels of organization
(molecular - cellular - organism) to predict effects on higher levels of organization (individual
organism -population - community - ecosystem), where humans are only one species within a
complex ecosystem. Fortunately, human health risk assessment provides a well developed
model for the species level assessment which can be incorporated into the ecorisk assessment
process. The large body of knowledge on human health risk assessment has often been
considered as a model for ecorisk assessment. Actually, human risk assessment is a
component of ecorisk assessment, just as man exists within the environment. In some cases,
man's activities and choices pose the most significant risks to other species, populations,
communities, and ecosystems. The Subcommittee recommends that RAF consider developing
this type of approach, to build on past experience, harmonize the various forms of risk
assessment, and find new opportunities to balance and communicate relative risks.
From a historical perspective, BPA*s water quality criteria program and human health
risk assessment guidelines required several revisions in scope and methods over many years
as new technology changed. Therefore, the Subcommittee agrees with RAF that the ecorisk
assessment process is one that is very likely to evolve to new levels of understanding and
thus the guidelines, case studies, and issue papers, The Subcommittee further believes that
the Framework will need to be reviewed and updated periodically.
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3,1.1,2 Simplification of the Process and Graphics
There is a need to simplify and modify the level 2 diagrams in the Framework
document. The level 2 descriptions of the Risk Assessment process shown as Figure 3 and
Figure 4 in the Framework document are contusing (Appendix 1). Many boxes with
redundant contents should be combined, la Figure 3 the boxes identified as Exposure
Profile and Stressor-Response Profile can be eliminated or shown more appropriately as
outputs of the analysis. The associated text discussion can also be eliminated or at least
condensed into the Stressor-Exposure Analysis and Ecological Response Analysis Phases.
Figure 4 is confusing and should be simplified. In the Sisk Description box, the
process of "Ecological Risk Summary" adequately captures what occurs and should include
the "Interpretation of Ecological Significance*. The "Interpretation" box should be
eliminated.
3,1,1,3 Coordination within the Agency
In order for the agency to have an effective risk assessment program, related activities
within the agency need to be coordinated with an emphasis on the technical staff or scientist
level not just upper/middle management level. This is especially important as the agency
develops activities oriented towards nonchemical stresses (Le.» wetlands protection, global
change, life cycle analysis, habitat loss, environmental quality criteria for geographic
initiatives, Environmental Monitoring and Assessment Program), The lisk Assessment
Forum should serve as a coordination point and implement this coordination through the risk
framework document and guidelines development (especially in the issue paper process).
Management needs to stress a cooperative rather than competitive atmosphere; there is more
than enough work to go around and much of the data and tools required for risk assessment
can be used throughout programs within the agency (see comments on need for S&D for
assessment methods).
It is not apparent that the agency has an effective strategy fon
A. Moving rapidly enough to consider non-chemictl stress areas (other agencies
such as FWS and BLM may provide useful experience)
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B, Securing R&D funds to support ecological risk assessment needs (the
development of assessment methods should be given high priority and RAF
should have formal input to the list of needs).
C, Building strong links among technical staff and among closely associated
activities such as EcoRisk Research, Wetlands Protection, the Great Lakes
Initiative, EMAP (esp, integration and assessment and indicators), Habitat,
Global Change, Such coordinated activities wiU allow development towards
the goal of holistic ecosystem risk assessment.
Cooperation needs to become an operational philosophy/ state^of-mind with both
technical staff and managers, and good cooperation needs to be rewarded,
The SAB commends the Forum staff for an excellent start in assembling the
Framework Document. The exercise is bringing the long-needed Agency focus to the
ecological risk assessment process. It should be recognized across the Agency for its future
impact on all activities and regulatory initiatives. Clearly its importance can not be
overemphasized. It should be explicitly stated that the framework can be applied to both
predictive and retrospective assessments. To ensure maximum applicability for Agency
needs, the Subcommittee feels that even more involvement should be encouraged of other
Agency staff and management. The framework wiU eventually evolve into guidelines which
will ostensibly be used to guide ecological research and regulatory initiatives across the
Agency. To be most effective, the Forum needs to expand to include representatives from all
segments of the Agency.
3,1,2 Framework Problem Formulation
The SAB applauds the inclusion of this phase in the ecorisk assessment process. It
provides the opportunity for up-front planning, problem scoping, conceptual model
development, and communication between the risk assessor and the risk manager. The
importance of this phase is often overlooked with the result that the risk assessment is not
properly formulated or focused. In order to facilitate communication, with the risk manager,
the problem formulation step should also consider alternatives to avoid or mitigate the risk.
The Subcommittee strongly endorses the use of a Conceptual Model in the Problem
Formulation Phase of ecological risk assessment. The development of the conceptual model
is a critical activity that influences both the risk analysis and risk characterization. The
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Subcommittee recommends that the Framework document Figure 2 be modified to emphasize
the central role of conceptual model development which is discussed in a later section. The
whole activity of Problem Formulation can be viewed as conceptual model development.
The remaining phases of the risk assessment process are built upon this component. It is
essential that it be formulated correctly and early in the process. Figure 2, page 10, of the
Framework Report needs to be modified to show that endpoint selection is an output of the
conceptual model not an input to the conceptual model.
The Subcommittee urges that the Framework Document be revised to specify that
development of the conceptual model should involve a multi-disciplinary team of engineers,
physical scientists, chemists and modelers, in addition to ecologists and biologists. The
conceptual model development should be the subject matter of a technical issues paper. The
paper should include: stressor identity, ecosystem boundary, ecological effects expectations,
and endpokts as proposed in the long range plan, and also include predictive and protective
parameters and specific data quality needs.
The Subcommittee recommends that the concept of public involvement be
incorporated into the Formulation phase. This is often critical to endpoint selection and
model development. The public is really EPA's primary client and their needs should be
considered in this phase.
3.1.3 Framework - Analysis
The SAB is pleased to see that the analysis phase considers not only exposure
(although they prefer the term stressor) and effects characterization, but it also includes the
interaction of the ecosystem (ecosystem characterization) on these two components. This
reflects the interaction between the ecosystem, the stressor, and the effects .which is often
overlooked in eeorisk assessment. The inclusion of this Interaction term strengthens the
ecological risk assessment approach.
The analysis phase of the framework contains two major compooents-exposure/stress
characterization and effects characterization. The preliminary results of the analysis phase
need to feed back to the conceptual model for refinement (perhaps show aa arrow back to
this phase).
The framework adequately outlines the general components of die risk assessment
process; however, the ability of the agency to perfopn the "ideal" type of quantitative risk
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assessment is dependent on the immediate initiation and appropriate funding of methods
development for risk assessment (including uncertainty analysis), especially in nontraditional
areas such as habitat loss and animal distributions. It is anticipated that exposure and effects
characterization is basically an outline of the tools the risk assessor has at his/her disposal
and includes both empirical and process modeling approaches. The ability to perform
exposure characterization for non-chemical stressors is a developing discipline that will utilize
Geographic Information Systems, remote sensing, and new ecological concepts coming out of
the discipline of landscape ecology such as habitat fragmentation and metrics to quantify and
detect change. Also, techniques to integrate or link models for multiple stressors with regard
to multiple endpoints is a critical need (i.e,, cumulative effects), A better understanding is
needed of the critical ecological processes that operate at regional scales. Applied models are
needed that can address these scales and can then easily be used in risk assessments,
Guideline development will not need ecosystem process models requiring input data that has
little likelihood of ever being available. The Subcommittee concurs that issue papers should
identify areas of critical research and added that the RAF should have direct input to funding
decisions.
The Framework, as written, is explicitly limited to physical and chemical risks and
does not address the risk of biological stressors. This is a serious omission - risks associated
with introduction or use of organisms are important ones, and are currently a major cause of
stress in many ecosystems. Further, with the growth of biotechnology, new kinds of risk
assessments will need to be conducted. Since the framework is intended to provide a broad
set of principles for future ecological risk assessments, it is important that it incorporate risks
associated with biological stressors,
Subcommittee members continue to be concerned that the tenor of the Framework
reflects a continuing emphasis on chemical risk assessment (e.g., dose-response relationships
and protection of individuals), that is not consistent with the Science Advisory Board's
recommendations nor those of the previous peer review panel workshops that the Agency
broaden its efforts on ecological issues, including physical habitat alteration, biodiversity, and
global change. The Subcommittee recognizes that the framework is intended to address the
full array of ecological risks, but believes the effort to adhere to the human risk assessment
paradigm has resulted in terminology and approaches that convey a more narrow approach
than is desirable. As just one example, there is the continued use of the terminology
"characterization of exposure". While the term "exposure* includes.biological, physical,
chemical and other stressors, apparently the term conveys only chemical toxicologkal
mechanisms of cause and effects to many scientists. In view of this strong perception and
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recommendations of previous peer reviews of the Framework which emphasized stressors,
both chemical and non-chemical, the Subcommittee generally believes that the term
"exposure" should be called * stressor exposure" to clarify that it is an assessment or
characterization of exposures to stressors with both chemical and non-chemical
considerations. For consistency, the SAB also recommends that RAF adopt the same
terminology for human health risk assessment since exposure to more- than one type of
stressor may occur.
The Subcommittee recommends that the terminology used in the Analysis Phase be
revised to be consistent with the concept of stressor characterization and stressor analysis to
avoid the implication that the risk assessment process is principally chemical oriented,
focusing mainly on individual toxicologies! endpoints. It is particularly important in this
phase because it is at this point that the stressor data are analyzed the most intensively,
Figures 1 and 3 in the draft Framework Document were inconsistent with that
recommendation. The figure implies that the risk assessment process separates the stressor
and effects data during the Problem Formulation and Analysis phases. In practice this is not
always the way the data are handled. A minor .change in the Framework is recommended.
s
It is also recommended that the data acquisition, verification and monitoring steps
(box) be incorporated in a more formal way into the three phases of the Framework (Figure
3). The Subcommittee believes that these steps are a critical part of the risk assessment
process. They also believe this is an iterative process that occurs at many points throughout
the risk assessment process and is integral to the process. The Subcommittee recommends
therefore that the data acquisition, verification and monitoring box be moved inside the lines
of the Ecological lisk Assessment box.
Ecological impacts caused by human activities, such as habitat loss,, result in major
environmental impacts for some specks and their populations. The interaction of humans
with their environment represents a serious risk to many ecosystems. Yet, this is as area that
is not extensively analyzed from the viewpoint of risk assessment and risk management. It is
recommended that the Agency give careful consideration to the development of risk
assessment procedures for impacts from human activities and review the Framework to insure
that it adequately incorporates non-chemical stressors. Them Is a serious need for society to
deal with the major risks to our environment for if we spend all our time studying minutiae
we may find the ecosystems we wish to protect have disappeared or has been drastically
modified.
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3.1.4 Framework - Risk Characterization
The Subcommittee supports the flexibility of the Framework Document to include
both qualitative and quantitative approaches to risk assessment. Greater recognition needs to
be made for the importance of integrated, regional (holistic) ecological risk assessments of
ecosystems. Guidelines must also clearly recognke and provide assistance for both predictive
and retrospective ecological risk assessments. The Subcommittee recognized that there are
many different kinds of risk assessments that are needed by the Agency ranging from simple
to complex. The Framework Document recognizes this need and allows use of a variety of
approaches ranging from the quotient method to very quantitative probabilistic risk
assessment methods. The guidance provided in the Framework Document on the use of
scientific judgement is important. Likewise, the Subcommittee endorses the weight of
evidence concepts outlined in the document. Inclusion of all these above considerations and
concepts allows flexibility yet provides important guidance to risk analysts.
3.1.5 Risk Management Interface
The risk assessor and the risk manager both have very complex and responsible roles
which have been repeatedly highlighted by the NEC and recent EPA Administrators. In their
roles, the assessors are supposed to deal with the relationships between stressors and effects,
including their uncertainty (with a clear indication as to whether these are protective,
predictive, prospective or retrospective risk assessments). The risk manager should
contribute to the development of the conceptual model and when the assessment is complete,
the risk manager should amplify the risk assessment to include political, societal, economic
and other considerations. The risk managers and assessors should define the risk and the risk
taker as the first step in each case and define their problem and select endpoints that can lead
to considerations of risk minimization.
The output of the Risk Characterization is fed to the Risk Management box.
Discussion of the significance of this step is addressed in a limited fashion in the framework
document. This Is clearly unacceptable. As written, the connection between assessment and
management are disturbing. The risk assessment process needs to be appropriately separated
from the risk management process, and there needs to be a safeguard that prevents the risk
manager from over influencing the outcome of the risk assessment process. However,
discussion is needed in this section to ensure readers that the output of the risk assessment is
indeed useful to the user group, i.e., risk managers. Without this consideration, there is no
check as to exactly when the assessment is complete or how well the process was done. The
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Subcommittee strongly recommends the addition of a page or two of text to fully discuss the
conceptual use of the assessment by the risk managers. In particular, the discussion should
address the balance needed between risk management and risk assessment.
3,1,6 Status of the Framework
At the time of the SAB review, the Subcommittee was advised that the Framework
Concept was evergreen, but that the Document would be published soon. During the
discussion at the review, the Subcommittee asked if RAF could make changes to the
framework, to reflect SAB comments on the figures, terminology, and introduction to the
document. Later, the Subcommittee was advised that the framework was published without
change. The Subcommittee believes that the Framework is an important document and
recognizes that it serves as both a starting point and a broad outline to be modified in the
future. The Subcommittee also believes that many EPA programs wil adopt the Framework
as the foundation for their guidance to staff in the states and EPA regions to perform
ecological risk assessments. Once programs develop such guidance, it will be difficult to
modify or correct the practices of the field staff and to advise them of changes. Therefore
the Subcommittee recommends that the RAF modify its Framework to reflect significant
comments from the SAB as soon as possible and further the RAF should develop a
mechanism, such as newsletter, to keep managers and staff in programs and field components
aware of evolving changes in the framework and the status of guideline development
3,2 Issue Papers
The Subcommittee judged the inclusioa of the Issue Papers concept as a valuable
adjunct to other components in the ecological risk assessment guideline program. It appears
to be an excellent format to address technical and implementation issues through the use of
expert panels in workshops. The Subcommittee strongly urges the Agency to develop the
technical issue papers presented in the charge as well as those identified below. Brief
guidelines should be developed that describe what should be included in each Issue Paper,
and case studies should be tightly linked to issue papas. A prioritization process should be
used for develop Issue Papers tint focus the most effort on the weakest areas so they can be
addressed by research early in the guidelines development process.
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3.2,1 Conceptual Model Development
As indicated in Section 3,1.2, this subject probably deserves an Issue Paper of its
own. The Issue Paper should discuss examples of conceptual models and show how they
affect the collection and evaluation of data. It should cover examples of both chemical and
non-chemical stressors (especially biological stressors) and discuss the types of inputs that the
risk manager should have in developing the conceptual model. Finally, the paper should
explain how the conceptual model was addressed by the risk assessment and discuss how it
could be modified by feedback from the risk assessment process.
3.2.2 Natural Ecosystem Variability
The Subcommittee recommends that the Forum consider the inclusion of an Issue
Paper delineating the difference between anthropogenic stressor effects and natural ecosystem
variability separate from the one proposed for ecological significance. Attempts to project
laboratory-derived fate and effects data into the real world are most typically frustrated by
the high intrinsic rate of natural variability seen in aquatic and terrestrial ecosystems. Subtle
effects of man-made stressors are often impossible to measure, given the magnitude of
changes in populations due to natural meteorological events, predation, and disease. A full
consideration of ecosystem variability and the detection of the significant strtssor impacts will
be very useful to the ultimate use and application of ecological risk assessment guidelines.
3.2.3 Data Acquisition Issue
It would be appropriate for data acquisition to be dealt with in an Issue Paper, The
Subcommittee viewed this subject as critically important as was evident by their previous
recommendation to move it plus verification and monitoring inside the analysis box. This is
a topic that requires team building and coordination both witMa the Agency (EMAP, Ecorisk
Research, and PemiitfReguJatoiy monitoring) and outside the Agency,
3.2,4 Ecological Risk Assessment and Environmental Impact Analysis
There is a fundamental need to clarify the relationship between risk assessment and
environmental impact assessment For the past two decades, widespread use of
environmental impact assessment, principally under mandates of the National Environmental
Policy Act, has led to an array of approaches and methods for predicting the environmental
consequences of various environmental stresses. Some of the concepts and unresolved issues
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in environmental impact assessment overlap ecorisk assessment; others do not. In some
cases, formal risk assessments are incorporated within environmental impact assessments.
Further, the terms "environmental impact* and "ecological risk" overlap, but are not
synonymous. Conceptually, the Environmental Impact Statement approach should provide a
valid ecological risk assessment which evaluated the relative risks of all alternatives to the
proposed project. The framework document does not address these important relationships.
Failure to do so creates confusion, and also may overlook important contributions to each
approach that can be made through closer interactions. For example, the alternatives may
identify ways to avoid risks or mitigate the impacts. The Subcommittee recommends
thorough exploration of these relationships in an Issue Paper.
3.2,5 Uncertainty
The Subcommittee recommends that this very important topic, which has already been
identified by the Agency as needing an issue paper, be explored and clearly set forth the
categories of uncertainty that result in environmental risk, including:
o Lack of basic scientific .information about cause and effect, and ecosystem
behavior
o Probabilistic behavior of natural systems, such as floods, droughts, or
earthquakes
o Probabilities of technological failure or accidents, such as nuclear accidents
o Uncertainties stemming from imprecision in sampling, toxicoiogical testing,
and analysis that ill contribute to uncertainty. - •
Each of these categories imposes different requirements on risk assessment. It is
important to clearly structure risk assessments to reflect these different causes of uncertainty,
and to convey the nature of the uncertainty/risk to the risk manager.
In their most general terms, assessments of ecosystems involve the evaluations of
Structural variables (e.g.: topography, soils, species present), Stale variables (e.g.;
population density, temperature, contaminant concentration), and Rate variables (e.g.:
population changes, climate changes). None of these are constants. It is imperative to
17
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differentiate their normal ranges from that which could be induced by external influences,
whether these be chemical, physical or biological in nature-
Many of the uncertainty issues cited here relate to an analysis of the different types of
uncertainty that are encountered in the natural variability of ecosystems, accuracy and
precision of measurements, and uncertainties introduced by the use of surrogate
measurements. The treatment of these uncertainties becomes critical during the risk
assessment phase. If the purpose of the assessment is the description of the present state of
the ecosystem or a prediction of the future fate of the ecosystem, then the assessment is
expressed in terms of central or most likely values with their associated uncertainties. If the
purpose of the assessment is to establish a level of protection, then the uncertainty is
converted to a bias applied to the stressor quantity (often in terms of uncertainty factors,
safety factors, or modifying factors).
3,2.6 Linking of the Issue Papers with the Case Study Papers
In the process of Guideline development the issue papers and case studies are
proposed to proceed on separate and parallel tracks. Actually, the Issue Papers will rely
upon case study data to develop the topics. Therefore, it is clear that they need to be linked
and coordinated (Figure 1). While this activity may not require an separate issue paper task,
the authors of issue papers must be assigned a communication task to ensure dialogue with
the case study authors. Outlines should be developed for both the issue paper and case study
task to ensure coordination between the issue paper authors and case study authors.
3,2,7 Highlight Research Needs
We recommend that there be a continuing and formal effort to inform the Office of
Research and Development of the research needed to fill identified gaps. Thus a separate
task should identify and summarize these needs based on all the issue papers. Some of the
subjects discussed by the Subcommittee included issues such as: (1) tools to assist in the data
assessment necessary to perform the risk integration, (2) risk integration phase data which
ranges from single quotient measurements to probabilistic assessment and complex model
evaluation, (3) probabilistic approaches to risk assessment, (4) complex model assessment,
and subjects that reflect an ever changing world. It is the research program that will provide
the long term foundation for ecological risk assessment.
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3.2.8 Predictive and Retrospective Risk Assessment
The Subcommittee recommends that RAF add in issue paper to discuss the
similarities and differences between predictive and retrospective risk assessments. This issue
paper could rely on the topology of EPA risk assessment needs, suggested earlier, and the
case studies. These are standard terms which appear in the pubEshed literature, along with
studies of an epidemiologieai nature.
3,3 Case Studies
3.3.1 Potential Benefits
The Subcommittee viewed the role of case studies as useful and crucial to the overall
strategy of the Ecological Risk Assessment Guidelines. In fact it is suggested that the
Agency should consider significantly expanding the number and types of case studies
proposed for inclusion in the program. A need also exists to expand on exactly how they are
to be used in the development of the guidelines. Many more case studies, some of which can
be quite simplistic, will add significantly to how well the guidelines will apply to the wide
range of issues faced by the Agency. Better use of existing, published literature will also
simplify the effort and minimi2e potential for redundant effort. This is also an activity that
can highlight some of the useful assessment methods developed under the National
Environmental Policy Act.
It is not clear to the Subcommittee how the case studies are going to be specifically
used in the ultimate development of Risk Assessment Guidelines. The Subcommittee feels
that they have much to offer by identifying the types of risk assessments-performed by EPA
and other Agencies. The Subcommittee suggests that they may provide insight into the Muds
of ecological guidelines needed. However, since they are based on current and old issues
faced by the Agency, they may not represent the emerging issues challenging the Agency. A
careful balance must maintained between using case studies to identify the types of risk
assessment guidelines needed and the evolution of EPA's risk assessment activities in the
future,
Some of the case studies, e.g. the Chesapeake Bay study, ire data intensive and
costly, and therefore not routine. These studies should not be suggested to be the norm.
Nevertheless, these studies can be used to establish the relationship between data-rich and
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data-poor studies. The data-rich studies can be retrospectively decomposed into partial data
poor studies which can then be assessed with respect to their power to predict the actual
findings in the data-rich studies.
The RAF should develop a typology from the case studies and Issue Papers of the
types of risk assessments that the Agency will need to prepare. Once this is available, the
RAF may develop guidelines to address the specific categories of risk assessments that the
Agency will need to address. Such an approach would guide the risk assessor through the
steps in the context of the particular issues they need to address (e.g., cumulative impact
analysis which may be appropriate for habitat loss assessments may have different guidelines
from the Premanufacturing Notice assessment for TSCA).
3,2.2 A-ddMonai Case Studies
The Subcommittee developed the following list of potential case study subjects that
should be considered.
o Biotechnology
o Radionuclides
o Programs that calibrate predictive laboratory data with real world ecosystem
data
o Biotic stressors, introduced species and loss of species diversity
The Subcommittee concurs with the RAF selection of the following case study topics
they should be closely coordinated with to assure they meet the needs for examples from the
issue papers:
o Evaluation of ecological resources
o Habitat loss and disruption
o The irrigation and drainage program (in addition to the Kestersoa Wildlife
Refuge example proposed)
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Toxic Substances Control Act Premanufacturing Notices (additional examples
would be useful) and test rules for pesticides under the Federal Insecticide,
Fungicide, and Rodenticide, Act (these could focus on cumulative effects and
non-target wildlife populations)
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4. SUMMARY OF RECOMMENDATIONS
a. The Subcommittee believes that the ultimate success and usefulness of the Agency's
Ecological Risk Assessment Guideline program would be improved if the Framework
document and implementation strategy considered incorporating the items discussed in this
report. The Subcommittee also feels that the RAF should plan on periodic reviews and
updates of these documents,
b. The Subcommittee recommended that several additional issue papers be developed for
issues which will affect how well EPA can perform ecological risk assessments; these include
conceptual model development and natural ecosystem variability as distinct papers and new
topics for data acquisition, ecorisk research needs and a comparison of ecorisk assessment
with environmental impact analysis. The Subcommittee also recommends that EPA establish
a priorities to assure that issue papers are developed for the areas of greatest uncertainty first
so they may be addressed by research early in the guidelines development process,
c. The Subcommittee strongly supports the use of case studies and recommended that the
EPA significantly expand the number and type of case studies to illustrate the applicability of
risk assessment across the Agency.
d. The Subcommittee recommended that the Framework should define the potential issues
for the development of guidelines such as their nature, scope, intent, structure, and use. This
revision should be done as soon as possible so that it can affect the development and planning
of the intermediate steps (issue papers and case studies) leading to guidelines.
e. The Subcommittee strongly endorses the use of a conceptual model in the formulation
phase of ecorisk assessment and recommends that the Framework document Figure 2 be
modified to emphasize the central role of conceptual model development. The Subcommittee
also urges that the Framework Document should indicate that development of the conceptual
model needs to involve a multi-disciplinary team of engineers, physical scientists, chemists
and modelers in addition to biologists and ecoiogists. The Subcommittee recommends that
the concept of public involvement be incorporated into the Formulation phase, ft is also
recommended that the data acquisition, verification and monitoring steps (box) be
incorporated in a more formal way into the three phases of th« Framework (Figure 3).
f. The Subcommittee continues to be concerned that the tenor of the Framework reflects a
continuing emphasis on chemical risk assessment, that is not consistent with the Science
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Advisory Board's recommendations. The Subcommittee believes that the term "exposure"
should include the concepts of exposure to both chemical and non-chemical stressors. The
Subcommittee recommended that the terminology used in the Analysis Phase be revised to be
consistent with the concept of characterization of the exposure to stressors and stressor
analysis to avoid the implication that the risk assessment process is principally chemical
oriented, focusing mainly on individual lexicological endpoints. They also recommended that
the same term, stressor-exposure assessment, be used for human health risk assessment.
g. The Subcommittee recommends that the framework discuss the use of risk assessments by
risk managers and the balance between risk assessment and risk management.
h. The Executive Committee proposed and the Subcommittee concurred that the concept of
ecological risk assessment should include human health risk assessment, build upon the
human health model for species risk assessments, and harmonize the two approaches.
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APPENDIX 1. COPIES OF FIGURES 1-3 CITED FROM THE "FRAMEWORK FOR
ECOLOGICAL RISK ASSESSMENT" EPA/630/R-92/001
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Discussion
Between the
Risk Assessor
and
Risk Manager
(Planning)
Ecological Risk Assessment
PROBLEM FORMULATION
A
N
A
L
Y
S
1
S
Charac
Exp
te
or
OS
i
rizaton ' Charac
1
>ure ECQ.
1 Efi
1
;e
of
o?
ei
rization
jical
^s
v 4>
RISK CHARACTERIZATION
Daia Acquisition; Verification and Monitoring
t
i
Discussion Between the
Risk Assessor and Risk Manager
(Results)
i
Risk Management
J
Figure 1. Fram«woric for Ecological Risk Assessment
A-l
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PROBLEM FORMULATION
s
ANALYSIS
\
RISK CHARACTERIZATION
\
\
\
s
Discussion
Between the
Risk Assessor
and
Risk Manager
(Planning)
Stressor
Characteristics
Ecosystem
Potentially
at Risk
Endpoint
Selection
Assessment
Measurement
Conceptual
Model
Ecological
Effect*
a
o
^3
a
o
3
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a
3
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o
a"
ANALYSIS
Problem Fbnaulaion
A-2
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PROBLEM FORMULATION
ANALYSIS
"V
RISK CHARACTERIZATION
\
PROBLEM FORMULATION
Characterization of Exposure
Characterization of Ecological Effects
Stressor
Characterization:
Distribution or
Pattern of Change
I
Ecosystem
Characterization;
BiotiC
Abiotic
Exposure
Analysis '
fft
Evaluation
of Relevant
Effects Data
Ecological
Response
Analysts
Strtssor-Responso
Profile
RISK CHARACTERIZATION
Figures. Analysis
•*•**•
Data Acquisition; Ve
cation and Mon
ng
A-3
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Distribution List
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