SEPA
United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
April 1989
DRAFT
Protecting the Environment:
A Research Strategy for the
1990s
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Cover ArtworkProvided by the Environmental Research Laboratory, Corvallis. Oregon.
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April 1989
Draft
Protecting the Environment:
A Research Strategy for the 1990s
United States Environmental Protection Agency
Office of Research and Development
Washington DC 20460
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CONTENTS
Foreword iii
Executive Summary 1
Ecological Risk Assessment 19
Human Health Risk Assessment 33
Risk Reduction 47
Exploratory Grants and Academic Research Centers 61
Appendix A
Exposure Assessment - A Cross-Cutting Issue 63
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FOREWORD
Mounting evidence suggests that we are facing a new generation of environmental
problems - problems that threaten not just isolated areas, but global ecological resources;
not just the health of certain individuals, but our ability to sustain life on this planet.
Coping with these problems will require a fundamental change in our approach to
environmental protection. We must develop the capabilities to anticipate and prevent
pollution, rather than simply controlling and cleaning it up after it has been generated.
The tools with which we protect our environment - policy, education, regulation, and
technology - are grounded in the knowledge and understanding provided by environmental
research. As the federal agency charged with protecting our environment, the U.S.
Environmental Protection Agency (EPA) has conducted environmental research since its
inception in 1970. However, this research has generally been designed to fulfill EPA's
immediate regulatory needs. It is inadequate for addressing the critical, long-term, system-
wide environmental problems we now face.
There are many basic questions that we cannot answer now and will never be able to
answer without fundamental changes in our national environmental research agenda:
What is happening to our ecosystems?
How quickly are the changes occurring?
Are we causing irreversible damage?
What are the impacts of these ecological changes on human health?
This document describes an innovative new research program proposed by EPA to
provide the knowledge essential for addressing the environmental issues of the future. The
proposed program would integrate EPA's current basic research and expand it into critical
new areas. It would enable EPA to attract and retain leading environmental scientists and
policy makers. And it would generate the information we need to develop effective
solutions to our mounting environmental problems.
Acting Assistant Administrator
Office of Research and Development
in
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EXECUTIVE SUMMARY
INTRODUCTION
About 30 years ago, we became conscious as a
nation that our local environments were
deteriorating: rivers, lakes, and estuaries were
dirty, our city air was unhealthy to breathe, and the
water unsafe to drink. The environmental
legislation enacted during the following years
reflected our perception of pollution as a relatively
discrete local problem: It charged EPA with
controlling the pollution generated by individual
sources.
This "end-of-the-pipe" approach has successfully
enhanced the quality of many local environments.
However, despite these improvements, we now face
another level of environmental deterioration far
more ominous for our future than any end-of-the-
pipe problem: Continuing, persistent, and
cumulative pollution, from sources large and small,
controlled and uncontrolled, is gradually eroding the
fabric of our ecosystems that form the basis for life
on this planet:
In the eastern U.S. and many other areas of the
world, some evergreen forests have died and
certain lakes no longer support fish.
Stratospheric ozone, an essential part of the
atmosphere that sustains our life, is gradually
becoming depleted.
Our estuaries are becoming increasingly
polluted, with increased occurrence offish kills
and "toxic tides."
We are adding "greenhouse gases" to our
atmosphere, increasing the chances that we may
cause major climatic changes and the resulting
ecological and public health effects.
An increasing number of marine mammals,
including porpoises and whales, are diseased or
dying.
Addressing this new generation of
environmental and public health problems will
require a major shift in our overall approach to
environmental protection, and in our strategy for
generating the knowledge necessary to create and
implement environmental protection programs. The
EPA, as the federal agency responsible for
protecting our environment, must take the lead in
responding to this new challenge. Yet, it cannot
develop solutions without understanding what is
happening to our environment and why.
In a recent report (Future Risk: Research
Strategies for the 1990s, September 1988), the
Science Advisory Board (SAB) called research "the
most fundamental of the tools that promote
environmental quality." It recommended that EPA
"reshape its strategy for addressing environmental
problems in the next decade and beyond" and "plan,
implement, and sustain a long-term research
program" to support this new strategy.
In response, senior scientists and engineers in
the Office of Research and Develoment recently
reevaluated the Agency's environmental and health
research programs. They looked at the basic
research EPA is currently conducting and asked
what changes would be needed to ensure that we
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will have the fundamental scientific information
needed to formulate solutions to future
environmental problems.
Based on their recommendations, we are
proposing a major new "core" research program,
described in this document, to generate knowledge
essential to all areas of environmental decision-
making, not just the immediate and individual
regulatory needs of EPA's program offices. This core
research program will require not only
strengthening and expansion of existing efforts, but
substantial new initiatives in critical areas we have
neglected far too long. Also, it will require a
commitment to sustaining long-term research
projects that may take years to complete, and to
maintaining a steady core of expertise and resources
that will provide the continuity essential for
effective basic research. Major priorities of the
program are, in order of priority:
Research and development of a nationwide
integrated Environmental Monitoring and
Assessment Program (EMAP) to monitor the
baseline condition of and trends in our
ecosystems.
Long-term research to develop new tools and
strategies for pollution prevention, including
mechanisms to involve industry, state and local
governments, communities, and individuals.
Development of a national data base on the
extent and nature of human exposure to
pollution in the U.S.
Substantially increased support for the growth
and maintenance of an academic environmental
research community.
Increased effort to understand the relationship
between health and multiple exposures to low
levels of many different pollutants.
We estimate that approximately 25% of our
current $400 million research effort addresses
fundamental issues applicable to core research. We
are proposing to integrate this research and expand
it to create a new program devoted to core research.
This is consistent with the SAB's recommendation
in its September 1988 report that EPA's total R&D
efforts double over the next five years.
Many other agencies and institutions are
currently conducting environmental and health
research. In implementing the proposed program,
we will coordinate and cooperate with these groups
to seek the maximum yield from the collective
federal investment in these research areas.
The proposed core research program consists of
four parts:
Ecological risk assessment.
Health risk assessment.
Risk reduction.
Exploratory grants and research centers.
The two risk assessment components are designed to
help EPA evaluate the risks that environmental
contamination poses to our ecosystems and our
health. This knowledge will guide the Agency in
designing strategies to anticipate and reduce these
risks using the technologies and ideas generated by
the risk reduction research. And, an expanded
investigator-initiated grants program is proposed to
ensure the continued strength of this nation's
academic environmental research efforts.
The key elements of the proposed program are
presented in this executive summary. The
subsequent chapters provide additional detail, and a
separate chapter on exposure assessment shows how
exposure related research in each of the core areas
interrelates. Charts at the end of each section show
the budgetary resources required to implement the
proposals.
The program, in conjunction with the research
activities of other agencies, will help us to:
Redirect our efforts towards preventing rather
than cleaning up pollution.
Understand how pollution is degrading our
environment and affecting our health.
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Monitor the status of our ecosystems and our
exposure to pollutants.
Anticipate problems by predicting the health
and environmental effects of a changing
chemical climate.
Evaluate the effectiveness of our environmental
protection programs.
In the words of the Science Advisory Board, "Our
success at protecting public health and
environmental quality in the modern world will be
measured by the extent to which we understand and
manage those human activities that can affect the
environment both for better and for worse... .The
longer we remain ignorant of environmental
problems and their possible solutions, the greater
the risk of adverse consequences to human health
and the environment."
The proposed program will provide the
knowledge and understanding we will need to wisely
manage our rich and vital environmental legacy in
the coming decades. It will provide decision-makers
in the U.S. and abroad with the tools and
information to make the difficult choices that will be
necessary in the years ahead. We fully recognize
that these proposals represent a significant national
investment in this time of fiscal austerity. However,
we believe strongly that without the advances this
program will make possible, we are forced to gamble
with our future: We would most likely implement
solutions that would ultimately be more expensive
and less effective than possible, and we would risk
causing widespread irreversible damage to the
environment that sustains our life.
CORE AREA 1: ECOLOGICAL
RISK ASSESSMENT
What is the Problem?
Ecological risk assessment is the scientific
process of evaluating the risk that pollution poses to
our environment. This process, and the supporting
research program, have traditionally been narrow in
scope: They have focused on evaluating the effects of
individual pollutants and discharges on a limited
number of species to provide the data needed for
regulation. Consequently, we lack the base of
information and resources needed to assess the
impact of system-level stresses we are now facing,
such as global climate change, destruction of our
wetlands and forests, eutrophication of coastal
waters, and acid precipitation. We simply don't
know:
What is happening to our ecosystems.
How quickly the changes are occurring.
Whether we have passed a threshold of
irreversible damage.
How we can effectively protect our ecosystems.
The ecological research program, summarized
below, will develop the information and
methodologies that the Agency needs to answer
these critical questions. Should this research not be
done, we will not know with any acceptable degree of
confidence the magnitude or location of ecosystem
changes; how to diagnose the causes of major
ecological disruptions; how to prevent harm from
occurring; or whether our risk reduction solutions
are adequate to protect ecosystems and the
necessary diversity of life on this planet.
What is EPA's Role?
Many Federal agencies conduct ecological
research that is critical to EPA decision-making.
However, none of these agencies has the mandate to
protect the environment as a whole. Rather, they
manage specific ecological resources, such as forests,
parklands, and wetlands. EPA is the only Federal
agency with the mandate to take a holistic view of
environmental problems. Therefore, it is
appropriate for EPA to take the lead role in
developing our nation's core environmental research
program, in cooperation with other agencies and
institutions that are also conducting environmental
research.
What are We Proposing?
The core ecological research program is designed
to provide the scientific basis for protecting
ecological resource systems from environmental
pollution. It represents a major new initiative in
ecological risk assessment: the assessment of risk
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not just to individual species, but to all levels of
biological organization. Key aspects of the program
include:
An intensive initial effort to define the types of
ecosystems at risk and to develop measures to
indicate the condition of these systems.
Creation of a nationwide program to monitor the
status of and trends in our ecosystems.
Periodic reporting on the condition of
environment and how it is changing.
Long-term research to improve our
understanding of how pollutants affect the
structure and function of ecological resource
systems.
The program will help EPA answer questions in
four critical areas:
Which ecological resources are at risk?
What is the condition of the environment and
how is it changing?
To what levels of pollutants are our ecosystems
exposed?
How do pollutant exposures affect ecological
resource systems?
Key Elements of the Core Program
1. Which Ecological Resources Are at Risk?
To preserve our ecosystems, we must understand
what these ecosystems are, where they are, and how
they are being affected by pollution. As a first step in
the proposed core ecological research program, EPA
will conduct a multifaceted research program to:
Survey and classify the major ecosystems
according to their characteristics and how they
respond to pollution.
Define the extent and population of these
ecosystems.
Identify endpoints, such as hunting success,
tissue burdens, and nutrient cycling rates, that
indicate the condition of the various ecosystems.
Develop and apply sensitive methods to rapidly
screen and"fingerprint" multiple pollutants in
soil, water, air, and biota.
Select representative systems for further study
in other components of the core research effort.
This research will provide the basis for
developing a nationwide program, described below,
to monitor the status of our ecosystems. It will help
us determine where to monitor, what to monitor, and
how to interpret the results.
2. What Is the Condition of the Environment
and How Is it Changing?
Our current monitoring efforts are limited.
Typically, they tell us whether a particular effluent
is in compliance with current regulations, but
provide little useful information about the
ecosystem as a whole. Consequently, we don't know
how our ecological resources are being affected by
pollution and whether we are adequately protecting
them.
To remedy this situation, EPA will establish a
nationwide, integrated Environmental Monitoring
and Assessment Program (EMAP) to monitor the
condition of our ecosystems, including forests, lakes,
streams, and estuaries. EMAP will fill one of the
major gaps in current ecological risk assessments: It
will monitor the status and trends in representative
ecological resource systems that are at risk from
multiple environmental stresses. The data will
indicate whether any serious changes are occurring
in these systems and whether multiple or single
pollutants are causing the changes.
Central to EMAP will be annual reports on the
status of and trends in the environment. Every two
to three years, EMAP will publish integrated
assessments that interpret relationships between
exposure and ecosystem condition, and that assess
environmental quality in general.
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The program will answer several critical
questions:
What are the baseline characteristics that define
a healthy ecosystem and that can be used as a
standard against which to measure change?
How are our ecosystems changing?
Which pollutants are contributing to ecosystem
deterioration?
How accurately can models for ecosystem
exposure and effect predict reality?
EMAP will be developed over several years.
During the first year, a conceptual framework for
the program will be developed. This monitoring
framework and the selected indicators of conditions
will be tested and refined in several pilot studies.
Then EPA will begin to phase in fully operational
monitoring networks on an ecosystem-by-ecosystem
basis.
Implementing EMAP will require creating the
data base capability to effectively manage, analyze,
and regularly report the data, and developing the
scientific and technological basis to support the
monitoring. EPA will make maximum use of
existing data and will coordinate with other
agencies now doing ecological resource monitoring.
EMAP will alert us to potential large-scale
ecological changes, so that we can take action to
prevent them from developing into disasters. The
program will also supply a rich data base with which
to evaluate the effectiveness of our environmental
policies and regulations in safeguarding our
environment.
3. To What Levels of Pollutants Are Our
Ecosystems Exposed?
Resource limitations make it impractical to
monitor all ecosystems. Therefore, to answer this
question, we must be able to model how pollutants
are transported through the environment from their
source to the ecosystem. Models make it possible to
assess exposure without frequent and extensive
direct measurement of pollutant levels, and they
help us to predict and reconstruct exposure.
The models EPA currently uses are inadequate
for assessing ecosystem exposure. In particular they
are seriously limited in their ability to assess the
fate and transport of pollutants through ecosystems.
The proposed program will conduct research in
several areas to develop and validate models for
evaluating exposure at the ecosystem level.
Fate, Transport and Uptake of Pollutants. Our
lack of knowledge about how pollutants and
pollutant complexes are transformed by
biological, chemical, and physical processes as
they travel through the environment severely
limits our ability to develop accurate exposure
models. Research will be conducted to fill this
gap and to investigate factors that influence how
pollutants are taken in at the point of exposure
(e.g., bioaccumulation, predation,
biomagnification).
Biomarkers. Biomarkers are characteristics
(e.g., biochemical, biophysical, or physiological
changes) within an exposed system that indicate
the degree of exposure to a specific pollutant or
stress. They make it possible to determine
exposure retrospectively and to validate models.
Biomarker research has only recently been
made possible by advances in biological and
chemical sciences. The proposed research
program will capitalize on these advances to
identify biomarkers that could be used as
sensitive and accurate indicators of exposure.
(See also the discussion of biomarkers under
Core Area 2: Human Health Risk Assessment.)
Field Evaluation. Once the exposure models
have been developed and potential biomarkers
identified, they will be validated in the field by
comparing their predictions with real-world
exposures.
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4. How Do Pollutant Exposures Affect Our
Ecosystems?
At present, we have little idea how ecosystems
as a whole are affected by environmental stresses
such as pollution. There are many reasons for this
critical knowledge gap:
Much of our current dose-effect data comes from
small-scale experiments that do not capture the
complexity and sensitivity of ecosystem
interactions and therefore tell us little about
potential system-wide effects.
The results of field studies usually can't be
extrapolated to other systems.
9 We don't understand basic environmental
processes that affect a pollutant's fate and
activity within an ecosystem.
Developing models to predict how pollutants and
other stresses affect entire ecosystems, rather than
simply isolated components, will require major
advances in our state of knowledge. The core
program will study responses at all levels of
biological organization, from the biochemical level
to system-wide responses, to develop models that can
predict effects at these levels. This element of the
core program will have several components:
Using Chemical Structure to Predict Activity.
Quantitative Structure-Activity Relationships
(QSAR) is a technique that uses computational
chemistry to predict a chemical's environmental
activity (bioaccumulation potential, toxicity)
based on its structure. Under the proposed
program, EPA will develop QSAR capabilities
by identifying key structural properties that
make chemicals hazardous. (See also the
discussion under Core Area 2: Health Risk
Assessment for a different application of this
technique.)
Extrapolating Laboratory Data to Ecosystem
Effects. Most of EPA's ecological risk
assessments to date have been based on results
of toxicity tests in individual plant and animal
species that are not useful for predicting system-
wide effects. This research component would
investigate new laboratory tests that could be
used to indicate ecosystem effects.
Evaluating the Effects of Pollution on
Populations,Communities, and Ecosystems.
Natural populations can be devastated by long-
term, indirect, and cumulative impacts of
pollutant exposure that cannot be predicted
based on observations in a laboratory. The core
research program will develop, refine, and
validate models for assessing the effects of
exposure at the population, community, and
ecosystem levels. This will require identifying
populations and communities most likely to be
affected, identifying endpoints to measure
response, and understanding the environmental
parameters and community characteristics that
influence response.
Comparing the Effects in Different Species. This
area of research will help scientists use data on
effects in one species, population, or community
to predict effects in another species, population,
or community. The work will focus on gathering
the exposure and response data necessary to
develop models for predicting effects in various
species and at different organizational levels.
These topics are discussed in more detail in
Chapter 1: Ecological Risk Assessment. Figures
which indicate current and projected resources for
core research activities follow this Executive
Summary.
CORE AREA 2: HUMAN
HEALTH RISK ASSESSMENT
What is the Problem?
Environmental pollution - the by-product of our
technologically advanced society - is taking a toll on
our health. The National Institute of Medicine
recently estimated that a significant part of the $400
billion spent annually in the U.S. on health care is
attributable to environmental pollution. Yet we still
understand very little about how and to what extent
environmental contaminants are affecting our
health.
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Environmental health research at EPA has
historically focused on assessing the health risks of
single chemicals. Based on this research, we have
successfully reduced exposure to several important
pollutants, including lead and other criteria
pollutants, that clearly pose a risk to human health.
But this is only part of the problem. In reality, we
are exposed to a wide variety of contaminants in our
air, water, soil, and food.
EPA's current approach to health research is
insufficient to understand and mitigate these
complex real-world exposures: Because of the
pressing needs of the program offices to fulfill EPA's
immediate regulatory responsibilities, basic
scientific issues that require a commitment to long-
term research have been neglected in favor of short-
term studies. Consequently, our ability to protect
public health has been compromised. For example:
We don't know the real levels of many
environmental pollutants to which we are being
exposed.
Most of our health effects information is based
on short-term exposures of laboratory animals to
high levels of single pollutants. We are still
unsure how this relates to the low-level, varied
exposures that we typically experience in our
daily lives.
We are not sure how accurately effects in
animals predict effects in humans, even though
most health risk assessments are based on
animal data.
We don't have the necessary information to
understand how mixtures of chemicals are
affecting our health.
We don't understand the basic biologic
mechanisms by which pollutants cause their
effects.
We have focused on cancer-causing chemicals,
and paid relatively little attention to
environmental causes of other health problems
such as heart disease, lung disease, behavioral
effects, and reproductive and development
effects that are of major concern to the public.
What is EPA's Role?
Many Federal agencies conduct or support
environmental health research, including the
National Institute of Environmental Health
Sciences, the National Cancer Institute, the Agency
for Toxic Substances and Disease Registry, and the
Centers for Disease Control. EPA has the primary
responsibility among these agencies for
understanding the effects of low concentrations of
pollutants to which people are typically exposed, and
for mitigating these exposures to protect public
health. In this capacity, EPA occupies a unique
niche at the interface of basic and applied science.
EPA's understanding of real-world needs can help
fashion a productive basic research program.
Similarly, through its involvement in basic
research, EPA can apply developments at the
cutting edge of science to make our environment a
healthy place to live.
What are We Proposing?
The proposed program will develop tools and
knowledge to enable us to understand how
environmental exposures are affecting our health
and what we can do about them. It will provide
sound data, improved methods, and validated
models that will help us to assess the status of public
health, identify potential problems, develop risk
reduction programs, and evaluate the efficacy of
these programs.
A significant portion of EPA's current
environmental health research program is directed
towards core activities. The proposed program would
strengthen these existing efforts and add critical
new areas. In particular, the program would
considerably increase the funding in the assessment
of human exposure. It would:
Determine, on a national basis, the exposure of
humans to pollutants.
Increase our understanding of the mechanisms
of environmentally induced noncancer health
effects.
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Assess the hazards of new environmental
agents, such as bioengineered organisms, UV
radiation from stratospheric ozone depletion,
alternative fuels for motor vehicles, and mineral
fibers used to replace asbestos.
Investigate the human health effects of exposure
to multiple chemicals.
Develop biomarkers to estimate exposure and
effects of exposure.
Incorporate into the risk assessment process a
consideration of not just whether a chemical
causes an effect, but how severe that effect is.
Base risk assessment on the dose delivered to
the vulnerable tissues in the body, rather than
on the amount of pollutant we are exposed to
before it enters the body.
As discussed below, the program will help us
answer some basic scientific questions essential to
enhancing our ability to protect public health:
How can we detect environmental agents that
pose hazards to human health?
To what extent are human populations exposed
to pollutants?
What happens to pollutants once they enter the
body?
What health effects do environmental exposures
produce?
Key Elements of the Core Program
1. How Can We Detect Environmental
Agents that Pose Hazards to Human
Health?
Determining which contaminants threaten
human health and what effects they cause is the
fundamental basis for risk assessment. This area of
research - hazard identification - has historically
been a focus at EPA because of its applicability to
regulatory needs. The core program will focus on
developing methods for detecting and characterizing
environmental agents:
Developing Methods to Screen and Characterize
the Effects of Pollutants. This is a dynamic
research area that must continually incorporate
advances inbiomedical sciences. EPA will
continue to develop methods that will allow us to
rapidly screen large numbers of chemicals and
chemical mixtures to identify those that are
most hazardous. EPA will significantly expand
its efforts to develop and refine methods for
detecting noncancer effects, including damage to
the nervous system, immune system, liver,
heart, and reproductive system.
Using Chemical Structure to Predict Activity.
The study of structure-activity relationships
(SAR) allows scientists to predict the effects
(activity) of chemicals based on their molecular
structure, and to understand how pollutants
cause their effects. Currently, our ability to use
this tool is limited to particular chemical groups.
If sufficiently refined, SAR could provide a
powerful alternative to testing. The proposed
program would expand SAR research to include
a broader spectrum of environmental
contaminants and biological endpoints.
2. To What Extent Are Human Populations
Exposed to Pollutants?
Past research efforts have largely neglected this
question. Consequently, we know little about how
our population as a whole is exposed to pollutants.
How many pollutants are we exposed to? Which
ones? At what levels? How widespread is exposure?
What conditions increase or decrease exposure? The
research described below represents an innovative
program to help us answer these critical questions.
It will provide a much-needed scientific basis for
guiding hazard identification and health effects
research, and for suggesting new ways of managing
exposure to minimize the overall public health
threat. This research area will be substantially
expanded in the proposed program, with the long-
term goal of establishing a national human exposure
data base that can be used to answer questions about
exposure and to develop and validate models.
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Model Development. When direct measurement
is not feasible or practical, we must use models
to estimate human exposure. Models are useful
for reconstructing past exposures, estimating
current exposures, and predicting future
exposures. Human exposure models require
information about how the chemical is released
and transported in the environment, and about
human behavior and activity patterns that
influence exposure. Research will be conducted
in several areas to develop and validate models:
- Fate Studies. Studies will be conducted to
understand how pollutants move through
the environment from the point of release to
the point of human exposure.
- Media Monitoring. Real-world monitoring of
pollutants in environmental media (air, soil,
water) has been greatly neglected over the
past decade and has become a critical gap in
model development. This area will be
considerably strengthened in the new
program.
Population Activity Patterns. Knowledge of
human activities related to chemical
exposure is another major gap in our ability
to predict real-world exposures. The
proposed program would initiate research in
this critical area.
Model Validation. Models must be validated
during their development by comparing their
predictions with real-world exposures. The core
research proposes that the Agency create an
integrated, centralized exposure model
validation program.
Direct Measurement/Personal Monitors. Human
exposure can be measured directly, while it is
taking place, using devices called personal
monitors. Coupled with chemical "fingerprints"
of various emissions, these measurements can
substantially improve our ability to determine
what sources are causing exposure in the real
world. Current instrumentation can measure
only several dozen chemicals. The proposed
program would develop instrumentation to
measure many other chemicals, and would
develop a large data base of direct
measurements for use in answering questions
about priorities for corrective action and in
developing and validating exposure models.
Biomarkers. Biomarkers are specific
biochemical, genetic, or other physiological
changes within an organism caused by a
pollutant. They provide sensitive, specific
methods for measuring exposure and
characterizing effects. However, because the
development of biomarkers is at the cutting edge
of science, few biomarkers are currently used
routinely for estimating exposure. Scientific
advances in the next several years are likely to
provide new and increasingly sensitive
biomarkers. Under the proposed program, EPA
would substantially increase its research in this
area to identify useful biomarkers and
determine the relationships between biomarker
levels and absorbed doses. The goal of this
research would be to develop inexpensive,
hopefully noninvasive tests to measure exposure
and absorption of various chemicals.
3. What Happens to Pollutants Once They
Enter the Body?
A major area of uncertainty in risk assessment
today is what happens to a pollutant once it enters
the body. Where does the pollutant go in the body?
How much stays in the body and how much is
excreted? How much of the chemical is broken down
to metabolites? Where do the metabolites end up,
and are they more or less toxic than the original
compound? Because we usually cannot answer these
questions, we tend to regulate chemicals based on
the concentration to which we are exposed, not on
the dose that actually reaches tissues vulnerable to
damage (the "delivered" dose). This introduces a
level of uncertainty into risk assessments.
Currently, very little research is being done in
this area. The proposed program will conduct studies
to help us understand how environmental chemicals
are transported and transformed within the body,
and will use this knowledge to develop
pharmacokinetic models that will allow us to
estimate the delivered dose under varying exposure
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conditions, and to estimate historical and current
exposure.
4. What Health Effects Do Environmental
Exposures Produce?
Our ability to answer this fundamental question
is limited because of many gaps in our scientific
knowledge: How do pollutants cause effects? How do
mechanisms of disease and repair influence the
health outcome of environmental exposures? If a
substance affects experimental animals, will it also
affect humans? If a substance causes an effect at
high experimental doses, will it also cause effects at
low environmental exposures? To address these
gaps, EPA proposes to develop biologically based
dose-response models, and biomarkers, as described
below.
Biologically Based Dose-Response Models.
These models are used to predict human health
risks under realistic exposure conditions. EPA
will develop biologically based dose-response
models based on data from a wide variety of
sources and studies:
- Pharmacokinetic models, described above, to
elucidate the fate of environmental agents in
the body.
- Pharmacodynamic models, which provide
information about the response of the body
to these agents.
Inter- and intraspecies comparisons to
determine how animal data can be used to
predict the effects of human exposures.
Epidemiological research to enhance our
knowledge about effects in humans that
result from real-world exposures.
vffj*»»j*-»j^£af i^ studies to eluciciEtte ths bss'**
cellular and biochemical processes by which
chemicals cause their effects.
Studies to determine the effects of exposure
to chemical mixtures.
These data would be gathered for a wide variety
of effects, including cancer, as well as
developmental, pulmonary, reproductive,
neurotoxic, immunotoxic, and genetic effects. In
time, the models would be developed to predict the
effects associated with complex mixtures, as well as
individual pollutants. The ultimate product of this
effort will be more scientifically defensible risk
assessments for both cancer and noncancer
endpoints.
Biomarkers. EPA will also conduct research, as
described under the exposure section above, to
develop biomarkers for characterizing effects.
Research will focus initially on markers for
genetic effects and then expand to markers for
other effects, including immunologic,
neurologic, and reproductive effects.
These topics are discussed in more detail in
Chapter 2: Human Health Risk Assessment. Figures
which indicate current and projected resources for
core research activities follow this Executive
Summary.
CORE AREA 3: RISK
REDUCTION
What is the Problem?
Risk reduction converts assessment into action.
It includes any policies, technologies, or activities
we implement to protect ourselves and our
ecosystems from hazardous environmental
contaminants. EPA and industry have traditionally
focused on only one approach to risk reduction:
controlling end-of-the-pipe pollution. However, this
approach has a major disadvantage: It tends to
transfer pollutants from one medium to another - for
example, when the sludge from air pollution control
is disposed of on land. This reduces, but usually does
not eliminate, risk. Also, there is much we still don't
know about the performance, reliability, and cost of
many of the control technologies that we are now
using to reduce risk.
Pollution prevention offers a powerful risk
reduction alternative that is usually less costly and
more effective than end-of-the-pipe control.
However, as a nation we have largely neglected this
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alternative in the past. Consequently, much
research is needed to develop and evaluate new
technologies and process modifications, to create
strategies for pollution prevention, and to help us
develop the most effective means for educating and
motivating people and institutions to cooperate in
reducing the risks to our health and our
environment.
What is E PA's Role?
A major responsibility for risk reduction
research lies with industry. Therefore, a key
element of EPA's proposed risk reduction program is
to stimulate and work cooperatively with the private
sector. EPA also has a mission to support state and
local risk reduction efforts that go beyond EPA's
regulatory responsibilities, and to promote research
in the academic community. Finally, EPA must
provide leadership in fostering the communication
and cooperation between government, industry,
academia, and the public that will be essential for
effective development and implementation of
comprehensive risk reduction solutions.
What are We Proposing?
The core research program will significantly
expand EPA's capability to develop and promote risk
reduction activities at all levels and in all
environmental media. The program will help us to
understand where pollutants are coming from, so
that we can know how to focus our risk reduction
activities. The program will provide much-needed
research into how we can promote the changes
needed in industrial processes and products to
prevent pollution. Core research will also help us
understand how we can educate and motivate
individuals and institutions to make the changes
needed to reduce risk. Finally, the program will help
us to develop more efficient and effective
technologies for controlling the pollutants that we
do generate. Risk reduction research will be
significantly enhanced in many new areas that have
received limited attention to date: municipal and
medical solid waste, global climate change,
stratospheric ozone depletion, nonpoint source
control, indoor air pollution, and emissions from
alternative fuels. The proposed core research
program will help us answer questions in five
critical areas:
What are the sources of pollutants?
How can we prevent pollution?
How can we control the pollutants that we do
generate?
How can we involve people and institutions in
preventing and controlling pollution?
How can we anticipate and reduce emerging
risks?
Key Elements of the Core Program
1. What Are the Sources of Pollutants?
b
The information generated by the risk
assessment portions of the core program, described
earlier, will help us identify pollutants that pose
threats to human health or our ecosystems. To
reduce the risks associated with these pollutants, we
must know where they are coming from.
At present, we understand very little, on a
regional and national scale, about the overall scope
of pollution and waste generation in the United
States. How much pollution and waste do we
produce? What kinds? In what quantities? To what
extent is industry successfully reducing pollution?
The basic information gap hinders our ability to
mitigate pollution, particularly the widespread and
persistent pollution that comes from a variety of
sources. It also makes it difficult for us to anticipate
the pollution problems of the future and to evaluate
our success in reducing pollution.
EPA will conduct research to understand the
nature and rates of releases from point and local
emission sources such as industrial furnaces,
incinerators, and discharge pipes. The core program
will also study the chemical, biological, and physical
mechanisms that govern how various dispersed
sources, such as agricultural runoff, methane gas
from marshes, and natural vegetation, release gases
and particulates. Also, EPA will expand its efforts to
identify and characterize sources of indoor air
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pollution, such as heating devices, construction
materials, and household chemicals. Specifically the
research will help us understand:
What pollutants are released from particular
sources.
How pollutants change as they are released.
How various environmental and climatic
conditions affect the rate and type of emissions,
and the resulting contaminant levels.
To what extent treatment technologies, designed
to help us control pollutants, actually reduce
pollution rather than transfer contaminants into
other environmental media.
2. How Can We Prevent Pollution?
Pollution prevention has many advantages over
end-of-the-pipe control:
It often costs less, since there is less waste to
manage, and because recovered and recycled
materials have value.
It reduces the need for regulation and the
potential for liability.
It is effective not only for larger, distinct sources
of pollution, but also smaller, widespread
sources, such as agricultural pesticide runoff,
small business and commercial operations, and
residential wastes, where control technologies
are difficult to apply.
Preventing pollution requires three activities:
We must generate the technological knowledge and
tools for prevention. We must educate individuals
and institutions about these resources. And we must
motivate them to use these resources. The core
program will broaden EPA's research to identify and
evaluate pollution prevention technologies. It will
significantly enhance EPA's activities to
communicate its findings to industry, states, and
communities, and it will provide funds for basic
research to help us understand how we can motivate
people and institutions to change. The technology
development aspects of the proposed pollution
prevention research are described below. The
research to increase the national involvement in
preventing pollution is described below under 4:
How can we involve people and institutions in
reducing and controlling pollution?
There are three basic technological approaches
to preventing pollution: modifying industrial
processes, recycling, and changing product design
and use. EPA will conduct research in all three
areas. A major area of focus will be technologies
likely to be neglected by the industrial sector
because they apply to businesses, such as dry
cleaners, that are too small or too dispersed to
conduct their own research. The three core research
areas are:
* Modifying Industrial Processes to Reduce
Wastes. Examples of industrial process changes
that reduce the generation of pollution include
changing raw material feedstocks, redesigning
the process for higher efficiencies and yields, and
preventing leaks and spills. The key objectives of
EPA's core research program in this area are to:
- Develop standardized methods for assessing
waste reduction opportunities in various
industries.
- Conduct model waste reduction assessments
in key industries.
- Identify, demonstrate and evaluate in both
new and existing industrial processes
innovative methods for reducing pollution
generation, such as modifying the processes,
upgrading their maintenance, using
different raw materials, preventing spills,
and concentrating waste streams.
- Conduct pilot-scale research to establish
model pollution prevention processing
facilities.
- Identify and stimulate cross-industry
applications of innovative production and
processing technologies that reduce wastes.
Increased Recycling. Recovery, reuse, and
recycling are important ways in which
industries, communities, and governments can
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reduce pollutants and waste. Under the core
program, EPA will:
- Identify, demonstrate, and evaluate
strategies to increase the use of recycled
materials in products.
- Identify and evaluate new and innovative
uses for materials that would otherwise be
discarded as wastes.
- Evaluate the cost and performance of
various technologies to recycle, reuse, and
recover wastes.
Develop guidelines for model recycling
programs.
Changing Product Design and Use. Pollutants
can be reduced by eliminating toxic and
hazardous substances in products; increasing
product lifetime; and improving the durability
and repairability of products. EPA's core
research will:
- Analyze product lifetimes to identify
opportunities for reducing wastes associated
with individual products.
- Develop criteria for evaluating specific
products to predict their pollution loads.
- Evaluate the performance of products that
generate less wastes.
3. How Can We Control the Pollutants that
We Do Generate?
Pollution prevention activities will help us
minimize pollution, but there are many facets of
contemporary life, e.g. manufacture and use of
material goods and production of energy, which will
continue to generate some pollutants. For this
reason, technologies that enable us to effectively
control pollutants will continue to be an essential
component of risk reduction in the years to come.
EPA currently conducts research to develop and
test a variety of control technologies. This research
will be expanded under the core program to explore
the fundamental mechanisms that govern pollution
control technologies, to refine innovative
technologies that show great promise for control and
cleanup, and to evaluate new technologies based on
recent scientific and technological developments.
Areas of research under the core program will
include:
Understanding Combustion Processes. Many
different wastes are now treated by combustion,
but there is much that we still don't understand
about the process: What are the products of
incomplete combustion and how can we
minimize them? What happens to metals during
incineration? How do the characteristics of the
waste and the operating conditions of the
incinerator affect the type of gases and ash
created by the process? The core research
program will study the fundamental principles
of combustion and thermal destruction to
develop more efficient processes that minimize
adverse emissions. The use of catalytic devices to
destroy or prevent the generation of unwanted
by-products will be investigated. The program
will also investigate the kinds of emissions that
home heating devices such as woodstoves and
kerosene heaters produce, so that we can develop
effective controls for these emissions.
Using Microorganisms to Treat Wastes.
Biological processes, which use microorganisms
to degrade and detoxify wastes, have
successfully been used to treat sewage and
organic industrial wastes for many years. Now,
genetic engineering offers the potential for
creating organisms that could increase the
effectiveness of proven technologies and
revolutionize cleanup activities at spill and
hazardous waste sites. This research area is
expected to yield substantial benefits, but we
still have much to learn. Research will focus on
helping us understand how we can:
- Effectively release and disperse
microorganisms in the media to be treated.
- Promote the survival of microorganisms in
the field.
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Monitor the effectiveness of these processes
in treating wastes.
Physical Separation. This includes a broad
variety of processes to separate contaminants
from drinking water, wastewater, sludges, solid
wastes, and gaseous emissions. These processes
help to decrease the toxicity of the matrix, and
concentrate toxic pollutants. Under the core
research program, EPA will study the
mechanisms that influence the effectiveness of
the various physical separation processes in
order to improve the efficiencies and cost-
effectiveness of existing technologies and to
develop new technologies.
Using Chemical Processes to Treat Was tes.
Chemical processes are used to separate,
immobilize, and destroy a variety of
contaminants. Under the core program, EPA
will conduct research to:
- Enhance our understanding of how chemical
processes degrade a variety of contaminants
in soil.
- Study the environmental impacts of the
chemical treatment processes themselves.
- Investigate the chemical mechanisms that
influence the effectiveness of water
treatment processes.
- Investigate the chemical mechanisms that
can be used to stabilize and immobilize
contaminants in soils and wastes.
Containing Wastes. Containment technologies
use some form of barrier (e.g., tanks, drums,
sealants, protective clothing) to separate
harmful materials from the environment. The
program will investigate the physical and
chemical mechanisms associated with a broad
range of containment materials, and will
develop methods for monitoring the performance
of containment technologies. Research will focus
on one of the most critical containment
questions we face today: How effective are the
caps, liners, and immobilization/stabilization
technologies we are using to protect the
environment from landfilled waste? The
program will study how chemicals, microbes,
sunlight, subsidence, and other factors influence
effectiveness, which will help us to retard and
predict failure. The program will also
investigate mechanisms that influence the entry
and accumulation of indoor air pollutants, so
that we can develop cost-effective barriers to
reduce this pollution. Finally, containment
research will investigate the basic mechanisms
leading to the failure of underground storage
tanks.
4. How Can Vie Involve People and
Institutions in Preventing and Controlling
Pollution?
Risk reduction requires the participation of all
segments of our society: industry, government,
institutions, communities, and individuals. Under
the core program, EPA will provide leadership in
developing effective methods for educating and
motivating these various groups to implement risk
reduction strategies and technologies. Core research
will include technology and information transfer
techniques, as well as research to understand what
factors motivate people and institutions to change
their behavior.
Educating Our Nation. EPA currently uses
many approaches (publications, workshops,
training, expert systems, etc.) to deliver
scientific and engineering information to a
broad array of environmental users. Under the
core program, EPA will work together with
private industry, trade and professional
associations, state and local governments, and
academia to develop mechanisms for
disseminating information on risk reduction,
and evaluating the effectiveness of these
activities. Which audiences do we need to reach?
How can we reach them most effectively? What
kind of follow up is needed? EPA's contributions
to this national educational program would
include a pollution prevention clearinghouse,
and training and technical assistance through
seminars, conferences, computer-animated
graphics, video tapes, computer-assisted
instruction, and expert systems.
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Changing Behavior. Implementing risk
reduction technologies and strategies will
require major changes in individual and
institutional behavior. A major focus of the core
research program will be to study the factors
that influence and motivate change. The core
research program will study several basic
questions:
- How do people perceive risk and how can we
best communicate risk? Key topics will
include: methods for placing diverse risks in
perspective, how social and cultural factors
influence risk communication, and how to
present uncertainty.
- What factors influence an industry's
willingness to develop and utilize new
technologies? Core researchers will examine
the relative effectiveness of various
incentives and disincentives that influence
adoption and commercialization of new
technologies. Based on this research, EPA
will develop expert systems to assist the
technology developers to identify the actions
required for commercialization. These
systems should help reduce the time it takes
to get new environmental technologies into
the marketplace.
5. How Can We Anticipate and Reduce
Emerging Risks?
Trends in many different areas can indicate
societal changes that may cause future
environmental problems. As part of the core
program, EPA will develop a system for monitoring
technological trends (e.g., new manufacturing
processes and products) for their ability to affect the
characteristics and amount of production emissions.
EPA will develop methods for monitoring and
analyzing demographic, economic, infrastructure
(e.g., transportation), foreign trade, and other data
to aid in anticipating future environmental
problems. This information will be used to set
priorities for risk reduction research so that
strategies can be implemented as early as possible.
To date, EPA has identified several emerging
issues for study under the core program:
Municipal Solid Waste. We are rapidly running
out of landfill space to dispose of our refuse.
Research will be conducted to investigate
resource recovery options, and to enhance our
knowledge about the cost, performance, and
public acceptability of various options for solid
waste disposal, including incineration.
Global Climate and Stratospheric Ozone
Depletion. Core research will identify affordable
technological and nontechnological options for
reducing emissions of carbon dioxide,
chlorofluorocarbons, and other air pollutants
that contribute to ozone depletion and global
warming.
Indoor Air. Recently we have started to realize
that air within our homes and buildings may
sometimes pose a human health risk. The
problem appears to be increasing as buildings
are sealed off to conserve energy. EPA currently
has a modest program to identify the emissions
from construction materials. This program will
be expanded to identify emissions from
combustion appliances and household chemicals.
Using this information, a pollution prevention
and control program will be initiated to provide
mitigating guidance to the public.
Medical and Infectious Wastes. Careless disposal
of medical wastes has become a major concern in
recent months. The core program will evaluate
the efficacy of various transportation, handling
and disposal options.
Nonpoint Source Contaminants. A significant
portion of the pollution that is threatening our
ecosystems comes from innumerable, widely
dispersed nonpoint sources such as pesticide
runoff. The EPA will work cooperatively with
the U.S. Department of Agriculture, academia,
and the private sector to identify, evaluate, and
disseminate successful prevention technology
options to users.
Water Supply. As our population grows, we will
need new water sources, especially in arid areas
and areas of groundwater contamination. The
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core program will identify cost-effective water
treatment options so that we can reuse water,
reclaim contaminated groundwater, and create
alternative water supplies (e.g., desalinization).
The program will also evaluate approaches for
reducing water use.
Alternative Fuels. One way to reduce the risks
posed by air pollution would be to use
alternative fuels for heat and transportation.
Core research will be conducted to characterize
the emissions of potential alternative fuels, so
that we can evaluate the health and
environmental implications of making a switch.
Environmental Infrastructure. Our nation faces
a major problem with the aging and decay of its
infrastructure, including water delivery
systems, sewers, and wastewater treatment
plants. Core research will identify opportunities
for incorporating pollution prevention practices
as the infrastructure is replaced.
These topics are discussed in more detail in
Chapter 3: Risk Reduction. Figures showing current
and projected resources for this core area follow the
Executive Summary.
EXPLORATORY GRANTS AND
ACADEMIC RESEARCH
CENTERS
What is the Problem?
A recent study conducted by EPA indicates that
while many different departments and agencies
fund environmental research, no one agency
considers its mission to be general support of the
nation's environmental research community. In
fact, in fiscal year 1986 only about one percent of the
funds directed towards nonhealth environmental
research supported investigator-initiated grants.
The situation in environmental health research was
not much better. There is near universal agreement
that a large applied research program cannot be
sustained without significantly more support for
fundamental knowledge upon which the applied
program is based. This statement is based on a
wealth of experience with large Federal applied
research programs as diverse as defense, space,
medicine, etc.
The lack of grant support not only lets the data
base dry-up, it also results in the drying up of the
research personnel base. Researchers cannot risk
committing themselves (i.e., their careers) or their
graduate students to environmental research unless
there is a reliable source of funding available. At
present, there is none. This raises the specter of
shortages of technically competent environmental
researchers and managers in the future.
What is EPA's Role?
The investigator-initiated grants and academic
research centers we propose will not be limited to the
specific priorities and requirements of other
departments and agencies operating in the
environmental arena. Only EPA has the necessary
synoptic view of the interface between basic and
applied environmental science that led the SAB to
conclude in its recent report, Future Risks: Research
Strategies for the 1990s, that "... EPA must do more
to increase the amount and improve the quality of
the scientific and engineering talent dedicated to
environmental research."
EPA's former Administrator, Lee Thomas,
echoed the sentiments of the SAB in his January,
1989 planning guidance to the Office of Research
and Development. He noted that"... the Agency's
research program is at a turning point in its
evolution," and further, that "...With the recognition
of the critical state of the earth's environment, and
of our inability to understand the many changes
that are occurring, has come the realization that
EPA must be a scientific research agency as well as
a regulatory and enforcement agency." He concluded
that "EPA must provide the principal support for the
country's environmental research community," and
based his conclusion on two facts: (1) no one else is
doing it and (2) only EPA has the necessary breadth
of needs to support it.
What are We Proposing?
U.S. experience since World War II clearly
demonstrates that success in mounting large applied
research programs depends on stable, reliable
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support for individual researchers, largely in
academia. Environmental research grants:
Stimulate progress in fundamental knowledge
upon which the larger, applied program feeds.
Provide graduate and post-doctoral training for
the young scientists and engineers who will
become future environmental researchers and
managers.
Increase the probability of detecting
environmental problems earlier and the
methods to avoid or ameliorate them, thereby
significantly decreasing the cost of coping with
such problems.
We are proposing to create a significantly larger,
more stable source of funding for investigator-
initiated grants and to expand our support of
academic centers in those research areas which
require a definite commitment of time and money
not achievable through individual grants. In other
words, we are proposing that EPA become a reliable
partner with the academic environmental research
community. EPA will derive direct benefits from the
research performed by grantees while reaping the
indirect benefits of a substantially larger, more
vigorous, and more highly skilled community of
environmental research scientists and engineers.
From their ranks will come not only the knowledge
we will require to confront emerging environmental
challenges, but also the environmental policy
makers and research managers of the future.
These topics are discussed in more detail on page
61. Current and projected resources for investigator-
initiated grants and research centers, as well as
those for each of the core research activities
described in this Executive Summary, follow.
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500 n
400-
300-
200-
100-
PROPOSED CORE RESEARCH PROGRAM
RESEARCH GRANTS
RISK REDUCTION
ECOLOGICAL RISK
HUMAN HEALTH
RISK
Current
YeaM
Year 2
Year3
Year 4
Years
Implementation Priorities
The Environmental Monitoring and Assessment
Program (EMAP) and the pollution prevention
component of risk reduction have the highest
priority for implementation. By the second year of
the core research program, EMAP will be fully
funded, so that research on characterization can be
completed and the full monitoring network
established as soon as possible. By its very nature, a
National Monitoring Network such as we propose
here depends on comprehensive planning and
funding to succeed. Pollution prevention research
will also be fully funded by the third year.
The next priority will be to increase the
emphasis on human exposure in year three by
establishing a program on human exposure
monitoring and assessment. This program will grow
steadily in the ensuing two years.
The investigator-initiated grants program also
has a high priority for implementation. This
program will begin the first year and grow steadily
until year five, when it will attain full growth.
Additional areas of core research growth are
proposed over the next five years. These include
pollution control, ecological effects, and the
identification of future environmental issues.
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ECOLOGICAL RISK ASSESSMENT
INTRODUCTION
EPA is responsible for protecting the
environment from the adverse effects of pollutants
and damaging activities such as the disposal of
dredge material, which destroys wetlands and
species habitats. Ecological risk assessment is the
term that describes the scientific component of the
process the Agency uses to formulate policy and
regulations for controlling pollutant releases or
activities in order to prevent unreasonable damage
to ecological resources.
In general, EPA needs to conduct an ecological
risk assessment to make three types of decisions.
The first is a prospective one involving requests for
approval of releases of chemicals to the environment
or for effluent or emission limitations for categories
of sources. The second involves remedial action to
deal with problems that have been discovered, e.g.,
DDT in the food chain, mercury in river and lake
sediments, acidification of surface waters, and PCB
and dioxin contamination. The third is that of
integrated environmental management. In order to
plan and strategically manage its programs, the
Agency needs to know how effective the aggregate of
its past actions has been in protecting ecological
resources. The Agency also needs to be able to
anticipate and set priorities among probable future
threats to ecological resources in order to conduct
research and mount programs to deal with them.
The ecological risk assessment approach that
has been developed and used by the Agency has
relied almost exclusively on a combination of: 1)
single-species ecotoxicity tests best suited for single
chemical or single stressor issues; and 2) media-
specific exposure models that exclude or treat
simplistically biological mediation, transformation,
and transport. The existing approach has allowed
the Agency to make reasonable decisions about
individual chemicals, particular types of releases,
and remedial actions. However, as we face the
emerging problems of the future, the shortcomings
of this approach are becoming all too evident.
The two most important shortcomings
associated with the current approach are its
inability to predict or evaluate, after the fact, the
ecological effects of cumulative pollutant loadings;
and its inability to deal with the stresses that affect
system level structure and function.
Currently, the EPA research program on
ecological effects has been tailored to deal with the
single pollutant or single discharge type of decision.
There has been no near-term or long-term core
research program focused on the system-level
decisions that the Agency now faces in trying to
assess its aggregate effectiveness in ecological
protection and trying to deal with system-level
stresses like global change, wetland destruction,
eutrophication, and acidification. The purpose of the
proposed program is to develop the information and
methodologies that will allow the Agency to conduct
ecological risk assessments that address these
broader issues.
The core program consists of research in four
areas. The first is research needed to characterize
and classify ecological resource systems so that
specific research priorities can be established and
representative systems can be selected for
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monitoring and research. The second is design and
operation of an environmental monitoring and
assessment program that will determine status and
trends in the exposure and condition of ecological
systems and periodically assess environmental
quality. The third is research to improve the
Agency's ability to predict ecological exposure by
developing models and measurement techniques
that incorporate the chemical and biological
processes that determine actual exposure to
sensitive receptors. The final component consists of
the development of models of response that
integrate effects at different levels of biological
organization, e.g., biochemical, cellular,
physiological, population, etc. in order to predict and
assess the status and condition of ecological resource
systems.
RESEARCH ISSUES
Together, the components of the core research
program are designed to provide answers to four
critical policy-related questions that will become
most important as the Agency evolves toward a
systems view of ecological resource and protection.
What are the Ecological Resource
Systems at Risk?
This program will identify representative
ecological resource systems for purposes of designing
and setting priorities for both monitoring and
research. It will also select and evaluate appropriate
measures for monitoring the exposure and health of
these systems; develop and apply biological and
chemical sampling and measurement techniques;
survey and classify ecological resource systems;
select representative systems; and develop the
scientific basis for selection of end-points that are
appropriate structural and functional measures of
the condition of the relevant ecological resource
systems.
What is the Condition of the
Environment and How it is Changing?
The Environmental Monitoring and Assessment
Program (EMAP) is an integrated chemical and
biological monitoring program for representative
ecological resource systems. The data will be
analyzed and interpreted periodically to determine
changes in chemical exposure trends and in the
structure and function of representative ecological
resource systems. The sampling frame of the
program will allow the results to be extrapolated to
ecological resources generally.
EMAP should guarantee that large scale
ecological disasters do not result from uncertainties
in our ecological risk assessment decisions. The
onset of major indirect and cumulative effects as
well as unforeseen systemic changes should be
detected and diagnosed in time to adopt appropriate
remedies. The program should also supply a rich
data base which can be used to evaluate the
performance of regional ecological risk assessment
models and the effectiveness of policies and
regulations designed to reduce ecological exposure
and to promote ecological protection or recovery.
To What Level of Pollutants are
Ecological Resource Systems Exposed?
The primary focus of the research will be the
development of predictive models and indicators of
exposure. A critical component of ecological risk
assessment is the actual exposure of sensitive
resources resulting from the release of pollutants
into the environment. The physical, chemical and
biological reactions of a pollutant determine its
environmental pathways to sensitive receptors. The
systems view of ecological risk requires major
advances in our knowledge of these critical
mediating environmental processes and the
development of predictive models and indicators
that capture these advances, particularly for
terrestrial and marine environments.
What are the Effects of Pollutant
Exposures on Ecological Resource
Systems?
Finally, the core includes a major expansion of
ecological effects research. The purpose of this
expansion, along with the proposed new research in
characterization, status, trends, and exposure is to
respond to a fundamental shortcoming in our ability
to determine or predict the system-wide ecological
effects of major environment stresses. The goal of the
effects program is to combine theory with laboratory
and field experimentation to improve methods for
predicting the effects of single and multiple
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environmental stresses on higher levels of ecological
organization.
CORE RESEARCH PROGRAM
research and monitoring findings of representative
sites to the resource population, and quantifying the
extent and location of resources at risk.
Ecosystem Classification
A more detailed description of the proposed
program follows.
Ecological Classification and
Environmental Characterization
Year/$ M
Year/$M
Current
1
2.0
8.0 30.0 30.0 40.0 47.0
As it is unreasonable to study all ecosystems or
every biological and chemical component of all
ecosystems, it is essential that the systems chosen
for study are representative of the population or
areal extent of the resource of interest and that
studies within representative ecosystems are
focused on chemical and biological properties
indicative of their condition. Therefore, the
objectives of the ecological classification and
environmental characterization core research area
are to:
1. Classify major freshwater, estuarine, and
terrestrial ecosystems based on similar physico-
chemical, biological and/or response attributes.
2. Define quantitatively the areal extent and
population of these major ecosystems.
3. Identify indicators of system condition and
ecological endpoints of primary concern for
monitoring and effects research.
4. Refine classifications of major ecosystems based
on improved understanding of their physico-
chemical, biological, and/or response attributes.
From these studies, a necessary foundation will
be established for developing sampling frameworks
for ecosystem status and trends monitoring,
selecting ecosystems most sensitive to change from
cumulative effects of pollution, extrapolating
Current
1
5.0 10.0 10.0 15.0 15.0
Although many classification schemes have
been proposed over the years for both aquatic and
terrestrial ecosystems, few studies have been
conducted to assess the effectiveness of these
schemes in reducing sampling variance in
monitoring programs or their applicability to
reducing uncertainty in large-scale extrapolations of
exposure and effects model predictions. This
program will refine ecosystem characterization
biologically and chemically; develop new
hierarchical classification schemes for estuarine,
lake, stream and forest systems; and test existing
schemes for their applicability to the design of
monitoring systems for determining ecosystem
condition and pollutant exposure, and to the
selection of representative systems for effects studies
and model prediction extrapolation. This
classification effort will be the critical element
needed to improve monitoring systems design and
reduce uncertainty in large-scale risk assessments.
Over time and with findings from ecosystem
response studies, hierarchical, multi-scale
classification schemes can be established that will
serve as the basis for quantifying existing and
potential risk to ecological resources.
Ecological Condition Indicators
Year/$ M
Current
0
1
0
2
5.0
3
5.0
4
10.0
5
22.0
Ecological condition indicators are charac-
teristics that define the health of an ecosystem.
These may range from hunting success, tissue
burdens or biomarkers, to complex indices of species
abundance or diversity or measures of nutrient
21
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cycling rates. The definition of indicators of
condition is essential for developing cost-effective
ecosystem condition monitoring networks and for
focusing effects research. The Agency will compile
currently used indicators, test the sensitivity and
selectivity of these indicators, and identify new
indicators. These indicators, in combination with
exposure and effects data, will aid in identifying
potential ecosystem problems, in determining the
effectiveness of current control programs at the
ecosystem level, and in developing the periodic
reports on the condition of the environment proposed
in the Ecological Monitoring and Assessment
Program.
Chemical Characterization
Environmental Monitoring and
Assessment
Year/$ M
Current
2.0
3.0 15.0 15.0 15.0 10.0
With the rapidly escalating number of chemicals
entering the environment, it is essential that we
know what pollutants are present in ecosystems and
where they reside. The chemical characterization
effort will focus primarily on the development of
methods for rapid screening of multiple pollutants in
soil, water, air, and biota and on increasing the
sensitivity and selectivity of these methods. Broad-
spectrum, chemical techniques have been used
effectively to "fingerprint" surface water chemistry
and are now being investigated as tools to
characterize pathogens and bioengineered
organisms in water.
Extensions of these capabilities will lead to
improved characterization of both selected
ecosystems and the ambient environment.
Incorporation of broad spectrum analyses into a
status and trends monitoring program should
produce a cost-effective means of better under-
standing the complexity of pollutant exposures in
ecosystems.
Year/SM
Current
5.0
15.0 78.0 83.0 85.0 90.0
Current approaches to monitoring ecosystem
degradation are typically compliance oriented, site
specific, and undertaken without knowledge of the
representativeness of the results. Consequently, we
are currently unable to assess with confidence
changes in the environment such that we can judge
whether ecological resources are being protected
from pollutant damage.
The goal of the Environmental Monitoring and
Assessment Program (EMAP) is to establish a
national scale, integrated, pollutant exposure and
ecological condition monitoring network. The unit of
most interest will be the ecosystem; for example,
forests, lakes, streams, estuaries, and fresh water
wetlands; and the program will be developed around
the mosaic of these systems over the landscape. The
objectives of the network include:
Establishing baseline conditions for detecting
changes in pollutant concentrations/exposures
and ecosystem condition at regional scales.
Quantifying trends in pollutants and ecosystem
condition.
Developing causal hypotheses and identifying
emerging problems from relationships between
pollutant changes and concomitant ecosystem
changes.
Verifying predictive ecosystem exposure and
effects models.
Reporting regularly on the condition of the
environment.
EIv'AP will achieve its objectives by developing
rigorous statistical sampling designs and protocols,
by building on existing networks, by facilitating
interagency cooperation, and by maximizing the use
of existing data for developing a sound program.
22
-------
Coupled with the research in the ecological
classification and environmental characterization
program, initial efforts will be devoted to designing
the conceptual framework for the Program and then
to pilot studies and associated research. The phased
implementation of fully operational networks on an
ecosystem-by-ecosystem basis will begin thereafter.
Methods Development
Year/$ M
Current
1
1.0
1.0 10.0 10.0 10.0 7.0
The primary research elements within EMAP
are:
1. Monitoring Systems Design
2. Methods Development
3. Operational Monitoring
4. Data Base Management
5. Integrated Assessment/
Environmental Statistics
Monitoring Systems Design
Year/$ M
Current
4.0 15.0 15.0 10.0 10.0
Critical to the core program is the analysis of
data from existing monitoring programs and special
purpose surveys to develop innovative designs that
can be used to quantify ecosystem status and trends,
with known confidence, while maximizing the use of
existing monitoring systems. A high priority will be
the development of model-based systems that can be
used to extrapolate trends from existing monitoring
sites to a specific regional population of interest.
Cost-effective regional surveys that index more
complicated patterns of status also need to be
developed and pilot tested. Integrated sampling
frames that allow patterns and trends to be
compared across ecosystems and media also are
prerequisites to implementing a national
monitoring network and these will be investigated
in this research element.
A field monitoring program requires that
research techniques used for ecological condition
indicator definition and chemical characterization
be adapted to continuous and remote sampling
methodologies, often with minimally trained
operators. Reducing costs and increasing both
reliability and information gathered are essential to
this core element. Research activities include
examination of specimen banking techniques,
advanced field monitoring methods (e.g., x-ray
fluorescence spectrometry, dosimeters for animals
and plants, and fiber optics), broad-spectrum
pollutant monitoring instrumentation for field use,
and interpretation of remote imagery and
reconnaissance-level remote sensing (e.g., UV
DIAL).
Operational Monitoring
Year/$ M
Current
1
4.0
4.0 43.0 48.0 50.0 55.0
The core program includes development and
implementation of an operational network for
determining the status of and trends in the condition
of freshwater, estuarine, and terrestrial ecosystems
and associated air, soil, and water media as well as
the status of and trends in pollutant exposures/
concentrations at the ecosystem level.
23
-------
Data Base Management
Integrated Assessments/Environmental
Statistics
Year/$ M
Current
1
2.0 5.0 5.0 7.0 8.0
Year/$ M
Current
4.0 5.0 5.0 8.0 10.0
Combinations of existing data bases and
network monitoring data will be required. The
measurements and their respective uncertainties
provide the basic units for estimation and
hypothesis testing. The use of different
measurement methods and instruments along with
different calibration procedures, sampling
techniques, and the presence or absence of quality
control practices must be considered in determining
the overall uncertainty. When building data sets
from different sources, it becomes necessary to have
a mechanism for tracing the data to their origins
and for integrating the quality control information
within the data base into a comprehensive quality
assessment product. It will require several years to
develop and evaluate sound and workable
approaches for defining the uncertainties in
integrated data bases.
One of the first targets of the data base
management (DBM) core research task will be to
produce an updated directory of environmental and
resource data bases and monitoring networks. This
directory and the associated data bases will be
critical to the design of the operational status and
trends network. The second task will be the
development of a DBM system to support the
network. The key to a successful program will be
moving quality-assured data into, through, and out
of the system rapidly, in a form and format
convenient to data users. The core program will
focus not only on managing data, but also on
developing and applying innovative techniques to
increase responsiveness and reuucc costs.
Automation will be used to the maximum in the
production of annual statistical reports. Geographic
information systems (GIS) technology will dominate
the DBM system.
Operation of EMAP will fill one of the major
gaps in current ecological risk assessments. The
results will provide system-level measures of status
and trends in the condition of representative
ecological resource systems that are at risk from
environmental stresses. The data will indicate
whether any serious changes are occurring in the
condition of the ecological systems and whether
multiple pollutant or single pollutant stresses
appear to be causing the changes.
Central to EMAP will be annual reporting of
findings that are relevant to the Agency's hazard
identification and risk characterization effort. The
focus of the reports will be on indices of condition
and exposure. On a two-to-three year interval,
integrated assessments will be produced that
interpret relationships between exposure and
condition and that assess environmental quality in
general. In addition, these reports will contribute to
the verification of exposure and ecosystem effects
models as well as assessments of the effectiveness of
current control programs in protecting ecological
resources.
Considerable effort will be devoted to exploring
the data for developing hypotheses and identifying
emerging problems, statistical techniques for data
interpretation on both temporal and spatial scales,
empirical models, and for maintaining cost
effectiveness of the information gathered through
assessment of its value.
24
-------
Ecological Exposure*
Year/$M
Current
5.0
7.0 16.8 17.0 20.0 28.0
The EMAP program will provide a number of
measurements of direct or indirect exposure to
ecological resources. In some instances, the direct
measurement approach of EMAP will suffer because
of the absence of acceptable measurement
techniques. That problem is being addressed by the
methods development portion of the EMAP program.
In most cases, however, the direct measurement
approach to exposure will alone prove inadequate for
ecological risk assessment for two reasons. First,
the decision maker usually needs to know where the
exposures come from if alternatives to reduce
exposures are to be considered or if possible future
changes in exposure are to be understood. Thus,
some level of source characterization is necessary to
relate ambient levels to their sources or sites of
release. Source characterization is predominately
an engineering function which would include
research to understand the scientific and
engineering principles and mechanisms that
characterize the pollutants (type, amounts and rate
of release) from sources. However, there are
circumstances (e.g., releases from hazardous waste
sites; release of chemicals from contaminated
sediments) that do not lend themselves to an
engineering approach to characterization. To this
extent, the ecological exposure program will include
fundamental research to identify and characterize
pollutant sources that are unique for ecological
systems. Predictive exposure models that quantify
the physical and chemical behavior of pollutants are
needed to solve these problems of source attribution
and prediction.
The second reason that reliance on direct
measurements can be inadequate is that they are
often too few and too infrequent to provide estimates
of exposure to biological systems that are accurate
from the point of view of indirect and cumulative
exposures. Biomarker techniques offer the
possibility that measurements can be developed
* See also Appendix A Exposure Assessment - A Cross-
Cutting Issue
that, in combination with models, will provide much
improved estimates of indirect and cumulative
exposures to ecological resources.
The current research program has not been able
to address adequately the need to improve predictive
exposure modeling or exposure biomarkers. The
development of exposure models has focused
primarily on the need to be able to predict pollutant
concentrations in ambient water, air, and soils.
These models have been tailored primarily to predict
exposures to people. The models have not
incorporated the kind of biological processes and
pathway knowledge that is necessary to predict
exposures to sensitive receptors in ecological
resource systems.
Though now promising, research in the past to
develop biomarkers of exposure has been virtually
nonexistent. Only recently has the state of chemical
and biological science advanced to make research in
this area practicable. And only recently has there
been a recognition that advances in this area could
be most valuable toward advancing the science of
ecological risk assessment.
The expanded core program includes the five
types of research that will be necessary to improve
our ability to predict future and to reconstruct past
direct, indirect, and cumulative ecological
exposures. These five interrelated research areas
are: (1) source characterization; (2) transformation
and transport process research; (3) mathematical
model development; (4) biomarker development for
ecological exposure; and (5) field evaluation of
process descriptions, of models, and of biomarker
measures. The major research emphasis in the
expanded core program in these areas is as follows:
Source Characterization
Current
2.0
1
2.0
2
4.8
Year/$
3
5.0
M
4
5.0
5
6.0
Point or area sources discharge many known
and unknown pollutants into the air, water and soil.
Information on the chemical and physical nature of
these discharges serves to identify sources of
25
-------
pollutants in ambient media on the basis of their
elemental "fingerprints."
Mobile and stationary source characterization
are most familiar. In mobile sources, new engine
designs and alternative fuels may change the mix of
organics, NOx, and other pollutants. Changes in
catalytic converters may result in altered emissions
of toxic metals. Stationary source emissions change
with fuel mixtures, pollution control devices, raw
materials, process streams, and burner and reactor
configurations. The research here involves primar-
ily continued application of existing technology to
new sources and development of new techniques to
expand the suite of measurable pollutants.
Source apportionment techniques have been
developed which can identify far-field sources of
polluted air masses on the basis of trace element
proportions derived from the sources of fuel they
burn. Research must be extended to increase the
statistical precision with which signals can be
measured, and to evaluate the technique for non-air
pollutant sources. There are a large number of
sources that need to be characterized which do not
lend themselves to the traditional monitoring and
engineering approaches of measuring and tracing
back. This is especially true of non-point sources in
which the source strength is not easily measured or
characterized, e.g., pesticides in groundwater,
agricultural run-off and urban storm water run-off.
Transformation and Transport Processes
Year/$ M
Current
2.0
3.0 5.0 5.0 5.0 6.0
The expanded core program will examine basic
fate processes to determine exposures to sensitive
receptors for the relevant ecological resource
systems. For example, biodegradation is influenced
by the salt content of water and the tidal cycle; thus,
how near coastal systems biodegrade pollutants will
be a part of this core area. Understanding
partitioning in aquatic (fresh and saline) sediments
will be another element of the core program.
Understanding the chemical processes at
environmental interfaces and in specific
compartments is necessary to predict ecological
exposures because the receptors live at these
interfaces. The program will also include study of
the fate of pollutant complexes, since systems are
never exposed to just one pollutant at a time. The
processes that determine exposure to near coastal
resource systems from non-point source pollution,
including deposition and air chemistry, to wildlife
populations from chemical and biological pesticides,
and to freshwater aquatic systems from non-point
sources of metals and organics from atmospheric
emissions and surface water runoff will be
emphasized.
Ecological Exposure Models
Year/S M
Current
1.0
1 2
1.0 2.0
3
2.0
4 5
2.0 4.0
If the ecological effects of xenobiotics are to be
realistically assessed from observed or predicted
environmental concentrations, appropriate
ecological exposure models that characterize and
predict the bioaccumulation/bioconcentration and
bioavailability of chemicals must also be developed
and validated.
The first expansion will focus on estuarine
eutrophication models and on upgrading general
water quality models to better simulate limiting
nutrients, red/green tide blooms and interactions
with toxics. Research will also focus on the
definition of various terrestrial ecosystem types
(e.g., croplands, grasslands, forests, rangelands) in
order to develop food chain models, species
completion models, predator-prey/behavior patterns
and uptake/distribution models needed to
complement existing terrestrial exposure models.
The second expansion will include
uptake/bioaccumulation, predator-prey, food chain,
and behavior-avoidance, in the improvement of
aquatic exposure assessment models.
Currently, models are being developed for
several media, including surface and subsurface
water, terrestrial ecosystems, and large lakes.
26
-------
Ecological Exposure Biomarkers
Ecological Effects
Current
0
1
1.0
Year/$ M
234
5.0 5.0 5.0
5
7.0
Year/$ M
Current
2
19.0
19.0 38.0 40.0 43.0 60.0
Very little research is being conducted in this
area now. However, it is possible to relate exposure
to a specific pollutant or stress by analyzing
subcellular and cellular responses within certain
ecological receptors (organisms). Some of the early
work with stress proteins and metal contamination
in fish indicates that this area has merit as core
research. This form of ecological epidemiology can
be used to determine exposure retrospectively and to
validate the work in pathways and ecological
modeling. The first three years will be devoted to
testing hypotheses using key species occupying
critical compartments of the ecosystem. The
selection of species and compartments will be
influenced by the work on ecological indicators and
the early results of the status and trends program.
Field Evaluation
Year/$ M
Current
0
3.0 5.0
If a predictive exposure model is to be used
effectively, it must be evaluated. This core area will
validate the ecological exposure models and
exposure biomarkers developed for the various
ecosystems being studied. The first model that will
be validated is the prototype row-crop model that
has been developed to predict avian exposures from
chemical pesticide applications. As other models and
biomarkers are developed they will be evaluated in
the field.
The central theme of the integrated ecological
risk assessment research program is to provide EPA
with the combination of data, knowledge and
methods to enable assessment of the risks of
pollutant exposure to ecological resources. The
fundamental assumption in the design of this core
research program is that ecological risk assessment
must consider the potential long-term, indirect and
cumulative system-wide impacts associated with
Agency policy and regulatory options.
In the past, assessment of ecosystem response
has been based on three approaches, each of which
has suffered from serious deficiencies: 1) ex-
trapolation from small-scale experimental results
such as bioassays or microcosms that do not capture
the full range of ecosystem interactions and have
been known to misrepresent ecosystem sensitivity,
2) results from specific field studies or impact
assessments which have rarely been sufficient to
extrapolate to other systems, and 3) attempts to
construct ecosystem dynamic models which have
suffered from the lack of observations needed to
understand and quantify basic system processes.
The cost-effective prediction of potential system-
wide ecological effects from pollutants and other
stresses will require advancement in our state of
knowledge about responses at several levels of
biological organization from biochemical up to
system level indicators. The core program is
designed to investigate structural and functional
relations at these different levels with early priority
being accorded to new coastal systems, to population
and community studies, and to field evaluation of all
predictive effects models.
The core program assumes that there is a
spectrum of needs to predict effects at different
levels of biological organization. At one end of the
spectrum is the need for first-order prediction of
effects. In some instances, an appropriate screening
level ecological risk assessment can be carried out
27
-------
simply based on knowledge of the molecular
structure of a chemical or the results of a single
species bioassay. At the other end of the spectrum,
there are cases where a complete ecosystem-effects
model prediction would be desirable. The research
program tries to satisfy this need for a range in
predictive ability.
The components of the program, along with the
principal approaches and priorities, are as follows:
Ecosystem Effects
communities and ecosystems, these are not likely to
be sufficient for EPA's ecological assessment needs.
Therefore, there is a need to determine the validity
of the assumptions upon which the use of data from
lower levels of biological organization to predict
higher level effects is based.
The emphasis during the first three years of the
program will be on validation of existing bioassay
tests and models. Plans will also be developed under
the effects research program. Evaluation of the
complex models will begin in year four.
Year/$ M
Current
1
3.0
3.0 16.0 17.0 20.0 27.0
Ecosystems are so complex and variable that we
are unlikely to understand and describe them
completely in the near future. The most feasible
approach is to define measurable indicators of
ecosystem condition and response to stress,
determine the range of natural variation of these
indicators, and measure and model the response of
these indicators to anthropogenic stress at the
ecosystem level.
During the first two years, priority will be given
to field data collection and modeling for near coastal
ecosystems and freshwater wetlands and to
indicator development and retrospective studies for
all major ecosystem classes. Additional major
ecosystems will be added for field data collection and
modeling in the third through the fifth years in the
following order: forested ecosystems, fresh surface
waters, and agroecosystems. EPA currently has
little or no research at this complex level, except in
acid deposition.
Field Validation
Year/$ M
Current
1
3.0
3.0 3.0 3.0 3.0 3.0
Although major advances can be expected in
direct measurement of the effects of stress on higher
levels of ecological organization such as
Quantitative Structure-Activity
Relationships (QSAR)
Year/$ M
Current
1
1.0
1.0 3.0 3.0 3.0 5.0
The potential environmental effects of limited
numbers of hazardous chemicals can be tested and
evaluated. The QSAR approach develops carefully
selected reference data and relates the activity of
each chemical to the structure using computational
chemistry techniques. QSAR provides estimates of
bioaccumulation potential, acute and chronic
toxicity, and many chemical properties important in
forecasting fate and effects.
The development of predictive QSAR technology
follows a logical progression of increasing
sophistication in computational methods and
reference endpoints. EPA needs four primary
reference data sets: acute toxicity,
metabolism/biodegradation, bioaccumulation, and
macromolecule reactivity (DNA adducts). Two
databases are nearing completion. The reference
data set for metabolism/biodegradation will be one of
the first areas for core research. Another major
expansion of QSAR will be the development of a
systematic reactivity profile of chemicals toward
DNA and other proteins. This reference set and the
associated reactivity models will require five years
to complete.
Current activities involve developing
quantitative structure-activity computational
methods for anticipating the environmental
behavior of chemicals from chemical structure. Key
28
-------
structural properties which make chemicals
hazardous are being identified to provide the basis
for initial risk assessments before test data are
available. The products of structure-activity
research permit EPA to focus resources on the
greatest chemical hazards and identify potential
risks before environmental damage occurs.
Comparative Toxicology
Year/$ M
Current
1.0
1
1.0
2
1.0
3
1.0
4
1.0
5
3.0
Single Species Effects
Year/$ M
Current
2.0
1
2.0
2
2.0
3
3.0
4
3.0
5
4.0
Acute and chronic laboratory toxicity tests that
measure effects of pollutants on animals and plants
have provided the primary basis for ecological risk
decisions made by EPA. Single species-single
pollutant tests will continue to be important in
making decisions about restricting chemical use, in
setting ambient environmental criteria and in
establishing permit limitations. This continued use
is based largely on advantages of short time
requirements, low resource intensity and a large
scientific knowledge base that has accumulated
during the last 20 years.
To ensure reliable extrapolation of single species
laboratory data to ecosystem effects for chemicals
and chemical mixtures, the feedback components
between effects endpoints in the laboratory and
those in mesocosm or field studies need to be
coherent. The core program will be expanded to
prepare the scientific basis for species extrapolation
models, and to test, in the laboratory, hypotheses
that biomarkers at cellular levels can be used for
extrapolating among species and to higher levels of
organization. In year three, the program will be
expanded to develop species extrapolation models
and to begin controlled experiments to determine
the utility of biomarkers under field conditions.
Results obtained here are critical to understanding
effects and to extrapolating across species, route to
route, and low dose to high dose. Current activities
are oriented toward supporting water quality
criteria, and providing the basic data for
structure/activity research correlations.
How precisely can we predict the response of one
species, population or community to a given stress
based on lexicological data from another species,
population, community, or stress?
To achieve a more ecologically based approach to
risk assessment, comparative toxicology must define
species at risk and stressors of concern under
representative marine, freshwater, and terrestrial
ecosystems. Existing comparative toxicological data
on individual species only allow rough estimates of
acceptable levels of environmental stress. We use
these data to predict environmental impacts
through construction of models and empirical dose-
response relationships. Currently, our approaches to
hazard assessment range from simple and informal
attempts to more elegant arrays of relationships and
mathematical expressions construed to represent an
ecosystem. These complex approaches to cause and
effect assessments are neither reliable nor
sophisticated enough to provide comprehensive,
quantitative inputs for ecological risk assessment.
Few approaches have been validated (field verified)
or had their uncertainties quantified.
In the first three years, data and related
information will be collected and critically reviewed.
Existing databases will be statistically analyzed to
define species at risk, stressors of concern, and
mechanisms and relationships that need to be
studied.
Research will be conducted to develop a database
on dose and significance of residues in biota for
short- and long-term effects, improve techniques for
determining exposure/dose, determine environ-
mental factors affecting exposure/dose-response
relationships, identify species required for ecological
representation to determine species at risk, evaluate
current and new effects endpoints, and define
29
-------
ecologically significant endpoints (structure and
function) for community level risk assessments.
Beginning in year four, we will develop
empirical models for species/life state at risk and
stressors of concern, cause-effect relationships
(species to community level), schemata for
diagnosing cause-effects, and endpoints necessary
for evaluating status.
Finally, toxicokinetic models will be developed
to compare exposure, dose, and effect from one
organism or situation to another, and mechanistic
lexicological models will be developed to extrapolate
among biological organization and classes of
stressors.
The current efforts in comparative toxicology
focus on predicting effects in other species and at
different organizational levels. These studies are
fundamental to define the relationships among
various endpoints at population or community
levels.
Population Effects and Models
Year/$ M
Current
1
2.0
2.0 4.0 4.0 4.0 6.0
Even when single-species methods suggest that
impacts of environmental stressors should be
minimal, natural populations can be devastated by
indirect impacts unobservable in a laboratory
setting. Indeed, many of the ecological impacts of
Agency concern result from events at the population
level of organization and have not been directly
observed in physical laboratory models. Examples
include the long-term bioaccumulation of pollutants
(e.g., DDT and PCB) via food chains, increased
maternal susceptibility and maternal/fetal
transmission or seasonal physiological stress, and
transmission of toxic contaminants in the human
food chain.
The initial increase in resources will be devoted
to the assessment of existing population models for
aquatic and terrestrial species and the expansion of
these models based upon results provided by the
ecological effects research program.
The increased resources in years two and beyond
will be devoted to the development of new field data
for both aquatic and terrestrial species/populations
so as-to quantify natural variation, identify the key
demographic parameters and their response to
pollutant stress, and to evaluate and improve the
models discovered/ postulated in the initial phases of
this core expansion.
Current activities are limited to developing and
testing empirical models that: a) predict the effects
of stress on physiological fitness as it relates to
demographic parameters, b) estimate the variability
of populations in space and time, and c) relate
genotypic variability to demographic response to
stress. Current activities address mainly acid
deposition effects.
Community Effects
Year/$ M
Current
7.0
1
7.0
2
9.0
3
9.0
4
9.0
5
12.0
How do major terrestrial, freshwater, and
marine communities respond to stressors of
regional/national importance? How precisely can we
predict the responses of select communities using
exposure-response data from a single species or
another community exposed to a similar or different
stress?
The status or response of a community cannot be
predicted by a simple addition of the status or
response of its individual components. The Agency
now regulates environmental pollutants largely on
the basis of a single species/single pollutant risk
assessment paradigm which ignores complex
physical, chemical, and biological interactions that
may magnify, mitigate, or have no effect on an
adverse response. Community response studies are
essential if our eventual environmental goal is to
protect complex ecosystems through credible
ecological risk assessments.
30
-------
In the first three years, the program will
critically examine existing data to define: a) most
reasonable structural and functional community
endpoints, b) important communities most likely to
be affected (exposed and sensitive) by major classes
of stressors. Controlled community (microcosm and
mesocosm) studies will be conducted to: a) confirm
the value of endpoints for major communities and
stressors, b) define interactions among community
responses, variable stressor scenarios (single and
multiple stressors), and environmental parameters,
c) provide a basis for relating community structure
and function to experimental toxicity data.
Beginning in the fourth year and continuing,
community level stress-response models will be
developed to predict community structure/process
responses given stress statistics, community
description, and environmental variables, and
identify causal links between effects at or below the
whole-organism level and those at or above the
population level.
Community level assessment integrates a
multitude of lower level concerns and impacts. It
offers a different perspective to the interactions of
the resources and addresses endpoints which
sometimes are meaningless at other levels. The key
is to develop the tools to perform risk assessments at
this level and above and to assess the impact after
the insult. Current activities are limited mainly to
acid deposition.
IMPLEMENTATION STRATEGY
The long-term core strategy is designed to
provide the data, knowledge, and methodologies
necessary if the Agency is to progress from
toxicology to ecology as the basis for making
decisions to protect the environment. At least three
major developments in the area of environmental
protection dictate the move to decision-making
based on ecological risk assessment. The first is the
realization that the aggregate effect of apparently
rational decisions about single chemicals, releases,
or stresses may place a total multi-pollutant stress
on ecological systems that is damaging. The
Germans use the term neuartige schaden to describe
this new form of multi-pollutant stress and its
effects on forests. The second development that is
driving the Agency toward a systems view is the
realization that indirect and cumulative effects from
pollutants are a serious threat to ecological
resources and can only be anticipated by having the
requisite understanding of pollutant/systems
interactions. Finally, some of the most important
stresses that have to be dealt with now are so
pervasive that their full impact can only be
understood at the systems level, e.g., regional
acidification, eutrophication of coastal waters,
elimination of wetlands, and global climate change.
Progress in ecological risk assessment for
pollution stresses will require a substantial research
effort over the next ten years, in a broad range of
monitoring, research and modeling activities for the
different ecological systems. This strategy proposes
to begin building the research program over a five-
year period.
The strategy presents a deliberate view of how
the research program should be phased in order to be
most effective. The strategy assumes that the initial
phase of the program will consist of an intensive
effort to define the types of ecological systems at risk
and to develop measures that can serve as indicators
of the condition of those systems with respect to
exposures to stresses and state of health. The
program will complete a comprehensive review of
available information on classifications, inventories
and current status of ecological resource systems
and their exposure to pollutants. Studies and
workshops will be commissioned to identify,
evaluate, and develop measures that might serve as
indicators of condition or stress to these systems in
monitoring and research studies. Designs will be
developed utilizing existing data systems for
initiating the status and trends monitoring
program.
The monitoring systems will provide baseline
information that will permit the Agency to evaluate
the effectiveness of its prior actions. Working
cooperatively with the National Oceanic and
Atmospheric Administration, the first full-scale
monitoring effort will be implemented for near
coastal and marine systems. To achieve our goal of a
holistic view of the nation's ecological resources, we
will work cooperatively within the Federal
establishment to phase in monitoring programs for
31
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the other ecological resource systems as scientific
feasibility and economic considerations dictate.
The early characterization and classification
efforts will also provide the basis for later expansion
of the exposure and ecological effects portions of the
core program. The emphasis of the research will be
on the prediction of effects on systems. The program
will strive for integration of studies at biochemical,
physiological, organismic and systems levels to
provide the knowledge of system/pollutant inter-
actions necessary to predict ecological exposures and
risks.
The program will establish intensive
experimental and control field sites for each of the
ecological resource systems at risk. These sites will
include comprehensive baseline monitoring as well
as extensive controlled experiments to test cause
and effect relations and to evaluate exposure and
effects models. The first priority in the exposure and
effects area will be on near coastal and estuarine
systems. Implementation of the wetlands and
surface water system programs will follow.
The following chart depicts the estimated budget
in Ecological Assessment for current and ensuing
years.
200-
100-
ECOLOGICAL RISK ASSESSMENT
ECOLOGICAL
EFFECTS
EXPOSURE
ASSESSMENT
ENVIRONMENTAL
MONITORING
AND ASSESSMENT
PROGRAM
CLASSIFICATION
Current
Yearl
Year 2
Year 3
Year 4
YearS
32
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HUMAN HEALTH RISK ASSESSMENT
INTRODUCTION
The Environmental Protection Agency (EPA)
increasingly relies on quantitative assessment of
health risks to make decisions about protection of
public health. The utility of the risk-based approach
for decision making is dependent upon the
availability of an adequate data base that is
appropriate for the questions being asked.
Insufficient and inappropriate data can lead to large
uncertainties that, in turn, allow wide latitude for
interpretation. Where the underlying scientific
uncertainties are great, the data may support
diametrically opposed interpretations, each with
dramatically different ramifications for related
regulatory decisions. The goal of the core research
program in human health risk assessment is to
provide sound data, improved methods and validated
models that will lead to better decisions.
The elements of the risk assessment process, as
well as the interrelationships between research, risk
assessment, and risk management are shown in
Figure 1. Research provides the scientific data bases
that underlie the three steps in risk assessment;
namely, hazard identification, dose-response
assessment, and exposure assessment. Once a
hazard has been identified, risk characterization can
be thought of as the combined results of exposure
assessment and dose-response assessment with the
weight of the evidence. Depending on the pollutant
and the situation in question, lack of understanding
about exposure or dose-response can result in
uncertainties associated with the final risk number
that span several orders of magnitude.
The major scientific issues that produce
uncertainties in the risk assessment process are: (1)
lack of appropriate and adequate data; (2)
limitations on our ability to extrapolate from
artificial experimental conditions to actual real-
world situations; and (3) lack of understanding of
the basic biological mechanisms that explain the
relationship between exposure, dose at the target
site, and effects. As we have come to realize, the
major contributors to uncertain health risk
assessments are deficiencies in our knowledge about
the underlying physical (e.g., atmospheric and
aquatic dispersion characteristics, human activity
patterns), chemical (e.g., chemical reactions and
transformations), and biological (e.g., metabolism,
disease and repair processes) mechanisms that affect
the validity of extrapolation assumptions.
The purpose of this document is to provide a
brief overview of the core research program in
human health risk assessment and to present the
rationale for growth over the next several years in
key research areas.
RESEARCH ISSUES
Traditionally, the Agency's risk assessment
efforts have focused on the carcinogenicity of long-
term, low-level exposures to single environmental
agents. It is now recognized, however, that there is a
real need to expand our focus to include noncancer
health effects, and the complex exposure conditions
that exist for both single and multiple chemicals.
This will necessitate a coherent and coordinated
research program that improves substantially our
understanding of the relationships among exposure,
33
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Research
Risk Assessment
Risk Management
Laboratory and field
observations of
adverse health
effects and exposures
to particular agents
Information on
extrapolation methods
for high to low dose
and animal to human
Field measurements,
estimated exposures,
characterization of
populations
\
Hazard identification
(Does the agent
cause the adverse
effect?)
Exposure Assessment
(What exposures are
currently experienced
or anticipated under
different conditions?)
Dose-Response
Assessment (What is
the relationship
between dose and
incidence in humans?)^
Risk Characterization
(What is the estimated
incidence of the
adverse effect in a
given population?)
Development of
regulatory options
Evaluation of public
health, economic,
social, political
consequences of
regulatory options
Agency decisions
and actions
Figure 1.Elements of Risk Assessment and Risk Management (From: National Academy of Sciences [NAS], 1983.)
dose, and associated health consequences. The EPA
research program must emphasize the direct
application of basic scientific knowledge to the
short-term and long-term problems facing the
Agency.
Development of a stronger scientific basis for
health risk assessment is a prerequisite for
improved decision-making about protection of public
health. Among the critical issues that must be
addressed in order to reduce the uncertainties in
risk assessment are the following:
Identification of Potential Environmental
Health Hazards
- We must have the capability to determine, in a
timely manner, whether there is a causal
relationship between an environmental factor
and an adverse health outcome.
- Examples of recent technologies, activities, and
issues for which hazard identification is needed
include biotechnology, ultraviolet radiation
resulting from stratospheric ozone depletion,
commercialization of superconductors,
alternative fuels for motor vehicles, and mineral
fibers used to replace asbestos.
Improved Extrapolation Methods
- Health risk assessment often relies on
extrapolation from animals to humans and from
high to low exposures.
- Because of our lack of understanding about basic
underlying biological mechanisms there are
large uncertainties associated with this
extrapolation process.
- We must undertake research that will enhance
our understanding of physiologic and
34
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biochemical mechanisms, including disease and
repair processes.
- Our aim should be to develop methods that take
account of the relationship between exposure
and dose (i.e., physiologically based
pharmacokinetic models) and between dose and
effect (i.e., biologically based dose-response
models) that reduce uncertainties in health risk
assessment.
Evaluation of Human Populations
- It is essential to obtain exposure, dose, and
effects data in human populations in order to
assess the status of the public health, to identify
potential problems, and to evaluate the efficacy
of risk reduction measures.
- Human data are required to evaluate and
validate the extent to which effects in animals
are analogous or homologous to those observed
in people.
- The acquisition and utilization of human data to
estimate exposures and to document effects is an
important component of improving health risk
assessments.
- It also is important to identify, study, and
safeguard population subgroups which may be
at elevated risk because of either increased
susceptibility or high exposures.
- The ability to use biological markers of
exposure, effects, and susceptibility in human
populations is rapidly becoming a reality.
- EPA must be prepared to take advantage of
these advances in the state-of-the-science to
improve decisions about protection of public
health.
Integrated Exposure Assessment
- People are exposed to a wide spectrum of
chemicals during their routine daily activities.
- Environmental contaminants may enter the
body through inhalation, ingestion, and/or
dermal absorption.
- Exposures may be episodic (e.g., chemical spill),
intermittent, short-term (e.g., rush hour traffic),
chronic, long-term (e.g., contaminated drinking
water), or some combination thereof.
- Better information about actual human
exposures, including magnitude, duration,
frequency, and route, will improve health risk
assessments substantially.
Health Risk Assessment for Non-cancer
Endpoints
- It is now clear that there are often a variety of
health outcomes that may arise from an
environmental insult.
- In addition to carcinogenicity, effects may
include any or all of the following-pulmonary,
cardiovascular, reproductive, developmental,
neurologic, immunologic, and hepatic.
- Noncancer health risk assessment depends on
our ability to determine which health outcomes
are important, for which environmental
contaminants, and in what kinds of situations.
- It is important to move beyond the current "safe
dose" approaches to noncancer effects (e.g.,
reference doses, maximum concentration limits)
and to develop an appropriate methodology for
quantitative risk assessment.
- This will be a challenging endeavor in which
criteria for defining the adversity and severity of
effects must be established and the possibility
that different effects can be induced in multiple
organ systems must be taken into account.
Hazard and Risk Assessment of Complex
Mixtures
- Human exposures to environmental
contaminants typically occur not to single
agents, but rather to a complex mixture or
"soup" of agents.
- Examples include emissions from hazardous and
municipal waste incinerators, urban air
pollution that is produced by a combination of
primary emissions from mobile and stationary
sources and secondary products formed in
35
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atmospheric reactions, drinking water
contaminants that include wastewater effluents
and disinfection by-products, pesticide residues
and degradation products on foods and in ground
water, and indoor air pollution in residential
and commercial buildings.
- The Agency must develop a methodology for
hazard identification and risk assessment of
complex mixtures that will be protective of
public health.
- In the meantime, developing testing strategies
to establish which components of a mixture are
most hazardous and to compare the health risks
of various mixtures is an appropriate focus for
the research program.
- In the long-term, however, it must be
determined whether it is reasonable to assume
that the health risks of a particular pollutant
mixture are equivalent to the sum of the
individual risks associated with specific mixture
components (i.e., the assumption of additivity of
risks).
All of the research issues mentioned above are
long-term questions that cut across environmental
media and regulatory offices. They are the basic
scientific questions that EPA must address if we are
to make substantial progress in assessing the
human health risks of environmental exposures.
RESEARCH APPROACHES
In order to carry out a research program that
will markedly improve health risk assessment, it is
necessary to utilize the full range of research
approaches. Thus, the strategy for addressing the
important questions in a systematic manner will
include a combination of four major approaches.
Animal Studies - the appl ication cf:,-. vitro and
in vivo research techniques to laboratory
animals in order to better understand exposure-
dose-effect relationships
Human Studies - clinical studies, epidemiologic
investigations, and in vitro techniques applied to
human tissue, aimed at understanding
exposure-dose-effect relationships in humans
Structure-Activity Relationships - research to
examine the relationship between molecular
structure and biological activity
Mathematical Models - the use of appropriate
mathematical and statistical techniques to
develop and validate predictive models
Key Questions to be Addressed
What are the important environmental
pathways by which contaminants are
transported through the air, water, and soil?
What chemical, physical, or biological
transformations do contaminants undergo as
they move through the environment?
What is the magnitude, duration, frequency, and
route of exposure for human populations under
real-world conditions?
What are the characteristics of people, places,
and pollution that may be incorporated into
mathematical exposure models and how can
such models be validated to assure that they
estimate exposure with acceptable accuracy?
How much of a contaminant to which an
individual is exposed actually enters the body,
how is it transported, metabolized, stored or
eliminated and what is the dose to the target
tissue?
What is the nature of the relationship between
exposure, dose, and health effects for important
environmental contaminants?
What are the mechanisms of disease and repair
that influence the health outcome of
environmental exposures?
Which biological processes and interactions do
we have to represent numerically in order to
develop mathematical dose-response models of
acceptable accuracy?
36
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Resource limitations obviously prevent a
comprehensive treatment of all these issues. The
goal is to identify the highest priority areas within
and between issues so that resources can be focused
on the most critical questions.
CORE RESEARCH PROGRAM
The outline of the core research program is given
in Table 1. The relationship between components of
the outline and the sequence of events leading from
pollutant emissions to human health effects is
shown schematically in Figure 2. Definitions of
important terms are as follows:
Table 1. Human Health Risk Assessment Core Research
Program
Hazard Identification
Screening and Characterization
Structure-Activity Relationship
Dose-Response Assessment
Dose Measurement/Extrapolation Methods (Effects)
Biologically Based Dose-Reponse Models
Human Exposure Assessment
Source Characterization
Predictive Methods
Direct Measurement
Dose Estimation/Extrapolation Methods (Exposure)
Hazard Identification: Research to determine if
the agent causes an adverse effect.
Screening and Characterization: the
development, refinement and validation of
methods for determining toxic effects on key
target systems.
Structure-Activity Relationships: investigations
of the quantitative relationships between
molecular structure and biological activity.
Dose-Response Assessment: Research to
determine the relationship between dose and
incidence in humans.
Dose Measurement/Extrapolation Methods
(Effects): development of data bases and models
to estimate the dose that actually reaches the
target tissue and determine the relationship
between that dose and associated health effects.
Biologically Based Dose-Response Models:
development of models that incorporate
biological formation and mechanistic hypotheses
into quantitative dose-response extrapolation.
Human Exposure Assessment: Research to
determine the exposures experienced or anticipated
in the real world by individuals or populations.
Source characterization: determination of
pollutant concentrations in vehicles that impact
individuals or populations.
Environmental Fate: collection of data and
development of models that characterize
pollutant emissions, their movement through
the environment, and their disposition and
concentration in air, water, soil or other media.
Predictive Methods: integration of data on
environmental or microenvironmental pollutant
concentrations and information about human
activities and characteristics to estimate
exposures.
Direct Measurement Methods: direct
measurements of pollutant concentrations that
individuals are exposed to using portable,
personal monitors.
Dose Estimation/Extrapolation Methods
(Exposure): this approach uses measurements of
delivered dose within the organism to estimate
exposure including the reconstruction of historic
exposures.
The following text provides a brief justification
for expansion of effort within key topical areas. The
presentation is organized according to the outline in
Table 1.
37
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Human
Exposure Assessment
Hazard ID
Dose-Response
Environmental
Pathways
Environmental
Conditions
fate&
transport
fate&
transport
Exposure/
Dose
predictive
methods
direct
methods
Figure 2. Human Health Risk Assessment Core Research Program
dose
estimate
screening
/characteri-
zation
SAR
BBDR
Hazard Identification
Year/($M)
Current
5.4
5.4 5.4 5.8 6.0 6.2
Screening and Characterization
Current
4.4
Year/($M>
12345
4.4 4.4 4.6 4.8 5.0
This area of the core research program will
develop the test methodologies and analytical
models used in the hazard identification step of the
risk assessment process. Hazard identification has
been defined as "the process of determining whether
exposure to an agent can cause an increase in the
incidence of a health condition (cancer, birth defect
etc.)" (NAS, 1983). All EPA programs require
improved and expanded hazard identification
methods for the following reasons: (1) to identify
potential health hazards requiring further
investigation (screening-problem identification), (2)
verification (validation) that the suspect effect is
indeed caused by the exposure (characterization)
and (3) identification of testing strategies -nd
methods for use in the development of testing and
risk assessment guidelines.
Test methods research develops and validates
methods for identifying and characterizing the
effects of environmental pollutants on biological
systems. This research effort is a dynamic one that
builds on new and unanticipated advances in
biomedical science to develop more diagnostic and/or
efficient methods for identifying and characterizing
the full range of toxic effects associated with
chemical exposure. The modest, but stable increase
in this area will ensure the continued development
and validation of state-of-the-science test methods.
The increase will support expansion of test methods
research in target organ toxicity and support work to
refine test methods in neurotoxicology, reproductive
toxicology, hepatotoxicity, immuno toxicology, and
pulmonary toxicology to improve their predictive
capabilities for identifying potential health hazards
from exposure to environmental agents.
38
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Structure-Activity Relationship
Current
1.0
Year/($M)
12345
1.0 1.0 1.2 1.2 1.2
A major goal of structure-activity relationship
research is the development of rational models for
molecular toxicity. These models facilitate the
prediction of the potential biological effects of
individual chemicals from their relationship to other
members of the same chemical class. The limited
increase in this area will enhance our current
program and allow for consideration of a broader
spectrum of environmental contaminants and
biological endpoints. These data are important to the
regulatory and scientific issues associated with
health risk assessment. In other activities the
methods that form the basis for these models are
being developed. This additional research will
provide a basis for understanding the underlying
mechanisms of action for the toxicity of the classes of
chemicals selected and provide a test of the utility of
these methods. Models of this type will provide an
additional rational basis for selecting agents which
require more in-depth analysis of their potential
hazard.
Dose-Response Assessment
Year/($M)
Current 12345
24.2
24.3 24.8 258 28.0 30.3
Dose-response assessment is the quantitative
characterization of the relationship between a given
exposure to an agent and the ultimate health
outcome. Two major uncertainties affect the
Agency's ability to accurately conduct dose-response
assessments: (1) limited understanding of the
relationship between ambient exposure and the dose
at the site of action; and (2) limited understanding of
the biological mechanisms responsible for the
observed effects. These issues will be addressed
through a coordinated research program to improve
methods for dose estimation and the development of
biologically based, dose-response models (BBDR).
Activities to improve the estimation of dose will
concentrate on the development and validation of
biomarkers of exposure/effect and pharmacokinetics
research. The latter focus will link with both the
Human Exposure Assessment core activities as well
as with BBDR modeling efforts.
Dose Measurement/Extrapolation Methods
(Effects)
Current
6.4
Year/($M)
1234
6.5 7.0 7.5 8.0
5
9.3
With greater emphasis being placed on
quantitative aspects of risk assessments, the ability
to estimate the toxic dose becomes critically
important. Development of data bases and models to
estimate dose is an integral component of the core
research program, for the results of these activities
will directly impact on the development of
biologically based, dose-response models (BBDR), as
well as serve to validate assumptions used in the
development of exposure models. Dose estimation
efforts in the health area will generate data and
models on direct measures of delivered dose (i.e.,
parent or metabolite) or dose surrogates (i.e.,
biomarkers). This information will be linked with
the knowledge/hypotheses regarding the
physiological processes that influence attainment
and maintenance of dose at the target and the
ultimate expression of effect.
(a) Pharmacokinetics
A major emphasis in this area will be identifying
and accounting for intra- and inter-species
differences in pharmacokinetic/pharmacodynamic
processes. Initial work will be a continuation of
efforts to develop simplified, prototypic PK models
(i.e., accounting for limited species and exposure
variables) primarily in the areas of pulmonary,
developmental toxicology, and cancer. Subsequent
growth would extend these efforts to other target
systems (e.g., neurotoxicology). Another
evolutionary component of this program would
relate to the development of PK-effects models for
complex exposures (i.e., more than a single agent
39
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and/or exposure variable). Early efforts will develop
consensus strategies for defining complex exposure
interactions including putative, mechanistic
interactions. Subsequent work will test, validate,
and recalibrate these initial complex exposure
models. The magnitude of effort in the PK area
requires relatively significant expansion of the skill
mix and resources available over the next several
years. Thus, the majority of relative growth is
anticipated in this core area.
(b) Biomarkers
Scientific advances in the next several years are
likely to provide new biomarkers that are more
sensitive and specific methods for measuring
exposures, determining susceptibility to disease,
and characterizing the health related outcomes.
When applied in parallel studies of humans and
experimental systems, they will also provide new
approaches to understanding the similarities and
differences between humans and experimental
systems widely used in risk assessment on both an
empirical and a mechanistic level. In response to
these opportunities, we will establish a broad based
program in biomarkers, focusing initially on
markers for genetic effects. The increased resources
in following years would enhance this program by
expanding the efforts to include other effects such as
immunologic, neurologic, reproductive, and other
outcomes.
Biologically Based Dose-Response Models
Year/($M)
Current
17.8
17.8 17.8 18.3 20.0 21.0
The overall goal of this core program is to evolve
models for the prediction of human health risks
under realistic exposure conditions. A major part of
this process entails moving from the current limited
approach for quantitative risk assessment (i.e., RfD
cr reference uose and uncertainty factors) to more
thorough and scientifically sound dose-response
analyses. This goal is achieved by developing models
that incorporate biological information and
mechanistic hypotheses into quantitative dose-
response extrapolation. Four basic components
comprise this research area: (1) elucidation of basic
mechanisms and processes; (2) inter- and intra-
species comparisons (including the development of
homologous models); (3) delineation of predictive
end point relationships within and across target
systems (processes); and (4) enhancement of the
human data base (i.e., an increase in
epidemiological capabilities). Initial "core years"
will reflect a continuation of current efforts in these
areas and require limited resources. It is anticipated
that these current base efforts will define and
crystallize the most profitable avenues to pursue in
developing BBDR models.
In order to describe growth in this core area, one
must examine the state of development and research
priorities for the various target systems (processes)
as related to the four component issues described
above. Thus, most of the disciplines (e.g., cancer,
neurotoxicology, etc.) will have some activity in each
of these four areas. However, the sequence of
questions to be addressed may differ markedly.
Because of historic attention, areas such as cancer,
developmental toxicology, and pulmonary toxicology
have more substantial data bases and are beginning
to integrate and test mechanistic hypotheses into
BBDR modeling. It is anticipated that funding in
these areas would remain essentially stable over the
next several years. Other areas such as reproductive
toxicology and neurotoxicology are accruing data
bases that within the next few years will provide
clarification on basic issues of species homology and
end point interrelationships to provide testable dose-
response models. A gradual increase in scientific
and biostatistical expertise will be needed to
advance these areas. Other areas are in the early
stages of formulating a comprehensive strategy for
assessing health risks (i.e., immunology and
heritable genetic risk). It is anticipated that growth
in resources and expertise will be increased
relatively more in these less advanced areas.
An integrated human health assessment
program must develop a framework for linking
progress in its core components (i.e., exposure and
effects) from its inception. Such a network will be
established early on. Moreover, long-term research
planning will reflect a growing emphasis of
resources directed at the integration of exposure,
pharmacokinetics, and BBDR modeling. Similarly,
progress will also entail moving from simplified
40
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exposure-effect paradigms to the quantification of
risks associated with complex exposures.
The ultimate product of these efforts will be
more scientifically defensible risk assessments for
both cancer and noncancer endpoints, especially in
pulmonary toxicology, neurotoxicology, immuno-
toxicology and reproduction and developmental
toxicology.
Human Exposure Assessment*
Year/($M)
Current
20.0
22.1 27.8 49.8 55.2 60.9
Exposure assessment is the qualitative or
quantitative determination/estimation of the
magnitude, frequency, duration, and route of
exposure. The practice of exposure assessment
attempts to quantify the contact (exposure) of
chemical agents and humans through air, soil, water
and food pathways, and the subsequent absorption
into the body (dose) so that this information can be
used in dose-response relationships to predict risk.
The goal of the exposure assessment program is to
provide accurate exposure information for Agency
risk managers and decision-makers to use in risk
assessment and risk management.
This core research program proposal outlines a
program that will result in an integrated approach
to exposure assessment, using three different
approaches to exposure assessment: predictive,
direct measurement, and dose
estimation/extrapolation methods. The predictive
approach characterizes the chemical environment
and human activity patterns, then estimates
exposure by linking these data. The direct
measurement approach uses personal monitoring
devices at the point of contact with humans to
monitor the intensity of contact while it occurs. The
dose estimation/extrapolation approach uses mea-
See also Appendix A, Exposure Assessment - A Cross-Cutting
Issue.
surements of delivered dose within the body to
estimate exposure.
These three approaches, when integrated for
exposure determination, can be enormously effective
in helping answer some of the most difficult
questions confronting the Agency both today and in
the future. Specific long-term objectives of the core
program include: (1) developing methodologies for
exposure measurement and modeling, (2)
characterizing representative microenvironments
on a national scale, (3) defining regional and
nationwide activity patterns, (4) measuring
exposure and body burden directly in field studies,
(5) determining the major sources of exposure
including food, dermal, and beverages - and their
contribution to risk, (6) developing and validating
exposure models and exposure-dose relationships,
(7) providing a comprehensive national data base on
exposure for use of the Agency and the
environmental community, (8) monitoring
nationwide trends and regional differences in
human exposure and activity patterns, and (9)
assessing the effectiveness of regulations by
observing these trends in total exposure.
The following sections describe the growth
envisioned in these four areas. In addition to
developing exposure assessment methods and
gathering data, the core program proposes a major
effort in the area of validation and uncertainty
assessment, to help assure that the best data,
models, and relationships are used in developing
exposure information.
Predictive Exposure Assessment Methods
YearASM)
Current
17.5
18.5 21.4 34.8 37.8 39.8
Predictive exposure assessments estimate the
location and amounts of chemicals or pollutants
41
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present (the "chemical" side) and combine them with
estimates of the location, numbers, and activities of
individuals or populations exposed (the "population"
side). This combination can be done through use of
scenarios or other devices to arrive at quantitative
estimates of exposure. Characterizing the
"chemical" side of the exposure involves assessing
fate processes and monitored concentrations,
including concentrations in so-called
"microenvironments" (see below). Characterizing
the "population" side of exposure involves activity
pattern research. Human exposure models are
usually used to combine the chemical and
population estimates. These topics are discussed
further below, along with validation.
(a) Source Characterization
Source characterization, as it relates to human
health, is the determination of pollutant
concentrations in vehicles that impact or potentially
impact individuals or populations. This information
provides the basis on which predictive exposure
models and monitoring strategies are developed.
Source characterization can also aid the hazard
identification process by providing information
concerning the extent of potential exposures.
Research in source characterization involves
chemical analysis in various media and both its
current and future emphases are indoor and
ambient air, vehicle emissions, drinking water, and
food.
(b) Fate Processes/Models
Fate processes research and its practical
application, fate model development, have been the
mainstays of predictive exposure assessment for
many years. Models are used to link releases from
sources with the resulting concentrations in
environmental media. In many cases, this research
is applicable to both human and environmental
exposures, and there is a section covering
environmental fate for ecological exposures under
"Ecological Risk." The fate work covered here is
limited to air and ground water where human
populations are the specific exposure concern. This
work will continue research into important fate
processes in these areas and the application of that
research in models.
(c) Media Monitoring for Use In Human Exposure
Assessment
This area contains analytical methods
development and monitoring. Currently, the
program is limited to monitoring in support of the
hazardous air pollutant program. The development
of real-world data for all the media is an area which
has been neglected over the last decade and has
become a critical gap in predictive exposure
assessment. It is proposed that this area be
considerably strengthened to allow much more data
to be included in predictive exposure assessments.
(d) Human Exposure Assessment Models
Predictive models for humans take several
forms; two of the major types are scenario models
(which combine the "chemical" and "population"
sides of exposure through the use of scenarios) and
microenvironmental models (which characterize the
contact as a series of exposure events of individuals
who pass through places where the chemical
concentration is relatively homogeneous
[microenvironments]). Currently, both scenario
models and microenvironmental models can be
described mathematically but suffer from a need for
realistic input data. The needed data are to be
acquired in part as described below.
Microenvironmental Studies. This proposed
research will develop data for use in the "chemical"
part of microenvironmental models. Currently,
there is very little work in this area and it needs to
be substantially expanded if the Agency is to have a
predictive tool which can readily identify the
relative media importance of chemicals.
Population Activity Patterns. Research into
activity patterns is the most critical gap in both
microenvironmental and scenario models. Currently
there is very little research in this area; it is
generally recognized by exposure assessors to be the
data gap which most seriously affects the assessors'
ability to predict "real-world" exposures. It is
proposed that studies of human activities related to
exposure to chemicals be designed and carried out to
begin filling this data gap.
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(e) Model Validation/Uncertainty Analysis.
Model validation and uncertainty analysis are
perhaps the two most widely heard requests of risk
managers when addressing exposure assessments.
This is a critical gap which must be dealt with
effectively and quickly if the exposure assessment
program is to reach its goal of providing realistic
exposure information to risk managers. Currently,
there are a few projects to validate various fate
models, but no centralized validation program. It is
a high priority of the exposure assessment program
to quickly establish such a centralized focus on
getting validation data on the models we use.
Validation is viewed as a process rather than a
single step, and models used will be in various
stages of this process for any specific use. The model
validation program can define terms and set up the
program in the short term, work through the
backlog of most-used models (both reviewing
previous validation efforts and doing further field
work if necessary) in the mid-term, and eventually
provide a working system, complete with model-
specific information, to inform assessors about how
much validation work has gone on for any given
model. The three independent methods of
determining exposure (predictive, direct
measurement, and dose estimation/reconstructive
methods) provide the Agency with a unique
opportunity to compare results as part of an overall
integrated validation program.
Direct Measurement of Exposure
Current
1.7
Year/($M)
12345
2.2 4.0 12.0 14.0 16.0
Direct measurement of exposure involves taking
measurements of the intensity of contact between a
person and a chemical while the exposure is taking
place. In addition to providing a major link to the
real world by producing actual data, it provides the
best way of answering questions such as "which
medium or exposure pathway contributes the most
to exposure?" Coupled with source characterization
"fingerprints," this multimedia research could lead
to a major improvement in our ability to determine
what sources are causing exposures in the real
world. Direct measurement research includes both
development of the instrumentation necessary to
measure exposure directly and also development of a
data base on direct measurement which can be used
to answer questions aboct media priorities for
corrective action.
(a) Instrumentation
Currently, instrumentation exists to measure
several dozen chemicals by direct measurement
techniques, but there is specific research on only one
other monitoring device. The number of chemicals
that are important to EPA decisions requires that
instrumentation be developed for many other
chemicals.
(b) Data Collection/Analysis/Management
Currently, there are data for a few dozen
chemicals taken for populations in a handful of
cities. In order to realize the potential for using these
data to make more informed decisions, a much
larger data base must be developed. In addition to
helping answer questions about exposure directly
from the data base, the data base would be used to
develop a predictive tool which can answer questions
about exposure of various segments of the
population.
Dose Estimation/Extrapolation Methods
(Exposure)
Year/($M)
Current
0.8
1.4 2.4 3.0 3.4 5.1
Recently, it has become increasingly desirable to
base quantitative risk assessment on the "delivered"
dose rather than on estimates of applied dose or
ambient concentrations. Delivered dose may be a
measure of the parent compound, metabolite, or a
biological marker that may serve as a surrogate for
the parent or metabolite. The data on body burden or
biomarker values can be used directly for exposure
assessment and can provide several important tools
to the risk manager including (1) proof that
exposure to the chemical has resulted in absorption,
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(2) the ability to reconstruct exposure levels even if
there is no longer an opportunity to measure these
levels externally, and (3) by employing
pharmacokinetic models, the capability to
extrapolate dose-risk across varying exposure
conditions (e.g., different routes, durations, dose
rates, etc.). Research efforts in the areas of
pharmacokinetics and biomarkers become the
critical components of this core area, which could
result in new tools to allow the Agency a much more
effective way to deal with situations where a local
population may have been exposed to toxic
chemicals.
(a) Pharmacokinetics
Establishing pharmacokinetic models and
developing the data needed to use these models are
the keys to deriving estimates of delivered dose
under varying exposure conditions as well as
developing reconstructive exposure assessments.
Currently, there is very little research being done; a
few PK models have been developed, but data
necessary for inputs (e.g., partition factors, local
blood flow data, etc.) and route extrapolations are
limited. This research would continue model
development, begin developing the necessary data to
run the models, and integrate these tools into the
exposure assessment process.
(b) Biomarkers
Although biomarkers have the potential of being
a direct test for exposure (obviating the need for
worst-case scenarios and bringing exposure
assessment closer to the real world), there are few
biomarkers currently that can be used routinely for
this purpose. Although current research levels are
small, pronounced growth is anticipated in research
to identify potential biomarkers of exposure and to
determine the relationships between the biomarker
levels and absorbed doses.The goal of this area of
research is to find an inexpensive and hopefully non-
invasive test which can be used in specific cases to
determine if exposure and absorption have occurred,
and to what extent, for various chemicals.
IMPLEMENTATION STRATEGY
Human health risk assessments, either explicit
or implicit, are an integral part of regulatory
decisions in all major program offices within EPA,
including: Air and Radiation; Drinking Water and
Water Quality; Toxics and Pesticides; Hazardous
Wastes; and Superfund. Although there are a
number of regulatory-specific and site-specific
questions associated with each individual program,
certain scientific issues are germane to all
programs, such as questions about environmental
concentrations, exposure and dose levels, and dose-
response relationships. All risk assessors, regardless
of program, are faced with the uncertainties
surrounding extrapolation from test species under
laboratory conditions to humans going about their
normal day-to-day activities. The goal of the core
research program in health risk assessment is to
improve the scientific basis for critical extrapolation
assumptions by carrying out key research on hazard
identification, dose-response assessment, and
human exposure assessment.
Almost $50 million is devoted to core health
research in the current budget, of which $5.4 million
is hazard identification, $24.2 million is dose-
response assessment, and $20.0 million is human
exposure assessment. Although these resources
support a substantial amount of relevant research,
there are still significant unanswered research
needs. The preceding discussion has attempted to
provide a justification for growth in specific core
research areas to meet the critical needs.
Hazard Identification. We anticipate a
relatively small increase in this area over the next
five years. Some resources in the base program will
become available for redirection as we complete
validation and refinement of certain tests. The
added resources will be used to support expansion of
research on test methods for target organ toxicity
and to refine existing methods in neurotoxicology,
reproductive toxicology, immunotoxicology,
pulmonary toxicology and heritable genetic risk.
Dose-Response Assessment. We are planning a
relatively modest, increase fcr this issue aince a
substantial portion of our program is already
devoted to this area. Efforts in dose
measurement/extrapolation will increase most
rapidly because these data will be used extensively
in subsequent development of suitable dose-response
models. Growth in biologically based dose-response
models will occur *t a gradual but sustained i ale
44
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and will emphasize incorporation of relevant
pharmacokinetic information.
Human Exposure Assessment. Research efforts
in this area will increase dramatically under our
plan. Because we have been slow to recognize the
importance of human exposure assessment, our
current activities are considered to be inadequate.
Therefore, we anticipate a very large increase in
resources that will be devoted primarily to data
collection and model validation for predictive
methods, for direct measurement methods, and for
dose estimation/extrapolation.
The following chart depicts the estimated budget
for Human Health Assessment for the current year
and five ensuing years in the future.
100-1
80 -
HEALFH RISK ASSESSMEN1
EXPOSURE
ASSESSMENT
DOSE/RESPONSE
HAZARD
IDENTIFICATION
Current
YeaM
Year 2
Year 3
Year 4
YearS
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RISK REDUCTION
INTRODUCTION
As indicated in earlier discussions, the
Environmental Protection Agency has adopted a
risk management-based approach for cleaning up
past environmental problems, managing current
sources of pollution, and minimizing the generation
of pollutants in the future. This approach utilizes
ecological risk assessment, human health risk
assessment and risk reduction. The two risk
assessment components determine the magnitude of
the risk. If the risk is unacceptable, risk reduction
offers options for reducing risk to acceptable limits.
There are three ways to approach risk reduction:
/. Pollution Prevention. The most effective way to
reduce risk is not to produce wastes and
contaminants in the first place. This involves
minimizing waste at the sources through
industrial process modifications or changes in
product design. Reclaiming usable materials
from byproduct streams and recycling spent
materials also eliminates release to the
environment.
2. Treatment. Treatment technologies are
employed to destroy, detoxify or immobilize
those wastes and contaminants that cannot be
eliminated or recycled.
3. Minimization of Exposure. Once the generation
of wastes has been reduced and undesirable
constituents treated to the optimum extent, the
remaining risk must be addressed by avoiding or
minimizing exposure (e.g., improved building
ventilation, secure land disposal, etc.).
To design regulatory and other Agency
programs that are effective, implementable, and
which produce the minimum negative impact on
society, Agency decision makers must have credible
information on the cost effectiveness and efficiency
of appropriate risk reduction alternatives. The
function of the Office of Research and Development
is to: provide that information on an array of risk
reduction alternatives; propose improvements to
available alternatives or provide new alternatives
where current ones are inadequate; anticipate
environmental and human health issues and solve
them before they reach crisis proportions; transfer
technical information to those who make risk
reduction decisions; and coordinate and stimulate
research and development on risk reduction
alternatives with academia, industry, and other
governmental agencies.
However, because the current risk reduction
research, development, and demonstration program
has emphasized short-term, program-related issues,
the following shortcomings have been in evidence:
1. EPA has focused both its regulatory and
research and development programs on end-of-
the-pipe control technologies. As a result, the
private sector has also largely focused on these
technologies. Yet, to varying degrees, these
technologies often shift risk from one medium to
another.
2. Inadequate attention has been given to risk
reduction through pollution prevention. Several
industrial firms have demonstrated that
47
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pollution prevention is more cost effective and
environmentally sound than pollution control.
3. Reliable information on the cost-effectiveness
and efficiency of specific technological solutions
is not being developed in a timely fashion.
Often, programs must be developed and
decisions made in the absence of sufficient
information on the technological risk reduction
alternatives. In some cases, technology
development lags behind the need for it.
4. There needs to be improvement in methods of
transferring technical and other information to
potential users in a way that will influence their
decision making.
EPA proposes to address these issues in the risk
reduction research and development program by
focusing an expanded research program in these
core areas.
CORE RESEARCH PROGRAM
The proposed core risk reduction research
program is designed to generate basic information
that will engender answers to such questions as:
1. What are the pollutants of concern? What are
their sources and how are they released? How do
we measure the release of the pollutants?
2. How can we prevent the generation of
pollutants? Can we design processes that do not
produce pollutants? Can we recycle or reuse
potential pollutants instead of releasing them to
the environment?
3. How can we treat, dispose of, or contain
pollutants that exist in the environment to
minimize harmful exposure?
4. How can we ensure that adequate, cost-effective
technology is available and that it is
implemented to reduce risk?
Risk reduction core capability in an EPA context
involves fundamental scientific and engineering
principles in the following areas:
1. Pollution Prevention
2. Pollution Control
3. Emerging and Neglected Issues
4. Information and Communication
The following discussion of the four risk
reduction topics summarizes the programatic utility
of the work, current core efforts, future types of core
research, and anticipated funding requirements. A
table introduces each topic with an estimate of
resources applied to the core research area currently
and for five years in the future.
Pollution Prevention
Year/S M
Current
2.4
2.4 10.0 20.0 20.0 20.0
In 1976, EPA issued its waste management
hierarchy, which stated that pollution prevention
(also referred to as waste minimization) is the
preferred approach to managing residues. While the
concept was first applied to hazardous waste, it
applies equally well to other residuals, effluents,
and emissions. As compared to end-of-pipe
treatment and disposal or dispersal, pollution
prevention has several benefits:
1. It is generally less costly than end-of-the-pipe
controls; there is less waste to manage and
dispose of resulting in smaller, often simpler,
and less costly pollution control facilities.
2. Recovery of byproducts or reduced losses of raw
materials may result in actual savings.
3. Regulatory requirements may be avoided.
4. Third-party liability problems associated with
accidents or releases may be reduced.
5. Residual risk to human health and the
environment is almost invariably reduced or
eliminated.
48
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6. It avoids shifting waste among media.
7. It applies equally well to smaller and area-wide
sources of pollution where control technologies
may be costly or difficult to implement.
Based on the success of a few larger
manufacturing companies and the obvious
advantages of this approach, EPA has been urged in
several reports to make pollution prevention a
central part of its mission. To this end, the Agency
has recently created a new office, the Office of
Pollution Prevention as a focal point for a
coordinated Agency-wide effort.
The Office of Research and Development has had
a small program for several years that has focused
exclusively on hazardous waste minimization.
Recently the program has been expanded to other
residuals, effluents, and emissions.
The following is a description of this
multimedia/multi-year research program, which
encompasses four areas - technology evaluation,
technology transfer, and data management and
trends analysis.
Technology Evaluation
Many environmental problems are caused by
processes that are inefficiently designed and
products that are ineffectively manufactured or
improperly discarded. Standardized methods are
needed for evaluating pollution-generating
characteristics of various industrial processes and
the compounds that are used in these processes.
Research is needed to evaluate redesigning products
or changing the use pattern and life cycle of products
to reduce waste.
Industry specific methods for conducting waste
minimization assessments (audits) are needed.
Promising pollution prevention strategies for
various industrial processes need to be identified.
These strategies include process modernization,
upgraded maintenance, feedstock substitutions,
spill and avoidable release prevention, recycling and
reuse options and waste stream concentrations.
To date very little attention has been given to
the pollution prevention opportunities that can
result from modifying products. Changes in product
content, form, durability, and repairability can have
significant impacts on wastes and pollutants.
Products and processes that promise to reduce total
pollution loads (e.g., usi^g less polluting feedstocks
to produce existing products, capture and recycling
of waste stream substances or producing an
alternative less harmful product) need to be
demonstrated and evaluated objectively.
Pollution prevention can be achieved through
three generic technological approaches:
Modification of Industrial Processes to Reduce
Wastes. Change of raw material feedstocks, redesign
of the process for higher efficiencies and yields, and
prevention of leaks and spills are examples of
industrial process changes that reduce the
generation of pollution. Key objectives of the
research program in this area are:
1. To develop standardized methods for conducting
assessments of waste reduction opportunities in
various industries.
2. To actually conduct model waste reduction
assessments in key industries.
3. To identify, demonstrate and evaluate, in both
new and existing industrial processes,
innovative methods for reducing pollution
generation such as process modification,
upgraded maintenance, feedstock substitution,
spill prevention and waste stream
concentration.
4. To carry out pilot scale research to facilitate the
establishment of model pollution prevention
processing facilities.
5. To identify and stimulate cross-industry
applications of innovative production and
processing technologies that reduce wastes.
Increased Recycling. Recovery, reuse, and recycling
are important options for reducing pollutants
and wastes by industries, communities and
governments. The objectives of the recycling
research program are:
49
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1. To identify, demonstrate and evaluate strategies
to increase the use of recycled materials in
products.
2. To identify and evaluate new and innovative
uses for materials that would otherwise be
discarded as wastes.
3. To evaluate the cost and performance of various
technologies to recycle, reuse and recover waste.
4. To develop guidelines for model recycling
programs.
Changes in the Design and Use Patterns of Products.
Elimination of toxic or hazardous substances in
products, increased product lifetime or
improvements in the durability or repairability of
products are ways of reducing product wastes.
Objectives for research in this area include:
1. To carry out product lifetime analyses to identify
opportunities for reducing the generation of
pollutants associated with individual products.
2. To develop criteria for evaluating specific
products to predict their pollution loads.
3. To evaluate the performance of products that
generate less wastes.
Technology Transfer
Technology transfer and technical assistance are
essential components of a research program in
pollution prevention. The success of a national plan
to encourage the development and adoption of new,
more environmentally acceptable production
processes and products depends on the quality and
effectiveness of the technology transfer and
technical assistance programs utilized to effect these
changes. To realize pollution prevention goals,
consumer and producer behaviors, attitudes, and
possibly lifestyles may require changes. As Federal,
state, and local agencies and private industries
develop and implement pollution prevention
programs, data are generated, experience is gained,
and technologies are improved. This information is
of limited value until it is assembled and distributed
in a format designed for the specific needs of the
intended users. This is where technology transfer,
technical assistance, and other outreach efforts come
into play.
These efforts provide information transfer
services, training and guidance on pollution
prevention techniques and programs, as well as
foster their acceptance and growth. There are many
mechanisms, products and services that can be
utilized. These include developing a pollution
prevention information clearinghouse which could
include telephone hotlines, electronic information
exchange networks, and hardcopy information.
Technical assistance and training techniques could
include seminars, conferences, computer animated
graphics, video tapes, computer-assisted instruction
and expert systems.
EPA would work closely with state and local
officials to identify and evaluate the efficacy of
pollution prevention activities, disseminate
pollution prevention information, and
develop/implement pollution prevention
measurement systems. In addition, EPA will
investigate pollution prevention efforts in other
countries.
Data Management and Trends Analysis
There is a need for better information on the
amounts of wastes and pollutants being generated.
There is a lack of information on the amount of
waste that results from current industrial
production and processing procedures. Thus, it is
difficult to determine how well we are doing, how we
should set our priorities and what the success has
been. Further, the potential for more reductions, and
in what industrial sectors reductions are most
likely, is not known. Hence, we have no trends
analysis and we can not measure our progress.
EPA should establish a data collection system
that measures progress in waste reduction. In
addition, waste reduction data should be multi-
media in scope, because a multi-media view is
required to assess the nature and scope of waste
reduction possibilities, set priorities, and help
determine the Federal actions that will best serve
the general public. This requires that the
government be able to determine how much waste of
all kinds is being released into all environmental
media. Existing environmental data bases such as
50
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toxic air release surveys and wastewater effluent
permits could be evaluated and incorporated into
this baseline data process.
The data management research program we
propose will address such issues as industry waste
generation and reduction data, types of waste
reduction completed, waste reduction measurement
systems, practical sources for data collection, and
methods for compiling and manipulating data. A
complementary trend analysis program can track
the effectiveness of existing programs as well as
identify the priorities for potential waste reduction
activities. The combination data management and
trends analysis programs would enable industry to
account for their waste generation and reduction
data, allow the data to be used on a multi-
media/multi-industry basis and provide a means for
the government to verify results.
Pollution Control
Year/$M
Current
2
14.5
14.5 14.5 14.5 21.0 24.3
Historically, nearly all of EPA's pollution
control research program has focused on near-term
technical needs of the regulatory development
program. As a result, there has been a lack of
emphasis on understanding the fundamental
mechanisms of pollution control.
The core research program in the pollution
control area will build the capability to explore
fundamental principles that govern pollution
control processes. For the most part, these resources
will be focused on addressing selected opportunities
to improve the state-of-the-art. To assist in defining
the problems and opportunities that can be most
fruitfully addressed, EPA will convene national
experts in each topical area to develop national
research priorities to guide core research activities.
The following discussions identify areas in which we
plan to focus attention.
Thermal Destruction and Combustion
Understanding the scientific principles of
combustion is important because incineration
(thermal destruction) has become the most common
waste treatment technique. Furthermore,
combustion of fossil fuels is most often used to
generate heat and power. Understanding the
fundamental principles of combustion and thermal
destruction can result in the development of
technologies which do not produce adverse
byproducts (air emissions and ashes), thereby
providing risk reduction alternatives with
significantly lower, more acceptable levels of risk.
Thermal Destruction. Fundamental work in this
area will improve our ability to predict and
minimize products of incomplete combustion (PICs),
understand and control the fate of metals, and
understand and predict the fundamental
relationships between waste characteristics,
physical characteristics, and operation conditions of
unit processes, and the resulting residues. This
information will help industries improve their
capability to design cost-effective incinerators and
predict emissions produced with different wastes,
fuel composition, and operating parameters. This
will lead to improved waste incinerators that have
an acceptable risk.
Fuel Combustion. Current research is aimed at
understanding the mechanisms of N2O formation in
the flame zone and developing design parameters for
low NOX heavy oil burner nozzles. Expansion of this
program will result in a comprehensive under-
standing of how to increase fuel (coal, oil, gas, wood)
combustion efficiency while decreasing the
production of gaseous pollutants (SC>2, NOX, N2O,
HC1) and particulates. Research will also be
conducted on new or improved techniques such as
catalytic devices to minimize formation or enhance
destruction of unwanted byproducts. This know-
ledge will lead to improved fuel combustion devices
which reduce the amount of air emissions and
thereby reduce unacceptable adverse environmental
(e.g., acid deposition) and human health risks.
In addition to work associated with utility and
industrial fuel combustion, effort will be focused on
heating by woodstoves and kerosene heaters. The
nature and extent of indoor pollutant emissions and
51
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their control via design modifications will be
investigated.
Physical Separation
Under the broad topical heading of physical
separation, there are a multitude of processes used
mainly in water and wastewater treatment and in
air pollution control. Many of these processes have
been used for a long time, e.g., sand filtration,
electrostatic precipitation, and fabric filters. Others,
such as ultrafiltration are newer. Although
improvements in the cost effectiveness of these
processes should be possible, opportunities involving
emerging environmental issues warrant early
attention. These include source separation and
central facility classification of municipal solid
wastes, and evaluation of basic approaches to indoor
air cleaners. Specific research efforts will address
separation of metals and organic constituents from
drinking water; separation of contaminants from
wastewater and sludges; separation of solid wastes
to facilitate recycling or treatment; and separation
of particulates from gas streams.
Biological Processes
There is both a long successful history and a
bright future for the use of biological processes in
the environmental field. Sewage and industrial
organic wastes have long been treated by biological
means (e.g., activated sludge). The use of
genetically engineered organisms and new reactor
designs promises improved cost effectiveness of
these processes. In-situ treatment of contaminated
soils and ground water using acclimated natural and
genetically engineered microorganisms promises to
revolutionize spill and Superfund cleanup activities.
Another potential application is in the treatment of
trace organics in municipal water supplies.
Biological degradation processes offer tremendous
potential for improvements in effectiveness and
substantial cost savings when treating relatively
low concentrations of organic contaminants in
wastewater, groundwater, and water supplies.
There is still a lot to learn and a focused effort should
yield substantial benefits. The initial focus of this
work will be on:
Identifying microorganisms with significant
potential for biodegrading wastes and
pollutants,
Evaluating how to deliver and disperse the
microorganisms effectively,
Determining how to maintain their viability in
the field,
Determining how to monitor and track
remediation progress.
In addition, the production and use of biological
agents in the economy, particularly genetically
engineered organisms, poses technical and
regulatory control challenges for the Agency. EPA is
responsible for registering and approving these
agents. There is a need for an R&D program
investigating release and dispersal of these
organisms. The core research program will look at
technical issues involving the production and use of
commercial genetically engineered microorganisms.
Chemical Processes
Chemical processes are used in a variety of
environmental applications including separation of
contaminants from water (e.g., via precipitation),
destruction of biological agents (e.g., in drinking
water disinfection), and immobilization of
contaminants (e.g., metal fixation in soils). While
improvements can be made to many of these
processes through better understanding of the
fundamental principles governing them, the largest
untapped potential appears to be in chemical
destruction of organic constituents in hazardous
waste, and in-situ immobilization of metals and
destruction of organic contaminants in soil and
ground water. Optimization of these processes to
achieve their potential will involve improving
surface reactor designs and finding ways to enhance
distribution of chemicals in the subsurface
environment (e.g., by electrokinetics). Initially, the
core program will focus resources on these areas, in
addition, research will focus on improved under-
standing of chemical destruction of organic contam-
inants in soil and debris, chemical destruction of
biological agents in drinking water and wastewater,
chemical separation of contaminants in drinking
water and wastewater, and chemical stabilization
52
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and immobilization of contaminants in soils and
wastes.
Containment
Containment is a broad topic involving
separation of harmful materials using some form of
barrier. It includes such diverse activities as
containing contaminated materials in tanks, drums,
and landfills, minimizing dispersion of airborne
material (e.g., minimizing asbestos dispersal by
using encapsulants), minimizing migration of
contaminants into buildings (e.g., by using sealants
to stop radon entry), and use of protective clothing to
protect workers from contaminated environments.
One neglected area warranting further
attention is separation of waste contaminants in
landfills from the environment using liners and
caps. The RCRA reauthorization legislation of 1984
mandated use of complex liner and cap systems and
these systems have begun to be installed over the
past few years.Protection of human health and the
environment depends on the long-term effectiveness
of these systems, yet there is little information on
their longevity. The core research program will
initially focus on fundamental study of the key
factors that determine the performance of liner and
cover systems such as chemical compatibility, micro-
biological and UV resistance, and subsidence. The
program will also address problems such as seam
stress cracking and develop ways of monitoring cap
performance.
Another important area for early years is
research directed at understanding the physical and
chemical integrity of solidified and stabilized
wastes. We must be able to measure, both short-term
and long-term, whether the wastes are truly con-
tained by such processes and therefore unable to be
released into the environment.
Other areas of potential research involve
furthering our understanding of the physical and
chemical mechanisms associated with devices for
containing pollutants from soil, for example,
geosynthetic membranes, slurry walls, and clay
liners; preventing exposure in contaminated areas
through improved protective clothing; developing
effective technologies for reducing indoor contam-
inant levels; furthering our understanding and
effectiveness in containing and collecting small
fibers such as asbestos; improving our knowledge of
the mechanisms that lead to failure of underground
storage tanks; and enhancing our ability to create
more effective devices of this type.
Source Characterization
This area covers the research needed to
characterize the pollutants (type, amounts and rate
of release) from a variety of sources. This
information is necessary to conduct risk assessments
and to develop cost effective risk reduction
alternatives. Although considerable knowledge
exists about "conventional pollutants from common
sources," much is unknown about toxic pollutants
and microbial agents from many new sources. These
sources need to be generically characterized by
appropriate groups and classes, and emission factors
and models need to be developed.
We recognize two general types of sources:
(a) point sources such as industrial furnaces,
effluent discharge pipes, and incinerators, and
(b) areal or dispersed sources, such as agricultural
and urban runoff and natural sources and sinks. The
technologies, necessary skills, measurement
equipment and even the manner in which one
approaches characterization of these two kinds of
sources varies somewhat.
The current program contains work on charac-
terization of point source emissions from industrial
furnaces, hazardous waste facilities, and municipal
solid waste combustors. An expansion of this work
will result in the capability to characterize pol-
lutants from high to very low concentrations for
organics, inorganics and microbials; to characterize
the rate of release of pollutants from treatment/
disposal facilities; to characterize any changes in the
composition of pollutants during release; and to
predict emission and contaminant levels under
different environmental/climatic conditions. This
core research will lead to a better understanding of
the composition and release rates of pollutants and
improve efficiency in developing, evaluating and
selecting risk reduction alternatives.
Very little work is underway to characterize
emissions from dispersed area-wide sources.
Research is necessary to develop an understanding
53
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of the chemical, biological and physical mechanisms
that govern the release of gaseous and particulate
materials from a variety of sources (nonpoint source
agricultural runoff, methane gas from marshes,
natural vegetation sources of volatile organic
compounds, emissions of alkaline dust and
ammonia, etc.). This core research will lead to a
better understanding of the composition and release
of areal pollutant sources. With this new knowledge,
the uncertainty in risk assessments for global
climate change, stratospheric ozone depletion, acid
deposition, wetlands and other sensitive ecosystems,
and ozone nonattainment will be reduced.
Emerging and Future Issues
Year/$ M
Current
2
5
4.5
4.5 5.6 5.6 16.8 21.0
Effective environmental protection depends on
the timely development of reliable risk reduction
solutions. Typically, research and development
resources are not focused on risk reduction options
until after an environmental issue has been defined
fully. Delay in the availability of appropriate
reduction strategies and technologies can result in
risk reduction solutions which are insufficiently
protective and/or overly costly. Long-term impacts
may not be anticipated and alternative solutions to
problems may go unexplored.
We must begin to address risk reduction
alternatives much earlier in the evaluation process,
once an unacceptable risk is suspected but before it
has been fully explicated. If we wish to address
emerging environmental issues more constructively
than we have in the past, risk assessment and risk
reduction research and development cannot be
performed in a strictly sequential fashion. Risk
reduction research must evolve as issue definition
evolves, starting with generic anri fundamental
studies of the possible solutions.
Moreover, in order to identify future issues long
before they become crises of public concern, we must
focus efforts on analyzing environmental trends,
tracking changes in ambient concentrations of
environmental contaminants, and evaluating new
production technologies and new products.
Following is a description of the two areas in
which we plan to conduct core research:
Emerging Issues
Several emerging issues are receiving
inadequate research and development attention.
Research and development are necessary so that
performance and cost information will be available.
Following is a short compilation of these issues:
A. Municipal Solid Waste. Research needs to
address the many environmental questions that
remain unanswered relative to landfill and
incineration options; they include groundwater
contamination potential from landfills and
hazardous air and solid residues from
incinerators. Resource recovery options also
need to be carefully analyzed.
B. Global Climate and Stratospheric Ozone
Depletion. Risk reduction research is needed to
identify affordable technological and non-
technological options to reduce emissions of CC>2,
CFCs and other important contributors to global
warming and/or stratospheric ozone depletion.
C. Nonpoint Source Contaminants. As urban areas
grow and agriculture becomes more dependent
on chemicals, nonpoint source contamination of
ground and surface waters become more
widespread. The Agency plans to work
cooperatively with USDA, academia, and the
private sector to identify and evaluate promising
prevention options and transfer successful
technologies to users.
D. Medical/Infectious Waste. Careless disposal of
medical wastes could lead to unacceptable risks
to public health. The Agency needs to establish a
core research capability to evaluate the efficacy
of various transportation, handling, and disposal
options.
E. Water Supply. As population grows, especially in
arid areas, there is increasing pressure to reuse
finite water supplies. Focusing on reuse, the
54
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Agency should expand its modest program to
include the identification and evaluation of cost-
effective water treatment technologies. Also, we
need to evaluate new approaches for reducing
water use and for obtaining alternative water
supplies (e.g., desalination).
F. Indoor Air. Concern grows regarding the quality
of the air within our homes and buildings. The
current program for evaluating emissions from
construction materials needs to be expanded.
There is also a need to evaluate other sources
including combustion appliances and household
chemicals. A pollution prevention and control
program must be initiated with the aim of
providing mitigation guidance to the public.
G. Alternative Fuels. As the nation attempts to deal
with its ground-level ozone and CC>2 pollution
problems, pressure will mount to use alternative
motor vehicle fuels such as methanol. Questions
about the pollution that may result from the
production of these fuels as well as from their
use remain unanswered. Careful research
attention must be paid to the implications of this
switch to alternative fuels. Emission
characterization of both the mobile sources and
the production processes is necessary.
H. Environmental Infrastructure. The nation faces
a major problem with the aging and decay of its
infrastructure, including water delivery
systems, sewers and wastewater treatment
plants. The Agency plans to conduct research
aimed at identifying opportunities for
incorporating pollution prevention practices as
the infrastructure is replaced. For example,
water savings may be possible, allowing smaller
sewers to be built into existing ones, yielding
major savings in infrastructure replacement.
Future Issues
All too often, environmental issues are thrust
upon EPA from outside by citizen concern, by
Congress, or in some cases, by the academic
community. Rarely is EPA the first to identify an
issue as problematic. Yet early identification of
issues should be central to EPA's mission. The
earlier issues can be identifed, defined, and solutions
found and implemented, the sooner EPA's mission to
protect human health and the environment is
realized. EPA can identify issues before they become
crises of public concern, but it must focus on doing
so. There are several ways of proceeding:
A. Environmental trends. Demographic, economic,
infrastructure (e.g., transportation), foreign
trade, and other trends can be analyzed to
determine potential environmental impacts.
Enhanced ability to predict the environmental
impacts of major trends would allow us time to
perfect technologies to either minimize negative
impacts or enhance positive impacts. This type
of research is and should continue to be
conducted primarily by the Office of Policy
Planning and Evaluation, in coordination with
research activities and the program/regional
offices.
B. Ambient concentrations. The ambient
concentrations of pollutants in the environment
can be tracked over time for insight into future
trends. This subject is discussed in both the
human health and ecological risk assessment
chapters and is not generally in the purview of
the risk reduction program. The trends
identified in the environment would be used in
targeting and planning the risk reduction
research. Also, this program may allow
monitoring of the overall effectiveness of various
control options as they are implemented. Over
the longer term, it is really the reduction in
ambient concentration that is important, not the
specific reduction in each point or nonpoint
source.
C. New production technologies and products. New
production technologies and products can
radically affect both the characteristics and
amounts of emissions and residues. Use and
disposal of new products or products with new
components can also create (or reduce)
environmental problems. These technological
trends can be monitored and characterized. The
engineering community is best able to do this
because of its day-to-day contact and familiarity
with the industrial production community. Once
production technology or product trends are
characterized as significant producers of new
contaminants or increased volumes of
55
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contaminants, further investigation of the
potential risks can be conducted by others. The
primary goal of this research is to identify and
predict changes in releases of contaminants into
the environment due to changes in production
processes and products.
Information and Communication
Vear/$M
Current
1.2
13. 2.5 2.5 3.0 3.0
The selection and implementation of viable, cost
effective, risk reduction approaches is influenced by
a variety of legal, scientific, economic, political, and
social factors. Just having scientific information
that an unacceptable risk exists or that a technology
exists to reduce that risk to an acceptable level does
not ensure that appropriate risk reduction actions
will be taken.
Waste generation and waste management
decisions are driven by non-technological forces
including behaviors, incentives, and benefits.
Behaviors are complex patterns of human activity
that result from habits, beliefs, knowledge, and
economic pressures. Behaviors may be altered when
sufficient incentive exists to change habits, abandon
beliefs, investigate new ideas, or pursue improved
economic conditions. Perceived benefits to
individuals, groups, corporations or industries can
motivate altered behavior in ways that reduce waste
generation or discharge. Therefore, information
about behaviors, incentives, and benefits is a key
tool to be used in directing the development and
implementation of mechanisms for reducing the
generation of pollutants and improving the
management of waste. Research in these non-
technological areas may reveal significant
opportunities for reducing pollution.
Research areas will include:
A. Risk Communication. How people perceive risk
and what that means for efforts to communicate
risk information to the public and to
decisionmakers will be studied. Research will
focus on methods for placing diverse risks in
perspective, the social and cultural content of
communication about risk, the factors affecting
the acceptability of a risk analysis, presenting
uncertainty in information for the public and
policymakers, and the factors impeding
consensus among experts. This research would
lead to improved policies and environmental
decisions.
Another important area of research that relates
to risk communication is the need to develop
consensus-based methods of problem solving and
policy making. Examples include development
of the regulatory negotiation process and the use
of alternative dispute settlement techniques in
the enforcement program and in the Superfund
cleanup program.
B. Incentives and Disincentives. Risk reduction
strategies are designed to induce changes in
behavior leading to the prevention of pollution
or the resolution of existing environmental
problems.
Research is needed to identify the factors
bearing on the decision to comply (or not to
comply) with regulatory requirements.
Examples of this type of research include topics
such as methods and motivation of corporate
environmental management in their compliance
with regulatory requirements, effectiveness of
deterrence strategies for environmental
regulation, importance of the availability (or
lack) of information and resources that could be
alleviated by improved education and technical
assistance, organizational barriers to effective
environmental programs, and use of decision
theory and decision analysis to gain insight into
likely corporate responses to environmental
programs.
Research must also address the relative
effectiveness of alternative strategies. One
principal topic is the effectiveness of such
56
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incentive approaches as marketable permits,
emission fees or charges, taxes, or subsidies.
A third area will explore why people do or do not
take action to reduce risks within their control
and explains what factors influence these
choices. Several emerging problems stress the
importance of individual or group level behavior
and the importance of a non traditional,
nonregulatory approach. These problems
include residential radon and other indoor air
problems, lead in homes, use of pesticides and
other chemicals in homes, in farming, and other
occupational practices. These problems
highlight the need for research on
understanding behavioral change in individuals
and firms. A related area is research on
understanding how to get people to reduce risk
through exposure avoidance. This is important
for environmental issues such as the protection
of pesticide applicators and asbestos abatement
workers, land use planning and industrial
siting.
C. Technical Information Dissemination. The
objective of this research is to explore new
mechanisms and/or improve existing methods of
delivering scientific and engineering
information. Historically, technology transfer
has been accomplished through written
materials (reports, summaries, journal articles,
design manuals, handbooks, workbooks) and
orally through seminars, workshops, and
training courses. Research is needed to evaluate
innovative state-of-the-art mechanisms such as
expert systems, computer animated graphics,
computer-assisted instruction packages
containing workbooks and computer disks, and
laser disk technology. The end products will be
(1) guidance on how to select the appropriate
technology transfer approaches for particular
types of technical information and for specific
user communities and (2) the actual
development of innovative technology transfer
systems. Development and demonstration of
these systems will be accomplished in
partnership with the private sector.
D. Commercialization and Utilization. New
technologies must be commercialized to be
successful. A variety of incentives and
disincentives work to either promote or inhibit
this process. These include market size,
competition, need for permits, resistance to first
use, and information availability on these and
other decision-making criteria. Research carried
out in the core program will identify and analyze
the relative importance of these incentives and
disincentives and design strategies to control
their impact. The major products from this
research will be expert systems to assist
developers to identify the necessary actions
required for commercialization. Support for the
environmental technology commercialization
system will ultimately reduce the time it takes
to get new or improved environmental
technologies into the marketplace.
E. Education and Training. EPA must take the
lead on integrating environmental protection
goals into the nation's business, science, and
engineering curricula. Traditionally, industrial
process engineers have been taught to maximize
productivity, optimize quality, and reduce costs
of production. We need to instill as well an
understanding of and appreciation for the
environmental and human health impact
potential of their products, processes, and
residuals.
It is critical that EPA, private industry, trade
and professional associations, and universities
work together to develop materials that teach
environmental management. We need to
support the development and implementation of
environmental education programs at all levels,
i.e., from grade school, to graduate school, to on-
the-job training.
Educational programs can help explain how
each and everyone has a role in protecting our
environment. Our educational process must
include information on the environmental
impacts of this society's actions. EPA should
work actively with scientific and professional
organizations to advocate including
environmental considerations in all types of
industrial, scientific, and engineering actions.
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IMPLEMENTATION STRATEGY
Priorities for the risk reduction core research
program are to begin a major effort in pollution
prevention in year two, and add a significant
increment in year three. This is because pollution
prevention is the most effective long-term strategy
for accomplishing significant additional reduction in
risk levels. Initiation of a full program is critical if a
multimedia effort is to be implemented across the
three major pollution prevention components:
technology evaluation, technology transfer, and
data management and trends analysis. An expanded
program will work with all Agency programs,
including solid wastes, pesticides, toxic substances,
wastewater, water supply, radiation, nonpoint
sources, and air emissions.
The next priority will be to expand significantly
our capability in year two in the area of information
and communication research and development. The
primary areas for initial growth in the ORD
program are research on new or improved methods
for technical information dissemination, technology
commercialization and utilization, and risk
communication.
The work on emerging and neglected issues will
begin to grow in year two and then expand rapidly in
years four and five. An orderly expansion is planned.
Work on municipal solid wastes and global climate
will be increased early because of the apparent
magnitude of these issues. Indoor air
research and mitigation development will be next to
receive focus. Medical and infectious wastes will also
receive early attention. Work on nonpoint source
contamination, water supply, energy conservation
and alternative fuels, and environmental
infrastructure will be fully in place by year five.
As indicated previously, opportunities in
pollution control technology and in the
identification of future environmental issues
promise large dividends if sufficient resources can be
applied. A major expansion is planned beginning in
year four.
SUMMARY
The risk reduction research program must be
expanded rapidly in the early years to initiate high
priority work in pollution prevention. The
identification of emerging issues and research on
communication techniques will then begin steady
expansion, followed by significant research on
pollution control. The following chart depicts the
estimated Office of Research and Development
budget for risk reduction research for the current
year and 5 years into the future. However, much of
the research described in the information and
communication area is performed by other Agency
offices. We anticipate that expansion in these areas
will be accommodated by budget requests outside
the scope of this proposal.
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70 -I
60 -
50 -I
O 40 -
RISK REDUCTION RESEARCH
INFORMATION AND
COMMUNICATION
EMERGING ISSUES
POLLUTION CONTROL
POLLUTION
PREVENTION
Current Year 1 Year 2 Year 3 Year 4 Years
59
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EXPLORATORY GRANTS AND
ACADEMIC RESEARCH CENTERS
INTRODUCTION
The single most important resource in our
national environmental research and development
strategy is the environmental scientists and
engineers themselves. The proposals presented
throughout this core research plan are predicated on
the existence of a skilled environmental research
community. To this end, EPA must assume
responsibility for supporting and sustaining the
nation's academic environmental research
community and institutions.
As the Science Advisory Board stated in its
recent report entitled Future Risk: Research
Strategies for the 1990 's, "The more the scientific
community at large understands about EPA's
scientific goals and projects, and the more EPA's
scientists know about research outside the Agency,
the greater the benefit to our national effort as a
whole."
Exploratory Grants
Year/$M
Current
2
8.0
18.0 30.5 38.0 50.0 50.0
One key mechanism for delivering this type of
support is through investigator-initiated grants to
the colleges and universities where these
professionals receive their education and do their
research. Previous experience demonstrates that our
success in mounting large applied research
programs depends on stable, reliable support for
individual researchers, largely in academia.
External grants programs are invaluable in
stimulating the generation of fundamental
knowledge from which applied programs derive new
information. Without the steady infusion of new
ideas, we run the risk of overmining our data base.
Grants programs provide excellent training
opportunities for young scientists and engineers in
graduate and post-doctoral settings who are our
future researchers and managers. And, finally,
grants to academic environmental researchers
increase the probability that problems and their
possible solutions are discovered earlier, making
remediation cheaper. When fully attained, the core
program will provide approximately 200 new grants
per year, with a total of 500 grants in place at any
given time. Grants will be awarded in five
environmental areas: health, biology, engineering,
and chemistry and physics related to air and water.
Maintenance at this new level of $50.0 million
should ensure that researchers can commit
themselves and their graduate students to research
careers of interest and benefit to EPA, and be
confident of extended funding if they perform well.
Academic Research Centers
Year/$M
Current
1
2
4.5
4.5 4.5 7.0 10.0 10.0
A concomitant element of our effort to
strengthen EPA's links to the external scientific
community will be to create additional academic
61
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research centers to address those areas of
environmental research which are best served by
longer-term institutional arrangements. In the past
such areas have included ecological risk, coastal
ecology, epidemiology, etc., where longer, larger,
and more focused efforts have been required than
could be achieved through grants to individuals.
Future centers will be focused on specific issues
selected by EPA to complement and enhance the
EPA research program, and to augment EPA
expertise.
IMPLEMENTATION STRATEGY
The grants program we propose to mount will
grow by significant increments in the first four years
and then level off in year five at $50.0 million. The
centers program will expand in both the second and
the fourth years of this five-year scenario.
A graph depicting current and projected
resources follows.
60 -
40 -
Z
o
RESEARCH GRANTS
ACADEMIC
RESEARCH
CENTERS
EXPLORATORY
GRANTS
20 -
Current
Year 1
Year 2
Year 3
Year 4
Years
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APPENDIX A
EXPOSURE ASSESSMENT
A CROSS-CUTTING ISSUE
INTRODUCTION
Exposure assessment has been termed the weakest
link in risk assessment. The practice of exposure
assessment attempts to quantify the real world contact
(exposure) of agents and organisms and the subsequent
absorption into the organism (dose) so that this
information can be used in dose-response relationships
to predict risk. The overall goal of the exposure
assessment program is to provide accurate exposure
information for Agency risk managers and decision
makers to use in risk assessment and risk management.
Whenever risk-based decisions are made in the
Agency, there is uncertainty associated with the risk
estimates. Although the hazard identification and dose-
response areas of risk assessment contain
uncertainties, we often deal with certain chemicals in
many different decisions, and the uncertainty in the
hazard identification and dose-response for these
chemicals will be consistent among decisions. For
exposure assessment, on the other hand, each decision
usually considers different exposure situations, forcing
new evaluations of uncertainty for exposure for each
decision. Furthermore, and perhaps even more
importantly, all the Agency's risk reduction strategies
involve the reduction of exposure either by reducing
concentrations contacted or by modifying activities
which result in contact, since toxicity and dose-response
relationships for a given chemical are, for the most part,
not modifiable. For these reasons, accurate exposure
assessments provide the fundamental basis for the
Agency's risk-based decisions, including risk reduction
strategies used in risk management.
Many of the questions which Agency decision
makers face daily have answers directly based on sound
exposure assessments. Some typical examples are:
1. Will the risk to the surrounding community
increase if an incinerator is sited here, and if so, by
how much?
2. Which of the 15 known sources of this particular
chemical should be controlled to most effectively
reduce risk?
3. Have the people living in the area of this Superfund
site been exposed to the hazardous substances at the
site, and if so, how much?
4. How is the risk to the population in a given area
changing over time, especially, have any of the
controls I put in place succeeded in reducing risk?
CORE RESEARCH PROGRAM
This core research proposal outlines a program that
will result in an integrated approach to exposure
assessment, using real world data both directly and to
derive validated relationships among several major
approaches to exposure assessment: predictive, direct
measurement, and reconstructive.
Exposure assessors have often used all of the major
approaches to quantify exposure. The predictive
approach characterizes the chemical and the organism
separately, then estimates exposure by linking them
through devices such as scenarios or
microenvironments. The direct measurement approach
uses measuring devices at the point of contact to
monitor the intensity of contact while it occurs. The
reconstructive approach uses measurements inside the
organism after the exposure has occurred to try to
reconstruct what the exposure and absorbed dose must
have been at some time in the past. All of these
approaches have particular strengths for answering
certain types of questions of interest to the decision
makers.
Predictive exposure assessments, when based on
real world data and validated models, are best at
answering "what if' questions such as question one
above. Direct measurement data, in addition to
providing an actual measurement of exposure, best
answer questions about which routes of exposure (and
63
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ultimately, perhaps even which sources) are the most
important in terms of the actual exposure received (e.g.,
question two above).
Reconstructive assessments offer proof that
exposure and absorption have occurred and therefore
are best at answering questions about the actual status
of an individual's or a group's exposure (e.g., question
three above). All these approaches, used together in an
integrated approach to exposure determination, can be
effective in helping answer some of the most difficult
questions confronting the Agency both today and in the
future (including questions such as the four above).
In addition to developing exposure assessment
methods and gathering data, the core program proposes
a major effort in the area of validation and uncertainty
assessment, to help assure that the best data, models,
and relationships are used in developing exposure
information.
The program is described in terms of four topics:
Predictive exposure assessments, direct measurement
of exposure, reconstructive exposure assessment, and
validation/integration/uncertainty. Each of the topics
has issues associated with it. The program covers both
human and ecological exposure assessments. As a
crosswalk among the Human Risk Assessment,
Ecological Risk Assessment, and Risk Reduction Core
Research Programs, this presentation shows the
relationships among the various exposure-related
topics found in those programs.
Predictive Exposure Assessments
Year/$M
Current
1
33.1
45.1
116.7 132.2 137.5 150.0
Predictive exposure assessments estimate the
location and amount of chemicals or pollutants present
(the "chemical" side) and combine them with estimates
of the location, numbers, and activities of individuals or
populations exposed (the "population" side). This
combination can be achieved through the use of
scenarios or other devices to arrive at quantitative
estimates of exposure. In order to characterize the
chemical, knowledge of sources, environmental fate,
and concentrations in various media (or
microenvironments) is necessary. Models are often used
to interconnect these, but accurate characterization of
the location and concentration of pollutants depends a
great deal on real-world measurements. Models and
environmental measurements work together in a
predictive assessment; the models theoretically
describe why the concentrations are what they are, and
the measurements are the link to the real world.
The research involved in characterizing the
"chemical" side of predictive exposure is the foundation
upon which both the human and the ecological
predictive exposure assessments are based and applies
equally to human and ecological exposure.
Characterization of the location and activities of the
exposed population (the "population" side of predictive
exposure) can also use models, but again, observations
or measurements of activities provide the real-world
link.
Finally, exposure models in predictive assessments
link the "chemical" and the "population." These models
can use any of a number of devices for making that link,
among them exposure scenarios, microenvironmental
information, or Monte Carlo techniques.
Source Characterization
Year/$ M
Current
9.0
9.4
13.1
14.0
14.3
15.6
The current program contains some research for
mobile sources and a minor amount of research for
other sources. It is proposed that this be expanded to
sources such as building materials, consumer products,
and other indoor air sources as well as to outdoor
sources such as incinerators.
Accurate release rates are important data in most
fate models. Eventually, this research may lead to the
ability to "fingerprint" sources.
Fate Processes/Models
Current
6.4
1
7.4
2
9.4
Year/$ M
3
11.2
4
12.0
5
13.0
Fate processes research and its practical
application, fate models, have been the mainstays of
predictive exposure assessment for many years. Many
64
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processes, however, are still poorly understood, and
models are also needed in certain areas. The expansion
of research in this area will emphasize metal speciation,
partitioning processes (both physical and biological) for
organics, and bioconcentration.
Media Characterization
Year/* M
Current
12.1
22.1
85.3
90.9
93.0
98.0
This area contains analytical methods develop-
ment and monitoring. Currently, the program is limited
to monitoring in support of the air (hazardous air
pollutants) program. The development of data for all
the media has been neglected over the last decade and
has become a critical gap in predictive exposure
assessment. It is proposed that this area be the focus of
a major new environmental research initiative: the
establishment of an operational monitoring system for
media status and trends. This system is discussed more
fully under Ecological Risk. (See EMAP discussion
pages 25 through 27.)
Microenvironmental Studies
Currently there is very little research in this area; it is
generally recognized by exposure assessors to be the
data gap which most seriously affects the assessors'
ability to predict "real world" exposures.
Environmental Exposure Models
Year/$ M
Current
1.0
1.0
2.0
2.0
2.0
7.0
Currently, estuarine, water quality, terrestrial, and
large lakes models are being developed. These models
are not being routinely used by the Agency for
ecological risk assessments, however. The research
proposed will be an expansion to complete and test
these models (and perhaps other ecological models) so
that the Agency can better perform ecological risk
assessments.
Human Exposure Models
Year/$ M
Current
3.9
3.9
4.5
5.5
6.2
7.0
Year/$ M
Current 1
0.2 0.5
2
0.9
3
3.5
4
4.5
5
4.5
This proposed research will develop data for use in
the "chemical" part of microenvironmental models (see
Human Exposure Models below). Currently there is
very little work in this area. If the Agency is to have a
predictive tool which can readily identify the relative
media importance of chemicals, the data from these
types of studies must be developed.
Population Activity Patterns
Current
0.5
1
0.8
3
1.5
Year/5 M
3
5.1
4
5.5
5
5.5
Research into activity patterns is the most critical
gap in both microenvironmental and scenario models.
Currently, both scenario models and micro-
environmental models can be described mathe-
matically but suffer from a need for realistic input data.
Putting these models into the hands of assessors
through PC-based, menu-driven programs, along with
the backup data needed to run the models, is the goal
here. Currently there is very little work in this area.
Use of state-of-the-art technology (such as CD-ROM)
may revolutionize the assessors' access to real data in
the next few years, provided the data are developed.
Direct Measurement of Exposure
Year/$M
Current 1
1.7 2.2
2
4.0
3
12.0
4
14.0
5
16.0
Direct measurement of exposure involves
measuring the intensity of contact between a person
and a chemical while the exposure is taking place. In
addition to providing a major link to the real world by
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producing actual data, it provides the best way of
determining which medium or pathway is the most
important for exposure. Coupled with the source
characterization "fingerprints" described above, this
research could lead to a major improvement in our
ability to determine what sources are causing
exposures.
Instrumentation for Direct Measurement of
Exposure
Current
0.0
1
0.5
2
0.7
Year/$ M
3
1.5
4
2.0
5
2.0
Currently, instrumentation exists to measure
several dozen chemicals by direct measurement
techniques, but there is specific research on only one
other monitoring device. The number of chemicals that
are important to EPA decisions requires that
instrumentation be developed for many other
chemicals.
Data Collection/A nalysis/Management
Year/$ M
Current 1
1.7 1.7
2
3.3
3
10.5
4
12.0
5
14.0
Currently, there are data for a few dozen chemicals
taken for populations in a handful of cities. In order to
realize the potential for using these data to make more
informed decisions, a much larger data base must be
developed. In addition to helping answer questions
about exposure directly, the data base would be used to
develop a predictive tool which can answer questions
about exposure of various segments of the population.
Reconstructive Exposure Assessment
Year/$M
Current
0.8
2.4
7.4
8.0
8.4
12.1
Reconstructive exposure assessment involves
taking measurements from inside an organism after
exposure has taken place and relating the
measurements (through pharmacokinetic relation-
ships) to what exposure must have been in the past to
result in these measured levels. Potentially, these
assessments can be the best way to ascertain whether
exposure has occurred.
Biomarkers of Exposure - Human
Year/$ M
Current 1
0.7 1.0
2
1.2
3
1.5
4
1.7
5
2.9
Although these biomarkers are potentially a direct
test for exposure (obviating the need for worst case
scenarios and bringing exposure assessment closer to
actual exposures), there are few biomarkers now that
can be used routinely for this purpose. Current research
levels are small and are proposed to be greatly
increased to do research into identifying potential
biomarkers of exposure and determining the
relationships between the biomarker levels and
absorbed doses.
Biomarkers of Exposure Ecological
Year/$ M
Current
0.0
1.0
5.0
5.0
5.0
7.0
Currently, there is virtually no work being done in
this area, although potentially the use of ecological
biomarkers of exposure could result in rapid assessment
of actual exposure status of both plants and animals.
Pharmacokinetics/PK Models/Data
Current
0.1
1
0.4
2
1.2
Year/$ M
3
1.5
4
1.7
5
?.?
Pharmacokinetics is the key to reconstructive
exposure assessment. Currently there is very little
research being done; a few PK models have been
developed but none of the necessary data (partition
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factors, local blood flow data, etc.) are generally
available.
Validation, Integration, and Uncertainty
models (both the review of previous validation efforts
and further field work, if necessary), and
eventuallyprovide a working system for assessors to use
to determine how much validation work has taken place
for any given model.
Year/$M
Current
0.9
1
1.3
2
2.0
3
5.6
4
8.6
5
11.8
Model validation and uncertainty are perhaps the
two most widely heard requests of risk managers when
addressing exposure assessments. This is a critical gap
which must be dealt with effectively and quickly if the
exposure assessment program is to reach its goal of
providing realistic exposure information to risk
managers.
Model Validation
Current
0.4
1
0.8
2
1.4
Year/$ M
3
4.0
4
7.0
5
10.0
Currently, there are some projects to validate
various fate models but no centralized validation
program. A high priority of the exposure assessment
program is the establishment of a centralized focus for
getting validation data on the models we use.
Validation is viewed as a process rather than a single
step, and models used will be in various stages of this
process for any specific use.
If established, the model validation program, can
define terms, work through the backlog of most-used
Integrated Approaches
Year/$ M
Current
0.2
0.2
0.3
0.8
0.8
0.8
With three independent methods for determining
exposure, the Agency has a unique opportunity to
compare results from each method as part of a
validation effort. This effort is currently operating at a
very small level of resources and is proposed to expand
somewhat in the future.
Uncertainty Analysis
Current
0.3
1
0.3
2
0.3
Year/$ M
3
0.8
4
0.8
5
1.0
The current program has a small effort in this area.
The proposed program would expand the research into
how uncertainty analysis can be used for exposure
assessment and what the risk managers and decision
makers want to see in the way of uncertainty analysis.
The following tables and chart depict budgetary
resources in exposure assessment for current and
ensuing years.
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200 -4
EXPOSURE ASSESSMENT
150-
VALIDATION
RECONSTRUCTIVE
EXPOSURE ASSESSMENT
DIRECT MEASUREMENT
PREDICTIVE/ AMBIENT
MONITORING
Current Year 1 Year 2 Year 3 Year 4 Year 5
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