United States Science Advisory EPASAB-EC-90-021A
Environmental Protection Board September 1990
Agency (A-101)
/'/ ^ • ' -
?/EPA The Report Of
The Ecology And Welfare
PROTECTION
Relative Risk
Reduction Project
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NOTICE
This report has been written as part of the activities of the
Science Advisory Board, a public advisory group providing
extramural scientific information and advice to the Administrator
and other officials of the U.S. Environmental Protection Agency.
The Board is structured to provide a balanced expert assessment of
scientific matters related to problems facing the Agency. This
report has not been reviewed for approval by the Agency; and,
hence, the contents of this report do not necessarily represent the
views and policies of the Environmental Protection Agency or other
agencies in the Federal Government. Mention of trade names or
commercial products does not constitute a recommendation for use.
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ABSTRACT
The Ecology and Welfare Subcommittee of the Relative Risk
Reduction Strategies Committee (RRRSC) of the U.S. Environmental
Protection Agency's Science Advisory Board (SAB) reviewed the
ecological and welfare components of the Agency's 1987 report
entitled "Unfinished Business: A Comparative Analysis of
Environmental Problems". The Subcommittee was critical of the
original EPA ranking of environmental problem areas that mixed
sources, receptors, media, and specific regulatory obligations,
since this categorization reflected EPA programmatic interests more
than it provided a rational basis for evaluating environmental
problems in the United States. In addition, some ecologically
significant problems that were outside of EPA's regulatory purview
were omitted. The Subcommittee was also critical of the welfare
effects analysis, finding it to be defined too narrowly
The Subcommittee developed alternative methodologies for
evaluating ecological and welfare risk assessments: a) aggregation
of related EPA environmental problem areas into a more limited
number of categories and then ranking those categories; and b)
disaggregation of the initial EPA environmental problem areas into
environmentally-relevant categories of stresses and then ranking
those categories. The ecological problem areas that were
consistently ranked the highest by the Subcommittee were habitat
alteration, global climate change, and stratospheric ozone
depletion.
The Subcommittee developed six major recommendations from its
review of the Unfinished Business report: a) formalize an
extramural and continuous process for ecological risk
prioritization; this process should not be categorized by Agency
programmatic structure but rather by anthropogenic stresses on the
environment; b) invest in development of formal methodologies for
ecological risk assessment; c) develop the data bases needed for
improving future ecological risk assessments; d) develop an
appropriate methodology for integrating ecological and economic
time dimensions; e) EPA should give more consideration to non-
economic aspects of ecological values and welfare risks; f)
consider the results from this risk ranking process, including the
1990 risk reduction study, in development of future Agency policy
and in allocation of financial resources.
The Subcommittee reached a strong consensus that the relative
risk assessment process is a good mechanism to formulate public
policy from a scientific base of data and mechanistic processes and
recommended that the Agency institutionalize this approach on a
regular basis, providing the trained personnel and scientific data-
bases needed to establish a scientific credibility for the process.
Key Words; ecological risk assessment; risk reduction; welfare
risk assessment
ii
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U.S. ENVIRONMENTAL PROTECTION AGENCY
SCIENCE ADVISORY BOARD
RELATIVE RISK REDUCTION STRATEGIES COMMITTEE
Ecology and Welfare Subcommittee
Chairman
Dr. William Cooper, Chairman, Zoology Department, Michigan State
University, East Lansing, Michigan
Members
Dr. Yorum Cohen, Associate Professor of Chemical Engineering,
University of California at Los Angeles, Los Angeles,
California
Dr. Steven Eisenreich, Professor of Environmental Engineering,
University of Minnesota, Minneapolis, Minnesota
Dr. Mark Harwell, Director, Global Environmental Programs, Cornell
University, Ithaca, New York
Dr. Dean Haynes, Professor of Entomology, Michigan State
University, East Lansing, Michigan
Dr. Robert Huggett, Director, Virginia Institute of Marine Science,
College of William and Mary, Seaford, Virginia
Dr. Ronald Olsen, Professor of Microbiology and Associate Vice
President for Research, University of Michigan Medical
School, Ann Arbor, Michigan
Dr. David Reichle, Associate Director of Bioroedical and
Environmental Sciences, Oak Ridge National Laboratory,
Oak Ridge, Tennessee
Dr. June Lindstedt-Siva, Manager of Environmental Science, ARCO,
Los Angeles, California
Science Advisory Board Staff
Mr. Robert Flaak, Acting Assistant Director, U.S. EPA, Science
Advisory Board, Washington, DC
iii
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY 1
2.0 INTRODUCTION 5
2.1 Background 5
2.2 Charge to the Ecology and Welfare Subcommittee . . 6
2.3 Format of this Report 6
3.0 ENVIRONMENTAL PROBLEM AREAS 9
3.1 Limitations of EPA List of Environmental Problem
Areas 9
3.2 Ranking of Aggregated Environmental Problem Areas . 12
3.2.1 Air Quality 12
3.2.2 Surface Water 14
3.2.3 Soil 14
3.2.4 Habitat Alterations 14
3.2.5 Groundwater 15
3.2.6 Waste Sites 15
3.2.7 Accidental Releases 15
3.2.8 New Chemicals and New Technology .... 15
4.0 ALTERNATIVE MODEL 16
4.1 Summary of the Disaggregation Approach 16
4.2 List of Environmental Stresses Considered by the
Subcommittee 17
4.3 Ecological Risk Evaluations 17
4.3.1 Ecosystem/Stress Response Matrix .... 17
4.3.2 Environmental Stress Rankings by Scale . 20
4.3.3 Environmental Stress Rankings by Medium . 22
4.3.4 Ecological Recovery Times 22
4.4 Summary of Ecological Risks 25
5.0 WELFARE RISK ANALYSIS 28
5.1 Background 28
5.2 Subcommittee Findings 28
5.2.1 Critique of Appendix IV 29
5.2.2 Sustainability 30
5.2.3 willingness to Pay 31
5.2.4 Multiplier Concept 32
5.3 Welfare Risk Paradigm 33
5.3.1 Ecological Quality 33
5.3.2 Resource Sustainability 33
5.3.3 Direct Effects - Economics 34
5.3.4 Direct Effects - Non-Economic 34
5.4 Welfare Risk Rankings of the Subcommittee 34
6.0 UPDATES ON RISK CATEGORIES 37
6.1 Criteria and Toxic Air Pollutants 38
6.2 Radiation from Sources Other than Indoor Radon . . 39
6.3 Stratospheric Ozone Depletion 40
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6.4 Global Climate Change 42
6.5 Direct and Indirect Point Source Discharges to
Surface Waters 45
6.6 Non-Point Source Discharges to Surface Waters
Plus In-Place Toxics in Sediments 46
6.7 Contaminated Sludge 48
6.8 Physical Alteration of Aquatic Habitats 49
6.9 Active Hazardous Waste Sites 50
6.10 Inactive Hazardous Waste Sites 51
6.11 Municipal and Industrial Non-Hazardous Waste
Sites 53
6.12 Alteration and Disturbance of Terrestrial
Habitats 55
6.13 Accidental Releases of Toxics 56
6.14 Oil Spills 57
6.15 Underground Storage Tanks 58
6.16 Groundwater Contamination 59
6.17 Pesticides 60
6.18 New Toxic Chemicals (Non-Pesticides) 61
6.19 Biotechnology 62
6.20 Plastic in the Marine Environment 65
6.21 Biological Depletion and Extinctions 66
6.22 Introduction of Biologic Species 67
7.0 RECOMMENDATIONS AND CONCLUSIONS 68
REFERENCES CITED 71
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LIST OF TABLES
Table I Developing a Hierarchy of Relative Risk .... 2
Table II Assessing Welfare Risks 3
Table III Original EPA List of Environmental
Problems 10
Table IV Classification of Problem Areas Relative
to Size, Hazard, and Exposure 13
Table V Ecological Risk Matrix 18
Table VI List of Ecosystem Types 19
Table VII Ranking of Ecological Risks Characterized
by Scale of Stress 21
Table VIII Summary of Ecological Risk Rankings
(From Tables VII, IX, & X) 23
Table IX Ranking of Ecological Risks Characterized
by Medium 24
Table X Time for Ecological Recovery 26
Table XI Integrated Welfare Rankings 36
VI
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1.0 EXECUTIVE SUMMARY
This is the report of the Ecology and Welfare Subcommittee of
the Relative Risk Reduction Strategies Committee (RRRSC) of the
U.S. Environmental Protection Agency's Science Advisory Board
(SAB) . As part of the overall activities of the RRRSC, the
Subcommittee reviewed the Agency's 1987 report entitled "Unfinished
Business: A Comparative Analysis of Environmental Problems" (EPA,
1987a,b,c), hereinafter referred to as Unfinished Business, in
order to provide a peer-review and update of that document, develop
alternative methodologies for evaluating ecological and welfare
risk assessments, and combine ecological and welfare rankings of
relative risk into a single aggregate ranking.
The Subcommittee members were unanimous in their
dissatisfaction with the original EPA list of problem areas that
mixed sources, receptors, media, and specific regulatory
obligations (see Table III, page 10). In the Subcommittee's view,
this categorization reflects EPA programmatic interests far more
than it provides a rational basis for evaluating national
environmental problems. In addition, the Subcommittee identified
some significant environmental problems that were outside of EPA's
regulatory purview and that had been excluded from the original
list of problem areas (e.g., habitat alteration and depletion of
species).
The Subcommittee strongly endorses the use of a matrix of
ecological stress types versus ecosystem types as developed by
Harwell and Kelly (1986) (see Table VI, page 19). We utilized our
evaluations of the intensity of potential effects, the
uncertainties of these estimates, the type of ecological responses,
and the time scales for recovery following removal of the stress
as diagnostic parameters. Once the hierarchy of relative risk was
established, we aggregated the problem areas as to scale of stress
(local, regional, biosphere), transport media (air, water,
terrestrial), and recovery time (years, decades, centuries/
indefinite) (see Table I, next page).
The ecological problem areas that we consistently ranked the
highest were habitat alteration , global climate chance, and
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Table I - Developing a Hierarchy of
Relative Risk
Diagnostic Parameters
Aggregated Problem Areas
Intensity of Potential Effect*
Uncertainties of these Estimates
Type of Ecological Responses
Time Scale for Recovery
Following Removal of Stress
Scale of Stress (local, regional
biosphere)
Transport Media (air, water,
terrestrial)
• Recovery Time (years, decades,
centuries/Indefinite)
stratospheric ozone depletion (see Table VIII, page 23) . The time-
space dimensionality of all three are similar. The ecological
impacts are locally, regionally, and globally distributed, and the
recovery times are estimated to be up to centuries. Ecological
systems are well adapted to recover from many types of stresses as
long as the impacted areas are patchy in distribution and
asynchronous in time. This allows for genome refugia that
constitute sources for recolonization once the stress is removed.
Loss or disturbance of natural habitats increases the rate of
biological depletion, which is the other problem area of high
concern. The extinction of biologic species is an irreversible
event with unknown, but long-term impacts. It is virtually
impossible to ensure the survivorship of a species if its habitat
cannot be protected.
The Subcommittee ranked the problem areas of airborne toxics.
toxics in surface waters, and pesticides and herbicides in the
second highest category of relative risk (see Table VIII, page 23).
We gave emphasis to toxic substances (heavy metals and organics)
that are transported by air and water and may be bioaccumulated in
ecological food chains. Generally, these stresses do not cause
irreversible impacts, but they do deplete the quality of the
ecological resources and definitely interfere with the human uses
of specific populations. The rapid transport processes in air and
the large number of point and non-point discharges to surface
waters generate local and regional impacts. The recovery times
after the sources are removed are measured in multiple decades.
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The Subcommittee discussed in depth the assessment of welfare
risks. We felt that the traditional practice of discounting the
values of impacts in time makes no sense ecologically. We defined
four types of welfare impacts: ecological quality, resource
sustainabilitv. direct effects-economic, and direct effects-non
economic (Table II). The ecological impacts are mediated through
ecological processes and, therefore, the welfare and ecological
rankings are similar. The resource sustainability impacts involve
changes in the environment that are irreversible or of very long
duration relative to human perspective. Again, the impacts are
often mediated through ecological processes and, therefore, the
welfare rankings are a sub-set of the long-duration ecological
effects (this includes the issue of groundwater contamination).
Table II - Assessing Welfare Risks
Types of Welfare Impacts
Ranked
Definition
Ecological Quality
Indirect impacts on human* that result
from a reduced quality of an
environmental resource and decreased
human utility (Reversible)
Resource Sustainability
yes
Irreversible losses of ecosystem
structure and functions, such as loss
of critical habitat or species extinctions
Direct Effects - Economic
no
Direct physical changes that cause
adverse economic Impacts on humans
other than health effects
Direct Ef f ects-Non Economic
yes
Primarily Involves social nuisances such
as odors, noise, and reduced visibility
The direct effects-economic risks could not be ranked as the
data needed to perform a credible benefit/risk analysis are not
available. The Subcommittee did rank the direct effects-non
economic risks. These involve noise, odor, vistas, and
psychological impacts that are not easily quantified and for which
no environmental standards exist.
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We recognize that the authority to implement programs to
address the environmental problems of greatest concern is
distributed widely across the federal and state governments and,
thus, beyond the mandate of the U.S. EPA. The Agency, however, is
the only Federal agency whose primary mission is to "speak for the
environment." The Agency must take an aggressive leadership role
in demonstrating to other governmental institutions the risks and
benefits of sound environmental planning and management.
The Subcommittee developed six major recommendations that
result from our review of the Unfinished Business report and from
our present evaluation of the environmental problems that were
identified in Unfinished Business:
a) Formalize an extramural and continuous process for
ecological risk prioritization; this process should not be
categorized by Agency programmatic structure but rather by
anthropogenic stresses on the environment.
b) Invest in development of formal methodologies for
ecological risk assessment.
c) Develop the data bases needed for improving future
ecological risk assessments.
d) Develop an appropriate methodology for integrating
ecological and economic time dimensions.
e) EPA should give more consideration to non-economic aspects
of ecological values and welfare risks.
f) Consider the results from this risk ranking process,
including the 1990 risk reduction study, in development of future
Agency policy and in allocation of financial resources.
The Subcommittee developed a strong consensus that the
relative risk assessment process is a good mechanism to formulate
public policy from a scientific base of data and mechanistic
processes. We recommend that the Agency institutionalize this
approach on a regular basis, and provide the trained personnel and
scientific data-bases needed to establish a scientific credibility
for the process.
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2.0 INTRODUCTION
2.1 Background
In its 1988 report on research strategies for the 1990's,
"Future Risk", the Science Advisory Board recommended that the
concept of risk reduction be used more broadly in EPA (SAB, 1988).
As a follow-up to that report, EPA Administrator William K. Reilly
requested that the SAB bring its technical expertise to the task
of developing risk reduction strategic options that will assist him
in assessing possible Agency activities. In response to this
request, the SAB formed the Relative Risk Reduction Strategies
Committee (RRRSC).
A major portion of the RRRSC's work involves consideration of
the 1987 EPA report "Unfinished Business: A Comparative Assessment
of Environmental Problems" (EPA, 1987a,b,c). This EPA document
reports on the findings of EPA senior staff who evaluated more than
two dozen environmental problems in terms of their relative
environmental risks. These problems were evaluated within four
broad categories: cancer risk, non-cancer health risk, ecological
risk, and welfare risk.
To evaluate these issues, the RRRSC formed three
subcommittees. The Human Health Subcommittee was formed to
evaluate the cancer and non-cancer health risks; the Ecology and
Welfare Subcommittee was formed to evaluate the ecological and
welfare risks; and the Strategic Options Subcommittee was formed
to develop and evaluate risk reduction strategies. The charge to
the SAB, through its RRRSC and three associated subcommittees, was
to:
a) Provide a critical review of the "Unfinished Business"
report that reflects any significant new information that bears on
the evaluation of the risks associated with specific environmental
problems.
b) Provide, to the extent possible, merged evaluations of
cancer and non-cancer risks (i.e., health risks) and of ecological
and welfare risks (i.e., environmental risks).
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c) Provide optional strategies for reducing major risks.
d) Develop a long-term strategy for improving the methodology
for assessing and ranking risks to human health and the environment
and for assessing the alternative strategies that can reduce risks.
2.2 Charge to the Ecology and Wai far* aMbC9HunitttT
This document was prepared by the Ecology and Welfare
Subcommittee, a subcommittee of the Relative Risk Reduction
Strategies Committee (RRRSC) of the U.S. Environmental Protection
Agency's (EPA) Science Advisory Board (SAB). The tasks taken on
by this Subcommittee were: a) to provide a peer review of the
procedures utilized and the rankings obtained from the EPA
activities in 1986-87 that led to the EPA report entitled
"Unfinished Business: A Comparative Assessment of Environmental
Problems"; b) to update the background papers presented in
"Appendix III - Ecological Risk Work Group" (of the "Unfinished
Business" report) and re-evaluate the ecological rankings based on
this new information; c) to critique the procedures presented in
"Appendix IV - Welfare Risk Work Group" (of the "Unfinished
Business" report) and to develop an alternative approach for
evaluating welfare risks, if possible; and d) to combine the
ecological and welfare rankings of relative risk into a single
aggregate ranking that could then be compared with the human health
rankings.
2.3 Format of this Report
In addition to an Executive Summary, an Introduction, and a
list of cited References, this report contains five major sections.
Section 3.0. Environmental Problem Areas, represents a further
aggregation of the programmatic areas into eight general areas of
environmental problems. The Subcommittee members were unanimous
in their dissatisfaction with the original EPA list of problem
areas that mixed sources, receptors, media, and specific regulatory
obligations. This categorization reflects EPA programmatic
interests more than it provides a rational basis for evaluating
environmental problems in the United States. In addition, it
omitted some problems of ecological significance that were outside
of EPA's regulatory purview.
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As a first step beyond the 1986 procedures carried out by EPA,
the Subcommittee examined the original 31 EPA categories of
environmental problem areas. Some of these were combined when we
felt there were no differences in ecological risk (e.g., municipal
and industrial non-hazardous waste sites); others were added when
an important ecological risk was not covered in the 1987 EPA report
(e.g., alteration and disturbance of terrestrial habitats). The
second step was to combine the list of problem area categories into
eight functional groups and to rank their relative impacts in terms
of the potential severity of the hazard and spatial extent of
effects.
Section 4.0. Ecological Risk Assessment Model, presents a very
different model for producing ecological risk assessment. This
approach follows that developed by Harwell and Kelly (1986), which
was included in Appendix III of the Unfinished Business report.
This model starts with the basic scientific understanding of stress
agents and ecological responses across the variety of anthropogenic
activities, affecting the ecological systems of the United States.
Several different scenarios of risk rankings were investigated.
These included the rankings based on scale of stress (ecosystem,
regional, biosphere), the transport media (air, water, or
terrestrial), and the ecological recovery time (years, decades,
centuries, or nonrecovery time). These detailed rankings provided
the basis for a summary ranking of environmental stresses with
respect to ecological risk.
Section 5.0. Welfare Risk Analysis, critiques the "Appendix
IV - Welfare Risk Assessment" and presents an alternative paradigm.
Four classes of welfare impacts were identified: Ecologically
Mediated; Resource Sustainability; Direct Effects - Economic; and
Direct Effects - Non-economic. Rankings were produced for three
of these classes of welfare effects. The "Direct Effects -
Economic" category requires specific economic data that were not
available to the Subcommittee. Thus, no attempt was made by the
Subcommittee to develop an economic ranking. A summary of welfare
risk rankings combining the aspects of the other three categories
was developed.
Section 6.0, Updates on Risk Categories, contains critiques
of the problem areas, providing additional information to update
these topics.
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Section 7.0. Recommendations and Conclusions, presents six
major recommendations developed by the Subcommittee to assist the
Agency's capability to assess environmental risks.
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3.0 ENVIRONMENTAL PROBLEM AREX8
3«1 Limitations of EPA List of Environmei
The Subcommittee was asked to address the EPA-specified list
of the thirty-one environmental problem areas (initially developed
for the EPA Comparative Risk Project - see Table III, page 10) in
order for its results to be comparable with other evaluations
(i.e., Human Health and Strategic Options Subcommittees). However,
it was clear to the Subcommittee that the listed problem areas were
not categorized in parallel, and that the criteria for selecting
the items on the list were not primarily related to potential types
of environmental stresses. Specifically, these listed problem
areas are much more attuned to programmatic considerations within
EPA than they are to actual environmental problems in the real
world. For instance, waste sites are separated into four
categories (active hazardous sites, inactive hazardous Superfund
sites, non-hazardous municipal sites, and non-hazardous industrial
sites) ; each category is divided based more on how they are
regulated within EPA than on the types of stresses they may impose
on the environment. Furthermore, the EPA list of problem areas is
inconsistent with respect to the level of resolution of the
classification. For example, one category includes all inputs to
estuaries, coastal waters, and oceans from all sources, whereas
another category consists only of accidental releases from oil
spills.
Consequently, individual categories of the thirty-one
environmental problem areas often contained many different types
of environmental stresses. For example, EPA Environmental Problem
Area 1 includes "criteria pollutants", i.e., those pollutants
identified in the Clean Air Act for which National Ambient Air
Quality Standards (NAAQS) are required (specifically, sulfur
dioxide, nitrogen oxides, ozone, carbon monoxide, lead, and
particulates). The types of ecological stresses associated with
this single category vary widely, from local-scale deposition of
a heavy metal, for which the primary concern is ecological routes
to humans, to the transboundary-scale problem of acid deposition,
which has the potential for significant ecological effects on
freshwater and terrestrial ecosystems involving pH stress, aluminum
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Table III - Original EPA List of
Environmental Problems
1 - Criteria air pollutants from mobile & stationary sources; acid deposition
2 - Hazardous/toxic air pollutants
3 - Other air pollutants, (e.g., flourldes, total reduced sulfur)
4 - Radon (Indoor pollution only)
5 - Indoor air pollution (other than radon)
6 - Radiation (other than radon)
7 - Substances suspected of depleting stratospheric ozone layer
8 - Carbon dioxide and global warming
9 - Direct point-source discharges to surface waters - Industrial sources
10 - Indirect point-source discharges to surface waters - POTW's
11 - Non-point source discharges to surface water plus In-place
toxics In sediments
12 - Contaminated sludge (Includes municipal and scrubber sludges)
13 - Discharges to estuaries, coastal waters, and oceans from all sources
14 - Discharges to wetlands from all sources
15 - Drinking water at the tap (Includes chemicals, lead from
pipe, biological contaminants, radiation, etc)
16- Active hazardous waste sites (Includes hazardous waste
tanks, Inputs to groundwater and other media)
17 - Inactive hazardous waste sites (Includes Superfund, Inputs
to groundwater and other media)
18 - Municipal non-hazardous waste sites (Inputs to groundwater & other media)
19 - Industrial non-hazardous waste sites (Includes utilities)
20 - Mining wastes (e.g., oil and gas extraction wastes)
21 - Accidental releases of toxics (all media)
22 - Accidental releases from oil spills
23 - Releases from storage tanks (Includes product & petroleum tanks)
24 - Other groundwater contamination (septic tanks, road salt, Injection wells)
25 - Pesticide residues on food eaten by humans or wildlife
26 - Application of pesticides (Includes risk to pesticide workers as
consumers who apply pesticides)
27 - Other pesticide risks (leaching, run-off, air deposition from spraying)
28 - New toxic chemicals
29 - Biotechnology (environmental releases of genetically altered organisms)
30 - Consumer product exposure
31 - Worker exposure to chemicals
Modified from: EPA Report "Unfinished Business: A Comparative Assessment
of Environmental Problems" pages 10-11. (EPA, 1987a).
10
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toxicity, changes in redox potential, enhanced susceptibility to
disease and pest infestations, differential effects on competitive
interactions in ecological communities, and a host of other
problems. Thus, the relative risks to the environment from this
single category would entail an amalgamation of quite disparate
stresses, spanning: a) many spatial scales of the extent of
exposure; b) many different levels of hazard to ecological systems,
and c) many different modes of action for toxicity or other impacts
on ecological systems. It is inappropriate to assign a single
level of risk to such a diversity of environmental stresses.
Moreover, a single value assigned to such a broad category of
stresses does not provide the decision-maker with information on
the relative importance of the diversity of stresses within the
category, unnecessarily losing much useful information that could
be derived from the environmental risk ranking process.
Another difficulty with the EPA problem area classification
is that many individual types of environmental stresses from
anthropogenic activities were categorized into more than one of the
thirty-one environmental problem areas. As one example, the
potential ecological impacts from xenobiotic organic chemicals that
are toxic to biota could be associated with the EPA-listed
environmental problem areas 1, 2, 3, 9, 10, 11, 12, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, 27, and 28 (see Table III, page 10).
Because of this considerable degree of redundancy for a single type
of environmental stress across the EPA categories of environmental
problem areas, relative ranking of environmental risks would be
impossible without knowing the relative distribution across the
problem areas of the magnitudes of the stress. Following the same
example, if it were determined that xenobiotic organic chemicals
are a major risk to the environment, do all nineteen of the above
listed problem areas rank high?
We decided that alternate approaches to environmental risk
ranking are required. Two tacks were taken: 1) aggregation of
related EPA environmental problem areas into a more limited number
of categories, followed by ranking of those categories based on
Subcommittee-developed criteria; and 2) disaggregation of the
initial EPA environmental problem areas, with addition of other
stresses of concern, into environmentally-relevant categories of
stresses, followed by ranking of the new categories based on
Subcommittee-developed criteria. The first approach, discussed in
the following sections, has the advantage of being directly related
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to the EPA list being considered by the Human Health and Strategic
Options Subcommittees. The second approach, detailed in Chapter
4, has the advantage of allowing examination of relative risk
rankings established with regard to spatial scale, transport media,
or other criteria, thereby preserving the considerable information
and expertise used to evaluate environmental risks.
Although the ranking in the Unfinished Business report was
provided for all of the thirty-one problem areas, it appears that
the differentiation in the ranking among various problem areas was
not clearly substantiated. Consequently, the Subcommittee
aggregated the problem areas into groups based on the following
considerations:
a) the spatial extent of the area subjected to the stress;
b) the importance of the ecosystem that is actually affected
within the stressed area;
c) the potential for the problem to cause ecological effects
and the ecological response;
d) the intensity of exposure; and
e) the temporal dimension of both effects and the potential
ecological recovery.
Factors a) and b) were classified as global, regional, or
local in scale. A higher priority was given to areas under the
global classification. Factor c) was classified as either high,
medium, low, or unknown. Finally, factors d) and e) were
classified as high, medium, or low. For both factors c) and d),
a higher priority was given to problem areas that were classified
as high. The classification of the problem areas according to the
above factors is given in Table IV (see page 13). The rationale
for the grouping of problem areas is given below, with the original
number of the related EPA environmental problem in parentheses.
Note that some problem areas (4,5,6,15,24,26,30 and 31) are not
included since we did not consider them ecologically significant.
3.2.1 Air Quality (Environmental Problems 1-3,7,8)
Although one might be tempted to separate global warming (8)
and stratospheric ozone (7) from criteria air pollutants (1) and
hazardous air pollutants (2), the fact remains that all of the
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Table IV - Classification of Problem Areas
Relative to Size, Hazard, and Exposure
Aggregated
Problem Areas
Air Quality
Surface Water
Soil
Phys. Alteration
Groundwater
Waste Sites
Accident. Release
New Chemicals &
New Technology
Original a
Problem Areas
1,2,3,7,8
9,10,11,20
12,25,27
13,14,20
23,29
16,17,18.19
21,22
28,29
Size
Global
Glob/Reg
Regional
Local
Local
Local
Local
?
b
Hazard
High
High
High
Low-HI
Low
Low
?
?
Exposure
High
High
High
N/A
Low
Low
Low/Hi
?
a This column lists the original problem areas as numbered in the
"Unfinished Business Document: A Comparative Assessment of
Environmental Problems". Note that problem areas 4,5,6,15,24,26,
30 and 31 were not considered as having an ecological impact.
b Defined as the inherent ability to cause harm.
N/A « Not applicable for this problem area
? » Unknown
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above are closely linked to emissions (3) from chemical processes,
energy generation, and non-stationary sources. For example,
hydrocarbons play an important part in the generation of
atmospheric ozone and hydrogen peroxide as well as the generation
of sulfates and, thus, acid rain. Burning of fossil fuels leads
not only to the increase in carbon dioxide levels that affect
global warming but also to the emission of non-methane hydrocarbons
that play an important role in controlling the levels of criteria
pollutants. Thus, from the point of view of sources, air quality
is a rational grouping that encompasses problem areas 1,2,3,7,& 8.
3.2.2 Surface Water (Environmental Problems 9-11.20)
Environmental problem areas 9-11 include direct (9) and
indirect (10) point and non-point (11) discharges to surface
waters. Problem area 20 (mining wastes) can also be considered as
a potential contributor to surface water contamination. Thus,
areas 9-11 and a component of area 20 are best grouped under the
surface water category.
3.2.3 Soil (Environmental Problems 12.25.26)
Problem areas 25 and 26 consider pesticides. Since pesticides
are applied onto the soil environment, the direct effect is on soil
and vegetation. Subsequently, the movement and accumulation of
pesticides through the food chain are important, and there can be
a significant effect on wildlife. Contaminated sludge that is
disposed of or treated in the soil environment leads to a direct
contamination of the soil environment and subsequent migration to
other systems (e.g., groundwater) . Thus, from the viewpoint of the
environmental medium that is directly affected, Items 12, 25, and
26 should be classified as a single category*
3.2.4 ffflfritflt Alterations (Envirqnfflfrntfl1 Problems 13»14.20)
Environmental problem areas 13 and 14 consider the physical
alteration of aquatic habitats and are therefore grouped together.
Problem area 20, which is concerned with mining wastes, could be
partially in this category given that mining activities and mining
waste can lead to physical habitat alteration. Thus, regardless
of the affected media, habitat alteration should be considered as
a single group.
14
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3.2.5 Qroundvatar (Bnv^rpnm^ptal Problems 23.29)
Problem areas 23 and 29 consider release from storage tanks
and other groundwater contamination sources. Since groundvater
protection is the focus, groundwater should be the category of
concern.
3.2.6 Waste Sites (BnvjT9nffl?Trtfll Problem Areas 16-19)
Environmental problem areas 16-19 involve various types of
waste sites and, thus, should be grouped under the same category.
3.2.7 Accidental Releases (Environmental Problem Areas 21.22)
Accidental releases of toxics (21) and oil spills (22) are
both in the category of accidental releases and should be
considered under the same class.
3.2.8 New chemicals and New Technology (Environmental Problem
Areas 28.29)
Biotechnology (29) and the category of new chemicals (28)
represent new ventures that are designed for the introduction of
new materials or chemicals. Since there is a lack of information
regarding the potential effects from these unknown sources of
potential contaminants, problem areas 28 and 29 are grouped into
a single problem area. It is important to note that although this
area was ranked lowest in priority, this was largely because of the
lack of knowledge about this potential future problem area which
at present hinders a rational ranking. However, in order to
minimize future pollution problems, an effort must be maintained
to identify potential ecological impacts that may be associated
with new chemicals and processes whether chemical or biological.
15
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4.0 ALTERNATIVE MODEL
4.1 ymnparv of the Disacrcrreqation Approach
The second approach that the Subcommittee used to improve the
environmental risk assessment methodology involved the
disaggregation of the EPA environmental problem areas into
environmentally relevant stresses. The Subcommittee decided to
adopt the approach developed by the original panel of outside
ecological experts convened during the initial EPA Comparative Risk
Project. This panel met in October, 1986, and prepared a separate
report (Harwell and Kelly, 1986; also included in Appendix III of
the "Unfinished Business" Report (EPA, 1987b) ) that detailed a
methodology for ecological risk ranking. Specifically, that
original panel: 1) considered the EPA list of thirty-one problem
areas and eliminated areas with no ecological relevance (e.g.,
Problem Area 4, indoor exposure to radon); 2) identified and
categorized specific types of environmental stresses associated
with each environmental problem area on the EPA list; 3) identified
additional environmental stresses that were not included in the EPA
list, including items that may not presently be within EPA purview
for regulation or management; 4) developed a list of ecological
systems categorized with respect to the nature of stress responses
or recovery; 5) developed a matrix of environmental stresses versus
ecosystem types, with each cell in the matrix containing an
evaluation of the potential and magnitude of ecological effects and
recovery; and 6) utilizing this matrix and a set of panel-developed
criteria discussed below, ranked the list of environmental stresses
with respect to potential environmental risks.
The present Subcommittee adapted the previous panel's
methodology as follows: 1) modified the panel's list of
environmental stresses with minor wording changes in the names of
a few categories (e.g., substitution of hazardous in place of
toxic) and the addition of one category (species depletion); 2)
reevaluated the potential ecological risk from each environmental
stress (differentiated across scales of stress [local to global])
and modified the similar matrix from the previous panel's report,
with attention to new information or understanding not available
at the time of the 1986 deliberations; 3) developed a new matrix
16
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of ecological risks of the environmental stresses differentiated
by transport medium (air, water, and terrestrial); and 4) collapsed
these two ecological risk matrices into a synthesis ranking of
relative ecological risks from environmental stresses.
4.2 List of Environmental Stresses Considered by t^fif SMfrC^HUBJttTT
The Subcommittee began with the list of environmental stresses
presented in Harwell and Kelly (1986). The list was reconsidered
with respect to the need for wording changes as well as any missing
environmental stresses that should be added. A revised list was
prepared by the Subcommittee; this list can be directly related to
the original EPA list of thirty-one problem areas using the matrix
in Table V (see page 18). This matrix indicates those
environmental stresses that were not included in the EPA list of
problem areas, as well as a few problem areas that had been
combined by EPA in the Unfinished Business Report. The matrix also
separates the environmental stress agents by source.
4.3 Ecological Risk Evaluations
4.3.1 Ecosvstem/Stress Response Matrix
The panel of ecological experts convened in 1986 (Harwell and
Kelly, 1986) categorized ecosystems of interest into ecosystem
types based on the potential for differences in ecosystem responses
or recovery from stress. This list of ecosystem types was accepted
by the Subcommittee without revision (Table VI, see page 19).
The potential for ecological effects from each environmental
stress were estimated by the original panel of experts using the
following factors (Harwell and Kelly, 1986):
1) The potential intensity of ecological effects, evaluated
as high, medium, low, or no effect; this expert judgment estimation
was based in part on the background information provided by EPA to
the panel, but was primarily based on the expertise and experience
of the ecological panel.
2) The nature of the ecological effect from each specific
environmental stress, categorized as: a) potential effects on
biotic community structure, such as alterations in the trophic
structure, changes in species diversity or richness, or other
17
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Table VI - List of Ecosystem Types
Freshwater Ecosystems
- buffered lakes
- unbuffered lakes
- buffered streams
- unbuffered streams
Terrestrial Ecosystems
- coniferous forests
- deciduous forests
- grassland ecosystems
- desert & semi-arid ecosystems
- alpine and tundra ecosystems
Marine and Estuarine Ecosystems
- coastal ecosystems
- open ocean ecosystems
- estuaries
Wetland Ecosystems
- buffered freshwater Isolated wetlands
- unbuffered freshwater Isolated wetlands
- freshwater flowing wetlands
- saltwater wetlands
community-level indicators of disturbance; b) potential effects on
ecological processes, such as changes in rates of primary
production, nutrient cycling, decomposition, and other important
ecological processes; c) potential effects on individual species
of particular direct importance to humans, e.g., species with
particular aesthetic or economic value, or endangered or threatened
species; and d) the potential for the ecosystem to function as a
vector for routes of exposure to humans of chemicals or organisms
having potential health-effects concerns.
3) The degree of certainty associated with these estimations,
differentiating those circumstances where the data and
understanding are sufficient for certain or probable projections
to be made versus the situation of either poorly understood stress-
response relationships or of highly infrequent occurrence of
adverse responses; and
4) The probable time scale for recovery to occur following
cessation of the stress, estimated as years, decades, centuries,
or indefinite time for recovery.
19
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In the original ecological panel's ranking, a matrix of the
environmental stress agents versus ecosystem types was developed
with expert judgment on each of these four factors (intensity of
potential effects, type of ecological response, uncertainties about
the estimate, and time scale for ecological recovery) (Table 4 in
Harwell and Kelly, 1986). The present Subcommittee did not
reexamine every element in this matrix. Rather, the Subcommittee
examined the summary ranking (Table 7 in Appendix III of the
"Unfinished Business" Report) of the ecological stresses divided
by spatial scale that was developed based on the detailed
ecosystem/stress matrix. The Subcommittee evaluated these rankings
with respect to whether or not the Subcommittee agreed with the
existing ranking, or if new information or understanding should
result in changes to the ranking. The Subcommittee also expanded
the ranking to include a category of low-impact effects (not
included in the original summary ranking).
4.3.2 Environmental Stress Rankings by Scale
The results of the reevaluation by the Subcommittee are
presented in Table VII (see page 21) . This matrix of rankings
separates the relative ecological importance of each environmental
stress by the scale of the stresses (biosphere/global; regional;
or ecosystem/local). The Subcommittee changed this stress matrix
only modestly compared to the initial summary ranking in the 1986
report. Specific changes to be noted include: 1) elevating the
issue of depletion of stratospheric ozone from CFCs and other
anthropogenic chemicals from the category of "unknown but
potentially very important" to the category of "high ecological
effects"; this elevation of concern is because of the acquisition
in the intervening three years of considerable information about
stratospheric ozone depletion in response to CFCs, including
evidence, from data from Antarctica, of exceptionally intense ozone
hole development in the austral springs of 1987 and 1989; 2)
addition of depletion of biotic resources to the "high" category
for regional scales because of an enhanced concern for large-scale
human activities such as tropical deforestation; 3) decreasing the
importance of oil and petroleum products at the ecosystem level
from "high" to "medium ecological importance" to reflect a
moderated concern about the ecological effects of oil inputs to
the environment; 4) addition of the category of "low ecological
importance", to which were added stresses of radionuclides, solid
wastes, and thermal pollution; this addition was done to indicate
20
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that these issues, while of limited concern ecologically, are
nevertheless not completely free of potential for adverse
ecological effects; 5) changing the issues of groundwater
contamination and chlorination products from the "unknown" category
to the "low ecological effects" category, based on better
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toxics to the global-scale "medium ecological importance" category.
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effect, but the potential exists for some types of inputs to have
very important effects; environmental stresses in this category
would require case-by-case evaluation to determine potential risks
to the environment.
4*3*3 Envir^fiifl^fltal stress Rankings by
The Subcommittee also considered the relative importance of
ecological effects of the environmental stresses, separated by
transport media (air, water, or terrestrial). That is, the
ecological risk ranking by spatial scale, discussed above, was next
examined with attention to the medium of transport of the stress
agent rather than by spatial scale. A new matrix of ecological
risk rankings (Table IX, see page 24) was prepared by the
Subcommittee, with the same elements as in the previous matrix.
This provides information about the relative ecological risks that
may be relevant to major divisions within EPA.
4.3.4 Ecological Recovery Times
The ranking of potential effects on ecosystems from the
ecological stresses included attention to the issue of recovery
22
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times. If a stress was considered to cause a very long-term effect
on an ecosystem, then it would be ranked higher than a stress to
which the ecosystem could recover more rapidly. The Subcommittee
decided that this information, if made more explicit, would be
useful to decision makers in evaluating policy options, especially
if combined with an estimate of the time scales that could be
involved in implementing options. Consequently, an ecological risk
ranking matrix was developed by the Subcommittee that indicates the
time for ecological recovery upon elimination of the stress (Table
X, see page 26). This primarily relates to intrinsic time scales
of ecological and biogeochemical systems. For, instance, a long
time for recovery from habitat alteration is indicated, as major
changes to habitat structures like soils or mature tree stands
require considerable time for the system to be reestablished at a
former state. Other time lags for restoration of the environment
relate more to the societal delays in implementing control options
as well as the time for the stress to be eliminated once the option
was implemented. For example, there may be a delay in recovery
from stratospheric ozone depletion effects, in part because the
residence times in the atmosphere of some CFCs may be a century or
longer, so that controls implemented immediately may not become
effective for decades, and in part because of delays in eliminating
CFC production and emissions in all countries around the world.
The combination of these factors (time lags intrinsic to stresses
involving physical systems, time lags intrinsic to ecological
responses to stress, and time lags for implementation of societal
controls) provides a rough estimate of the time scales that could
be involved in addressing and solving each particular ecological
stress.
4.4
The final ecological risk ranking prepared by the Subcommittee
is a synthesis of the above matrices. This ranking is provided
(Table VIII, see page 23) to give a single list of the
environmental stresses, numbered in order of decreasing potential
ecological risks. The synthesis rankings were derived
qualitatively using expert judgment rather than a numerical metric
based on the more detailed risk matrices discussed previously, as
the Subcommittee decided that any specific quantitative or semi-
quantitative methodology for combining risks assigned across scales
and media (e.g., adding the total number of cells with H
designations for each stress) would not be not defensible with
25
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Table X - Time for Ecological Recovery
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BOD
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Solid Wastes
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26
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present ecological risk assessment capabilities. However, the
synthesis ranking developed by the Subcommittee is not arbitrary,
but, rather, is based on criteria of the intensity, magnitude,
duration, and recovery prospects for each stress. The Subcommittee
feels strongly that a concerted and continuous effort by the Agency
to improve ecological risk assessment methodologies is warranted.
The synthesis ranking in Table VIII (see page 23) represents
the consensus of the Subcommittee and illustrates the increased
concern given by the Subcommittee to those issues of largest
potential spatial extent and longest potential recovery times.
Consequently, the environmental issues of global climate change,
habitat alteration, stratospheric ozone depletion, and biological
depletion are ranked very high, because of the pervasive extent of
these environmental stresses and the diversity of resultant impacts
on ecological systems at species, community, and process.levels.
It is notable that not until the middle grouping of environmental
stresses (2 and 3) do toxic chemical stresses become ranked with
respect to ecological risks. It should also be noted that for
rankings 3-6, more than one environmental stress is listed, as the
Subcommittee could not distinguish the ecological risks among the
stresses listed within a single number category. The last
category, high risks in some cases, is not ranked numerically, as
the potential exists in infrequent occasions for these stresses to
cause significant adverse ecological effects if improperly
regulated, but under other circumstances these stresses may cause
essentially no ecological effects.
Finally, the Subcommittee recognizes that the highest ranked
ecological risks do not reflect the present emphasis within EPA
and, indeed, include some aspects not presently within the
legislative mandate of the Agency (especially issues of habitat
alteration, for which EPA's role is mostly limited to wetlands
ecosystems) . Nevertheless, the Subcommittee believes the synthesis
ranking of ecological risks represents the ecological issues of
greatest potential danger to the environment of the United States
and of the Earth.
27
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5.0 WELFARE RISK XNXLYSIS
5.1 Background
The Subcommittee was charged with three specific tasks
regarding welfare risks: 1) evaluate Appendix IV of the Unfinished
Business Report (EPA, 1987c) entitled "Welfare Risk Work Group";
2) develop a welfare risk evaluation paradigm that is compatible
with the ecological risk evaluation system; and 3) combine the
ecological and welfare rankings into a combined priority array.
The Subcommittee is composed of environmental chemists and
ecologists. There are no economists on the Subcommittee, although
several were consulted. In the Subcommittees view, we cannot
engineer the time lags in the geochemical and ecological feed-back
loops. Economic analyses should always reflect a planning horizon
long enough to capture all effects of the issue under study. For
ecological issues, the time frame may have to extend for hundreds
of years and many generations of humans. If one wishes to combine
ecological and welfare impacts into an aggregate priority ranking
system, the methodology currently being utilized by the Agency to
quantify economic impacts roust; be modified to resolve this
discontinuity.
5.2 subco™1^ fc^ee Findings
The Subcommittee finds: a) that the EPA's welfare effects
analysis contained in Appendix IV, Welfare Risk Work Group of
Unfinished Business (EPA, 1987c) , was defined too narrowly within
the array of possible analytical alternatives and was too limited
to economics; b) that many of the assumptions of the economic
analyses used by EPA give insufficient attention to the current
state of scientific understanding; and c) that some of the details
of the economic analyses presented in the Unfinished Business
document were incomplete or inappropriate for addressing
env i r onmenta 1 pr ob 1 ems .
The Subcommittee began the welfare ranking evaluation by
redefining welfare effects to be all effects on humans and
societies, excluding human health effects, that may result from
28
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environmenta1 orob1ems. Thus, welfare risk was expanded to include
all aspects of the quality of human life as interacting with the
environment. These welfare effects may be indirect or direct.
Indirect welfare effects include those effects mediated by
ecological systems; i.e., effects on humans caused by changes to
the natural environment. These ecologically-mediated effects may
be further divided into impacts that involve irreversible
alterations to the environment, and therefore, fundamentally affect
resource sustainability (e.g., loss of biodiversity, depletion of
soils, elimination of habitats), and those alterations that are not
permanent but, nevertheless, have an impact on parts of the
environment that humans care about (e.g., reduction in fisheries,
eutrophication of lakes, reduced growth of commercial trees).
Direct welfare effects include those that have direct economic
importance (e.g., building damage from acid deposition) and those
that are non-economic (e.g., presence of excessive noise or odors,
reduced visibility, or other reductions in the quality of life).
The Subcommittee finds that the ranking for ecological risks
discussed previously and for welfare risks associated with
ecologically-mediated impacts are essentially the same. The
welfare risks associated with sustainable resources were evaluated
by the Subcommittee. The welfare risk ranking for direct economic
effects was not developed by the Subcommittee because of
insufficient data. The ability of science to contribute to the
ranking of non-economic effects is still developing and the
Subcommittee made an initial attempt at this ranking. Finally, the
Subcommittee developed an overall welfare risk ranking scheme
considering all four aspects of welfare risks.
5.2.1 Critique cf Appendix IV
The welfare effects analysis in Appendix IV (EPA, 1987c) was
based on a very small amount of information that was available to
the Agency. The analysts appeared to limit their concern to only
a few of the services produced by ecosystems, and ignored the more
complex and long-term interconnectedness of all living things on
earth. It is imperative that the Agency adopt a broader and more
inclusive view of ecosystem services and work to integrate this
view with economic analyses of environmental problems.
29
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5.2.2 attainability
It has long been recognized that short-term profit
maximization is a misguided objective. Economic analyses of
environmental issues must take a long-term view with the ultimate
goal of sustaining life supporting ecosystem functions. In the
long run, irreversible resource damage will undermine the
sustainability of the ecosystem and therefore, the quality of life
and the sustainability of human society itself.
The procedure of "...ranking future effects lower than
present, all else being held constant" (page 1-2, EPA, 1987c), is
not scientifically sound for ecological risks. There are several
compelling reasons why the economic discounting theory is
inappropriate for ecological issues. First, the concept of
discounting values of ecological resources at some fractional rate
per year is inconsistent with the "stewardship responsibilities"
(page 6-10, EPA, 1937c) emanating from the public trust doctrine
approach to most environmental legislation.
The concept and application of discounting needs further
examination. In particular, use of positive discount rates has
serious implications for intergenerational equity when applied to
long-time frame problems. Recognizing the inability of future
generations to "vote" in current capital markets and influence
interest rates, suggests that this is more than an economic
problem. We need to address the scientific and ethical issues
associated with "sustainable" social activity. For inter-
generational issues it may be appropriate to adopt a zero discount
rate.
Moreover, discounting future environmental problems greatly
devalues the importance of large-scale and long-term environmental
problems. Ecological systems have intrinsic time lags, such that
the adverse response from a stress is delayed to the future. This
is a basic characteristic of ecosystems that must be central to an
ecological risk assessment paradigm. For example, applying the
discounting theory to the issue of global climate change led the
EPA welfare report to treat this as a medium level problem because
the effects would not be felt until the middle of the next century.
Yet desirable and effective control and mitigation activities for
climate change effects must begin much sooner, because of the
inherent time lags in global responses. The costs of .mitigation
30
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are usually not constant over time, often increasing geometrically
because of the spatial dimensionality of the transport mechanisms.
Finally, the applications of discount rates to costs and
benefits associated with the environment incorrectly implies that
ecological services can be readily exchanged, both now and in the
future, as fundable commodities. Ecological resources provide
streams of benefits over time, and may therefore, be considered
environmental capital analogous to physical capital (e.g.,
equipment and technology) and human capital (e.g., knowledge and
skills). Environmental capital and the life-support services it
provides, are not, however, necessarily substitutable for other
forms of capital, and should not be discouraged as if they could
be bought or sold like machinery or housing.
5.2.3 Willingness to Pay
Most economic techniques employed in environmental
assessments, management, and policy formulation are based on the
assumption that individuals' tastes and preferences are the
appropriate basis of economic value. This premise allows
economists to use market prices, which reflect these preferences,
to estimate value. When services provided by ecosystems are not
traded on markets, economists use alternative criteria of value,
such as individuals' stated or implied willingness to pay for the
preservation of an ecosystem service (or willingness to accept
compensation of its loss).
When it is applied to the valuation of ecosystem services, the
assumption that value derives from individual preferences may be
inconsistent with fundamental ecological principles. Individuals
may enjoy the benefits of these services without any knowledge of
their existence, thus their preferences may imply values that do
not reflect the ecological importance of natural systems and the
services they provide to humans.
In addition, value criteria may be problematic. The use of
willingness to pay implies that values assigned by an individual
are constrained by his or her affluence. This may be inconsistent
with property rights vested in public trusteeship and with public
rights of access to unimpaired natural resources reflected in
Federal statutes: An Environmental Bill of Rights.
31
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The basic "services" provided by the ecosystem, including
supply of clean air and water, food chain maintenance, weather
control, provision of genetic diversity, etc., represent the
support system that all humans depend on. These resources need to
be protected from overexploitation. Yet in managing the ecosystem
as scarce resources, too much emphasis has been placed on
willingness-to-pay as inferred from individual actions or
statements. We need to recognize that the services provided by the
ecosystem are complex and long term. We need to develop more
complete descriptions of the ecology-economics interface. Not all
of these connections can be valued in dollar terms. Nevertheless,
information about these connections and services need to be
presented in a form appropriate for analysis by environmental
decision makers. These representations may not fit into the
traditional benefit-cost framework. Either that framework needs
to be expanded, or the information, should be presented in a manner
parallel to the benefit-cost framework.
Furthermore, the reality of "willingness to pay" is usually
not realized until the right to access is removed or seriously
threatened. This is true in general for scarce resources, but
presents a severe problem for environmental issues. By the point
in time at which this is realized, it may be too late or
excessively expensive to provide for the interconnectedness of the
environmental response. Consequently, societal demands for the
expenditure of funds to protect a threatened resource are much
greater than to maintain an unthreatened one.
5.2.4 Multiplier Concept
Economic impact analyses normally include secondary impacts
that affect the supporting economic infrastructure. When economic
analyses are utilized to justify economic development, multipliers
are standard procedures. If they are utilized on the development
side of the analysis, they must be utilized on the environmental
side as well. When the James River in Virginia was closed to
commercial and recreational fishing because of Kepone
contamination, the impacts included the losses to trucking
companies, fishing lure manufacturers, outboard motor repair shops,
etc. Thus, the real costs are far greater than the direct monetary
value of the fish harvest. If economic analyses are included in
welfare impact assessments, the real costs should be utilized to
illustrate the true benefits of environmental stewardship. Then,
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the benefits of major control and mitigation efforts would more
often exceed the costs of program implementation.
5.3 Welfare Riafc Paradigm
We propose an alternative welfare impact classification scheme
that is intellectually consistent with ecological functions and
time scales. As defined above, the specific welfare impacts fall
into four classes:
a) Ecological quality
b) Resource sustainability
c) Direct effects - economic
d) Direct effects - non-economic
These are discussed in further detail below (See also Table II,
page 3).
5.3.1 Ecological Quality
This class of effects are indirect impacts on humans that
result from a reduced quality of an environmental resource or
decreased human utility, but which do not permanently impair the
ecological structure and function of the resource. For example,
sublethal concentrations of PCBs in Great Lakes salmon do not
impair the growth, survivorship, or reproduction of the fish
stocks. Yet a risk assessment action level of 2 ppm prohibits the
sale of these fish in interstate commerce, and public concerns
about these contaminants in fish adversely affect the sport-fishing
industry. Similarly, the recent Exxon Valdez oil spill in Prince
William Sound, Alaska, produced a reduction in the breeding
populations of certain sea birds, sea otters, and intertidal
organisms. But this is expected to be a temporary loss in resource
that will not threaten the long-term integrity of the ecosystem.
Sublethal accumulations of toxic substances and intermittent
perturbations of the ecosystem structure and function characterize
this category.
5.3.2 Resource attainability
This category of welfare impacts involve irreversible losses
of ecosystem structure and functions. These can involve losses of
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critical habitats or species extinctions resulting from anthro-
pogenic activities. Wetlands destruction, soil erosion, conversion
of tropical rainforests to agriculture, and rising sea levels
illustrate these types of impacts. Sustained acute- or chronic-
exposure levels of toxic substances to critical classes of
organisms can also impair ecosystem functions. Persistent non-
point agricultural inputs of herbicides into surface waters could
inhibit primary productivity. Increased UV-B radiation from a
depleted stratospheric ozone layer could reduce algal productivity
in marine ecosystems.
5.3.3 Direct Effects - Economics
This category involves direct physical changes that cause
adverse economic impacts on humans (excluding human health
effects). The monetary damages to stone structures resulting from
acid rain, the loss in property value of houses with radon
contamination, and loss of surface water contaminated by industrial
effluents as an agricultural irrigation source are examples of
direct physical effects that have a clear economic value. These
are the effects that are usually included in environmental impact
analyses.
5.3.4 Direct Effects - Non-Economic
This category of welfare effects primarily involves social
nuisances. Odors, noise, and reduced visibility result from
sensory modalities that affect the perception of quality of the
environment but may or may not affect human health. The courts
have upheld social nuisance cases as legitimate examples of welfare
disbenefits. There are no generally accepted standards that define
an acceptable environmental quality, but liability is determined
on a case-by-case basis. Odors from animal feedlots, reduced
visibility in certain urban areas, and noise from truck traffic on
expressways are documented examples of these social perceptions.
5.4 Welfare Risk Rankings of the S^frcfrfflinit'tx
The rankings for welfare effects are based on differing data
bases. "Ecologically Mediated" welfare functions are based on
impacts on basic population and ecosystem processes. Therefore,
we determined that ecologically-mediated welfare risk rankings are
identical to those produced for the ecological effects, section.
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The welfare risk effects associated with ecological
sustainable issues involves impacts on the environment that are
irreversible or of long duration compared to human perspectives.
The Subcommittee considered time to recovery as an explicit
component of the rankings which are presented in Table XI (see page
36) .
The welfare function associated with the "Direct Effects -
Economic" class of responses can be directly calculated by monetary
damages. These data were not available to the Subcommittee, so no
rankings were possible for this welfare risk category.
The "Direct Effects - Non-Economic" welfare effects were
ranked by the Subcommittee using expert judgment, as no other
analytical methodology presently exists. We agreed that negative
impacts associated with sensory modalities (sound, sight, or smell)
should be included. We held diverse opinions on whether and how
human perceptions and feelings, such as fear, anxiety, and
unrealized expectations, should be included.
The integrated welfare rankings are contained in Table XI (see
page 36).
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Table XI - Integrated Welfare Rankings*
RANKING
WELFARE ISSUE
RECOVERY TIME
HIGH:
Global Climate
UV-B Ozone Depletion
Habitat Alteration
Biologic Endangered/Extinct
L
L
L
L
MEDIUM:
Acid Deposition
Airborne Toxics
Toxics in Surface Waters
Pesticides and Herbicides
Nutrients
Groundwater
M
M
M
M
M
LOW:
Acid Inputs to Surface Waters
BOD
Oil
Turbidity
Solid Waste (non-hazardous)
Radionuclides
Chlorination
Thermal Pollution
IN SOME
CASES,
HIGH RISK:
Deliberate Release of Genetic
Engineered Organisms
Introduced Species
a For Categories I, II, IV - Based on non-direct economic Issues
Recovery Time is given as long-term, or centuries (L); medium-term,
or decades (M); or short-term, or years (S).
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6.0 UPDATES ON RISK CATEGORIES
The Subcommittee reviewed the original EPA .list of
environmental problems (Table III, see page 10)) with the goal of
modifying the list if, in our view, the list was either incomplete
or duplicative from an ecological risk perspective. We made the
following modifications.
Problem areas 18 and 19, municipal and industrial non-
hazardous waste sites, were combined. Our review of the literature
led to the conclusion that the ecological impacts are not
significantly different.
The original EPA list included only one type of habitat
alteration, specifically areas 13 & 14, which dealt with discharges
(alteration) to aquatic habitats. The Subcommittee believes that
ecological impacts caused by alteration of terrestrial habitats are
certainly as significant as alteration of aquatic habitats and
should be considered in this report, even though regulation of
activities that cause such alteration is not presently an EPA
responsibility. The Subcommittee also considered habitat
disturbance to be a potentially significant ecological impact.
Even though not an irreversible physical alteration, habitat
disturbance by human activities (e.g., overflights, human and dog
access to beaches) can cause habitat abandonment or restricted use.
The Subcommittee added biological depletion to the list of
environmental problem areas. This category includes depletion of
natural populations because of over-harvesting as well as species
extinction. Introduction of species was also added to the list,
on the basis that exotic species may disrupt natural communities
and ecosystems.
The Subcommittee reviewed the Background Papers written by
EPA in 1987 and reevaluated them in light of more recent
information. These background papers were prepared by EPA in order
to provide additional insights concerning the environmental problem
areas. These were included in Appendix III of Unfinished Business
(EPA, 1987b). The following sections reflect the Subcommittee
discussion of these environmental problem areas. EPA summarized
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its ranking of environmental problems areas into six groups, with
Group 1 problems having the highest impact and Group 6 the lowest
impact. The EPA group ranking and our adjective ranking are
included in each section, generally at the end. Our rankings
follow the scheme given in Table VIII on page 23: (e.g., HHH > HH
> H > M > L) where HHH - Highest Risk; HH * Higher Risk; H » High
Risk; M = Medium Risk; and L - Low Risk.
6.1 Criteria and Toxic Air Pollutants
The ecological impacts of ozone and acid deposition are well
documented, and significant data bases on both the extent of ozone
levels and acid deposition now exist (HAS, 1989; NAPAP, 1989; EPA,
1988) . The overview of ozone and acid deposition provided in EPA
(1987b) is detailed and represents a reasonable summary of the
state of the art in 1986. Since then there have been a number of
studies (e.g., NAPAP, 1987) that have suggested that hydrogen
peroxide is also an oxidant that may lead to damage to trees.
Gaseous hydrogen peroxide is formed by photochemical reactions in
the atmosphere, and its chemistry is interlinked with that of
ozone. In addition, the photochemical reactions of non-methane
hydrocarbons (NMHC), nitrogen oxides, ozone, and hydrogen peroxide
are linked and affect the atmospheric concentrations of nitrogen
oxides, ozone, hydrogen peroxide, and the formation of airborne
strong acids. Ozone and hydrogen peroxide are important oxidants
that lead to the formation of nitric and sulfuric acids in rain and
cloud droplets from precursor nitrogen oxides and sulfur dioxide.
The direct ecological risks of all toxic air pollutants on
vegetative covers are not clearly established. However, there is
little doubt that various toxic air pollutants can accumulate in
plants and animals through the food chain (Travis and Arms, 1988).
Thus, effects on wildlife from bioaccumulation may be particularly
significant. It is possible that some toxic air pollutants may be
precursors to chemicals that may be toxic to plants. However, much
work is needed in this area in order to document exposures and
elucidate uptake mechanisms and associated ecological effects.
Although toxic air pollutants were ranked by EPA as Group 4,
some chlorinated hydrocarbons play an important role in atmospheric
photochemistry. Thus, while one can argue that the important
direct ecological stresses are ozone and acid rain, the factors
controlling the generation of those stresses are closely linked
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and inseparable. Nitrogen oxides are also a factor in acid rain
formation as well as visibility reduction. Since solar radiation
is an important factor that affects the generation of ozone and
hydrogen peroxide in the atmosphere, greenhouse gases and ozone can
affect solar radiation and in turn photochemical reactions. Thus,
problem areas 1,2,7, and 8 are intertwined.
Our ranking of this issue varies with the scale considered.
At ecosystem and regional levels, airborne toxics are high (HH)
risk, but at the biosphere level, that risk drops to medium (M).
Acid deposition is ranked at high (H) risk at both ecosystem and
regional levels.
6.2 Radiation from Sources other than Indoor Radon
This category includes environmental exposure to ionizing and
non-ionizing radiation (beyond natural radiation). Increased
radiation from stratospheric ozone depletion or medical exposures
is not included here.
There have not been important changes in either the
information base, risk assessment, or public perception concerning
radiation hazards to ecological systems since publication of the
Unfinished Business report. An extensive knowledge base,
conservative standards, and a highly-regulated industry have
reduced environmental risks. Nuclear industry practice is ALARA
(as low as reasonably achievable) for high-level wastes, oftentimes
well below regulatory guidelines.
The largest sources of radiation are natural cosmic and earth
background radiations, followed by routine medical and diagnostic
exposures to humans but not the environment. Anthropogenic
environmental exposures primarily result from residual weapons
testing fallout and industrial releases (including medical wastes).
Nuclear industry sources include uranium mill tailings, enrichment
and processing, spent fuel (fission products and transuranics),
low-level operations, and research by-products.
This problem area is characterized by a well-developed
historic (and aging) literature with a we11-developed risk
methodology, and extensive standards development and regulatory
oversight. Environmental transport mechanisms and pathways are
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known; biological/ecological effects are organismally based.
Current public concern is over environmental contamination and
perceived human health risks, with contaminant concern over
environmental movement and remediation. Ecological effects are
minimal under current practice. Regulatory philosophy holds that
protecting humans protects the environment, based on the general
greater radiosensitivity for humans than for other biota.
The Subcommittee estimates that ecological risks of these
sources are minor under current practices, with relatively low
uncertainty and number of unknowns. Thus, we disagree with
Unfinished Business statements of uncertainty for ionizing
radiations. Non-ionizing UV-B radiations are not addressed here
(see Stratospheric Ozone Depletion, Section 6.3), and non-ionizing
electromagnetic radiations have minimal (and localized, if any)
environmental effects.
The Subcommittee agrees that the low ecological risk ranking
is appropriate.
6.3 stratospheric Ozone Depletion
The issue of stratospheric ozone depletion (problem area 7)
was reasonably represented in the issue paper in the EPA report,
although a number of developments have taken place in the
intervening three years. It is still true that the main cause of
present and projected stratospheric ozone depletion is attributable
to production and release of chlorofluorocarbons (CFCs) (EPA and
UNEP, 1986; Hoffman, 1987). Worldwide emissions of CFCs remain
substantial, but there has been considerable progress in
establishing future limits internationally on CFC production,
beginning with the Montreal Protocols of 1987 and continuing to the
commitments made by Europe and the U.S. in 1989 to phase out
virtually all CFC production in the next few decades (Wigley,
1988). Consequently, projections of future CFC emissions would be
reduced from projections made three years ago (Lashof and Tirpak,
1989; Smith and Tirpak, 1989). On the other hand, not all nations
have made these phase-out commitments, and substantial inputs to
the atmosphere will continue for some time. Further, there is a
significant time-lag between cessation of emissions and reductions
in atmospheric, especially stratospheric, concentrations. Indeed,
residence times for CFCs are typically measured in decades or
longer, and stratospheric concentrations will continue to increase
40
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because of atmospheric dynamics even if all emissions were to cease
immediately (Lashof and Tirpak, 1989; Smith and Tirpak, 1989).
Over the past three years, there is also an improved
understanding of the atmospheric chemistry of CFOstratospheric
ozone interactions. For instance, the experience of the very large
stratospheric ozone depletion event over Antarctica in 1987 and
1989 has shown how CFCs, interacting with stratospheric ice
crystals and with sunlight as it first reaches the stratosphere in
the austral spring, can very rapidly deplete stratospheric ozone
(Stolarski, 1988; Rowland, 1988; Shea, 1989). This ozone-hole
phenomenon did not appear in the earlier models of atmospheric
chemistry, but has now been seen as well over the Arctic.
Furthermore, estimations of columnar ozone depletion over the last
15 years or so now exceed 5% for northern mid-latitudes, somewhat
larger than the original EPA issue paper suggested. Consequently,
there has been an increased sense of urgency added to this issue.
This urgency has been responsible for the progress noted above on
regulating global emissions of CFC's.
With respect to potential effects of enhanced UV-B radiation
on biological systems at the surface of Earth, there continues to
be a very inadequate data base to evaluate effects. We can state
with confidence that UV-B, in general, is biologically important,
as it is strongly absorbed by biologically critical compounds
(e.g., DNA), and, thus, like ionizing radiation, has the generic
potential for deleterious effects on biota (Worrest, 1985).
Experimental data on UV-B effects show sensitivity for many marine
planktonic and larval species, and there is a general consensus
that enhanced UV-B could lead to adverse consequences on marine and
coastal ecosystems (Worrest, 1985; Hoffman, 1987). However,
experimental data on UV-B effects on most terrestrial plants are
lacking; for example, how enhanced UV-B would affect the trees in
a tropical rain forest is essentially unknown. For crop plants,
about 200 cultivars have been tested, for which about one-third are
insensitive, and another third very sensitive, but experiments have
not been conducted for many important crops (e.g., work has been
done on only a very limited number of cultivars of rice). Thus,
assessing the potential biological consequences of increased UV-B
is difficult at present, although a research effort to obtain UV-
B dose response data for plants of ecological or agricultural
importance would reduce those uncertainties readily and with
limited expense.
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Secondary and indirect effects of increased UV-B are poorly
known? examples of potential indirect effects include increased
susceptibility to disease or pests by terrestrial plants.
Similarly, little is known about interactions of enhanced UV-B with
other concurrent stresses, such as water stress from climate
change. Again, an experimental program could reduce these
uncertainties considerably.
The EPA ecological workgroup ranked stratospheric ozone
depletion as being of very high concern. We concur with this
ranking because: 1) the mechanisms for adverse biological effects
are common across biota; 2) the stress will be globally distributed
and, therefore, something to which virtually all ecosystems and
agricultural systems will be exposed; 3) the time-frames for the
stress on the environment are long (decades to centuries); 4) it
is not possible to mitigate against the ecological effects of
increased UV-B; and 5) it may be difficult to adapt agricultural
systems to enhanced UV-B at the same time adjustments are to be
made for climate change stresses.
6.4 Global Climate Change
The issue of concern here relates to anthropogenic emissions
to the atmosphere of gases that have radiatively important
properties (i.e., they absorb light at wavelengths that control the
Earth's thermal balance). Continuous rate of these emissions are
expected to lead to a greenhouse response, with projected global
climate change to occur over the next few decades at magnitudes
previously seen only over geological time frames (Bolin et al.,
1986) . The EPA issue "CO2 and global warming" (problem area 8) is
more properly labeled "issues of global climate change", because
C02 is only about half of the present contributor to equilibrium
temperature changes among anthropogenic emissions, and because the
stresses on the environment of ecological and agricultural
significance are not limited to warming (e.g., changes in
precipitation often may be more important than changes in
temperature).
Anthropogenic sources of radiatively important gases include
C02, primarily from combustion of fossil fuels, but also from
deforestation and cement production; CH4, primarily from
agricultural production, especially from livestock and in rice
paddies; N20, primarily from agricultural releases, especially from
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bacterial action on fertilizers; and CFCs, the sane compounds of
central concern to stratospheric ozone depletion (Keeling et al.,
1982; Bolin et al., 1986; Bolle et al., 1986; Lashof and Tirpak,
1989; Smith and Tirpak, 1989). Insofar as CFC emissions are
limited for ozone-depletion reasons, this will make a significant
difference to the eventual magnitudes and rates of climate change
over the next several decades (Wigley, 1988). On the other hand,
even with complete elimination of CFCs, C02 production globally
will continue to increase, with the greatest growth in emissions
attributable to developing countries (Lashof and Tirpak, 1989).
Present best estimates of globally averaged temperature
increases at equilibrium are between 1.5 and 4.5'C for an
effectively doubled CO2 atmosphere (i.e., with total radiatively
important gas concentrations increased to the level equivalent to
doubling of C02 if that were the only radiatively important gas)
(NAS (1979, 1983, 1987); Smith and Tirpak (1989); Bolin et al.
(1986); MacCracken and Luther (1985)). While these numbers are
useful for comparisons to paleoecological records or to compare the
relative effects of alternate strategies for controlling greenhouse
effects, a globally- and annually-averaged temperature increase
does not capture the important stresses from an ecological or
agricultural effects perspective. Issues of spatial and temporal
scale are critical, as are issues of changes in the frequency,
intensity, or duration of extreme events (as opposed simply to
changes in averages). That is, what will have most importance to
causing biological effects will be climatic extremes, and a
shifting climate, even with unchanged relative variances, will
likely lead to an increase in extreme events. Moreover, whereas
the physical stresses of global climate change will be distributed
globally (albeit not uniformly), the biological and human effects
will occur at local and regional scales and must be evaluated at
that scale (Harwell et al., 1985a).
The present scientific consensus emerging is that global
climate change will occur in the next few decades; there is less
agreement that climate change has already occurred (data support
temperature increases in the last few decades for the entire
planet, but not for the United States, for example) (Hansen and
Lebedeff, 1988; Hanson et al., 1989; Jones and Parker, 1990).
Further, even if climate change is accepted as occurring at
present, there is no consensus that such change can be causally
attributable to anthropogenic emissions or other human activities
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(e.g., Kerr, 1989). Nevertheless, that climate change will occur
is widely, although not universally supported in the scientific
community. How much climate will change, in what regions, and at
what rate, are issues of much less agreement, and considerable
uncertainties remain in projections. How general circulation
models treat cloud formation, atmospheric-ocean interactions, and
biological feedbacks (e.g., changes in rates of biogenic gas
production, changes in albedo, and rates of evapotranspiration),
are issues in need of considerable scientific research (e.g.,
Robock, 1983; Dickinson, 1986; Hansen et al., 1984; Brpecker,
1987) .
On the biological effects side, it is clear that temperature
is not the only, or often even the most important, stress
associated with global climate change. Precipitation changes, in
intensity, location, and timing, are much more likely to affect,
for example, agricultural production than are increases in growing
season temperatures for many regions of the world (Parry et al.,
1988a,b). Changing water relations, and the effects of climate
change on hydrologic cycles, could have a major impact on regional
water balances of the continents. Other issues of ecological
importance include sea-level rise, presently projected to be about
0.3 - 1.0 meter by the middle of the next century, from thermal
expansion of the oceans (Smith and Tirpak, 1989; Lashof and Tirpak,
1989). Sea-level rise would have major consequences on coastal
ecosystems, including wetlands, estuaries, and spawning grounds for
fisheries. Other physical stresses associated with global climate
change may include changes in the frequency and intensity of
storms, shifts in ocean currents and upwelling areas, and shifts
in the intra-tropical convergence zone and in patterns of monsoonal
development, among others.
Estimating biological effects can be done by using a range of
analytical methodologies to relate changes in the physical
environment with crop productivity as well as ecosystem
distribution. Available methods include historical analogs (e.g.,
Stommel and Stommel, 1979); statistical models (e.g., Uchijima,
1981); physiological experiments (e.g., Uchijima, 1982); life zone
classifications (e.g., Emanuel et al., 1985); paleoecological
records (e.g., Davis and Botkin, 1985); simulation models (e.g.,
Harwell et al., 1985b), and expert judgment. For example,
physiologically based crop simulation models can be used to
estimate how changes in climate will affect phenology and yield of
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particular crops at specific locations. Equilibrium ecological
effects can be estimated from paleoecological analogs and by
examining bioclimatic life zone shifts, with associated changes in
the distributions of biomes. But much research on effects remains
to be done, including some experimental (e.g., how crop yields or
ecosystem productivity would change in combinations of altered
climate and enriched C02 - see review in Idso, 1989) , and other
more theoretical research (e.g., model development and sensitivity
analyses).
Effects of global climate change are only broadly estimated
at present. This is an area of particular importance and relevance
to EPA. Indeed, in the growing national program on global climate
change, effects issues appear to be given insufficient attention,
yet it is the effects on ecological, agricultural, and human
systems that are of real concern and that must be understood in
order for policy options to be properly evaluated. The issue of
global climate change was given the highest ranking by the EPA
ecological workgroup. We concur with that ranking because: 1) the
potential for biological effects is so large and ubiquitous since
the physical climate has such an important control on ecological
systems as well as crop productivity; 2) the time-lags built into
atmospheric, oceanic, and biospheric systems are so long that
actions today will have consequences for decades to come; 3) it is
not possible to mitigate against climate change occurring from
gases that have already been emitted to the atmosphere; 4) it is
possible to mitigate against the effects of climate change,
especially for agricultural and societal systems, but a much better
understanding of the spatial and temporal distribution of climate
change and a much better understanding of the environmental and
human effects of climate change are essential before proper
mitigation can be designed; and 5) with appropriate attention by
EPA to biological effects issues, a critically important but
otherwise insufficiently addressed facet of the global change issue
can be significantly advanced.
6.5 Direct and Indirect Point Source Discharges to Surface Waters
Direct and indirect point source discharges commonly refer to
the discharge of pollutants to surface waters from publicly-owned
waste treatment facilities (POTW) (15,000) and industrial outfalls
(24,000) (EPA, 1987b). These discharges are regulated by EPA
through a permit system (National Pollutant Discharge Elimination
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System, NPDES) that allows release of both conventional and toxic
pollutants at specified levels. Dischargers are clustered in the
eastern and midwest regions, where human and industrial activities
dependent on aquatic resources are most dense (EPA, 1987b). Many
industrial operations contribute to the load reaching municipal
waste treatment facilities, and therefore, are indirect dischargers
to aquatic systems. Waste treatment facilities discharge mainly
to rivers (except in coastal zones) experiencing seasonal
fluctuations in flow. Low flow in receiving water (e.g., late
summer; drought periods) often leads to high concentrations in
water and potentially deleterious impacts on the aquatic ecosystem.
Conventional pollutants of major concern are BOD (biochemical
oxygen demand), suspended solids (SS), and nutrients (P in
freshwaters; N in estuarine waters). The latter lead to excessive
growth of undesirable algae and aquatic plants. Toxic pollutants
include trace metals (e.g., Cu, Cd, Cr, Hg) and organic compounds
(PCBs, phenols, etc.). Most current requirements for controlling
discharges are technology-based rather than water quality-based,
although there is a trend toward more water-quality-based
regulations.
Although strategies to limit discharge of conventional
pollutants are improving, removal of toxic chemicals requires a
fully-implemented industrial pre-treatment program. Point-source
discharges also include combined sewer overflows. Many of the
industrialized cities of the eastern and central states are moving
to separate municipal waste and urban runoff.
We recommend that a wider variety of chemicals than presently
are regulated be monitored in both discharges and receiving waters.
In addition, a clear understanding of the ecological impact of
municipal and industrial discharges is badly needed. EPA ranked
this issue in Group 3.
6.6 Non-Point Source Discharges to Surface Waters Plus In-Place
Toxics in Sediments
The EPA document (EPA, 1987b) states that "the major
ecological risk from non-point sources is ...agri-
cultural. ..erosion". Non-point source pollutant inputs to surface
waters, however, also include erosion from other sources (e.g.,
silviculture, mining), groundwater transport, atmospheric
deposition, urban runoff, and resuspension/recycling of in-place
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pollutants. The best known of these inputs is erosion of surface
soils resulting from land disturbance by agriculture, development,
and natural processes (e.g., hurricanes; flooding). Groundwater
contaminated by pollution activities on land may contribute to the
pollutant load of nearby surface waters. In Switzerland and
Germany, there are many examples of surface waters contaminating
local groundwaters through bank infiltration. The problem of
atmospheric deposition of toxic elements and chemicals to aquatic
ecosystems has been emphasized by the role the atmospheric pathway
plays in the Great Lakes. In general, the processes leading to
removal of contaminants from the atmosphere and the air-water
exchange of volatile species are not well understood (Eisenreich
et al., 1981; Strachan and Eisenreich, 1988). The importance of
atmospheric deposition to pollution inputs in other aquatic systems
such as Chesapeake Bay needs to be studied.
The most severe problems associated with in-place pollutants
occur in bay and harbors that have received extensive inputs of
particle-reactive organic compounds and toxic metals. These
pollutants continue to recycle in the ecosystem by natural (e.g.,
bioturbation; winds) and anthropogenic processes (e.g., dredging;
ship traffic; continued inputs) for decades and longer. Examples
of areas where in-place pollutants are a particular problem are New
Bedford Harbor, Waukegon Harbor, Fox River/Green Bay, Toronto
Harbor, Los Angeles Bight, and Long Island Sound. However, rivers,
lakes, estuaries, and coastal waters where sediment deposition
accumulates, and near urban/industrial centers, have bottom
sediments with measurable quantities of toxic metals and organic
compounds. Even at low concentrations, some chemicals may move
into benthic organisms and concentrate in the food chain. Although
most interest has been in protecting health of humans consuming
fish from contaminated areas, more attention must be placed on the
interaction of benthic organisms with in-place pollutants.
Control of non-point sources of pollutant inputs to surface
waters may be difficult and expensive. In the case of atmospheric
transport and deposition of pollutants, sources are often diffuse,
distant, and uncontrolled or unidentified. The Subcommittee
expands the scope of concern beyond the Unfinished Business
document to include the above and agrees with a Group 3 or high
ranking. For the special case of pollutant emission to the
atmosphere, and then transport over long distances before
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deposition, the Subcommittee ranks this problem high on a regional
scale, and medium on a global scale.
6.7 77in^pinate
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The Subcommittee agrees with the basic risk ranking for sludge
of low to medium, depending on the area being exposed. Localized
impact can be much greater (e.g., the 12 Mile Dump Site), but
relative to such issues as global climate change, it does not
warrant a high ranking.
6.8 Physical Alteration of Aquatic Habitats
Although current environmental laws require mitigation and
enforcement to compensate for wetland destruction for some federal
programs, a majority of the habitat loss in the United States
results from currently unregulated activities or processes.
Channelization and drainage for agricultural production,
impoundments of total wetlands for private use, erosion-caused
sedimentation of stream habitats, destruction of riparian
communities by animal grazing, and bulkheading and filling for
shoreline development are all prime examples of poorly regulated
activities leading to wetland destruction.
Many of these activities are associated with agricultural
practices throughout the country or with coastal developments
associated with urban expansion. Activities on public lands should
be required to abide by sound environmental practices, independent
of which agency has the administrative responsibility.
Although the impacts of any single activity are local, the
activities are common throughout the country and the impacts are
cumulative. The aggregate impacts amount to an unacceptable loss
of ecological resources, and the irreversible nature of the impacts
on biological diversity and ecological productivity requires a
major programmatic emphasis across all governmental organizations.
Several specific activities warrant special attention.
Draining and filling of isolated freshwater wetlands by agriculture
should demand the same regulations as those required of the Federal
Department of Transportation. Public construction grants that
support infrastructure development (e.g., roads, sewers, water
supplies, and power networks) should not provide support in coastal
areas characterized by tidal marshes and coastal estuaries. Local
zoning ordinances cannot be expected to protect priority aquatic
habitats once the infrastructure is constructed. Commercial
fisheries operations using throw nets or trawls physically impact
benthic habitats. These activities should be restricted from
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critical areas. Animal grazing needs to be regulated on riverine
communities along rivers, streams, and pocket wetlands.
A viable aquatic habitat includes a diverse and productive
terrestrial community adjacent to the land-water boundary.
Sedimentation control is likewise required to protect riverine
habitats. EPA should adopt and enforce a watershed management
paradigm for aquatic habitat protection. This regulatory approach
should be implemented by all federal organizations that have
managerial responsibilities for public lands.
The Unfinished Business report ranks this irreversible trend
in habitat destruction in Group 2. For the above reasons, we
concur with this emphasis on aquatic habitat loss.
6.9 Active Hazardous Waste Sites
The Unfinished Business report ranks active hazardous waste
sites in Category 6 (low risk). The Subcommittee challenges this
conclusion based on future trends and not on current data. This
category includes the operations of incinerators, land disposal
facilities, recycling units, and other chemical/physical/biological
treatment technologies.
The locations of these operations are usually a function of
source location and can be found in a wide array of environmental
settings. These facilities require the transportation, storage,
transformation, and disposal of a great variety of organic and
inorganic toxic substances and pathogens. These materials come
from chemical industries, defense industries, municipalities,
medical industries, and agribusiness.
The assumptions in the Unfinished Business Report are that
active hazardous waste sites are currently regulated by RCRA/CERCLA
and, therefore, are or will be well designed, constructed, and
managed. Environmental releases of vapors to the atmosphere and
leachates to the surface and groundwaters are expected to be low,
and the effects limited to local impacts. These are the same
assumptions that were made for the last generation of permitted
hazardous waste sites with obvious shortcomings. These sites were
permitted by State and Federal agencies with the full expectation
that the technologies would be adequate to protect the environment.
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Active hazardous waste sites are not environmentally benign,
and there still exists a number of important scientific issues
that are not well understood and documented that produce
significant uncertainties about many of these technologies. The
perception that leachates only migrate slowly through the saturated
zone of the soil has been challenged by recent research at the Oak
Ridge National Laboratory. Episodic events of heavy rains produce
rapid horizontal migration of toxicants through the unsaturated
zone, resulting in increased loadings to surface wetlands. Clay
liners and clay caps on landfills with backup leachate collection
systems are designed to prevent and remove leachates. It took two
decades for the failures of our last generation of landfills to
present themselves. Few, if any, of the new generation of
engineered landfills have been operating long enough to document
the real performance with field data. Usually the weakest link is
the management after a routine pattern of operation has developed.
The controversies surrounding incinerators are far from
resolved. The chemistry of combustion associated with large-scale
incinerators receiving a feedstock flow of variable quality is not
well known. It was only in the last decade that we associated the
formation of chlorinated dioxins with thermal treatment. Many of
the residuals from incinerators are discharged directly into the
atmosphere, which increases the spatial scale of dispersion.
The EPA Unfinished Business Report characterizes the impacts
as localized and potentially reversible over a 10-year period.
This conclusion is not supportable. The wide distribution of sites
produce a cumulative pattern whose impacts are not local. The
reversibility of impacts from resilient toxic compounds in soils
and groundwater requires far more than 10 years.
We recommend that this category be given the same rank (i.e.
Group 5) as the other toxic waste stream categories instead of the
Group 6 ranking given to it in Unfinished Business.
6.10 Inactive Hazardous Waste sites
Past disposal practices for hazardous waste often met legal
requirements at the time, but the resulting contaminated soils and
groundwater and air emissions have become a major concern for the
present and future. The primary focus of this concern is on the
substances released from these sites that could impact humans via
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surface water, groundwater, or air. Less attention has been paid
to the ecological impacts of such releases.
At the time Unfinished Business was written (EPA, 1987a,b,c),
there were 888 sites on the National Priority List (NPL). Ground-
water contamination was found at approximately 75% of those sites,
surface water contamination at 45%. A survey of 540 sites listed
the 15 most frequently observed chemicals as TCE, lead, toluene,
chromium and compounds, benzene, chloroform, PCBs, tetrachlor-
ethane, trichloroethane, zinc and compounds, arsenic, cadmium,
phenol, ethylbenzene, and xylene (EPA, 1987a). There are now 1,175
NPL sites, and EPA estimates that there will be more than 2,100 by
the year 2000 (Lucero and Moertl, 1989).
Hazardous wastes account for approximately 20% of all
industrial wastes and are produced by virtually every type of
manufacturer (Paisecki and Davis, 1987). Further, chemicals in the
waste do not remain fixed where they are deposited. Some wastes
have appreciable vapor pressure or are gaseous at ambient
temperatures (e.g., vinyl chloride trapped in PVC processes) and
will diffuse through fill, appearing in ambient air at the site.
Chemicals can often leach into underlying aquifers and be
transported via groundwater flow. Contaminated groundwater may
eventually feed surface waters, contaminating streams and lakes or,
possibly, nearshore marine habitats (Peirce and Vesilind, 1981).
Nearly all chemicals found at inactive waste sites are toxic
and known to have chronic or acute effects on organisms. However,
there are limited data on the concentration of the substances and
the exposures that animals and plants experience. Although there
is little information on ecological effects at Superfund sites, a
survey estimated that 6% of the NPL sites are likely to have
significant damage to natural resources such that natural resource
damage awards are likely to be sought under CERCLA (EPA, 1987a,b).
There could be significant ecological impacts if toxic and
persistent chemicals (e.g., PCBs) contaminate sediments in aquatic
habitats (e.g., harbors, wetlands). This scenario sets the stage
for long-term exposure of organisms, particularly the benthos.
Hazardous waste generators are facing a shortage of existing
landfill capacity, which has a projected lifespan of 10 to 15 years
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unless something is done to decrease the amount of waste (Nelson-
Horchler, 1988).
EPA placed this category in Group 5. The Subcommittee
currently ranks the ecological risk from inactive hazardous waste
sites as medium (M) because ecological impacts tend to be localized
in the immediate vicinity of the site. However, the number of
known sites and their potential to release toxic and persistent
compounds into the environment are of sufficient concern to warrant
close and continuing attention to this problem from an ecological
as well as human health perspective.
6.11 Municipal and Industrial Non-Hazardous Waste Sites
Some non-hazardous waste landfills contain only municipal or
industrial wastes, and some contain wastes contributed by both
groups, in varying amounts. The Subcommittee believes that, from
an ecological standpoint, these waste sites should be considered
together. Non-hazardous waste landfills will eventually generate
leachate and gaseous releases (Charnley et al., 1988; Webster,
1988). Releases from these landfills may be to the atmosphere,
soils, groundwater, and surface water. Potential effects are to
biota as well as human health.
Inputs to municipal waste sites include paper, yard wastes,
food, plastics, metals, glass, textiles, wood, and a miscellaneous
category that can include chlorinated organics (e.g., from cleaning
fluids) and aromatics (e.g., from paints and household products).
(Webster, 1988; Franklin Associates, 1988). Releases from these
landfills may vary, but Wood and Porter (1986) identified 77
chemicals known to be released from municipal waste landfills,
including methane, benzene, toluene, vinyl chloride, trichloro-
ethylene, and methylethyIketone.
Industrial non-hazardous waste sites usually contain
substances specific to a particular operation and may be located
on an industrial facility site or at a site that combines wastes
from a number of different industrial contributors. Examples
include wastes from building demolition, phosphate fertilizer
manufacturing, or oil-drilling operations. Landfarming has been
extensively used for some of these wastes (Huddleston et al.,
1982).
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It is not possible to predict how long it will take for a
particular landfill to stabilize to the point where it will no
longer produce and release products. However, Charnley et al.
(1988) cite a report by Pohland et al. (1983) which describes 5
stages in the life of a landfill. Each stage yields characteristic
compounds that are released to the air or to leachate.
Stage 1. Initial Adjustment - This stage occurs after the
refuse is placed in the landfill until it has absorbed moisture.
Little, if any leachate is formed during this stage, stegen et al.
(1987) estimated that this stage takes 6-18 months.
Stage 2. Transition - During this stage the refuse has
absorbed moisture and begins to form leachate. Microbial
degradation changes from aerobic to anaerobic.
Stage 3. Acid Formation - Anaerobic degradation continues and
volatile organic acids reach their highest concentration. The pH
declines rapidly.
Stage 4. Methane Fermentation - The intermediate products
formed in stage 3 are converted to methane and CO2. The pH of the
refuse is buffered by a bicarbonate system. The amount of leachate
decreases, but the amount of gas produced increases.
Stage 5. Final Maturation - Microbial action is limited due
to decreased availability of nutrients. Gas production ceases and
oxygen and oxidized species slowly reappear. Compounds resistant
to microbial digestion are converted to humic-like substances
capable of complexing with and mobilizing heavy metals. When the
rate of change within the waste becomes negligible, the landfill
is considered stabilized.
Releases from landfills that contain only municipal wastes and
those that contain both municipal and industrial non-hazardous
waste are indistinguishable, unless the site is dominated by a
particular industrial waste. For most sites, the quantities of
lignin-containing wastes, chlorinated hydrocarbons and aromatics
from municipal wastes are so large that chemicals derived from the
industrial wastes cannot be detected against this background
(Webster, 1988).
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The Subcommittee agrees with ranking the ecological risks from
non-hazardous waste sites as Medium (M) (or Group 5) on the basis
that the impacts are largely local. Releases are generally of low
concentration. The long-term nature of the releases and the number
of and distribution of sites, however, warrant continuing
attention to this issue.
6.12 Alteration and Disturbance of Terrestrial Hftfritfrt*
This topic was not addressed or ranked in the EPA Unfinished
Business report. The Subcommittee feels that it is an important,
ubiquitous ecological problem contributing toward loss of
biological diversity and therefore should be considered.
As human populations and their support systems expand, natural
habitats and the populations they-support are disturbed, altered,
or destroyed. There is a consensus among ecologists that species
extinctions are now occurring at unprecedented rates (Wilson, 1988;
Wright, 1990). The major cause of species loss is destruction of
natural habitats. The most significant and publicized losses
currently are the results of conversion of tropical forests to
agriculture in Latin America and Southeast Asia. However, natural
habitat losses are occurring everywhere, even in industrialized
countries with strict environmental regulation. For example, oak
woodlands and chaparral are rapidly being converted to housing
tracts and avocado orchards in southern California mountains. Most
native prairies and grasslands in the United States have already
been converted to agriculture.
Habitats can be altered, converted, or disturbed with varying
ecological impacts. Conversion of a habitat results in irreversible
loss; e.g., a forest is converted to a housing tract, and survival
of native plant and animal populations is no longer possible.
Partial alteration of a habitat (e.g., road construction) can
result in shifts in diversity and abundance of natural populations,
but may allow survival of the ecosystems. Habitat disturbance may
be caused by human activities near natural populations (e.g.,
aircraft overflights) and result in abandonment or decreased use
of the habitat. For example, allowing public access to a
previously isolated beach causes harbor seals using that beach as
a rest area to abandon it (Bartholomew, 1967; Woodhouse, 1975).
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Although the impacts of any single activity are local, the
cumulative result is major, and for the most part, results in
irreversible loss of natural ecosystems, including species
extinctions.
Every effort should be made to preserve native ecosystems in
parks, reserves, and sanctuaries, but this action alone will not
significantly reduce the rate of losses. An equal effort is needed
to minimize the impacts of development so that, to the extent
possible and practical, natural populations can survive. For
example, leaving corridors of natural habitat through developed
areas allows more native populations to survive (Millar and Ford,
1988) . More attention should also be paid to restoration and
enhancement of natural habitats (Jordan et al., 1988), including
research programs to build the science base upon which these
activities rely.
Some types of development are more compatible with natural
systems than others. Such projects maintain a large portion of the
property in open space, permitting the survival of natural
populations. Examples of these are military bases, oil fields, and
low-density housing. These projects should be planned with the
goal of maximizing the survival of natural populations while
accomplishing the goals of the project.
Finally, sound environmental planning and management to
minimize the ecological impacts of development should be a part of
every approved project. More research is needed to develop cost-
effective environmental planning and management methods. Lengthy,
detailed ecological studies are not a realistic expectation for
most development projects, yet accurate, reliable data are needed
for use in planning.
The Subcommittee sees habitat alteration and loss of
biological diversity as a local, regional, and global problem of
increasing importance with high cumulative impacts and, therefore,
high ecological risks.
6.13 Accidental Releases of Toxics
Over 2,000 accidental releases of toxicants occur annually
involving some 40 million pounds of the total. Only 2.4% of the
events release 90% of the total amounts of toxicants. Most of
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these come from fixed facilities and occur on land. Most states
enforce emergency containment and cleanup procedures at large
facilities.
The EPA Unfinished Business Report downgraded the importance
of persistent toxicants (PCBs, Kepone, dioxins, etc.) since they
do not constitute a large percentage of the total spills. A
majority of the materials accidentally released are nonpersistent
organics like TCE and DCE. Given the above, the low risk ranking
is appropriate.
6.14 Oil Spills
On average about 11 million gallons of oil are spilled each
year; 60% of this amount is spilled into marine environments and
40% in inland environments. Approximately 40% of all oil spilled
is crude oil, 30% diesel and other fuel oils, and the remaining 30%
other products (EPA, 1987).
Most experimental and monitoring work has been done on crude
oil spills in the marine environment. A large body of literature
has been developed since the Torrey Canyon spill in 1967 and the
Santa Barbara spill in 1969 (e.g., API, EPA, USCG Oil Spill
Conference Proceedings 1969-1989). Large oil spills, though
infrequent, can have significant ecological impacts. Spills of
crude oil in the' marine environment are primarily surface events
rather than water-column events. The most severe (i.e.,
population-level) impacts are on organisms that interact with the
water surface and oiled shorelines. Water column and benthic
populations are affected far less, usually not at the population
level. Impacts of most oil spills, even large ones are in the
"years" category of duration (NRC, 1985) . This is likely to be the
case for most populations affected by the large 1989 Exxon Valdez
spill in Prince William Sound, Alaska, as well (Baker et al.,
1990). The exceptions to this are spills that enter low-energy
habitats where oil penetrates the sediments and may remain for long
periods. For example, oil spills kill adult mangrove trees. It
may take 20 years to replace such trees.
Spill-response techniques can greatly influence the ecological
impacts of the spill. In spill situations there is often a
conflict between the goal of removing visible oil from the
environment and that of minimizing the ecological impacts of the
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spill. There are many examples where harsh and damaging "cleanup"
methods have actually increased the overall impacts of the spill
and prolonged recovery (e.g., using heavy equipment in marshes and
steam cleaning to remove oil from rocks). We recommend that the
overall goal of spill responses should be to minimize the
ecological impacts of spills and that response methods be chosen
to accomplish this goal and, preferably, planned in advance. The
importance of site-specific contingency planning and of streamlined
decision-making during a spill event cannot be overemphasized
(Lindstedt-Siva, 1984).
More research is needed on the fate, effects, and response
methods for spills of crude oil and products into inland waterways.
For some of these products there is significant potential for
water-column or benthic, as well as surface, effects. In addition,
some of the response methods appropriate for spills in marine
environments are not appropriate for inland waterways.
The Subcommittee agrees with the overall ranking of Group 5
or Medium (M) for the impacts of accidental oil spills. The
rationale is that spilled oil degrades, loses toxicity, and
generally does not persist in a biologically active state in the
environment for many years as, for example, chlorinated
hydrocarbons do. The most serious, longer-term impacts from
accidental oil spills have been from spills of refined products
(more toxic than crude oils) into low-energy, confined bodies of
water where the oil has become incorporated into sediments.
6«15 Underground Storage Tanks
It has been estimated that from 10% to 25% of the underground
storage tanks (USTs) in use currently are leaking. This may
engender ecological risks not apparent to similar lack of
containment for the same materials stored above ground. At first
glance, the major potential for UST contamination of the
environment would be that associated with contaminated groundwater,
particularly in those rural areas where potable water is derived
from shallow wells. However, over a long time period such
contamination of groundwater with petroleum products may be
significant to some surface waters derived from contaminated
aquifers where the ecological effects may be more apparent. In
cases of known leaking USTs, removal is required, with
decontamination of the affected environs at considerable expense
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to the owner of the site. In cases where a family business is the
responsible party, the costs of such remediation may result in
cessation of business and possible inadequate financial resources
to implement remediation, leaving the problem unsolved. This
problem, then, has serious economic consequences as well as the
potential for environmental perturbations. The problem of leaking
USTs is widespread and perhaps cumulative over the years,
reflecting lack of comprehension of the problem and its potential
for harm.
The prevalence of the problem and the impact on small business
and landowners and the potential for cumulative effects suggest
that several research areas need to be developed to ameliorate this
widespread problem.
Additional research should, be implemented towards the
development of devices and procedures for early detection of
leaking USTs, which will enable periodic inspection and
certification of such tanks. Such detection ideally should be
low-cost and involve minimal perturbation of the environs of the
tank and the business activity at the site. Reliable devices of
high sensitivity that can be operated by individuals with minimal
technical skills should be developed as an analog of more
sophisticated technology currently available.
Research should be implemented towards the remediation of
contaminated soils near a leaking UST. Such research might be
focused on in-situ remediation, remediation in close proximity to
the contamination site, or utilizing slurry reactors in a closed
system. For these alternatives, developments in biotechnology
currently available for bioremediation should be considered and
evaluated to minimize the cost of remediation if prescribed.
In general, the ecological risk from leaking USTs is low, but
the risk to humans may be high in cases where potable water
supplies are derived from shallow aquifers down gradient from the
storage tank. We agree with the ranking of Group 6.
6*16 Groundvater
Groundwater contamination is perceived by the public to be a
major class of environmental insults. The EPA Unfinished Business
report includes statements like "200 contaminants have been
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identified" and "millions of occurrences are found nationwide."
The medium rank assigned in the EPA report was based on the
assumption that ecological impacts can only occur when groundwater
discharges to the surface. The filtering properties of soil and
the dilution by surface waters will reduce the risk by reducing
exposure concentrations.
The filtering properties of soil constitute a short-term
buffer. Eutrophication of freshwater lakes from old septic fields,
selenium toxicity of emerging groundwaters resulting from increased
irrigation, and nitrate inputs into Chesapeake Bay from intensive
agriculture on the Eastern Shore are all examples of overloaded
filtering capacity.
The "dilution is the solution to the pollution" paradigm only
works for substances that do not partition to media other than
water and do not bioaccumulate. Nuisance growth of aquatic
macrophytes due to excessive nutrients and the food-chain
biomagnification of persistent pesticides are examples of
alternative fate-and- transport dynamics.
Groundwater contamination sources are very numerous and
ubiquitous (e.g., septic fields, injection wells, land
applications, material stockpiles, pipelines, and non-point
sources). Groundwater is generally slow moving and very
conservative in transformation functions. There are very little
data on groundwater as a source of ecological exposure. Most of
the exposure will occur in the future.
The Subcommittee ranked the ecological risks from groundwater
contamination to be relatively low. The major impact would be felt
by human consumers rather than ecological systems.
6.17 Pesticides
One of the side effects of pesticide use is environmental
contamination. Pesticides and herbicides are the only substances
that are intentionally applied to the environment because of their
biological toxicity. Society in general, and EPA in particular,
are aware of this, and pesticide regulation through registration
and reregistration, enforcement, and monitoring is currently of
high priority.
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The cost of pesticide development has increased dramatically,
and the number of compounds restricted or banned has increased
steadily in the last 20 years. The use of pesticides in the United
States increased during the 1970's, leveling off at a little over
one billion pounds of active ingredient since the mid- to late-
1970s. In fact, the amount of active ingredient used in the United
States in 1988 was 1.13 billion pounds, about the same as in 1978
(1.11 billion pounds). Clearly the degree of environmental
contamination and risk to the environment depend on such factors
such as toxicity of the pesticide, application methods, and its
persistence. We are concerned about this contamination and
encourage EPA to continue to develop environmental monitoring
methods.
We are also concerned by the efficiency of controls given
current application practices, in particular, the overuse of
pesticides and improper use by unskilled or untrained consumers and
farm workers. The different application approaches used which
depend on the type of pest, its location, and the specific type of
pesticide to be used can result in much of a pesticide sprayed on
the environment never reaching or impacting its target.
Research on non-pesticide control needs to be a priority for
EPA. Pesticides, by their very nature, are toxic to the
environment, and pollution prevention or non-use of pesticides
should be a long-term goal. We believe EPA should consider taking
a stronger role in non-chemical control of pests. Both research
and dissemination of information are needed.
6.18 Nev Toxic Chemicals (Non-Pesticides)
Determining the environmental risk posed by a chemical (s) that
has yet to be conceived or produced is impossible. The Toxic
Substance Control Act (TSCA) directs EPA to evaluate the hazards
and exposures associated with new industrial chemicals and
determine whether the potential risks are acceptable.
The EPA Unfinished Business background and reference documents
indicate that approximately one thousand new chemicals have been
developed each year over the past decade. It is further implied
that half are now in production. Laboratory toxicity assessments
have been conducted on some of the new chemicals reviewed by EPA's
Office of Toxic Substances since 1979. Many do not have adequate
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ecotoxicity data for a "reasoned ecological risk assessment", the
criterion specified in TSCA.
To compensate, in part, for the lack of time and resources to
conduct laboratory toxicity assessments, models have been developed
to estimate a variety of parameters, including bioconcentration,
toxicity, and persistence. Quantitative structure activity
relationship (QSAR) models are examples. It should be noted that
all models have limitations, and that models are not available to
estimate all parameters and responses for all chemicals.
As technologies advance and human population increases, it is
logical to assume that new chemicals will continue to be developed
and produced. If past practices continue, too many of these
chemicals will reach the marketplace with minimal or no toxicity
assessment. The Subcommittee recommends that the Agency carefully
evaluate its allocation of resources relative to toxicity
evaluations of new chemicals. Although the Agency did not rank
this problem area, the Subcommittee believes that it should rank
as a medium ecological risk.
6.19 Biotechnology
The subject of biotechnology includes a wide range of
disciplines, subject materials, and intended usage. For example,
developments in this field range from genetically engineered
microorganisms for use as microbial pesticides to plant life
altered to include heterogenetic material from a wide range of life
forms. Some of the concern associated with the utilization of
biotechnology reflects the manner in which biotechnology products
are derived; many of the developments suggested for biotechnology
utilize recombinant DNA technology. Other concerns focus on the
products of biotechnology and possible perturbations of the
environment that may result. The distinction between methods used
and the resulting products has been clearly delineated recently by
the Ecological Society of America (ESA, 1989). The substance of
this publication is summarized as follows: "We believe that these
developments should occur with the context of a scientifically-
based regulatory policy that encourages innovation without
compromising sound environmental management."
Recombinant DNA technology allows the potential for complete
description of altered homogenetic or heterogenetic hereditary
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material that might be included in the deliberate construction of
biological materials with altered properties. Therefore, risk can
be minimized, if not excluded, from the perspective of the genetic
material involved. The primary basis for concern, then, is the
behavior of the altered microorganism, plant, or animal species
into which this genetic material has been added. Such altered
species may have the potential for developing ascendant populations
that may alter delicate ecological balances indigenous to a given
environment. Such perturbations have the potential for overgrowth
of new species to the detriment of the normal flora and fauna.
Concerns for this possible result, then, must be ameliorated by the
development of acceptable criteria to exclude such outcomes prior
to the dissemination of these biotechnology products.
Bio-pesticides are agents that have been developed to
eliminate or diminish pests present in the environment. They are
usually defined in terms of their targets and include microbial,
insect, plant, and animal targets. Their efficacy is judged by
their ability to inhibit undesirable life forms and, therefore, are
generally pathogenic for the target organism. Two outcomes can be
envisaged from the release of such biotechnology products: a)
expansion of the host range (target species) to include organisms
beneficial to biological communities through mutations and
recombinations subsequent to release; and b) the ascendancy of
suppressed populations subsequent to the elimination of a pest
agent that normally limits such overgrowth. Therefore, two major
concerns are associated with these agents. The genetic stability
of the pesticide organism should be ascertained, and the
consequence of the removal of the pest from a biological community
should be evaluated. These concerns may best be addressed on a
case-by-case basis, reflecting the judgment of experts familiar
with the particulars of a planned usage.
Many developments in biotechnology center on the production
of plant life with altered characteristics. Here, as above, there
is a concern for the possibility that such plants might become
dominant to other beneficial life forms in a biological community
and, thus, have long-term detrimental consequences. However, such
concerns are also inherent to strain improvements accomplished
through traditional plant breeding technology. In the case of
biotechnology products and the recombinant DNA technology used for
their development, however, the biotechnology-derived products are
likely to be more concisely defined than the products of plant
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breeding. Therefore, concerns for biotechnology products should
be congruent with similar concerns associated with the release of
more conventional products.
One of the major ecological concerns prevalent today is the
accumulation, concentration, and leaching of xenobiotic compounds
into potable water supplies or their increased concentrations in
the atmosphere. These problems, to a large extent, are the
consequence of an industrial society and previous lack of concern
for environmental perturbations by its waste products. The .use of
genetically engineered microorganisms to degrade xenobiotic
compounds is envisaged as a logical extension of natural processes.
The beneficiation of such natural processes through the use of
recombinant DNA technology to produce microorganisms with enhanced
degradative characteristics is the primary thrust of these
developments. The usual object of such developments is the
enhancement of the rate at which natural processes occur and, in
some cases, an increase in the range of substrates that may be
degraded. For the safe application of such microorganisms, then,
a primary requisite is that these microorganisms not be pathogenic
to humans and other life forms. Of equal concern is the manner in
which commercial quantities of such microorganisms may be produced.
Commonly, microorganisms for commercial applications are grown in
nutrient solutions that allow attainment of high population levels
in a short period of time. There is, therefore, the opportunity
for growth of pathogenic microorganisms concurrently with the
commercial species, and such outcomes must be precluded by the
application of product standards. This concern, however, is
focused on manufacturing technology and not the biotechnology
product per se.
Pivotal issues concerning biotechnology products do not
include the methods by that such products are derived per se. They
do include the source of genetic material, the changes that have
been made to such genetic material, properties of the host organism
before and after alteration, the impact of release or escape of
genetically altered organisms on indigenous organisms, and their
dissemination to other ecosystems. To encourage innovation and
promote economic benefits to society, appropriate policies need to
be developed to regulate the content and usage of biotechnology
products. In some cases, this may require the development of new
regulatory purviews since these products lack precedent and,
therefore, are inappropriate for some existing regulatory policies.
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Regulatory agencies in place should take a proactive role toward
facilitating biotechnology developments by working in concert with
the developers of this technology and the end-users. A case-by-
case policy seems appropriate currently until experience with these
products is acquired.
The potential risk for biotechnology relates directly to the
product. Since products with disparate properties and intended
usage are being developed, it does not seem prudent to generalize
concerning inherent risk. However, no high-risk products should
be considered without exhaustive review. For example, special
consideration should be given to one possible product of
biotechnology, the genetic alteration of pathogenic species. With
microbial species, it has been suggested that genetic alterations
resulting in the loss of virulence, but maintenance of colonizing
activity by pathogens, might protect some plant species from
infection by pathogenic bacteria. However, it is not possible to
generalize in this regard, especially if all the traits
contributing to virulence are poorly understood. One may envisage
a genetic event occurring subsequent to release of such bacteria
that might introduce new, and possibly more virulent traits, into
an altered microorganism that has retained its colonizing activity
toward a target plant(s). Products beyond the foregoing
relationships, however, are likely to rank low to moderate risk
depending upon the information base relevant to the intended usage.
Biological entities, whose genetic potential and behavior are well
understood, are of less concern than those known to have been
developed from organisms clearly known to be associated with
undesirable biological activities.
6.20 Plastic in the Marine Environment
It is common to see plastic litter along roads, and on the
beaches and shorelines of our coastal environments. These
materials can exhibit an environmental impact in one of three ways:
aesthetic pollution; toxicity via ingestion; and mortalities from
entrapment and entanglement. The magnitude of the aesthetic
problem is relatively easily quantifiable. The number of
mortalities from ingestion, entrapment, or entanglement is much
more difficult to estimate accurately. The EPA Unfinished Business
background documents do a good job of relating the length of nets,
number of floats, length of ropes, number of traps, etc. in present
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use and the quantities lost from use and, thus, available to impact
marine and estuarine organisms.
Impacts can be severe for organisms that are particularly
prone to ingest plastics. Sea turtles are an important example.
Individuals of these endangered species have been shown to eat
plastics, and deaths have been attributed to such ingestions. Sea
birds are also vulnerable.
Since accurate estimates of the magnitudes of biological
impacts from plastics in the marine environment are not available,
it is difficult to rank the problem. However, since endangered
species are known to be impacted and the effects on fisheries have
the potential to be high, the Subcommittee concluded that the area
should be ranked as medium.
6.21 Biological Depletion and Extinctions
This topic was not a problem area specifically addressed or
ranked in the EPA Unfinished Business report on ecological risk
reduction. The Subcommittee feels that it is an important
ecological problem area and that it should be considered.
There is a consensus among ecologists that species extinctions
are occurring at unprecedented rates (Wilson, 1988; Wright, 1990).
Many species are lost before they can be described or
characterized. Others are known to be threatened or endangered,
and special efforts are made to protect them. As human populations
expand, there is increasing pressure on natural resources,
including species harvested for food and other uses.
The major cause of species extinctions and decreases in
natural populations is loss or disturbance of natural habitats.
Over-harvesting is an additional cause of population reduction of
commercial and sport species. When a species is lost completely,
through extinction, that genetic material, adapted to its
environment, is irreversibly lost. Similarly, when species become
threatened or endangered or natural populations are greatly
depleted, the gene pool is greatly reduced, possibly limiting the
ability of that species to adapt to environmental changes. In the
view of the Subcommittee, this problem area ranks as a high
ecological risk.
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6.22 Introduction of Biologic Species
Ecological communities are collections of biotic species that
have co-evolved clusters of interspecific interactions that impact
on increased probability of surviving for the participating
species. These interactions involve ecological processes such as
predation, competition, mutualism, symbiosis, and obligatory
physical associations. Many of these evolutionary associations are
so tightly coupled that small clusters of species have their fates
inseparably bound together.
Introductions by natural and anthropogenicly mediated events
have been analyzed by ecologists over the years, as these
constitute natural experiments with which to test hypotheses
involving community ecology. Generally, the frequency of
successful colonizations of exotic species is low when the
recipient community is not stressed. Propagules and transient
individuals are constantly testing the system to look for new
opportunities to expand their species domain. The resistance to
intruders comes from healthy endemic populations with the
competitive advantages of community co-evolution.
Even so, one of the most important demonstrable agents of
ecological change is the anthropogenic introduction of biologic
species into areas where they did not evolve. Intentional
introductions of sport fishes, game birds, horticultural varieties
of ornamental plants, and biologic agents chosen to control plant
and animal pests provide thousands of case examples. In addition,
a large number of accidental introductions have taken place
resulting from the worldwide network of material transport in
agriculture and forestry. Many of our most important pest
management problems involve accidental exotic introductions.
Introductions of exotic species have provided demonstrable
examples of total ecological disruption, such as the sea lamprey -
alewife destruction of fish communities in the Great Lakes. They
also provide examples of economic improvements with little evidence
of serious ecological impacts, such as the plantings of brown trout
in rivers and lakes throughout the United States. The wide array
of ecological responses to the introductions of exotic species
requires that each event be given careful evaluation prior to
implementation. Since introductions, if successful, are usually
irreversible, proactive evaluations should be mandatory.
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7.0 RECOMMENDATIONS AND CONCLUSIONS
1. Formalise an extramural and continuous process for ecological
risk prioritization; this process should not b« categorised by
Agency programmatic structure but rather by anthropogenic stresses
on the environment.
The 1987 "Unfinished Business11 report represented a pioneering
effort in assessing the relative risks of environmental stressors
and their prioritization for Agency attention. However, the
scientific process of relative risk ranking was influenced by the
programmatic structure of the Agency which influenced the
organizational approach to the study. Yet the study has already
been invaluable in affecting Agency operations. We recommend that
the process of risk assessment be continued as a formal working
tool of the Agency and that this process also include external
peers — for breadth of perspective as well as scientific
credibility. It is necessary that this process continuously
reappraise this nation's environmental issues and ecological risks
to focus and direct Agency activities.
2. invest in development of formal methodologies for ecological
risk assessment.
Although the ecological and welfare risk ranking procedures
used in our deliberations were a useful tool, these ad hoc
procedures represent only a beginning in quantifying and
formalizing risk prioritization. The process remains largely
nonquantitative. There is need to improve upon existing risk
ranking techniques and to evaluate methodologies for comparative
risk analysis. Programmatic resources should be invested, in both
in-house and extramural research and development, to improve
ecological and environmental risk evaluation and prioritization
methodologies. In addition, the overall concept of risk
minimization (implying both controls and corrective actions) needs
to be expanded to include proactive and anticipatory alternatives,
such as prediction and early detection of impacts, improved design
of environmental management systems, and utilization of recovery
processes and self-sustainability of natural systems rather than
human intervention and control.
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3. Develop the data bases needed for improving future •cological
risk assessments.
Ecological risk assessment is handicapped by the availability
of organized sets of comparable quantitative data to support the
risk evaluation process. The science itself lacks neither
concepts or data, but is deficient in systematic synthesis of
information into useful formats. All information is not
necessarily useful. The risk evaluation methodologies and state-
of-the-art techniques must define the data needs and data analyses.
Data bases supporting ecological risk assessments must be
institutionalized and maintained by the Agency. However, many
useful surveys assessing ecological health are maintained by other
Federal organizations. These must be accessed and used in the
final processes of relative risk evaluation and risk
prioritization, providing proper balance for risk reduction
actions.
4. Develop an appropriate paradigm for integrating ecological and
economic perspectives and considerations.
Any risk assessment must be based upon a comparison of
benefits and costs resulting from hazard reduction. Not all
environmental attributes and ecological values can be expressed in
economic terms. It will be necessary to develop an entirely new
paradigm for integrating ecological and economic considerations for
risk assessment. Understanding sustainable development limits for
ecological systems will be essential. Not until ecological and
economic values of environmental systems can be unified will it be
possible to obtain unbiased assessments of ecological worth,
accurately to prioritize stressors and systems at risk, and to
begin cost-effective strategies for risk reduction.
5. Expand EPA's perspective on ecological values and welfare risk
to include ecological attributes as veil as economic factors.
In developing an integrated ecological/economic paradigm for
environmental risk assessments, it will be extremely important to
address those many ecological attributes for which an economic
metric presently does not exist. The costs of remediation greatly
exceed expenditures to ensure early prevention of ecological
damage. To address the cost/benefit of environmental actions,
entirely new concepts of ecological attributes as finite resources
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and compounding rather than discounting when choosing alternatives
to environmental protection will be necessary.
6. Incorporate the results from this risk ranking process/
including the 1990 risk reduction study, in development of future
Agency policy and allocation of financial resources.
The 1987 "Unfinished Business11 report and this 1990 risk
reduction exercise by the RRRSC have demonstrated the need for new
directions in ecological research and applications. Using risk
assessment techniques, these reports provide opportunity for
renewed focus for reducing the risk to ecological systems based
upon scientific information and expert judgment. The opportunity
now exists to direct the Agency's efforts to those most critical
environmental problems where the greatest risk reduction can be
obtained. We urge the Agency now to incorporate the
recommendations from these studies into its future policy and
administrative operations.
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References cited
Baker, J.M., R.B. Clark and P.P. Kingston. 1990. Environmental
recovery in Prince William Sound and the Gulf of Alaska.
Inst. of Offshore Engineering, Heriot-Watt University, 12 pp.
Bartholomew, G.A. 1967. Seal and sea lion populations of the
California Islands. In: A.M. Philbrick, ed., Proc. Symp.
Biology of the California Islands, Santa Barbara Botanic
Gardens, Santa Barbara, CA, 229-244.
Bolin, B., J. Jager, and B.R. Doos. 1986. The greenhouse effect,
climatic change, and ecosystems: A synthesis of present
knowledge. Pp. 1-34. 3jn; Bolin, B., B.R. Doos, J. Jager,
and R.A. Warrick (eds.) The Greenhouse Effect. Climate Change.
and Ecosystems. SCOPE 29. John Wiley 6 Sons, Chichester,
U.K.
Bolle, H.J., W. Seiler, and B. Bolin. 1986. Other greenhouse
gases and aerosols. Pp. 157-203. In; Bolin, B., B.R. Doos,
J. Jager, and R.A. Warrick (eds.) The Greenhouse Effect,
Climate Change, and Ecosystems. SCOPE 29. John Wiley,
Chichester, U.K.
Broecker, W. 1987. Unpleasant surprises in the greenhouse?
Nature 328:123-126.
Charnley, G., E.A.C. Crouch, L.C. Green, and Lash, T.L. 1988.
Municipal solid waste landfilling: A review of environmental
effects. Rept. prepared by Meta Systems, Inc, Cambridge, MA,
November 16, 1988.
Davis, M.B. and D.B. Botkin. 1985. Sensitivity of cool-
temperature forests and their fossil pollen record to rapid
temperature change. Quaternary Res. 23:327-340.
Dickinson, R.E. 1986. How will climate change? Pp. 207-270. In;
Bolin, B., B.R. Doos, J. Jager, and R.A. Warrick (eds.) The
Greenhouse Effect. Climate Change, and Ecosystems. SCOPE 29.
John Wiley & Sons, Chichester, U.K.
71
-------
Eisenreich, S.J., Looney, B.B. and Thornton, J.D. 1981. Airborne
organic contaminants in the Great Lakes ecosystem. Environ.
Sci. Tech. 15:30-38.
Emanuel, W.R., H.H. Shugart, and M.P. Stevenson. 1985. Climatic
change and the broad scale distribution of terrestrial
ecosystem complexes. Climatic Change. 7:29-43.
EPA. 1987a. Unfinished Business: A Comparative Assessment of
Environmental Problems. Overview Report. U.S. EPA, Washington,
DC. 100 pp.
EPA. 1987b. Unfinished Business: A Comparative Assessment of
Environmental Problems. Appendix III. Ecological Risk Work
Group, Office of Policy Analysis, U.S. EPA, Washington, D.C.
EPA. I987c. Unfinished Business: A Comparative Assessment of
Environmental Problems, Appendix IV. Welfare Risk Work Group,
Office of Policy Analysis, U.S. EPA, Washington, DC.
EPA. 1988. Interim Sediment Criteria Values for Non-Polar
Hydrophobia Organic Contaminants. Office of Water, U.S. EPA
Washington, D.C., May, 1988.
EPA and UNEP. 1986. Effects of Changes on Stratospheric Ozone
and Global Climate. Volumes 1-4. U.S. Environmental
Protection Agency (EPA) and United Nations Environment Program
(UNEP). U.S. EPA, Washington, D.C.
ESA. 1989. Ecology 7_P_: 298-315.
Federal Register, Thursday, June 26, 1986, pp. 23302-23393.
Federal Register, Tuesday, June 16, 1987, pp. 22892-22915.
Franklin Associates, Ltd. 1988. Characterization of municipal
solid waste in the United States, 1960 to 2000. USEPA, Office
of Solid Waste and Emergency Response. EPA/SW-88-033.
Hansen, J. and S. Lebedeff. 1988. Global surface air
temperatures: update through 1987. Geophvs. Res. Ltrs.
15(4): 323-326.
72
-------
Hansen, J., A. Lacis, D. Rind, G. Russell, P. Stone, I. Fung, R.
Ruedy, and J. Lerner. 1984. Climate sensitivity: analysis
of feedback mechanisms. Pp. 130-163. In; J. Hansen and T.
Takahashi (eds.) Climate Processes and Climate Sensitivity.
Amer. Geophys. Union, Washington, D.C.
Hanson, K., G.A. Maul, and T.R. Karl. 1989. Are atmospheric
"greenhouse" effects apparent in the climatic record of the
contiguous U.S. (1985-1987)? Geophvs. Res. Ltrs. 16(1):49-
52.
Harwell, M.A., T.C. Hutchinson, with W.P. Cropper, Jr., C.C.
Harwell, and H.D. Grover. 1985a. The Human and Environmental
Consequences of Nuclear -War. Vol. II. Ecological and
Agricultural Effects. John Wiley and Sons, Chichester, U.K.
523 pp.
Harwell, M.A., T.C. Hutchinson, W.P. Cropper, and C.C. Harwell.
1985b. Vulnerability of ecological systems to climatic
effects of nuclear war. Pp. 81-172. In; Harwell, M.A., T.C.
Hutchinson, with W.P. Cropper, Jr., C.C. Harwell, and H.D.
Grover. The Human and Environmental Consequences of Nuclear
War. Vol. II. Ecological and Agricultural Effects. John
Wiley and Sons, Chichester, U.K.
Harwell, M.A. and J.R. Kelly. 1986. Ecosystems Research Center
Workshop on Ecological Effects from Environmental Stresses.
Ecosystems Research Center, Cornell University, Ithaca, NY.
42 pp.
Hoffman, J.S. 1987. Assessing the Risks of Trace Gases That Can
Modify the Stratosphere. Volume I. Executive Summary. U.S.
Environmental Protection Agency, Office of Air and Radiation,
Washington, D.C.
Huddleston, R.L., J.E. Rucker, K.W. Brown, and Deuel, L.E. 1982.
Evaluation of subsurface effects of long-term landfarming.
In Land Disposal of Hazardous Waste. Proc. 8th Annual
Research Symposium. EPA-600/9-82-002:398-446.
Idso, S.B. 1989. Carbon Dioxide and Global Change: Earth in
Transition, IBR Press, Tempe, AZ 292 pp.
73
-------
Jones and Parker. 1990. Global wanning continues in 1989. Science
247:521.
Jordan III, W.R., R.L. Peters II, and E.B. Allen. 1988. Ecological
restoration as a strategy for conserving biological diversity.
Environ. Mgmt. 12(1):55-72.
Keeling, C.D., R.B. Bacaslow, and T.P. Whorf. 1982. Measurements
of the concentration of carbon dioxide at Mauna Loa
Observatory, Hawaii. Pp. 377-385. In; Clark, W.C. (ed.)
Carbon Dioxide Review; 1982. Oxford Press, New York.
Kerr, R.A. 1989. Hansen vs. the world on the greenhouse threat.
Science 244: 1041-1043.
Lashof, D.A. and D.A. Tirpak (eds.). 1989. Policy Options for
Stabilizing Global Climate. Report to Congress (draft). U.S.
Environmental Protection Agency, Office of Policy, Planning
and Evaluation, Washington, D.C.
Lindstedt-Siva, J. 1984. Oil spill response and ecological
impacts - 15 years beyond Santa Barbara. MTS Journal
18(3):43-50.
Lucero, G. and K. Moertl 1989. Superfund Handbook: A guide to
managing responses to toxic releases under Superfund. ENSR
Corp, Acton, HA, 150 pp.
MacCracken, M.C. and P.M. Luther (eds.) 1985. Projectina the
Climatic Effects of Increasing Carbon Dioxide. DOE/ER 0237.
U.S. Department of Energy, Washington, D.C. 381 pp.
Millar, C.I, and L. D. Ford. 1988. Managing for nature
conservation. Bioscience 38(7):456-457.
NAPAP. 1987. Vol. I-IV, interim Assessment, The Causes and Effects
of Acidic Deposition. National Acid Precipitation Assessment
Program, Washington, DC.
NAPAP. 1989. Assessment Plan Update. National Acid Precipitation
Assessment Program, Washington, DC.
74
-------
NAS. 1979. Carbon Dioxide and Climate; A Scientific Assessment.
National Academy Press, Washington, D.C.
HAS. 1983. Changing Climate. National Academy Press, Washington,
D.C.
NAS. 1987. Current Issues in Atmospheric Change. National Academy
Press, Washington, D.C.
NAS. 1989. Biologic Markers of Air-Pollution Stress and Damage
in Forests. National Research Council. National Academy
Press, Washington, DC.
Nelson-Horchler, J. 1988. Hazardous waste: Who wants it?
Industry Weekly, February 14, 1988, 56-58.
NRC. 1985. Oil in the Sea: Inputs, fates and effects. National
Research Council. National Academy Press, Washington, D.C.
Parry, M.L., T.R. Carter, and N.T. Konijn (eds.) 1988a. The
Impact of Climatic Variations on Agriculture. Volume I:
Assessments in Cool Temperate and Cold Regions. Reidel,
Dordrecht, The Netherlands.
Parry, M.L., T.R. Carter, and N.T. Konijn (eds.) 1988b. The
Impact of Climatic Variations on Agriculture. Volume II;
Assessments in Semi-Arid Regions. Kluwer Academic Publishers,
Boston, MA.
Peirce, J.J. and P.A. Vesilind. 1981. Hazardous Waste Management.
Ann Arbor Science, Ann Arbor, MI, 190 pp.
Piasecki, B. and G.A. Davis. 1987. America's Future in Toxic
Waste Management: Lesson from Europe. Quorum Books,
Greenwood, NC, 320 pp.
Pohland, F.G., Dertien, J.T. and Gosh, S.B. 1983. Leachate and gas
quality changes during landfill stabilization of municipal
refuse. Presented at Third International Symposium on
Anaerobic Digestion. August 14-19, 1983, Boston, MA.
75
-------
Robock, A. 1983. Ice and snow feedbacks and the latitudinal and
seasonal distribution of climate sensitivity. J. Atmoa. Sci.
40:986-997.
Rowland, F.S. 1988. Some aspects of chemistry in the springtime
Antarctic stratosphere. In: F.S. Rowland and I.S.A. Isaksen
(eds). The Changing Atmosphere. John Wiley and Sons, U.K.
281 pp.
SAB. 1988. Future Risk: Research Strategies for the 1990's.
Science Advisory Board, U.S. EPA. Washington, DC.
Shea, C.P. 1989. Protecting the ozone layer. In State of the
World 1989? A WorldWatch Institute Report on Progress Toward
a Sustainable Society. W.W. Norton Co., New York, 256 pp.
Smith, J. and D. Tirpak (eds.). 1989. The Potential Effects of
Global Climate Change on the United States. U.S.
Environmental Protection Agency, Washington, D.C.
Stegen, R.L., W.J. Gresham and Carlson, M.E. 1987. Unified ground
water monitoring program. Waste Management of North America,
Northeast Region.
Stolarski, R.S. 1988. Changes in ozone over the Antarctic. In:
F.S. Rowland and I.S.A. Isaksen (eds.). The Changing
Atmosphere. John Wiley and Sons, U.K. 281 pp.
Stommel, H. and E. Stommel. 1979. The year without a summer.
Sci. Amer. 240:176-183.
Strachan, W.M.J. and Eisenreich, S.J. 1988. Mass Balancing of
Toxic Chemicals in the Great Lakes: The Role of Atmospheric
Deposition. Report of the International Joint Commission,
Windsor, Ontario, 113 pp.
Travis, C.C. and A.D. Arms, 1988. "Bioconcentrations of Organics
in Beef, Milk, and Vegetation", Environ. Sci. Technol. 22,
271 (1988).
Uchijima, Z. 1981. Yield variability of crops in Japan. Geo.
Journal 5:151-164.
76
-------
Uchijima, Z. 1982. Microclimate and rice production. Korean J.
Crop Sci. 27:314-339.
Webster, I.A. 1988. Municipal solid waste landfills - the role
of industrial wastes in those landfills. In M.M. Varma and
J.H. Johnson, Jr. (eds.) Hazardous and Industrial Waste,
Proceedings of the 20th Mid-Atlantic Industrial Waste
Conference. Hazardous Materials Control Research Inst. 377-
382.
Wigley, T.M.L. 1988. Future CFC concentrations under the Montreal
Protocol and their greenhouse-effect implications. Nature
335:333-335.
Wilson, E.O. (ed.). 1988. Biodiversity. National Academy Press,
521 pp.
Wood, J.A. and M.L. Porter. 1986. Hazardous pollutants in Class
II landfills. South Coast Air Quality Management District,
El Monte, CA.
Woodhouse, C.D. 1975. Santa Barbara's mermaids. Museum Talk
49(4):92-92.
Worrest, R.C. 1985. Responses and effects of UV-B. In: Harwell,
M.A., T.C. Hutchinson, with W.P. Cropper, Jr., C.C. Harwell,
and H.D. Grover. 1985a. The Human and Environmental
Consequences of Nuclear War. Vol. II. Ecological and
Agricultural Effects. John Wiley and Sons. Chichester, U.K.
523 pp.
Wright, D.H. 1990. Human impacts on energy flow through natural
ecosystems and implications for species endangerment. Ambio.
12(4):189-194.
77
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