v-xEPA
United States
Environmental Protection
Agency
Science Advisory
Board
(A-101)
EPASAB-EC-30-021A
September 1990
The Report Of
The Ecology And Welfare
Subcommittee
Relative Risk
Reduction Project
Reducing Risk
Appendix A
Printed on Recycled Paper
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NOTICE
This report his 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 problem* 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 ioard (SAB) reviewed the
ecological and welfare component* of the Agency** isg? 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 EPA1* 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 food »echani»» to formulate public
policy from a scientific base of data and »«chani»tic processes and
recommended that the Agency institutionalise this approach on a
regular basis, providing the trained personnel and scientific data-
bases needed to establish a scientific credibility for the process,
Kev Words; ecological risk assessment; risk reduction; welfare
risk assessment
ii
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U.S. ENVIRONMENTAL PROTECTION AGENEC,¥;
"'"'•"•";'v;;": SCIENCE "ADVISOR* BOARD '"'""
RELATIVE RISK REDUCTION STRATEGIES COMMITTEE
and Welfare Subcomuittce
Chairman
Dr. William Cooper, Chairman, Zoology Department, Michigan State
University, East Lancing, Michigan
Member;
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 Institot* of Marine Science,
College of William and Mary, Saaford, Virginia
Dr, Ronald Qlsen, Professor of Microbiology and Associate vice
President for Research, University of Michigan Medical
School, Ann Arbor, Michigan
Dr. David Reichle, Associate Director of Biomedical and
Environmental Sciences, Oak Ridge National Laboratory,
Oak Ridge, Tennessee
Dr. June Lindstedt-Siva, Manager of Environmental Science, ARCQ,
Los Angeles, California
Science Advisory BoardStaff
Mr. Robert riaak, Acting Assistant Oir«ctor, 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 thi* 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 croundwater ....... 15
3.2.6 Haste 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 ....... i?
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
S.O WELFARE RISK ANALYSIS 28
5.1 Background .... ......... 28
5.2 Subcommittee Findings ............... 28
5.2.1 Critique of Appendix IV 29
5.2.2 Su*t»inability 30
5.2.3 Willingness to Pay 31
5.2.4 Multiplier Concept ........... 32
5,3 Welfare Rick Paradigm ........ 33
5.3.1 Ecological Quality 33
5.3.2 Resource Sustainability ......... 33
5-3.3 Direct Effect* - Economic* ....... 34
5.3.4 Direct Effects - Non-Economic ...... 34
5.4 Welfare Risk Ranking* of the Subcommittee ..... 34
6.0 UPDATES ON RISK CATEGORIES 37
e.i Criteria and Toxic Air Pollutants ......... 38
6.2 Radiation from Source* Other than Indoor Radon . . 39
6.3 Stratospheric Ozone Depletion . ..... 40
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€.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 Maters
Plus in-Place Toxics in Sediments 46
6,7 Contaminated Sludge .,.».,»......... 48
6,8 Physical Alteration of Aguatie Habitat* ...... 49
6.9 Active Hazardous Waste Sites ........... 50
€.10 Inactive Hazardous Waste Sites . ... SI
€.11 Municipal and Industrial Non-Hazardous Haste
Sites ................ * - .. - S3
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 Groundvater Contamination ............. 59
6.17 Pesticides ........ ...... 60
6,18 New Toxic Chemicals (Non-Pesticides) ....... 6i
6.19 Biotechnology ................... 62
6.20 Plastic in the Marine Environment . , . 65
6.21 Biological Depletion and Extinctions ....... 66
£.22 introduction of Biologic Species ... 67
7.0 RECOMMENDATIONS AND CONCLUSIONS ............ €8
REFERENCES CITED ........... ... 71
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LIST OP TABLES
Table I
Table II
Table III
Table iv
Table V
Table VI
Table VII
Table VIII
Table IX
Table X
Table XI
Developing a Hierarchy of Relative Risk .... 2
Assessing Welfare Risks ...... 3
Original EPA List of Environmental
Problems .*.,.....,....... lo
Classification of Problem Areas Relative
to Size, Hazard, and Exposure 13
Ecological Rick Matrix ..... .18
List of Ecosystem Types ............ 19
Ranking of Ecological Risks Characterized
by Scale of Stress ..... 21
Summary of Ecological Risk Rankings
(From Tables VII, IX, « X) ........ 23
Ranking of Ecological Risks Characterized
by Mediua ................ 24
Time for Ecological Recovery ......... 26
Integrated Welfare Rankings .......... 36
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l.P
This is the report of the Ecology and Welfare Subcommittee of
the Relative Rick 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 m 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 tile 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 EPA1*
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 ti*e 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 tine (years, decades, centuries/
indefinite) (see Table I, next page).
The ecological problem areas that ve consistently ranked the
highest vere habitat alteration .
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Table I - Developing a Hierarchy of
Relative Risk
Diagnostic Parameters
Aggregated Problem Areas
Intensity of Pottntlil Ef fact*
Une*rt»lnU*« of th*a* Ettimat**
Typ* of Ecological R*ipon**«
Tim* Scat* for R*cov«ry
Following Removal of Straa*
- Seal* of $tr*t* (local, rational
Woaph*r»>
- Transport Madia (air, watar,
t*rr»*tri»l)
- ftacovary Tim* (yaara, d«e»d»m,
eanturlaa /IndoffnK*)
stratospheric ozonedepletion (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 tines are estimated to be up to centuries. Ecological
systems are well adapted to recover from many type* 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 « species if its habitat
cannot be protected.
The Subcommittee ranked the problem areas of airborne toxics.
toxicsin 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 Metal* and organic*)
that are transported by air and water and nay be bio*ccumulat*d 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 discharge* to surface
waters generate local and regional impacts. Wie 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 pf impacts in tine makes no sense ecologically. We defined
four types of welfare impacts: ecological miali^yr rftsourcy
iistainabi1itv. direct effects-economic, and direct effects-non
economic (Table II). The ecological impact* 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 impact* 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
y«s
Indirect impact* on humans that result
from a reduced quality of an
environmental resource and dsereassd
human utility (Reversible)
Rssourc* Suttalnablllty
irreversible losses of ecosystem
structure and functions, such as loss
of critical habitat or specie* extinctions
Dir*ct Effects - Economic
no
Direct physical Changs* that caus*
adverse economic Impacts on humans
other than iteaith effects
Direct Ef f eets-Nort Economic
yes
Primarily Involves social nuisances such
as odors, noise, *n4 reduced
The direct effects-economic ricks could not be ranked as the
data needed to perform a credible benefit/risk analysis are not
available. The Subcommittee did rank the direct *ff«cts-non
economic risks. These involve noise, odor, vistasf end
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 program* to
address the environmental problem* of greatest concern i«
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.
€} EPA should five more consideration to non-economic aspects
of ecological values and velfare 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 provid* the trained personnel end
scientific data-bases needed to establish * scientific credibility
for the process.
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2.0 11ITROPTCTI01I
2.1 Background
••In its 1988 report on research strategies for the I990*s,
"Future Risk", the Science Advisory Board recommended that th*
concept of risk reduction be used nor* broadly In EPA (SAB, 1938),
As a follow-up to that report, EPA Administrator William X. Reilly
requested that the SAB bring it* 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 198? 1PA report "Unfinished Business; A Comparative Assessment
of Environmental Problems" (EPA, I987a,b,c). This EPA document
reports on the findings of EPA senior staff who evaluated more than
two dozen environmental problems in terns of their relative
environmental risks. These problems were evaluated within four
broad categories: cancer risk, non-cancer health risk, ecological
risk, and velfare 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
velfare 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 velfare risks (i.e., environmental risks).
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c) Provide optional strategics for reducing major risks,
d) Develop a long-term strategy for improving the methodology
for assessing and ranking ricks to human health and the environment
and for assessing the alternative strategies that can reduce risks.
2.2 Charge to the Beolocrv and.Welfare ^^ifeg?BffiittTT
This document was prepared toy the Ecology and Welfare
Subcommittee, a subcommittee of the Relative Risk Reduction
Strategies Committee (RRRSC) of th* 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 1986-8? 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*1 (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
Business11 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,
1.3 Format ef this Report •
In addition to an pxeeutive _jjjjujpiarv• *n Intrqduc^ijgfl f and a
list of cited References, this report contains five major sections.
Section 3.0. Environmental Problem Areas, represents a further
aggregation of th* programmatic areas into eight general areas of
environmental problems. The Subcommittee member* were unanimous
in their dissatisfaction with the original EPA list of problem
areas that mixed sources, receptors, madia, and specific regulatory
obligations. Tills 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 CPA's ragtilatory purviaw. „ .. .,, _ ,.,*.,*.., .
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As a first *tep. beyond the ,1986..procedures carried out by EPA,
the Subcommittee " examined the' original 31 EPA ' categories of
environmental problem areas. Some of these vere combined when ve
felt there were no differences in ecological risk (e.g., municipal
and industrial non-hazardous waste sites); others vere 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.D, 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 Stnf Welfare Risk Analysis, critiques the "Appendix
IV - Welfare Risk Assessment" and presents an alternative paradigm.
Four classes of welfare iapacts 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 *
Economic1* category requires specific economic data that were not
available to the Subcommittee. Thus, no atteapt was made by the
Subcommittee to develop an economic ranking. A sunmary of welfare
risk rankings combining the aspects of the other three categories
was developed.
Section €.0, Updates enftisk Categories, contains critiques
of the problem areas, providing additional information to update
these topics.
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Section 7.Q. Reeonftaendations and Conclus^gns. presents six
major recommendations developed by the Subcommittee to assist the
Agency's capability to assess onvirorunental risks.
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3.0 EKVIROKKEKTAL PROBLEM
3.1 Limitation* of MM
The Subcommittee was asked to address the EPA-specified list
of the thirty-one environmental problem areas (Initially developed
tor the IPA comparative Risk Project - see Table III, pag« 10) in
order for its results to be comparable with other evaluation*
(i.e. f Hunan Health and Strategic Options Subcommittees) „ However,
it was clear to the Subcommittee that the listed problem area* 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-hazardou» industrial
sites); each category is divided based acre on how they are
regulated within EPA than on the types of stresses they nay 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, on* category includes all inputs to
estuaries, coastal waters, and oceans from all sources, whereas
another category consists only of accidental releases front oil
spills.
Consequently, individual categories of the thirty-one
environmental problem areas often contained many different types
of environmental stresses. For example, IPA 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
particulars). 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
freshwater1*and terrestrial ecosystems involving pH stress, aluminum
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Table HI - Original EPA List of
Environmental Problems
1 - Crltarla air pollutants from mobJla it stationary sourca*; acid dtposltlon
2 - Hazardous/toxic air pollutant*
3 - Othar air pollutant*, (s.g,, flourtdas, total raducad aulfur)
4 - Radon (Indoor pollution only)
S - Indoor air pollution (othar than radon)
£ - Radiation (othar than radon)
7 - $ub*tancas suapaetad of dapfatlrtf atratoaphsrle ozoita layar
8 - Carbon dloxlda and global warming
9 - Diraet polnt-tourca dischargaa to surfaca watar* - Induatrlat aourca*
10 - Indlract polnt-aeurea dlschsrga* to aurfaea watara - POTWa
11 - Non-point aourca discharges to aurfaea watar plus In-placa
toxiea In aadlmanta
12 - Contamlnatad slydga (Includaa municipal and acrubbar aludgat)
13 - Dlsehargas to aatuarla*. eoaatal watara, and ecaana from all aourcaa
14 - Dlachargat to watlanda from all aoureat
16 - Drinking watar at tha tap (inctudaa charnlcal*, toad from
plpa, biological contaminanta, radiation, ate)
16 - Actlva hazardoua waata altaa (Includaa hazardoua waata
tanks, Inputi to groundwatar and othar madia)
17 - Inactlva hazardoua waata altaa (Includaa Suparfund, input*
to groundwatar and othar madia)
18 - Municipal non-hazardoua waata altaa (Inputa to groundwatar & othar madia)
10 - Industrial non-hazardoua waata altaa (Includaa utllitlaa)
20 - Mining waataa (a.g,, oil and ga* axtraetlon waataa)
21 - Aeeldantal ralaatas of toxic* (all madia)
12 - Aeeldantal ral*a*aa from oil apllla
23 - Ralaasaa from storaga tanks (Includa* product ft patroiaum tanka)
24 - Othar groundwatar contamination (aaptlc tanks, road aalt, Injactlon walls)
25 - Pattlclda rasldua* on food aatan by human* or wNdllfa
16 - Application of paatlcldaa (Includaa risk to paatlclda workar* a*
eontumara who apply pa*tleldaa)
27 - Othar pa*tlclda rlaka (laaenlng, run-off, air dapoaltlon from spraying)
29 - Naw toxic chamicai*
28- Blotachnology (anvlronmantal ralaaaaa of ganaticany altarad organisms)
30 - Conaumar product axpoaur*
31 - Workar axpoaura to ehamlcal*
Modiflad from; EPA Raport "UnfInlahad Buslnaa*: A Comparative Aaaassmant
of tnvlronmantal Problamf pagai 10-11. (EPA, 10S7a),
10
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toxicity, changes in redox potential, enhanced.susceptibility to
disease and p«st infestations, differential «ff«ct» on competitive
interaction* in ecological communities, and a host of ether
problems. Thus, the relative risks to the environment from this
•ingle 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 nodes 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, !0, 11 f 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 IPA 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
examplei 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 Here taken: 1) aggregation of
related EFA environmental problem areas Into a more limited number
of categories, followed by ranking of those categories based on
Subcommittee-developed criteria? end 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
11
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to the EPA list being considered by the Human Health and strategic
Options Subcommittee*. 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 risk*.
$.2
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 vas
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 vas 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 vas 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 1FA 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.
a.2.1
Although one sight be tempted to separate global warming
and stratospheric ozone (?) from criteria air pollutants (l) and
hazardous air pollutants (2), the fact remain* that all of the
-------
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
S,10,11,2Q
12,28,27
13,14,20
23,29
16,17,18,1i
21,22
28,20
Size
Global
Glob /Reg
Regional
Loci!
Local
Local
Local
?
b
Hazard
High
High
High
Lew-Mi
Low
Low
f
?
Exposure
High
High
High
N/A
Low
Low
L«w/HI
?
8 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
13
-------
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 a* the generation
of sulfates and, thus, acid rain. Burning of fossil fuels leads
not only to the increase in carbon dioxide level* 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 1,2,3,7,4 8.
3,2.2 Surface, pater tEnvironmental Problems t-11.201
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.J.3 toil (Environmental Problems ia.as.2€i
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.
Environmental problem areas 13 and 14 consider the physical
alteration of aquatic habitats and ere therefore grouped together.
Problem area 20, which Is concerned with mining wastes, could be
partially in this category given that mining Activities end mining
waste can lead to physical habitat alteration. Thus, regardless
of the affected media, habitat alteration should b« considered as
a single group,
14
-------
3*2*5 flroundvater fEfivironaiental Problems 23/2SO
Problem areas 23 and 29 consider release from storage tanks
and other groundwater contamination sources. Since groundwater
protection is the focus, groundwater should be the category of
concern.
3 . 2 » 6 Waste Bites
Environmental problem areas 16-19 Involve various types of
waste sites and, thus, should be grouped under the same category,
3.2,7 Aeeideptal Rele»8*s fgnvircattental Problem Ureas 2l>221
Accidental releases of toxics (21) and oil spills (22} are
both in the category of accidental releases and should be
considered under the came class.
3,2*1 Kev chfaieali and New Technology fEnviro_ni>*pt*l Problem
ftreaa 28.29)
Biotechnology (29) and the category of new chemicals (28)
represent new ventures that are designed for the introduction of
nev materials or chemicals. Since there is a lack of information
regarding the potential effects from these unknown sources of
potential contaminants, problem areas 18 and 29 are grouped into
a single problem area. It is important to note that although this
area was ranked lowest in priority, this vas 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 i>« associated
with new chemicals and processes whether chemical or biological.
15
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4.0 XLTZKKATIVE MODEL
4.1
The second approach that th« 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, I987b)) that detailed a
methodology for ecological risk ranking. Specifically, that
original panel: i) 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 fi) utilizing this matrix and a set of panel-developed
criteria discussed below, ranked the list of environmental stresses
with respect to potential environmental risk*.
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
-------
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. 3 Li»t ef Eflviyef^ifafral Stresses Considered
The Subcommittee began with the list of environmental stresses
presented in Harwell and Kelly (1986). The list vas reconsidered
with respect to the need for wording changes as well as any missing
environmental stresses that should be added. A revised list vas
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 Ecosystem/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 vas accepted
by the Subcommittee without revision (Table VI, see page 19}.
The potential for ecological effects from each environmental
stress vere 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
*ras based in part on the background information provided by EPA to
the panel, but vas primarily based on the expertise and experience
of the ecological panel. ., -..$£* -•• ;:- . .
••" -' > € -*".** f T
2) The nature of the ecological effect from each specific
environmental stress, categorized as; a) potential effects on
biotic community structure, such a* alterations in the trophic
structure, changes in species diversity or richness, or other
17
-------
Table V - Ecological Risk Matrix
AW SOURCES
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-------
Table VI - List of Ecosystem Types
Freshwater Ecosystems Marine and Estuarlne Ecosystems
- buffered t«kei * coattal eeo«y*tem«
- unbuffered lake* * open ocean ecotyatem*
* buffered ttream* - estuaries
- unbuffered atreama
Terrestrial Ecosystems Wetland Ecosystems
- conif ereu* foreete - buffered f reahwater leolated wetland*
- deelduoua fore*ta * unbuffered frethwater (totaled wetland*
- §raaaland ecosyatem* - freshwater flowing wetland*
- desert fc aeml-arid eco*y*tem* * ealtwater wetland*
• alpine and tundra eeotyttema
community-level indicators of disturbance; b) potential effects on
ecological processes, *uch 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; end
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
-------
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 affects, type of «cological response, uncertainties about
the estimate, and time scale for ecological recovery) (Table 4 in
Harwell and Kelly, 1986}. Th« 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 Business1* 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 EnvjjFprunontal Stress Ranking* bv scale
The results of the Devaluation 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 «nd 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 vas done to indicate
20
-------
Table VII - Ranking of Ecological Risks Characterized
by Scale of Stress *
Ecological Risk
Biosphere
Increasing Scale of Stress
Regional
Ecosystem (locat)
Global Climate
Stratospheric Ozons
Global CHmat*
Stratospheric Ozone
Habitat Alteration
Global Climate
Stratospheric Ozone
Habitat Alteration
Biological Depletion <*>
Habitat Alteration
Airborne Toxic*
Biological Depletion (*>
Afrborne Toxic*
Tonic* In Surface Waters
Pe*tlclde*/H«rblc1de«
Acid Dep otltlon
O Level* of High
Ccotegleftl Rl*k
ere Menltfled)
AcNt Depo»Hlon
Nutrient*
Acid Inpot* to Surface
Waters
Airborne Tox tee
MtcHurn
Toxic* In Surface Wat*r*
H*rblcWe*/Pe*»»cld»«
BOD
TurbldHy
Oi
Low
Oroundwater Conlamtnatlon
Radio nucttd**
CMorlnsJIon
Thermal Pollution
Qroundwater Contamination
In som» cases,
Wghrlsk
Deltberate Release of
Genet Icatty Engineered
Organftma
Introduced Specie* <")
Deliberate Beleaae of
QenetkkHy Engineered
Organfama
Introduced Species (•)
* TtM»M problem areaa not tttedln each coKimn were deemed not to be ecotoglcaBy algnlfleant at lhat «cate,
(*) Refers to profetem area* not ortghtatty Hated by EPA.
-------
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
understanding of these issues by the Subcommittee members than by
the original panel? and 6) adding the globally transported airborne
toxics to the global-seal* "medium ecological importance" category.
In addition to these modifications, the Subcommittee
subdivided the previous "high ecological importance" category into
three subcategories to reflect a differentiation in the level of
concern about the environmental stresses in the high category.
Consequently six rankings exist in the Subcommittee's final scheme
(Tabl* VIII, see page 23)! EHH for highest potential ecological
risk, HH for next highest ecological risk, H for high ecological
risk, M for medium ecological risk, L for low ecological rick, plus
a category of "in some cases high risk" effects. The latter
category was established to cover environmental issues such as the
deliberate release of genetically engineered organisms, in which
most inputs to the environment would likely have little or no
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
The Subcommittee also considered the relative importance of
ecological effects of the environmental stresses, separated by
transport media (air, vater, 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 rathe? than by spatial scale. A new matrix of ecological
risk rankings (Table IX, s«« 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
-------
Table VIII - Summary of Ecological Risk Rankings*
(Taken from Tables VII, IX and X)
Environmental Stress
1. Global CNmat*
Habitat Alteration
Stratospheric Ozone
Btotoojcel Itepfetteit {«>
2. tferfeteMea/PeetlcMe*
3, Toftfee hi Surface Wal*r*
AcM Deposition
Airborne Tonic •
4. Nutrftente
BOD
TurMdHy
5.01
QrountfwalMP
0, HadtOflUCaoee
AcM Input* to Surf ace Waters
Thermal Pollution (•>
Extent of Stress
•!••»».»•
jHtt t
HWI
HH
HHH
M
H*i*Miif
HHH
HHH
HHH
HH
M
M
M
HH
L
L
tc«*r«tMH
HHH ~
HHH
HHH
HHH
HH
HH
H
HH
H
M
M
M
L
L
H
L
Media
**
HHH
HHH
HH
H
HH*
L
W*l*r
HHH
HH
HH*
HH*
H
M
M
M
L
L
H
L
f«t«*i»irt
HHH
HH
1
_.&•«
_ tkHt
X
X
X
X
X
overy T
MxMwm
X
X
X
X
X
X
X
inw^
i««
X
X
X
X
X
fj tfHM»MH»H»M»L - Wt»f« HHH " HtCHCST; HH " HIGHER; H • HIGH; M - MEDIUM; L
* R*f «r« t* proMwn «r*H iwt cfHPnaNy ttt*d by EPA.
* TtMM* pn>M*m www iirt lhrt«d hi «eh cofumnw«r«
-------
Table IX - Ranking of Ecological Risks Characterized
by Medium8
Ecological
AIT
Wafer
T«rr*strlal
Global CHm»l«
Stratospheric Oxono
Habit*) Alteration
Habitat Alteration
Hlflli
(3 L*va+a of High
EcotogteaJ HliH
«r* Ntontlffod)
Rogfonal/Local Transport
Air from* Tomte*
PMtteldM/HorMclifot
Biological Captation {•)
Toxic* (local)
P«*tkkf*a and Herbtcld»»
(local)
Biological D«f>l«tlon (*)
AcM
Nutrlmta
Acid InpuU
Global Tran*port
Alrl»OfiM Tonic*
HMKHUHI
ON
BOD
Toxlct (rational)
Turbidity
H*rMcM**/f»**ttcl
-------
times. If a stress was considered to^cause & very,long-tera effect
on an ecosystem, then it would be ranked higher than a stress to
which the ecosystem could recover nor* rapidly, The Subcommittee
decided that this information, if made more explicit, would be
useful to decision maker* in evaluating policy options, especially
if combined with an estimate of the tine 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, s«« 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
vas 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.
The final ecological risk ranking prepared by the Subcommittee
is « synthesis of the above matrices. This ranking is provided
(Table VIII, «ee page 23) to giv* 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
-------
Table X - Time for Ecological Recovery
Increasing Recovery Tim*
Environmental Stress
i
i
i
i
j
*
i
\
f
t
9
;
I
D
1
1, Global CllmaU
Habitat Alteration
Stratoaph«rlc Ozon*
Biological Ot pt«tlon
3. H«rblcld«»/P«tUeld#«
3. Toxic* In Surface Waters
Acid Depotltlon
Airborne Toxlct
4, Nytrlentt
BOD
Turbidity
S. OH
Greundwater
0, Radlonuc»de»
Add Inputt to Surface Water*
Solid Wat tee
Thermal Pollution
In torn* case*, High Risk:
Deliberate Release of
Genetically-engineered
organiem*
Introduced Speclee
Short
(Year*)
X
X
X
X
X
X
X
Medium
(Decade*)
X
X
X
X
X
X
X
X
X
Long
(Centuries)
X
X
X
X
X
X
X
26
-------
present ecological risk assessment capabilities. However, the
synthesis ranking developed by ,.;the ^Subcommittee-is, not arbitrary,
but, rather, is based on criteria of th* 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 VIZI (««* 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.
Consequentlyf 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 vithin 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 «mphasis vithin EPA
and, indeed, include some aspects not presently vithin the
legislative mandate of the Agency (especially issues of habitat
alteration, for which EPX'» 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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i.§ WTLyjLRJ RISK
S.I
The Subcommittee was charged with three specific tasks
regarding welfare ricks: 1) evaluate Appendix IV Of the Unfinished
Business Report (EPA, !SS7e) entitled "Welfare Risk Work Group"?
2} develop a welfare rick 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 tine frane nay 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 wist be modified to resolve this
discontinuity*
5*2
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 five 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
environmental problems.
The Subcommittee began the welfare ranking evaluation by
redefining welfare effects to be §11 f****5** °» humana and
societies, excluding human hmm1th effects, that aa¥ r«Sttlt froffi
28
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environmental .problems . Thus, welfare risk was expanded to include
all aspects of the quality of town life as interacting with the
environment. These welfare affects nay be indirect or dir«ct.
Indirect welfare effects include those effects Mediated by
ecological systems i i.e., effects on humans caused by changes to
the natural environment. These ecologically-mediated effects Bay
be further divided into impacts that involve irreversible
alterations to the environment, and therefore, fundamentally affect
resource attainability (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.
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
« few of the services produced by ecosystems, end ignored the more
complex and long-term interconnectedness of ell living things on
earth. It is imperative that the Agency adopt a broader end more
inclusive view of ecosystem services end work to integrate this
view with economic analyses of environmental problems.
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5.2.2
It has long been recognized that short-term profit
maximization i* a misguided objective. Economic analyses of
environmental issues Bust take a long-term view with the ultimate
goal of sustaining life supporting ecosystem functions. In the
long run, irreversible resource damage vill 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 lover 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
p«r year is inconsistent with the "stewardship responsibilities"
(page 6-10, EPA, 198?c) 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 sguity 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 tiore than an economic
problem. We need to address the scientific and ethical issues
associated with "sustainable11 social activity. For inter-
generational issues it nay be appropriate to adopt a cero discount
rate.
Moreover, discounting future environmental problems greatly
devalues the inportance of large-scale and long-term environmental
problems. Ecological systems have intrinsic time legs, such that
the adverse response from * stress is delayed to the future. This
is a basic characteristic of ecosystems that Bust 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 • Bedium level problem because
the effects would not be felt until the middle of the next century.
y«t desirable and effective control and mitigation activities for
climate change effects Bust begin much sooner, because of the
inherent time lags in global responses. The costs of .mitigation
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are usually not constant over time,.often increasing geometrically
because of the spa'Cfai dimensionality of the transport mechanisms.
Finally! the applications of discount rate* .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 substitutabl* for other
forms of capital, and should not be discouraged as if they could
be bought or sold like machinery or housing.
s.t.3 Willingness to lair
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
net reflect the ecological importance of natural systems and the
service* they provide to humans.
Zn addition, value criteria nay be problematic. The use of
willingness to pay implies that values assigned by en Individual
are constrained by tils or her affluence* This may be inconsistent
with property rights vested in public trusteeship and with public
right* of access to unimpaired natural resources reflected in
Federal statutes! An Environmental Bill of Rights.
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The basic ''services'* provided by the eeosystejo, 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 overexplcitation. 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 unjfcil the right to access frs removed or seriously
threatened. This is true in general for scarce resources, but
presents a severe problem for environmental Issues. Bv the point
in t^roe at... vhicfr this is realigned, it may be too 3,ate 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 such
greater than to maintain an unthreatened one.
5.1.4 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 utilised on the development
side of the analysis, they lujgj be utilized on the environmental
side a« veil. 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 chops,
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 olV-jjajor centroI^iiQd.T- mitigation efforts trould more
often exceed the costs of program 'implementation, ~
5*3 Welfare Kit* Paradigm
we propose an alternative velfare impact classification *chene
that is intellectually consistent with ecological function* and
time scales. As defined above, the specific velfare impacts fall
into four classes;
a) Ecological quality
b) Resource sustainability
c) Direct effects - economic
d) Direct effects - non-economic
These a*e discussed in further detail below (See also Table IX,
page 3 } ,
5.3.1 EfijaLoMeal Qua 1 i t y
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 Dot 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 prohibit* the
cale 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 bird*, sea otter*, and intertidal
organisms. But this i* 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
perturbation* of the ecosystem structure and function characterize
this category.
S.3.S Besoyypee attainability
This category of velfare impact* involve irreversible losses
of ecosystem structure and function*. 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-i radiation from a
depleted stratospheric ozone layer could reduce algal productivity
in marine ecosystems.
S.3.3 Direct effect* - Economic*
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 - If on-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. Odor* from animal feedlots, reduced
visibility in certain urban areas, and noise from truck traffic on
expressways are documented examples of these social perceptions.
1.4
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 acoiogically-aediated 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 issiies ^involves iipicts : on the environment that are
irreversible or of long duration compared to human perspectives.
The subcommittee considered tine to recovery ac an explicit
component of the rankings which are presented in Table XX (»ee 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* lie agreed that negative
impacts associated with sensory sodalities (sound, sight, or smell)
should be included. He 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 XX (see
page 36)*
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Table XI - Integrated Welfare Rankings*
RANKING
WELFARE ISSUE
RECOVERY TIME
HIGH:
Global Climate
UV-B Ozone Depiction
Habitat Alteration
Biologic Endangered/Extinct
L
L
L
L
MEDIUM:
Acid Deposition
Airborn* 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)
Radtonuelides
Chlorinatlon
Thermal Pollution
IN SOME
CASES,
HIGH RISK;
Deliberate Release of Genetic
Engineered Organisms
Introduced Species
* For Categories I, II, IV - Based on non-direct economic Issues
Recovery Time Is given as long-term, or centuries (U*. medium-term,
or decades (M); or short-term, or years (S).
3i
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i.O PIEATIS OH RISK
The Subcommittee reviewed the original EPA J.i*t of
environmental problems (Table III, see page 10)) with the foul of
modifying the list if, in our view, the list was either Incomplete
or duplicative from an ecological risk perspective, fie 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, vhich dealt vith 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 veil as species
extinction. Introduction of species was also added to the list,
on the basis that exotic species say disrupt natural communities
and ecosystems.
The Subcommittee reviewed the Background Papers written by
EPA in IS 17 and reevaluated the* in light of »ore recent
information. These background paper* were prepared by 1PA in order
to provide additional insight* concerning the environmental problem
areas. These were included in Appendix XIX of Unfinished Business
(EPA, 1987b). The following sections reflect the Subcommittee
discussion of these environmental problem areas. EPA summarized
37
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its ranking of environmental problems areas into mix groups, with
Group 1 problems having the highest Impact and Group i 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; H « Medium Risk; and L - Low Risk,
i.i Crit+ri* and Toxic Air Pollutants
The ecological impacts of ozone and acid deposition arc well
documented, and significant data bases en both the extent of ozone
levels and acid deposition now exist (HAS, 1989; KAPAP, 1989; EPA,
1988). Th* overview of ozone and acid deposition provided in EPA
(1987b) is detailed and represents a reasonable summary of the
state of the art in 19S6. Since then there have been a number of
studies (e.g., NAPAP, 1987) that have suggested that hydrogen
peroxide is also an oxidant that nay 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 «ir 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 toe 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 texie air pollutant* were ranked by EPA ae Group 4,
some chlorinated hydrocarbons play an important role in atmospheric
photochemistry. Thus, while one can argue that the important
direct ecological «tres«e« are otone 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 welT'ai' visibility-Induction. Sinc*;«o'lar'radiation
is an important factor that affacts 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 vith the seal* considered.
At ecosystem and regional levels, airborne toxics are high (KH)
risk, but at the biosphere level, that risk drops to medium (H).
Acid deposition is ranked at high (H) risk at both ecosystem and
regional levels,
6,2 Radiation from Sources Other tbtn 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 im AIARA
(as low as reasonably achievable) for high-level wastes, oftentimes
veil 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 th* environment* Anthropogenic
environmental exposures primarily result from residual weapons
testing fallout and industrial releases (including wtdical vast**}.
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 * well-developed
historic (and aging) literature with a we11-developed risk
methodology, and extensive standards development and regulatory
oversight. Environmental transport mechanisms and pathway* ar*
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known; biological/ecological Affects are organismally based.
Current public concern is ov«r 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, vith relatively low
uncertainty and number of unknown*. Thus, we disagree vith
Unfinished Busjj^ss statements of uncertainty for ionizing
radiations. Non-ionizing uv-B radiations ere 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 lov ecological risk ranking
is appropriate.
6.3 StratosphericOtene 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. Zt 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 nil CFC production in the next lew decades (Wigley,
1988). Consequently, projection* of future CFC emissions would be
reduced from projections Bade three years ego (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 «ven if all emissions were to cease
immediately (Lashof and Tirpak, i§89; Smith and Tirpak, 19S9).
Over the past three years, there i» also an improved
understanding of the atmospheric chemistry of CPC-stratospheric
ozone interactions. For instance, the experience of the very large
stratospheric ozone depletion event over Antarctica in 198? and,
1989 has shown how cfCs, interacting vith stratospheric ice
crystals and vith sunlight as it first reaches the stratosphere in
the austral spring, can very rapidly deplete stratospheric ozone
(Stolarski, 1988; Rowland, 1918; Shea, 1.989). This ozone-hole
phenomenon did not appear in the earlier models of atmospheric
chemistry, but has now been seen as veil over the Arctic.
Furthermore, estimations of columnar ozone depletion over the last
15 years or so now exceed 51 for northern mid-latitudes, somevhat
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 GFC'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
vith 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 (Horrest, 198S)*
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 (Horrest, 1985? Hoffman, 1987). Hovever,
experimental data on UV-B effects on most terrestrial plants arc
lacking; for example, how enhanced UV-B vould Affect the trees in
* tropical rain forest is essentially unknown. JFor crop plants,
about 200 eultivars have been tested, for which about one-third ar*
insensitive, and another third very sensitive, tout experiments have
not been conducted for many important crops (e.g., vork has been
done on only a very limited number of eultivars of rice). Thus,
assessing the potential biological consequences of increased UV-B
is difficult at present, although a research of fort to obtain tiv-
B dose response data for plants of ecological or agricultural
importance would reduce those uncertainties readily and vith
limited expense,
41
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secondary and indirect effects of increased UV-B are poorly
known? examples of potential Indirect effect* include increased
susceptibility to disease or pests by terrestrial plants.
Similarly, little is known about, interactions of enhanced UV-B with
other concurrent stresses, »uch as water stress iron 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* He 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 ecosystem* and
agricultural systems will be exposedi 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-Bi and 5) it nay 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 c^pift* 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 tine frames (Bolin et *!.,
I9S6). The EPA issue *CO2 and global warming" (problem area 8) is
more properly labeled "issues of global climate change", because
COj 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 United to warming (e.g., changes in
precipitation often May be more important than changes in
temperature). ^ , •,..„,
Anthropogenic sources of radiatively important gases include
CO2, primarily from combustion of fossil fuels, tout also from
deforestation and cement production? Q^, primarily from
agricultural production, especially from livestock and in rice
paddies; NfO, primarily from agricultural releases, *sp«cialiy from
42
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bacterial action on fertilizers; and CFCs, the same compounds of
central concern to «trato«pheric ozone depletion- (Keeling et al.»
1982; Bolin et al., 19S6; loll* et al., 1986? Mshof and firpak,
1989; Smith «nd Tirpak, 1989). Insofar as CFC emissions are
limited for ozone-depletion reasons, this will make a significant
difference to the eventual magnitudes and rate* of climate change
over the Jicxt several decades (Wigley, 1988). On the other hand,
even with complete elimination of CFC*, C02 production globally
vill 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 C02 atmosphere (i.e., vith total radiatively
important gas concentrations increased to the level equivalent to
doubling of CQ2 if that were the only radiatively Important fas)
(HAS (1979, 1983, 1987); Smith and Tirpak (1989); Bolin et al.
(1986); MacCracken and Luther (1985)). While these numbers are
useful for comparison* 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 effect* perspective* I**ues of spatial and temporal
scale are critical, as are issues of changes in the frequency,
intensity, or duration of extreme event* (as opposed simply to
changes in averages). that is, what will have most importance to
causing biological affects will be climatic: extreme*, 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
vill occur at local and regional scales end must be evaluated at
that scale (Harwell et al., U8Sa).
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 lest few decades for the entire
planet, but not for the United state*, for example) (Hanaen 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
43
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(e.g., Kerr, 1989). Nevertheless, that climate change win 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 projection*. How general circulation
models treat cloud formation, atmospheric-ocean interaction*, and
biological feedbacks (e.g., changes in rates of biogenic fas
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; Brseeker,
19»7) .
On the biological effect* 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 aany 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 - l.o meter by the middle of the next century, from thermal
expansion of the oceans (Smith and Tirpak, 1989; Lashof and Tirpak,
19S9)« 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 change* in the physical
environment with crop productivity es well *s ecxwyatem
distribution. Available methods Include historical analogs (e.g.,
Stomm*! end Stommel, 1979); statistical models (e.g., Uchijima,
If81}I physiological experiments (e.g., Uchijima, 1982); life tone
Classifications (e.g., Emanuel et el., 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 lie 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 eat,imatcd froa p«l«o«coiogical -analogs and toy
examining bioclinatie life zone shifts, with associated changes in
the distributions of biooes. 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*
f.S Direct and Indirect Point touree Discharge* to iqyfa.ce Waters
Direct and indirect point source discharges commonly refer to
the discharge of pollutant* 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, MPDES) that allows release of both conventional and toxic
pollutants at specified level*. Discharger* are clustered in the
eastern and midwest regions, where human and industrial activities
dependent on aquatic resources are most dense (EPA, 2.§§7b) * Many
industrial operations contribute to the load reaching municipal
wast* treatment facilities, and therefor*, ere indirect dischargers
to aquatic systems. Waste treatment facilities discharge vainly
to rivers (except in coastal tones) 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 (Ssj , and nutrients (P in
freshwatere; 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-tre«t»ent 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.
Me 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,
f.f Non-Point Sourfff^^f cftaEgf f_t9 jBurface .Waters gins tn-Plaee
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), groundwatsr -transport, mtaospherlc
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
loeal 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;
chip traffic; continued inputs) for decades and longer. Examples
of areas where in-place pollutants are a particular problem are Mew
Bedford Harbor, Waukegon Harbor, Fox River/Green Bay, Toronto
Harbor, Los Angeles Sight, 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, sore 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 title 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 * Group 3 or high
ranking. For the special ease 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.
§ »7 Cop ^ negated sludge
Sludge is one of the residual* or products from pollution
control or treatment systems. Since these systems are designed to
prevent hazardous substances and/or pathogenic organisms from
reaching the environment, it is not surprising that sludge is
usually contaminated. Sludge also can be generated by various
industrial processes, but industrial sludges are nore appropriately
covered by other sections and are not considered here.
Based on the data available, the authors of the EPA support
document concluded that, ". . .disposal of contaminated sludge should
not be expected to result in extensive damage to natural ecosystems
where reasonable anticipated control programs are properly
implemented" (Appendix III, Page 5i) . They further concluded that
damage would likely occur if control programs were not carried out.
The implicit assumption is that "reasonably anticipated control
programs" were designed with knowledge and understanding of all (or
most) of the hazard and exposure aspects of studies. Recent data
indicate that there have been important omissions, e.g., the recent
attention being given to the hazards of municipal solid waste
incineration ash.
The Unfinished Business document supports the premise that
there are a number of unknowns and uncertainties related to the
potential environmental impact of sludges. Among these is the
contention that information is available for only some of the many
different chemical pollutants and pathogens associated with sludge.
In addition, it Is stated that only limited efforts have been
expended on in-field documentation of ecological Impacts of
sludges, the assumption that current and "reasonably anticipated
control programs11 will minimi re environmental impacts is not
supported by the document.
The massive quantities of sludge presently being generated,
the wide array of sludge contaminants, and the projected increases
in sludge generation, necessitate that current and anticipated
sludge regulations be as effective mm possible in order to minimize
ecological impacts.
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The Subcommittee agrees with-"the''basic risk ranking for sludge
of low to median, depending on the area being exposed. Localized
impact can be much greater (e.g., the 12 Kile Dump Site), but
relative to such issues as global climate change, it does not
warrant a high ranking,
C,i Physical Alteration efAguatiepabltafcf
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 Iocs
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 network*} should not provide support In coastal
areas characterized by tidal marshes and coastal estuarie*. Local
zoning ordinances cannot torn expected to protect priority aquatic
habitats once the infrastructure is constructed. commercial
fisheries operations using throw nets or trawl* physically impact
benthic habitats. These activities should be restricted from
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critical areas. Animal grating needs to be regulated on riverine
communities along river*, streams, and pocket wetlands.
A viable aquatic habitat includes a diverse and productive
terrestrial community adjacent to the land-water boundary.
Sedimentation control i» 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.
«.t Active Hazardous iraptf gjtea
The Unfinished Business report ranks active hazardous waste
cites 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 cheaical/physieal/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 trill be veil designed, constructed, and
managed. Environmental releases of vapors to "Che atmosphere end
leachates to the surface and groundwaters ere expected to be low,
and the effects limited to local impacts. These ere the same
assumptions that were made for the lest generation of permitted
hazardous waste sites with obvious shortcomings. These sites were
permitted by State end Federal agencies with tile 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 veil 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 tvo
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 net
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 reguires far more than 10 years.
He recommend that this category be given the same rank (i.*.
Group 5) as the other toxic waste stream categories instead of the
Group 6 ranking given to it in Unfinished Business.
f.10 InaetJTe Hay >rdou« Wasfe Bites
Past disposal practices for hazardous waste often met legal
requirements at the time, but the resulting contaminated soils end
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
51
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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,e),
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 is most frequently observed chemicals as TGE, 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, 19S7). 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 much that natural resource
damage awards are likely to be sought under CERCLA (EPA, l«S7a,b).
There could be significant ecological impacts If toxic and
persistent chemicals (e.g., PCBs) contaminate sedi»*ntm 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
52
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unless something is done to decrease the amount; of waste (Nelzon-
Horehler, 1988). y • -v '
EPA placed this category in Group 5. The Subcommittee
currently ranks the ecological risk from inactive hazardous vast*
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.
«.ll Municipal and Industrial Kon-Ha»>rdou«..Jflltl _ftltff
* -jjj
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
r biota as well as human health.
'i •
- •'• Inputs to municipal waste sites include paper, yard wastes,
1 - food, plastics, metals, glass, textiles, wood, and a miscellaneous
category that can include chlorinated organic* (e.g., from cleaning
fluids) and aromatics (e.g., from paints and household products).
(Webster, 1988; Franklin Associates, 1988). Releases from these
landfills nay vary, but Wood and Porter (1986) identified 77
chemicals known to be released from municipal vaste landfills,
including methane, benzene, toluene, vinyl chloride, trichloro-
ethylene, and nethylethylketone.
Industrial non-hazardous vaste sites usually contain
substances specific to a particular operation and may be located
on an industrial facility site or at * 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 vast** (Huddleston *t *!*,
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,
(1188) cit* 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 l_f__ Initial Adjustment - This stag* 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 month*.
Stage.:i=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.
_ 4. Methane Fennentftion - The Intermediate products
formed in stage 3 are converted to methane and C02. 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. FinaJ. Maturation - Microbial action is limited due
to decreased availability of nutrients. Gas production ceases and
oxygen and oxidized species slowly reappear. Compounds resistant
to mierobial digestion are converted to humic-like substances
capable of completing 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 aromatic*
from municipal wastes ere 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 risk* 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-tern nature of the releases and the number
of and distribution of sites, however, warrant continuing
attention to this issue.
t.12
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., Jroad construction) can
result In shifts in diversity and abundance of natural populations,
but may allow survival of the ecosystems. Habitat disturbance stay
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 i» major, and for the most part, results in
irreversible Iocs of natural ecosystems, including species
extinctions.
Every effort should be Bade to preserve native ecosystem* 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 field*, and
low-density housing. These projects should be planned vith 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 us a local, regional, and global problem of
increasing importance vith high cumulative impacts and, therefore,
high ecological risks.
(.13 Accidental Eeleaaes ef Topics
Over 2,000 accidental releases of toxicants occur annually
Involving some 40 million pounds of the total. Only 2,4% of the
•vents release 90% of the total amounts of toxicants. Most of
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these cone 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 nonpersistant
organics like TCE and DCS. Given the above, the low risk ranking
is appropriate.
6.14 Oil BPilla
On average about 11 Billion gallons of oil are spilled each
year; <50% of this amount is spilled into marine environments and
40% in inland environments. Approximately 49% of all oil spilled
is crude oil, 30% diesel and other fuel oils, and the remaining 30%
other products (IPA, 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 196? and the
Santa Barbara spill in 1969 (e.g., API, IPA, 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 (HRC, 1985). This is likely to be the
ease for most population* affected by the large 1989 Exxon Valdez
spill in Prince William Sound, Alaska, as veil (Baker et al*,
1990). The exceptions to this are spills that enter low-energy
habitats where oil penetrates the sediments and Bay remain for long
periods. For example, oil spills kill adult mangrove trees, zt
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 *
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
•team cleaning to remove oil from rock*). We recommend that the
overall goal of spill response* should be to ainiaize the
ecological impacts of spills end 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, 1S84).
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 veil 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.
C.1S Underground Storage flanJEf
It has been estimated that from 10% to 251 of the underground
storage tanks (USTs) in use currently ere 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 VST 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
Si
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to the owner of th« site. In cases where a family business is th*
responsible party /"the costs of puch remediation nay result in
cassation 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, development* in biotechnology
currently available for bioremediation should be considered and
evaluated to minimise the cost of remediation if prescribed*
Zn general, the ecological risk from leaking USTs im 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. He agree with the ranking of Group 6.
% ; - ,.,
•£•!• orouadifater
Groundwater contamination is perceived by the public to be a
major class of environmental intuits. 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 van based on the
assumption that ecological impacts can only occur when groundwater
discharges to the surface. The filtering properties of *oil 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 front 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 veils, land
applications, material stockpiles, pipelines, and non-point
sources). Groundwater is generally slow moving and very
conservative in transformation functions. There ere 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.
C.3.7 Pesticide*
' i. S:iJ* \ .' 3? »'.".' . Jii.
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 ha* 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(sf leveling off at a little over
one billion pounds of active ingredient since the Aid* to late-
1970s. in fact, the amount of active ingredient used in the United
States in 1938 vas 1*13 billion pounds, about the sane mm 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.
He are also concerned by th« 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.
i.it New Tezie chemicals CMon-Pestieidesi
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 EFA'c
Office of foxie Substances since 1979, Many do not nave adequate
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ecotoxieity data for a "reasoned ecological risX assessment", the
criterion specified in TSCA.
To compensate, in part, for the lack of time and resources to
conduct laboratory toxieity assessments, models hav* been developed
to estimate a variety of parameters, including bioconeentration,
toxicity, and persistence. Quantitative structure activity
relationship (QSAR) models are example*, 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.
**** 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 Banner 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 say 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."
' Re comb i riant DNA technology allows the potential for complete
description of altered homogenetic or heterogenetie hereditary
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material that might b« included in the deliberate construction of
biological materials with altered properties. Therefore, risk can
be minimized, if not excluded, front 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 canter en the production
of plant life with altered characteristics. Here, as above, there
is a concern for the possibility that such plants night become
dominant to other beneficial lifa forms in a biological community
and, thus, hav« long-term detrimental consequences. However, such
concerns are also inherent to strain improvements accomplished
through traditional plant breeding technology. In the cast of
biotechnology products and the recombinant DNA technology used for
their development, however, the biotechnology-derived product* 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 concern* 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 ar* 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 sourest 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 en 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 th* content end usage of biotechnology
products. In some cases, this may require the development of new
regulatory purviews since these products lacX precedent end,
therefore, are inappropriate for some existing regulatory policies,
€4
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Regulatory agencies in place should take a proactive tola toward
facilitating biotechnology developments by working in concert with
the developers of this technology and the end-users. A case-by-
case policy teems appropriate currently until experience with th«*e
products i* acquired.
The potential risk for biotechnology relates directly to the
product* Since products with disparate properties and intended
usage are being developed , it doe* 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
mierobial species, it has been .suggested that genetic alterations
resulting in the loss of virulence, but maintenance of colonizing
activity by pathogens, night 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 night introduce new, and possibly more virulent traits, into
an altered microorganism that has retained its colonising activity
toward a target plant (s). Products beyond the foregoing
relationships, however, are likely to rank 'Ion 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*
§.28 Plastic in the Marine
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 i toxleity via ingest ion; and mortalities from
entrapment and entanglement. The magnitude of the aesthetic
problem Is relatively easily quantifiable. The number of
mortalities from Ingest Ion, 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.
Impact* can be severe for organisms that are particularly
pron« to ingest plastics. S«a turtle* are an important example.
Individual* of these endangered species have been ehovn to eat
plastics, and deaths have been attributed to much 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.
C.21 Biological D«pl«tion andExtinctions
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 i* loss or disturbance of natural habitats.
Over-harvesting 1m 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, Mien species become
threatened or endangered or natural populations are greatly
depletedi 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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(.22 Introduction of Biologic EpeciiJi
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 anthropogeniely 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 lov when the
recipient community is not stressed. Propagules and transient
individuals are constantly testing the system to look for nev
opportunities to expand their species domain. The resistance to
intruders cones 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 ease 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 ftost 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 vith little evidence
of serious ecological impacts, such as the plantings of brown trout
in rivers end lakes throughout the United States. The vide array
of ecological responses to the introductions of exotic species
requires that each event be given careful •valuation prior to
implementation. Since introductions, if successful, are usually
irreversible, proactive evaluations should be mandatory.
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RECOMMENDATIOKfl AKD CONCLOSTOKfl
1. Formalin an extramural and continuous process for ecological
risk prioritiiationi thl* process should not be categorise* If
agency programmatic structure but ra%ner by anthropogenic stresses
on tna environment*
The 19S7 "Unfinished Business" report represented a pioneering
effort in assessing the relative risks of environmental *tressors
and their prioriteration 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 veil 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. Inveit i& development of formal methodologies for ecological
risk assessment.
Although the ecological and welfare rick ranking procedures
used in our deliberations were a useful tool, these ad hoc
procedures represent only a beginning in quantifying and
formalizing risk prioritizatlon. The process remain* 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 control* and corrective action*} needs
to be expanded to include proactive and anticipatory alternative*,
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..date bat** seeded for improving future ecological
risk assessments.
Ecological risk assessment IK handicapped by the availability
of organiied sets of comparable quantitative data to support the
risk evaluation process, the science it»elf lack* neither
concepts or data, but is deficient in systenatle 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 end 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 aad
economic perspective* and con»ider»tion*.
*
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 tents, 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. Mot until ecological and
economic values of environmental systems can be unified will it be
possible to obtain unbiased assessments of ecological worth,
accurately to prioritise stressors and systems at risk, and to
begin cost-effective strategies for risk reduction.
5. Expand IPX's perspective on ecological values «*& welfare -risk
to include ecological attributes a* veil as economic factors*
In developing an integrated ecological/economic paradigm for
environmental risk assessments, it vill be extremely important* to
address those many ecological attributes for which an economic
metric presently does not exist. The costs ef remediation greatly
exceed expenditures to ensure early prevention of ecological
damage. To address the cost/benefit ef environmental actions,
entirely new concepts of ecological attributes as finite resources
6$
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a:,c compounding rather than discounting when choosing alternatives
to environmental protection will be necessary,
6. incorporate the results from tbi» risk ranking process,
including tb« 1»90 risk reduction study, in development pf future
Agency policy Had allocation of financial resources.
The 196? "Unfinished Business" report and this 1990 risk
reduction exercise by the KRRSc 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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