Current practices in the use of risk assessment in regulatory
programs vary among Federal agencies and even among regulatory
programs within the Environmental Protection Agency (EPA). Some
of the variation is attributable to different requirements among
federal laws authorizing regulatory activity, either in the form
of explicit methodologic requirements that assessments must
follow or as differently mandated regulatory responsibilities
that the assessments must support. And some of the variation
reflects differences in policy among organizations, adopted as a
matter of differing scientific and policy judgment or simply
because of the independent establishment of varied precedents and
preferences. Better coordination among agencies is needed, and
there have been several calls for a central organization to
coordinate all risk-assessment activities.
Previous sections of this report have addressed the larger
risk-assessment and risk-management issues that affect
environmental, health, and safety regulatory programs across the
federal government. This section narrows those general issues and
recommendations to individual agencies and programs and uses them
as a basis for specific recommendations. This section is not
meant to be an exhaustive evaluation of all the federal agencies
that assess and manage risks, but to highlight those that
provided testimony to the Commission.
FINDING 6.1: Risk-assessment practices are
poorly coordinated among and often within regulatory agencies and
programs, even among those with overlapping interests and
jurisdictions. Inconsistencies and idiosyncratic practices impair
the credibility of risk assessment.
RECOMMENDATION: When two or more agencies or
program offices regulate similar health or ecological hazards
associated with chronic exposures, they should coordinate their
risk-assessment methods and assumptions, unless there is a
specific statutory requirement for different choices or a
scientific disagreement, which should be explicated.
RATIONALE
The primary reason for differences among agencies in
performing risk assessments is that the function of the
risk-assessment process--to project possible human health risks
associated with the various types and magnitudes of exposures
that might arise--outstrips the ability of scientific
investigation to give firm answers. The practical need remains to
characterize the risk consequences (including the uncertainty
about them) of various potential actions and activities by
industries, by government, by individuals, and by society as a
whole.
There is general agreement on a common framework and structure
for risk assessment, but debate continues vigorously about the
most-appropriate risk-assessment approaches, the bearing of
various kinds of data on risk projections, the level of risk that
is considered negligible, and the degree and appropriateness of
conservatism in risk-assessment methods. The effect of the
diversity of methods among federal regulatory agencies is to make
it difficult to compare risks, or the actions taken to mitigate
those risks, from one regulatory program to another. For example,
EPA and the Consumer Product Safety Commission (CPSC) differ on
several critical aspects in the performance of a quantitative
risk assessment, including reliance on the "maximally
exposed individual" or other upper-end exposure estimates at
EPA versus the average population exposure at CPSC and the use of
upper-bound risk estimates at EPA versus maximal-likelihood
estimates at CPSC. EPA occasionally uses pharmacokinetic
information for cross-species extrapolation, but CPSC has
declined to do so.
Although defaults and standard methods are necessary in the
face of uncertainty and lack of case-specific knowledge,
variation among agencies and programs increases the sense of
arbitrariness in risk analyses. In cases where regulatory
responsibilities overlap or different groups have cause to assess
the same exposures, differences in assessment outcome can lead to
conflict and confusion among the public and the regulated
community. When inconsistencies exist among agencies with
overlapping regulatory responsibilities, a continuing effort is
needed to harmonize methods and assumptions used in risk
assessment. In cases where consistency is inappropriate, written
justification should be provided. Lorenz Rhomberg's report to the
Commission details the use of risk assessment by federal agencies
and indicates where some of the inconsistencies exist (see
appendix A.6).
EPA has played a critical role in facilitating the substantial
improvements in our environment that we have enjoyed over the
last 25 years. The major sources of pollution contaminating our
air, water, and soil have been greatly mitigated, largely as a
result of its efforts. The complex and intransigent problems that
remain will require continued creativity and, in some cases,
improved efficiency. This section addresses several of EPA's
programs and offers recommendations that are aimed at improving
the identification and management of risks.
The Clean Air Act Amendments of 1990 contain several
provisions of particular relevance to the Commission concerning
the assessment and control of criteria air pollutants (section
109) and hazardous air pollutants (section 112). The same sources
often contribute pollutants of both types. For example, motor
vehicles are major contributors of the criteria air pollutants
ozone, carbon monoxide, and particles, and they are also the
source of about one-third of all hazardous air pollutants,
including benzene, 1,3-butadiene, and formaldehyde. Similarly,
point sources, especially those which use large quantities of
volatile organic compounds, contribute to both the regional ozone
air-pollution problem and increased concentrations of hazardous
air pollutants in the local environment.
The 1990 amendments to section 112 established an entirely new
program to control hazardous air pollutants from point sources
through the promulgation and implementation of technology-based
standards embodied in what is known as maximum available control
technology (MACT). Congress required that the need for further
control be determined through risk-based approaches after
implementation of MACT. The MACT strategy was mandated because
the regulation of hazardous air pollution from point sources with
a purely risk-based approach seemed to be ineffective and
inefficient. Difficulty in setting new standards was attributed
to "paralysis by analysis", according to the National
Resources Defense Council's David Hawkins, who was assistant
administrator for the Office of Air and Radiation under President
Carter. Although most air pollution had been regulated, there had
been relatively little impact on the tonnage of pollutants
released into the air, as was evident from Toxic Release
Inventory data. It is not known whether a technology-based
approach will be more effective in protecting public health than
a risk-based approach.
As of May 1996, EPA had promulgated 27 MACT standards
(including 10 in the overall category of hazardous volatile
organic chemicals) and had proposed four more; a total of 174
source categories need one or more MACTs each. Full MACT
implementation is projected by EPA to cost about $600 million per
year and to reduce hazardous air-pollutant emissions by 880,000
tons and criteria air-pollutant emissions by 1,900,000 tons per
year.
The risks that will remain after MACT standards are in place
(residual risks) have not yet been determined. Preliminary
analyses are being conducted at EPA. The agency is applying a
case-study approach to assess data availability and to evaluate
screening methods and models that might be used in the
residual-risk program. Criteria that will be used to choose
screens include ease of use (so that "nonexperts" can
conduct screening assessments) and extent of conservatism. The
goal is to find a method or methods that will eliminate from
further analysis sources that are clearly of no concern and focus
attention on sources that need further, more-rigorous analysis.
One potential screening method is EPA's three-tiered analysis
described in appendix J of Science and Judgment in Risk
Assessment (EPA 1992d, NRC 1994a). Tier 1 is a conservative
screen that requires only stack heights, distances to fence
lines, emission rates, and "lookup tables" to obtain
maximal off-site concentrations. Tier 2 is also conservative,
adding to tier 1 data only some generalizations about stack
characteristics and a distinction between urban and rural
environments. EPA's preliminary evaluations using the tiered
approach demonstrate the enormous data gap that must be filled
even to perform screening analyses, much less estimate residual
risks reliably; there were enough data to evaluate only seven
source categories at tier 1 and for only two of those were there
enough data to proceed to tier 2.
This section presents recommendations regarding the assessment
of residual risks after MACT, as the Commission was mandated to
do by Congress, and addresses several other MACT-related issues.
We also address the topic of indoor air pollution.
FINDING 6.1.1.1: EPA needs and wants guidance
on how to implement the residual-risk provisions of the 1990
amendments to the Clean Air Act after controls have been put in
place to meet technology-based standards. The current Clean Air
Act requirements can be interpreted to imply that if even a
single facility within a source category is found to pose a
residual cancer risk of 10-6 or more after maximum
available control technology (MACT) has been implemented, EPA
must set new standards for the source category. That policy could
lead to devoting extensive resources to pollution controls where
there are no important risks.
RECOMMENDATION: To determine and manage
residual risk after implementation of MACT, the Commission
proposes a specific tiered scheme (see figure 6.1): characterize
and articulate the scope of the national, regional, and local
air-toxics problems and their public-health and environmental
contexts; obtain necessary data and perform screening-level risk
assessments to identify sources with the highest risks; conduct
more detailed risk assessments of sources and facilities with the
highest risks; evaluate risk-reduction options at facilities that
have incremental lifetime upper-bound cancer risks greater than
one in 100,000 persons exposed or, for noncancer risks,
concentrations greater than reference standards, using the
Commission's risk-management framework set forth in section 2;
and determine the need to evaluate residual risks from less
high-risk source categories. The scheme is described in detail
below.
1. Problem/Context Characterization. To provide
guidance for stakeholders and for implementing the residual
risk-assessment and risk-management scheme, the scope of the
local, regional, and national air-toxics and air-pollution
problems are characterized. The problems are put in context by
comparing air-toxics issues to air-pollution issues in general
and to other, multimedia sources of exposure to the same
chemicals. The goal is to build an understanding among
stakeholders about the health context of residual risks from
regulated point sources of emissions.
2. Screening Risk Assessments. Priority source
categories or subcategories are identified that the agency
considers likely to pose the highest residual risks. Screening
risk assessments of facilities are performed by source category
(or subcategory), starting with those which the agency has
identified. Screening risk assessments can follow methods such as
EPA's tier 1 or tier 2 procedures for assessing risks from
hazardous air pollutants (EPA 1992d, NRC 1994a). Screening risk
assessments must rely on many default assumptions and the
defaults must be realistic and chosen with care. The specific
methods, criteria, and assumptions for performing screening risk
assessments should be developed by EPA in partnership with state
environmental regulatory agencies, with appropriate peer review
and stakeholder input in an open and transparent process.
Successful implementation of screening risk assessments will
require more and better data than are now available to EPA. EPA
should establish a miminal data-quality requirement for
source-category emissions to be used in residual-risk assessments
and, where that requirement is not met, initiate a data-gathering
effort supported by states and regulated parties. Initial
data-collection efforts for screening assessments will need the
cooperation of states, and data collection for refined risk
assessments will require the cooperation of regulated parties.
Data should be gathered during MACT development through the
section 114 questionnaire and the information collection request,
when collaboration with regulated parties is already taking
place. Modifying Toxic Release Inventory reporting requirements
so that what is reported is more consistent with data needs
should be considered, such as reporting average emission rates,
not total emissions in pounds.
3. Detailed Risk Assessments. If source categories
considered in the screening risk-assessment phase are found to
pose an incremental lifetime cancer risk that exceeds 10-6
for a reasonable upper-bound-exposed person in an affected
population or if a noncancer hazard index--sum of the ratios of
exposure concentrations of noncarcinogens to their Reference
Concentrations (RfCs)--exceeds 10, the categories should be
further classified. Those values are proposed as potential bright
lines (see section 5.3), but some experience with source
categories will be needed to see how well they serve in forming
appropriate categories.
If a cancer risk is 
10-4
or a noncancer hazard index is 10,
the source category is considered to have high priority. More
detailed risk assessments should be performed first within that
category. Those risk assessments should be facility-specific and
should be performed in partnership with regulated parties and
other stakeholders as appropriate.
If a cancer risk is between 10-6 and 10-4
and a noncancer hazard index is less than 10, a source category
is considered to have less-high or "medium" priority.
Risk-assessment results should be distributed to the affected
industries and other interested parties so that voluntary process
changes or other actions can be evaluated to reduce emissions or
risks associated with those sources.
4. Risk Reduction. Additional controls or process
changes should be evaluated if more detailed risk assessments
performed within source categories found to have high priority
yield incremental lifetime cancer risks of 10-5 or noncancer hazard
indices of 1 to reduce them to
below 10-5 or 1, respectively. If the more detailed
risk assessments yield incremental lifetime cancer risks of <
10-5 and noncancer hazard indices of < 1, no
further action should be required. To the extent practical, when
more than one source category of high priority is found at the
same facility their risks should be evaluated together.
Identifying and implementing changes to reduce risk, where
required, should be performed as part of a local or regional
risk-management process conducted with the Commission's
framework. Establishing risk-management goals with that framework
should include consideration of not only the individual facility
of concern, but also its context, including pathways of exposure
to hazardous air pollutants besides inhalation (such as water or
soil), the air-quality characteristics of the region, other
sources of pollutant emissions, and considerations in addition to
human health risk such as costs, benefits, equity, and values.
The process must be conducted with full stakeholder
participation.
5. Iteration. On the basis of learning from the risk
assessments for the source categories considered by the agency to
pose the greatest risks, the agency should determine the need for
proceeding with assessments of medium-priority and low-priority
source categories.
RATIONALE
Several aspects of the preceding scheme require elaboration.
The Commission believes that EPA--through the experience
gained during the first stages of implementing the 1990
amendments to the Clean Air Act, developing MACT standards, and
setting priorities among hazardous air pollutants--has acquired
enough information to identify the source categories most likely
to pose residual risks. High-priority source categories should be
identifiable on the basis of quantitative information, such as
emissions data and how many people are exposed, where available,
and also on the basis of qualitative considerations, such as
whether high-priority hazardous air pollutants are present,
whether there are sensitive subpopulations, and whether there are
highly exposed populations, or "hot spots".
Figure 6.1 describes a process whereby priority is given to
sources likely to pose the highest risks. Subjecting source
categories to a priority ranking requires the development of a
screening risk-assessment model. Screening is based largely on
some consistently applied estimate of exposure. At each step in
the screening assesment, some decision must be made about the
priority to give the categories and what actions to take. The
Commission recommends integration of this screening process
within its framework for risk management described in section 2.
Performing screening risk assessments at every facility within
a source category would be prohibitive, so a screening model that
can be used to generalize risks for a source category or for
types of facilities within a source category is needed. The
screening model must be able both to account for differences
among facilities and to provide results that can be used as a
guide to making decisions about the need for further analysis.
EPA should develop useful screening methods in partnership with
state regulators and with input from regulated parties and other
stakeholders.
Upper-end point estimates of exposure can be appropriate for
screening risk assessments, but the use of the hypothetical
maximally exposed individual (MEI) yields such an unrealistic
overestimate of exposure that it should not be used (see section
3.2). Screening risk assessments should rely on
more-representative estimates of exposure, such as EPA's
"high-end exposure estimate" (HEEE) or an estimate
based on a highly exposed actual person or reasonable worst case.
More-detailed risk assessments should consider the entire
exposure distribution (see section 3.2).
The goal of a screening risk assessment is to ensure
protection of any especially susceptible subpopulations by using
conservative assumptions to estimate toxicity, such as cancer
potencies and RfCs. Detailed risk assessments should reflect the
multiple pathways by which exposure to hazardous air pollutants
can occur, obtain population- or ecosystem-specific exposure data
to the extent feasible, and consider in more detail the health
status of the community and specific population subgroups for
health effects of particular concern.
Within the decision-making framework, a threshold is needed to
discriminate between sources that should be considered further
and sources that need not. The Commission opposes the inflexible
use of bright lines for regulation, but using a bright line to
guide a decision-making process is necessary for efficient risk
management.
The 1990 amendments to the Clean Air Act set 10-6
as the threshold for considering source categories for reduction
of residual risk. Those with screening risk estimates that fall
within the 10-6-10-4 range might not
require high priority because of the conservative nature of the
assumptions used in screening risk assessments. The Commission
therefore recommends that an intermediate category of
"medium" priority be established for source categories
with estimated risks between 10-6 and 10-4
on the basis of screening assessment. Sources that fall within
that range might consider voluntary engineering improvements to
reduce emissions and risk. Using a flexible 10-6-10-4
approach is consistent with the permitting strategy already in
place in a number of states, according to testimony received by
the Commission from Joann Held and Tad Ahern, who manage air
toxics programs in New Jersey and Maryland, respectively, where
facilities within that range can negotiate their options.
The 1990 amendments do not set a threshold for considering
health risks other than cancer, which the Commission believes to
be a serious omission. We chose a threshold noncancer hazard
index of 10 because there are few hazardous air pollutants with
RfCs that are within a factor of 10 of their
no-observed-adverse-effect levels. A screening-level hazard index
is calculated by dividing the exposure concentration of each
noncarcinogen by its reference concentration (RfC) and then
adding those ratios together. Detailed risk assessments might
rely on several hazard indices, determined by adding together
ratios only for chemicals with similar health effects.
The Commission prefers a 10-5 flexible bright line
for actions to reduce residual cancer risk based on detailed risk
assessments. That action level is consistent with Congressional
guidance to use 10-6 for screening purposes. The
choice of that decision threshold will be better informed after
some experience is gained across source categories, including
replacement of default assumptions with actual exposure data. Use
of a threshold for action more stringent than a 10-5
lifetime upper-bound incremental cancer risk would continue an
outdated practice of giving much greater attention to cancer
risks than to all other health and ecological risks. In fact,
within the Clean Air Act, there is a striking contrast between
permissible margins of exposure for section 112 carcinogenic air
pollutants and ubiquitous section 109 criteria air pollutants.
For a lifetime upper-bound risk of 10-6, the
permissible margin of exposure for carcinogenic air pollutants is
greater than 100,000-fold. For lead, carbon monoxide, small
particles, and other criteria air pollutants, the permissible
margin of exposure of recognized susceptible populations is below
exposures associated with adverse effects by less than a factor
of 2.
Section 112 addresses other serious hazards besides cancer,
such as reproductive, developmental, and neurologic impairments.
California's Proposition 65 labeling regulations similarly cover
carcinogenic and reproductive effects. In that state,
environmental activists and businesses accepted an agency
decision to put the action level for carcinogens at 10-5
and the action level for reproductive toxicants at one thousandth
of the no-observed-adverse-effect level. Those action levels for
labeling apply to products to which very large numbers of people
are likely to be exposed. For many section 112 source categories,
in comparison, relatively few people are within exposure range of
the point sources. Expressing risks in terms of numbers of
persons who might be affected per year or per hypothetical
lifetime, as well as the probabilistic estimates per 100,000
persons exposed, can help in risk communication (see section
5.1).
Implementing a tiered or phased approach to assessing risk,
such as that recommended here and in Science and Judgment in
Risk Assessment (NRC 1994), could lead to awkward
public-relations circumstances. Situations might arise in which a
community is told that a nearby facility might present a
potential health risk, on the basis of a screening risk
assessment, and is then assured, after a more detailed risk
assessment, that the facility does not pose a threat. Members of
the community are likely to remain suspicious and believe that
the facility is hazardous despite messages to the contrary.
Communicating iterative estimates of risk to the public and the
media without loss of credibility is extremely difficult and will
require serious consideration in each case. EPA has a special
responsibility to communicate that the purpose of a screening
assessment is to separate sources that clearly pose negligible
risks from sources that might pose higher risks and that
screening assessments do not assess the magnitudes of likely
risks. Early and regular stakeholder participation might reduce
the likelihood of conflict; outrage often arises when affected
parties are brought into the process late (although there can be
additional interested parties at later stages).
When a facility is identified as having high priority and
posing potential risks to health, a participatory,
community-based approach to managing those risks should be used.
Involving stakeholders in the risk-management process described
in section 2 can identify additional factors that should be
addressed, improve the quality of risk assessment, and increase
the likelihood that the results of risk assessment and any
decisions made with regard to managing risks will receive broad
acceptance.
The Commission recommends that the risk-management framework
described in section 2 be used to guide the design and
implementation of strategies to address residual risks associated
with sources subject to MACT standards. A goal of this framework
is to involve stakeholders in the process early. As the process
becomes more and more specific to local situations, however, so
will the involvement of different stakeholder groups. For
example, in the early stages of the process, when procedures for
defining MACT subcategories and screening models are being
developed, stakeholders might include the regulatory agencies,
industries, and environmental or public-health organizations that
address national issues. During later stages of the process, when
the risks and risk-reduction options associated with individual
pollutant sources are being considered, stakeholders might
involve other participants from the community, such as
health-care providers, plant managers, local politicians, and
other citizens concerned about the outcome.
Problem/Context. Implementation of the decision tree
for evaluating the problem of residual risks should begin by
defining the scope of the national, regional, and local
air-toxics problem. The public-health and environmental contexts
include other sources of emissions of the same pollutants and
risks associated with other regulated--and not-yet
regulated--pollutants. The goal is to build a consistent
understanding among stakeholders about the health context in
which a particular pollution problem is being addressed and to
provide guidance for the rest of the decision tree.
Risks. Once the problem is defined, the next stage of
the process involves estimating the potential health risks
associated with source categories that have implemented MACT.
First, priorities are set among them. As of May 1996, 27 source
categories had MACT standards. However, their relative hazard
potential is largely unknown, and a process for identifying
potentially high-risk sources has not been articulated. Including
stakeholders at this stage might involve establishing basic
criteria for defining MACT subcategories and developing a
strategy for obtaining the necessary information to perform a
screening risk assessment. EPA could develop a draft plan and
make it available to the public through a variety of mechanisms
(e.g., dissemination through the Internet or through regional
offices, state air agencies, and state environmental and health
organization). Public dissemination could provide two benefits:
obtaining input to the draft criteria-development and
information-gathering strategy and identifying potential
stakeholders for future steps in the process. Indeed, EPA is
already working with state agencies to develop presumptive MACT
standards; thus, the groundwork has been laid for expanding this
effort during the stage of residual-risk determination in the
hazardous air-pollutant program.
The goal of performing screening assessments of the MACT
categories and subcategories is to determine whether they warrant
further attention. The basis for the screening assessment is a
screening model that relies on production, emissions,
meteorologic, and demographic data. Peer review is necessary to
ensure the integrity of the model among stakeholders. If the
process of identifying MACT subcategories has been effective,
there should be little disparity between the screening-model
findings and the results from individual facilities. However, if
a large number of sources have individual screening results that
are either much higher or much lower than source-category
screening model results, that could provide important
risk-management information.
For sources identified as having high priority, a local
stakeholder process would be set up--presumably from a subset of
previously identified stakeholders--as well as newly identified
participants. The stakeholder group would monitor the development
and results of the detailed risk-assessment process. The group
could provide useful input to the risk assessment and economic
analysis by posing specific questions for the analysts to
consider and by identifying exposure-assessment data needs and
potentially vulnerable subpopulations.
Options. As in the risk-assessment stage of the
framework, stakeholders could pose questions concerning economic
impacts and technical details associated with various alternative
options for pollution control or risk reduction. Care should be
taken to ensure that the quality of this information is
acceptable to the stakeholders, including use of peer review.
Decisions. Following the framework will not change the
decision-making responsibilities of the regulatory agencies.
However, the decision-making process should become better
informed, include more explicit information on the costs and
benefits of the actions chosen, and, if implemented properly,
gain more public support than decisions that are made without
stakeholder participation.
Actions. Traditionally, ensuring that actions are taken
has been the responsibility of the licensing and enforcement
divisions of regulatory agencies. Despite the importance of this
activity, public involvement is generally at its lowest at this
stage of the process. A solid oversight effort by stakeholders
could ensure that actions are taken in a timely manner and are
maintained and that implementation problems are properly
identified and addressed.
Evaluation. In general, although there is often much
criticism of risk-management decisions and actions, there is
little evaluation. For example, was a decision responsive to the
problem that was identified? Did the actions taken achieve the
intended results? What recommendations could be made for
addressing similar problems in the future? What were the critical
information needs or gaps? Were the benefit and cost estimates
reasonable?
It should be recognized that environmental risk management deals centrally with the need to make and implement decisions in the face of much uncertainty. If the overall process of risk management is to move forward, careful and thoughtful evaluation must take place. If done routinely and consistently, the results of such evaluations could provide valuable information concerning research needs and the development of better analytic methods, and could form the basis for improving the risk-management process as a whole.
FINDING 6.1.1.2: In carrying out its
hazardous-air-pollutant program, EPA has attempted a
decision-making mechanism that involves the regulated parties at
the very early stages of the process. This mechanism, referred to
as the MACT partnership program, is intended to optimize the
amount of knowledge, skills, and resources devoted to the
development of a MACT standard.
RECOMMENDATION: The partnership program
should continue and be expanded to facilitate a stakeholder-based
approach to setting MACT standards, including health and
environmental organizations and community representatives. should
establish an evaluation process for the partnership program. If
it is found to be useful and effective, the Commission further
recommends that it be used to facilitate decision-making related
to residual-risk determinations.
RATIONALE
The hazardous-air-pollutant provisions of the Clean Air Act
require EPA to promulgate standards for 174 source categories
over a clearly defined timetable. The goal of EPA's partnership
program is to reach decisions about MACT standards through a
consensus-based decision-making process. Participants in this
process hope that through a partnership framework, decisions can
be made in a more timely and effective manner than has occurred
thus far. At least points of disagreement could be identified and
reduced. The Commission was told that use of the partnership
program to facilitate decision-making shows promise in this
regard, although a formal evaluation of the program is lacking.
Conceptually, the partnership approach appears to be
preferable to other decision-making models. It is important to
determine whether the decision-making mechanism can be improved,
however, both to expedite the promulgation of standards and to
yield starting points for issues concerning residual-risk
determinations.
FINDING 6.1.1.3: Many emissions sources can
be subject to multiple MACT standards, as well as to additional
Clean Air Act provisions (such as those addressing ozone
control), so the impact of multiple regulatory requirements must
be considered.
RECOMMENDATION: EPA should continue its
efforts to integrate multiple permitting requirements into a
workable licensing system. In particular, it should consider
adopting some regulatory flexibility for sources with multiple
compliance schedules. This flexibility should focus on maximizing
the cost effectiveness of pollution-control measures within a
reasonable timeframe. It should also focus on the
pollution-reduction benefit that a more-comprehensive regulatory
program could achieve.
RATIONALE
Control of individual pollutants should not be considered in
the absence of an overall regulatory context. Because MACT
addresses existing sources, consideration should be given to the
effects of multiple control requirements on the systems operating
within a facility. Generic pollution standards for individual
processes might neglect how the processes interact with other
systems within a facility. They might also neglect the logistical
problems that can arise when particular processes are modified.
More-sophisticated policies for determining regulatory compliance
are needed to address pollution-control issues associated with
complex systems. Emphasis should be given to applying MACT
throughout a facility with control-technology requirements and
timelines set to optimize both the effectiveness and the
efficiency of pollution-reduction measures. The partnership
program should help facilitate an integrated approach.
FINDING 6.1.1.4: Compared with extensively
regulated outdoor air pollution, indoor air pollution can pose a
substantial risk to human health. Yet, it receives little
attention and remains largely unregulated. EPA's efforts to
address indoor air pollution reportedly have been thwarted by its
lack of statutory authority, by the lack of agreement on the
nature of the problem and its solutions, and by the fact that
jurisdiction over indoor air pollution is shared by several
regulatory agencies.
RECOMMENDATION: Congress should direct EPA,
OSHA, and other federal agencies to develop a coordinated
strategy that addresses the growing problem of indoor air
pollution. In developing this strategy, the agencies should
consider implementing the Commission's risk-management framework
as outlined in section 2 of this report. Until a coordinated
regulatory strategy that addresses the problem of indoor air
pollution is developed and implemented, EPA should continue to
encourage the formation of building and safety committees to
address indoor-air quality concerns.
RATIONALE
Over the last 2 decades, public-health attention has been
drawn increasingly to the problem of indoor air pollution. The
energy crises in the 1970s led to a lowering of fresh air
ventilation rates recommended by the American Society of Heating,
Refrigeration and Air Conditioning Engineers. Many building
owners responded by lowering the amount of fresh-air circulation
through buildings and adding insulation to the walls. Meanwhile,
increasing quantities of products containing volatile chemicals
were introduced into buildings, such as plywood and pressed-wood
products and carpeting. The National Institute for Occupational
Safety and Health (NIOSH) has reported many complaints, mainly of
nonspecific symptoms, such as headache, nausea, and eye
irritation. The lack of a clearly distinguishable constellation
of symptoms and their causes within indoor environments, led to
use of the term "sick building syndrome".
In addition, specific indoor-air pollution problems have been
identified or better appreciated over the last 2 decades. They
include effects of environmental tobacco smoke, radon, asbestos,
lead, and indoor allergens (e.g., mold and dust mites). Exposure
to those pollutants is associated with clearly defined health
effects, such as lung cancer and asthma. Legionellae and other
infectious agents can live in air-conditioning ducts and other
indoor, moist niches and cause outbreaks of infections, possibly
in combination with chemical exposures.
There is no risk-management framework for addressing
indoor-air pollution concerns. There are essentially no
enforceable standards, and EPA's regulatory attention is focused
mainly on outdoor air, despite research findings on total
exposures. The attention of the Occupational Safety and Health
Administration (OSHA) is focused mainly on industrial
environments. Meanwhile, problems in offices, public buildings,
and homes remain relatively unrecognized and unaddressed. Both
agencies recognize the growing importance of the problem, but
neither has the regulatory mandate to address it fully. There is
an interagency task force that has begun to address the problem
but it, too, lacks a statutory mandate.
Approaches to indoor-air pollution assessment and education
generally remain fragmented at both the federal and state levels.
EPA's Office on Radon and Indoor Air Quality provides educational
materials, and EPA coordinates indoor-air research efforts on an
intra-agency and interagency basis. NIOSH continues to be active
in surveillance. However, there is much political opposition to
the development of a regulatory program: a recent OSHA public
hearing on restricting smoking in the workplace and developing
basic ventilation requirements was strongly dominated by the
tobacco industry and various building-owner organizations.
Indoor air-quality problems are often complicated by their complexity and by their wide variation from one building to the next. Despite the differences, however, some guidance exists that can help to address these problems. EPA has produced excellent documents that can provide useful information. For example, the agency produced a kit called "tools for schools" that provides schools with much-needed assistance in addressing indoor air-quality problems. The agency could gain valuable risk-management expertise in this area as it provides technical assistance to building committees organized to address indoor air-quality concerns and conducts evaluations of the effectiveness of their activities.
When Congress enacted the original Superfund statute
(Comprehensive Environmental Response, Compensation, and
Liability Act, or CERCLA) in 1980, few were aware of the extent
of the problem created by years of inappropriate or inadequate
hazardous waste disposal practices. Many thought that the program
would need to clean up just a few hundred sites, and expected the
initial authorization of $1.6 billion plus reasonable
expenditures by private companies to be sufficient and the
cleanup to be quick. Today, we recognize that we must still
address several hundred thousand contaminated sites, a legacy of
an earlier industrial era. We also recognize that most of those
sites are not so highly contaminated or complex as to require the
attention and active management of the federal Superfund program.
EPA, states, and others are working together on a range of
approaches to address this wide array of contaminated sites. In
particular, there is greater focus on brownfields created by the
stigma of contamination that can be restored and employed in the
local economy. Many states now administer voluntary cleanup
programs that can efficiently return contaminated lands to
productive reuse. Nonetheless, the shadow of liability under the
Superfund statute hangs over all those sites.
Over the years, EPA has identified more than 40,000
potentially contaminated sites in its Comprehensive Environmental
Response, Compensation, and Liability (CERCLIS) database. After
site-specific evaluations, EPA recently announced that more than
27,000 of those need no further federal attention--a step that
should assist in removing them from the liability shadow. The
federal government and the states continue to study, design, and
carry out cleanups at the remaining 13,000 sites on the CERCLIS
data base. To date, about 1,300 of the 13,000 have been placed on
the National Priorities List (NPL) for federal attention, and
just over 25% of the 1,300 have been cleaned up. Although each of
the last 2 years has produced more completed cleanups than the
entire first decade of the program, progress is slow. With an
average cleanup cost of $30 million per site, it is also very
expensive. As Clean Sites Inc. President Toby Clark has testified
before Congress, usually someone is happy when Congress causes
billions of dollars to be spent; almost everyone, however, seems
disappointed with Superfund, for diverse reasons.
The 1990 amendments to the Superfund National Contingency Plan
(NCP) addressed the competing goals of the 1986 Superfund
Amendments and Reauthorization Act (SARA) by establishing a
site-specific decision process. Under this process, cleanup
options must satisfy the threshold criteria of protecting human
health and the environment and comply with the applicable or
relevant and appropriate requirements ("ARARs") of
other federal and more stringent state environmental laws.
Tradeoffs among options that meet the threshold criteria are then
balanced with respect to seven additional criteria that reflect
the SARA's mandates to "utilize permanent solutions . . .
and treatment technologies to the maximum extent
practicable" and to be cost-effective. Neither SARA nor the
NCP prescribes in detail how to ensure "protection" or
how to compare or match options for the protection of health and
the environment. Indeed, cleanup decisions often have to satisfy
competing criteria in the statute and the NCP, such as long-term
effectiveness and permanence of remedy; reduction of toxicity,
mobility, or volume; short-term risks (especially to workers);
and costs. Acceptability to states and communities is also a
relevant criterion.
In the years since promulgation of the NCP, EPA has put into
place several rounds of administrative reforms to achieve a
"faster, fairer, more efficient" program and address
"worst sites first" under the constraints of the
current law. In the last few years, EPA has emphasized the
importance of using reasonably anticipated future land use in
site-specific risk assessments and cleanup decisions; issued
several important groundwater guidance statements to implement
recommendations of the National Research Council; acted to
protect small parties, prospective purchasers, and innocent
landowners from liability; instituted a risk-based
priority-setting scheme for funding cleanup actions; and
accelerated cleanups through, for example, presumptive remedies
and the Superfund Accelerated Cleanup Model. It has also
initiated the Brownfields Action Agenda and its pilot program,
which seeks to empower states, communities, and other
stakeholders through economic redevelopment, safe cleanup, and
sustainable reuse of contaminated properties. EPA must face the
challenge of implementing these improvements and goals
consistently in its 10 regions and in states, territories, and
tribal jurisdictions and of meeting reasonable expectations for
cost effectiveness.
There is also a critical link between Superfund, the cleanup
program for hazardous waste sites no longer in use, and the
Resource Conservation and Recovery Act (RCRA) for management of
wastes currently being generated. Designing Superfund cleanups
and corrective actions under RCRA to comply with applicable
requirements for the treatment, storage, and disposal of RCRA
hazardous waste has been difficult. Guidance on using
treatability variances to comply with land-disposal restrictions
and more-recent regulations governing Corrective Action
Management Units (CAMUs) help, but compliance is still too
complex.
FINDING 6.1.2.1: Superfund can be said to
have caused more frustration than any other environmental,
health, or safety regulatory program, because of unexpectedly
large numbers of sites, high costs associated with clean up of
individual sites, high transaction costs caused by disputes about
responsibility and liability, excessive delays, and until
recently, a limited number of sites cleaned up. Some remedies
have been technically ineffective or so expensive as to be
financially punitive. Remedy selection has not consistently
considered future uses or realistic exposure scenarios. In
contrast, the highly successful emergency removal actions of
Superfund are not well appreciated, despite its timely and major
contribution to reduction of public-health and ecologic risks.
RECOMMENDATION: Risk assessments and remedy
selection should be based on reasonably anticipated current and
future uses of a site. As EPA's Land Use Directive of 1995
states, reasonable assumptions about future land uses should be
developed early in a process of seeking consensus with local
officials and community representatives, Congress should
encourage reuse of brownfields, those sites in urban areas where
economic use is avoided because of liability concerns. Also,
Congress should grant EPA broader authority to develop
enforceable institutional controls.
RATIONALE
Land-use and other resource-use assumptions play a critical
role in determining how clean a site must be for adequate
protection of health and the environment which is one primary
criterion under the Superfund NCP. A playground and an industrial
warehouse are associated with very different potential-exposure
scenarios and therefore need different remedial approaches with
potentially differing costs to achieve the same estimated level
of health protection. EPA's administrative actions and pilot
projects to promote the reuse of brownfields include guidance
documents about early consideration of future use, extensive
coordination with communities and other stakeholders, deferral of
NPL listing determinations while states oversee response actions,
voluntary cleanup programs, and model agreements for purchasers.
Inclusion of affected communities from the start as partners
in the investigation and remedy-selection processes, although it
might seem to impose an additional step and concomitant delay,
can improve the likelihood that the choice of remedy will reflect
reasonably anticipated uses of the site and wishes of the
community and reduce the dissonance and long delays often
observed if goals and costs are debated only after EPA has
proposed a remedy. Such a process is consistent with the
Commission's risk-management framework.
Use of enforceable institutional controls, such as
hazardous-substances easements, can make it feasible to
protect health and the environment reliably into the future at
cleanup levels that are less stringent than residential levels.
For example, thoroughly cleaning up of a former industrial site
in an urban area to a standard safe for young children would be
unnecessary and might be so expensive as to preclude
redevelopment. Such redeveloped sites might provide
economic-development opportunities in depressed areas and save
pristine areas elsewhere. Assurances for non-NPL sites that
brownfield development under qualified state programs will
protect cooperating prospective purchasers from Superfund
liability must be accompanied by a continuing monitoring program
so that potentially hazardous migration of contaminants from a
site can be predicted, detected, and remedied before substantial
risks to health or further environmental contamination can occur.
Hazardous on-site exposures due to changes in land use or failure
to control access must also be prevented.
FINDING 6.1.2.2: EPA needs additional
guidance about choosing risk-based cleanup standards. Remedy
selection and cleanup standards are complicated by innumerable
and sometimes conflicting ARARs (applicable or relevant and
appropriate state, or other federal requirements), including
state legal requirements to clean up to "background."
RECOMMENDATION: EPA should continue to use
its 10-6 > 10-4 risk range as a guide
for site-specific risk-based cleanup goals. Site-specific data
from the Remedial Investigation/Feasibility Study process should
be used to refine default assumptions when available. Because a
risk estimate is a result of many assumptions and judgments about
choice of data sets, it is wise for Congress to eschew setting
specific risk levels, leaving that decision to EPA and the
states. The Commission prefers qualitative language in
legislation, such as "reasonable certainty of no significant
harm." The ARAR provision of the Superfund law should be
amended to delete the "relevant and appropriate"
language because it is subject to wide differences in
interpretation, while retaining "applicable
requirements."
RATIONALE
The risk range is being used productively by EPA. We recommend
realistic high-end exposure scenarios for screening assessments
and descriptive or probabilistic distributions or ranges of
exposure for refined risk assessments (see section 3.2).
There has been too much confusion and conflict over the ARAR
provision and little use of the ARAR-waiver clause. The state and
federal regulations that can serve as ARARs were often not
written for conditions at Superfund sites, and they greatly
complicate remedy selection and implementation. We support
retaining applicable state and federal requirements as long as
they do not conflict with the risk-based goals tied to future
land use, as recommended in the preceding section.
FINDING 6.1.2.3: There are many difficulties
in the implementation of the balancing criteria of the National
Contingency Plan for Superfund. For example, the requirements
introduced in SARA in 1986 to "utilize permanent solutions
and . . . treatment technologies to the maximum extent
practicable" have been applied inflexibly at some sites.
Especially at nonresidential sites, interruption of exposure
pathways and other controls might be more appropriate than
treatment. Worker protection and cost containment require more
attention.
RECOMMENDATION: The mandate to use permanent
solutions "to the maximum extent practicable" should be
changed in the law to assurance of long-term reliability of
protection of health and the environment. The preference for
using treatment for the reduction of toxicity, mobility, or
volume as a principal element should be targeted at highly
hazardous material to ensure long-term reliability and should be
overridden when no effective treatment remedy is available. EPA
should continue to develop better mechanisms for proper
compliance with RCRA hazardous-waste standards at Superfund and
RCRA corrective-action sites, such as the Hazardous Waste
Identification Rule for contaminated media. A design-team
approach, including states and responsible parties, should be
encouraged to accelerate the remedial-design phase of the
cleanup. Remedies should be chosen to be most cost-effective in
meeting necessary protective cleanup levels.
RATIONALE
EPA, the states, potentially responsible parties, and citizens
often are timid about applying on-site remedies that reduce
toxicity, mobility, or volume of contaminants--incineration,
solidification, vapor extraction, and bioremediation--and about
restrictions on use. Remedies involving removal to
"elsewhere," usually landfills or off-site
incinerators, generally are high-cost remedies and often are
resisted by local communities anxious about numerous truck trips
to haul away contaminated material or fearful of incineration and
incineration malfunction. Parties must be encouraged to negotiate
phases of cleanup, especially when even expensive remedial
actions are inadequate for some aspects of the site, such as
30-50 years of pumping and treating groundwater contaminated by
dense nonaqueous-phase liquids or construction of major terrain
changes. On-site technologies that reduce toxicity, mobility, or
volume should be used when appropriate. They should not be
labeled as "innovative," which is a kiss of death for
decision-makers; instead, they should be identified as EPA has
begun to do, as "presumptive remedies" for appropriate
sites and cleanups. Responsible parties should be given
opportunities to propose and select alternative remedies if those
remedies can meet overall cleanup objectives--including
risk-based or residual contaminant or exposure levels-- agreed on
through a process open to public scrutiny. The least-expensive
remedy is not always the most cost-effective; multiple health and
ecologic effects might need to be balanced, as might community
cultural, social, and political factors.
One aspect of the law that makes implementation of Superfund
cleanups especially difficult is RCRA land-disposal restrictions,
which discourage intrasite movement of wastes for
less-intensive--yet efficient--treatment on-site. EPA has taken
steps to reduce the problem via its Corrective Action Management
Unit Rule and soon through its Hazardous Waste Identification
Rule for contaminated environmental media, but the 104th Congress
should remove the impediment to effective and efficient cleanup.
Enactment in April 1996 of H.R. 2036, the Land Disposal Program
Flexibility Act, provides a platform for complementing RCRA
remediation reforms.
FINDING 6.1.2.4: Superfund program costs have
exceeded billions of dollars over 15 years and will increase. A
budget process is needed to assure taxpayers and consumers that
costs are being controlled. In general, decisions seem to be made
without consideration of the aggregate effects, as though the
capacity of taxpayers and consumers to support the federal and
industry costs, as well as costs of responsible municipalities,
is unbounded.
RECOMMENDATION: The entire national Superfund
program--whether funded from the Superfund, private parties,
municipalities, or some combination of those sources--should have
an overall annual budget estimate so that Congressional
appropriation and taxation decisions and EPA program actions can
be better informed on a national scale. EPA's recently initiated
risk-based allocation of cleanup funds should be developed for
use in a budgeting and regulatory-impact analysis.
RATIONALE
The Commission believes that decentralized decision-making in
regional EPA offices and in various states under authorized
programs or Superfund cooperative agreements has led to many
impractical and unduly expensive remedies, inconsistency, and
limited learning from experience. Because potentially responsible
parties must cover the costs of many remedial actions, there is
little incentive for federal and state agencies to define a
maximal cost when the record of decision (ROD) is made.
In the Bush Administration, EPA Administrator William Reilly
proposed a "worst risks first" approach, but
implementation has been inconsistent. Current EPA Administrator
Carol Browner's policy and program initiatives have helped but
could be enhanced by an assessment of aggregate needs and
priorities. It will be difficult to propose and implement a
budget plan for Superfund. The DOE Environmental Management
Program constitutes an emerging example.
FINDING 6.1.2.5: Once a record of decision
(ROD) has been issued at a Superfund site, it has been difficult
to revise the remedy selection, even when better and cheaper
remedies have been identified later. In addition, changing
policies on consideration of future land use could make it
possible to alter the remedy in favor of a less expensive and
smaller risk reduction.
RECOMMENDATION: EPA should expand and
implement its new policy directive to address some general
problems in older RODs. The agency should initiate changes in
those RODs, or in response to petitions, and establish criteria
for selective revision of RODs for particularly inappropriate
remedies required in the past.
RATIONALE
EPA should establish procedures to provide appropriate and
efficient redress of remedial actions in existing RODs in certain
limited cases, such as land-use restrictions, development of
important new scientific information, or technologic advances.
Companies and communities that invested in cleanup of NPL sites
during the first 15 years of a steep learning curve for EPA and
the nation should receive the benefits new information and new
technology can bring. For example, reassessment of 30 - 50 years
of pumping and treating of groundwater after initial reduction in
contamination levels seems appropriate for reopening RODs.
Protections must be included to avoid an avalanche of petitions
to an agency without sufficient resources to respond and to avoid
triggering unintended litigation. The Commission is encouraged by
EPA's "remedy update" reform currently being
implemented administratively. This effort is targeted primarily
at bringing older groundwater RODs up to date with current
science and technology regarding appropriate cleanup objectives
for different types of contamination problems, such as
containment and removal of dense nonaqueous-phase liquids.
FINDING 6.1.2.6: There is a continuing need
for information and education on the toxicity of various
chemicals, physicochemical characteristics of contaminants,
sources of exposure, and effectiveness of remedies.
RECOMMENDATION: Congress should continue to
support essential support programs for Superfund--the Agency for
Toxic Substances and Disease Registry (ATSDR), the National
Institute of Environmental Health Sciences (NIEHS) Superfund
Basic Research Program at universities, NIEHS programs for
training for hazardous-waste workers training programs and
applicable EPA research and demonstration activities. The
Superfund program should make greater use of EPA's own Science
Advisory Board. If, as expected, more responsibility and funding
for site-specific decision-making are delegated to the states,
research and public-health assessment functions should continue
to have high federal priority.
RATIONALE
Despite extremely challenging deadlines and inadequate data at
many sites, ATSDR has made a valuable contribution to the
Superfund program through its toxicological profiles of various
common contaminants at Superfund sites, its public health
advisories (in collaboration with local and state health
departments), and its establishment of several exposure
registries. That work should continue. The Superfund
basic-research program administered by NIEHS under the Superfund
appropriation has mobilized highly relevant interdisciplinary
research at 17 universities. If Congress and the American people
want risk estimates and remedies that are based on sound science,
not default assumptions, support for research programs that
address them is critical and is a federal responsibility. Good
science does not of itself lead to application; Congress must
also support EPA's research activities. Similarly, worker
training and worker protection for the relatively high risks
involved in the clean up of sites are continuing
responsibilities.
EPA's Technology Innovation Office has a private-public
partnership program coordinated by Clean Sites involving major
companies with Superfund responsibilities, vendor companies with
new or not widely used technologies, DOE or Department of Defense
facilities, and state regulators. The program's demonstrations
provide objective comparative assessments in real-world
circumstances. They should be expanded, and their findings should
be widely disseminated.
The authority and mandates of the Office of Prevention,
Pesticides and Toxic Substances (OPPTS) are included in the
Pollution Prevention Act, the Federal Insecticide, Fungicide and
Rodenticide Act (FIFRA), the Federal Food, Drug and Cosmetic Act
(FFDCA), and the Toxic Substances Control Act (TSCA). The subject
of pollution prevention is discussed in section 5.4 of this
report. This section focuses on issues related to the toxicity
and registration of pesticides and on toxic substances.
FINDING 6.1.3.1: When EPA is precluded by the
"Delaney clause" from issuing a tolerance for a
pesticide, that pesticide cannot be used on a crop even if it
meets all the requirements for registration under FIFRA and for a
tolerance under section 408 of FFDCA. Thus, the Delaney clause
effectively pre-empts the risk-benefit framework for regulation
established in FIFRA and section 408 of FFDCA.
RECOMMENDATION: Pesticides should be exempted
from regulation under section 409 of FFDCA and be regulated
solely under FIFRA and section 408 of FFDCA. The standard of
protection specified in section 408 should be changed to
"reasonable certainty of no harm" in keeping with the
Food and Drug Administration's well-established statutory
language. At the same time, the safety standard should be
improved to allow for advances in scientific understanding and by
requiring the consideration of potential highly exposed
populations such as children.
RATIONALE
Together, FIFRA and section 408 of FFDCA establish
risk-benefit comparison as the basis for pesticide regulation.
Section 3 of FIFRA states that the administrator of EPA shall
register a pesticide, provided that, among other requirements,
"when used in accordance with widespread and commonly
recognized practice it will not generally cause unreasonable
adverse effects on the environment" [section 3(c)(5)(D)].
"Unreasonable adverse effects on the environment" is
defined in section 2 as "any unreasonable risk to man or the
environment, taking into account the economic, social and
environmental costs and benefits of the use of any
pesticide" [section 2(bb)].
Section 408 of FFDCA provides requirements for establishing
tolerances for pesticide residues in both raw agricultural
commodities and processed foods. When a pesticide residue
concentrates in processed food to greater than its section 408
tolerance concentration for the raw agricultural commodity,
however, the processed-food tolerance is established under
section 409 of FFDCA. Section 409 (and not section 408) contains
the Delaney clause, which is a proviso to the general safety
standard. The Delaney Clause provides that "no additive
shall be deemed to be safe if it is found to induce cancer when
ingested by man or animal." Interpreted literally, the
Delaney clause requires application of a zero risk standard,
which precludes consideration of risks and benefits. In practice,
a pesticide can meet the standard for a tolerance under section
408, but can't be granted one if it is banned completely from
processed foods under section 409 (the "Delaney
paradox").
The conflicting requirements for pesticide regulation under
FIFRA and FFDCA are not always in the interests of public and
environmental health. Pesticides should be uniformly regulated
according to risk-based standards and risk-benefit comparisons,
such as those already provided for under FIFRA and section 408 of
FFDCA. These issues are addressed more broadly in section 6.3 of
this report, which focuses on the FDA.
If pesticides are to be regulated solely under FIFRA and
section 408 of the FFDCA, Congress should also consider
improvements to the existing safety standard. The standard should
be flexible enough to account for changes in scientific
understanding and to address emerging risk issues. For example,
the National Research Council report Pesticides in the Diets
of Infants and Children (NRC 1993) concluded that current
tolerance-setting practices might not adequately protect
children. The safety standard in section 408 of the FFDCA should
be amended to require appropriate agency actions to ensure the
adoption of the key recommendations of the NRC study.
FINDING 6.1.3.2: Historically, EPA has made
its regulatory decisions chemical by chemical, including
pesticide-registration decisions. That approach does not
accommodate consideration of the potential effects of exposures
to several chemically different pesticides with similar effects
or of multiple exposures to chemically similar pesticides. EPA
considers multiple exposures and multiple risks when it evaluates
pesticides for the purpose of reregistering them, but it does not
yet do so during the evaluation of new pesticides.
RECOMMENDATION: EPA should establish an
integrated approach to the registration process to evaluate
multiple risks and exposures to multiple agents and to compare
the risks and benefits associated with alternatives, provide a
more complete evaluation of exposures and risks. Furthermore, to
encourage development of safer pesticides and reduction in the
use of more hazardous alternatives while avoiding market
disruption, EPA should expand its accelerated registration
program for the products that meet rigorous and well-defined
criteria for high human-health and environmental-safety
standards. Products that meet the high standards should be
permitted to carry EPA-approved labels to communicate to the user
that they meet high safety standards.
RATIONALE
EPA has avoided using an integrated approach to registration,
because of the potential for serious disruption of market forces,
such as shortages due to the loss of minor-use labels important
to fruit and vegetable growers and pesticide-resistance problems
as the number of pesticide products on the market is reduced.
Instead, the agency has encouraged the substitution of biologic
pesticides for more hazardous chemicals and the use of
formulation changes and equipment modifications to decrease
exposure. It has canceled some of the uses of pesticides that are
particularly hazardous, such as parathion. And it has established
a restricted-use category for needed but highly toxic pesticides
to ensure that they will be used only by pest-control operators
and agricultural workers qualified by training and experience to
use them properly. For the agency to improve the rational use of
pesticides and minimize their adverse effects by establishing an
integrated approach to evaluation of multiple risks and of
exposures to multiple agents, the agency should introduce the new
approach on a demonstration basis, to avoid disruption.
EPA has a long-standing commitment to developing safer
pesticides and alternatives to chemical pesticides. By creating a
safer pesticide-registration and pesticide-labeling program, EPA
can encourage development of safer alternatives and elimination
of highly hazardous materials. A pesticide registration and
labeling policy would give manufacturers an incentive to develop
safer alternatives and and give consumers information on which to
base informed choices. The marketplace can operate to reduce or
eliminate exposures without the disruption and spot shortages
that can be caused by an integrated approach.
FINDING 6.1.3.3: In recent years, review
requirements for new chemicals and advances in the understanding
of chemical toxicology have made important contributions to a
lower incidence of new findings of carcinogenicity and other
adverse effects among chemicals marketed. The Toxic Substances
Control Act (TSCA) has not been reauthorized since its enactment
in 1976, however, and EPA is mostly limited to review of data
submitted, without being able to specify what studies should be
conducted.
RECOMMENDATION: TSCA should be updated to
reflect advances in toxicology and regulation over the last 20
years. Congress and EPA should clarify what kinds of toxicity,
clinical, and exposure data should be generated as required under
section 4 and reported under section 8 of TSCA.
RATIONALE
To help EPA with the continuous review of chemicals,
manufactureres are responsible for reporting studies and other
information that indicates the likelihood of adverse effects
associated with their products. However, the extent of company
responsibilities for reporting information on chemicals proposed
to be marketed and chemicals not further developed is not always
clear. EPA/OPPTS is seeking to clarify both under TSCA 8(e) and
FIFRA 6(a)(2) what studies and human adverse-event reports must
be submitted to the agency.
OPPTS should devise means of analyzing technical information
submitted under section 8, to address generic scientific and
policy questions. For example, does use of a second species in
toxicology tests add sufficient information to influence
risk-management decisions? Are there biologically important
correlations between the occurrence of tumors and other end
points? TSCA potentially could provide a richer database than the
National Toxicology Program (NTP), although without the
systematic quality control of NTP bioassays. An analysis of new
and old data that are required to be submitted under section 8(e)
and 8(d) should be a joint effort of OPPTS and the Office of
Research and Development/NCEA. Requirements to test chemicals
have seldom been imposed; the threshold for issuing such a test
rule is considered to require more extensive data than are
available to justify it. Together, EPA and Congress should
clarify section 4. Companies are required under TSCA 8(c) to
retain files with reports of health effects in people exposed,
but are not required to submit such files. EPA, industry,
academics, and worker and consumer representatives could be
brought together to propose criteria for making use of such
information, relating it to use and exposure data to generate
estimates of incidence rates, and developing practical analogies
to the FDA adverse drug reaction reporting and analysis scheme.
The OECD recommends a basic set of testing requirements for
new chemicals that are to be introduced to the market in member
countries. Testing requirements are tiered and increase as the
market for a product develops. Given the limitations of EPA's
ability to require testing under TSCA and the absence of data
accompanying new submissions, Congress should consider providing
EPA with similar authority to specify what studies should be
conducted by the manufacturer.
EPA is expected to propose testing protocols and testing
requirements for effects of chemicals on endocrine functions,
especially estrogenic, anti-estrogenic, and androgenic effects.
At the first meeting of the Commission in May 1994, we invited
Theo Colburn to discuss observations in wildlife, fish, and
humans of changes in reproduction, gender-specific behaviors,
sperm count, and incidence of anomalies of the genitalia. The
terms "endocrine disrupters" and "endocrine
modulators" have emerged as descriptive of a wide range of
such effects (Davis and Bradlow 1995, McLachlan and Korach 1995,
Colburn et al. 1996). Some, but not all, are mediated by or
attributed to compounds that bind to estrogen receptors. Some are
chlorinated compounds, but many others are not (alkylethoxylate
plasticizers, for example).
Many scientific issues related to endocrine
"disruptors" are just being framed. This topic stands
at the hazard-identification stage of the risk-assessment
framework (section 1) and the problem/context stage of the
Commission's risk-management framework (section 2): How do
agonists and antagonists interact (estrogens and antiestrogens)?
How predictive are the complex endocrine assays? How do we
estimate risks associated with exposure to very low doses of
environmental estrogenic chemicals when dietary doses of
naturally occurring estrogenic compounds (phytoestrogens, such as
flavonoids) are so much higher? Even higher than dietary doses of
estrogenic chemicals are ingested in the form of oral
contraceptives and post-menopausal hormone replacement therapy.
The National Research Council has established the Committee on
Hormone-Related Toxicants in the Environment to assess their
known and suspected modes of action and potential toxicity and
impacts on wildlife and humans. EPA's Health Effects Research
Laboratory has been working to identify those modes of action for
some years. And the Chemical Industry Institute of Toxicology has
announced that a portion of their budget has been reallocated to
initiate a program of research on endocrine effects.
The Commission supports giving priority to the scientific
assessment of the potential toxicity of this class of chemicals.
The EPA Office of Water has responsibility for protecting the
nation's surface water and groundwater and ensuring the supply of
safe drinking water for the public. The Clean Water Act was
enacted in 1972, soon after the dramatic incident in which the
Cuyahoga River in Ohio caught fire because it was so polluted.
Water quality has improved substantially since then.
Nevertheless, about 35% of America's surveyed rivers, lakes, and
streams still do not meet standards for their designated uses
(OECD 1993). Point sources of pollution have been controlled to a
great extent; now state water-quality managers have identified
nonpoint sources, such as urban and agricultural runoff, as the
largest contributors to water-quality problems.
The Clean Water Act regulates point-source and nonpoint-source
discharges of pollutants to the waters of the United States.
States establish water-quality standards based on the designated
use of a water body--such as providing fish for consumption,
agriculture, or drinking water--and on the quantitative or
narrative water-quality criteria that are required to support a
particular use. Point sources obtain permits for discharges based
on available treatment technologies and on the quality of the
water receiving the discharge and its designated use. Effluent
guidelines for a particular point source are based on either
available technology or water quality. Technology-based effluent
guidelines set a consistent, industrywide level of control and
are imposed at the point of discharge; if they prove to be
inadequate to meet the water-quality standards for a particular
body of water, additional controls are implemented to meet
effluent limits based on water quality. Effluent limits have been
established for over 100 pollutants discharged by 51 categories
of industry and are based on the best available technology that
is economically achievable. For nonpoint sources of water
pollution, states use grants from EPA to develop control
programs, usually providing for implementation of best management
practices.
The Safe Drinking Water Act of 1974 as amended requires EPA to
set drinking-water standards to protect human health from both
naturally occurring and anthropogenic contaminants, and it
specifies requirements for water treatment. Standards have been
formulated for more than 80 contaminants. For each regulated
pollutant, EPA publishes an unenforced maximum-contaminant-level
goal based solely on health considerations and promulgates a
standard that includes both health and feasibility
considerations. Feasibility is determined by considering
available technology and cost. The importance of safe drinking
water was driven home in April 1993, when Cryptosporidia
in the Milwaukee water supply caused an epidemic resulting in
death and severe intestinal disorders.
The following recommendations are intended to build on the
important improvements of the last 25 years in surface water,
groundwater, and drinking water.
FINDING 6.1.4.1: The Clean Water Act
regulates sources of pollution in a manner that has resulted in
fragmented programs that do not adequately address the health of
the watershed ecosystem or sufficiently involve communities,
states, and others in multijurisdictional management and
protection of water quality.
RECOMMENDATION: The Clean Water Act should be
amended to establish a comprehensive, integrated
watershed-management approach that uses ecological risk
assessment and biotic-integrity measurements and to provide for
the development of state watershed programs. The state programs
should be subject to EPA approval and oversight and have
substantial involvement by stakeholders and other appropriate
federal, state, and local agencies.
RATIONALE
Over the last 25 years, pollutant discharges into the nation's
rivers, lakes, estuaries, coastal waters, and wetlands have been
greatly reduced. Much of the success has been achieved through
the control of municipal and industrial point-source discharges
into water bodies under programs established by the Clean Water
Act. However, the health of an aquatic ecosystem can be affected
not only by point sources of pollution but also by nonpoint
sources such as urban and agricultural runoff. And it can also be
affected by activities that disturb the land, including logging
and grazing, construction (especially of dams and reservoirs),
diversion of surface-water and groundwater flows for domestic and
agricultural uses, overfishing, introduction of exotic species
into water bodies, and deposition of air pollutants. Russell Jim
of the Yakama Indian Nation spoke to the Commission about the
contribution of several of such phenomena to the decline of
salmon populations in the Pacific Northwest. The clean-water
programs take a fragmented approach to those problems and do not
provide for integrated environmental management of the watershed
ecosystem. With a watershed-management approach, ecosystems and
human health could be better protected from the cumulative
effects of a multitude of natural and human activities.
The watershed-management approach is a comprehensive,
geographically based approach that recognizes all resources
within a hydrologically defined watershed as parts of an
interconnected system that depends on the health of the parts to
sustain the healthy functioning of the ecosystem. Ecological risk
assessment and the index of biotic integrity (see section 3.4)
can be important tools in identifying stressors of the watershed
and characterizing their impact on various plant and animal
species. For example, ecological risk-assessment case studies
being examined by the Office of Water include a wide array of
ecological organization, including individuals, communities,
habitats, landscapes, ecosystems, and combinations of these. The
watersheds examined include the Snake River, the Middle Platte
River, Waquoit Bay, and Big Darby Creek.
Watershed management should focus on identifying priorities
and tailoring solutions to the specific set of problems found in
a watershed. The estuary programs in Tampa Bay and Galveston Bay
are good examples of state- and local-governments and citizen
participation in a process that identifies high-priority
environmental problems for the estuaries and institutes action to
ameliorate the problems. Those two programs are also good
examples of a multimedia approach to environmental problems, in
that atmospheric deposition was found to be an important source
of potential water pollution in both locations.
Achieving greater efficiency and effectiveness through
watershed management will depend on building partnerships and
integrating federal, regional, state, tribal, territorial, local,
and private programs within the watershed.
FINDING 6.1.4.2: Regulation of water
pollution under the Clean Water Act is implemented generally
through effluent limits based on technology and water quality.
Ecologic and human-health risk assessments provide information
that is used to help set effluent limits based on water quality
and criteria for receiving-water quality. Risk assessments are
also used to set regulatory priorities.
RECOMMENDATION: EPA and the states should
continue to use receiving-water quality and risk-assessment
results (and other considerations) to set priorities for the
development of various water-pollution control programs. Risk
assessment should also be used, where appropriate, to establish
water-quality criteria and effluent limits based on water
quality. However, risk-based effluent limits should not yet
supplant technology-based and quality-based techniques for
reducing water-pollutant discharges and protecting water quality.
RATIONALE
Risk assessment provides useful information for making
decisions about the best ways to control water pollution. EPA
uses human-health risk assessment to derive water-quality
criteria intended to protect human health. In contrast, ecologic
risk assessment is not yet likely to afford adequate descriptions
of risks to complex aquatic systems (see section 3.4). For
example, the impacts of endocrine "disruptors" on fish
and on the offspring of fish-eating animals have not been fully
assessed. As an emerging tool, ecological risk assessment has not
yet reached the level of sophistication and reliability necessary
to support its use as the primary determinant of effluent limits
based on water quality.
FINDING 6.1.4.3: Methods to assess microbial
risks associated with drinking water are too limited for general
use, and data on risks associated with microorganisms,
disinfectants, and disinfection byproducts are sparse.
RECOMMENDATION: EPA should give a higher
priority to the improvement and application of methods for
assessing waterborne microbial risks and to the development of
data for assessing relationships among the occurrence of
microbial contamination, the use of disinfectants, and the
formation of potentially hazardous disinfection byproducts.
RATIONALE
Evaluating drinking-water quality includes assessing both
microbiologic risks and risks associated with disinfectants and
disinfection byproducts. Microbiologic contamination of
drinking-water supplies poses a clear threat to public health
when treatment is inadequate. In response to the threat, EPA is
developing a risk-assessment paradigm for evaluating human risks
associated with waterborne pathogens. Efforts to reduce potential
health risks associated with disinfection byproducts must not
compromise the microbiologic quality of drinking water.
A 1992 regulatory negotiation effort has recently produced the
Information Collection Rule, which establishes monitoring and
data-reporting requirements for large public water systems for
EPA to use in setting various drinking-water standards.
Implementation of the rule is hoped to lead to greater
understanding and better characterization of the risks associated
with microorganisms, disinfectants, and disinfection byproducts.
Additional data and analysis of those risks are needed before new
drinking-water standards are promulgated. Because implementing
new standards is expensive and because a large proportion of the
United States population is exposed, research should be focused
on characterizing risks related to different disinfectants and
disinfection byproducts and comparing them with microbial risks
so that the agency can target its activities toward the greatest
potential risk reduction.