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OCR for page 150
IV
Recommendations
The Committee has reviewed federal ri sk assessment for
hazards to public health, particularly for chemically
induced cancer, and has presented its findings concerning
the nature of r isk assessment ~ the nature and utility of
risk inference guidelines, and the effects of alternative
organizational arrangements on risk assessment. The Come
mittee's review leads to the general observation that the
process of risk assessment, as performed by and for fed-
eral regulatory agencies, has been developing rapidly in
recent years, both with respect to its scientific basis
and with respect to the agencies' organizational arrange-
ments. Change this rapid is bound to lead to m~sunder-
standing about the use of risk assessment in regulatory
policy-making, particularly if some misconstrue risk
assessment to be a strictly scientific undertaking. Much
of the criticism of risk assessment stems from dissatis-
faction with regulatory outcomes, and many proposals for
change are based largely on the unwarranted assumption
that altering the administrative arrangements for risk
assessment would lead to regulatory outcomes that critics
will find less disagreeable. Because risk assessment is
only one aspect of risk management decision-making, how-
ever, even greatly improved assessments will not
eliminate dissatisfaction with risk management decisions
The Committee believes that the basic problem with
risk assessment is not its administrative setting, but
rather the sparseness and uncertainty of the scientific
knowledge of the health hazards addressed. Reorganiza-
tion of the risk assessment function will not create the
data and underlying knowledge that assessors need to make
risk assessments more precise. We hold that the most
productive path to a solution has three parts:
150
OCR for page 151
151
· Implementation of procedural changes that ensure
that risk assessments take full advantage of the ava~l-
able scientific knowledge while maintaining the diverse
organizational approaches to administration of risk
assessment needed to accommodate the varied requirements
of federal regulatory programs.
· Standardization of analytic procedures among fed-
eral programs through the development and use of uniform
inference guidelines.
· Creation of a mechanism that will ensure orderly,
continuing review and modification of risk assessment
procedures as scientific understanding of hazards
improves.
The Committee offers in the following pages 10 recomb
mendations whose implementation it believes will meet
these general objectives.
IMPROVING RISK ASSESSMENT THROUGH PROCEDURAL CHANGES
BECOMME:NDATION 1
Regulatory agencies should take steps to establish and
maintain a clear conceptual distinction between assess-
ment of risks and the consideration of risk management
alternatives; that is' the scientific findings and policy
judgments embodied in risk assessments should be
explicitly distinguished from the political, economic,
and technical considerations that influence the design
and choice of regulatory strategies.
Although the Committee concludes that risk assessment
cannot be made completely free of policy considerations,
it also believes that policy associated with specific risk
management decisions should not influence risk assessment
unduly. }risk assessment and risk management involve dif-
ferent goals, kinds of expertness, and operating prin-
ciples. The goal of risk assessment is to describe, as
accurately as possible, the possible health consequences
of changes in human exposure to a hazardous substance;
the need for accuracy implies that the best available
scientific knowledge, supplemented as necessary by ass~mp-
tions that are consistent with science, will be applied.
The ultimate aim of risk management is to evaluate trader
offs between health consequences and other effects of
specif ic regulatory actions; this evaluation includes the
application of value judgments to reach a policy decision.
OCR for page 152
152
Experience shows the difficulties that can arise from
a blurring of the distinction between the two elements.
If risk management considerations (for example, the eco-
nomic or political effects of a particular control action
for a particular chemical) are seen to affect either the
scientific interpretations or the choice of inference
options in a risk assessment, the credibility of the
assessment inside and outside the agency can be co~pro~
mised, and the risk management decision itself may lose
legitimacy. Indeed, such consequences can flow from Me
mere perception, as well as the fact, of such influences.
Each regulatory agency should commit itself to safeguard-
ing the distinction between the processes of risk assess-
ment and risk management. One among several suggestions
f or accomplishing this safeguarding is to restructure the
formal organization, separating an agency's or program's
risk assessment staff from its policy-making staff, pos-
sibly by establishing a separate risk assessment unit
outside the agency. The Committee does not, however,
recommend that agencies use any particular organizational
arrangement for risk assessment. One might surmise that
separating the staffs would help to reduce the likelihood
that risk management considerations will influence risk
assessment, but our survey of agency structures provided
no clear evidence that such an influence was related to
the degree of administrative separation.
Formal separation has disadvantages that must be b=1-
anced against its value in maintaining a distinction
between risk assessment and risk management. Risk assess-
ment and risk management functions are analytically dis-
tinct, but in practice they do--and must interact.
Organizational arrangements that completely isolate risk
assessors from regulatory policy-makers may inhibit impor-
tant communication in both directions. For example, to
complete risk characterization, risk assessors must know
what policy options are to be used to calculate alterna-
tive projected exposures, and new opt ions may develop as
the risk management process proceeds. Moreover, direct
communication with the risk assessors is desirable to
ensure that the regulatory decision-maker understands the
relative quality of the available scientific evidence,
the degree of uncertainty implicit in the final risk
assessment, and the sensitivity of the results to the
assumptions that have been necessary to produce the
assessment. Such separation could also impair the risk
manager's ability to obtain assessments that are tamely
and in a useful form. The advisability of organizational
OCR for page 153
153
separation hinges on comparison of its benefits and costs
in particular agencies and programs.
Because drawbacks are likely to be most pronounced in
the case of extra-agency separation, the Committee does
not believe that it is appropriate to remove the risk
assessment function and place it in an organization com-
pletely separated from the regulatory agencies, as is
contemplated in the ALEC propose, and H.~. 638. This
judgment is supported by the conclusion that the benef its
of increased separation are uncertain and that the disrupt
tion and confusion caused by reorganization could be
considerable.
Measures other than organizational separation can
ensure the distinction between the assessment of risk and
the consideration of risk management alternatives. These
measures include the practice of preparing written risk
assessments (Recc~endation 2), arranging for independent
peer review (Recommendation 3), and adhering to uniform
guidelines for risk assessment (Recommendations ~ through
9) .
REC~DATION 2
Before an agency decides whether a substance should or
should not be regulated as a health hazard, a detailed
,
and comprehensive written risk assessment should be
,,
prepared and made ~
sh between the
,
scientific basis and the policy basis for the agenav's
conclusions.
. .
Although agencies commonly perform risk assessments
before they take regulatory actions, the written assess-
ments that are prepared vary in coverage, amount of
explanatory detail, format, and completeness to an extent
that limits their use as instruments of communication.
The Committee believes that the matters addressed are so
important and the consequences so far-reaching that a
written risk assessment should be prepared for every
significant regulatory decision and that each should be
clear, detailed, and comprehensive account of the analysis
performed. A written assessment should describe the vol-
u~e and weight of scientific evidence to help to clarify
the scientific and policy bases for regulatory decisions.
The written assessment should be made accessible to the
public at a time and in a form that facilitates public
participation in any attendant risk management decision.
OCR for page 154
154
The Committee believes that the requirement to prepare
a written assessment imposes a salutary discipline that,
for several reasons, will improve the performance of risk
assessment. First, the requirement to prepare a compre-
hensive written assessment will encourage the agency to
explain how each component of the assessment was treated;
that should minimize the likelihood that risk management
considerations will, unnoticed, affect the outcome of the
assessment. Second, a written assessment can help to
distinguish the factual basis of a risk assessment from
inferences drawn where there is a lack of scientific
consensus; this distinction will facilitate scientific
review of the risk assessment, document the scientific
basis of the assessment for outside observers, and
acquaint the regulatory decisions maker with the relative
completeness of the scientific evidence. Third, it will
aid communication among specialists working on different
parts of the assessment. Fourth, Me existence of an
explicit description should simplify the conduct of later
assessments of the same chemical, if additional scat es'
tific evidence comes to light or other regulatory
programs review the same substance. Finally, written
risk assessments will be useful to institutions that
oversee regulatory agencies, notably Congress and those
responsible for judicial review. It is important,
however, that the format and scope of written assessments
not become an independent basis for legal attack.
Content and Form
An agency s written risk assessment should set forth in
detail the nature and quality of the relevant scientific
evidence concerning the substance in question and should
cover a,1 relevant components of risk assessment. It
should reflect attention to any applicable guidelines
relied on in interpreting the evidence, so that a reader
can ascertain what inference options were used, and should
describe the scienti fic rationale for any departures from
methods prescribed in such guidelines. If the choice of
inference options is not governed by guidelines, the
written assessment itself should make e~licit the assume
tions used to interpret data or support conclusions
reached In the absence of data. The document should
acknowledge gaps and uncertainties in available
information.
OCR for page 155
An agency's written assessments are likely to prove
most useful if they follow a consistent format, so that
readers, once familiar with the format, can use them
efficiently. We believe that each program or agency can
establish a uniform structure for its written assess-
ments, and we hope that similarity, if not uniformity,
will be possible in written assessments prepared
throughout the government.
Actions Covered
This recommendation is not intended to apply to the risk
posed by every substance, use, or exposure that engages
an agency' s attention. It is intended to apply to agency
decisions concerning important human exposure to a hazard.
Such decisions would include (but not be limited to)
establishment of an occupational safety and health stan-
dard by OSLO, cancellation },y EPA of the federal regis-
tration of a pesticide to which there is widespread human
exposure, and EPA promulgation of limits for an air or
water pollutant. The categor ies of actions covered by
this recommendation could be defined precisely only after
detailed statutory analysis. EPA appears to have had
satisfactory experience with the practice of classifying
its regulations as ~major" (those with very large economic
and other effects that require an extensive regulatory
analysis and formal review by the Office of Management
and Budget), ~significant" (a larger category defined by
internal EPA criteria), and "minor" (a similarly large
group of routine and technical actions). We suggest that
EPA prepare a written assessment for every major and
significant action, and we encourage other agencies to
devise similar methods of identifying which regulatory
actions require written assessments.
An agency's decision to refrain from regulation can
often have important consequences, both for health and
for the economy, and such decisions should rest on
accurate, objective assessments of risk. The denial of a
petition to act on a chemical to which exposure is
extensive is an example. When an agency is confronted
with choosing between limiting exposures to a substance
and taking some lesser action and there is serious dispute
over the character or extent of the risk posed, a written
assessment is advisable.
OCR for page 156
156
RECOMMENDATION 3
An agency's risk assessment should be reviewed by an
independent science advisory panel before and major
regulatory action or decision not to regulate. Peer
review may be performed by science panels already
established or authorized under current law or, in their
absence, by Panels created for this Purpose.
.
of an agencies workload is substantial, a
standing advisory Panel (or Panels) should be established
to review its risk assessments otherwise, ad hoc panels
should be established on a case-by-case basis.
· Panel m-miners should be selected for their
l
scientific or technical competence.
· The appointment of members should be the
responsibility of each agency director, but nominations
,
from the public and scientific organizations should be
,
;n~it=A unlay current law nreseribeS another Procedure.
Panels should Provide to the referring agencies
written evaluations
evaluations should be available for Public inspection.
.
This recommendation endorses outside peer review of
agency risk assessments.. Such review should contribute
to the important distinction between risk assessment and
risk management, because risk management information
would be excluded from the review; should improve the
scientific quality of the assessments through the process
of criticism and response; and should increase the credi-
bility of agency assessments. The practice of preparing
written risk assessments will facilitate the review
process.
The peer review function that we visualize is already
evident in some agencies. We believe that a single
approach would not fit all contexts, but that any mech-
anism for scientific peer review should meet the general
criteria described below.
Panel Form
The review function we recommend could be performed
effectively by an appropriately qualified standing panel
of independent scientists that is responsible For reviews
ing agency assessments of a particular class of hazards.
Any agency program responsible for a large number of
OCR for page 157
157
compounds to which humans are exposed in large amounts
seems to be an appropriate candidate for a standing
scientific review panel, but some programs may deal with
so few chronic health hazards that a standing panel is
not warranted. The Committee specifically contemplates
that the review function recommended here can be per-
formed by panels already available to several agency
programs.
Panel Composition and Selection
.
Members of a scientific review panel should be selected
for their competence in fields relevant to the assessment
of risks of the kind being evaluated. In our judgment,
employees of private business organizations, members of
environmental groups, and government research or regula-
tory agency employees should not necessarily be disqua}i-
fied; but no panel members should be employees of the
acenav whose rose assessments are ~~ vet ~ rev `~-c" ~ rev ~
_ 7 _ _ ~
should any members participate in the review of sup
stances in which they or their employers have substantial
economic or other interests or on whose resect my ~~
their employers have publicly taken a position. It is
important to safeguard both the reality and the appea~-
ance of complete objectivity for each review.
We contemplate that, as is common for existing panels,
the appointing official would be the head of the agency
whose r isk assessments are to be reviewed. Such an
arrangement could be thought to jeopardize a panel's
independence from the agency, particularly in cases in
which it is known which chemicals the panel will review.
Accordingly, each agency should establish procedures for
obtaining nominees for panel membership whose objectivity
is ensured. For example, some current procedures call
for agency selection of members from lists of nominees
provided by the President of the National Academy of
Sciences and by the Directors of the National Institutes
of }realm and the National Science Foundation. We see no
magic in any particular nomination process. The impor-
tant objective is a process that, first, ensures that
panel members are selected for their training and experi-
ence in relevant fields; second, prevents the appointing
official from forming a panel that will produce (or appear
to produce) a predetermined result; and, third, operates
expeditiously. We recommend that this process include an
opportunity for members of the public to nominate persons
for panel membership.
OCR for page 158
158
Panel Functions
our recommendation contemplates that, in a typical case,
the responsible agency Will have prepared a written
assessment of the risk posed by a substance. The index
pendent scientific panel would be asked to review that
assessment for comprehensiveness, scientific accuracy,
and consistency with any applicable risk assessment
guidelines. If such guidelines are flexible, an impor-
tant panel function will be to ensure that departures
From the inference options favored by the guidelines are
justified on scientific grounds. In performing this role,
the panel should, if it desires, have access to all the
data available to the agency, including those on which
the agency's analysts relied, as well as the agency's
written assessment. The pane' should subject the agency'
risk assessment to such scrutiny as the members find
necessary to satisfy themselves that it is, with or with-
out revisions, as complete and objective as available
data permit. The panel should provide a written evalua-
tion of the agency risk assessments including recommend
cations for revision, if appropriate. This evaluation
should be available for public examination by the time
the agency initiates public proceedings to alter hen
exposure to the substance in question for example, when
the agency issues a notice of proposed rule-mak~ng.
Panel Agenda
Independent review of agency risk assessments is c~eslgnea
to ensure the integrity and quality of the scientific
bases for regulatory decisions affecting }groan health.
Therefore, the Committee recommends that every action,
including a decision not to regulate, that requires a
written risk assessment be available for independent
scientific review. A scientific review pane1's agenda
may also include risk assessments for other decisions of
interest to panel members, or its review could be
initiated after a request by a third party. In the
latter case, panels should have the authority to decide
whether or not to respond to such requests for review.
In general, the Committee expects that the panels would
exercise discretion in invoking their authority to review
assessments for routine, minor actions.
OCR for page 159
159
Timing of Review
Independent scientific review of agency risk assessments
should occur before an agency commences the public process
leading to regulatory action. The purpose is to expose
the agency's initial assessment of the risk posed by a
substance to expert scrutiny at a tome when review can
influence the agency' s course of action. Experience
suggests that agencies are less receptive to criticism of
the basis of their actions af ter they have announced a
proposed course of action. Furthermore, although index
pendent review can some times forestall misguided regula-
tory actions even after they are initiated, prior review
of such actions may help to avoid serious damage to agency
credibility and unnecessary costs to private interests
that would be adversely affected by public proposals for
regulatory action. We recognize an important exception
to our general recommendation of preaction peer review.
Several statutes expressly empower agencies to act in an
emergency to curtail human exposure to a substance that
poses a serious health risk. Agencies have also devised
informal procedures to effect Immediate protection of
humans exposed to dangerous substances in other contexts.
Our recommendation is not intended to cast doubt on the
legitimacy of such authority or to impede its appropriate
exercise. When an agency concludes that a hazard warrants
immediate regulatory action to limit human exposure, it
should be able to take action consistent with existing
law without first going through the review process that
we recommend. Promptly thereafter, however , the agency
should submit its written risk assessment for independent
review in accordance with the procedures outlined here.
Weight of Pane} Evaluation
A scientific review panel's critique of an agency's risk
assessment should not be binding; that is, the agency
should not be obliged to revise ~ ts risk assessment if
the panel regards it as deficient. Agencies have a
responsibility to state the basis of their actions, and
the authority for their actions must remain their own.
Serious panel criticism, however, would in practice cause
any agency at least to reconsider, and ordinarily to
r evise , its ~ isk assessment. The agency should discuss
any Important criticisms of its assessment in its proposed
regulatory action, and its response to a panel's criti-
OCR for page 160
160
clams would be an appropriate subject for public comment,
as well as a possible basis for judicial challenge to any
final action.
We believe that an important benefit of peer review
occurs before the review begins: risk assessors who
expect an assessment to be subjected to serious scrutiny
by eminent qualified reviewers are likely to be more
careful and clear about the use and limits of scientif Sac
evidence.
Federal Advisory Committee Act
The Federal Advisory Committee Act imposes many salutary
requirements on panels established to advise federal
agencies, including notably the requirement that panel
meetings be held in public. But the Act's requirement
that new advisory committees be chartered by the General
Services Administration imposes substantial delays and
its requirement that panel meetings be announced in the
Federal Register at least 15 days in advance can markedly
slow a panel's work. Consideration should be given to
modifying both requirements or exempting such panels from
the Act, as Congress did for CPSC's Chronic Hazard
Advisory Panels.
RECOMMENDATION 4
When two or more agencies share interest in and iurisdic-
-
tion over a health hazard epae i~ ~ c~nd~e tor cegula-
tion by them in the near term, a joint risk assessment
should be Prepared under the auspices of Me National
Toxicology Program or another aPuropr~ate organization.
Joint risk assessments should be prepared Primarily bY
scientific Personnel Provided by the agencies and
assisted as necessary bv other Government scientists.
1
This recommendation endorses coordination in assessing
the risks of chemicals that are likely candidates for
regulation by two or more agencies. Although all the end
uses of a substance may fall within the jurisdiction of
one agency (such as FDA for a food additive), exposures
occurring during production, transportation, and distri-
bution usually are within other agencies' jurisdictions.
Thus, chemicals that pose a hazard to human health are at
least theoretically subject to regulation by two or more
OCR for page 166
166
RECOMMENDATION 7
The process for developing, adopting, applying, and
revising the recommended inference guidelines for risk
assessment should reflect their dual scientific and
. . .
policy nature:
· An expert board should be established
develop
recommended guidelines for consideration and adoption by
regulatory agencies. The board's recommended guidelines
should define the scientific capabilities and limitations
in assessing health risks, delineate subjects of uncer-
taintv, and define the consequences of alternative
policies for addressing the uncertainties.
· The expert board1s report and recommendations
should be submitted to the agencies responsible for
regulating the hazards addressed by the guidelines for
their evaluation and adoption. The agencies, perhaps
with central coordination, should, when possible, choose
a preferred option from among the options that are
consistent winch
~ = ~ ]~ =~
members of the public to comment.
The process followed by the qoverrment for
adoption of inference Guidelines should ensure that the
resulting Guidelines are uniform among all responsible
agencies and are consistently adhered to In assessing the
risks of individual hazards.
.
.
The resulting uniform guise
nes should govern
the performance of risk assessments by all the agencies
that adopt them until they are re-examined and revised:
they should not prevent members of the public from
disputing their soundness or applicability in Particular
cases. In short the guidelines should have the status
.
of established agency procedures, rather than binding
regulations.
The guidelines should be reviewed periodically
with the advice and recommendations of the expert board.
The ^~ - cat Fox r - =is:ina ~h`? guidelines. like the process
for adoption, should afford an opportunity for comment by
all interested individuals and organizations.
Inference guidelines for risk assessment are based
largely on science, but other considerations are involved
in components with substantial scientific uncertainty.
For these, the choice among inference options can have
substantial policy ramifications. Thus, we recommend a
OCR for page 167
167
two-step process in which a board of experts recommends
guidelines and provides scientific commentary on avail-
able inference options and then the government adopts
final guidelines based in part on the board's
recommendations.
The Board and Its Role
The recommended guidelines should be developed by a
congressionally chartered board of experts who are
independent of regulatory policy-making. We describe
this board, its placement, and other functions that ~t
can serve in Recommendation 10.
In genera, terms, the
board should be permanent, should represent professional
excellence on a national scale, and should have facil ity
with issues that have policy ramifications. We see
advantages in locating the board outside the government.
The board's Cope is mainly scientific. It should
define the components of risk assessment and describe the
scientific basis for each. When it finds general scien-
tific agreement on the proper inference option for a
component, it should designate that option in a recomb
mended guideline. When the board finds no general
scientific agreement on the available inference options,
~ t should recommend against the use of options that are
scientifically unsupportable and comment on the relative
strength of the scientific support For the options that
remain.*
Agency Adootion
The Committee envisions that the second step in the
establishment of guidelines w'11 be in the hands of the
*Some members of the Committee believe that the board
should also be encouraged in such cases to recommend th e
option that it judges to have the most scient~f ~ c support,
as long as the board clearly indicates that such choice s
are based on m~ers' informed scientific judgment, not
on general agreement in the scientific community. Other
Committee members believe that such recommendations would
imply scientific certainty where none exists and thus
would result in scientists' improperly recommending
policy on the basis of their subjective judgments.
OCR for page 168
168
government. The choice of guidelines is, ultimately, the
responsibility of duly elected or appointed public
officials, and public review and comment on the proposed
guidelines should be completed before they are adopted.
The Committee emphasizes that, to be most useful, the
final guidelines should prescribe default options for all
components of r isk assessment. Thus, the second step
should f urther limit the inference options available to
the agencies, even for components In which the }board
found that no single option could be chosen on scientific
grounds. In that case, full consideration should be
given to the board's comments on the merit of the science
tragic support that is available for each option.
It is important that the process result in ~ timely,
uniform set of inference guidelines to be used by all
agencies. We thus see advantage in coordination of the
agencies' adoption of guidelines by a single, central
authority such as the Office of Science and Technology
Policy, or by a mechanism designated by Congress.
The Committee believes that adopting the guidelines as
established procedures, rather than as formal regu~a-
tions, would have several important advantages: it would
allow guidelines to be adopted and amended more easily;
it would bind the agencies to adhere to the guidelines
until they were reviewed and revised (thus fostering
predictability and consistency--any agency's failure to
comply with its own guidelines could be noted by index
pendent scientific review panels and could be cited as
grounds for interested parties' legal appeal of an
associated regulatory decision); and it would permit
members of the public to advocate new or alternative
approaches to risk assessment.
Joint risk assessments performed by interagency task
forces should be governed by the guidelines that emerge
f ram this process .
Uniformitv
The Committee has presented its case for uniformity in
guidelines: consistency in the conduct of risk assessment
reduces the appearance of unfair and inconsistent regular
tory policies, improves przority-setting among regulators'
programs, increases public understanding, and provides
coherence for those subject to various regulatory author-
ities. A frequent argument against government-wide gu~de-
lines is that different agencies have statutory respond
OCR for page 169
169
sibilities that reflect different social policies and
therefore require different approaches to risk assess-
ment. This argument reflects a misunderstanding of the
purpose of guidelines. An agency would remain free to
incorporate whatever social judgments are embodied in its
mandate when deciding whether and how to regulate. Such
risk management choices can be made independently of and
after the completion of a risk assessment. Thus, two
agencies could use the same risk assessment of a sub-
stance, but regulate it differently on the basis of
statutory or policy criteria applied after risk
assessment.
Periodic Review
The scientific basis of risk assessment is evolving
rapidly. Guidelines must continue to evolve to accom-
modate scientific innovations and theories. By their
very nature, guidelines themselves will help to foster
evolutionary improvements by defining generic principles
of risk assessment and focusing debate and empirical
research on these principles.
Furthermore, new public perceptions of risk occur, and
guidelines will evolve in response to these changes as
well. For example, attitudes about the practicality of
the outright elimination of carcinogenic risk as a regula-
tory goal have changed in the last decade. New methods
of quantitative risk assessment have developed, and public
discussions have increasingly focused on that field.
These changes can be expected to continue, so regular
periodic review of guidelines appears to be essential.
Such review should follow the same procedures recommended
for the initial guidelines, including ultimate agency
adoption af ter public comment.
RECOMMENDATION 8
l
The Committee recommends that guidelines initially be
developed, adopted, and applied for assessment of cancer
risks. Consideration of other types of health effects
should follow. It mav not vet be feasible to draw up as
complete a set of inference guidelines for some other
~ .
health effects. For these, def fining the extent of science
tif Sac knowledge and uncertainties and suggesting methods
for dealing with uncertainties would constitute a useful
f irst step.
OCR for page 170
170
The Committee believes that guidelines for carcinogenic
rise assessment should be drawn up first both because
cancer is perceived as a major public-health hazard and
because there is considerable experience with carcinogenic
Disk assessment from which to draw. Several guideline
documents for carcinogenic risk assessment have already
been produced, and review of these documents and of their
history should provide a useful point of departure.
Bowever, the other health effects that result from
exposure to hazardous substances are equally amenable to
prevention by regulatory action. Guidelines are desirable
for these types of effects, which include mutagenicity,
reproductive and teratogenic effects, neurotoxicity, and
behavioral changes. Less information (and, in some cases,
less knowledge of causal mechanisms) is usually available
on these effects. In fact, In some situations where the
knowledge base is less adequate than in cancer, stipulated
methods for handling scientific uncertainty may be even
more Important. Risk assessments for cancer are likely
more frequently to engage the problems of evaluating data
on exposure of experimental animals, whereas many other
health effects will require greater reliance on epidemio-
logic evidence.
The Committee believes that the absence of guidelines
for a health effect Is not a justification for agency
failure to perform risk assessments or to regulate on a
case-by-case basis.
RECOMMENDATION 9
Agencies should develop guidelines for exposure assess-
.
meet. Because of diverse problems in estimating different
._ .
means of exposure (e.q~, through food, drinking water,
and consumer Products), separate guidelines mav be needed
for each.
Operating assumptions are needed to estimate exposures
when direct measurements cannot be obtained. Examples of
cases in which such estimates would be important are the
projection of exposure to new chemicals and determination
of the exposure reduction that would result from ~mplemen-
tation of a particular control option. In Only a few
narrow cases (e.g., food additives) have general guide-
l~nes been developed for exposure assessment.
Although they are no less impor ant than techniques
for hazard identification and dose-response assessment,
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171
exposure assess...ent techniques have not been the subj ect
of major scientific debate and scrutiny. For example, if
exposure were known more accurately, priority-sett~ng for
testing new chemicals or for initiating regulation of one
of a group of chemicals could be organized on a more
rigorous basis; consideration of both the apparent potency
and the estimated exposure would be factored into such
decisions.
Exposure assessment guidelines that are uniform across
federal programs may not be feasible, because of the
diversity or media that must be addressed and the large
variation in exposures. Medium-specific exposure models
(such as dispersion models for air, water, and soil) are
used by programs in the agencies with various degrees of
sophistication and validation. Each agency or each prom
gram in an agency should develop mediumrspecific guide-
lines to stimulate evolutionary improvement, increase
consistency and predictability, and isolate the choice
among inference options from inappropriate risk manage-
ment considerations. Two or more programs that deal with
a given median of exposure should use the same guidelines.
Agencies should make their proposed exposure assess
ment guidelines available for public comment and should
subsequently issue final guidelines as established
procedures.
A CENTRAL BOARD ON RISE ASSESSME:NT }METHODS
RECOMME:NOATION 10
The Committee recommends to Congress that a Board on Risk
Assessment Methods be established to Perform the following
f unctions:
.
Of risk assessment and to make explicit the underlying
assl ~ tions and policy ramifications of the different
inference options in each component of the risk assess-
ment process.
.
.
To draft and periodically to revise recommended
inference guidelines for risk assessment for adoption and
use be federal regulatory agencies.
To study agency experience with risk assessment and
evaluate the usefulness of the Guidelines.
To identify research needs in the r isk assessment
field and in relevant underlying disciplines.
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172
To avoid possible misunderstanding of the role of the
Board, the Committee stresses the limitations on proposed
Board activities. The Board would not perform or review
individual risk assessments, nor would it adjudicate dis-
putes arising from regulatory actions related to specific
substances. Thus, the Board as envisioned would not per-
form functions contemplated by the ALEC proposal or H.R.
638. A central board of distinguished expert advisors is
not well-suited to such day-to-day responsibilities.
Furthermore, we believe strongly that it would be inappro-
priate to remove such essential analytic functions from
the responsible agencies and that it would be wasteful to
duplicate agency activities.
m e Board would make its contributions through discus-
sion of contending scientific positions, preparation of
recommended uniform guidelines, and fostering of advance-
ment of the field. It would fill a need for a prestigi-
ous, independent locus of activity for improving the
understanding of generic issues in both the scientific
basis and the federal practice of risk assessment.
Current ad hoc approaches too often color debate on
general issues with the implications for particular,
often contentious, risk management decisions. We expect
that Board activities would improve the scientific
performance of the agency processes and, in conjunction
with other mechanisms we recommend, achieve greater
objectivity and consistency and better public unde~stand-
ing of risk assessment. The Board would be the body to
which agencies, agency review panels, and others would
turn both for periodic recommendations of guideline
revisions and for information on the evolving art of
risk assessment.
Board Functions
-
We foresee four major functions for the Board. The first
two, scientific review and development of recommended
guidelines, would pursue the process described above for
ache initial generation of inference guidelines (Rec~en~
cation 7) . The deaf ting of guidelines by the Board would
ensure that guidelines benefit from the best available
scientific knowledge and judgment. After recommended
guidelines for a particular health effect were prepared
and referred to the agencies for review and adoption, the
Board would probably find it useful to continue its activ-
ity in the review of scientific developments relevant to
risk assessment for that effect.
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173
The Board's third function would involve observation
of and research into federal experience with risk assess-
ment generally and review or the usefulness of guidelines.
A major purpose would be to acquaint the Board with ways
of improving the guidelines in later periodic reviews.
As a fourth function, the Board would identify the key
scientif ic research needs in health risk assessment.
Preparation of guidelines would put the Board in an ideal
position to understand which of the many inference options
needed to cover gaps in scientific understanding are most
important and are amenable to study. The policy difficul-
ties in regulating chronic health hazards can be resolved
only if uncertainty in the scientific basis of assessments
i s reduced. Board activities could take such forms as
advising funding agencies on research priorities, c~mmis-
s~oning survey papers to synthesize recent scientific
findings, and sponsoring conferences or special publica-
tions on particularly apt scientific questions or on
matters that are important to risk assessment, but have
been neglected by the scientif ic commune ty. In addition,
the Board's experience would place it in an ideal posi-
tzon to assess whether and how toxicologic research on
part~cu' ar chemicals could be better tailored to the
analytic needs of future risk assessors. For example,
many current testing procedures were designed for the
narrow purpose of hazard identification, and adjustments
in these procedures could lead to more definitive dose-
r esponse assessments.
The Committee believes that the responsibilities of
the Board could be discharged by a group of volunteer
experts that convened monthly for 1-2 days.
Organizational Placement
The proper placement of the Board would be crucial to its
prospects for success. There are four criteri a for
identifying appropriate locations: professional
excellence, facility with studies having substantial
policy ratifications, permanence, and independence.
Professional excellence is Important because the
Board's recommended guidelines, as well as its other
work, should be based on the best available science; the
Board should be able to attract the best talent in the
nation. Facility with difficult policy issues is ~mpor-
tant because risk assessment is not a strictly scientific
undertaking, and it would be crucial for the Board to
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174
conduct its work competently and with full understanding
of the policy process. Placement in a permanent, existing
organization is advisable because the Board should be
able to begin its work quickly and remain stable in order
to conduct periodic revisions of guidelines. Independence
is needed to provide credibility; work that is suspected
of bias will not transcend the current atmosphere of dis-
trust. We see advantages in placing the Board outside
the government. In particular, the Board should be ante
to draw on the widest poor OF Scientific ex~:Lu~ all - ~~-
be restricted to government scientists; placement in the
government might hinder the perception that the Board Is
free from the policy orientation of the administration in
power; and direct invol~r-~nent by the regulatory agencies
themselves could detract from their ability to make regu-
~atory decisions while the guidelines were in preparation.
The Committee has evaluated a number of possible
organizational bases for the Board. The National Toxi-
cology Program has had relevant experience with the
c~imntifin Basis oF risk assessment, but it already has
major responsibility for coordinating testing of chemi-
cals of interest to regulatory agencies. The Congres-
szonal Office of Technology Assessment is another
possibility. Bowever, the governance of the Office of
Technology Assessment by a board composed of members of
_
Congress could prove a practical impediment to the
production of guidelines. Guidelines would clearly have
Policy ramifications that may be at variance with the
established policy positions of OTA board members. The
Office of Science and Technology Policy or the Office of
Management and Budget could provide government-wide
coordination; both are in the Executive Office of the
President and are well positioned to ensure agency
response and uniform implementation of guidelines and
over Board findings. The major disadvantage of location
in the Executive Office of the President is the lack of
independence and, consequently, the greater likelihood of
mixing scientific and policy considerations. All these
organizations share the major drawback that they are in
the goverrment.
A special—purpose national (or Presidential) co~is-
sion on risk assessment methods could attract eminent
scientists to service and could be designed to balance
viewpoints, but would lack permanence and policy experi-
ence. Professional societies constitute another class of
possible candidates, but they generally have limited
familiarity with policy studies.
.
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175
We conclude that the National Academy of Sciences-
National Research Council meets the four criteria for
placement. The ALEC proposal addressed the some general
concerns that have occupied this Committee and concluded
that the most appropriate locus for the central panel was
in the NAS-N~C. Although we do not concur in the idea of
centralizing the performance of risk assessments, the
arguments presented by the AIEC propose' for the selection
of the NAS-~RC are fully applicable to the question of
the placement of a Board that would address generic scienr
tific issues in risk assessment. We believe that the
Board could best function under ~AS-N~ auspices, if the
NAS-NRC agreed to provide them, and would be of great
value In achieving many of the goals that we share with
the authors of the ATEC proposal and of B.R. 638. Current
NAS-N~C procedures for establishing, managing, and issuing
study reports are appropriate for the prospective Board.
Qualifications of Sobers
We recommend that the Board consist of scientists with
training and experience in the various disciplines
involved in the process of risk assessment, including
biostatistics, toxicology, epidemiology, environmental
engineering, and clinical medicine. Other relevant
fields--such as law, ethics, and the social sciences--
should be included to ensure due apprec cation of the
policy context of Board activities. For the same reason,
some members should have familiarity with regulatory
programs. The nomination and selection of members should
be in accordance with established NAS-NBC procedures.
Service might be for staggered 3-year periods.
Sunset Review
The entire concept of the Board and its functions should
be reviewed after approximately 6-8 years.
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Representative terms from entire chapter:
inference options
