9
Toward Improved Risk-Based Decision-Making

The Framework for Risk-Based Decision-Making is designed to improve risk assessment by enhancing the value of risk assessment to policy-makers, expanding stakeholder participation, and more fully informing the public, Congress, and the courts about the basis of Environmental Protection Agency (EPA) decisions. That will require building on EPA’s decision-making practices to expand consideration of options and developing a long-term strategy for renewal. To shape such a strategy, this chapter identifies three categories of prerequisites of successful transition to the framework:

  • Adopting transition rules. The most successful experiences and practices that govern current risk assessment and risk-management decision-making in EPA and other institutions offer models for introducing agency leaders and staff to new issues and processes and for integrating new principles and practices into the framework outlined in Chapter 8.

  • Managing institutional processes. Management issues include consideration of legal impediments to implementing the framework, changes in organizational structure, and strengthening institutional capacity, for example, skills, training and other forms of knowledge-building, and resources.

  • Providing leadership and management. The transition will require support, including guidance and resources, from the EPA leadership community, the executive and legislative branches of government, and key stakeholders.

Those and related implementation recommendations signify the committee’s recognition that assembling, evaluating, and interpreting information called for in the framework introduce major changes in EPA’s various risk-assessment and decision-making processes. Some aspects of the framework (for example, new approaches to communication and participation) may not require major new investment in the short term; however, for an institution as large and diverse as EPA, the availability and allocation of resources—funding, time, and personnel—are central aspects of sustaining any institutional arrangements for agencywide



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9 Toward Improved Risk-Based Decision-Making The Framework for Risk-Based Decision-Making is designed to improve risk assess- ment by enhancing the value of risk assessment to policy-makers, expanding stakeholder participation, and more fully informing the public, Congress, and the courts about the basis of Environmental Protection Agency (EPA) decisions. That will require building on EPA’s decision-making practices to expand consideration of options and developing a long-term strategy for renewal. To shape such a strategy, this chapter identifies three categories of prerequisites of successful transition to the framework: • Adopting transition rules. The most successful experiences and practices that govern current risk assessment and risk-management decision-making in EPA and other institutions offer models for introducing agency leaders and staff to new issues and processes and for integrating new principles and practices into the framework outlined in Chapter 8. • Managing institutional processes. Management issues include consideration of le- gal impediments to implementing the framework, changes in organizational structure, and strengthening institutional capacity, for example, skills, training and other forms of knowl- edge-building, and resources. • Proiding leadership and management. The transition will require support, including guidance and resources, from the EPA leadership community, the executive and legislative branches of government, and key stakeholders. Those and related implementation recommendations signify the committee’s recognition that assembling, evaluating, and interpreting information called for in the framework intro- duce major changes in EPA’s various risk-assessment and decision-making processes. Some aspects of the framework (for example, new approaches to communication and participa- tion) may not require major new investment in the short term; however, for an institution as large and diverse as EPA, the availability and allocation of resources—funding, time, and personnel—are central aspects of sustaining any institutional arrangements for agencywide 28

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2 TOWARD IMPROVED RISK-BASED DECISION-MAKING change of the magnitude outlined in Chapter 8.1 As in all enterprises, funding is a rate-limit- ing and quality-determining step. TRANSITION TO THE FRAMEWORk FOR RISk-bASED DECISION-MAkINg Improving the utility of risk assessment to include upfront problem formulation and scoping and planning with an expanded array of options requires several practical steps to ensure that risk assessors and risk managers have a clear understanding of their roles and responsibilities and have sufficient guidance to administer them effectively. As a beginning, EPA should examine the key functions and attributes of its decision-making processes in relation to those recommended in this report. Although many activities are comparable (for example, hazard assessment and dose-response assessment), others, such as life-cycle assess- ment, will be new in many agency programs and will need to be integrated into the process of assessing risks and the options for managing them. Historically, even though EPA risk assessment is generally linked to decision-making, guidance arising out of National Research Council risk-assessment reports has been directed mainly to improving agency risk assessments with little attention to future decision-mak- ing. The framework focuses attention on improving the utility of risk assessments to better inform decision-making. To implement the framework, the agency will need innoatie and instructie guidance that informs its scientists, economists, lawyers, regulatory staff, senior managers, and policy makers of their roles and, most important, fosters interaction among them. Principles, examples, and practices drawn from “success stories” in which EPA and other entities have used processes similar to those proposed for the framework offer starting points for such guidance. Selected risk-based decision-making scenarios that provide realistic illustrations of how the framework can work can be especially instructive. The framework promotes greater attention to and use of risk-related information from such fields as economics, psychology, and sociology—disciplines not usually involved to a great extent in EPA assessments. While those fields may not be central in the risk assessment itself, the framework integrates a variety of information in constructing risk-management decisions. Increased emphasis on those fields in the framework requires extending the kind of robust peer-review practices historically required by statute or policy for risk assessment to cost and benefit analyses, community impact assessments, life-cycle analyses, and related information.2 The objective would be to give decision-makers, stakeholders, and the public confidence in, and understanding of, the insights and limitations of evaluations. Improved peer review of analyses will also add an important dimension of transparency. INSTITUTIONAL PROCESSES The framework presents opportunities for EPA to review and realign some institutional processes to foster consistent approaches to using risk assessment and other analyses (in- 1 This committee comment is prompted by recent congressional testimony on the impact of budget cuts on EPA’s capacity to meet the demands of risk assessment as currently practiced (Renner 2007). The budget cuts generate serious concern about the agency’s capacity to undertake the advanced analyses recommended in this report and to implement a new, more data-intensive framework without concerted attention to funding and staffing as part of governmentwide and EPA strategic planning and annual budget processes. 2 As in traditional risk assessment, peer reviewers would be experts in the discipline under review—sociolo- gists for societal impacts, economists for economic impacts, and so on. However, especially valuable would be the addition of peer reviewers, expert in multiple disciplines, that can evaluate the risk and benefit-cost analyses that inform different decision options.

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260 SCIENCE AND DECISIONS: ADVANCING RISK ASSESSMENT cluding technical and economic) to better inform risk-management decisions across EPA’s various programs. Several processes warrant consideration. Statutory Authority The committee believes that it has achieved its goal of recommending substantial im- provements that can be accomplished by refining and refocusing institutional processes with- in existing statutory authority. Committee recommendations for expanding risk-assessment activities to give more emphasis to, for example, cumulative risk, quantitative uncertainty and variability analysis, and harmonizing analyses for cancer and noncancer end points call for state-of-the-science improvements that easily fall within the agency’s existing authority: for more than 20 years, EPA has regularly incorporated state-of-the-science improvements of this kind to develop and amend general risk-assessment guidelines and conduct individual assessments. The committee’s more far-reaching recommendations—such as broad-based discussion of risk-management options early in the process, extensive stakeholder participation through- out the process, and consideration of life-cycle approaches in a broader array of agency programs—can be viewed as common-sense extensions throughout the agency as a whole of practices that are now limited to selected programs or are unevenly and incompletely implemented. For example, EPA’s Guidelines for Ecological Risk Assessment contemplates the kind of options-informed risk-assessment planning envisioned by the framework (EPA 1998, p. 10): Risk assessors and risk managers both consider the potential value of conducting a risk as- sessment to address identified problems. Their discussion explores what is known about the degree of risk, what management options are aailable to mitigate or preent it, and the value of conducting a risk assessment compared with other ways of learning about and addressing environmental concerns [emphasis added]. Focused attention on integrated agencywide implementation of that and other existing guidance related to cumulative risk assessment, criteria for departing for defaults, and life- cycle analysis would lead to some of the improvements contemplated by the framework without new legislative initiatives. Structural Change In keeping with EPA’s media-based organizational structure, agency decision-making processes are compartmentalized in line with media- and statute-specific environmental prob- lems, legal requirements, case law, and programmatic history. This approach parallels EPA statutes but takes little cognizance of current understanding of the multimedia, cumulative- risk characteristics of environmental pollution and the need for multidisciplinary, cross-pro- gram, and cross-agency analyses of scientific issues and regulatory options. The committee’s major recommendation that EPA move to a consistent and transparent process that ensures the right questions are being asked of the assessment will therefore require new approaches to coordination, communication, and framing of environmental-protection options. To adapt its current decision-making process to the framework, EPA should establish an options-development team composed of Senior Executive Service environmental profession- als from the major regulatory programs, the Office of Environmental Information, the Office of General Counsel, the Office of Research and Development, and other relevant offices. The team’s primary responsibilities would include identifying prospective decisions (or categories

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261 TOWARD IMPROVED RISK-BASED DECISION-MAKING of decisions) for which risk assessments will be needed and providing risk assessors with contextual information on the problem under review and the regulatory or other options then3 under consideration. To provide guidance for EPA risk assessors and managers and information for stakeholders and the public, essential team functions would include • Developing criteria for defining and selecting high-priority risk assessments for continuing attention by the team. • Defining a suite of preliminary decision-making options that identify critical factors and suggest bounds for individual risk assessments. • Providing an explicit statement of the problem that the agency is attempting to solve. • Ensuring consideration of risk tradeoffs. • Maintaining a system for tracking accountability in the preparation of individual risk assessments and the options-development process’s contribution to and impact on the use of each assessment in decision-making. The options-informed process recommended in this report recognizes both regulatory and nonregulatory options and gives EPA the flexibility to define options narrowly or broadly, depending on the nature and extent of the problem to be solved. The nature and scope of the options can be expected to vary from one problem to the next. Skills, Training, and knowledge-building Many risk assessments involve a complex, data-intensive, and multidisciplinary analyses. The data come from studies on highly inbred laboratory animals and from genetically diverse human populations, and basic monitoring data come from environmental media and sophis- ticated analyses of biochemical mechanisms, cancer pathology, and exposure pathways. Such analyses demand a multidisciplinary and scientifically sophisticated workforce, experienced not only in the underlying disciplines but in special aspects of the risk-assessment process. Quantitative uncertainty analysis and cumulative risk assessment, for example, may well require expertise not now available in EPA or the larger scientific community in the numbers and experience levels needed to implement recommendations in this report. As a result, imple- menting many committee recommendations will require new expertise, and EPA may need to expand its programs to draw on expertise in other federal agencies and private entities. In all cases, training will be necessary on a continuing basis to ensure that staff are conversant with advances in disciplines that contribute to risk assessment and decision-making. Training of managers and decision-makers on risk-assessment issues is essential for the assessor-manager discussion at the core of problem formulation and scoping, planning, and subsequent decision-making. Those senior participants in the process can participate fully and knowledgeably only if they are conversant with risk-assessment issues and methods. Such training is also essential for communication between senior agency officials, stakeholders, and other members of the public. It is equally important for technical staff to be trained to understand and appreciate the nontechnical factors that shape some risk-management and decision-making issues. 3 As discussed in Chapter 3, the iterative nature of the overall process calls for continuing evaluation of options as a risk assessment proceeds. The initial set of options can therefore be expected to evolve through revision, dele- tion, and addition.

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262 SCIENCE AND DECISIONS: ADVANCING RISK ASSESSMENT LEADERSHIP AND MANAgEMENT Because the development of the framework has agencywide application, it is critical for the EPA top-leadership to participate in the development and implementation of the framework. The leadership and participation by the EPA administrator and assistant admin- istrators, Congress, other arms of the executive branch (for example, the Office of Science and Technology Policy, the White House, and the Office of Management and Budget), and major stakeholders, including other federal agencies, will be essential for improvements in EPA’s decision-making processes. In this context, leadership attention to several management objectives will be critical: • Developing explicit policies that commit EPA to implementing an options-informed process for risk assessment and risk management. • Funding to implement these policies, including budgets adequate for preparing guid- ance and other documents, for training to prepare EPA personnel to undertake implementa- tion activities, and for developing an expanded knowledge base and institutional capacity for more timely results. • Adopting a common set of evaluation factors—applicable to all programs—for as- sessing the outcomes of policy decisions and the efficacy of the framework. Other activities can advance the agency’s implementation program. Ideally, the program would include a system of workshops for managers and staff to create a learning culture that emphasizes acquiring new knowledge, professional development, and decision-making practices and tools aimed at effective problem-solving. In this regard, a serious commitment to a consistent process for implementing the framework would include evaluating senior managers, in part, on the pace and success of applying new principles and practices in in- dividual programs. Committed leadership would also pursue opportunities for partnerships and cooperative relationships with stakeholder organizations to expand the universe of op- tions for problem-solving beyond traditional regulation. In summary, informed and, in some cases, ground-breaking governance are intended to improve EPA risk-assessment processes, focus the assessment on the relevant questions, discourage political interference or pre-determined policy biases, and promote senior-level oversight of the timeliness, relevance, and impact of decision-making. The present report presents a major opportunity for EPA to re-examine its decision-making processes, innovate reforms, and expedite change that takes account of 21st century scientific developments, the faster pace of the global marketplace, and the needs of contemporary policy-making. CONCLUSIONS AND RECOMMENDATIONS The committee was given a broad charge to develop scientific and technical recommenda- tions for improving risk-analysis approaches used by EPA. In its evaluation, the committee focused on the scientific underpinnings of risk assessment and its role in decision-making. Risk assessment is at a crossroads, and the credibility of this essential tool is being challenged by stakeholders who have the potential to gain or lose from the outcome of an assessment. Although there appears to be an expanding need for risk-based decisions, the science underlying risk assessment and the decision contexts in which risk assessments are being used are increasingly complex, and the value and relevance of risk assessment are being questioned. The context of risk decisions has evolved since the development of the framework in the 1983 National Research Council report Risk Assessment in the Federal Goernment:

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263 TOWARD IMPROVED RISK-BASED DECISION-MAKING Managing the Process (NRC 1983), known as the Red Book, and challenges now often include broad consideration of multiple health and ecologic effects, costs and benefits, and risk-risk tradeoffs. The growing complexity of the process is compounded by the ever-chang- ing nature of the science underlying many of the assumptions concerning measurement of adverse effects, exposures, dose and response, and uncertainty in the characterization of risks. As the science has advanced, so has the need to consider the social impacts of risk decisions to ensure that risk assessment is relevant to stakeholder concerns. The following conclusions and recommendations aim to provide guidance to improve the scientific and technical basis of risk estimates, to address the characterization of vari- ability and uncertainty, and ultimately to broaden the focus of risk analysis toward the development of improved public-health and environmental decisions. Implementation of the committee’s recommendations will help to ensure that risk assessments are consistent with current and evolving scientific understanding and relevant to the various risk-management missions of EPA. Design of Risk Assessment The process of planning risk assessment and ensuring that its level and complexity are consistent with the needs to inform decision-making can be thought of as the “design” of risk assessment. The committee encourages EPA to focus greater attention on design in the formative stages of risk assessment, specifically on planning and scoping and problem formulation, as articulated in EPA guidance for ecologic and cumulative risk assessment (EPA 1998, 2003). Good design involves bringing risk managers, risk assessors, and various stakeholders together early in the process to determine the major factors to be considered, the decision-making context, and the timeline and depth needed and to ensure that the right questions are being asked in the context of the assessment. Increased emphasis on planning and scoping and on problem formulation has been shown to lead to risk assessments that are more useful and better accepted by decision-makers (EPA 2002, 2003, 2004); however, incorporation of these stages in risk assessment has been inconsistent, as noted by their absence from various EPA guidance documents (EPA 2005a, b). An important element of planning and scoping is definition of a clear set of options for consideration in decision-making where appropriate. This should be reinforced by the up- front involvement of decision-makers, stakeholders, and risk assessors, who together can evaluate whether the design of the assessment will address the identified problems. Recommendation: Increased attention to the design of risk assessment in its formative stages is needed. The committee recommends that planning and scoping and problem formulation, as articulated in EPA guidance documents (EPA 1998, 2003), should be formalized and implemented in EPA risk assessments. Uncertainty and variability Addressing uncertainty and variability is critical for the risk-assessment process. Un- certainty stems from lack of knowledge, so it can be characterized and managed but not eliminated. Uncertainty can be reduced by the use of more or better data. Variability is an inherent characteristic of a population, inasmuch as people vary substantially in their ex- posures and their susceptibility to potentially harmful effects of the exposures. Variability cannot be reduced, but it can be better characterized with improved information. There have been substantial differences among EPA’s approaches to and guidance for

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264 SCIENCE AND DECISIONS: ADVANCING RISK ASSESSMENT addressing uncertainty in exposure and dose-response assessment. EPA does not have a con- sistent approach to determine the level of sophistication or the extent of uncertainty analysis needed to address a particular problem. The level of detail for characterizing uncertainty is appropriate only to the extent that it is needed to inform specific risk-management deci- sions appropriately. It is important to address the required extent and nature of uncertainty analysis in the planning and scoping phases of a risk assessment. Inconsistencies in the treat- ment of uncertainty among components of a risk assessment can make the communication of overall uncertainty difficult and sometimes misleading. Variability in human susceptibility has not received sufficient or consistent attention in many EPA health risk assessments although there are encouraging exceptions, such as those for lead, ozone, and sulfur oxides. For example, although EPA’s 2005 Guidelines for Car- cinogen Risk Assessment (EPA 2005a) acknowledges that susceptibility can depend on one’s stage in life, this requires greater attention in practice, particularly for specific population groups that may have greater susceptibility because of their age, ethnicity, or socioeconomic status. The committee encourages EPA to move toward the long-term goal of quantifying population variability more explicitly in exposure assessment and dose-response relation- ships. An example of progress that moves towards this goal is EPA’s draft risk assessment of trichloroethylene (EPA 2001; NRC 2006), which considers how differences in metabolism, disease, and other factors contribute to human variability in response to exposures. Recommendation: EPA should encourage risk assessments to characterize and commu- nicate uncertainty and variability in all key computational steps of risk assessment—for example, exposure assessment and dose-response assessment. Uncertainty and variability analysis should be planned and managed to reflect the needs for comparative evalua- tion of the risk-management options. In the short term EPA, should adopt a “tiered” approach for selecting the level of detail to be used in the uncertainty and variability assessments, and this should be made explicit in the planning stage. To facilitate the characterization and interpretation of uncertainty and variability in risk assessments, EPA should develop guidance to determine the appropriate level of detail needed in un- certainty and variability analyses to support decision-making and should provide clear definitions and methods for identifying and addressing different sources of uncertainty and variability. Selection and Use of Defaults Uncertainty is inherent in all stages of risk assessment, and EPA typically relies on as- sumptions when chemical-specific data are not available. The 1983 Red Book recommended the development of guidelines to justify and select from among the available inference op- tions, the assumptions—now called defaults—to be used in agency risk assessments to ensure consistency and avoid manipulations in the risk-assessment process. The committee acknowl- edges EPA’s efforts to examine scientific data related to defaults (EPA 1992, 2004, 2005a), but recognizes that changes are needed to improve the agency’s use of them. Much of the scientific controversy and delay in completion of some risk assessments has stemmed from the long debates regarding the adequacy of the data to support a default or an alternative approach. The committee concludes that established defaults need to be maintained for the steps in risk assessment that require inferences and that clear criteria should be available for judging whether, in specific cases, data are adequate for direct use or to support an inference in place of a default. EPA, for the most part, has not yet published clear, general guidance on what level of evidence is needed to justify use of agent-specific data and not resort to a

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26 TOWARD IMPROVED RISK-BASED DECISION-MAKING default. There are also a number of defaults (missing or implicit defaults) that are engrained in EPA risk-assessment practice but are absent from its risk-assessment guidelines. For ex- ample, chemicals that have not been examined sufficiently in epidemiologic or toxicologic studies are often insufficiently considered in or are even excluded from risk assessments; because no description of their risks is included in the risk characterization, they carry no weight in decision-making. That occurs in Superfund-site and other risk assessments, in which a relatively short list of chemicals on which there are epidemiologic and toxicologic data tends to drive the exposure and risk assessments. Recommendation: EPA should continue and expand use of the best, most current science to support and revise default assumptions. EPA should work toward the development of explicitly stated defaults to take the place of implicit defaults. EPA should develop clear, general standards for the level of evidence needed to justify the use of alternative assumptions in place of defaults. In addition, EPA should describe specific criteria that need to be addressed for the use of alternatives to each particular default assumption. When EPA elects to depart from a default assumption, it should quantify the implications of using an alternative assumption, including how use of the default and the selected alternative influences the risk estimate for risk-management options under consideration. EPA needs to more clearly elucidate a policy on defaults and provide guidance on its implementation and on evaluation of its impact on risk decisions and on efforts to protect the environment and public health. A Unified Approach to Dose-Response Assessment A challenge to risk assessment is to evaluate risks in ways that are consistent among chemicals, that account adequately for variability and uncertainty, and that provide informa- tion that is timely, efficient, and maximally useful for risk characterization and risk manage- ment. Historically, dose-response assessments at EPA have been conducted differently for cancer and noncancer effects, and the methods have been criticized for not providing the most useful results. Consequently, noncancer effects have been underemphasized, especially in benefit-cost analyses. A consistent approach to risk assessment for cancer and noncancer effects is scientifically feasible and needs to be implemented. For cancer, it has generally been assumed that there is no dose threshold of effect, and dose-response assessments have focused on quantifying risk at low doses and estimating a population risk for a given magnitude of exposure. For noncancer effects, a dose threshold (low-dose nonlinearity) has been assumed, below which effects are not expected to occur or are extremely unlikely in an exposed population; that dose is a reference dose (RfD) or a reference concentration (RfC)—it is thought “likely to be without an appreciable risk of deleterious effects” (EPA 2002). EPA’s treatment of noncancer and low-dose nonlinear cancer end points is a major step by the agency in an overall strategy to harmonize cancer and noncancer approaches to dose- response assessment; however, the committee finds scientific and operational limitations in the current approaches. Noncancer effects do not necessarily have a threshold, or low-dose nonlinearity, and the mode of action of carcinogens varies. Background exposures and under- lying disease processes contribute to population background risk and can lead to linearity at the population doses of concern. Because the RfD and RfC do not quantify risk for different magnitudes of exposure but rather provide a bright line between possible harm and safety, their use in risk-risk and risk-benefit comparisons and in risk-management decision-making

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266 SCIENCE AND DECISIONS: ADVANCING RISK ASSESSMENT is limited. Cancer risk assessments usually do not account for differences among humans in cancer susceptibility other than possible differences in early-life susceptibility. Scientific and risk-management considerations both support unification of cancer and noncancer dose-response assessment approaches. The committee therefore recommends a consistent, unified approach for dose-response modeling that includes formal, systematic assessment of background disease processes and exposures, possible vulnerable populations, and modes of action that may affect a chemical’s dose-response relationship in humans. That approach redefines the RfD or RfC as a risk-specific dose that provides information on the percentage of the population that can be expected to be above or below a defined accept- able risk with a specific degree of confidence. The risk-specific dose will allow risk managers to weigh alternative risk options with respect to that percentage of the population. It will also permit a quantitative estimate of benefits for different risk-management options. For example, a risk manager could consider various population risks associated with exposures resulting from different control strategies for a pollution source and the benefits associated with each strategy. The committee acknowledges the widespread applications and public- health utility of the RfD; the redefined RfD can still be used as the RfD has been to aid risk-management decisions. Characteristics of the committee’s recommended unified dose-response approach include use of a spectrum of data from human, animal, mechanistic, and other relevant studies; a probabilistic characterization of risk; explicit consideration of human heterogeneity (includ- ing age, sex, and health status) for both cancer and noncancer end points; characterization (through distributions to the extent possible) of the most important uncertainties for cancer and noncancer end points; evaluation of background exposure and susceptibility; use of probabilistic distributions instead of uncertainty factors when possible; and characterization of sensitive populations. The new unified approach will require implementation and development as new chemi- cals are assessed or old chemicals are reassessed, including the development of test cases to demonstrate proof of concept. Recommendation: The committee recommends that EPA implement a phased-in ap- proach to consider chemicals under a unified dose-response assessment framework that includes a systematic evaluation of background exposures and disease processes, possible vulnerable populations, and modes of action that may affect human dose-response rela- tionships. The RfD and RfC should be redefined to take into account the probability of harm. In developing test cases, the committee recommends a flexible approach in which different conceptual models can be applied in the unified framework. Cumulative Risk Assessment EPA is increasingly asked to address broader public-health and environmental-health questions involving multiple exposures, complex mixtures, and vulnerability of exposed populations—issues that stakeholder groups (such as communities affected by environmental exposures) often consider to be inadequately captured by current risk assessments. There is a need for cumulative risk assessments as defined by EPA (EPA 2003)—assessments that include combined risks posed by aggregate exposure to multiple agents or stressors; aggre- gate exposure includes all routes, pathways, and sources of exposure to a given agent or stressor. Chemical, biologic, radiologic, physical, and psychologic stressors are considered in this definition (Callahan and Sexton 2007). The committee applauds the agency’s move toward the broader definition in making

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26 TOWARD IMPROVED RISK-BASED DECISION-MAKING risk assessment more informative and relevant to decisions and stakeholders. However, in practice, EPA risk assessments often fall short of what is possible and is supported by agency guidelines in this regard. Although cumulative risk assessment has been used in various con- texts, there has been little consideration of nonchemical stressors, vulnerability, and back- ground risk factors. Because of the complexity of considering so many factors simultaneously, there is a need for simplified risk-assessment tools (such as databases, software packages, and other modeling resources) that would allow screening-level risk assessment and could allow communities and stakeholders to conduct assessments and thus increase stakeholder participation. Cumulative human health risk assessment should draw greater insights from ecologic risk assessment and social epidemiology, which have had to grapple with similar issues. A recent National Research Council report on phthalates addresses issues related to the framework within which dose-response assessment can be conducted in the context of simultaneous exposures to multiple stressors (NRC 2008). Recommendation: EPA should draw on other approaches, including those from ecologic risk assessment and social epidemiology, to incorporate interactions between chemical and nonchemical stressors in assessments; increase the role of biomonitoring, epide- miologic, and surveillance data in cumulative risk assessments; and develop guidelines and methods for simpler analytical tools to support cumulative risk assessment and to provide for greater involvement of stakeholders. In the short-term, EPA should develop databases and default approaches to allow for incorporation of key nonchemical stress- ors in cumulative risk assessments in the absence of population-specific data, considering exposure patterns, contributions to relevant background processes, and interactions with chemical stressors. In the long-term, EPA should invest in research programs related to interactions between chemical and nonchemical stressors, including epidemiologic investigations and physiologically based pharmacokinetic modeling. Improving the Utility of Risk Assessment Given the complexities of the current problems and potential decisions faced by EPA, the committee grappled with designing a more coherent, consistent, and transparent pro- cess that would provide risk assessments that are relevant to the problems and decisions at hand and that would be sufficiently comprehensive to ensure that the best available options for managing risks were considered. To that end, the committee proposes a framework for risk-based decision-making (see Figure 9-1). The framework consists of three phases: I, enhanced problem formulation and scoping, in which the available risk-management op- tions are identified; II, planning and assessment, in which risk-assessment tools are used to determine risks under existing conditions and under potential risk-management options; and III, risk management, in which risk and nonrisk information is integrated to inform choices among options. The framework has at its core the risk-assessment paradigm (stage 2 of phase II) estab- lished in the Red Book (NRC 1983). However, the framework differs from the Red Book paradigm, primarily in its initial and final steps. The framework begins with a “signal” of potential harm (for example, a positive bioassay or epidemiologic study, a suspicious disease cluster, or findings of industrial contamination). Under the traditional paradigm, the ques- tion has been, What are the probability and consequence of an adverse health (or ecologic) effect posed by the signal? In contrast, the recommended framework asks, implicitly, What options are there to reduce the hazards or exposures that have been identified, and how can risk assessment be used to evaluate the merits of the various options? The latter question

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PHASE I: PHASE II: PHASE III: 268 PROBLEM FORMULATION PLANNING AND CONDUCT RISK MANAGEMENT AND SCOPING OF RISK ASSESSMENT Stage 1: Planning • For the given decision context, what are the attributes of assessments necessary to characterize risks of existing conditions and the effects on risk of proposed options? What level of uncertainty and variability analysis is appropriate? • What are the relative health or • What problems are environmental benefits of the associated with existing proposed options? environmental conditions? Stage 2: Risk Assessment • How are other decision- • If existing conditions appear making factors (technologies, to pose a threat to human or • Hazard Identification costs) affected by the proposed environmental health, what What adverse health or environmental effects options? options exist for altering those are associated with the agents of concern? conditions? • What is the decision, and its • Risk Characterization justification, in light of benefits, • Dose-Response Assessment • Under the given decision costs, and uncertainties in each context, what risk and other What is the nature and For each determining adverse effect, what is the option? technical assessments are magnitude of risk associated relationship between dose and the probability of necessary to evaluate the with existing conditions? • How should the decision be the occurrence of the adverse effect in the range possible risk-management communicated? of doses identified in the exposure assessment? options? What risk decreases (benefits) are associated with each of the • Is it necessary to evaluate the options? effectiveness of the decision? Are any risks increased? What • Exposure Assessment • If so, how should this be done? are the significant uncertainties? What exposures/doses are incurred by each population of interest under existing conditions? How does each option affect existing conditions and resulting exposures/doses? Stage 3: Confirmation of Utility • Does the assessment have the attributes called for in planning? NO YES • Does the assessment provide sufficient information to discriminate among risk- management options? • Has the assessment been satisfactorily peer reviewed? FORMAL PROVISIONS FOR INTERNAL AND EXTERNAL STAKEHOLDER INVOLVEMENT AT ALL STAGES • The involvement of decision-makers, technical specialists, and other stakeholders in all phases of the processes leading to decisions should in no way compromise the technical assessment of risk, which is carried out under its own standards and guidelines. FIgURE 9-1 A framework for risk-based decision-making that maximizes8-1.eps of risk assessment. Figure the utility landscape

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269 toward improved risk-based decision-making focuses on the risk-management options (or interventions) designed to provide adequate public-health and environmental protection and to ensure well-supported decision-mak- ing. Under this framework, the questions posed arise from early and careful planning of the types of assessments (including risks, costs, and technical feasibility) and the required level of scientific depth that are needed to evaluate the relative merits of the options being considered. Risk management involves choosing among the options after the appropriate assessments have been undertaken and evaluated. The framework begins with enhanced problem formulation and scoping (phase I), in which risk-management options and the types of technical analyses, including risk assess- ments, needed to evaluate and discriminate among the options are identified. Phase II consists of three stages: planning, risk assessment, and confirmation of utility. Planning (stage 1) is done to ensure that the level and complexity of risk assessment (including uncertainty and variability analysis) are consistent with the goals of decision-making. After risk assessment (stage 2), stage 3 evaluates whether the assessment was appropriate and whether it allows discrimination among the risk-management options. If the assessment is not determined to be adequate, the framework calls for a return to planning (phase II, stage 1). Otherwise, phase III (risk management) is undertaken: the relative health or environmental benefits of the proposed risk-management options are evaluated for the purpose of reaching a decision. The framework systematically identifies problems and options that risk assessors should evaluate at the earliest stages of decision-making. It expands the array of impacts assessed beyond individual effects (for example, cancer, respiratory problems, and individual species) to include broader questions of health status and ecosystem protection. It provides a formal process for stakeholder involvement throughout all stages but has time constraints to en- sure that decisions are made. It increases understanding of the strengths and limitations of risk assessment by decision-makers at all levels, for example, by making uncertainties and choices more transparent. The committee is mindful of concerns about political interference in the process, and the framework maintains the conceptual distinction between risk assessment and risk man- agement articulated in the Red Book. It is imperative that risk assessments used to evalu- ate risk-management options not be inappropriately influenced by the preferences of risk managers. With a focus on early and careful planning and problem formulation and on the options for managing the problem, implementation of the framework can improve the utility of risk assessment for decision-making. Although some aspects of the framework are achievable in the short term, its full implementation will require a substantial transition period. EPA should phase in the framework with a series of demonstration projects that apply it and that determine the degree to which it meets the needs of the agency risk managers, how risk-management conclusions differ as a result of its application, and the effectiveness of measures to ensure that risk managers and policy-makers do not inappropriately influence the scientific conduct of risk assessments. Recommendation: To make risk assessments most useful for risk-management deci- sions, the committee recommends that EPA adopt a framework for risk-based decision- making (see Figure 9-1) that embeds the Red Book risk-assessment paradigm into a process with initial problem formulation and scoping, upfront identification of risk- management options, and use of risk assessment to discriminate among these options.  he committee notes that not all decisions require or are amenable to risk assessment and that in most cases T one of the options explicitly considered is “no intervention.”

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20 SCIENCE AND DECISIONS: ADVANCING RISK ASSESSMENT Stakeholder Involvement Many stakeholders believe that the current process for developing and applying risk as- sessments lacks credibility and transparency. That may be partly because of failure to involve stakeholders adequately as active participants at appropriate points in the risk-assessment and decision-making process rather than as passive recipients of the results. Previous Na- tional Research Council and other risk-assessment reports (NRC 1996; PCCRARM 1997) and comments received by the committee (Callahan 2007; Kyle 2007) echo such concerns. The committee agrees that greater stakeholder involvement is necessary to ensure that the process is transparent and that risk-based decision-making proceeds effectively, efficiently, and credibly. Stakeholder involvement needs to be an integral part of the risk-based deci- sion-making framework, beginning with problem formulation and scoping. Although EPA has numerous programs and guidance documents related to stakeholder involvement, it is important that it adhere to its own guidance, particularly in the con- text of cumulative risk assessment, in which communities often have not been adequately involved. Recommendation: EPA should establish a formal process for stakeholder involvement in the framework for risk-based decision-making with time limits to ensure that deci- sion-making schedules are met and with incentives to allow for balanced participation of stakeholders, including impacted communities and less advantaged stakeholders. Capacity-building Improving risk-assessment practice and implementing the framework for risk-based deci- sion-making will require a long-term plan and commitment to build the requisite capacity of information, skills, training, and other resources necessary to improve public-health and environmental decision-making. The committee’s recommendations call for considerable modification of EPA risk-assessment efforts (for example, implementation of the risk-based decision-making framework, emphasis on problem formulation and scoping as a discrete stage in risk assessment, and greater stakeholder participation) and of technical aspects of risk assessment (for example, unification of cancer and noncancer dose-response assessments, attention to quantitative uncertainty analysis, and development of methods for cumulative risk assessment). The recommendations are tantamount to “change-the-culture” transforma- tions in risk assessment and decision-making in the agency. EPA’s current institutional structure and resources may pose a challenge to implementa- tion of the recommendations, and moving forward with them will require a commitment to leadership, cross-program coordination and communication, and training to ensure the requisite expertise. That will be possible only if leaders are determined to reverse the downward trend in budgeting, staffing, and training and to making high-quality, risk-based decision-making an agencywide goal. Recommendation: EPA should initiate a senior-level strategic re-examination of its risk- related structures and processes to ensure that it has the institutional capacity to imple- ment the committee’s recommendations for improving the conduct and utility of risk assessment for meeting the 21st century environmental challenges. EPA should develop a capacity building plan that includes budget estimates required for implementing the committee’s recommendations, including transitioning to and effectively implementing the framework for risk-based decision-making.

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21 TOWARD IMPROVED RISK-BASED DECISION-MAKING REFERENCES Callahan, M.A. 2007. Improving Risk Assessment: A Regional Perspective. Presentation at the Third Meeting of Improving Risk Analysis Approaches Used by EPA, February 26, 2007, Washington, DC. Callahan, M.A., and K. Sexton. 2007. If cumulative risk assessment is the answer, what is the question? Environ. Health Perspect. 115(5):799-806. EPA (U.S. Environmental Protection Agency). 1992. Guidelines for Exposure Assessment. EPA600Z-92/001. Risk Assessment Forum, U.S. Environmental Protection Agency, Washington, DC [online]. Available: http://cfpub. epa.gov/ncea/raf/recordisplay.cfm?deid=15263 [accessed Jan. 14, 2008]. EPA (U.S. Environmental Protection Agency). 1998. Guidelines for Ecological Risk Assessment. EPA/630/R- 95/002F. Risk Assessment Forum, U.S. Environmental Protection Agency, Washington, DC. April 1998 [online]. Available: http://oaspub.epa.gov/eims/eimscomm.getfile?p_download_id=36512 [accessed Feb. 9, 2007]. EPA (U.S. Environmental Protection Agency). 2001. Trichloroethylene Health Risk Assessment: Synthesis and Characterization. External Review Draft. EPA/600/P-01/002A. Office of Research and Development, Wash- ington, DC. August 2001 [online]. Available: http://rais.ornl.gov/tox/TCEAUG2001.PDF [accessed Aug. 2, 2008]. EPA (U.S. Environmental Protection Agency). 2002. A Review of the Reference Dose and Reference Concentration Processes. EPA/630/P-02/002F. Risk Assessment Forum, U.S. Environmental Protection Agency, Washington, DC. December 2002 [online]. Available: http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=55365 [accessed Jan. 4, 2008]. EPA (U.S. Environmental Protection Agency). 2003. Framework for Cumulative Risk Assessment. EPA/600/ P-02/001F. National Center for Environmental Assessment, Risk Assessment Forum, U.S. Environmen- tal Protection Agency, Washington, DC [online]. Available: http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm? deid=54944 [accessed Jan. 4, 2008]. EPA (U.S. Environmental Protection Agency). 2004. Risk Assessment Principles and Practices: Staff Paper. EPA/100/ B-04/001. Office of the Science Advisor, U.S. Environmental Protection Agency, Washington, DC. March 2004 [online]. Available: http://www.epa.gov/osa/pdfs/ratf-final.pdf [accessed Jan. 9, 2008]. EPA (U.S. Environmental Protection Agency). 2005a. Guidelines for Carcinogen Risk Assessment. EPA/630/ P-03/001F. Risk Assessment Forum, U.S. Environmental Protection Agency, Washington, DC. March 2005 [online]. Available: http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=116283 [accessed Feb. 7, 2007]. EPA (U.S. Environmental Protection Agency). 2005b. Supplemental Guidance for Assessing Susceptibility for Early-Life Exposures to Carcinogens. EPA/630/R-03/003F. Risk Assessment Forum, U.S. Environmental Pro- tection Agency, Washington, DC. March 2005 [online]. Available: http://cfpub.epa.gov/ncea/cfm/recordisplay. cfm?deid=160003 [accessed Jan. 4, 2008]. Kyle, A. 2007. Community Needs for Assessment of Environmental Problems. Presentation at the Fourth Meeting of Improving Risk Analysis Approaches Used by EPA, April 17, 2007, Washington, DC. NRC (National Research Council). 1983. Risk Assessment in the Federal Government: Managing the Process. Washington, DC: National Academy Press. NRC (National Research Council). 1996. Understanding Risk: Informing Decisions in a Democratic Society. Wash- ington, DC: National Academy Press. NRC (National Research Council). 2006. Assessing the Human Risks of Trichloroethylene. Washington, DC: The National Academies Press. NRC (National Research Council). 2008. Phthalates and Cumulative Risk Assessment: The Tasks Ahead. Wash- ington, DC: The National Academies Press. PCCRARM (Presidential/Congressional Commission on Risk Assessment and Risk Management). 1997. Frame- work for Environmental Health Risk Management - Final Report, Vol. 1. [online]. Available: http://www. riskworld.com/nreports/1997/risk-rpt/pdf/EPAJAN.PDF [accessed Jan. 4, 2008]. Renner, R. 2007. Budget cut increasingly damaging to EPA. Environ. Sci. Technol. News, May 9, 2007 [online]. Available: http://pubs.acs.org/subscribe/journals/esthag-w/2007/may/policy/rr_EPA.html [accessed Aug. 12, 2008].

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