1. SCIENCE AND DECISIONS: ADVANCING RISK ASSESSMENT
National Research Council
Committee on Improving Risk Analysis Approaches Used by EPA
Board on Environmental Studies and Toxicology
Society for Risk Analysis - New England Chapter
January 29, 2009
Report came as a request from Clayton Teague, director of the NNI
Done with support from the NMAB
The report has gone through peer review. The committee has not had a final review of the draft report.

2. STUDY MOTIVATION
Risk assessment is at a crossroads, and its credibility is being challenged.
Science is increasingly complex.
Risk assessment is being extended to address broader environmental questions, such as life-cycle analysis and issues of costs, benefits, and risk-risk tradeoffs.
Stakeholders are often disengaged from the risk-assessment process at a time when risk assessment is increasingly intertwined with societal concerns.
Disconnects between the available scientific data and the information needs of decision-makers hinder the use of risk assessment as a decision-making tool.

3. COMMITTEE’S CHARGE
Develop scientific and technical recommendations for improving risk analysis approaches used by EPA, including practical improvements that EPA could make in the near term (2-5 years) and in the longer term (10-20 years).
Focus primarily on human health risk assessment but also consider broad implications of findings and recommendations for ecologic risk analysis.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

4. COMMITTEE
Thomas Burke (Chair), Johns Hopkins Bloomberg School of Public Health
A. John Bailer, Miami University
John M. Balbus, Environmental Defense
Joshua T. Cohen, Tufts Medical Center
Adam M. Finkel, University of Medicine and Dentistry of New Jersey
Gary Ginsberg, Connecticut Department of Public Health
Bruce K. Hope, Oregon Department of Environmental Health
Jonathan I. Levy, Harvard School of Public Health
Thomas E. McKone, University of California
Gregory M. Paoli, Risk Sciences International
Charles Poole, University of North Carolina School of Public Health
Joseph V. Rodricks, ENVIRON International Corporation
Bailus Walker Jr., Howard University Medical Center
Terry F. Yosie, World Environment Center
Lauren Zeise, California Environmental Protection Agency

5. EVALUATION The committee focused on two broad elements:
Improving technical analysis
Entails the development and use of scientific knowledge and information to improve characterizations of risk.
Improving utility
Entails making risk assessment more relevant and useful for risk-management decisions.
Study requested by NNI in 2007, document released in February 2008
Part of charge was to conduct a workshop

6. KEY MESSAGES
Enhanced framework
Formative focus
Four steps still core
Matching analysis to decisions
Clearer estimates of population risk
Advancing cumulative assessments
People and capacity building

7. CONCLUSIONS AND RECOMMENDATIONS
Design of risk assessment
Uncertainty and variability
Selection and use of defaults
Unified approach to dose-response assessment
Cumulative risk assessment
Improving the utility of risk assessment
Stakeholder involvement
Capacity-building
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

8. DESIGN OF RISK ASSESSMENT
Design The process of planning a risk assessment and ensuring that its level and complexity are consistent with the needs to inform decision-making.
Recommendations
Increased attention to the design of risk assessment in its formative stages.
Planning and scoping and problem formulation (as in EPA ecological and cumulative risk guidance) should be formalized and implemented.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

9. VALUE OF INFORMATION
Value of information (VOI) cannot be ascertained without comprehensive uncertainty characterization, well-framed decision context
Formal quantitative VOI analysis may not be feasible in many settings, but essential reasoning behind VOI can be more widely utilized
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

10. UNCERTAINTY
There have been substantial differences among EPA’s approaches to and guidance for addressing uncertainty in exposure and dose-response assessment.
The level of detail for characterizing uncertainty is appropriate only to the extent that it is needed to inform specific risk-management decisions appropriately.
Inconsistency in the treatment of uncertainty among components of a risk assessment can make the communication of uncertainty difficult and sometimes misleading.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

11. VARIABILITY
Variability in human susceptibility has not received sufficient or consistent attention in many EPA health risk assessments (exceptions include lead and ozone)
Committee encourages EPA to move toward the long-term goal of quantifying population variability more explicitly in exposure assessment and dose-response relationships.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

12. UNCERTAINTY AND VARIABILITY
Recommendations
EPA should encourage risk assessments to characterize and communicate uncertainty and variability in all key computational steps.
Uncertainty and variability analysis should be planned and managed to reflect the needs for comparative evaluation of the risk management options.
In the short term, EPA should adopt a “tiered” approach for selecting the level of detail in uncertainty and variability assessments
This should be made explicit in the planning stage.
EPA should develop guidance on the appropriate level of detail needed in uncertainty and variability analyses
Provide clear definitions and methods for identifying and addressing different sources of uncertainty and variability.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

13. SELECTION AND USE OF DEFAULTS
Uncertainty is inherent in all stages of risk assessment
EPA typically relies on assumptions when chemical-specific data are not available.
Much scientific controversy and delay in completion of some risk assessments
In part (clearly not in total) related to the long debates on adequacy of the data to support use of a default or an alternative approach.
1983 Red Book recommended guidelines to select defaults
To ensure consistency and to avoid manipulations in the risk-assessment process.
Committee acknowledges EPA’s efforts to examine scientific data related to defaults, but changes are needed to improve the agency’s use of them.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

14. SELECTION AND USE OF DEFAULTS
Established defaults need to be maintained for risk assessment steps that require inferences
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 instead of a default.
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.
There are a number of defaults (missing or implicit defaults) that are engrained in EPA risk-assessment practice but are absent from its risk-assessment guidelines.
EPA does not quantify uncertainty when default assumptions are used.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

15. SELECTION AND USE OF DEFAULTS
Recommendations
EPA should
continue and expand use of the best, most current science to support and revise default assumptions.
develop clear, general standards for the level of evidence needed to justify the use of alternative assumptions in place of defaults.
work toward the development of explicitly stated defaults to take the place of implicit defaults.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

16. SELECTION AND USE OF DEFAULTS
Evidentiary Standard for Replacing Default
“The committee recommends that EPA adopt an alternative assumption in place of a default when it determines that the alternative is ‘clearly superior’, that its plausibility clearly exceeds the plausibility of the default.”
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

17. SELECTION AND USE OF DEFAULTS Showing Uncertainty When Using Defaults
To the extent feasible, EPA should move beyond qualitative description of uncertainty when default assumptions are used
Long term – improved probabilistic description of uncertainty commensurate with risk management needs
Short term, EPA should develop criteria for listing alternative values.
Goal – Provide sensitivity analysis to illustrate impact of alternative assumptions and hence characterize robustness of risk estimates
Limit attention to assumptions with plausibility comparable to the default
Goal is not an exhaustive presentation of plausible estimates
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

18. UNIFICATION APPROACH TO DOSE-RESPONSE ASSESSMENT
Historically, dose-response assessments at EPA conducted differently for cancer and noncancer effects
Methods have been criticized for not providing the most useful results.
A consistent approach to risk assessment for cancer and noncancer effects is scientifically feasible and needs to be implemented.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

19. Current Approach to Dose-Response Assessment

20. Current EPA Dose-Response Approach
EPA has taken important steps to harmonize cancer and noncancer approaches, but with many scientific and operational limitations:
Noncancer effects do not necessarily have threshold or low-dose nonlinearity
The mode of action of carcinogens varies.
Background exposures and underlying disease processes contribute to population background risk
can lead to linearity at the population doses of concern.
RfDs and RfCs do not quantify risk for different magnitudes of exposure but rather provide a bright line
Their use in risk-management decision-making is limited.
Cancer risk assessments usually do not account for human differences in cancer susceptibility (other than possible differences in early-life).
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

21. Dose-response relationship is dependent on heterogeneity in: ■ Background exposure (endogenous and xenobiotic) ■ Biological susceptibility

22. UNIFICATION OF DOSE-RESPONSE ASSESSMENT Recommendations
A consistent, unified approach for dose-response modeling that includes formal, systematic assessment of
background disease processes and exposures
possible vulnerable populations
modes of action that may affect a chemical’s dose-response in humans.
Redefine the RfD or RfC as a risk-specific dose
provides information on the percentage of the population expected above or below a defined acceptable risk (with specific degree of confidence).
Formal introduction of variability into cancer dose-response modeling
Will require implementation and development
As new chemicals are assessed or old chemicals are reassessed
Of test cases to demonstrate proof of concept.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

23. Unification Approach to Dose-Response Assessment

24. Diagnostic Questions to Aid Dose-Response Assessment
What is known or suspected to be the chemical’s MOA?
What underlying degenerative or disease processes might the toxicant affect?
What are the background incidences and population distributions of these processes?
Are there identified sensitive populations?
What environmental contaminants in air, drinking water, food or in consumer products (e.g., in cosmetics) or endogenous chemicals (e.g., natural hormones) are similar to the chemical?
Could they potentially operate by MOAs similar to that of the chemical in question?
What chemicals might operate by a different MOA but have the potential to affect the same toxic process as the chemical under study?
Can subgroups with particularly high exposures be identified?
…more
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

25. Conceptual Dose-Response Model – Based on MOA, Background Exposure and Disease Processes

26. CUMULATIVE RISK ASSESSMENT
EPA is increasingly asked to address broad public-health and environmental-health issues that stakeholder groups often consider inadequately captured by current risk assessments
multiple exposures
complex mixtures
vulnerability of exposed populations
There is a need for cumulative risk assessments as defined by EPA that include
combined risks posed by exposure to multiple agents or stressors
aggregate exposure to a given agent or stressor
all routes, pathways, and sources of exposure
Chemical, biologic, radiologic, physical, and psychologic stressors are considered.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

27. CUMULATIVE RISK ASSESSMENT
Committee applauds the agency’s move toward the broader definition, 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 supported by agency guidelines.
Little consideration of nonchemical stressors, vulnerability, and background risk factors.
Because of the complexity of considering so many factors simultaneously, there is a need for:
Simplified risk assessment tools
Orientation around pertinent risk management options to limit the number of stressors under formal consideration
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

28. Identify the receptors and end points affected by these stressors.
Step 1:
Develop a conceptual model for the stressors of primary interest for the analysis (stressors that would be significantly influenced by any of the risk-management options under study).
MOA assessment, assessment of background exposures to chemical and nonchemical stressors that may affect the same health outcome, vulnerability assessment that takes into account underlying disease processes in the population
Identify the receptors and end points affected by these stressors.
Review the conceptual model and stressors, receptors, and end points of interest with stakeholders in initial planning and scoping.
Step 2:
Use epidemiologic and toxicologic evidence and screening-level benefit calculations to provide an initial evaluation of which stressors should be included in the cumulative risk assessment. Gather stakeholder feedback and review and re-evaluate planning and scoping for the analysis.
Focus the assessment only on stressors that contribute to end points of interest for risk-management options and are either differentially affected by different control strategies or influence the benefits of stressors that are differentially affected.
Step 3:
Evaluate benefits of different risk-management options with appropriate characterization of uncertainty, including quantification of the effects of individual stressors and bounding calculations of any possible interaction effects.
Step 4:
If Step 3 is sufficient to discriminate among risk-management options given other economic, social, and political factors, conclude the analysis; otherwise, sequentially refine the analysis as needed, taking into account potential interactions.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

29. CUMULATIVE RISK ASSESSMENT
Recommendations
EPA should
Draw on other approaches to incorporate interactions between chemical and non-chemical stressors in assessments, including those from ecologic risk assessment and social epidemiology
Develop guidelines and methods for simpler analytical tools
to support cumulative risk assessment
to provide for greater involvement of stakeholders.
In short-term, develop databases and default approaches to allow for incorporation of key non-chemical stressors in the absence of population-specific data, considering
exposure patterns
contributions to relevant background processes
interactions with chemical stressors.
In long-term, invest in research programs related to interactions between chemical and non-chemical stressors, including epidemiologic investigations and physiologically-based pharmacokinetic modeling.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

30. IMPROVING THE UTILITY OF RISK ASSESSMENT
Committee proposes a framework for risk-based decision-making.
At core is risk assessment paradigm from Red Book
Differs from Red Book primarily in its initial and final steps
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?
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

31. IMPROVING THE UTILITY OF RISK ASSESSMENT
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 needed to evaluate the relative merits of the options being considered.
Risk management
choosing among the options after the appropriate assessments have been undertaken and evaluated.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

32. This was informed by public sessions, including from representatives of NNI member agencies and workshop where representatives from insurance industry, consumer groups, industry were asked to comment on whether the strategy addresses their needs and what they saw as the strengths and limitations of the strategy.
NNI document does not provide an evaluation of the state of the science in each of the five research categories; rather the research is evaluated against research projects that were funded in FY NNI document uses the FY2006 data to assess the extent which federally funded EHS research related to nanomaterials is supporting selected research priorities and to conduct its gap analysis of the NNI research portfolio.
There is no clear statement of how the FY2006 research projects would address the identified research needs and inform an understanding of potential human health and environmental risks posed by engineered nanoscale materials.

33. IMPROVING THE UTILITY OF RISK ASSESSMENT Phase I: Problem Formulation and Scoping
What is the problem to be investigated, and what is its source?
What are the possible opportunities for managing risks associated with the problem? Has a full array of possible options been considered, including legislative requirements?
What types of risk assessments and other technical and cost assessments are necessary to evaluate existing conditions and how the various risk-management options alter the conditions?
What impacts other than health and ecosystem threats will be considered?
How can the assessments be used to support decisions?
What is the required timeframe for completion of assessments?
What resources are needed to undertake the assessments?
This was informed by public sessions, including from representatives of NNI member agencies and workshop where representatives from insurance industry, consumer groups, industry were asked to comment on whether the strategy addresses their needs and what they saw as the strengths and limitations of the strategy.
NNI document does not provide an evaluation of the state of the science in each of the five research categories; rather the research is evaluated against research projects that were funded in FY NNI document uses the FY2006 data to assess the extent which federally funded EHS research related to nanomaterials is supporting selected research priorities and to conduct its gap analysis of the NNI research portfolio.
There is no clear statement of how the FY2006 research projects would address the identified research needs and inform an understanding of potential human health and environmental risks posed by engineered nanoscale materials.

34. Planning and Conduct of Risk Assessment
Phase II
Planning and Conduct 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?
Stage 2: Risk Assessment
Stage 3: Confirmation of the Utility
■ Does the assessment have the attributes called for in planning?
■ Does the assessment provide sufficient information to discriminate among risk-management options?
■ Has the assessment been satisfactorily peer reviewed?
This was informed by public sessions, including from representatives of NNI member agencies and workshop where representatives from insurance industry, consumer groups, industry were asked to comment on whether the strategy addresses their needs and what they saw as the strengths and limitations of the strategy.
NNI document does not provide an evaluation of the state of the science in each of the five research categories; rather the research is evaluated against research projects that were funded in FY NNI document uses the FY2006 data to assess the extent which federally funded EHS research related to nanomaterials is supporting selected research priorities and to conduct its gap analysis of the NNI research portfolio.
There is no clear statement of how the FY2006 research projects would address the identified research needs and inform an understanding of potential human health and environmental risks posed by engineered nanoscale materials.

35. Phase III Risk Management
■ What are the relevant health or environmental benefits of the proposed risk-management options?
■ How are other decision-making factors (technologies, costs) affected by the proposed options?
■ What is the decision, and its justification, in light of benefits, costs, and uncertainties in each?
■ How should the decision be communicated?
■ Is it necessary to evaluate the effectiveness of the decision? If so, how should this be done?
This was informed by public sessions, including from representatives of NNI member agencies and workshop where representatives from insurance industry, consumer groups, industry were asked to comment on whether the strategy addresses their needs and what they saw as the strengths and limitations of the strategy.
NNI document does not provide an evaluation of the state of the science in each of the five research categories; rather the research is evaluated against research projects that were funded in FY NNI document uses the FY2006 data to assess the extent which federally funded EHS research related to nanomaterials is supporting selected research priorities and to conduct its gap analysis of the NNI research portfolio.
There is no clear statement of how the FY2006 research projects would address the identified research needs and inform an understanding of potential human health and environmental risks posed by engineered nanoscale materials.

36. IMPROVING THE UTILITY OF RISK ASSESSMENT
The framework…
Systematically identifies problems and options that risk assessors should evaluate at the earliest stages of decision-making.
Expands the array of impacts assessed beyond individual effects (e.g., respiratory effects) to include broader questions (e.g., health status and ecosystem protection).
Provides a formal process for stakeholder involvement.
Increases understanding of the strengths and limitations of risk assessment by decision-makers at all levels, e.g., by making uncertainties and choices more transparent.
Maintains the conceptual distinction between risk assessment and risk management articulated in the Red Book.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

37. IMPROVING THE UTILITY OF RISK ASSESSMENT
Recommendation
EPA adopt a framework for risk-based decision-making 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.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

38. STAKEHOLDER INVOLVEMENT
Many stakeholders believe that the current process for developing and applying risk assessments lacks credibility and transparency.
Greater stakeholder involvement is necessary
to ensure that the process is transparent and
to ensure risk-based decision-making proceeds effectively, efficiently, and credibly.
Stakeholder involvement needs to be an integral part of the risk-based decision-making framework.
It is important that EPA adhere to its own guidance on stakeholder involvement
particularly in the context of cumulative risk assessment, in which communities often have not been adequately involved.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

39. STAKEHOLDER INVOLVEMENT
Recommendation
EPA should establish a formal process for stakeholder involvement in the framework for risk-based decision-making with:
time limits to ensure that decision-making schedules are met
incentives to allow for balanced participation of stakeholders including impacted communities and less advantaged stakeholders.
18 participating government agencies in NEHI
OSTP, OMB, CPSC< USDA CSREES, DOD, DEO, DOS, DOT, EPA, FDA, ITC, NASA, NIOSH, NIST, NIH, OSHA, USGS

40. CONCLUDING REMARKS
Risk assessment remains essential to the agency’s mission to ensure protection of public health and the environment.
The committee hopes that the recommendations and the proposed framework for risk-based decision-making will provide a template for the future of risk assessment in EPA and strengthen the scientific basis, credibility, and effectiveness of future risk-management decisions.
What are the elements of an effective nano-risk research strategy?
Committee considered what defines a strategy in general, and then more specifically a risk-research strategy.
Strategy generally defines a set of goals, often in the context of an overarching vision, a plan of action for achieving the goals; and milestones to indicate when the goals are expected to be achieved.
Risk-research strategy addresses challenges of broad public health or environmental significance
Nano-risk research strategy needs to be proactive, identifying possible risks and mitigating ones that need to be addressed before the technology is widespread commercial presence.
Nano-risk strategy must address those materials that are entering commerce and those under development.
A nanotechnology-related research strategy must rely on both targeted research, which addresses questions critical for ensuring the safety of nanomaterials and products that contain them, and exploratory research, which generates new knowledge that will inform future goals and research directions.
Committee defined nine elements that are integral to any effective risk-research strategy and these informed the committee’s evaluation of the federal strategy.