Guidance and Workshops on Aggregate and Cumulative Assessments

1. Planning and scoping for cumulative risk assessment What: description of concepts for up-front thinking to lay out process Why:guide the first step, emphasizing broad scope & integrated dialogue Who: Office of Science Policy When:1997 (guidance) Workshops on Chemical Mixtures Health Risk Assessment What: teaches risk assessment methods for evaluating multiple chemicals Why:technical transfer to the risk assessment community Who: National Center for Environmental Assessment When:2000-2005 (workshops at the Society for Risk Analysis National Meeting, the Toxicology and Risk Assessment Annual Conference, Regional and State EPA groups). Agency Guidelines and Guidance Published guidance on approaches for cumulative risk assessment include the 1986 mixture risk guidelines, the 1989 toxicity equivalence factor approach for dioxins, the 1997 guidance on planning and scoping for cumulative risk, the 2000 supplementary guidance for mixture risk, and the 2003 framework for conducting cumulative risk assessment. Future publications include a report on approaches for conducting cumulative risk assessment at contaminated sites (2005) and cumulative risk assessment guidelines (2012). Workshops and Training Workshops held by the Office of Science Policy, the Risk Assessment Forum, the National Center for Environmental Research and the National Center for Environmental Assessment range from training sessions on assessment methods in published EPA guidance to discussions of case studies from Regional and Program Offices. Most of these are open to the public. The interaction between the scientists, risk managers, academics and stakeholders addresses technical and implementation issues, such as relevant mathematical models, quantitative uncertainties, jargon differences, software, measurements, and critical research gaps. Recent workshops include the application of dioxin toxicity equivalence factors to fish and wildlife (1998), mixture risk assessment training at the Society for Risk Analysis annual meetings (1999 - 2004), and the joint ORD-Regional workshop on cumulative risk assessment (2002) at which several Regional and Program Office case studies of cumulative risk assessments were described. Planning and scoping lessons learned What: summary of experience from studies since the 1997 guidance Why:encourage formal planning & scoping of environmental assessments Who: Office of Science Policy When:2002 (report with case studies) Workshop on cumulative risk assessment What: user-based evaluation of current programs, approaches, and needs Why:focus and prioritize Agency research, leverage interagency efforts Who: Office of Science Policy, with Regional Offices When:2002 (workshop summary) Framework for cumulative risk assessment What: description of umbrella issues, concepts, and general approaches Why:guide overall integrated organization for many types of assessments Who: Risk Assessment Forum When:2003 (framework report) Approaches for cumulative health risk assessment What: ways to assess combined health risks at contaminated sites Why:translate basic concepts to suggestions for practical implementation Who: National Center for Environmental Assessment When:2005 (planned final report) Case studies for cumulative risk assessment What:summary of examples, including community-based pilot studies Why:provide insights to help others conduct cumulative risk assessments Who: Risk Assessment Forum When:2005-2006 (effort underway) Guidance and Workshops on Aggregate and Cumulative Assessments Rick Hertzberg1, Ed Bender2, David Klauder2, Linda Teuschler1, Glenn Rice1, and Bill Wood1, Chris Saint3 U.S. Environmental Protection Agency, Office of Research and Development, 1NCEA, 2OSP, 3NCER Impact and Outcomes Science Question How can theoretical and laboratory research be developed into feasible tools and approaches for conducting and communicating aggregate and cumulative risk assessment? How can assessment models and procedures be harmonized across aggregate and cumulative assessments? How can we quantify environmental and physiological interactions in aggregate exposures to a single chemical so that those interactions can be incorporated into risk assessment guidance? How important qualitatively and quantitatively are interactions- in transport, environmental transformation, and toxicity of multiple chemicals, especially at environmental levels? Can tiered approaches be developed to assist risk assessors in addressing interactions only when needed? Development and communication of practical methods for conducting aggregate and cumulative risk assessment, in the form of risk assessment guidance and training, not only improves the dialogue between researchers, decision makers and stakeholders, but also leads to more accurate and complete risk estimation. ORD’s supplementary mixture risk guidance (EPA 2000) and related training workshops led to ORD participation in the Office of Pesticide Programs’ development of cumulative risk guidance, and inclusion of ORD’s relative potency factor approach in that guidance. Previous criticism that EPA’s mixture risk assessments ignored synergism and antagonism is now solved by ORD’s interaction-based Hazard Index (EPA 2000). Chemical mixtures: guidance for assessing health risks What: how to evaluate mixtures data, approaches for whole mixtures, index chemicals methods for groups, interactions data usage Why:update 1986 guidelines for multiple chemicals to enhance methods Who: National Center for Environmental Assessment When:2000 (guidance) Future Directions Research Goals Aggregate and cumulative risk assessments, both fairly new to EPA, will push toward a paradigm shift in Agency risk management. Shifting from traditional source based risk assessments to population based cumulative risk assessments (EPA 2003) addresses community concerns, including environmental justice issues, of combined impacts on susceptible communities from multiple exposures. Risk estimates made for whole communities or for complex sites have the potential for tremendous health and economic impacts; thus research to improve risk assessment methods, harmonization through Agency-wide guidance, and training on application of such methods is critical. The complexity of aggregate and cumulative risk assessments is best approached by an interdisciplinary team that ranges from bench scientists, epidemiologists and mathematicians to frontline enforcers of regulations. ORD has stimulated that activity by two main vehicles: agency risk assessment guidance and open workshops. Agency guidance from ORD is usually either focused guidance from individual labs or centers, or guidelines from the Risk Assessment Forum that form Agency science policy. Risk assessment guidance often addresses complex issues using methods based mainly on structured scientific judgment, including science policy decisions for default approaches and values. By including Program and Regional Offices in the authorship and review, ORD guidance usually has broad concurrence and covers wide ranges of application. Workshop on Application of dioxin TEF’s to fish and wildlife What: evaluate uncertainties in TEF development and their impact in ecological risk assessments Why:animals are exposed to complex mixtures of dioxins and furans Who: EPA Regional Offices and ORD, and Dept. of the Interior When:1998 (workshop report 2001) References Risk Assessment Forum http://cfpub.epa.gov/ncea/raf/index.cfm Office of Science Policy http://www.epa.gov/osp/regions/cumrisk_rep.pdf Workshop on STAR Grants- Session on mixtures risk assessment What:public presentations on Science To Achieve Results Program Why:foster exchange between EPA scientists and STAR grant recipients Who: National Center for Environmental Research and Region III When:October 28-29, 2004, Philadelphia Guidelines for cumulative risk assessment What: approaches for assessing multiple route exposures to chemical mixtures and other non-chemical stressors from multiple sources over time; population-based assessments, including vulnerable subpopulations Why:address concerns about combined risks in urban communities Who: Risk Assessment Forum Technical Panel When:2012 (guidelines)