Comparing Environmental Risks: Can Scientists Satisfy Politicians' Demands? William S. Pease, Center for Occupational and Environmental Health, School of Public Health, University of California, Berkeley, California 94720-7360
Current federal legislative proposals to reform environmental regulation all include mandates for agencies to establish priorities based on sound science and comparative risk assessment. Existing state and federal efforts to compare risks and prioritize environmental problems for regulatory action represent valuable experiments in the use of different methods and processes for ranking risks. Results of an evaluation of a sample of these projects, including the recent California Comparative Risk Project, will be presented. The analysis identifies the strengths and weaknesses of methods used to conduct three critical components of comparative risk assessment: defining the environmental problem areas to be evaluated, extrapolating from available data to reach summary judgments of the environmental health impact of problem areas, and integrating the results of rankings across multiple risk attributes. Use of ranking results in the policy process will also be examined. To date, such projects have not fulfilled the expectations of politicians that objective, fact-based analysis can replace current politicized approaches to setting priorities. Delineating the limits of science-based approaches to ranking risks and describing the process-based approaches some projects have used to overcome these limits can help reframe the debate about how to set environmental priorities.