ABSTRACT
Since some risks can be at least approximately quantified, it is obvious that when such risks are being considered quantitative assessments of the relative risks among different scenarios provide useful input for priority setting. EPA’s present problem with choosing from among the many different potential risks to human health and the environment stems from the fact that most of those within its jurisdiction are small and roughly equal. The uncertainty in estimating the risks to real or hypothetical individuals is substantial, large enough to obscure differences among them. The uncertainty in the differences among risks inferred from toxicologic data can be reduced by a population-based method: estimating the number of individuals likely to be exposed above some response level such as an ED05. However, risk comparisons are not an adequate sole criterion for priority setting; values must also be considered, and brought in through the normal political process. Properly applied, risk assessment can serve to bring into the process the relevant scientific information, thus allowing the political decisions to be made in greater clarity.
