ABSTRACT
Regulation of toxic substances is an extremely complex, uncertain, and controversial enterprise. The regulatory process is customarily divided into two discrete functions: risk assessment and risk management. Risk assessment ostensibly is a scientific activity that develops estimates of human health hazards or environmental hazards at varying pollutant exposure levels, whereas risk management is a political activity that balances competing interests and values to determine whether identified toxic risks should be considered unacceptable or tolerable (U.S. NRC 1983). Risk management is the process of weighing policy alternatives and selecting the most appropriate regulatory action, integrating the results of risk assessment with social, economic, and political concerns. This sharp distinction between the scientific and social policy dimensions of toxics regulation is embodied in the U.S. Environmental Protection Agency’s (EPA) guidelines (1986a), which state that risk assessments must “use the most scientifically appropriate interpretation” and should “be carried out independently from considerations of the consequences of regulatory action.” The U.S. EPA and other federal agencies stress the need for scientifically credible risk assessments and presume that their analyses should be grounded exclusively on the best available scientific theories and data, even if the resulting predictions do not achieve the degree of reliability ordinarily required for valid scientific conclusions.
We challenge this view that only scientific perspectives should dominate the risk assessment process. Risk assessment is too important and too uncertain to be 304 left exclusively to the risk assessors. Instead, social policy considerations must play as prominent a role in the choice of risk estimates as in the ultimate determination of which predicted risks should be deemed unacceptable .
