Chemical Risk Assessment Selected Federal Agencies Procedures Assumptions And Policies Report To Congressional Requesters PDF Download

As used in public health and environmental regulation, risk assessment is the systematic, scientific description of potential adverse effects of exposures to hazardous substances or situations. It is a complex but valuable set of tools for federal regulatory agencies, helping them to identify issues of potential concern, select regulatory options, and estimate the range of a forthcoming regulations benefits. For example, the Environmental Protection Agency (EPA) used risk assessment information in a 1998 final rule to conclude that disinfection byproducts (e.g., chloroform) in drinking water could cause as many as 9,300 bladder cancer cases a year, and that a 24-percent reduction in those byproducts could result in monetized health benefits of about $4 billion. However, risk assessments are also sometimes controversial, as evidenced by the fact that the disinfection byproduct rule was successfully challenged in court over whether the agency used the best scientific evidence available in support of certain assumptions. 2 Given the significant yet controversial nature of risk assessments, it is important that policymakers understand how risk assessments are conducted, the extent to which risk estimates produced by different agencies and programs are comparable, and the reasons for differences in agencies risk assessment approaches and results.