The place of epidemiology in environmental decisions: needed support for the development of risk assessment policy.

Some of the most challenging problems in the use of epidemiology for regulatory policy concern summarizing epidemiological and other kinds of information to create a weight of evidence. Another frequent issue is whether to embark on epidemiological study. There are also concerns that negative results never see the light of day. These and other meta-issues are worthy of funded evaluation by expert work groups.