Review of pesticide carcinogenesis data and regulatory approaches.

Carcinogenicity data are presented for compounds used as pesticides which have been evaluated in the IARC Monograph series. These pesticides have been both poorly and scantily tested for carcinogenicity. Additional tests have been carried out under the NCI Carcinogenesis Program, and detailed results of the bioassays are published in the NCI Carcinogenesis Technical Report Series. A prpcedure was developed whereby 'preliminary reports' could be made in the Federal Register. In the second part of the paper, regulatory approaches to pesticides are described. International activities are outlined; and examples are given of factors, such as public concern, scientific work and governmental response, which are highlights in the development of approaches to such regulations. The problem of risk assessment has been approached from many sides but remains largely unsolved. Besides risks and benefits, an essential component in evaluation is the analysis of technological alternatives. Two other factors are public documentation of the process of evaluation and registration of environmental carcinogens and their uses. Reduction of exposure to environmental carcinogens to a 'minimum feasible level' depends on social, economic and temporal factors and implies the acceptance of a finite level of risk.