Environmental chemical carcinogenesis

The methodology of revealing and studying chemical carcinogens in the environment is based on epidemiology, animal testing, and short-term laboratory studies. The techniques and limitations of these respective investigations are described. From evidence of carcinogenicity, extrapolation must be made to assess whether a particular substance is a cause of cancer in humans. This inference depends upon the type of evidence for carcinogenicity. In particular, parameters limiting extrapolation of all laboratory assays include species' specificity and dose response. Control of the environmental distribution of punative carcinogens poses difficulty, both in the selection of substances, and in legislative design. Certain personal habits still constitute the major established carcinogenic hazards for the community-at-large.