DDT: Epidemiological evidence.

The use of DDT as a pesticide, until its banning in many countries, is reviewed briefly. The tissue levels of DDT can be regarded as an index of past exposures, and findings in several countries are described. It is emphasized that insufficient case-control studies are available for evaluation and that assessment of the potential carcinogenic effects of DDT in humans is largely dependent on inferences from descriptive epidemiology. DDT is a non-genotoxic carcinogen in animals and a mild hepatoxic agent. The liver is a probable target organ in man. No correlation at the population level can be demonstrated between exposures to DDT and the incidence of cancer at any site. It is concluded that DDT has had no significant impact on human cancer patterns and is unlikely to be an important carcinogen for man at previous exposure levels, within the statistical limitations of the data.