Carcinogenicity testing of chemicals with particular reference to organochlorine pesticides.

The organochlorine chemicals comprise a large number of pesticides that are used widely throughout the world. The organochlorine pesticides given in the diet to mice are carcinogenic for the liver. They induce not only carcinomas of the liver, particularly at the higher doses, but also carcinomas and sarcomas in other organs in rats. They cause acute and chronic liver and kidney injury, which interferes with the development of carcinomas and sarcomas in rats. The testing of chemicals for carcinogenicity, with particular reference to organochlorine pesticides, includes discussions on the following topics: classification of hepatic lesions in mice and rats, toxicity versus carcinogenicity in the testing of chemicals, a comparison of carcinomas and cirrhosis of the liver in experimental animals and humans, and the significance of laboratory carcinogenicity findings to human health.