DETECTION OF CARCINOGENS AS MUTAGENS IN SALMONELLA-MICROSOME TEST .2. ASSAY OF 300 CHEMICALS - DISCUSSION

The test uses bacteria as sensitive indicators of DNA damage and mammalian liver extracts for metabolic conversion of carcinogens to their active mutagenic forms. There is a high correlation between carcinogenicity and mutagenicity: 90% (157/175) of the carcinogens were mutagenic in the test, including almost all of the known humam carcinogens that were tested. Despite the severe limitations inherent in defining non-carcinogenicity, few non-carcinogens showed any degree of mutagenicity. Carcinogens negative in the test and apparent false positives are discussed. Evidence that chemical carcinogens and radiation, likely to initiate most human cancer and genetic defects, do so by damage by DNA is also discussed. The Salmonella test can play a central role in a program of prevention: to indentify mutagenic chemicals in the environment (all indications are there are many) and to aid in the development of non-mutagenic products to prevent future human exposure.