Transformation of BALB/c 3T3 Cells in vitro by the Fungicides Captan, Captafol and Folpet

Cytotoxic and cell‐transforming activities of the three fungicides, captan, captafol and folpet, have been studied in an experimental in vitro model by exposing BALB/c 3T3 cells to the chemicals with or without S‐9 mix‐induced bioactivation. Cytotoxicity of the three compounds was reduced in the presence of the metabolizing system. Each assayed pesticide displayed cell‐transforming ability in the presence of the metabolizing system. The relative efficiency was: captafol > captan < folpet. Cell transformation was considered to be due to carcinogenesis‐promoting activity. These data, obtained in a medium‐term (6‐8 weeks) experimental model, contribute to a better understanding of the action of the three pesticides in the multistep carcinogenesis process and provide more information concerning the oncogenic risk of these xenobiotic compounds for humans.