Carcinogenicity of captan.

Two studies on the carcinogenicity of the fungicide captan in animals were reviewed. The results and conclusions, which were based on my examination of the histological sections, showed that captan is highly carcinogenic in rats and mice. Neoplasms at all sites, as well as malignant neoplasms, were increased in both low and high dose captan-treated male and female rats. Benign and malignant neoplasms of the endocrine organs were increased in low and high dose male and female rats ingesting captan. Neoplasms of the adrenal and pituitary glands were increased. Increased incidences of benign and malignant neoplasms, and of malignant neoplasms only, were observed in the reproductive system of female rats ingesting captan. The incidence of these neoplasms was markedly increased in the mammary gland and ovary. Female rats given captan were more susceptible to the development of hepatic neoplasms than were male rats. Captan induced neoplasms of the duodenum in male and female mice. There also were toxic changes in rats. Captan-treated male rats were more susceptible to the induction of chronic renal disease than were female rats. Male rats also had a high incidence of particularly severe testicular atrophy as a result of the ingestion of captan. Such lesions interfere with the health of the rats and with the development of neoplasms.