Tumorigenic activity of lead chromate.

Lead chromate was investigated for its carcinogenic potential in both rats and mice. Results show that this compound is a very potent carcinogen in rats when administered i.m. Sixty-four % of the animals treated developed malignant tumors at the injection site. Three renal carcinomas were also found after i.m. treatment with lead chromate. Since lead powder is a comparatively weak carcinogen in rats, whether given p.o. or i.m., it is suggested that the combination of lead and chromium (also weak carcinogen) accounts for the high carcinogenic activity of lead chromate in rats. Swiss albino female mice could not tolerate the same high dose level as did the rats; at the lower dose administered to the mice, no tumors were detected.