Effects of subtoxic levels of lead and cadmium on urogenital organs of male rats.

Higher incidence of prostate cancer among lead and cadmium smelter workers has been reported. Forty male rats were divided into four groups. Group I served as control; Group II was injected intraperitoneally, close to the site of the prostate, with 0.05 mg lead acetate; Group III was injected with 0.05 mg cadmium chloride; and Group IV was injected with a combination of 0.025 mg lead and 0.025 mg cadmium chloride. After daily injection for one month, lead and cadmium had a synergistic effect on testicular damage and prostatic cytology; although no tumor formation was observed in the prostate, there was replacement of columnar epithelium by squamous epithelium, suggestive of progressive, precancerous changes. There was an increase in incidence of stone formation in the kidney and urinary bladder.