Oncogenic Hazard from Chronic Inhalation of Hydrazine

摘要

Studies were therefore conducted to evaluate the long-term effects of airborne hydrazine at levels near the present and proposed Threshold Limit Value concentrations. Repeated daily inhalation exposure to 5 parts per million (ppm) hydrazine induced nasal tumors in Fischer 344 male and female rats and in male Golden Syrian hamsters. Repeated exposure to 1 ppm also produced nasal turbinate tumors in rats and pulmonary adenomas in female C57B1/6 mice. The inhalation exposures to the rodents were conducted for an additional 12-month postexposure observation period and the survivors were necropsied. Rats and mice were held 18 months postexposure. The nasal turbinate tumor incidence in rats was dose related. Increased tumor incidence occurred in both mice and hamsters at the maximum tolerated repeated inhalation dose. No statistically significant tumorigenic effects occurred after repeated exposure to 0.05 and 0.25 ppm hydrazine concentrations which spanned the American Conference of Governmental Industrial Hygienists recommended Threshold Limit Value.