Assessment of the risks associated with the use of chemical carcinogens in biomedical research.

Estimates of occupational exposure to chemical carcinogens in biomedical research based on environmental monitoring data, efficiency of containment devices, and accident data suggest that workers may be exposed to a few tenths of a microgram of these carcinogens per work day. Environmental exposure to carcinogenic polycyclic aromatic hydrocarbons and N-nitroso compounds exceeds one microgram per day. Because occupational exposure to chemical carcinogens in the laboratory can be readily controlled and because environmental exposure appears to be greater than the occupational exposure that does occur, the relative risk of occupational exposure does not seem to constitute a major health problem.