Benzene: epidemiologic observations of leukemia by cell type and adverse health effects associated with low-level exposure.

Benzene has been known to be a bone marrow poison for almost a century. However, it was not until the last decade that benzene's carcinogenic potential was demonstrated by epidemiologic studies. The proposed regulation by the Occupational Safety and Health Administration (OSHA) to lower exposure levels of benzene in the workplace, and the court challenges that followed, have made the evidence of benzene toxicity a frequent topic of discussion and analysis. Epidemiologic evidence of leukemia risk associated with benzene exposure is summarized, including a discussion of certain contentions raised during the OSHA hearing. Special attention is given to information on specific cell types of leukemia associated with benzene and to qualitative and quantitative assessments of health risks associated with low-level benzene exposure.