This report provides the findings of a ten-month study of a possible cancer cluster among fire fighters in Anne Arundel County, Maryland. Fire fighters are exposed to smoke generated by the combustion of diverse materials, and the smoke is known to contain carcinogens. Consequently, several decades of research have been directed at risk for cancer among fire fighters, as well as for other chronic diseases, particularly non-malignant respiratory diseases. This report originated with a specific request from the Maryland Department of Health and Mental Hygiene (DHMH) concerning a possible cancer cluster among fire fighters in Anne Arundel County. The exposure of specific concern was to smoke generated by training fires at the Anne Arundel County Training Facility. For a period of 9 years, reportedly from 1971-1979, the training fires used waste oils provided by BGE that were contaminated with polychlorinated biphenyls (PCBs). Consequently, a substantial number of fire fighters and instructors were exposed to PCBs and compounds generated by their combustion.