Cancer

Abstract

Firefighters were long suspected to have an excess risk of cancer but most investigators assumed that the site of greatest signifi cance would be lung cancer. Early modern studies showed relatively low elevations, if any, in cancer risk overall and elevations in several sites other than lung, but only modest excesses in lung cancer, of a magnitude (roughly150 % expected) common to many occupations, including many without exposure to fi re smoke [1 ]. This excess was usually (but not convincingly) apportioned to cigarette smoking. As research fi lled in the gaps, however, this picture from the 1970s and 1980s turned out to be false and a new synthesis emerged: a real elevation due to occupation is obscured by lower individual risks among fi re department members compared to the general population, which is the usual reference population for comparison. The pattern of their cancer risk should be well below the general population, given fi refi ghters’ profile of risk factors (including smoking). Instead, the absence of a strong healthy worker “lifestyle” effect overall, the elevations that become visible when internal reference groups are used (based on exposure), andthe profi le of cancers involved (mostly at sites plausibly associated with carcinogen exposure) all suggest that fi refi ghters do indeed have an elevation in risk for cancers arisingfrom their occupation but that this is offset because their smoking and other lifestyle factors should place them at lower risk than the general population. Furthermore, for some cancers the elevations are suffi ciently strong and consistent among well-designed studies andrelevant subgroups to have given rise to legislated presumptions. The cancers most often accepted as being associated with fi refi ghting are kidney, bladder, testicular, leukemia, non-Hodgkin lymphoma (itself actually a family of cancers), brain, colon and rectum, and prostate.