"In this first phase of examining health effects in career firefighters, we report on mortality and cancer incidence among nearly 30,000 career firefighters followed from 1950 through 2009. Compared with the US population, we found small to moderate increases in risk for several cancer sites and for all cancers combined, stemming mostly from excess malignancies of the respiratory, digestive and urinary systems in otherwise healthy individuals... NIOSH researchers found that, when compared to the number of cancers expected using U.S. population rates, the firefighters in this study had a modest increase in cancer diagnoses (9% increase) and cancer-related deaths (14% increase)..."
Daniels, Robert D, et al. “Mortality and cancer incidence in a pooled cohort of US firefighters from San Francisco, Chicago and Philadelphia (1950- 2009).”
, 13 Oct. 2013. CDC.