Cancer incidence and mortality among flight personnel: A meta-analysis

Background: Increased cancer risk among flight personnel have previously be en noted, including breast cancer among flight attendants and acute myeloid leukemia among pilots. Hypothesis: Exposure to cosmic radiation and other physical or chemical agents may pose health risks for flight personnel. Met hods: We performed an exhaustive search for published and unpublished cohor t studies of flight personnel from 1986-98. We combined relative risks (RR) for selected causes from lour mortality and/or incidence studies of pilots and two incidence studies of flight attendants, using standard meta-analyt ic methods. Heterogeneity among the combined studies was explored and adjus tments were made for possible confounding by socioeconomic status (SES). wh ere indicated, using correction factors from published studies. Results: SE S-adjusted combined RRs were elevated (>1.2) among male pilots for mortalit y from melanoma [1.97 (95% CI: 1.02-3.82)] and brain cancer [1.49 (0.89-2.2 0)], and for cancer incidence of the prostate [1.65 (1.19-2.29)] and the br ain [1.74 (0.87-3.30)]. Among female flight attendants, increases were seen for incidence of all cancers [1.29 (0.98-1.70)], melanoma [1.54 (0.83-2.87 )], and breast cancer [1.35 (1.00-1.83)]. Conclusions: Flight personnel app ear to be at increased risk for several types of cancer. Both occupational exposures and well-established nonoccupational risk factors may contribute to this increased risk. To better control for confounding factors and to id entify exposures potentially amenable to preventive measures, future studie s should compare risks within cohorts by flight routes, work history, and e xposure to cosmic and UV radiation, electromagnetic fields, and chemical su bstances.