Incidence of cancer among female flight attendants: a meta-analysis.

Background. Airline flight personnel work in a unique enviromnent with exposure to known or suspected carcinogens and mutagens including ionizing cosmic radiation. A meta-analysis was conducted to study whether the occupational exposure of female flight attendants (FA) increased their relative risk of cancer incidence. Methods. A bibliographical computer search from 1966 to 2005 of cancer incidence cohort studies of female FA was performed. Combined relative risks (RRc) in cancer incidence were calculated by means of meta-analysis. Results. RRc and 95% confidence interval (CI) for malignant melanoma and breast cancer in female FA were 2.13 (95% CI: 1.58-2.88) and 1.41 (1.22-1.62) (p < 0.0001). Excess risk,,vas not significant for all-site cancer with RRc of 1.10 (0.99-1.21). uConclusions. The meta-analysis confirmed the significantly increased risks for malignant melanoma and breast cancer in female FA. Increased exposure to cosmic radiation during flight has been suggested as a potential occupational risk factor. Ultraviolet radiation exposure on board seems an unlikely occupational risk, but nonoccupational leisure time sun exposure is a possible risk factor. The etiology of the observed increase in incidence of some cancers remains controversial because assessment of possible confounders, especially nonoccupational exposure factors, has thus far been limited.