Cancer incidence among Norwegian airline cabin attendants

Background Cabin crews are exposed to cosmic radiation at work and this may increase their incidence of radiation-induced cancers. Former studies indicate an increased risk of breast cancer. Methods A retrospective cohort study was performed. The cohort was established from the files of the Civil Aviation Administration and included people with a valid licence as a cabin attendant between 1950 and 1994. The cohort was linked to the Cancer Registry of Norway. Observed number of cases was compared with expected, based on national rates. Breast cancer incidence was analysed, adjusting for individual fertility variables. Results A group of 3693 cabin attendants were followed over 72 804 person-years. Among the women, 38 cases of breast cancer were observed (standardized incidence ratio (SIR) = 1.1, 95% CI: 0.8-1.5). Among men excess risks were found for cancers in the upper respiratory and gastric tract (SIR = 6.0, 95% CI: 2.7-11.4) and cancer of the liver (two cases, SIR = 10.8, 95% CI: 1.3-39.2). For both sexes elevated risks were found for malignant melanoma and non-melanoma skin cancer, for men these were SIR = 2.9 (95% CI: 1.1-6.4) and SIR = 9.9 (95% CI: 4.5-18.8) respectively, while for women these were SIR = 1.7 (95% CI: 1.0-2.7) and SIR = 2.9 (95% CI: 1.0-6.9) respectively. For no cancer site was a significant decreased risk found. Conclusions An increased risk of radiation-induced cancers was not observed. The excess risks of some other cancers are more probably explained by factors related to lifestyle.