Retrospective study of cancer-related mortality among US pilots and flight attendants

Aircrew members receive the largest mean annual effective dose of ionizing radiation of any occupational group in the US, primarily due to cosmic rays encountered at commercial flight altitudes. A retrospective study using the National Vital Statistics System (2024) investigated whether pilots and flight attendants have elevated cancer mortality compared with other occupations. The study evaluated radiation-related cancers (breast, central nervous system, multiple myeloma, leukemia except CLL, lymphoma, thyroid, prostate melanoma, and non-melanoma skin cancers; lung cancer was excluded to reduce potential confounding given its association with smoking) and non-radiation-related cancers (all other cancers). As a positive control group, nuclear technologists were evaluated for radiation-related cancer and as a negative control group, aircraft assemblers and aircraft mechanics were evaluated. The study identified 12 710 517 decedents across 503 occupations. Flight attendants (6.9%; 95% CI 6.4-7.5) and pilots (6.7%; 6.3-7.1) had the highest and second-highest risk-adjusted percentage of death from radiation-related cancers. This patterns was not observed for non-radiation cancers, for which aircrew ranked near the median of all occupations. Aircrew mechanics and aircraft assemblers did not show elevated radiation-related cancer mortality compared with the other occupations, whereas nuclear technologist had the 12th highest percentage of radiation-related cancer deaths, consistent with their established ionizing radiation exposure.