U.S. pilots and flight attendants face the highest risk of radiation-related cancer deaths among more than 500 occupations studied, according to a Harvard study published in JAMA Internal Medicine.
The research analyzed nearly 13 million U.S. death certificates from 2020 to 2024, identifying 14,000 pilots and 7,000 flight attendants. The study focused on mortality from radiation-related cancers, including breast cancer, multiple myeloma, leukemia (excluding chronic lymphocytic leukemia), lymphoma, central nervous system cancers, thyroid cancer, prostate cancer, melanoma, and non-melanoma skin cancers. Lung cancer was excluded to avoid confounding results with smoking-related risks.
Pilots and flight attendants demonstrated statistically significantly higher mortality rates for breast cancer, central nervous system cancers, prostate cancers, and melanoma. Pilots also showed a higher likelihood of death from leukemia. Specifically, 6.9% of deaths among flight attendants and 6.7% of deaths among pilots were linked to radiation-related cancers, rates higher than those observed in any other occupation analyzed.
"As you get high up in the atmosphere, you're exposed to ionizing radiation from the sun – it's called cosmic radiation," explained study author Anupam B. Jena, M.D., Ph.D. The study notes that for cancers not related to radiation, the mortality rates for these professions were comparable to other occupations, suggesting that the elevated risk is specifically linked to radiation exposure.
Annual radiation exposure for airline workers is estimated between 3 to 6 millisieverts, significantly higher than the approximately 0.4 millisieverts received by individuals taking 10 round-trip cross-country flights. This means airline workers can accumulate roughly eight to 15 times the annual cosmic radiation exposure of a frequent flyer.
Jena suggested that the cumulative nature of radiation risk implies that longer exposure times in the air could lead to a greater increase in cancer risk. The findings raise questions about the need for additional or earlier cancer screenings for pilots and flight attendants. "I think the level of screening may need to be higher," Jena stated, adding that regular screenings and potentially earlier screening initiation are considerations. He emphasized that the study reflects group-level risk rather than dictating the risk for any individual pilot or flight attendant.
The study acknowledges limitations, including its observational nature, which prevents establishing a causal link between cosmic radiation and elevated cancer mortality, only an association. Furthermore, the researchers lacked data on individual workers' radiation exposure levels, making it impossible to determine if greater exposure correlated with higher risk. Other occupational or lifestyle factors could also play a role in the observed outcomes. For individuals who fly frequently for reasons other than employment, Jena indicated the findings should be less concerning, as few passengers accumulate flight time comparable to aviation professionals.