UNITED STATES, Aug. 19 (Nationwide Times) — People who work as pilots or flight attendants may face higher rates of death from some cancers than workers in other occupations, according to a U.S. study published in JAMA Internal Medicine. The finding does not show that flying causes cancer, and it does not mean that every airline worker faces a high personal risk.
For most people, the study is not a reason to change ordinary travel plans. For current or former aircrew members, however, the researchers said the results support a closer look at workplace exposure to cosmic radiation and occupational protections.
What did the study find?
Researchers analyzed nearly 13 million U.S. death certificates from 2020 through 2024. The records covered 503 occupations, including about 14,000 pilots and 7,000 flight attendants, according to Harvard Medical School’s summary of the study.
The study classified several cancers as radiation-related, including breast cancer, leukemia, melanoma, thyroid cancer, prostate cancer, lymphoma, multiple myeloma, central nervous system cancers and non-melanoma skin cancers.
Among people who had worked as flight attendants, 6.9% of deaths were linked to cancers in those categories. The corresponding figure for pilots was 6.7%. Those were the two highest proportions among the occupations studied, according to the study’s analysis of National Vital Statistics System records.
The researchers also reported significantly higher mortality from breast cancer, central nervous system cancers, prostate cancer and melanoma among pilots and flight attendants. Pilots also had higher leukemia mortality, according to reports summarizing the study.
The figures describe the share of deaths in the occupation linked to the selected cancers. They are not the chance that an individual pilot or flight attendant will develop cancer. The study did not provide absolute cancer risks for individual workers in the supplied findings.
Why might aircrew be exposed to radiation?
At commercial flight altitudes, workers are exposed to cosmic radiation, which comes from space and passes through the atmosphere. The study authors wrote that aircrew members receive the largest average annual dose of ionizing radiation of any U.S. occupational group, primarily because of that exposure.
The exposure depends on factors such as time spent flying and flight altitude. The Centers for Disease Control and Prevention comparison cited in coverage of the study estimates that U.S. airline workers receive about 3 to 6 millisieverts of cosmic radiation each year. A person taking 10 round-trip cross-country flights would receive about 0.4 millisieverts, according to the same comparison.
That comparison does not establish that a particular worker’s cancer was caused by radiation. It describes exposure levels across groups; individual exposure can vary.
Does the study prove that flying causes cancer?
No. The study was observational, meaning researchers examined patterns in existing records rather than assigning people to different exposure levels. That design can identify an association but cannot prove that cosmic radiation caused the higher cancer mortality.
The supplied study summaries do not show whether occupation referred to a person’s current or lifetime job. They also do not provide information about individual flight hours or radiation doses, or fully explain how factors such as smoking and other possible influences were handled. Those gaps make it difficult to determine how much of the difference was related to flying itself.
The researchers found that pilots and flight attendants had cancer mortality rates near the middle of the occupational range for cancers not classified as radiation-related. That pattern was not seen among ground-based aviation workers, according to the study summary. The contrast supports the researchers’ focus on occupational exposure, but it still does not establish cause and effect.
Senior author Anupam Jena, a Harvard Medical School health policy professor, said the findings support considering occupational radiation protections for U.S. aircrew members that match their level of exposure.
How should the findings be understood?
Cancer is influenced by many factors, including age, genetics, environment and behavior. A study comparing occupations cannot by itself separate all of those influences. Also, a higher relative risk can correspond to a small absolute difference when the underlying risk is low; the aircrew study’s supplied findings do not provide the absolute numbers needed to measure that difference.
A separate study published in January 2026 in The Lancet Oncology examined nearly 500,000 cancer deaths among working-age U.S. adults from 2020 through 2023. Researchers from Ohio State University and the University of Washington calculated age-adjusted cancer mortality rates by sex for more than 400 occupations. That work also found differences among occupations, but it was a separate analysis and does not establish that airline work causes cancer.
Taken together, the studies point to occupation as a factor researchers can examine when studying cancer patterns. For airline workers, the Harvard-led study raises a workplace-health question about long-term cosmic-radiation exposure. It does not, on its own, show that flying is a crisis for workers or passengers.
