UNITED STATES, Aug. 19 (Nationwide Times) — For most people, the findings do not mean that an occasional flight is a major cancer danger. The study examined people who worked in aviation, often over long periods, and found an association between airline jobs and certain cancer deaths. It did not show that flying caused those cancers or establish an individual passenger’s risk.
The study, published Aug. 17, 2026, in JAMA Internal Medicine, analyzed nearly 13 million U.S. death certificates from 2020 through 2024. It compared 503 occupations, including about 14,000 pilots and 7,000 flight attendants, according to Harvard Medical School’s summary of the research.
Among the occupations studied, flight attendants had the highest proportion of deaths classified as radiation-related cancers. Pilots had the second-highest proportion. About 6.9% of deaths among flight attendants and 6.7% of deaths among pilots were in those cancer categories, according to the study’s analysis of National Vital Statistics System records.
What the study measured
The researchers grouped several cancers as radiation-related for the analysis. The list included breast cancer, leukemia excluding chronic lymphocytic leukemia, lymphoma, multiple myeloma, melanoma, non-melanoma skin cancers, thyroid cancer, prostate cancer and cancers of the central nervous system.
Pilots and flight attendants had statistically significant increases in mortality from breast cancer, central nervous system cancers, prostate cancer and melanoma, according to reports on the study. Pilots also had higher leukemia mortality.
The pattern was different for cancers the researchers classified as non-radiation-related. Aircrew rates for those cancers were comparable with those in other occupations, and were near the middle of the occupational range.
That contrast was important to the researchers because it pointed to a possible workplace exposure rather than a broad difference in overall cancer mortality. But the study could not prove that exposure caused the higher mortality.
Why airline work involves radiation
At commercial flight altitudes, workers are exposed to cosmic radiation, a form of ionizing radiation that comes from space. The atmosphere provides less protection at those altitudes than it does on the ground.
The Centers for Disease Control and Prevention figures cited in reports on the study put annual cosmic-radiation exposure for U.S. airline workers at about 3 to 6 millisieverts. For comparison, 10 round-trip cross-country flights were estimated at about 0.4 millisieverts.
Because pilots and flight attendants may spend many hours in the air each year, their cumulative occupational exposure can be higher than that of occasional travelers. The study authors wrote that aircrew members receive the highest average annual effective dose of ionizing radiation of any U.S. occupational group, mainly because of cosmic rays at commercial flight altitudes.
Harvard Medical School senior author Anupam Jena said the findings support considering occupational radiation protections for U.S. aircrew members in line with their exposure.
What the study cannot tell us
The research was observational. That means it identified a pattern in existing records rather than assigning people to different levels of radiation exposure. Observational studies can find associations but cannot by themselves establish cause and effect.
The available study summaries do not provide individual flight hours, personal radiation doses or complete information about factors such as smoking and other possible differences between occupations. The summaries also do not provide absolute cancer mortality rates for pilots and flight attendants, so the percentages should not be treated as an individual’s chance of developing cancer.
The figures describe the share of deaths in selected categories among people identified with those occupations. A proportion of deaths is not the same measure as a person’s lifetime cancer risk or the risk from taking a particular flight.
How this fits with other job research
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 at Ohio State University, the University of Washington and other institutions calculated age-adjusted cancer mortality rates by sex for more than 400 occupations.
That broader research also found differences in cancer mortality across occupations. University of Washington associate professor and study co-author Marissa Baker said the findings showed that some occupations may expose workers to higher cancer risks than others.
Together, the studies suggest that occupation can be useful in public-health research. They do not mean that every worker in a higher-ranking occupation will develop cancer, nor do they identify a single cause for every cancer death.
For airline workers, the JAMA Internal Medicine study raises questions about long-term workplace exposure and the need for continued monitoring. For passengers, the study does not provide evidence that routine air travel creates the same level of exposure as an aviation career.
