UNITED STATES, Aug. 19 (Nationwide Times) — People who work as pilots or flight attendants do not need to assume that every flight creates a major cancer danger. But a new study found that these two occupations had the highest shares of deaths from a group of cancers linked to radiation among 503 jobs in the United States.
The study found that 6.9% of deaths among flight attendants and 6.7% of deaths among pilots were linked to radiation-related cancers. Those figures describe the share of deaths in each occupation, not the chance that an individual worker will develop cancer.
The researchers said the findings point to a possible workplace exposure that deserves more study and discussion. They do not show that cosmic radiation caused the cancers.
What did the study examine?
Published Aug. 17, 2026, in JAMA Internal Medicine, the study 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, which summarized the research.
The researchers compared deaths from cancers classified as radiation-related with deaths from other cancers. The categories included breast cancer, melanoma, leukemia other than chronic lymphocytic leukemia, lymphoma, multiple myeloma, thyroid cancer, prostate cancer, central nervous system cancers and non-melanoma skin cancer.
Flight attendants had the highest proportion of radiation-related cancer deaths in the comparison. Pilots had the second-highest proportion. The study also found statistically higher mortality from several specific cancers among pilots and flight attendants, including breast cancer, central nervous system cancers, prostate cancer and melanoma. Pilots also had higher leukemia mortality, according to summaries of the study.
For cancers not classified as radiation-related, the mortality results for pilots and flight attendants were close to the middle of the occupations studied. That pattern was one reason the researchers focused on possible radiation exposure rather than treating the results as evidence that aircrew members face a higher risk from all cancers.
Why would airline workers encounter radiation?
At commercial flight altitudes, people are exposed to cosmic radiation, which comes from outer space and passes through the atmosphere. The atmosphere provides less protection at high altitudes than it does on the ground.
The Centers for Disease Control and Prevention estimates cited in coverage of the study put annual exposure for U.S. airline workers at about 3 to 6 millisieverts. A millisievert is a unit used to measure the biological effect of ionizing radiation.
For comparison, the CDC estimate cited in the study coverage said that 10 round-trip cross-country flights would result in about 0.4 millisieverts of exposure. A person who takes occasional flights therefore has a much different exposure pattern from someone who spends a career in the air.
The study authors wrote that aircrew members receive the largest average annual dose of ionizing radiation of any U.S. occupational group, mainly because of cosmic rays encountered during commercial flights.
What can the findings tell workers and travelers?
The results are most relevant to people with repeated, long-term occupational exposure, rather than to occasional airline passengers. They do not establish that a particular flight, route or airline causes cancer.
Harvard Medical School reported that senior author Anupam Jena said the findings support considering workplace radiation protections for U.S. aircrew members that match their level of exposure.
The study does not provide enough information to calculate an individual worker’s absolute cancer risk from the job. The published summaries also do not show whether the occupation listed on a death certificate was a person’s current or lifetime job, or fully explain how factors such as smoking and other health risks were handled.
Because the research was observational, it could identify an association but could not prove cause and effect. Differences in health, work history or other characteristics between occupations could also contribute to the results.
How does this fit with other research on jobs and cancer?
The aircrew findings are part of a broader effort to examine how working conditions may affect cancer mortality. 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 research, summarized by the University of Washington School of Public Health, found that cancer mortality patterns varied across occupations. Its co-author Marissa Baker said the findings were evidence that some jobs may expose workers to greater cancer risks than others.
Neither study means that occupation alone determines whether someone will get cancer. The aircrew study instead raises a narrower question: whether repeated exposure to cosmic radiation, along with other features of airline work, may help explain the higher share of radiation-related cancer deaths seen among pilots and flight attendants.
