UNITED STATES, Aug. 19 (Nationwide Times) — For most airline passengers, the findings of a new U.S. study do not provide a reason to change ordinary travel plans. The study looked at deaths among people who worked as pilots or flight attendants over several years. It found that these workers had a higher share of deaths from certain cancers than workers in many other occupations—but it did not prove that flying-related radiation caused those deaths or show an individual worker’s chance of developing cancer.
The study, published Aug. 17, 2026, in JAMA Internal Medicine, 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 research.
Among the occupations studied, flight attendants had the highest proportion of deaths classified as radiation-related cancers. Pilots ranked second. About 6.9% of deaths among flight attendants and 6.7% of deaths among pilots were linked to those cancer categories, according to the study’s analysis of National Vital Statistics System records.
Those figures are proportions of deaths, not the percentage of workers who will develop cancer. The study did not provide the absolute cancer mortality rates or an individual worker’s risk. A higher proportion can also reflect differences among occupations in age, sex, smoking, access to health care and other factors.
What cancers were included?
The researchers grouped several cancers under the study’s radiation-related category. They included breast cancer, melanoma and non-melanoma skin cancers, leukemia other than chronic lymphocytic leukemia, multiple myeloma, lymphoma, thyroid cancer, prostate cancer and cancers of the central nervous system.
Pilots and flight attendants had significantly higher mortality rates for breast cancer, central nervous system cancers, prostate cancer and melanoma, according to reports on the study’s findings. Pilots also had higher leukemia mortality.
The pattern was not seen across all cancers. For cancers classified as non-radiation-related, the mortality rates for pilots and flight attendants were comparable with those of other occupations. The researchers also reported that ground-based aviation workers did not show the same pattern.
Why might aircrew face more radiation exposure?
At commercial flight altitudes, workers are exposed to cosmic radiation, which comes from space and passes through the atmosphere. The Centers for Disease Control and Prevention is cited as estimating that U.S. airline workers receive about 3 to 6 millisieverts of cosmic radiation each year. A millisievert is a unit used to measure exposure to ionizing radiation.
For comparison, the exposure from 10 round-trip cross-country flights is about 0.4 millisieverts, according to the CDC comparison cited in reports on the study. Airline workers generally spend far more time at cruising altitude than occasional passengers do.
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 at commercial flight altitudes.
That exposure is one possible explanation for the findings, but the study did not directly measure each worker’s flight hours or radiation dose, according to the study’s reported limitations. The researchers also could not establish from the death-certificate data whether cosmic radiation caused the cancers.
Harvard Medical School senior author Anupam Jena said the findings support considering “occupational radiation protections for U.S. aircrew members commensurate with their level of exposure.”
What does the study mean for workers and passengers?
The study is observational. That means it compared patterns in existing records rather than assigning people to jobs or tracking their exposures in a controlled experiment. Observational studies can identify associations, but they cannot by themselves prove cause and effect.
The records also do not answer several questions, including whether the occupation listed was a person’s current or lifetime job, how smoking and other possible confounding factors were handled, and whether cancer risks differed according to years of employment or number of flights.
As a result, the findings describe a population pattern rather than a personal forecast. They may be relevant to discussions about workplace monitoring and protections for aircrew, but they do not show that a particular pilot or flight attendant will develop cancer. They also do not measure cancer risk from occasional air travel.
How does this fit into broader research on jobs and cancer?
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 study, summarized by the University of Washington School of Public Health, found that cancer mortality varied among occupations. Co-author Marissa Baker said the findings were evidence that some jobs may expose workers to higher cancer risks than others.
Together, the studies point to the value of examining workplace conditions. But neither study means that occupation alone determines a person’s cancer risk. The aircrew study in particular found an association in death records and did not establish that cosmic radiation was the cause.
