Flight attendants and pilots had the highest adjusted proportion of deaths from radiation-related cancers among more than 500 occupations in a new JAMA Internal Medicine analysis.
Flight attendants had about 50% higher adjusted odds of dying from these cancers, while pilots had 36% higher odds, compared with the broader working population. Importantly, the study found much less evidence of excess mortality from cancers not associated with radiation.
The findings strengthen concerns about long-term cosmic radiation exposure among aircrew, but they do not prove that radiation caused these cancers. The researchers had no individual radiation-dose histories and could not fully account for other occupational exposures such as circadian disruption.
Study Details
Cosmic radiation originates outside Earth and becomes more intense as altitude increases because there is less atmosphere available to shield people from it. Commercial aircrew therefore receive repeated low-dose ionizing radiation exposure while working at cruising altitude.
FAA guidance recognizes cosmic radiation as an occupational exposure for aircrew. Radiation dose varies with altitude, latitude, time in the air, and solar activity, with higher exposure generally occurring at higher altitudes and closer to the poles.
The new research was published online August 17, 2026, by Vishal Patel, MD, MPH, Michael Liu, MD, MPhil, and Anupam Jena, MD, PhD. The investigators wanted to determine whether the unusually high radiation exposure of pilots and flight attendants was reflected in cancer mortality.
Methodology
Researchers analyzed U.S. death certificates from the National Vital Statistics System between 2020 and 2024. The dataset included about 12.7 million deaths across 503 occupations, including approximately 14,000 pilots and 7,000 flight attendants.
The investigators classified several cancers as radiation-related, including breast cancer, central nervous system cancers, multiple myeloma, most leukemias, lymphoma, thyroid cancer, prostate cancer, melanoma, and nonmelanoma skin cancer. Lung cancer was excluded from this group because smoking could create substantial confounding.
The analysis adjusted for age at death, sex, race, ethnicity, education, and marital status. Aircraft mechanics and assemblers were used as negative controls because they work around aircraft without sustained high-altitude exposure, while nuclear technologists served as a positive control because occupational radiation exposure is already established in that profession.
Key Findings
Flight attendants ranked first among all occupations studied. About 6.9% of their deaths were attributed to cancers classified as radiation-related, compared with roughly 5% across the general working population. Their adjusted odds were 50% higher.
Pilots ranked second. About 6.7% of pilot deaths involved radiation-related cancers, with adjusted odds approximately 36% higher than the comparison population.
The pattern appeared across multiple cancer types. Elevated associations were seen for cancers including breast, prostate and central nervous system cancers and melanoma, while pilots also showed higher leukemia mortality.
The signal was much weaker for other cancers. Aircrew did not show the same broad increase in cancers classified as unrelated to radiation, an observation the accompanying commentary said supports, but does not establish, the occupational radiation hypothesis.
What This Means for Aircrew and Clinicians
The most important caution is that this is a mortality study, not a radiation-dose study. Saying that 6.9% of flight attendant deaths involved radiation-related cancers does not mean cosmic radiation caused 6.9% of flight attendant deaths. The study shows a strong occupational association that now requires more direct exposure research.
Aircrew have other potentially relevant exposures. Pilots may receive ultraviolet exposure through cockpit windows, while both pilots and flight attendants experience night work, irregular schedules, sleep disruption, and repeated crossing of time zones. The JAMA commentary specifically identifies cosmic radiation, UV-A exposure, and circadian disruption as overlapping concerns.
For clinicians, occupational history may therefore matter more than previously appreciated when caring for career pilots and flight attendants. The commentary argues for greater clinical awareness when evaluating potentially cancer-related symptoms. It also raises the possibility of more deliberate skin surveillance and individualized discussions about breast cancer screening, although this study by itself is not sufficient to create a new screening guideline.
The policy question may be even larger. FAA guidance already provides methods for estimating cosmic radiation exposure and recommends occupational exposure limits, including a five-year average effective dose of 20 mSv per year for nonpregnant crewmembers. Yet the new study authors note that U.S. commercial aircrew are not routinely subject to the kind of federal individual dose-monitoring system used in some other radiation-exposed workplaces.
The next step should be prospective research that connects actual flight histories and estimated cumulative radiation doses with long-term cancer incidence and mortality. That would help answer the question this study cannot: whether greater cumulative cosmic radiation exposure produces a measurable dose-response increase in cancer risk.