Flight attendants and pilots face the highest risk of dying from cancers linked to radiation exposure—higher even than workers who handle radioactive materials, according to a study published in JAMA Internal Medicine.
Cosmic radiation at cruising altitude
Cosmic radiation comes from space. Earth’s atmosphere blocks most of it, but exposure rises at the altitudes where airplanes fly. While the general population absorbs minimal doses, frequent flyers—especially crew members—accumulate more over time.
The study examined over 12 million U.S. death certificates, focusing on occupations listed at the time of death. The team tracked cancers with known ties to radiation, including leukemia, lymphoma, multiple myeloma, and cancers of the skin, breast, thyroid, prostate, and central nervous system.
Of more than 500 occupations, flight attendants had the largest share of deaths from these cancers. Pilots followed closely. The increased risk applied to almost every type of radiation-linked cancer in both groups.
Risk of death from cancer 50% higher for flight attendants
Flight attendants were about 50% more likely to die from a radiation-related cancer than the general working population. Pilots faced a 36% higher risk. In total, 6.9% of flight attendant deaths resulted from these cancers—roughly one in 14. For pilots, the share was 6.7%. The average for all workers stood at 5%.
Dr. Vishal Patel of Harvard Medical School, who led the study, said the results remained consistent even after excluding cancers not tied to radiation. That consistency, he explained, points to occupational exposure rather than lifestyle or socioeconomic factors as the cause.
The data has limitations. The team lacked details on individual exposure levels, whether from flights or other sources. Some death certificates may have misclassified occupations. The study also couldn’t separate the effects of disrupted sleep cycles, a known cancer risk for shift workers like flight crews.
Federal regulators have long recognized that aircrews are exposed to ionizing radiation. The U.S. still has no mandatory dose limits or monitoring for these workers. “You can’t manage an exposure you’ve decided not to measure,” Patel said.
The findings support concerns raised for years by flight attendant unions. Sara Nelson, president of the Association of Flight Attendants-CWA, said the report validates what crews have long argued: the risk exists, but no one is held accountable. “No one is taking responsibility,” she said.
In an accompanying commentary, Australian radiation experts Catherine Olsen and Ken Karipidis suggested that flight crews might benefit from earlier or more frequent cancer screenings. They proposed annual skin exams for all high-altitude workers and earlier mammograms for women in those roles. Doctors treating pilots and flight attendants, they added, should consider cancer more often when evaluating symptoms.
The study’s use of death certificates means it only captures fatal cases. It doesn’t include cancers that were treated successfully or workers who left the industry before developing symptoms. The data also predates modern aircraft designs, which may change exposure levels.
Earlier research on aviation radiation risks suffered from small sample sizes. This study’s scale—covering millions of records—provides stronger evidence, though questions remain about safe exposure limits. Without tracking individual doses, regulators and airlines lack a clear basis for setting safety standards.
For now, workers bear most of the responsibility for managing risk. Some airlines offer voluntary radiation monitoring, but not all crew members participate. Others provide health screenings, though these depend on the carrier and union agreements. The absence of consistent protections forces many to handle the risks independently.
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