Study Finds Flight Crews Face Highest Risk of Radiation-Linked Cancer Deaths in US

A large-scale study published in JAMA Internal Medicine by Harvard Medical School researchers has revealed that flight attendants and pilots in the United States have the highest mortality rates from cancers associated with ionizing radiation exposure. The study analyzed death certificate data from nearly 13 million people across 503 occupations between 2020 and 2024, including about 14,000 pilots and over 7,000 flight attendants. Researchers focused on cancers linked to ionizing radiation, such as leukemia, lymphoma, multiple myeloma, breast, thyroid, prostate, central nervous system cancers, and melanoma.

Results showed that 6.9% of deaths among flight attendants and 6.7% among pilots were due to these cancers, compared to approximately 5% in the general working population. After adjusting for age, sex, education, and demographics, flight attendants had a 50% higher risk of death from these cancers, and pilots had a 36% higher risk. Flight attendants ranked first and pilots second among all occupations studied, surpassing nuclear technicians who ranked 12th despite known radiation exposure in their work.

The study also found significant increases in deaths from breast cancer, central nervous system cancer, prostate cancer, and melanoma among flight crews, with pilots also showing increased leukemia deaths. No similar increase was observed for cancers not typically linked to radiation. Experts suggest cosmic ionizing radiation at high altitudes as the likely cause, as Earth's atmosphere offers less protection at flight levels around 10 kilometers. Factors influencing exposure include flight altitude, latitude, duration, and solar activity.

The US Centers for Disease Control and Prevention (CDC) has acknowledged elevated melanoma and breast cancer risks among flight crews but notes uncertainty about the exact role of radiation versus other factors. A June 2024 report by US National Academies called for the Federal Aviation Administration (FAA) to recognize ionizing radiation as an occupational hazard, implement monitoring systems, and require airlines to adopt safety programs. Currently, the FAA does not mandate exposure limits or routine monitoring for flight crews, unlike some European countries.

The lead author, Dr. Vishal Patel, emphasized the challenge: "You cannot manage exposure you choose not to measure." Sarah Nelson, president of the Association of Flight Attendants-CWA, said the findings support long-standing union concerns about insufficient information and training on radiation risks. Limitations of the study include lack of data on individual flight hours, routes, cumulative radiation doses, and inability to separate radiation effects from circadian rhythm disruptions common in flight crews.

In Israel, authorities recognize the risk but do not require mandatory monitoring of cosmic radiation exposure for all pilots and flight attendants. A 2014 occupational safety guideline recommends exposure assessment and flight planning considerations but is not legally binding. Aviation regulations require record-keeping of cosmic radiation doses only for flights above 49,000 feet to calculate cumulative exposure over 12 months.