Aircrews Face Highest Proportion of Radiation-Related Cancer Deaths Among 503 U.S. Occupations
核心洞察
A JAMA Internal Medicine study of nearly 13 million U.S. death certificates (2020–2024) found flight attendants and pilots had the highest and second-highest proportions of radiation-related cancer deaths among 503 occupations.
Radiation-related cancers accounted for 6.9% of deaths among flight attendants and 6.7% among pilots, exceeding nuclear technologists, who ranked 12th.
Aircrew accrue an estimated 3–6 millisieverts of cosmic radiation annually, roughly an order of magnitude above the 0.4 millisieverts received by an average frequent traveler.
Flight attendants and pilots have the highest and second-highest proportion of radiation-related cancer deaths among more than 500 occupations in the United States, according to a new study published August 17 in JAMA Internal Medicine. The findings support considering occupational radiation protections for U.S. aircrew members commensurate with their level of exposure, said senior author Anupam Jena, the Joseph P. Newhouse Professor of Health Care Policy in the Blavatnik Institute at Harvard Medical School, and colleagues.
The study, led by Vishal Patel, HMS clinical fellow in surgery at Brigham and Women's Hospital, drew on a single population-based data source—the National Vital Statistics System—examining all U.S. death certificates from 2020 to 2024. These records have only recently been linked to the occupation of the decedent, yielding data from nearly 13 million decedents across 503 occupations, including 14,000 pilots and 7,000 flight attendants.
A Larger Dataset and Greater Statistical Power
Prior research has shown that aircrew members receive the largest annual effective dose of ionizing radiation of any U.S. workforce, largely due to exposure to cosmic radiation at high altitudes, and that members of the profession are more likely to be diagnosed with certain cancers than the general population. However, past studies have been limited as to whether this translates to higher rates of cancer mortality. The new research addressed this question using a larger dataset and more statistical power than were previously available.
The team applied a common adjustment approach that accounted for several factors other than occupation that may affect mortality, including age at death, sex, race, ethnicity, educational attainment, and marital status. Radiation-related cancers analyzed in the study included breast cancer (搜索), central nervous system cancers (搜索), multiple myeloma (搜索), leukemia (搜索) (except chronic lymphocytic leukemia), lymphoma (搜索), thyroid cancer (搜索), prostate cancer (搜索), melanoma (搜索), and non-melanoma skin cancers (搜索).
A Pattern Consistent with the Radiation Hypothesis
The researchers found that pilots and flight attendants had statistically significantly higher rates of death from breast, central nervous system, and prostate cancers and melanoma (搜索). Pilots also had a higher rate of leukemia (搜索) deaths. In all, about 6.9 percent of deaths among flight attendants and 6.7 percent of deaths among pilots were from radiation-related cancers, according to the analysis. These proportions were higher than for any of the other professions, including nuclear technologists, who are routinely exposed to radiation from non-cosmic sources yet placed 12th on the list, the authors said.
The study's design rested on a simple logic: if cosmic radiation were truly driving cancer among aircrew, the signal should appear specifically in cancers that radiation is known to cause, and should not appear in cancers such as colon cancer that are not caused by this type of radiation. The pattern was consistent with this expectation. For cancers unrelated to radiation, aircrew sat near the middle of the pack, while nuclear technologists ranked near the top and ground-based aviation workers did not show elevated rates.
"That internal consistency—seeing the types of cancers we expected in the workers we predicted would be most at risk, with control groups behaving precisely as expected—makes it unlikely that the pattern arose by chance," the authors wrote.
Exposure Levels and Regulatory Gaps
Aircrew accrue an estimated 3 to 6 millisieverts per year of cosmic radiation, depending on flight paths—an order of magnitude above the estimated 0.4 millisieverts received annually by an average air traveler taking 10 cross-country round-trip flights per year, according to the CDC. The Federal Aviation Administration formally recognizes pilots and flight attendants as occupationally exposed to ionizing radiation, but unlike other radiation-exposed workers or aircrew in other countries, U.S. aircrew are not subject to federal dose limits or monitoring requirements.
Study Limitations and Implications for Travelers
The authors acknowledged that the study, by itself, is not iron-clad proof of cause and effect. The data cannot measure how much radiation any individual actually received, occupations are sometimes recorded incorrectly on death certificates, and people at higher baseline risk for certain cancers may be more likely to work as pilots or flight attendants. Aircrew also face other hazards, from disrupted circadian rhythms to in-cabin exposures, that could not be fully accounted for.
Importantly, the study does not indicate that occasional flying meaningfully raises cancer risk. The detected signal generally reflects an entire career spent in the skies. A traveler who takes 10 cross-country round-trip flights a year absorbs only about 0.4 millisieverts—roughly a seventh to 1/15 of what an aircrew member accrues in a single year, and only over a few years of heavy travel rather than an entire working life.