There is a particular unease that comes from seeing that an ordinary part of life has been linked to cancer. If you fly a few times a year, the results of a new study by two of us may elicit exactly that feeling; pilots and flight attendants die of radiation-related cancers at higher rates than workers in over 500 occupations that we studied. So should you rethink your travel plans?
We aren’t, and we don’t think you should, either. Understanding why can teach us a lot about how to read health headlines like this one. Commercial jets cruise at altitudes above 30,000 feet, where the atmosphere is thin, allowing for higher speeds and engine efficiency.
But the thinner atmosphere offers less shielding from cosmic radiation (in the form of high-energy particles that stream in from the sun and from deep space) than we enjoy closer to sea level. Spending hundreds of hours among the clouds each year, air crew absorb more radiation, on average, than workers in any other job in the U.S.—including those generating nuclear power and our colleagues who work with radiation for medical purposes. This type of ionizing radiation, in sufficient doses, can damage DNA and give rise to cancer.
What has never been clear is whether the amount aircrew accumulate over a career is enough to increase cancer risk above other occupations. In a new study published in JAMA Internal Medicine, we set out to find that mark. Using federal data on nearly every death in the U.S., newly linked to each person’s usual occupation, we examined more than 12.7 million deaths from 2020 to 2024 (a majority of deaths among adults) across 503 occupations—an approach that earlier studies, which had mortality data on air crew but no other occupations, could not take.
The approach rested on simple logic. If cosmic radiation were truly driving cancer among air crew, the signal should appear specifically in the cancers that radiation is known to cause (breast, prostate, melanoma, and certain leukemias), and the signal should not appear in cancers like colon cancer that aren’t caused by this type of radiation. We would also expect to see higher rates of radiation-associated cancers among other types of workers exposed to radiation, like nuclear technologists.
Meanwhile, unless something about aviation other than flying was associated with these cancers, we wouldn’t expect to see higher rates in aviation workers who remain on the ground, like aircraft mechanics and assemblers. The pattern was hard to miss. Among all 503 occupations, flight attendants and pilots had the highest and second-highest share of deaths from radiation-related cancers—6.9% and 6.7%, respectively, after accounting for differences in age, sex, and other factors—a proportion that exceeded that of nuclear technologists.
Extract — continue reading at the source.
