A study published in JAMA Internal Medicine examined almost 13 million US death records from 2020 to 2024 and compared radiation-related cancer deaths across 500 occupation groups. Radiation-related cancers, including leukaemia, breast, thyroid and skin cancers, were listed on 6.9 per cent of death records for flight attendants and 6.7 per cent for pilots, the highest and second-highest proportions of any occupation in the United States.
Ground crews, who work in a similar environment to aircrew but without the air travel, did not show the same elevated proportions, the researchers found. They concluded the findings "support consideration of occupational radiation protections for aircrew members commensurate with their exposure level."
Flight crews are among the most exposed groups of workers to ionising radiation, according to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). The agency limits aircrew exposure to 20 millisieverts (mSv) per year averaged over five years, about the same as three chest CT scans, and recommends a lower reference level of 6 mSv per year.
Catherine Olsen, an epidemiologist and melanoma researcher at QIMR Berghofer who was not involved in the study, said the results might apply to aircrews around the world. "I'm confident that it's a very well conducted study," she said, though she noted death certificates could misclassify occupations.
An ARPANSA spokesperson said the study did not account for lifestyle factors such as alcohol consumption, circadian rhythm disruption and lack of sun protection, which can also increase the risk of radiation-related cancers. "The relationship between cosmic radiation exposure and melanoma risk may be more complex than implied by the study," the spokesperson said.