Pilots, aircrew face higher radiation-related cancer death rates, study

Radiation-related cancer deaths more common in aircrew than other occupations, study In short: A new study found almost 7 per cent of all deaths among US flight attendants and pilots from 2020-2024 were due to radiation-related cancer, the highest rate among the 500 occupations studied. The researchers suggested increased mortality could be caused by cosmic radiation, which aircrews are exposed to at higher levels. What's next? The Transport Workers' Union and experts have called for better protections for workers but the Australian Radiation Protection and Nuclear Safety Agency says the results are not clear cut. A large US study has found that of 500 occupations, flight attendants and pilots had the highest proportion of radiation-related cancer deaths. The study, published in JAMA Internal Medicine, looked at almost 13 million US death records from 2020–2024. The researchers found that radiation-related cancers (such as leukaemia, breast, thyroid and skin cancers) were listed on 6.9 per cent of deaths among flight attendants and 6.7 per cent of deaths among pilots. This was the highest and second-highest proportions of radiation-related cancer deaths across all occupation groups in the US. In comparison, ground crews, which work in a similar environment to aircrew but without the air travel, did not have the same elevated proportion of radiation-related cancer deaths as the pilots and flight attendants. "These findings support consideration of occupational radiation protections for aircrew members commensurate with their exposure level," the researchers concluded. While the research was based on US data, it might be applicable to air crews around the world, said Catherine Olsen, an epidemiologist and melanoma researcher at QIMR Berghofer who was not involved with the study. Exposure to cosmic rays Flight crews spend much longer in the air than the average frequent flyer, and are more exposed to cosmic radiation — high energy particles from the Sun and other cosmic sources. Exposure to too much cosmic radiation can damage our DNA, cause radiation sickness and increase the risk of some cancers. On the ground, we are well protected from cosmic radiation. Australians on average receive 3.4 millisieverts a year from all types of ionising radiation. But the thinner atmosphere at higher elevations where airplanes fly lets more radiation sneak through. Aircrews are among the most exposed groups of workers to ionising radiation, according to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). It limits aircrew exposure to 20 millisieverts (mSv) per year averaged over five years — about the same as three chest CT scans. The organisation also has a lower "reference level" of 6 mSv per year, that they recommend aircrew and airlines try to maintain. Relationship 'more complex' While it is well known that aircrews are exposed to increased cosmic radiation, linking that to increased cancer mortality is complicated. Dr Olsen said that comparing air crews with other occupations like ground crews and nuclear workers provided more evidence that the cosmic radiation could be causing the increase in radiation-related cancer deaths. "I'm confident that it's a very well conducted study," she said. "A limitation is that there's a possibility that there might be misclassification on death certificates if that occupation is not recorded properly." But an ARPANSA spokesperson said the study did not account for lifestyle factors like 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,"they said. Dr Olsen said if there was an increase risk of death in these occupations, airlines and health care professionals needed to be more aware. "When those flight crew and pilots are having their medical checks, there should be a heightened kind of degree of concern of any symptoms that might be related to cancer." Cancer risk 'not discussed' Ebanie Fletcher, who has worked as an Australian flight attendant for more than 20 years, said radiation risk was not something that was discussed by the airlines. "None of it is really talked about, especially not by our safety regulators or the industry as a whole," she said. Dr Olsen said there were various approaches to managing exposure for flight crews around the world. "In the US, even though they classify pilots and flight crew as being occupationally exposed to this ionising radiation, there's no monitoring of the dose that people are exposed to," she said. "In Europe, it's a little bit more regulated." In Europe, airlines are required to assess crew exposure, plan schedules to factor in cumulative risk, and provide protection for pregnant workers. ARPANSA maintains the Australian National Radiation Dose Register (ANRDR), which records occupational exposure to radiation in industries from uranium mining and some medical facilities. Airline companies can sign up to this registry, but it is voluntary. "Airlines monitor and manage rostering arrangements to ensure aircrew do not exceed the reference level," a spokesperson said. "Our advice is that there is no evidence of an increased health risk from naturally occurring cosmic radiation during flying when exposure is maintained below the 6 mSv per year reference level." Ms Fletcher said she did not believe that individual doses were monitored in the Australian industry, although she noted that airlines did limit flight hours when someone was pregnant. "Apparently it's important to them when we're pregnant not to be exposed to radiation but not for any other purpose," she said. Virgin, one of the Australian airlines the ABC contacted, said that it monitors radiation to the standards in line with ARPANSA guidelines. Transport Workers' Union national secretary Michael Kaine said more needed to be done. "If we're learning that the job of keeping Australians safe in the skies may come with serious health risks, we can't leave workers to deal with those risks as a scatter-gun approach, airline by airline," he said in a statement. "We need an approach that puts workers and passengers at the centre."