Aircrew and the Hidden Radiation Risk of Flying: What New Research Reveals

For most passengers, flying is associated with holidays, business trips and long journeys across continents. For pilots and cabin crew, however, spending thousands of hours in the sky may involve a less visible occupational exposure: cosmic radiation.

A new study examining mortality data from almost 13 million people across more than 500 occupations has highlighted concerns about radiation exposure among airline workers. The research suggests that pilots and flight attendants experienced the highest proportions of deaths from certain radiation-related cancers among the occupations examined.

The findings, published in JAMA Internal Medicine, have renewed calls for stronger occupational protections for aircrew and closer monitoring of the risks associated with long-term exposure to cosmic radiation.

Why are aircrew exposed to cosmic radiation?

Radiation is present naturally in the environment, including high-energy particles that originate from space. Earth's atmosphere provides significant protection from this cosmic radiation, but that protection decreases as altitude increases.

Commercial aircraft typically operate at altitudes where passengers and crew receive greater exposure to cosmic radiation than people at ground level. The amount can vary according to factors including flight altitude, duration and route.

According to the study, US aircrew members receive an estimated 3 to 6 millisieverts of cosmic radiation annually. By comparison, the researchers estimated that an average traveller taking 10 cross-country return flights a year receives around 0.4 millisieverts.

The difference is largely explained by frequency. A passenger may fly a handful of times each year, whereas professional aircrew can spend hundreds of hours in the aircraft environment.

What did the researchers discover?

Researchers analysed US death certificate data covering the period from 2020 to 2024. The dataset included occupational information that had only recently been linked to mortality records.

In total, the analysis covered nearly 13 million deaths involving people from 503 occupations. Among those included were approximately 14,000 pilots and 7,000 flight attendants.

The researchers considered several factors that can influence mortality, including age, sex, race, ethnicity, educational attainment and marital status.

They examined deaths involving several cancers that can be associated with radiation exposure. These included breast cancer, cancers affecting the nervous system, leukaemia, lymphoma, thyroid cancer, prostate cancer and skin cancer.

The analysis found statistically significant increases in mortality from breast cancer, central nervous system cancers, prostate cancer and melanoma among pilots and flight attendants. Pilots also showed a higher rate of death from leukaemia.

One of the study's notable findings was that nearly 7 per cent of deaths among pilots and flight attendants were attributed to radiation-related cancers. The researchers said this proportion was higher than that observed among the other occupational groups included in their analysis, including nuclear technologists.

Does this mean flying causes cancer?

Not necessarily.

The study identifies an association between aircrew occupations and cancer mortality. It does not establish that cosmic radiation was directly responsible for individual cancer cases or prove that flying caused those deaths.

This distinction is important because occupational health research can involve many potential confounding factors. Aircrew members may have different sleep patterns, working schedules, reproductive histories, lifestyle factors and other occupational exposures compared with people working on the ground.

The researchers themselves highlighted limitations in the analysis. Occupations recorded on death certificates may sometimes be incorrectly classified, while the available data did not provide detailed information about the precise radiation exposure experienced by each individual.

As a result, the findings should be interpreted as evidence of a potential occupational health concern rather than proof of a direct cause-and-effect relationship.

Why might pilots and cabin crew face different risks?

The most obvious factor is repeated exposure.

A long-haul pilot or flight attendant may spend a substantial portion of their working life at cruising altitude. Over years or decades, relatively small exposures accumulated across thousands of hours could become more significant.

Cosmic radiation also varies depending on flight conditions. Higher altitudes generally provide less atmospheric shielding, while routes at higher latitudes can experience greater exposure because of differences in Earth's magnetic protection.

This means that radiation exposure is not necessarily identical for every member of an airline workforce.

What could stronger protection look like?

The researchers argue that occupational radiation protections for aircrew should reflect the levels of exposure they experience.

That could involve better systems for estimating individual cumulative exposure, improved occupational monitoring and clearer guidance for workers and employers.

Airlines could also consider radiation exposure when planning crew schedules and routes, particularly for workers who regularly operate long-haul or high-altitude services.

The goal would not necessarily be to prevent people from flying. Instead, better measurement could help employers understand which workers receive the greatest cumulative exposure and support evidence-based occupational health measures.

What does the research mean for passengers?

For the occasional traveller, the findings are unlikely to mean that ordinary air travel should be viewed as a major cancer risk.

The researchers' estimates show a substantial difference between the exposure experienced by professional aircrew and that of typical passengers. Someone who flies occasionally spends far less time at altitude than someone whose career involves flying every week.

Frequent flyers may receive more exposure than occasional travellers, but the occupational situation of pilots and cabin crew is fundamentally different because of the cumulative number of hours spent at altitude throughout a career.

The study is therefore primarily relevant to occupational health rather than routine holiday travel.

A growing occupational health question

The latest research adds to previous studies suggesting that aircrew may experience higher rates of certain cancers than the general population. What makes this analysis notable is its focus on mortality across a very large number of occupational groups.

The researchers said the pattern observed among pilots and flight attendants was not seen in the same way for non-radiation-related cancers or among ground-based aviation workers. They concluded that the findings support an association between cumulative in-flight cosmic radiation exposure and several radiation-related cancers.

However, more research will be needed to establish the precise relationship between exposure and cancer outcomes.

Future studies could benefit from detailed occupational histories, individual flight records and more accurate estimates of cumulative radiation exposure. Such information could help researchers distinguish the effects of cosmic radiation from other factors associated with working in aviation.

What happens next?

The central issue is not whether people should stop flying. Aviation remains one of the world's most important forms of transport, connecting countries and communities every day.

Instead, the research raises a question about how occupational health protections should evolve as scientists learn more about the long-term effects of working at altitude.

Pilots and cabin crew spend far more time exposed to cosmic radiation than ordinary passengers. The new findings suggest that this difference deserves closer attention, particularly for workers who accumulate thousands of flight hours over their careers.

The study does not prove that cosmic radiation caused the cancers recorded among aircrew members. It does, however, provide further evidence of an association that researchers believe warrants greater occupational monitoring and protection.

For airline workers, the message is therefore one of awareness rather than alarm. Better exposure measurement, continued medical research and appropriate workplace safeguards could help determine how aviation employers should manage this unusual but potentially important occupational hazard.

Source: The Independent, reporting on research published in JAMA Internal Medicine, 18 August 2026.