Cosmic radiation putting pilots and flight attendants at risk of deadly cancers

A study has found that pilots and flight attendants are being exposed to cosmic radiation from outer space more than others, and are at a greater risk of dying from related cancers. Researchers at Harvard Medical School and others compared death certificates of people who had worked in different professions linked to radiation exposure. Their analysis revealed that the risk of cancers linked to radiation was a lot higher for pilots and attendants than even people working directly with such materials, such as nuclear scientists.

The findings were published Monday in JAMA Internal Medicine. The authors said that authorities need to take note of the harmful effects of cosmic rays, and to do more to protect the people who help us travel in the skies. "These findings support consideration of occupational radiation protections for aircrew members commensurate with their exposure levels," they said.

Cosmic rays at higher altitudes have previously been flagged to have a major bearing on the health of pilots and attendants. In the United States, people in these professions have the highest average exposure to ionising radiation, something that has been known to trigger harmful mutations in the body. Lead author Vishal Patel says, it has been difficult to establish whether the radiation means more cancer deaths among the employees in this field of work.

Professions with radiation exposure compared

So the researchers took a different approach. Since 2020, death certificates in the US started linking the deceased to their professions. This allowed the team to compare radiation-related cancer deaths across different fields of work. They also used other comparisons, such as cancers not linked to radiation. They used two professions as a control: nuclear technologists and ground aircrew members. The former is routinely exposed to radiation, while the latter only shares a part of the same conditions.

In total, they analysed 12.7 million deaths between 2020 and 2024 across 503 occupations, including 14,000 pilots and 7,000 flight attendants. They found that pilots (6.7 per cent) and attendants (6.9 per cent) had the greatest share of deaths from radiation-related cancers.

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"The checks held. Aircrew ranked near the middle of all 503 occupations for cancers not thought to be radiation-related—so this isn’t a general excess of cancer deaths; it is specific to radiation-related cancers," Patel said. Further, “nuclear technologists, who are exposed to radiation from entirely different sources, ranked 12th, which is what you’d expect if ionising radiation is doing the work.”

Which routes face highest risk from radiation?

Dose rates, or radiation levels, are higher at high latitudes, where the Earth’s magnetic field offers less deflection. "So polar and ultra-long-haul routes carry the highest doses," the study states. Patel says the US currently sets no dose limits or mandates to monitor the employees.

How to solve problem of cosmic radiation for pilots and attendants?

Shielding the plane itself is not the answer, he claims. "A reasonable first step would be individual dose estimation with records that follow a crew member across employers over a career," Patel said.

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Are passengers at risk from cosmic radiation too?

He clarified that even the most frequent flier is nowhere close to the levels of radiation exposure as pilots and attendants.