Study links flight crews to highest radiation-related cancer mortality

A study by Harvard researchers found that pilots and flight attendants in the United States had the highest share of deaths from radiation-related cancers among 503 occupations, ERR reported. The findings show a correlation rather than a causal relationship.

Flight crews are exposed to more ionising radiation than workers in any other occupation because cosmic radiation is stronger at high altitudes. The exposure can cause cell mutations that may lead to cancer.

The researchers compared 12.7 million deaths recorded in the United States between 2020 and 2024. They focused on radiation-related cancers, including lymphoma and cancers of the breast, thyroid and prostate.

Radiation-related cancers accounted for 6.9 percent of deaths among flight attendants and 6.7 percent among pilots. Nuclear technicians, who work with ground-based sources of radiation, ranked 12th in the comparison.

The analysis found that the higher mortality among flight crews was associated specifically with radiation-related cancers rather than cancer in general. Exposure to chemicals in aviation did not explain the findings: ground-based mechanics and aircraft manufacturers who regularly handle aviation fuel and hydraulic fluids did not show a higher cancer risk.

The researchers said the risk was more likely linked to the interaction between galactic cosmic radiation and the aircraft fuselage. Thickening or lining the fuselage would not necessarily protect workers, because the additional material can generate secondary radiation when high-energy cosmic particles collide with atoms in the aircraft.

The most effective way to reduce exposure would be to plan flight schedules and routes carefully. Radiation doses rise sharply with altitude and latitude, with crews on polar and very long-distance flights receiving the highest doses because Earth’s magnetic field provides less protection there.

Different rules in the European Union

Unlike the European Union, the United States currently has no mandatory dose limits or radiation monitoring requirements for flight crews. In European aviation, measuring workers’ radiation doses and adjusting the schedules of pregnant employees have long been mandatory.

The US Federal Aviation Administration recognises the risk but does not require airlines to take specific measures. The study said existing practices could reduce exposure by limiting crews’ annual flight hours, rotating staff on higher-risk routes, protecting pregnant workers from radiation doses and rerouting flights during strong solar flares.

Ordinary passengers are exposed to far less radiation. Even 10 flights a year would not produce a dose comparable to that received by flight crews.