WASHINGTON: Airline pilots and flight attendants may face higher mortality from certain radiation-associated cancers compared with workers in many other occupations, according to a large US study published in JAMA Internal Medicine.
Researchers examined around 13 million US death certificates from 2020 to 2024 through the National Vital Statistics System. The analysis included approximately 14,000 pilots and 7,000 flight attendants whose deaths were recorded during the study period.
The researchers focused on cancer types that can be associated with exposure to ionizing radiation, including cosmic radiation encountered during high-altitude flight.
Cosmic Radiation a Key Occupational Exposure
Airline crews spend significantly more time at high altitudes than most people, where the atmosphere provides less protection from cosmic radiation originating from space and the sun.
According to the information presented in the study, airline crew members can receive an estimated 3 to 6 millisieverts (mSv) or more of cosmic radiation exposure per year, depending on factors such as flight routes, altitude and time spent in the air.
By comparison, a passenger taking 10 cross-country round trips in a year could receive roughly 0.4 mSv from cosmic radiation.
This means frequent-flying crew members can accumulate substantially more occupational radiation exposure than occasional passengers.
Risk May Increase With Years of Employment
The researchers noted that occupational exposure is cumulative, meaning the amount of radiation received over a person’s career can increase with the number of years spent working as a pilot or flight attendant.
Lead researcher Anupam B. Jena, MD, PhD, and his colleagues examined mortality patterns to determine whether airline workers showed unusual rates of death from cancers associated with radiation exposure.
However, the findings should not be interpreted as proving that cosmic radiation directly caused individual deaths.
Cancer Patterns Among Flight Attendants
Among flight attendants, 6.9% of recorded deaths in the study were attributed to radiation-associated cancers.
Researchers observed statistically elevated mortality patterns involving several cancers, including:
- Melanoma
- Central nervous system (CNS) cancers
- Breast cancer
- Prostate cancer
The findings indicate that certain cancer mortality patterns among flight attendants differed from expected background levels.
Cancer Risk Observed Among Pilots
For pilots, radiation-associated cancers accounted for approximately 6.7% of total deaths examined in the study.
Researchers identified elevated mortality involving several cancer categories, including:
- Central nervous system cancers
- Leukemia
- Melanoma
- Breast cancer
- Prostate cancer
The results add to previous concerns about occupational health risks faced by aviation professionals who spend substantial amounts of time at cruising altitude.
Lung Cancer Excluded From Analysis
The researchers did not include lung cancer in their radiation-associated cancer analysis because smoking could significantly influence lung cancer mortality.
Excluding lung cancer allowed researchers to reduce the potential impact of smoking when examining cancer patterns potentially linked to occupational radiation exposure.
This distinction is important because cancer risk among airline workers can be influenced by multiple factors, and cosmic radiation is only one potential occupational or environmental exposure.
What the Findings Mean for Airline Crews
The study highlights the importance of continued monitoring of occupational radiation exposure among pilots and flight attendants.
Airline crews generally spend much more time exposed to cosmic radiation than ordinary passengers, particularly those who regularly operate long-haul or high-altitude flights.
The amount of exposure can vary depending on flight altitude, latitude, route and solar activity. Longer careers can also result in greater cumulative exposure.
The findings do not mean that every pilot or flight attendant will develop radiation-related cancer. Rather, they point to differences in mortality patterns that warrant further research into the long-term health effects of occupational cosmic radiation.
