At 30,000 feet: What pilots and cabin crew should know about cancer risk

Commercial flights typically reach altitudes over 30,000 feet, providing less atmospheric shielding against cosmic radiation from space. While individual flights pose minimal radiation risk to passengers, pilots and cabin crew who spend extensive time in the air over years may accumulate higher exposure. A recent study published in JAMA Internal Medicine revealed that pilots and flight attendants experience a higher proportion of radiation-related cancer deaths compared to workers in other occupations.

Six-point-nine percent of flight attendants and six-point-seven percent of pilots died from radiation-associated cancers, versus five percent among the general workforce. However, the study indicates an association, not causation, and other factors like disrupted sleep patterns may also contribute. Dr Amit Upadhyay, a hematologist and oncologist, explained that thinner atmospheric layers at cruising altitude expose aircrew to more cosmic ionizing radiation.

While his single flight exposure is low, cumulative exposure over decades can elevate the risk of DNA damage and cancer development. The National Academies' 2026 report highlights that radiation exposure for aircrew depends on altitude, latitude, flight duration, and solar activity, with doses compounding over a career. Relevant cancers include leukaemia, lymphoma, multiple myeloma, melanoma, breast, thyroid, and central nervous system cancers.

Dr Upadhyay cautioned against solely attributing these cancers to cosmic radiation, noting that aircrew may also face disrupted circadian rhythms from crossing time zones and working at night. The CDC also acknowledges the potential role of these factors in cancer risk. Experts emphasize that while frequent flyers may receive around 0.4 mSv of cosmic radiation per year, professionals in the industry face much higher exposure, around 3–6 mSv depending on routes.

To mitigate risks, airlines and regulators should monitor cumulative radiation exposure, especially for long-haul, high-latitude routes. Implementing operational measures to minimize unnecessary exposure and ensuring routine medical examinations and cancer screening can aid in long-term risk management.