Pilots and Flight Attendants Face a Real Cancer Risk. Frequent Flyers Shouldn’t Panic

The approach rested on simple logic. If cosmic radiation were truly driving cancer among air crew, the signal should appear specifically in the cancers that radiation is known to cause (breast, prostate, melanoma, and certain leukemias), and the signal should not appear in cancers like colon cancer that aren’t caused by this type of radiation. We would also expect to see higher rates of radiation-associated cancers among other types of workers exposed to radiation, like nuclear technologists. Meanwhile, unless something about aviation other than flying was associated with these cancers, we wouldn’t expect to see higher rates in aviation workers who remain on the ground, like aircraft mechanics and assemblers.

The pattern was hard to miss. Among all 503 occupations, flight attendants and pilots had the highest and second-highest share of deaths from radiation-related cancers—6.9% and 6.7%, respectively, after accounting for differences in age, sex, and other factors—a proportion that exceeded that of nuclear technologists. For cancers unrelated to radiation, aircrew sat near the middle of the pack. And our comparison groups fell exactly where the radiation hypothesis predicted; nuclear technologists ranked near the top, while ground-based aviation workers did not.