Commercial airline pilots previously were reported to be at increased risk for some cancers, but studies on the biological effects of cosmic radiation exposure were limited, according to the researchers.

Dr. Vilhjalmur Rafnsson of the University of Iceland and his colleagues conducted a case control study involving 445 men to determine whether employment as a pilot is associated with lens opacification.

Cosmic Radiation

All participants in the study were 50 years or older and other factors that contribute to cataract risk, including smoking, age and sunbathing, were controlled for in the statistical analysis.

Exposure to cosmic radiation was assessed based on employment time as pilots, annual number of hours flown on each aircraft type, time tables, flight profiles and individual cumulative radiation doses calculated by computer.

The odds ratio for nuclear cataract risk among cases and controls was 3.02 for pilots compared with non-pilots, adjusted for age, smoking status and sunbathing habits, the researchers reported.

The study appears in the journal Archives of Ophthalmology.