Pilots May Face Greater Cancer Risk

Dec. 12 -- THURSDAY, Dec. 11 (HealthDay News) -- Highly experienced pilots may be at risk of DNA damage from prolonged exposure to cosmic ionizing radiation, according to a study that compared 83 airline pilots to 50 university faculty members from the same U.S. city.

Blood samples from the participants were analyzed for DNA abnormalities, specifically the number of times pairs of chromosomes had changed places -- called translocations. Since translocations aren't eliminated from the blood like other forms of chromosomal abnormalities, they serve as a reliable indicator of cumulative DNA damage associated with radiation exposure, according to the study authors.

The researchers found that pilots had a higher average frequency of translocation than the university faculty members -- 0.39 per 100 cell equivalents vs. 0.32 per 100 cell equivalents. However, after the researchers adjusted for age, smoking and other risk factors for DNA damage, there was no difference between the two groups.

But, differences did emerge when the researchers focused on how long the pilots had been flying. Those who'd flown the most had twice the frequency of translocations as those who'd flown the least.

The findings suggest that experienced pilots may be exposed to biologically significant doses of ionizing radiation, said the researchers, who noted that chromosomal abnormalities have been linked with an increased risk of cancer.

The study was published in the Dec. 11 online issue of Occupational and Environmental Medicine.

More information

The U.S. Environmental Protection Agency has more about ionizing and non-ionizing radiation.

SOURCE: BMJ Specialist Journals, news release, Dec. 11. 2008