Experienced airline pilots may be at risk of DNA damage due to prolonged exposure to cosmic ionising radiation, according to a study.
Scientists behind the study compared the rate of chromosomal (DNA) abnormalities in blood samples taken from 83 airline pilots and 50 university faculty members from the same US city.
The participants in both groups were 35 to 56 years old, males, and light or non-smokers.
These factors were taken into consideration because age and smoking are known risk factors for cumulative DNA damage.
The researchers revealed that about 70 per cent of the pilots they studied had served int eh military, and that they had undertaken significantly more personal air travel than the university staff.
They said that both these factors might have exposed them to more ionising radiation.
The investigators said that they were basically trying to see the number of times pairs of chromosomes had changed places (translocations), a reliable indicator of cumulative DNA damage associated with radiation exposure, expressed as a score per 100 cell equivalents (CE).
The study showed that the average frequency of chromosome translocation was higher among the pilots than the faculty staff, but there was not difference after adjusting for age and other influential factors.
According to the researcher, differences emerged when the analysis focused on how long pilots had been flying.
They said that the chromosome translocation frequency of those who had flown the most was more than twice that of those who had flown the least, after taking age into account.
They revealed that adjusting for the impact of cigarette smoking, personal air travel, and diagnostic x-ray procedures did not affect these findings.
Based on their observations, the researchers came to the conclusion that highly experienced flight pilots might be exposed to "biologically significant doses of ionising radiation."
A research article on the study will be published in the journal Occupational and Environmental Medicine.