Blog | Friday, September 5, 2014

QD: News Every Day--Flight crews may have twice the rate of melanoma

Pilots and cabin crew have approximately twice the incidence of melanoma compared with the general population, a meta-analysis found.

Researchers conducted the review of 19 studies with more than 266,000 participants. Results appeared online Sept. 3 in JAMA Dermatology.

The overall standardized incidence ratio of participants in any flight-based occupation was 2.21 (95% CI, 1.76 to 2.77; P<0.001); for pilots was 2.22 (95% CI, 1.67 to 2.93; P=0.001); and for cabin crew was 2.09 (95% CI, 1.67 to 2.62; P=0.45).

The overall summary standardized mortality ratio of participants in any flight-based occupation was 1.42 (95% CI, 0.89 to 2.26; P=0.002); for pilots was 1.83 (95% CI, 1.27 to 2.63, P=0.33); and for cabin crew was 0.90 (95% CI, 0.80 to 1.01; P=0.97).

Researchers noted that the amount of cosmic radiation to which airline crews are exposed has always found to be consistently below the allowed dose limit of 20 mSv per year. And, the amount of ultraviolet-B radiation that penetrated glass and plastic airplane windshields was less than 1%. On the other hand, ultraviolet-A radiation, the kind that damages DNA, varied significantly depending on windshield material, with very little coming through plastic and 54% coming through glasses.

The authors wrote, “Windshields and cabin windows of airplanes seem to minimally block UVA radiation, and it is known that, for every additional 900 meters of altitude above sea level, there is a 15% increase in intensity of UV radiation. At 9,000 meters, where most commercial aircraft fly, the UV level is approximately twice that of the ground. Moreover, these levels are even higher when flying over thick cloud layers and snow fields, which could reflect up to 85% of UV radiation.”