Airline pilots can be exposed to the same amount of UV-A radiation as if they visited a tanning bed, because airplane windshields do not completely block UV-A radiation.
Airplane windshields are commonly made of polycarbonate plastic or multilayer composite glass. UV-A radiation can cause DNA damage in cells and its role in melanoma is well known, according to the background information in an article by Martina Sanlorenzo, M.D., of the University of California, San Francisco, and co-authors. It may be why airline crews have 2X the incidence of melanoma as the general population.
They measured the amount of UV radiation in airplane cockpits during flights and compared them with measurements taken in tanning beds. The cockpit radiation was measured in the pilot seat of a general aviation turboprop airplane through the acrylic plastic windshield at ground level and at various heights above sea level.
Sun exposures were measured in San Jose and Las Vegas around midday in April.
The findings show pilots flying for 56.6 minutes at 30,000 feet get the same amount of radiation as that from a 20-minute tanning bed session. The authors suggest the levels could be higher when pilots are flying over thick clouds and snow fields, which can reflect UV radiation.
"Airplane windshields do not completely block UV-A radiation and therefore are not enough to protect pilots. UV-A transmission inside airplanes can play a role in pilots' increased risk of melanoma. ... We strongly recommend the use of sunscreens and periodical skin checks for pilots and cabin crew," the authors conclude.
Source: The JAMA Network Journals