“We performed UV measurement at the pilot seats inside a general aviation plane,” measuring the cosmic radiation coming through the windshield, said Dr. Martina Sanlorenzo who coauthored the new research letter
Sanlorenzo, of the dermatology department at Mount Zion Cancer Research Center at the University of California, San Francisco, and her team recently published an analysis of past research concluding that pilots and cabin crew have approximately twice the incidence of melanoma compared to the general population (see Reuters Health article of September 14, 2014 here: reut.rs/1qtoT5a)
“Our meta-analysis showed an increased risk of melanoma in cabin crew too,” including flight attendants, Sanlorenzo said. “However, the role of UV radiation in melanoma risk could be more important for pilots, who are seated in the cockpits for most of the time, and therefore have a greater exposure
For the new study, the researchers placed UV index meters in the plane pilots seat of a small turboprop light business and utility airplane with six passenger seats and a plastic windshield
They took radiation measurements at ground level and at regular altitude increments in flight, and took readings in two locations, San Jose, California and Las Vegas, Nevada
Then they took the same UV measurements inside a tanning bed
According to their measurements, published in JAMA Dermatology, the aircraft windshield blocked UV-B but not UV-A radiation
UV-A is the most abundant source of solar radiation at the earth’s surface and penetrates beyond the top layer of human skin, increasing the risk for skin cancer, according to the Centers for Disease Control and Prevention. UV-B can cause some forms of skin cancer as well, but does not penetrate the skin as deeply
The researchers calculated that 56 minutes in the pilot’s seat of the plane at 30,000 feet resulted in the same carcinogenic-effective dose of UV-A radiation as a 20-minute tanning session
“Pilots and cabin crew should be aware of the higher risk of melanoma,” Sanlorenzo said. “They should know that windshields are not enough to protect their work environment from UV radiation
Aircraft windshields should be improved to block more UV-A radiation, she said
“We strongly recommend the use of sunscreens and periodical skin check examinations for pilots and cabin crew,” she added
There is great variation in how much radiation exposure pilots will have, depending on altitude, latitude, cloud cover, time of year and other factors, said Hajo Zeeb, head of the prevention and evaluation department at Leibniz Institute for Prevention Research and Epidemiology in Bremen, Germany
Zeeb, who was not involved in the new research, has studied flight crew radiation exposure in the past
There is less exposure in the passenger area of the plane and no exposure at night, he said
“This is one small study, and I guess more will follow to see how different window types allow UV-A transmission, and what would be the best ways to also block UV-A more efficiently,” Zeeb told Reuters Health by email. “Pilots should be made aware of the increased melanoma risk in their professional group, but the link to UV-A transmitted through windows is far from clear as it currently stands
