Flying thousands of feet in the air, closer to the sun, and whilst not facing the same threat that Icarus once did when he flew too close to the sun, there is a danger of sun damage to the skin of pilots, as new research published online by JAMA Dermatology says that airplane windshields do not completely block the harmful rays.
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 scientist from the University of California, San Francisco.
"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," say the authors.
The study states that recently, a meta-analysis reported an increased incidence of melanoma in pilots and cabin crew, which was possibly due to occupational exposures.
While cabin crews’ exposure to cosmic radiation has been assessed in different studies and always found below the allowed dose limit, the cumulative exposure of pilots and cabin crew to UV radiation, a known risk factor for melanoma, has not been assessed to the authors’ knowledge.
One of those involved in the research was Martina Sanlorenzo, M.D., of the University, and along with her colleagues she 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, California, and in 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.
Martina Sanlorenzo, MD et al. The Risk of Melanoma in Airline Pilots and Cabin Crew. JAMA Dermatology, December 2014 DOI:10.1001/jamadermatol.2014.4643