Ultraviolet light exposure suppresses the immune system. So melanoma incidence increases even in non-sun exposed areas.
Immunosuppression induced by ultraviolet radiation: relevance to public healthBy THE ASSOCIATED PRESS
Published: July 28, 2009
Filed at 9:46 p.m. ET
LONDON (AP) -- International cancer experts have moved tanning beds and other sources of ultraviolet radiation into the top cancer risk category, deeming them as deadly as arsenic and mustard gas. For years, scientists have described tanning beds and ultraviolet radiation as ''probable carcinogens.''
A new analysis of about 20 studies concludes the risk of skin cancer jumps by 75 percent when people start using tanning beds before age 30. Experts also found that all types of ultraviolet radiation caused worrying mutations in mice, proof the radiation is carcinogenic. Previously, only one type of ultraviolet radiation was thought to be lethal.
The new classification means tanning beds and other sources of ultraviolet radiation are definite causes of cancer, alongside tobacco, the hepatitis B virus and chimney sweeping, among others.
Previous studies found younger people who regularly use tanning beds are eight times more likely to get melanoma than people who have never used them. In the past, WHO warned people younger than 18 to stay away from tanning beds.
Study: Tanning Beds as Deadly as Arsenic