Tanning beds carcinogens, study finds

LONDON — International cancer experts have moved tanning beds and ultraviolet radiation into the top cancer risk category, deeming both to be definite causes of cancer.

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 ultraviolet radiation are definite causes of cancer, alongside tobacco, the hepatitis B virus and chimney sweeping, among others.

The research was published online in the medical journal Lancet Oncology on Wednesday by experts at the International Agency for Research on Cancer in Lyon, the cancer arm of the World Health Organization.

"People need to be reminded of the risks of sunbeds," said Vincent Cogliano, one of the cancer researchers. "We hope the prevailing culture will change so teens don't think they need to use sunbeds to get a tan."

Cogliano said the classification means experts are confident that tanning beds cause cancer, but he noted they may not be as potent as other carcinogens such as tobacco or arsenic.

Most lights used in tanning beds give off mainly ultraviolet radiation, which causes skin and eye cancer. As use of tanning beds has increased among people under 30, doctors have seen a parallel rise in the numbers of young people with skin cancer, though most types of skin cancer are benign.

According to the studies reviewed by Cogliano and colleagues, using tanning beds caused about a 20 percent increased relative risk of developing melanoma, the deadliest kind of skin cancer.

Cogliano said it was impossible to know how many benign skin cancers might be caused by tanning beds, because of complicating factors like exposure to regular sunlight. He and colleagues examined data from more than 7,000 melanoma cases and found a strong association between tanning bed use and the disease. He compared the link to that found between tobacco and lung cancer.

In Britain, melanoma is now the leading cancer diagnosed in women in their 20s.