The Canadian Press Tanning beds, which bathe users in ultraviolet light, increase the risk of basal cell and squamous cell carcinoma, a new U.S. study suggests, especially for those under the age of 30.

A new U.S. study suggests people who use tanning beds face an increased risk of developing two common types of skin cancer, basal cell and squamous cell carcinoma.

The devices, which bathe users in ultraviolet A and B rays, have been tentatively linked to a more deadly form of skin cancer called melanoma. Until now, however, researchers had not looked at artificial tanning and more common types of cancer.

The danger appears to be particularly high for people under 30 years of age, says the study, published today in the Journal of the National Cancer Institute.

"Tanning lamps mimic sunlight and provide such an intense, concentrated dose of [ultraviolet rays], we would predict that people who use these devices may get skin cancers," says epidemiologist Margaret Karagas, an associate professor of community and family medicine at Dartmouth Medical School in Hanover, N.H.

"Also, tanning lamp users often get a burn like a sunburn, and sunburns are linked to the risk of all three skin cancers: basal cell, squamous cell and melanoma."

In the study, the researchers looked at 603 people newly diagnosed with basal cell carcinoma, 293 diagnosed with squamous cell carcinoma, and 540 people with no cancer. The scientists queried the participants, aged 25 to 74, about their tanning lamp use, history of sun exposure, tendency of sunburn, any radiation treatments and smoking history.

Overall, those who used tanning devices were 2.5 times more likely to get squamous cell carcinoma and 1.5 times more likely to get basal cell carcinoma than people who did not use the lamps. Other factors did not seem to explain the cancer, the researchers said.

Tanning beds were used most frequently by women younger than 50 years.

The risk of basal cell carcinoma rose 20% for each decade younger the participants were when they began using tanning beds. Likewise, the risk of squamous cell carcinoma rose 10% for each decade earlier the use began. Dr. Karagas says this is not surprising.

"Sun exposure early in life also appears to play an important role in risk of skin cancer," she says.

This has caused worry among health authorities, since sun-lamp tanning is a popular activity among teens. One study of high school-age girls found more than 50% of girls had used a commercial tanning bed at least four times in the past year.

For this reason, some health authorities have suggested that minors should be restricted from artificial tanning or obtain written consent from parents to do so.

Dr. Barbara Wylie, director of cancer control policy with the Canadian Cancer Society said she was pleased to see more evidence of the harmful impact of tanning lamps.

"You can't assume that tanning salons are going to give you a safe tan," she said. "We certainly do not recommend that anybody use them."

Dr. Wylie said the society would call on Health Canada and other levels of government to look at the potential health risks of the salons when setting regulations.