Indoor tanning now attracts about one million people every day — more than two-thirds of them women and most of them under age 30. Since 1980, while the incidence of many other cancers has leveled off or fallen, melanoma, the deadliest form of skin cancer, has become more common. According to the National Cancer Institute, melanoma rates among white women ages 20 to 49 more than doubled between 1975 and 2007. Many health organizations (including the American Academy of Dermatology Association and the Skin Cancer Foundation) have concluded that tanning salons and indoor tanning devices are linked to the rise in melanoma, and these groups are demanding stricter regulations.
A study at the University of Minnesota — published in the journal Cancer Epidemiology, Biomarkers, and Prevention (June 2010) — offers the strongest case yet for that link. Researchers collected information from 1,167 Minnesotans diagnosed with melanoma between 2004 and 2007 and compared them with 1,101 age- and gender-matched people without melanoma who were drawn from the state list of driver’s license holders. Researchers asked participants when they started indoor tanning, how long and how often they tanned, and what devices they used. They were also asked about burns resulting from indoor tanning and other melanoma risk factors, including family history of the disease.
Overall, indoor tanning was associated with a 74% greater likelihood of developing melanoma. Moreover, the greater the frequency and intensity of exposure, the greater the risk. For example, a person with 50 or more hours of indoor tanning (or more than 100 sessions or 10 or more years) was 2.5 to 3 times more likely to develop melanoma than a person who had never tanned indoors. The risk was even higher for those who used so-called high-intensity or high-pressure devices: they were three to four times more likely to develop melanoma than people who hadn’t tried indoor tanning. (According to the American Cancer Society, high-pressure tanning bulbs can deliver up to 15 times the sun’s ultraviolet radiation.) The researchers conclude that no indoor tanning should be considered safe.
Indoor tanning may actually be riskier than sunbathing. In this study, it was more closely linked to melanoma than either recreational sunbathing or routine sun exposure through outdoor work. That doesn’t mean you should head for the beach instead of the tanning salon; any tanning is a sign of skin damage and may increase your risk for skin cancer.