Abstract and Introduction
Every year, millions of people climb in various states of undress into warm, glowing tanning beds, where during a typical 2- to 15-minute session they'll absorb a controlled dose of ultraviolet (UV) radiation at an intensity up to two to three times stronger than the sunlight striking the equator at noon. The tanning industry has grown rapidly since the 1980s, rising to an estimated 28 million users in the United States. This rise has been accompanied by an increase in diagnoses of skin cancer.
The reasons behind the rising skin cancer diagnoses remain open to debate. Some experts attribute the rise to more frequent skin cancer screening, whereas others blame environmental and behavioral risk factors, particularly changes in UV exposure. In this latter context, UV-emitting tanning beds—classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC) —have come under growing scrutiny.
People tan to look healthy, but looks can be deceiving; UV radiation causes all three types of skin cancer. Melanoma, a tumor of the cells that produce the skin pigment melanin, is the rarest but deadliest type, accounting for 75% of skin cancer deaths worldwide. According to the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program, melanoma incidence among U.S. whites (who develop the disease more often than other races) rose from 8.7 cases per 100,000 people in 1975 to 28 cases per 100,000 in 2009. Most of that increase occurred in older men, who rarely tan indoors. But a closer look at the age-stratified SEER data reveals that melanoma rates among white girls and women aged 15–39 rose by 3.6% per year between 1992 and 2006, compared with a 2% increase per year among boys and men of the same ages.
Although they're not tracked by SEER, squamous cell carcinoma (SCC) and basal cell carcinoma (BCC)—the other two types of skin cancer—also appear to be on the rise, according to regional studies from the United States and Europe. A recent study by Anne Marie Skellett, a consulting dermatologist at Norfolk and Norwich University Hospital, reveals that BCC diagnoses among people under age 30 in the United Kingdom jumped 145% between 1981 and 2006.
Statistics such as these have prompted 33 U.S. states and some municipalities to ban or restrict indoor tanning among children under age 18. California's ban, signed into law in October 2011, was the first, followed by Vermont in April 2012 and the city of Chicago the following June. Other states have introduced legislation to limit indoor tanning among minors.
Mary Brady, an associate professor of surgery at Weill Medical College in New York and the author of an editorial on indoor tanning that appeared in the May 2012 issue of the Journal of Clinical Oncology, says the bans make sense. "We legislate against smoking in kids less than 18, and that sends a strong message that there's something wrong with it," she says. "We need to send the same message on indoor tanning."
But the bans have drawn a backlash from the tanning bed industry, whose representatives say they've been unfairly and incorrectly singled out. John Overstreet, executive director at the Indoor Tanning Association in Washington, DC, describes the evidence linking indoor tanning to skin cancer as speculation and advocacy science reported by the media as fact. He points out that UV light triggers skin cells to produce vitamin D, which may have cancer-protective effects. "It's frustrating," he says. "There's no doubt that repeated overexposure to UV or burning can cause skin problems, but you also have to look at the health benefits, and that issue always gets lost."