Part of the concern among medical organizations is that of the 30 million Americans who frequent tanning salons, nearly 2.3 million are teenagers - one of the groups most vulnerable to developing skin cancers, according to the AADA.

According to the July 2009 report from the International Agency for Research on Cancer (IARC), part of the World Health Organization, indoor tanning use by those under 35 is correlated with a 75 percent increase in rates of melanoma. In the report, the IARC also shifted indoor tanning into its highest-risk category - "carcinogenic to humans."

Basing their conclusions on around 19 studies conducted over a period of 25 years, the IARC recommended banning indoor tanning for children under 18 years of age, which the AADA also supports. In addition to the link between youth exposure to indoor tanning and skin cancers, the groups also claim to have found an association between ultraviolet-emitting tanning beds and eye cancer.

Other studies finding a link between tanning beds and skin cancer are a Swedish paper from 1994 that showed young women who used tanning parlors ten times a year had seven times the risk for developing melanoma, and a 2002 Dartmouth study that showed tanning bed users had an increased risk for getting other forms of skin cancer. According to the study, they were 2.5 times more likely to get squamous cell carcinoma, and 1.5 times more likely to develop basal cell carcinoma.

Nonetheless, critics feel there are methodological flaws in the studies cited by the IARC. An FDA epidemiologist who reviewed the IARC study for the federal agency said possible limitations included people inaccurately remembering their tanning history and the difficulty in separating outdoor and indoor UV ray exposure when determining cancer risk.

And in a report posted to the FDA's website on Tuesday, the agency noted that due to a "paucity of studies" the IARC report was not able to establish a dose-response relationship, an important tool for determining real cancer risk. Most troubling, they observed that for melanoma, only four of the 19 studies examined by the IARC were statistically significant in suggesting a greater risk for those who used tanning salons at least once as opposed to those who never used them.

Still, the FDA does largely come down on the IARC's side, acknowledging that "the IARC Report...add[s] to a body of literature suggesting that there may be a small to moderate risk of skin cancer, independently due to the use of tanning beds or lamps."

More Industry Headlines