The study comes amid recent proposed legislation demanding a closer look at warning labels on indoor tanning beds.

   "If you're of age, you can go to a bar and drink and smoke. But if you're not of age, you don't have the same reasoning. You need guidance from society -- either from parents or the law -- about whether you should expose yourself to something you know causes cancer," said study author Robert P. Dellavalle, a dermatology professor at the University of Colorado at Denver and Health Sciences Center.

   Dellavalle and colleagues found nearly half of 23 high school newspapers in the Denver area published tanning advertisements, mostly for tanning by UV radiation, a carcinogen recognized by the International Agency for Research on Cancer. Any UV radiation, be it from the sun or from a tanning booth, is a risk factor for melanoma, the study said.

   The study, published in the April issue of the Journal of the American Medical Association, is the first to look at tanning advertisements in high school newspapers. Scott Freeman was the lead author.

   Melanoma is the leading cause of cancer death for women aged 25-30, according to the Melanoma Research Foundation. Although they may not develop cancer for 30 or more years, women who use tanning beds more than once a month are 55 percent more likely to get malignant melonama, skin cancer's deadliest form, according to the National Cancer Institute. Tanning among teenagers has also risen dramatically: in one study of adolescents in the Minneapolis-St. Paul area, up to 42 percent of high school-aged girls had tanned indoors. 

   The tobacco industry's youth advertising inspired Dellavalle to find out if the same Joe Camel-type marketing also occurred with tanning salons. 

   "It made us think how things might have been 50 years ago, when the tobacco industry was coming out with cartoon character ads," he said.

   The ads, published between 2001 and 2005, often featured scantily clad women and offered unlimited tanning specials for prom with the use of a student ID.

   Some of the ads were for non-UV tanning -- or DHA spray-on tans -- that are not carcinogenic, although their long-term effects aren't completely known. The spray-on tan, whose technology has improved greatly and now mimics a natural tan, is still a viable alternative to UV tanning. 

   For many teens, tanning has become the social scene. 
   "They can't do much else, so they say, 'We might as well hang out at the tanning parlor,'" Dellavalle said. Some tanning companies are helping: Dellavalle referenced a New York company, Tanning Bed, which offered $250 in college money to graduating high school seniors for a winning essay on a business proposal.

   John Overstreet, executive director of the Indoor Tanning Association, a group representing the tanning industry, said teens are a small part of industry business: around 5 percent of those under 18 tan, he said.

   But the escalating cost of treating skin cancer requires a public policy response, Dellavalle said. Some states, such as California and Illinois, have banned teens from tanning booths. Colorado has no such law.

   And in February, Reps. Carolyn Maloney (D-N.Y.) and Ginny Brown-Waite (R-Fla.) proposed the Tanning Accountability and Notification Act, which would require the Food and Drug Administration to review whether the current labeling on tanning beds provides enough information about the dangers.

   "American women -- and that certainly includes teenagers -- are bombarded with advertising for tanning salons and are sometimes even fed false information, but they are rarely given the full story," Maloney said in a statement. "Dermatologists say that just one time in a tanning bed has the potential to cause harm, and the public needs to be properly warned."

   The FDA does put labels on sunlamps that specify an exposure schedule, as well as require protective goggles.

   This labeling is enough, Overstreet said, especially since the science behind melanoma and cancer is not clear.

   "We the public have been subjected to a 25-year, well-financed PR campaign to scare us out of the sun," Overstreet said. "But in the last 2-3 months, more and more is coming out about the benefits of moderate exposure to ultraviolet light," he added.

   Overstreet referred to the possible protective effects of vitamin D, a nutrient absorbed through sunlight. However, tanning beds might not be an effective outlet for vitamin D.

   Recent research has also suggested tanning may have an addictive effect. Endorphins, the body's natural narcotic, could explain why people lay in the sun in the hottest part of the day, said Steven Feldman, a professor of dermatology, pathology and public health sciences at Wake Forest University School of Medicine. In a recent blinded trial, he found women select tanning beds with UV radiation when given a choice between a UV bed and a bed blocked from UV.

   Dellavalle doesn't expect America's quest for bronzed bodies will falter.

   "There is something inherently attractive in tan-looking skin, and it's hard to change what people think is good-looking," he said.

   As for Feldman, he plans to do more research, but he's not overly concerned about the phenomenon.