College freshman Charlotte Drennon knows the value of staying out of the sun. Several family friends who are in their 70s avoided dark spots and minimized wrinkles, cutting decades off their appearance, just by diligently guarding against sunburns. And one of her family members died at just 20 years old after getting skin cancer the doctors blamed on prolonged exposure to the sun.

"Tanning is fine as long as you don't get too much of it too often," Drennon said. Because she knows the hazard, the pre-med major at Dordt College, in Sioux Center, Iowa, never tried indoor tanning and avoids spending extended periods in the sun.

Drennon's habits are moderateand unusual. According to a study released last week by the Centers for Disease Control, half of all Americans under 30 have been sunburned within the last year.. And, while Americans hold steady in a failure to protect themselves on the beach, they are actively increasing their ultraviolet ray exposure in another area-tanning salons.

Researchers proved tanning beds caused cancer in a 2009 analysis that compiled 20 medical studies. They found a 75 percent increase in skin cancer for those who begin using tanning beds before age 30. Th proof of this long-suspected link between tanning and cancer received little fanfare and had little effect. The prevalence of tanning salons has continued to rise in the last three decades. So have cases of melanoma. But most people just don't seem to care.

"I don't know that we're making any headway," said Len Lichtenfeld, deputy chief medical officer for the American Cancer Society. He acknowledged himself "astounded" to hear recent reports that women in their 20s tanned indoors an average of more than twenty times in the last year.

America's annual sunburns, meanwhile, have gotten worse. Following a 5 percent recovery in 2005, the instances of sunburns are now stable at the same 50 percent statistic recorded in 2000. Despite the dangers, young adults still find bronzed skin appealing.

"Tans that appear natural definitely have the connotation of 'healthier and more active' in my mind," said Joel Shannon, a sophomore at Geneva College, in Beaver Falls, Pa.

Shannon shares a common view. For many, the risk of cancer doesn't detract from the social insistence that tan skin is attractive. The social standard of beauty has moved away from the white complexions it favored in the 1800s, as next month's blockbuster Snow White and the Huntsman will remind audiences. Today, only those who go too far and develop a tanning obsession face censure.

The orangey hue of Jersey Shore's cast prompted comparisons to Oompa Loompas, and a leathery woman accused of trying to tan her six-year-old daughter became last month's viral sensation. The woman, Patricia Krentcil, has been banned from more than 60 tanning salons around her New Jersey home. But aside from these and other similar extreme examples, society still considers tanning acceptable.

Soaking up some sun isn't all bad. Exposure to sunlight should be monitored, and doesn't require trips to a tanning salon. But in small doses, sunlight is still a good thing, experts say. Vitamin D deficiency is a common problem in countries with frequent cloud cover.

A prolonged vitamin D deficiency can increase the risks of depression, weakened bones and, ironically, cancer. But only fifteen or twenty minutes of direct sunlight a day are needed to avoid the vitamin deficiency.

Experts say Americans are more at risk of overexposure than underexposure. Past and present studies haven't convinced many that they're putting themselves in danger. The 'it will never happen to me' mindset has a strong grip on both tanning salon customers and beach goers. As Shannon puts it, "Cancer seems a far-off, unlikely 'reality' when compared to the immediacy of looking healthier and more attractive now."

The Associated Press contributed to this report.