Despite its strong correlation with skin cancer risk, tanning beds are available on campus or in off-campus housing at nearly half of the nation's top colleges, and access is frequently discounted or entirely free of charge, according to a recent study.

New research from UMass Medical School showed that among U.S. News and World Report's 125 top colleges, 48 percent had indoor tanning facilities either on campus or in off-campus housing surrounding the schools. More than half a million students have access to tanning beds on campus, representing 12 percent of the schools surveyed.

"We encourage universities to adopt a 'tan free campus' policy by prohibiting tanning beds and booths from campuses and discouraging housing facilities from having beds," Sherry Pagoto, lead author of the study and associate professor of medicine, said in a statement. "Universities should instead court new students with enticing health facilities such as gyms, swimming pools and healthy dining options."

Pagoto and her colleagues sought to document the availability of tanning beds for college students, since research has shown that the devices are especially hazardous to young people -- those who use them before age 30 increase their risk of melanoma (the deadliest form of skin cancer) by 75 percent. Skin cancer rates overall are soaring.

For the study, researchers examined the first 125 colleges in the U.S. News and World Report 2013 list of the best colleges and universities for undergraduate education in the United States to analyze how many schools offered tanning beds on campus or in nearby off-campus housing. They also examined how students pay for the services, and whether students were allowed to use campus cash cards, or were offered discounted rates.

They found that the Midwest had the highest percentage of schools with tanning beds located either on campus (26.9 percent) or off campus (61.5 percent), followed by the Northeast (13 percent on campus; 19.6 percent off campus.) The findings also indicated that colleges with higher enrollment had the highest prevalence of on-campus indoor tanning.

Among the 42 percent of colleges with tanning beds available in off-campus housing, nearly all offered unlimited use of the beds at no charge for student tenants, the study found. Results also showed that 15 percent of colleges referred students to off-campus housing that had indoor tanning facilities. Campus cash cards could be used to purchase tanning locally for 14 percent of the colleges.

Tanning is a widespread habit among young adults, especially non-Latino white women. While other studies have examined the tanning habits of college students, no study has examined the availability of tanning salons on or near college campuses, according to background information in the study.

The findings were published online Oct. 29 in JAMA Dermatology.