Beware of ultraviolet light. Limit your exposure, and, please, use sunscreen.

USA Today reports on a study by the Mayo Clinic that takes decades of research to come to the conclusion that melanoma cases, especially in young women, are on the rise.

A dramatic rise in skin cancer rates among young adults is leading health officials to shed light on the risk factors, specifically tanning salons, which women are more likely to use.

Women under 40 are hit hardest by the escalating incidence of melanoma, according to a Mayo Clinic study published in the April issue of Mayo Clinic Proceedings, out today.

Researchers examined records from a decades-long database of all patient care in Olmsted County, Minn., and looked for first-time diagnoses of melanoma in patients 18-39 from 1970 to 2009. Melanoma cases increased eightfold among women in that time and fourfold for men, the authors say.

"We need to get away from the idea that skin cancer is an older person's disease,'' says report co-author Jerry Brewer, a dermatologist at the Mayo Clinic in Rochester, Minn.

Of course, the tanning industry disagrees with these findings, but the Jersey-Shore-watching-public already knew that, right? Read on for what exactly the "Jersey Shore effect" is.