According to the American Academy of Dermatology, there are two types of ultraviolet radiations in indoor tanning: UVB rays and UVA rays.UVB rays are closely associated with sunburns. UVA rays are considered the "tanning" rays that leave skin looking darker.Recently, UVA rays have become a big concern because they get deeper in the skin and cause more damage than can be seen clinically

UVA rays are linked to basal-cell carcinoma, squamous-cell carcinoma and melanoma, the three most common types of skin cancer.All three types are going up in numbers, Aulisio said.They are also the most common cancers among young people, especially women.Another problem with indoor tanning is students become overly confident."Young people feel like they're invincible," Aulisio said. "They get a base tan now, and they think they don't have to wear sunscreen later."