Sunlight consists of two major types of radiation: ultraviolet A, or UVA (U-V-A), and UVB (U-V-B). Tanning beds are often touted as a safe alternative to the sun because they use mainly UVA radiation, which is less likely to cause sunburn than UVB. The fact is, all UV radiation is harmful to the skin, whether it comes from the sun or a tanning bed. While UVB is the major cause of sunburn, UVA light in excessive quantities can also eventually burn you. Furthermore, both UVA and UVB are responsible for cataracts and premature aging of the skin. Over time, they create wrinkles, sagging, liver spots, and a leathery texture. Though UVB is most closely associated with basal- and squamous- (SKWAY-muhs) cell skin cancers, doctors suspect that UVA light may also play a role in skin cancer. UVA is known to penetrate deeper into the skin, impairing the skin's immune system and damaging blood vessels. The important thing to remember is that there's no such thing as a safe tan. The release of melanin pigment that we call tanning is your body's attempt to protect itself against UV light. Therefore, the presence of a tan indicates that the skin has already been damaged.