When radiation hits your skin, your body senses that it is being injured, so it tries to protect itself. To do this, it produces melanin, which is a natural sun block. The dark pigment that skin cells produce to block out dangerous rays cause tanning. But the sun isn't the only culprit that damages skin cells. Many people use local tanning salons to obtain that awesome tan.
Tanning booths bombard the body with ultraviolet rays, similar to that found naturally in sunlight.
Radiation from tanning booths can be more intense at the surface of the skin, and will produce its effect in a shorter amount of time. The deadliest of these is melanoma. Squamous-cell carcinoma is also deadly but much slower growing and less aggressive. Your best defense against cancer is to either stay away from UV radiation, or to limit the amount of time spent in the sun unprotected. The most common type of protection from skin's harm is to use a sunscreen.