Before discussing the effects of tanning equipment and increased sun exposure, we first must understand ultraviolet light and how it affects your skin. Sunlight contains two types of ultraviolet (UV) light: UVA and UVB. UVA rays are longer wavelengths that penetrate deep into the dermal layer of skin. Limited exposure to UVA rays cause skin to tan; please note that most experts agree that overexposure to UVA, however, can lead to long-term skin damage. UVB rays wavelengths are far shorter, only affecting the outermost layers of skin. UVB rays are the "sunburn rays" that are considered more harmful. Tanning beds generally emit 93% to 99% UVA radiation, increasing the safety of a tan that is controlled, and about three times the UVA radiation given off by the sun.

Suntan or sunburn?

It is also important to understand what happens to the skin as it is tanned or burned and what the long-term, harmful effects may be. UVB rays are most responsible for skin’s burning. These short-wavelength rays actually pop the capillaries just beneath the surface of the skin. Long-wavelength UVA rays have totally different results. As UVA rays penetrate into the skin, melanin granules turn golden brown. However, keep in mind that UVB rays are required to stimulate these melanin granules to rise to the skin’s surface, especially if you possess only small amounts of the pigment, melanin.