Skin is a body organ and is composed of three main layers. The epidermis is the top layer and includes the surface of the skin. The dermis is the middle layer, and the lower layer is called the subcutaneous layer or hypodermis. Skin performs important body functions such as regulating body temperature and protecting bones, muscles and organs. Ultraviolet light from the sun and from tanning beds is a form of radiation. Light from the sun is in three main forms--UVA, UVB and UVC. These classifications are determined by the wavelengths of sunlight radiation, with UVA having the longest wavelength and UVC having the shortest. The atmosphere blocks all UVC rays and most UVB rays.
Tan
Skin tans as a result of exposure to tanning beds. The tanning is a process the skin undergoes to increase the amount of skin pigmentation, called melanin, in the epidermis as a result of exposure to UV radiation. A tan provides a degree of protection against the harm that UV rays can do to the skin, and it lowers the levels of sun protection factor that are needed in a suntan lotion.
Skin Damage
According to the UAB Health System, a tan is the skin's response to the injury that the radiation causes. Every tan accumulates damage to the skin. The Library of Medicine points out that whenever there is a tan, skin cells have been killed and others have been damaged. Sunburns can occur, too. They occur when the body sends blood to the epidermis because of the damage caused by UV rays.
Premature Aging
UV rays break down collagen and elastin fibers in the skin. Those two substances help give skin its elasticity and provide a youthful appearance. Prolonged exposure to the UV rays in tanning beds results in premature aging, giving skin a leathery feel, dark spots and wrinkles.
Cancer Risk
The UV radiation from tanning beds has been associated with melanoma, a form of skin cancer. Although there are heredity factors in the predisposition to skin cancer, exposure to UV rays increases the risk. The skin cancer may result from the damage to DNA that UV rays cause. Another factor in the occurrence of melanoma may be the weakening of the immune system that UV radiation causes.
