Sunburn and Sun Poisoning (cont.)

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What is sunburn?

Sunburn is an inflammation of the skin that is caused by overexposure to ultraviolet (UV) radiation from the sun. A similar burn can follow overexposure to a "sun" (UV or tanning) lamp. UV radiation can also damage the eyes, although no surface burn is apparent.

Sunburn is a very common condition. According to the US Centers for Disease Control and Prevention (CDC), in the United States, approximately 50% of adults age 18 to 29 report having at least one sunburn in the preceding year.

Can sunburn cause permanent damage?

Yes. Sunburn early in life increases the risk of developing skin cancer later on. Repeated overexposure to ultraviolet rays can also scar, freckle, dry out, and wrinkle the skin prematurely. In addition, frequent overexposure to ultraviolet rays can increase the risk of developing eye cataracts and macular degeneration, a leading cause of blindness.

What is UV light?

UV light is radiation energy in the form of invisible light waves. UV light is emitted by the sun and by tanning lamps.

The sun discharges three types of ultraviolet radiation:

  1. ultraviolet A (UVA),
  2. ultraviolet B (UVB), and
  3. ultraviolet C (UVC).

Only UVA and UVB rays reach earth. (UVC does not penetrate the earth's upper atmosphere.)

Although research has long implicated UV-B as the most likely form of UV radiation to damage the skin and cause skin cancer, it is now known that UVA also can be dangerous. UVB is known to affect the outer layer of skin. UVA is much less intense than UVB, but it is about 50 times more likely than UVB to reach deeper layers of skin to cause sun damage.

Tanning lamps also produce UVA and/or UVB. These artificial rays affect the skin in the same way as do UVA and UVB from the sun.

When and where are UV rays most intense?

UV rays are most intense at noon and the hours immediately before and after (between 10 a.m. and 4 p.m.), particularly in the late spring, summer, and early autumn. Although they are less concentrated at other times of the day and year, UV rays can still damage the skin and eyes - even in the dead of winter and on cloudy or rainy days.

UV rays also increase in intensity in relation to altitude and latitude. The higher the altitude, the greater is the concentration of UV rays. Likewise, the rays are more powerful the nearer to the equator.

UV rays "bounce" off reflective surfaces - including water, sand, and snow. Thus, a skier, swimmer, fisherman, or beachcomber may be bombarded with UV rays from above and below.

Medically Reviewed by a Doctor on 7/19/2012

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