Sun Safety
Risks from Overexposure
to UV Radiation
Exposure to UV radiation appears to be the most important environmental factor in the development of skin cancer and other UV related adverse health effects. Besides the immediate effect of sunburn, over time excess ultraviolet radiation can cause skin cancer, eye damage, immune system suppression, and premature aging.
Skin type is the most important factor in determining a person's risk for skin cancer. Skin types range from those individuals that burn easily and never suntan to those who do not burn at all. Some individual characteristics that are risk factors for skin cancer include
- fair skin,
- blue, green, or hazel eyes,
- light-colored hair,
- tendency to burn rather than suntan,
- history of severe burns, many moles,
- freckles,
- a family history of skin cancer.
Even people with dark complexions can get a sunburn. No one is exempt from the possibilty of getting skin cancer or other serious health problems from the sun's UV rays.
The level of UV radiation that reaches the earth's surface is dependent on several factors.
- Ozone:The stratospheric ozone layer protects all life on earth from excessive exposure to UV radiation from the sun.
- Intensity: The sun's intensity varies throughout the day much like visible light. Around noon, the sun is at its highest, so the sun's rays have less distance to travel through the atmosphere and the intensity is highest.
- Time of year: Time of yearcauses the UV rays to vary.
- Geographical location: The sun's rays are strongest at the equator, where the sun is most directly overhead.
- Altitude: UV intensity increases with altitude because there is less atmosphere to absorb the damaging rays.
- Weather: Cloud cover reduces the amount of UV radiation reaching the earth.
- Reflection: UV rays are reflected off surfaces such as snow, water, sand, and concrete.
National Safety Council
1025 Connecticut Avenue, NW, Suite 1200, Washington, DC 20036
(202) 293-2270 (tel); (202) 293-0032 (fax)
