Sun Exposure Safety
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 possibility 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 year causes 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.
Additional barriers to the sun must be addressed and changed before behaviors will change. Attitudinal barriers to sun protection include the beliefs that it is necessary to use sunscreens only while at the beach or pool rather than year round, "a suntanned body is a healthy body," and "you can only get a sunburn in the summer". To overcome these barriers, education must begin early so habits can be developed early and consistently. Still, it is never too late to start sun protective habits.
The best sun protection is provided when all the sun-safe behaviors are practiced together. Sun protection habits include
- Limit sun exposure during the hours when the sun's rays are the strongest, AM to PM. To the extent possible, people should limit their exposure to the sun during these hours and practice all of the sun protective behaviors. Your shadow is an indicator of the sun's intensity. If your shadow is shorter than you are, the sun is at its highest intensity. The American Academy of Dermatology has established the Shadow Rule: No Shadow-SEEK SHADE.
- Refer to the daily UV index when planning outdoor events. The UV Index is a daily forecast of the intensity of the sun's UV rays. The Index indicates the risk of overexposure to skin-damaging UV radiation and can be used to help plan outdoor activities to minimize overexposure.
- Seek shade whenever possible. Shade structures such as trees, umbrellas and screen enclosures using sun shade material will provide year round protection. Although trees and screen enclosures do not offer complete sun protection, they provide about 60 to 80 percent blockage from the sun's rays.
- Wear a wide-brimmed hat, sunglasses, and long-sleeved, tightly woven clothing. Clothing can physically block out the sun's harmful rays and should be one of the first lines of defense against sun exposure. Sunglasses should block out 100 percent of UVA and UVB radiation to protect the eyes from damage. Hats are the best way to minimize UV radiation exposure to the face, head, ears, and neck.
- Use broad-spectrum sunscreens whose active ingredients block UVA and UVB rays. The Sun Protective Factor (SPF) should be a minimum of 15. Sunscreens should be used every day, including cloudy days. They should be applied liberally and evenly before going out into the sun and should be applied frequently, especially after swimming.
- Avoid tanning salons. Artificial UV radiation is just as bad for your skin as sunlight. Most tanning devices use UVA rays which have been shown to go deeper into the skin and contribute to premature wrinkling and skin cancer (AAD, 1994).
- Limit exposure to the reflective surfaces like snow and water. UV rays can be reflected off of sand, tile, water, snow, and buildings. It is important to practice all the sun protective behaviors even when you are in the shade.
For more information on Sun Safety, please visit the Skin Cancer Foundation's website or the National Safety Council website.