By Dr Ananya Mandal, MD
One of the major risk factors for skin cancer is exposure to the sun’s harmful UV rays. The best method for prevention of skin cancer is to protect oneself from such exposure.
Steps and measures to reduce sun exposure include the following;
To limit sun exposure one should avoid being in direct sunlight for too long. This is particularly important between the hours of 10 am and 4 pm when the UV light is at its strongest.
A simple shadow test may be applied to check the directness and intensity of the sun. If one’s shadow is shorter than their body size the sun’s rays are the strongest and protection is necessary. The UV rays become more intense in the spring before temperatures get warmer and people may get sunburns before summer sets in mainly because they fail to protect themselves.
Areas with snow, sand (beaches), water etc. increase UV exposure due to reflected light and more protection is needed. UV rays can also reach below the water’s surface, pass through windows, windshields etc. Before venturing outdoors the UV index may be checked in the local newspaper, TV, radio, and online forecasts. It is also available on the EPA’s web site at www.epa.gov/sunwise/uvindex.html and in a variety of smartphone apps.
Sun protection of an individual
A simple way of sun-protecting oneself is to go the Australian “Slip! Slop! Slap! Slide” way. Here the words mean Slip on a shirt, Slop on sunscreen, Slap on a hat and Slide on sunglasses to protect the eyes and sensitive skin around them.
Each of these measures protects against sun’s UV rays. For example, one should wear clothing that covers as much of the body as possible. Long-sleeved shirts, long pants, or skirts cover the most skin and are the most protective. Dark colors are more protective and are preferred. A tightly woven fabric and dry protects better than loosely woven cloth or wet clothes.
Some clothings are available to special UV protection. These sun-protective clothes may have a label listing the UV protection (UPF) value that ranges on a scale of 15 to 50 and over. The higher the UPF, the higher the protection from UV rays. Swimming costumes are available with UV protection. Some new laundry detergents may also increase the UV protection of clothing.
Babies less than 6 months of age should be kept out of direct sunlight and protected from the sun using hats and protective clothing.
The next important step is to use sunscreen. This is the most vital step in sun-protection. It is important to know the level of protection offered by a sunscreen. Sunscreens are available in many forms like lotions, creams, ointments, gels, sprays, wipes etc. Some are available in cosmetics as well including powders, foundation, lipsticks etc.
Most dermatology associations, including the American Academy of Dermatology, recommend using broad-spectrum sunscreen products which help protect against both UVA and UVB rays. These have a sun protection factor (SPF) of at least 30. The SPF number is the level of protection the sunscreen provides against UVB rays.
When applying a SPF30 sunscreen, it should be smeared on thickly to get approximately 1 minute of UVB rays for each 30 minutes spent in the sun. SPF 15 sunscreens filter out 93% of UVB rays, while SPF 30 sunscreens filter out 97%, SPF 50 sunscreens 98%, and SPF 100 filters around 99% of the UVB rays.
Ideally 1 ounce of sunscreen (around one palm full) should be used to cover the arms, legs, neck, and face of the average adult. Most sunscreens must be reapplied at least every 2 hours and more frequently if one is swimming or sweating. Waterproof sunscreens protect for 80 minutes while those that are not protect for 40 minutes.
Sunscreens that contain avobenzone (Parsol 1789), ecamsule, zinc oxide, or titanium dioxide protect from both UVA and UVB rays. Sunscreens past their expiry date may still be effective to a lesser extent for 2 to 3 years. Before use the bottle needs to be shaken to remix the sunscreen ingredients.
Some individuals are allergic to products used in sunscreens. To check for allergies a small amount can be applied over the soft skin on the inside of the elbow. If the skin does not turn red or itchy, the product is suitable for the individual.
Using a hat
A hat with at least a 2- to 3-inch brim all around is best protection against the sun. It can protect the ears, nose, forehead, and the scalp. Hats with a non reflective and dark underside also help to lower the amount of UV rays reaching the face from reflections of water, sand and snow. A cap like a baseball cap with about 7 inches of fabric over the sides and back also protects the face and neck.
UV-blocking sunglasses protect the eyes and the soft skin around them. Sunglasses with UV protection should block 99% to 100% of UVA and UVB radiation. Labels that say “UV absorption up to 400 nm” or “Meets ANSI UV Requirements” mean 99% blockage of the UV rays.
Cosmetic glasses block about 70% of UV rays. Large-framed and wraparound sunglasses are more protective. Some contact lenses also block UV rays but these do not cover the whole eye and do not provide enough protection when used alone.
Tanning beds and artificial sunlamps should be avoided
Tanning lamps give out UVA and usually UVB rays as well. These can seriously harm the skin and cause skin cancer. Tanning bed use has been linked with an increased risk of melanoma especially if used by young adults (less than 30) and adolescents.
Several tanning pills claim to give a tan without exposing a person to UV radiation. These mostly contain color additives similar to beta-carotene. The Food and Drug Administration (FDA) does not approve any of these products for tanning.
Routine self skin examination
Routine self skin examination is another important measure for detection of any skin changes or changes in moles, scars, marks, blemishes, freckles early. If detected early most skin cancers are easier to treat.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Jan 21, 2013