Sun protection factor

Sun Protection

Protection from the damaging ultraviolet rays of sunlight.

Scientists have found a strong link between exposure to direct and reflected sunlight and a number of health risks. Ultraviolet (UV) radiation, a component of sunlight, causes damage to the skin and increases the risk of skin cancer. UV radiation comes in two forms—ultraviolet A (UVA) and ultraviolet R (UVB). UVB is the radiation sunscreens are designed to screen out. The United States Food and Drug Administration has not approved a rating system for UVA protection because experts have not reached a consensus as to what constitutes a good test. Manufacturers can claim protection against "broad spectrum" radiation if their product contains one of the following ingredients: benzophenone, oxybenzone, sulisobenzone, titanium dioxide, zinc oxide, and butyl ethoxydibenzolmethane (also called avobenzone and known by the trade name Parsol 1789).

One of the factors that increases the risk of skin cancer is the number of sunburns experienced during childhood. For the first six months of life, infants should be protected from all sun exposure, according to recommendations from the American Medical Association and the American Cancer Society. The AMA studies predict that one in six of all individuals born in the late 1980s and

1990s will develop skin cancer at some point in their lives, compared with one in 1,500 for those individuals born in the late 1940s and 1950s. This increase is due to many factors, including the deterioration of the earth's protective ozone layer, the trend toward wearing lighter clothes that leave more skin surface exposed, and the increase in the amount of time people spend outdoors.

In the late 1990s, about one million new cases of skin cancer were being diagnosed each year. Dermatologists reported that skin cancer was as common as all other cancers combined. From 1980-89, the incidence of skin cancer increased dramatically; melanoma skin cancer increased 21%, and non-melanoma (basal cell and squamous cell) skin cancer increased 65%. The accompanying tables provide information on risk factors and the National Weather Service UV level index rating system. The UV index is routinely reported in major cities in the United States, and is included in weather forecasts on television and radio. By monitoring the UV levels in the geographic area, residents can respond with the appropriate degree of protection necessary.

Sunscreens are rated by a sun protection factor, or SPF, which is a multiplier of the amount of time the skin can be exposed to the sun before experiencing sunburn. The American Academy of Dermatology recommends that everyone use a broad-spectrum sunscreen having a sun protection factor (SPF) of at least 15. The Academy also recommends that consumers check sunscreen labels for ingredients that protect from UVA rays as well as UVB. It is important to note that the SPF is not cumulative; in other words, reapplying a sunscreen after being in the sun for a period of time does not extend the sun protection factor; it will only replenish the protection that may have been washed away by perspiration or during swimming. The only way to get protection for a longer period of sun exposure is to choose a sunscreen with a higher SPF factor.

While sunscreens protect against sunburn, they do not necessarily prevent skin cancer. Even when a person

uses sunscreen for the purpose of spending more time in the sun, the skin can still collect damaging radiation. Dermatologists advise wearing protective clothing and head covering during the midday hours (from 10 A.M. to 3 P.M.), and the consistent use of sunscreens year-round. To protect children from the damaging effects of the sun, apply sunscreens with an SPF of at least 15 and encourage them to wear hats with visors. It is also recommended that even young children wear sunglasses that are designated as providing protection from UV radiation. Although many children may want to play outdoors wearing little clothing, parents should encourage them to keep as much skin area covered by clothing as possible.

New fabrics are being produced that are comfortably lightweight but also offer protection from UV radiation. As these fabrics are used to a greater degree, parents can watch clothing labelling for this protection factor.

Content licensed from:

Author Info: , Thomson Gale, Detroit, Gale Encyclopedia of Childhood and Adolescence, 1998

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.