Sun Exposure and Sun Protection
Sun protection is important to prevent the short and long-term damaging effects of sunlight. Sunscreens should be used in conjunction with protective clothing for optimal sun protection. Long-term overexposure can cause wrinkles, freckles, age spots, dilated blood vessels, changes in the texture of the skin, and skin cancers. The American Academy of Dermatology recommends that you avoid deliberate sunbathing, wear a wide-brimmed hat, sunglasses, and protective clothing. When you are exposed to sun, use a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 15 even on cloudy days. A broad-spectrum sunscreen is one that protects against both ultraviolet-A (UVA) and ultraviolet-B light (UVB).
The ability of a sunscreen to block ultraviolet radiation is expressed as an SPF (sun protection factor). This factor represents the ratio of the amount of radiation required to induce redness through a thin layer of sunscreen (2 mg/cm2), compared to unprotected skin. The actual amount of sun protection most people are getting with sunscreen does not reach the rated SPF because most people apply too thin a layer of sunscreen.
There are two primary components of sunscreens: chemical and physical agents. Most broad spectrum sunscreens (which block UVA and UVB radiation) contain chemical and physical sunscreen components.
It is recommended that you select a sunscreen with one or more of the following four components because of their ability to absorb UVA radiation:
• Chemical
• Avobenzone (Parsol 1789)
• Ecamsule (Mexoryl)
• Physical
• Zinc oxide
• Titanium dioxide
The chemical ingredients listed are often found in combination with other UVB blocking agents to produce broad spectrum UV protection.
Daily application of a facial moisturizer with an SPF of 15 or greater is recommended. For outdoor activities, an SPF of 30 or greater is recommended. 1 ounce or 30 mL (two tablespoons) of sunscreen is required to cover all body areas. If you are applying less than that amount, you are not getting the degree of sun protection indicated by the SPF designation.
A dual application of sunscreen with the first application 20 minutes before and the second application 30 minutes after the start of sun exposure is recommended.
