Another important factor Dr. Tanzi emphasized is that UVB protection does not increase proportionately with a designated SPF number. For example, an SPF of 30 screens 97 percent of UVB rays, while an SPF of 15 screens 93 percent of UVB rays and an SPF of 2 screens out 50 percent of UVB rays. However, not applying enough sunscreen or not covering all exposed areas may result in a lower SPF than the product contains.

"For adequate protection, sunscreens are best applied 15-30 minutes prior to going outside, approximately every two hours or immediately after swimming or sweating," said Dr. Tanzi. "Research demonstrates that most people only apply 25 to 50 percent of the recommended amount of sunscreen, which is one ounce for the entire body or enough to fill a shot glass. Therefore, if only half the proper amount of SPF 15 is applied, the SPF has been reduced to an SPF of approximately 5, which is then inadequate protection. (1) "

To address the issue of people not using enough sunscreen or reapplying improperly, the Academy recently increased its recommended SPF to a minimum of 30 for proper sun protection. Dr. Tanzi said that while sunscreen is important to protect against skin cancer, it is only one part of what should be an overall sun-protection program. To minimize your risk of skin cancer, the Academy recommends that everyone Be Sun SmartSM:

Generously apply a broad-spectrum water-resistant sunscreen with a Sun Protection Factor (SPF) of at least 30 to all exposed skin. "Broad-spectrum" provides protection from both ultraviolet A (UVA) and ultraviolet B (UVB) rays. Re-apply approximately every two hours, even on cloudy days, and after swimming or sweating.Wear protective clothing, such as a long-sleeved shirt, pants, a wide-brimmed hat and sunglasses, where possible. Seek shade when appropriate, remembering that the sun's rays are strongest between 10 a.m. and 4 p.m. If your shadow is shorter than you are, seek shade. Protect children from sun exposure by playing in the shade, using protective clothing, and applying sunscreen. Use extra caution near water, snow and sand as they reflect the damaging rays of the sun which can increase your chance of sunburn. Get vitamin D safely through a healthy diet that may include vitamin supplements. Don't seek the sun. Avoid tanning beds. Ultraviolet light from the sun and tanning beds can cause skin cancer and wrinkling. If you want to look like you've been in the sun, consider using a sunless self-tanning product, but continue to use sunscreen with it. Check your birthday suit on your birthday. If you notice anything changing, growing, or bleeding on your skin, see a dermatologist. Skin cancer is very treatable when caught early.

Check the Academy's Web site (www.aad) for the latest list of sun protective products that meet the stringent, evidence-based criteria of the AAD SEAL OF RECOGNITION(R).

SOURCE American Academy of Dermatology