Medicine for the Outdoors
Medicine for the Outdoors

Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.

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Sun Exposure

Dr. Susan Swetter from Stanford is a professor of dermatology and renowned expert on sun exposure and the hazards of ultraviolet radiation. She recently published a brief summary of useful information entitled “Don’t get burned” which is a terrific short piece intended to encourage the use of sunscreens. I suggest that you read it.

Until then, here are the highlights:

1. Ultraviolet (UV) radiation causes sunburn, skin cancer, and photoaging (accelerated skin aging).

2. Ultraviolet A (UVA) radiation accounts for 95% of UV radiation, and UVB radiation for 5%. UVB radiation is the major culprit in causing sunburn and skin cancer.

3. One in five Americans will develop skin cancer, including basal cell and squamous cell carcinoma, or melanoma, in their lifetimes.

4. Risk factors for melanoma include fair skin and increased numbers of common and atypical moles.

5. Tanning bed use has been linked to skin cancer.

6. Suncreens must filter out the entire range of UVB and UVA wavelengths to be labeled “broad spectrum.” In America, the sunscreens that contain the chemical avobenzone that is photostabilized with octocrylene provide the best UVA protection.

7. Insufficient application is the most common mistake made when applying sunscreens. People generally only use about a fourth to a half of the amount of sunscreen needed to achieve the sun protection factor (SPF) level indicated on the product.  Dr. Swetter recommends applying 2 to 3 tablespoons to the body (use more if you have a large surface area) and 1 tablespoon to the face, reapplying every 2 to 4 hours.

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Tags: General Interest , Staying Safe

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About the Author

Dr. Paul S. Auerbach is the world’s leading authority on wilderness medicine.