Fun in the sun: Make sure you're protected outside

Published June 6, 2008
By Capt. Jessica L. Berryman
72nd Medical Group

TINKER AIR FORCE BASE -- Summer is finally here! And in Oklahoma that means 90+ degree temperatures and a lot of humidity! But before you venture out into the sun did you know that skin cancer is the most common form of cancer in the United States? One in five Americans will develop skin cancer in their lifetime.
   Contrary to popular opinion, the majority of your sun exposure does not occur before the age of 18--only about 23 percent of lifetime exposure occurs by age 18. Therefore, before you head outside this summer to enjoy the sun and fun let's address some common questions related to sun protection.
   What are the damaging components of the sun's rays?
   The sun produces two types of ultraviolet radiation, UVA and UVB. These rays not only damage your skin, but they also increase your risk of skin cancer . Sunburn is caused mostly by UVB rays, while UVA rays are associated with wrinkling, leathering, sagging, and other effects of photoaging . UVA rays also compound the cancer causing effects of UVB rays, and increasingly are being seen as a cause of skin cancer on their own. Different sunscreens will vary in their ability to protect against UVA and UVB rays.
   What does SPF mean?
   Most sunscreens with an SPF of 15 or higher do a wonderful job of protecting against UVB. SPF -- or Sun Protection Factor -- is a measure of a sunscreen's ability to prevent UVB from damaging the skin. Here's the deal: If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer -- about five hours.
   It is important to remember that no sunscreen can block all UV rays. Regardless of strength, no sunscreen should be expected to stay effective longer than two hours without reapplication.
   And don't forget that plenty of damage can be done without ever seeing the reddening of a sunburn develop.
   Should everyone use sunscreen?
   Anyone over the age of six months should use a sunscreen daily. UVA is not blocked by most windows and that is why it is important to wear sunscreen even if you work inside.
   What Kind of Sunscreen Should I Use?
   In all cases it is recommend that you use a broad-spectrum sunscreen that offers protection against both UVA and UVB rays.
   There are quite a few after-shave lotions and moisturizers that have a sunscreen (usually SPF 15 or greater) already in them. For daily use involving a few minutes in the sun, here and there these are usually sufficient. If you spend a great deal of time outdoors, you need stronger, water-resistant sunscreen. However, water-resistant sunscreens may not be as good for everyday wear. They are stickier, don't go as well with makeup, and need to be reapplied every two hours.
   How much sunscreen do I need and how often should I put it on?
   To ensure that you get the full protection of sunscreen, you need to apply 1 oz , which is about a shot glass full. Studies show that most people apply only half to a quarter of that amount! This means that the actual SPF they have on their body is lower than advertised.
   Sunscreens should be applied 30 minutes before sun exposure to allow time for the ingredients to fully bind to the skin. Reapplication of sunscreen is just as important as putting it on to begin with, so reapply the same amount every two hours. Sunscreens should be reapplied immediately after swimming, toweling off, or sweating a great deal as well.
   Common myths
   If it's cold or cloudy outside, you don't need sunscreen.
FALSE! Up to 40 percent of the sun's ultraviolet radiation reaches the earth on a completely cloudy day.
   80 percent of your sun exposure comes as a child, so it's too late to do anything now.
FALSE! A recent multi-center study showed that we get less than 25 percent of our total sun exposure by age 18. Since Americans are living longer it will become more important than ever to protect your skin as you age.
   In summary, before you head out the door this summer, make sure that you buy a high-quality product with an SPF of 15 or higher, check the ingredients to make sure it offers broad-spectrum protection, and decide whether it works better for everyday use or extended outdoor use. Once you choose the right sunscreen, make sure you use it the right way. By following these guidelines you can lower your risk of developing skin cancer, while helping your skin look younger for longer.
(Adapted from www.skincancer.org)