July 12, 2011
By Claire McCarthy, M.D.
Boston Children's Hospital
It feels good to be out in the sun. It even makes us feel healthy. And being outside is good for us. There are more opportunities for vigorous exercise outdoors than indoors, and the sun helps our body make vitamin D, which is crucial for our health.
Too much sun, though, isn't good for us. It can cause:
- Early aging of the skin
- A higher risk of skin cancer. The skin cancer we worry most about is melanoma, which can be fatal if not detected and treated early.
Ultraviolent radiation (UVR) in sunlight is what causes trouble. There are two types of UVR that make it to earth:
- UVB causes sunburns and skin damage that lead to cancer.
- UVA causes premature aging and interferes with the skin's protective factors, thus increasing the risk of cancer.
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Sun Exposure and Children
Children exposed to too much sun have an increased risk of skin cancer in adulthood. Rates of skin cancer are rising. According to a recent article in the journal Pediatrics, 1 in 33 newborns today will get melanoma when they grow up. For children born in 1935, that risk was 1 in 1,500.
Infants and toddlers are particularly vulnerable to UVR because:
- The outer protective layer of the skin (stratum corneum), isn't fully developed yet.
- They have less melanin, the chemical in the skin that can help protect against the sun.
- Compared with adults, they have more skin surface in proportion to body weight.
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The Truth About Sunscreens
Sunscreen can make a huge difference when it comes to preventing sunburns and skin cancer. But before you choose one, consider the following facts and some recent changes made by the U.S. Food and Drug Administration (FDA).
Sun Protection Factor (SPF)
SPF is a measure of how much protection from the sun the sunscreen gives. For example, an SPF of 15 means you are 15 times more protected than you would be without sunscreen.
There are two important facts about SPF, however, that many people do not know:
- SPF only applies to UVB rays. It does not measure protection against UVA rays. Many sunscreens say that they offer "broad-spectrum" protection, but just how much UVA protection they provide is not known.
What's new? Starting at the end of 2012, sunscreens are going to have to prove that they really do offer broad-spectrum protection in order to make the claim. They will have to pass the FDA's broad-spectrum test.
- The difference in protection between an SPF 30 and an SPF 50 is very small. The difference between 50 and 100 is negligible.
What's new? The new regulations state that the highest SPF a sunscreen can promise is 50+.
Sunscreens will no longer be able to call themselves sunblocks. No sunscreen completely blocks the sun.
"Waterproof" and "water-resistant" claims
All sunscreens wash off with water. So sunscreens will no longer be able to claim that they are "waterproof." And with the new regulations, "water-resistant" sunscreens will have to say which category they fall into:
- Those that should be reapplied after perspiring for 40 minutes or being in the water
- Those that should be reapplied after perspiring for 80 minutes or being in the water.
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Be Smart About Sun Protection
To reduce your child's risk of sunburn or skin cancer later in life, here's what you can do:
- Limit sun exposure between 10 a.m. and 2 p.m. This is when the sun's rays are most intense.
- Use broad-brimmed hats and lightweight tightly-woven clothing (long sleeves and long pants are best) to protect against the sun.
- Look for sunscreens that say "broad-spectrum" and "water-resistant," with an SPF of at least 15 (but don't pay extra for anything over 50); reapply frequently.
- If you're going to be in the sun with your infant or toddler, use a children's sunscreen product on the uncovered skin. (In the past, parents were advised not to use sunscreen on infants less than 6 months old. But that recommendation has been changed slightly.) Try a little bit of the sunscreen on an arm or leg ahead of time to be sure your baby doesn't have a reaction to it. (Call your doctor for advice if there is a reaction.)
Being outside is good for kids, especially when it comes to exercise. So don't let the talk about skin cancer scare you. With some common sense and good sunscreen, your child can be safe outdoors.
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Claire McCarthy, M.D., a senior medical editor for Harvard Health Publications, is an assistant professor in pediatrics at Harvard Medical School. She is an attending physician and Medical Communications Editor at Children's Hospital Boston.