Skin Cancer and Sunscreen

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Karen Schaefer: We've all done it. You grab a towel, sandals and sunglasses and head out for a day of fun in the sun. The only thing you forgot was the sunblock. An hour later and - ouch! Sunburn.

Doctors have known for years that sunburn is caused by exposure to the sun's ultraviolet rays. Tanning beds originally used the same ultraviolet radiation to give pale winter skins a golden glow. Then researchers discovered that shortwave ultraviolet rays - or UVB - were the source of burning. So salon owners began using tanning devices that emit mostly longwave uv radiation - or UVA. Those are the tanning rays. Both rays bombard your skin every time you go outdoors. But many sunscreens only protect against UVB. And doctors say that's a problem.

Kevin Cooper: Some sunscreens may be allowing a lot of UVA through. There's a question whether they have anything to do with cancers or the like.

KS: Dr. Kevin Cooper is head of Dermatology at University Hospitals in Cleveland. It's one of just a handful of U.S. hospitals that not only treats patients, but also conducts research into the link between skin cancers caused by sun exposure and the use of sunscreens. Dr. Cooper says the global increase in skin cancers - including the deadly melanoma - may be linked to a mis-use of sunscreen products.

KC: The concern that has been raised is that if you use sunscreens to stay out in the sun longer than you would have otherwise, then you may be allowing more rays of the sun that are not filtered by the sunscreen.

KS: This year, the Centers for Disease Control predict that more than 50,000 Americans will be diagnosed with skin cancer. One fifth of those will die from the disease. That's why the federal Food and Drug Administration proposed last year to limit SPF values on sunscreen products to 30. Officials were worried that higher SPF ratings on some products were leading consumers to spend more time in the sun than they should. But SPF - or skin protection factor - numbers apply only to UVB rays. Dr. Henry Lim is a researcher and physician at the Henry Ford Health System in Detroit, where he chairs the Department of Dermatology.

Henry Lim: Unlike the SPF number, which is very tightly regulated and there is a very strict guideline as to how should one measure that SPF number, there is no such guideline for the measurement for UVA protective sunscreens.

KS: Dr. Lim says the medical community has asked the FDA for similar labeling standards on UVA sunscreen products.

HL: We had a consensus conference that was sponsored by the American Academy of Dermatologists which I chaired and Dr. Cooper participated in. And the purpose of that was precisely to look at what is the science in UVA protection. And based on that, we made a number of recommendations to the FDA, which the FDA I'm sure would use in their deliberation.

KS: The FDA was to have issued the new labeling standards for UVB protection last December. But the agency decided to extend the public comment period to gather the latest research on how best to measure sunscreen protection against UVA. They hope to complete new standards for both by the end of this year. In the meantime, Dr. Kevin Cooper says there are broad-spectrum products on the market now that combine UVB protection with compounds that scatter or absorb UVA light.

KC: Agents like zinc oxide or titanium dioxide, they take the light, it's like a little mirror that reflects back and absorbs it. The other ingredient is parsal. And parsal is a UVA-absorbing sunscreen and this is one that absorbs rather than reflects. And it absorbs actually further unto the UVA than zinc oxide, titanium dioxide compounds.

KS: Not everyone shares the same risk of skin cancer. People with fair skins, freckles or a lot of moles have a higher risk of developing malignant melanoma. So do people with a personal or family history of skin cancer or those who burned frequently as a child. So while sunscreens can help, Dr. Cooper suggests there are other ways to limit sun exposure.

KC: You want to stay out of the sun when it's most intense, 10-3. And you can protect yourself with a block like a hat or shade or an umbrella, long sleeves. Those are key components that we don't want people to forget and the sunscreen is a help.

KS: Despite all the warnings, some people still haven't gotten the message that too much sun can kill. But for those who have, there are plenty of ways to protect yourself - and prove that pale can be beautiful, too.

Person: I like that white glowing skin.

KS: In Cleveland, Karen Schaefer, 90.3, WCPN News.

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