Thinking of heading for the beach this summer? Think you'll get adequate protection from your sunscreen? Think again.
Americans have been smoothing on sunscreens and sun blocks for years to guard against skin wrinkling and skin cancer. Sales of sun care products continue to rise, leaping 12 percent last year, according to Drug Store News, a trade publication.
Yet in Western countries the number of people developing melanoma, the most deadly type of skin cancer, is climbing faster than for any other cancer.
From 1973 to 1995, incidence in this country rose 126 percent, according to the National Cancer Institute.
The American Cancer Society estimates there'll be 47,700 new cases this year and about 16 percent (7,700) will die from it.
"The most likely explanation (for the increase in melanoma cases) is that sunscreen protects against sunburn so people stay out in the sun longer," said Dr. Henry W. Lim, a dermatologist and chairman of the Department of Dermatology at Henry Ford Health System in Detroit.
But it also has become clear that people should be using sun protection products that guard against both UVB and UVA, two types of ultraviolet radiation, he said. In other words, products must offer "broad-spectrum" protection.
Unfortunately, even when consumers know to buy such a product, it's not clear from the label just what they're getting, he said.
UVB rays are the ones believed most likely to cause sunburn, and scientists have long thought they can cause melanoma and other less severe skin cancers. (Squamous cell and basal cell cancers are more common and less serious.)
UVA rays have a longer wavelength that can penetrate deeper into the skin and damage elastic fibers.
Scientists think UVA may add to skin damage that can lead to wrinkling and leathering.
How can you know you're getting an effective broad-spectrum product? For now, the best advice may be to check the product's active ingredients and learn a few new words.
Choose a product that has a SPF of 30 or higher (assuring you of UVB protection) and that contains avobenzone (also called Parsol 1789) or a combination of titanium dioxide and zinc oxide.
That's the advice of Dr. Madhukar Pathak, dermatology research professor at Harvard Medical School and chairman of The Skin Cancer Foundation's Photobiology Committee.
Avobenzone has increased the range of UVA protection, he said, but it doesn't adequately protect against UVB; so, it's used in combination with UVB-absorbing chemicals.
Titanium dioxide and zinc oxide scatter and reflect both UVB and UVA, he said.
They're naturally occurring chemicals and, as long as they're free from impurities, they won't cause allergic reactions. That aspect makes them particularly good for children.
They're now available in micronized versions, which means they're processed into tiny particles and won't look like white goo on your nose.
Pathak's recommendation describes a good product.
He notes that an ideal product would have an SPF 30, UVB absorbers and avobenzone, in addition to titanium dioxide and zinc oxide in a micronized form.
Finding such a product might be difficult.
It would be nice if we didn't have to learn all those strange chemical names, and perhaps one day we won't. The American Academy of Dermatolog is trying to help.
A conference held Feb. 4 in Washington, and chaired by Lim, made specific proposals for standards that had to be met. He said the standards included testing methods and results that had to be achieved for a product to be labeled "broad spectrum."
Among the conference recommendations is that an increase in the SPF of a sunscreen must be accompanied by a proportional increase in UVA protection value.
It's up to the FDA to decide whether it will adopt these proposals, he said.
Experts interviewed wouldn't recommend specific products.
