So what's the harm if the damage has been done?

By Times staff
© St. Petersburg Times
published April 23, 2002

Scientists believe ultraviolet rays inflict a "double whammy" to the skin's DNA. In studies done with mice, and exposures equivalent to a day at the beach, researchers at Yale University School of Medicine found UV harms a mechanism that repairs cell damage. The mechanism normally directs damaged cells to commit "suicide" -- the reason skin peels after a sunburn. When it malfunctions, the bad cells remain and malignancies can occur.

You're going to nag me about my picnic basket, too?

A high-fat diet has been implicated in colon and breast cancers and, more recently, in an increased likelihood of skin cancer after exposure to UV rays. Researchers at the Veterans Affairs Medical Center in Houston found a low-fat diet decreased actinic keratosis, a precancerous thickening of the skin. The patients with a high-fat diet had nearly five times the risk of actinic keratosis during the two-year study. High fat was defined as 35 to 40 percent of calories from fat, or about the same percentage consumed by most Americans.

What's with the weather guy's UV Index?

The National Weather Service provides a daily measure of ultraviolet exposure. The UV Index number indicates the amount of UV radiation reaching the earth's surface during one hour around noon. When the weather guy says the UV number is 5 or higher (on a scale of 0 to 10), be extra vigilant. And remember, exposure doesn't just come from above: Ultraviolet rays bounce off sand, water and even concrete.

Source: Food and Drug Administration

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