Sun worshippers beware.

Dermatologists, who for years have warned about sunshine's ill cosmetic effects on the skin, now say the incidence of melanoma cancer in the United States is doubling every 10 years. The numbers are even higher in Utah.The culprit: the bright, beautiful sun.

"It's predicted that in 1990 some 30,000 people will die of melanoma; it's a major health threat," said Dr. Laurence Meyer, an internist, geneticist and assistant professor of medicine in the University of Utah's department of dermatology. "This is largely because people have been spending more time in the sun because it's fashionable.

"If we could reduce the time people spend in the sun, we could reduce the incidence by 80 percent - saving 80 percent of those lives."

Scientists say that 40 or 50 years ago, cancer caused by the sun was rarer.

"Ironically, (back then) it was considered very low-class to have a tan; it was something laborers who worked outside had," Meyer said. "The aristocrats believed you should be able to see the veins through the skin."

Thus the term "blue blood" was coined.

"But with the rise of Hollywood, being tan became more fashionable," the physician said. "As people got more leisure time, it was deemed healthy to have a tan."

Wishful thinking, he said.

"The down side is that the sun causes permanent changes to the skin that are cumulative," he said. "The tanner a person becomes, the worse her/his skin looks down the road."

Extensive exposure to the sun causes wrinkly or lizard-like skin. Age or liver spots, freckles and white patches begin appearing and the skin becomes thin, causing it to rip and bruise more easily.

Long-term tanning also causes squamous cell cancer and basal cell cancer (the most common cancer) and even worse, melanoma cancer - which is fatal in about 40 percent of the cases.

The physician said there is no reason to believe that the ultraviolet lights used in tanning salons are any better for the skin than harsh sunlight.

Meyer's advice: Get less sun than you do now. Especially avoid getting burned. People who report 10 or 20 sunburns as children are several times more likely to get melanoma as adults.

"There is some slight truth to the argument that having a suntan is more likely to prevent a sunburn," he said. "But most people are much more tan than they need to be."

Meyer said dozens of modern easy-to-use, colorless, odorless sunscreens are on the market, and every household should have at least one bottle with an SPF (sun protection factor) rating of 15 or greater.

If a person has a reaction to one sunscreen, he can find another.

Meyer urges parents to be especially rigorous about applying sunscreen on young children routinely each morning during the summer.

Some other tips from the doctor: Wear protective clothing and sunglasses that protect from ultraviolet rays, and be particularly cautious about the sun during mid-day and around bodies of water. People taking prescription medications should ask if the drug could cause a special sensitivity to the sun.

Most important, he urged people to be aware of cancer symptoms.

Melanoma, he said, can be cured if discovered and removed in its early stages. But once the mole-like lesion becomes enlarged, removing it doesn't always cure the cancer.

"People who have abnormal moles that are asymmetric, more than one color, or larger than a quarter of an inch (the size of a pencil eraser) should have them evaluated - especially if they itch, bleed, ooze or are changing rapidly," he said. "These are the danger signs for melanoma."