WASHINGTON Another sun-baked summer day, and at the suburban pool, there was no paucity of sun worshippers. Among them: Lori Mininger, 23, who admitted she knew better. She knows about the risks of skin cancer; knows about the A-B-C-D signs of melanoma, the most dangerous kind of skin cancer. Yet there she was, stretched out on her striped towel for a few more hours of soaking up rays.

Without even a dot of sunscreen. Her skin, tan and abundant with freckles, was glowing. “I know I should put some on,” Mininger, just a couple of weeks past a burn, confessed with a sheepish smile.

Dermatologists say and studies confirm that Mininger has plenty of company, especially among teen-agers and twenty-somethings. With this crowd especially, warnings about the deleterious effects of exposure to ultraviolet rays still pale in comparison to images of bronzed bodies.

A study several years ago by the American Cancer Society concluded that more than two-thirds of people ages 11 to 18 took no precautions in the sun. Another found that more than seven in 10 youths had been sunburned during the summer.

Melanoma’s symptoms have long been relayed via user-friendly alphabet clues: A (asymmetrical areas of a mole, lesion or skin growth), B (irregular borders), C (color variation, especially darkening browns to black) and D (diameter bigger than that of a pencil eraser).

“We really have lots of work to be done on prevention,” said Vilma Cokkinides, program director of risk factor surveillance for the American Cancer Society. “Unfortunately, we haven't really changed that social mindset.”

Most skin cancer is the result of the accumulated insult of sun exposure over time, with severe sunburning early in life being a key risk factor. More than 59,500 new cases of melanoma are projected this year, compared with 38,300 a decade ago. The National Institutes of Health reports that melanoma is the leading cause of cancer death among women ages 25 to 30.

“We are seeing lots of young people with melanoma,” said Michael Todd, a dermatologist with the Skin Cancer Center of Northern Virginia. The tragedy, he and others said, is that skin cancer is so preventable and that melanoma, which accounts for about three-fourths of deaths, is highly curable if detected early. “If caught late,” Todd said, “it’s lethal.”

If there is progress, it’s among preadolescents. They are growing up with increasing messages about skin cancer in schools, with parents who are insisting on sunscreen (even if they don’t wear any themselves).