UV rays important to life, but also dangerous

Here comes the sun, Here comes the sun, And I say it's all right. ..."

Health advocates might tell the Beatles they needed to reword the pop tune that welcomes the summer.

Sun is all right, in moderation.

Sun makes ultraviolet rays, commonly called UV. And as much as we love our faces warmed by the sun, too much UV isn't all right - for our faces, eyes, arms, legs, hands, torsos, feet, even our toes.

"The No. 1 cause of premature aging and skin cancer is ultraviolet exposure," said Dr. J. Hunter Phillips III, a Biloxi, Miss., dermatologist. "That's the word I try to get out. Some listen; some don't. It's like smoking.

"I'd say that in the last decade, exposure to excessive UV has at least quadrupled due to more tanning beds. I also find the younger ones don't listen as much. They think they're invincible and there's a lot of peer pressure for a tan. The American Academy of Dermatology is trying to introduce legislation for tanning beds that would include informed consent and parental consent.

"People need to be aware that what they are doing now could be the cause later in life for skin problems and skin cancer."

Phillips and other dermatologists preach sunscreen, sunblock, protective clothing, hats, sunglasses and limited exposure.

"I'm a realist. You don't tell people not to go outside. I like being outside myself," Phillips said. "But everything in moderation. Go out early in the morning or late in the afternoon."

An Environmental Protection Agency Web page with a UV Index Forecast allows many Americans to see the ultraviolet potential for their communities. Recently, the Mississippi Coast was advised on the site developed by EPA and the National Weather Service (www.epa.gov/sunwise/uvindex.html) that:

"Protection against sun damage is needed. If you need to be outside during midday hours between 10 a.m. and 4 p.m., take steps to reduce sun exposure. A shirt, hat and sunscreen are a must, and be sure you seek shade. Beachgoers should know that white sand and other bright surfaces reflect UV and can double UV exposure."

If not computer savvy, you're still barraged with sun advice from advertisements and just about any medical professional.

Those with freckles, fair skin, or who are salon tanners or who are old-fashioned sun worshippers are duly warned. Beware of Mr. Sun and his ultraviolet rays.

We are a UV-aware society but whether we follow the advice is another story.

More than 10,000 Americans die each year from melanoma, and the cases get worse as the population's exposure to UV radiation appears to increase. The American Cancer Society expects 62,190 melanoma cases this year.

There are three types of UV: UVA (penetrates skin deeper and causes premature aging, cancer), UVB (causes sunburns and repeated exposure can cause cancer) and UVC (usually well filtered by ozone).

Layers of ozone shield the Earth from much of the sun's harmful UV radiation, but scientists say ozone depletion, along with seasonal and weather variations, cause different amounts of UV to reach the Earth at any given time.

And UV isn't all bad. Small amounts are essential for the production of vitamin D, although overexposure may result in acute and chronic, sometimes deadly health problems. As in so much we do for our health, it's a balancing act, one not always understood by the younger among us who put perceived attractiveness above sun warnings.

The World Health Organization jumped on the bandwagon this year when it advised no person younger than 18 should use a tanning bed. In reporting that exposure to UV, either naturally from the sun or from artificial sources such as sunlamps, is a known risk factor for skin cancer, WHO cited that one in three cancers diagnosed worldwide is a skin cancer.

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3 TYPES OF UV SUN RAYS:

UVA

This one penetrates more deeply into the skin and is responsible for contributing to photodamage and wrinkling of the skin, premature aging and skin cancer. UVA is prevalent in tanning parlors where tanning devices can emit two to five times more UVA than natural sunlight.

UVB

These rays are shorter but stronger. UVB primarily affects the skin's outer layers and is thought to be the primary cause of sunburn, skin aging and skin cancer. UVB rays tend to be more intense during the summer, at higher altitudes, and at locales closer to the equator. Repeated exposure to UVB over the course of one's life can cause skin cancer and alter the immune system.

UVC

These are the strongest, most dangerous rays. However, little attention is given to UVC rays as they are normally filtered by the ozone layer and do not reach the Earth.