Spring break is just days away. Time to pack up your bathing suits and beach towels and make a run for the sun.

And don't forget the sunscreen.

Tanning is becoming more risky every year because of ozone depletion, said William Brune, associate professor of meteorology. The ozone level, which protects the Earth's surface from the sun's intense ultraviolet light over the Northern Hemisphere, is 3 percent less than a decade ago, Brune said.

"That's a small number but it's a lot," he said. "That's a possible 6 to 7 percent increase in the risk of skin cancer. As the ozone decreases, the risks and dangers increase."

Because of the drop in ozone levels, spring break tanners could be exposed to more ultraviolet rays than average, Brune said. The ozone level varies daily in any particular place because of the motion of air masses, Brune said, adding that variation could be as high as 25 percent.

"You can take it as a given that anywhere you go, there's going to be less ozone than there was a decade ago," he said.

The biggest health risk of tanning is skin cancer, said State College dermatologist Mark Kozminsky. The sun's rays also damage the elastic fibers in the skin, causing a sagging, wrinkling, weather-beaten look after years of tanning.

Sunscreens -- which work by absorbing, reflecting or scattering the ultraviolet rays hitting the skin -- are somewhat successful protection, Kozminsky said.

Any sunscreen with a sun protection factor under 15 is ineffective, Kozminsky said, adding that sunscreen quality is better than ever.

Tanning is part of a social stigma, Kozminsky said. In the 18th and 19th centuries, tan skin was associated with the lower class who had to work outdoors for a living. But this changed after the Industrial Revolution when the lower class began to work indoors, he said, adding that the well-to-do were then the tan ones, as they had leisure time to spend outdoors.

"Tanning became a socially positive thing," Kozminsky said. "Now things are changing again because everybody knows that laying out in the sun is a bad thing."

People lie in the sun because they say being tan makes them look better, Kozminsky said, adding that this makes them feel better about themselves.

If people decide to continue tanning despite the health risks, they should at least take some safety precautions, Kozminsky said.

Here are some safety tips for sun worshipers:

-- Always wear sunscreen. Choose an SPF according to your skin type. It is best to apply sunscreen 30 minutes before exposure. Reapply after swimming. Be sure to protect your lips with SPF lip balm.

-- Wear sunglasses.

-- Bring some sort of shading device to the beach. Umbrellas and large hats with brims work well.

-- The sun's rays are most intense from 10 a.m. to 2 p.m. Ultraviolet rays do not always feel hot, so you can burn even on cloudy days. A sunburn generally does not appear until about two hours after exposure so you may not know you are burning.

-- Avoid overexposure.