UV: Ultraviolet radiation from the sun. UV radiation has been identified as a proven human carcinogen by the U.S. Department of Health and Human Services and the World Health Organization.
UVA: Long-wave rays from the sun. They play a major role in skin aging and wrinkling; contribute to and may even initiate the development of skin cancers.
UVB: Short-wave rays from the sun. They are the chief cause of skin reddening and sunburn. They play a key role in the development of skin cancer and contribute to tanning and skin aging.
SPF: Sun protection factor. The standard used to measure the effectiveness of sunscreens (measures UVB only).
UPF: Ultraviolet protection factor. The relatively new standard used to measure how much of the sun's UV radiation is absorbed by fabric (measures UVB and UVA).
Sunburns hurt. Melanoma can kill.
The sun's damaging ultraviolet rays are still being scrutinized by health experts, but a new wrinkle in sun protection is giving parents another line of defense in shielding their children from later skin damage.
In addition to sunscreens, with their well-known SPF ratings (for sun protection factor), certain clothing now comes with UPF ratings to measure the amount of ultraviolet protection.
Signal Mountain resident Renee Robinson Shoop, mother of two preschoolers, said that in addition to applying sunscreen she dresses her daughters in rash guard shirts and shorts as well as hats with UPF protection to minimize their sun exposure. Their swimsuits are rated UPF 50, blocking 98 percent of the sun's UV radiation. Regular swimwear can rate as low as UPF 5.
"I'm very concerned about protecting their skin from the sun," Shoop said. "It's not just burns - any tan is unhealthy and increases the risks of skin cancer later in life."
Katrina Craven of Chattanooga also insists that her young daughter, Jocelyn, wear UPF swimsuits.
"It's definitely important to me," she said. "All the medical literature I read and everything I hear from her pediatrician is to protect your children from early sun damage. The swimsuit is another layer of protection. It gives me piece of mind because she loves to be outside."
The UPF rating system measures the ultraviolet protection provided by the fabric. Unlike sunscreens' SPF ratings, which gauge ultraviolet-A rays only, UPF ratings measure both ultraviolet-A and ultraviolet-B rays. Both UVA and UVB radiation have been linked to skin aging, wrinkling and cancer, according to the Skin Cancer Foundation.
Michael Hubsmith, an executive vice president of Coolibar, said his company's sun protection clothing (made for children and adults) offers 98 percent protection against UVA and UVB rays for the life of the garment.
"We work with proprietary fabrics we've developed that use the main ingredient from broad-spectrum sunscreens, and they're incorporated into the fiber so they can never wash or wear off," Hubsmith said. "It's mostly titanium dioxide, but we also have a very successful zinc oxide fabric that we call 'ZnO Suntect.' If you look at sunscreen, you'll see the primary active ingredients are titanium dioxide or zinc oxide, or a combination of the two."
The UPF clothing is as easily maintained as regular clothing, according to Hubsmith. "Many of our UPF 50+ shirts are machine wash, tumble dry; and swimwear is machine wash, line dry," he said.
The Skin Cancer Foundation, Melanoma International Foundation and American Academy of Dermatology have endorsed Coolibar's apparel.
Another new product may make fun in the sun safer for children who get squirmy when sunscreen is applied. Sunbow sunscreens, available in a zinc oxide cream, spray or stick, go on in vivid hues - a SpongeBob SquarePants yellow and Dora the Explorer pink or blue - that fade into the skin.
"Children respond to the characters and then with the sunscreen being applied in colors and then 'magically' disappearing when rubbed in makes children stay still and not run away," said developer Andy Gershon.
Sunbow protects against UVA and UVB rays and has a bubblegum fragrance. The products have SPF 30 and 45 ratings, considered adequate protection, and are free of oxybenzone and octinoxate, which some studies suggest can be hazardous.