SUNDAY, July 13, 2008 (HealthDay News) -- Sunscreens are one of the most popular protections people use as the summer sun rises high and threatens to burn their skin with harmful ultraviolet rays.
Sunburns are not only painful, they can lead to skin cancer, the most prevalent form of cancer in the United States.
But, new research has led some to question the effectiveness of many sunscreens.
A recent study by the Environmental Working Group found that one in every eight name-brand sunscreens did not protect against ultraviolet A rays. These UVA rays have traditionally been linked to tanning, but doctors now know they can cause long-term damage and skin cancer. The SPF -- or sun protection factor -- rating currently placed on all sunscreens only reflects the lotion's effectiveness in blocking ultraviolet B rays.
As a result of such research, the U.S. Food and Drug Administration is the process of approving a new regulation that would set standards for testing and labeling sunscreens for UVA protection as well as for UVB.
The incidence of sunburns has increased in the United States, a sign the many people aren't using proper sun protection. A recent study by the U.S. Centers for Disease Control and Prevention found that sunburn rates increased from 31.8 percent to 33.7 percent from 1999 to 2004.
Sunburn damage to the skin is a direct cause of skin cancer, said Dr. Martin Weinstock, a professor of dermatology at Brown University Medical School.
"Most cancers in the United States are skin cancer, and incidences are rising, while the incidences of most other types of cancer are remaining stable or going down," Weinstock said. "The most important avoidable cause we know about is exposure to ultraviolet radiation."
Sunlight is composed of the visible light that we can see, and ultraviolet (UV) light that we can not. There are two types of UV light -- UVA and UVB. While UVA rays are responsible for tanning and UVB for sunburn, both can damage the skin and increase the risk of skin cancer.
Most skin cancers form in older people, on parts of their bodies that have experienced more exposure to the sun, or in people who have weakened immune systems.
The most deadly form of skin cancer is melanoma, which forms in the skin cells that make the pigment melanin -- often as a mole. The National Cancer Institute estimates there will be 62,480 new cases of melanoma in the United States in 2008, and about 8,420 deaths caused by the disease. By comparison, there will be more than 1 million new cases of non-melanoma skin cancers in 2008, with fewer than 1,000 deaths.
Experts recommend a multiple approach to protecting yourself against harmful rays.
"The American Cancer Society has a slogan -- 'Slip, Slop, Slap,' " Weinstock said. "Slip on a shirt, slop on some sunscreen, and slap on a hat."
But Kristan Markey, a research analyst with the Environmental Working Group, a nonprofit organization that works to protect public health and the environment, said the effectiveness of sunscreens isn't as strong as one might think.
"We found that most sunscreens are not effective in filtering out ultraviolet radiation or have problems with toxic hazards," Markey said.
Not only do many sunscreens fail to protect against UV radiation, but they also break down over normal usage and develop toxic components, the group's study found.
Markey noted that sunscreen makers also make claims that can't stand up to the light of day. For example, even sunscreens that boast "all-day protection" must be regularly reapplied to avoid skin damage, he said.
"You can't say 'all-day protection,' because the recommendation is you have to reapply every two hours," Markey said. "It's still very much the wild west in the industry."
The FDA's recommended new rules for sunscreens would assign a star rating system -- from one to four stars -- to gauge the lotions' effectiveness in blocking UVA rays. Ratings for UVA would be based on two tests, one to measure the sunscreen's ability to reduce the amount of UVA radiation passing through it, and a second to measure the product's ability to prevent tanning and potential long-term skin damage.
Given the mandatory approval process, any new labeling featuring the UVA ratings alongside the current SPF rating won't appear on store shelves until 2009 at the earliest.
Until then, Weinstock said people need to continue to check themselves often for changes in skin blemishes or moles, as a precaution.
"We do recommend that people do a thorough examination of their own skin once a month, top and bottom, front and back," he said. "If they see spots that are changing, ask for some advice from a medical professional.
"Early detection is important in the treatment of skin cancer, and it's right out there to see," he added.
To learn more about sunscreens, visit the American Academy of Dermatology.