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.