Lights Out on Suntans
Tanning by bulb as risky as by sun
FRIDAY, June 8, 2001 (HealthDayNews) -- If you're thinking about a few sessions in a tanning salon so you'll look great in that bikini -- be careful.
Though one session on a tanning bed doesn't heat the skin as much as the sun, it can damage your skin just as much, and may even pave the way for skin cancer, a new study says.
"I think that most people who attend tanning salons think they provide a safe, or at best, a safer tan than outside tanning," says lead study author Dr. S. Elizabeth Whitmore, associate professor of dermatology at Johns Hopkins University School.
But, ultraviolet rays from tanning bulbs produce the same damage as the sun to the outer skin layer and to your DNA, Whitmore says.
Federal law prohibit tanning salons from saying that indoor tanning is either "safe" or "safer than the sun," and only 21 states have laws governing tanning salons, a $2-billion industry in the United States. Radiation exposure in tanning salons cause 700 trips to the emergency rooms each year, says the Centers for Disease Control and Prevention (CDC).
The study exposed 11 people to 10 full-body tanning salon treatments over two weeks, with part of their buttocks covered as a control sample. During the final exposure, one-half of that covered area was exposed, to measure the effects of a one-time exposure.
The bulbs used in the study emitted 95 percent of ultraviolet A (UVA) light, which penetrates deep into the skin. The remaining 5 percent was ultraviolet B (UVB) light which affects the epidermis, or uppermost skin layer.
"Indoor tanning uses UVA radiation, which leads some in the industry to claim that indoor tanning is a safe alternative to outdoor tanning," Whitmore says. Even so, she says most salon bulbs still give off a certain amount of UVB radiation.
Tissue and blood samples taken after the single tanning session and after the final of the series of sessions revealed molecular DNA damage to the skin like that caused by the sun's rays. In fact, the amount of that DNA damage in the skin was about the same whether after just one exposure or after all 10 sessions. The samples also found that a protein that helps in the repair process showed up in all layers of the epidermis within a day of exposure, indicating damage is caused even by a short time under the bulbs.
"It's yet another marker or further evidence that the cell has been traumatized," says Whitmore.
Although the "DNA alteration is normally very efficiently repaired, the more times repair must occur, the greater the chance of inadequate repair," Whitmore says. If abnormal cells reproduce, they may lead to a visible skin cancer, she says.
Whitmore says the study used a higher dose of UV than what salons say they use. "The dose was likely more than should be recommended at suntan salons. However, we know that what is recommended and what is actually given in salons are often not the same."
Dr. Barbara Gilchrest, professor and chair of dermatology at Boston University School of Medicine says no tan is safe. "There's excellent evidence when you get a tan, you've damaged your DNA. The study results are exactly what I'd expect."
The study appears in last month's Journal of the American Academy of Dermatology.
What To Do
Be reasonable, says Gilchrest. "We all go outdoors. Wear sunscreen of an SPF 15 or higher on exposed areas." And if you go out, "do it early or late in the day, when the intensity of the damaging rays is much less."
For those who tan easily, Gilchrest says just don't overdo it. For people who "try and try and try and can't tan, you'll be in a lot of trouble 20 years later," she says.
The CDC lists steps you can take to prevent skin cancer.
And read about sunscreen agents and how to use them before venturing out.
For more HealthDay stories on the sun and skin cancer, click here.