Nail salon tool may cause DNA damage and cell mutation, research finds

By Kristen Rogers, CNN 

Radiation from nail dryers may damage DNA and cause cancer-causing mutations in human cells, a new study has found — and that might have you wondering whether your regular gel mani-pedi is worth the risk.

Some dermatologists say the findings, in a study published January 17 in the journal Nature Communications, aren't new when it comes to concerns about ultraviolet, or UV, light from any source. In fact, the results reaffirm the reason why some dermatologists have changed the way they get their gel manicures or have stopped getting them altogether.

"The findings contribute to data already published regarding the harmful effects of (ultraviolet) radiation and show direct cell death and damage to tissue that can lead to skin cancer," said Dr. Julia Curtis, an assistant professor of dermatology at the University of Utah, who wasn't involved in the study.

"Tanning beds are listed as carcinogenic and UV nail lamps are mini tanning beds for your nails in order to cure the gel nail," Curtis said.

A form of electromagnetic radiation, ultraviolet light has a wavelength ranging from 10 to 400 nanometers, according to the UCAR Center for Science Education.

Ultraviolet A light (315 to 400 nanometers), found in sunlight, penetrates the skin more deeply and is commonly used in UV nail dryers, which have become popular over the past decade. Tanning beds use 280 to 400 nanometers, while the spectrum used in nail dryers is 340 to 395 nanometers, according to a news release for the study.

"If you look at the way these devices are presented, they are marketed as safe, with nothing to be concerned about," said corresponding author Ludmil Alexandrov in the news release. "But to the best of our knowledge, no one has actually studied these devices and how they affect human cells at the molecular and cellular levels until now." Alexandrov holds dual titles as associate professor of bioengineering and cellular and molecular medicine at the University of California San Diego.

Researchers exposed cells from humans and mice to UV light, finding that a 20-minute session led to 20% to 30% of cells dying. Three consecutive 20-minute exposures made 65% to 70% of the exposed cells die. The remaining cells experienced mitochondrial and DNA damage, resulting in mutations with patterns that have been observed in skin cancer in humans.

The biggest limitation of the study is that exposing cell lines to UV light is different from conducting the study on living humans and animals, said dermatologist Dr. Julie Russak, founder of Russak Dermatology Clinic in New York City. Russak wasn't involved in the study.

"When we're doing it (irradiating) inside human hands, there's definitely a difference," Russak said. "Most of the UV irradiation is absorbed by the top layer of the skin. When you irradiate cells in the petri dish directly, that's slightly different. You don't have any protection from the skin, from corneocytes or the top layers. It's also very direct UVA irradiation."

But this study, taken together with previous evidence — such as case reports of people developing squamous cell carcinomas, the second most common form of skin cancer, in association with UVA dryers — means we should "definitely think harder about just exposing our hands and our fingers to UVA light without any protection," said Dr. Shari Lipner, an associate professor of clinical dermatology and director of the nail division at the NewYork-Presbyterian Hospital/Weill Cornell Medical Center. Lipner wasn't involved in the study.

Reducing your risk

If you're concerned about gel manicures but don't want to give them up, there are some precautions you can take to mitigate the risks.

"Apply broad spectrum sunblock that contains zinc and titanium around the nails, and wear UV gloves with the fingertips cut off when it is time to cure your nails," said Curtis, who doesn't get gel manicures. "I would recommend alternatives to gel nails, such as the new wraps that are available online." (Gel nail wraps or strips are stick-on gel nail products that don't always require being set by UV nail dryers.)

Some salons use LED lights, which "are thought to emit either no UV light or much, much lower amounts," Lipner said.

Lipner gets regular manicures — which typically last her seven to 10 days — not in an effort to avoid UV light but rather because she doesn't like the nail-thinning acetone soaking involved with gel manicures.

"Regular manicures are just dried in the air," she added. "Gel manicures have to be curated or sealed, and the polymers in the polish have to be activated, so that can only be done with the UVA lights."

If you have regularly gotten gel manicures, Lipner recommends seeing a board-certified dermatologist who can examine your skin for any skin cancer precursors and treat them before they become a serious problem. (Ultraviolet light can also age the skin, showing up as sunspots and wrinkles, she said.)

There isn't enough data for experts to weigh in on how often people can get gel manicures without putting themselves at risk, Lipner said. But Curtis recommended saving them for special occasions.

Russak doesn't get gel manicures very often but uses sunscreen and gloves when she does, she said. Applying serums rich in antioxidants, such as vitamin C, beforehand might also help, she added.

"As a dermatologist, I change gloves probably three, four times with just one patient. And with a regular nail polish, after three, four glove changes, the nail polish is gone," Russak added. "The gel manicure definitely has a much better longevity, but is it really worth the risk of photoaging and development of skin cancer? Probably not."

People with a history of skin cancers or who are more photosensitive due to fairer skin or albinism, medications or immunosuppression should be more careful about taking precautions, experts said. Whether or not you are at higher risk, however, the dermatologists CNN spoke with urged caution.

"Unfortunately, full protection is not possible, so my best recommendation is to avoid these dryers altogether," Zeichner said.