For more than a decade, researchers have suspected that ultraviolet nail dryers used for gel manicures might be associated with an increased risk of skin cancer if used routinely. Dryers expose people to ultraviolet A (UVA) radiation, which is known to cause skin cancer from other sources, such as sun exposure and tanning beds.

A study published last week offers new evidence: It discovered that radiation from UV nail dryers can damage DNA and cause permanent mutations in human cells, which in turn is linked to cancer risk.

Such cell damage «is just one step on the road to cancer,» said Dr. Julia Curtis, an assistant professor in the department of dermatology at the University of Utah, who was not involved in the new research.

However, the study did not look at real people: the researchers exposed cells derived from humans and mice to ultraviolet light from nail dryers. They observed that after 20 minutes, 20% to 30% of the cells had died. After three consecutive 20-minute sessions, 65-70% of the cells had died.

Previous studies have linked only a few cases of skin cancer to gel manicures. A analysis 2020 identified two women in the US who developed melanoma on the back of their hands between 2007 and 2016. Both had had gel manicures for years. Overall, though, the researchers found that this type of manicure, which involves applying gel polish that then needs to be set under UV lamps, had little or no association with cancer.

«At this point, I would recommend or advise people to weigh the risk,» said one of the new study’s authors, Maria Zhivagui, a postdoctoral researcher at the University of California, San Diego. «Understand what this is doing. There is damage at the DNA level. We don’t know if it’s carcinogenic.»

Scientists will need to study the effects of UV nail dryers on real humans before they can draw any definitive conclusions about cancer risk, he added. Both Zhivagui and Curtis said the process could take another 10 years, given the slow pace of the investigation.

«I would say that UV nail lamps didn’t really become popular until around the 2000s, so doing that cause and effect can be very difficult,» Curtis said.

Even so, Curtis and Zhivagui said that in their own lives they never get manicures that require UV nail dryers.

«You won’t find a dermatologist who doesn’t say that UVA rays age us and increase our risk of skin cancer,» said Dr. Loretta Davis, chair of the department of dermatology at Augusta University in Georgia. «So anything deliberately done with that type of device will contribute.»

Davis said she doesn’t get a manicure, but she would be concerned about the aging effects of UVA radiation if she did.

The harmful effects of UV rays accumulate over time, and Davis himself research has suggested that the more frequently people get their manicures under UV nail lamps, the greater the risk of damage.

Using a UV nail dryer every two weeks is «probably too much,» she said.

«If you’re going to do this before a wedding and you want to feel special, sure,» Davis added. «But doing it routinely, no, I wouldn’t do that.»

Studies have yet to determine if there is a safe level of UVA exposure in the context of manicures or exactly how much might pose a health risk.

Zhivagui’s previous research has suggested that putting acrylic nails under ultraviolet light every three weeks for a year might produce more intense UVA radiation than sunlight during that time.

All three dermatologists agreed that wearing fingerless gloves when using a UV nail dryer and applying a broad-spectrum waterproof sunscreen that has at least 50 SPF before a nail appointment might offer some protection.

They also said that people who are older, have lighter skin, or take medications that make them more sensitive to light, such as certain blood pressure medications, should be more careful.

Davis said some people may decide that UV radiation exposure from gel manicures is simply not worth the risk, given how much we still don’t know.

«People don’t want to know five years later that they were doing something risky and could have taken precautions to protect their hands,» he said.