It's routine for people all over the country: a nail tech paints your nails and motions for you to stick your hands into a UV lamp to dry.
The dryers have lamps or LEDs that emit UV or ultraviolet radiation, according to the U.S. Food and Drug Administration.
Researchers at the University of California San Diego wanted to better understand how the dryers and the radiation they emit impact the body, so they exposed human and mouse cells to UV rays from a gel polish lamp and analyzed how the UV rays changed them.
Maria Zhivagui, a postdoctoral researcher at the University of California San Diego who worked on the study, said the team wanted to address a public health concern.
The team found that radiation emitted by UV-nail polish dryers can permanently damage DNA but said future studies are needed to determine the relationship between the dryers and skin cancer.
The findings were published in the peer-reviewed journal Nature Communications this month.
Radiation from UV lamps can lead to mutations in DNA
While analyzing the cells after exposure to the lamp, the team noticed elevated levels of reactive oxygen species, or reactive molecules that are highly charged or stimulated.
The molecules can interact with proteins, mitochondria and other parts of human cells and prevent them from functioning properly, said Zhivagui, who worked on the study.
The team said the radiation emitted by UV nail polish dryers can lead to mutations in DNA. The radiation imprints on your DNA and each time your cell divides, the mutation will be present in the new cells. And cells divide constantly depending on the organ, Zhivagui said.
Maral Kibarian Skelsey is a board-certified dermatologist and director of the Dermatologic Surgery Center of Washington in Maryland.
She was not involved in the study but said UV dryers and indoor tanning devices emit UVA radiation that can go deep into the skin's cells.
She also stressed that this study didn't prove that the devices directly cause skin cancer.
It really depends on the patient's history with skin cancer, so those who have previously had it may want to reconsider using the dryers, as well as patients with weakened immune systems, Skelsey said.
What's different about this study?
There have recently been reports of a small number of melanoma and non-melanoma cases on the nail or on part of the hand, including a 52-year-old woman who, for 18 years, used UV nail lamps every 3 weeks and tanning beds weekly.
She developed squamous cell carcinoma, the second most common skin cancer worldwide, researchers published in 2019 in the peer-reviewed journal Case Reports in Dermatology.
"This patient's extensive UV nail lamp use coupled with UVA exposure from tanning beds may have put her at particular risk and exacerbated the effects of the nail lamp alone," the researchers said in the 2019 article.
Zhivagui, from the University of California San Diego, said the team's work is based solely on UVA radiation emitted by UV nail polish dryers.
"We are the first to study the molecular and cellular effect of these machines on mammalian cells and human cells," she told USA TODAY.
She also said the team used "state-of-the-art technology" such as DNA sequencing to see just how much the UV dryers damaged the cells.
She also said the team was not able to confirm that UV dryers may increase the risk of skin cancer and future studies are needed to determine this for sure. The team thinks it'll take at least 10 years to complete such studies.
According to the FDA, exposure to UV radiation can damage skin over time, causing premature wrinkles, age spots, and even skin cancer. However, the administration says nail curing lamps and UV dryers are low risk when used as directed by the label.
The FDA also said on its website that there have been no reports of burns or skin cancer due to the lamps.
Limitations of the study
Zhivagui said one of the study's limitations is the lack of previous epidemiological research on the topic to help better understand the risk of cancer when using these lamps.
Skelsey, the board-certified dermatologist, said one of the study's limitations is that it did not involve actual human beings, nor did it look at the long-term impact of using UV nail dryers to see whether people developed skin cancer.
"It doesn't perfectly replicate what happens in the human body," Skelsey told USA TODAY. "It's not clear how much damage is actually going to occur in a human being ... And lastly, the experimental design doesn't account for the fact that there's another layer of skin ... it's kind of our protective layer on the outside."
So are UV lamps safe or not?
Zhivagui recommends limiting exposure and following Food and Drug Administration guidelines.
Make sure your hands aren't under the lamps longer than the FDA recommends.
"In general, you should not use these devices for more than 10 minutes per hand, per session," the agency recommends on its website.
Skelsey said the FDA clearly hasn't taken them off the market because there hasn't been enough evidence to show they aren't safe.
"Is it unsafe to walk to your nail salon and get exposed to the sun?" she asked. "I would caution teenagers and young adults about the risks because they're going to have a lot of cumulative exposure if they're doing this every two weeks."
And if you're worried or notice any changes on your hands, around your nails or on your body, get evaluated by a dermatologist, she said.
Lastly, what you do regularly in other parts of your life will have a bigger impact on your body.
"Wearing a broad brim hat, long sleeves and protective clothing," Skelsey said. "Consider the UV shields in your car ... Those all diminish your cumulative exposure."
Saleen Martin is a reporter on USA TODAY's NOW team. She is from Norfolk, Virginia - the 757 - and loves all things horror, witches, Christmas, and food. Follow her on Twitter at @Saleen_Martin or email her at firstname.lastname@example.org.
This article originally appeared on USA TODAY: UV nail lamps can change your DNA, cancer questions remain, study says