An anonymous reader quotes a report from Phys.Org: The ultraviolet nail polish drying devices used to cure gel manicures may pose more of a public health concern than previously thought. Researchers at the University of California San Diego have studied these ultraviolet (UV) light emitting devices, and found that their use leads to cell death and cancer-causing mutations in human cells. The devices are a common fixture in nail salons, and generally use a particular spectrum of UV light (340-395nm) to cure the chemicals used in gel manicures. While tanning beds use a different spectrum of UV light (280-400nm) that studies have conclusively proven to be carcinogenic, the spectrum used in the nail dryers has not been well studied.
Using three different cell lines — adult human skin keratinocytes, human foreskin fibroblasts, and mouse embryonic fibroblasts — the researchers found that the use of these UV emitting devices for just one 20-minute session led to between 20 and 30 percent cell death, while three consecutive 20-minute exposures caused between 65 and 70 percent of the exposed cells to die. Exposure to the UV light also caused mitochondrial and DNA damage in the remaining cells and resulted in mutations with patterns that can be observed in skin cancer in humans. […] The researchers caution that while the results show the harmful effects of the repeated use of these devices on human cells, a long-term epidemiological study would be required before stating conclusively that using these machines leads to an increased risk of skin cancers. However, the results of the study were clear: The chronic use of these nail polish drying machines is damaging to human cells. “We saw multiple things: first, we saw that DNA gets damaged,” said Ludmil Alexandrov, a professor of bioengineering as well as cellular and molecular medicine at UC San Diego, and corresponding author of the study published in Nature Communications. “We also saw that some of the DNA damage does not get repaired over time, and it does lead to mutations after every exposure with a UV-nail polish dryer. Lastly, we saw that exposure may cause mitochondrial dysfunction, which may also result in additional mutations. We looked at patients with skin cancers, and we see the exact same patterns of mutations in these patients that were seen in the irradiated cells.”
“Our experimental results and the prior evidence strongly suggest that radiation emitted by UV-nail polish dryers may cause cancers of the hand and that UV-nail polish dryers, similar to tanning beds, may increase the risk of early-onset skin cancer,” add the researchers. “Nevertheless, future large-scale epidemiological studies are warranted to accurately quantify the risk for skin cancer of the hand in people regularly using UV-nail polish dryers. It is likely that such studies will take at least a decade to complete and to subsequently inform the general public.”