Prized for their resistance and their shiny finish, gel manicures have for several years established themselves in the beauty habits of women – and men – around the world. But an American study calls into question their safety, and more particularly that of the UV lamps necessary for this technique, which could eventually damage the DNA and cause mutations likely to increase the risk of skin cancer.
The application of a gel varnish, or a semi-permanent, requires the use of UV lamps which allow the material to harden and dry quickly, while giving it a glossy appearance that is not found in classic nail polishes. Strengths that have propelled these two techniques to the rank of beauty must-haves. It remains that the UV lamps used for these services, similar to very small tanning beds, have not to date been the subject of scientific studies demonstrating the safe and harmless nature attributed to them. Unlike tanning booths, which produce – like nail lamps, although more intensely and with a different spectrum – mainly UVA rays, and whose increased risk of developing skin cancer has now been proven.
After discovering cases of skin cancer on the hands in two healthy women who regularly had recourse to this type of manicure, a team of American researchers from the universities of California in San Diego and Pittsburgh decided to take an interest the impact of these UV lamps on human cells at the molecular and cellular levels. Published in the journal Nature Communications, their research suggests that frequent, long-term exposure to these lamps could damage DNA, leading to cellular mutations similar to those seen in skin cancer patients.
20 to 30% of cells destroyed in 20 minutes
To reach these conclusions, the researchers exposed human and animal cells – mouse embryonic fibroblasts, human foreskin fibroblasts, and adult human keratinocytes – to these UV lamps under various conditions. “Each primary cell line was irradiated one, two or three times, with the duration of each exposure ranging from 0 to 20 minutes. Cell viability was measured 48 hours after the last irradiation, with each condition being repeated at least three times” , say the authors of the study.
At the end of their work, the researchers observed cytotoxicity induced by the UV radiation emitted by the nail lamps. They point out that a single 20-minute irradiation caused 20-30% cell death, while three consecutive 20-minute exposures resulted in 65-70% cell destruction. The scientists also came to the conclusion that frequent, long-term exposure could lead to mutations similar to those observed in patients with skin cancer.
Results that now require a more in-depth epidemiological study before sounding the alarm on these devices which, it should be noted, are not used in the same way in each region of the world. “It is likely that such studies will take at least a decade to complete and then inform the general public,” say the American researchers.
Less than 10 minutes in institute
If this study is by no means insignificant, it is important to specify that the work does not necessarily reflect the real conditions of a gel manicure, whether it is carried out at home or in an institute. For such a service, the drying time after each coat of material – a base, two coats of varnish, a top coat – varies on average between 30 seconds and 120 seconds depending on the type of lamp used, and it can even be less in some institutes. Which means that at the very most, the hands are supposed to spend 8 minutes under the lamp. A time much lower than that experienced by the researchers. This does not mean that the risk is not real, far from it, but that studies must indeed come to support this initial research.
Referring to a study carried out in 2013, the Food and Drug Administration (FDA), the American health agency, evokes for its part “a low risk when [ces lampes] are used according to label instructions”. Concluding: “To date, the FDA has not received any reports of burns or skin cancers attributed to these lamps”; the report however dates from 2017.
Just 10 years ago, the Skin Cancer Foundation also alerted the public to the potential danger of these lamps. “Although studies have shown that the risk of skin cancer associated with UV-emitting nail lamps for gel manicures is very low, it is not insignificant,” explained dermatologist Elizabeth K. Hale at the time. affiliated with the prevention organization. Which recommends since applying a broad-spectrum sunscreen to the hands about twenty minutes before exposing them to these UV lamps, or specific gloves leaving only the nails exposed. However, he specifies: “If you are getting a manicure, the safest thing is to let your nails air dry”.