UV “nail” lamps linked to a risk of skin cancer?

THE UV lamps used during a manicure to dry and set semi-permanent nail polish or to consolidate the application of gel nails emit type A (UVA) UV rays, which penetrate deep into the skin, which would promote aging but above all the development of skin cancer, reports theAcademy of Medicine in a press release dated April 28, 2023. The favoring role of “nail” UV lamps in the induction of these skin cancers has already been mentioned in 2009 and UVA rays are also classified as “carcinogenic” by the International Agency for Research on Cancer. Indeed, these rays are known to damage the DNA of skin cells by producing free radicals, which induce the appearance of cancer-causing mutations in these cells.

What are the risk factors?

In the context of the use of semi-permanent nail polish, the risk seems above all linked to 3 factors:

• The young age of onset of use (on average 20 years)
• The close frequency of exposures, (average of 5 to 6 times per yearor even more with the development of lamps at home)
• The exhibition for several years. “The cumulative effect of UVA exposures represents the major risk. It can be aggravated by the terrain (clear skin, immunosuppression)“, describes the Academy of Medicine.

What is the risk of skin cancer with UV lamps?

For the year 2022, a summary of the side effects induced by semi-permanent varnishes listed three types, all in women :

• Allergic skin reactions (66 cases, 70.5% of cases)
• Mechanical damage to the nails (23 cases, 26.1% of cases)
• Three cases of induced squamous cell carcinoma-type skin cancer (3.4% of cases)

These carcinogenic effects have also been demonstrated by researchers at the University of California, San Diego in a study published in the journal Nature on January 17, 2023. To assess the toxic effect of irradiation with a UV lamp, three types of cells were required. Mouse embryonic fibroblasts (connective tissue cells: MEF on right graph), human foreskin fibroblasts (HFF on right graph) and adult human epidermal keratinocytes (skin cells: HEKa on right graph ) were exposed in several distinct conditions. Each cell line was irradiated one, two or three times, with a duration of each exposure varying between 0 and 20 minutes (in most manicures, the nails are irradiated for up to 10 minutes in total with a UV lamp). At the end of the irradiations, the researchers demonstrated that the radiation emitted by the UV nail polish dryers had both damaged DNA and engraved permanent mutations in the genomes of connective tissue cells and of the skin (epidermal keratinocytes, in other words of the superficial layer of the skin). The same mechanism than that seen in human skin cancer.

► A single 20-minute irradiation caused the cell death of 20 to 30%

► Three consecutive 20-minute exhibitions (one 20-minute session per day for 3 days) caused between 65% and 70% cell death

“When we first started researching this, we noticed a number of reports in medical journals that people who get gel manicures very frequently – such as pageant contestants and beauticians – had reported cases of cancer in the fingerssuggesting that it could be something that causes this type of cancer“, says Ludmil Alexandrov, professor of bioengineering and cellular and molecular medicine at the University of San Diego, who participated in the study. While these preliminary results may be concerning, a long-term epidemiological study is necessary before asserting that the use of these machines leads to an increased risk of skin cancer.

What precautions to take?

In this context and as a precautionary measure, the Academy of Medicine has issued several recommendations:

► Apply sunscreen with indicated UVA protection, about 20 minutes before the exhibition from hands to UV/LED lamps;

► Establish a census of the number of UV/LED devices sold each year, in order to be able to estimate the evolution of the market and to attach to each lamp purchased a written message of alert and recommendations;

► Develop information campaigns for the general public and the professionals concerned, emphasizing the risk associated with continuous application of semi-permanent varnishes throughout the year, in particular among people with a clear phototype ► Carry out epidemiological studies to assess the risk of skin carcinoma induced by the frequent repetition of this type of irradiation over a long period.

Sources:

– DNA damage and somatic mutations in mammalian cells after irradiation with a nail polish dryer, Revue Nature, January 17, 2023.

– “Shiny” nails, but not without risk! Academy of Medicine April 28, 2023