Beauty and suffering are often thought to be intertwined. It is hard to have your cake and eat it too. In the quest for beauty, women (and men) have subjected themselves to toxic and potentially deadly practices, such as applying lead-based cosmetics to whiten their faces historically , or more recently, going to tanning beds and/or laying out in the sun for prolonged periods to get a “healthy glow.” As we have become increasingly health-conscious and vigilant, more and more beauty products and practices have come under scrutiny for their possible toxic effects. Most recently, a cousin of the tanning bed, the popular ultraviolet (UV) nail lamp, has become a topic of much controversy .
At first glance, the UV nail lamp seems like a miracle worker. It serves many purposes in the nail salon, such as its uses in: one, quickly drying UV-cured acrylic nails and traditional nail polish; two, activating special topcoats that help protect the nail; and three, the creation of gel nails, which are more durable than regular nail polish . However, like the tanning bed, it produces predominantly UV-A radiation, which is known to cause oxidative stress and free radical formation, leading to DNA damage .
The controversy over the potential carcinogenic effects of the UV nail lamp started with two case reports published in 2009 . These two reports described the development of non-melanoma skin cancers on the hands of two white women, who both had indoor occupations, little to moderate recreational UV exposures and no personal/family history of skin cancers. The major commonality shared by the two women was frequent visits to the nail salon – one with a 15-year history of twice monthly UV nail light exposure and the other with a history of eight episodes of UV nail light exposure within one year.
These two case reports prompted a lot of research into the amount of potential UV exposure from the UV nail lamp. The authors of the 2009 case reports argued that based on the amount of power produced by most nail lamps (4-54W), as compared to that of tanning beds (1200W or more), and the amount of body surface area exposed (2% in nail lamps vs. 100% in tanning beds), the amount of radiation per meter squared was actually comparable between UV nail lamps and tanning beds . Another study found that the amount of UV exposure per a typical nail session (lasting less than 10 minutes) totaled 15-22.5 joules per meters squared, which was comparable to that of the day-long recommended limit for outdoor workers and recreationalists (30 joules per meter squared over 8 hours) as per the International Commission on Non-Ionizing Radiation Protection .
However, other researchers have argued that the risk of skin cancer from UV lamps is minimal. In fact, UV light (especially narrowband UV-B) is frequently used in the treatment of common skin conditions such as psoriasis, vitiligo and atopic dermatitis . One study compared a UV nail lamp session’s UV dose to the UV dose of a single course of narrowband UV-B (NBUVB) used for phototherapy and found that more than 250 years of weekly UV nail sessions would be required in order to equal to exposure of that of one course of narrowband UV-B therapy . Since the risk of developing skin cancer from one course of NBUVB treatment was thought to be low , the authors of the study concluded that the risk of skin carcinogenesis from UV exposure from nail lamps must be low as well.
Another study attempted to quantify the actual risk of squamous cell carcinoma (SCC) from UV nail lamps . Based on complex calculations that took into account the ages of subjects and doses of UV light to which they were exposed, the study authors derived an SCC risk model, using data from six different studies on the incidence of SCC in different regions around the world, including Norway and the USA. They used this model to compare the risks of skin cancer from day-to-day sun exposure to that of UV nail lamps and from these calculated risks, they were able to determine the number of women who would need to be exposed to UV nail lamps in order for one woman to develop SCC on the dorsum of her hands, also known as the number needed to harm (NNH). Results showed that, depending on the age of the woman and the number of years of use of UV nail lamps, anywhere from tens to hundreds of thousands of women would need to be exposed to UV nail lamps in order for one woman to develop SCC on the dorsum of her hands.
Why is there such variety in the results from different studies? One group recently hypothesized that the range in different UV lamps available for commercial use might be the explanation . UV lamps differ in the number of bulbs, the power/wattage of each bulb and the brand of the light source, all of which may lead to differing amounts of UV-A radiation produced. This study measured the UV-A energy exposure in an average manicure visit from seventeen different UV lamps used in 16 nail salons, resulting in a range of 0 to 8 joules per centimeters squared, with a median of 5.1. The threshold value for DNA damage in UV-A irradiated skin cells is 60 joules per centimeters squared. Therefore, the number of visits needed for a customer to be exposed to this threshold value can range from 8 to 208, with a median of 11.8. The take-home point is that, depending on the UV nail lamp, the number of visits needed to confer DNA damage (i.e. the potential for carcinogenesis) to skin cells can vary greatly.
While different researchers may present conflicting evidence in regards to the degree of risk of skin cancer posed by UV nail lamps, they do mostly agree on recommending the use of either full spectrum sunscreens or UV-A blocking gloves to limit the exposure to only the nails [4, 8, 9]. Interestingly enough, the nail plate itself is very resistant to UV penetration – completely blocking the transmission of UV-B light and almost completely blocking UV-A light . Thus, even if the debate is ongoing, sunblock and/or UV-A blocking gloves may be a way for your patients to have their cake and eat it too.
Dr. Jennifer Ng completed her internal medicine residency at NYU Langone Medical Center
Peer Reviewed by Jo-Ann Latkowski, MD, Dermatology, NYU Langone Medical Center
Image courtesy of foxnews.com: Image – Skin Cancer: Are nail salon UV lamps a skin cancer risk? Foxnews.com. 1 May 2014. http://www.foxnews.com/health/2014/05/01/are-nail-salon-uv-lamps-skin-cancer-risk/
- Mapes D. Suffering for beauty has ancient roots: From lead eyeliner to mercury makeup, killer cosmetics over the decades. NBCNews.com. Web. Accessed June 1 2014. http://www.nbcnews.com/id/22546056/ns/health/t/suffering-beauty-has-ancient-roots/#.VbJaXaHD_1I
- Park A. 24 visits to the nail salon could trigger skin cancer. TIME.com. 30 Apr 2014. Web. Accessed June 1, 2014. http://time.com/82830/24-visits-to-the-nail-salon-could-trigger-skin-cancer/
- MacFarlane DF et al. Occurrence of Nonmelanoma Skin Cancers on the Hands After UV Nail Light Exposure. Arch Dermatol. 2009;145(4):447-449. doi:10.1001/archdermatol.2008.622.
- Curtis J et al. Acrylic nail curing UV lamps: High-intensity exposure warrants further research of skin cancer risk. Journal of the American Academy of Dermatology. 2013 Dec;69(6):1069-1070. Doi: http://dx.doi.org/10.1016/j.jaad.2013.08.032.
- Tanew A et al. Narrowband UV-B phototherapy vs photochemotherapy in the treatment of chronic plaque-type psoriasis: a paired comparison study. Arch Dermatol. 1999;135(5):519. http://archderm.jamanetwork.com/article.aspx?articleid=477846
- Markova A et al. Risk of Skin Cancer Associated with the Use of UV Nail Lamp. Journal of Investigative Dermatology. 2013;133: 1097–1099. doi:10.1038/jid.2012.440. Epub 6 December 2012.
- Diffey BL, Farr PM. The challenge of follow up in narrowband ultraviolet B phototherapy. Br J Dermatol. 2007;157:344–9. http://www.ncbi.nlm.nih.gov/pubmed/17553037
- Diffey BL. The risk of squamous cell carcinoma in women from exposure to UVA lamps used in cosmetic nail treatment. Br J Dermatol. 2012 Nov;167(5):1175-8. doi: 10.1111/j.1365-2133.2012.11107.x. Epub 2012 Oct 5.
- Shipp LR et al. Further Investigation Into the Risk of Skin Cancer Associated With the Use of UV Nail Lamps. JAMA Dermatol. Epub April 30, 2014. doi:10.1001/jamadermatol.2013.8740 http://archderm.jamanetwork.com/article.aspx?articleid=1862050
- Stern DK et al. UV-A and UV-B penetration of normal human cadaveric fingernail plate. Arch Dermatol. 2011 Apr;147(4):439-41. doi: 10.1001/archdermatol.2010.375. Epub 2010 Dec 20. http://archderm.jamanetwork.com/article.aspx?articleid=423480