We investigated whether the concerns of skin cancer caused by UV lamps used for curing gel nail polish manicures are justified. Many people avoid these manicures due to their fear of potential harm.”
Beauty salons have gained popularity for long-lasting nail polish services, specifically gel nail polish. This material consists of a mixture of gel and pigment, which is cured using UV or LED lamps. It is important to note that “shellac” is a product of CND, the first coating to appear on the market in 2009. Gel nail extensions, on the other hand, require a UV lamp, and they differ from gel nail polish. A photosensitizer component, such as benzoyl peroxide, is present in these products. When exposed to light, the liquid methacrylate transforms into a solid polymer within seconds.
In January 2023, many global media outlets reported on a new study conducted by scientists from the University of California, San Diego and the University of Pittsburgh in the United States. The study investigated the potential link between skin cancer and the use of nail lamps.
The researchers exposed fibroblasts from mouse embryos, as well as dermal and epidermal keratinocytes from humans, to UV lamps commonly used in nail salons. The cells were exposed to the lamps for up to 20 minutes, and some were irradiated one to three times. The cells that were irradiated three times were exposed over one day with a one-hour break, while others were exposed once for three days.
The study found that even a single 20-minute exposure resulted in the death of 20-30% of any type of cell, while triple exposure led to the death of 65-70% of cells.
Lyudmil Alexandrov, a co-author of the study, mentioned that exposing cells to nail lamps can result in DNA damage. Additionally, some of the damage might not be repaired over time, leading to a continued mutation of the DNA molecule with each subsequent exposure to the lamp. The researchers have also noticed that such exposure can cause dysfunction of mitochondria, which play a crucial role in breaking down nutrients and supporting cell function, resulting in additional mutations. These mutations resemble those found in patients with skin cancer.
UV lamps used in salons have raised concerns about their potential harm, even though they have become widely used in manicures. While ultraviolet radiation can be carcinogenic to humans, the US Food and Drug Administration (FDA) considers gel-lamp devices to be relatively safe when used according to the instructions, typically no more than ten minutes per hand per session.
According to the Cancer Council Australia, there are no serious studies that establish a link between the use of ultraviolet lamps during a manicure and the development of cancer. Experts also mention that the radiation levels emitted by such lamps are typically low, and the exposure time is brief. The Skin Cancer Foundation (USA) notes that even the most intensive lamps used in manicures emit much less radiation than those used in tanning salons.
Furthermore, the authors of the recent study mentioned in many media outlets point out that the results of their cell experiment may not fully represent real human skin because there is a layer of dead skin that protects the cells from ultraviolet radiation. As a result, there is no reason to believe that a single 20-minute session of manicure with the use of a lamp will result in the death of 30% of the skin cells on the hand.
In vitro studies, which involve examining cells or tissues outside of a living organism, allow for a detailed analysis without the interference of external factors. However, unlike in vivo studies conducted on living organisms, they do not provide a complete understanding of how the entire organism may react since they cannot replicate the conditions within the organism. Therefore, it is important to approach the results of in vitro tests with caution as they may not necessarily be valid for a living organism.
There exist various types of skin cancer, determined by the specific cells that are affected. The most widespread categories include:
- Basal cell carcinoma, which is characterized by the uncontrolled growth of basal cells found in the top layer of the skin (epidermis). This type is the most commonly occurring skin cancer.
- Squamous cell carcinoma, which is a cancerous tumor that develops from epidermal keratinocytes and can spread into the dermis.
- Melanoma, which arises from melanocytes, skin cells that synthesize melanin, the pigment that imparts color to the skin. Among these three types, melanoma is the most perilous.
In 2012, specialists at the Institute of Cellular Medicine at Newcastle University (UK) created a mathematical model to determine how many women would develop squamous cell skin cancer on the back of their hand from using UV lamps for manicures every two to three weeks. The model considered factors such as age, frequency of UV exposure, and compared the risk of developing cancer from UV lamps to that of sun exposure.
According to the researchers, regularly using UV lamps for manicures would only result in one case of the skin cancer of interest in tens or even hundreds of thousands of women. Thus, they concluded that the risk is very low and “likely acceptable for most women.”
Rapid Precision Testing Laboratories’ American experts utilized spectral weighing to compare the risks of developing non-melanoma skin cancer due to the use of manicure lamps and exposure to sunlight (when the sun is directly overhead and when rays fall at an angle) according to the method of the International Commission on Illumination. They studied six different models of lamps with varying power and found that the risk from overhead sunlight is 11-46 times higher (depending on the device model) and from light that falls on the skin at an angle, it is 3-12 times higher than from manicure lamps, with equivalent exposure time.
In 2020, dermatologists from the US reviewed medical literature to analyze the relationship between using UV lamps during manicures and the risk of skin cancer. They focused on patients under 40 years old and looked for cases of non-melanoma and melanoma skin cancers on the back of the hands and nail matrix. The researchers also analyzed melanoma incidence rates in people under 39 years old from 1975 to 2016 and trends in melanoma incidence in patients of all ages from 2007 to 2016 using the SEER (The Surveillance, Epidemiology, and End Results) program. The results of the review showed that there were no registered cases where patients under 40 who regularly did gel manicures developed skin cancer on the back of their hands or nail matrix. Moreover, there were no significant changes in melanoma incidence rates among patients under 65 years old. The dermatologists concluded that using UV lamps during manicures carries a practically absent carcinogenic risk based on the previous research data.
Nonetheless, there are documented cases where skin cancer developed on the back of the hands in individuals who regularly underwent manicures using UV lamps. For instance, two patients diagnosed with squamous cell carcinoma did not have any significant risk factors such as genetic predisposition or regular outdoor work. However, the authors of the article reporting these cases emphasize that it is not possible to draw convincing conclusions from them, as “after” does not necessarily mean “due to.” In another case, a patient who had been receiving biweekly manicures for 18 years was diagnosed with skin cancer. Like the previous cases, she had no history of cancer in her family. However, in addition to receiving manicures, she also frequented tanning salons, making it difficult to establish a causal relationship.
In 2014, dermatologists in the United States tested the radiation emitted by lamps in 16 different salons. They compared the energy density of ultraviolet radiation that can damage DNA (600 kJ/m2) and found that it takes between 8 to 208 sessions, depending on the type of lamp, to cause damage to keratinocyte cells. While this might seem concerning, it’s important to note that natural cellular metabolites are believed to cause tens of thousands of DNA damage events per day per cell during normal cellular activity.
Fortunately, our bodies have the ability to repair their own DNA, and the risk of cancer only arises when the ability of DNA to repair itself is reduced due to inherited mutations or severe and frequent damage that accumulates over time. Therefore, the fact that DNA damage occurred after the eighth manicure session does not necessarily mean that the risk of developing cancer is high.
The researchers noted that although the risk of multiple manicures with lamp use remains unknown as people were not included in the study, the data collected suggests that even with repeated use of this procedure, the risk of developing cancer is low.
Experts emphasize that many salons have switched from ultraviolet lamps to LED lamps, but both types of lamps emit ultraviolet radiation. Surprisingly, LED lamps actually emit more ultraviolet radiation than ultraviolet lamps. However, LED lamps are still considered safer because they allow nail polish to dry faster, which reduces the exposure time.
Insufficient evidence exists to indicate that the regular use of ultraviolet lamps during manicures significantly increases the risk of developing skin cancer. Experts acknowledge that additional research is necessary to conclusively determine the impact of these lamps. Furthermore, the frequency of receiving such manicures is a significant factor – if it is only a few times a year, there is no cause for concern according to experts, but if it is every week, taking precautionary measures may be necessary. People with heightened sensitivity to UV radiation, whether due to natural causes or medication use, should also consider taking preventive measures. To minimize the risk of any adverse effects from ultraviolet lamps on the skin, experts recommend either applying waterproof sunscreen with an SPF of 30 or higher to your hands (or feet, in the case of a pedicure) or wearing gloves with exposed fingertips.
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