Can Acrylic Nails Cause Cancer?
Acrylic nails are a popular beauty trend, where a nail tip is applied to a cut nail, and coated with acrylic which is then hardened under UV light. This creates a hard, shiny surface on top of the nail, which can be decorated according to personal preference.
There are concerns about the potential health hazards associated with acrylic nails, including the potential risk of cancer. The primary risk, however, is accumulation of bacteria under the attached acrylic nail, leading to several healthcare institutions banning acrylic nails for their employees.
Acrylic nails and cancer: Scientific evidence
There is currently no available scientific study directly linking acrylic nails to cancer in a causal relationship. However, there are some well-known cancer risks that arise during the process of fitting an acrylic nail.
UV light exposure
Ultraviolet radiation (UV) is a known mutagen, meaning it causes damage to the DNA. This can, in turn, result in development of cancer via multiple processes, including direct DNA damage, production of reactive oxygen species (molecules that disrupt other molecules when they are present in excessive amounts by binding to them), and modulation of the immune system [1, 2].
Unprotected exposure to UV radiation is a known cause of multiple skin cancers, including basal cell carcinomas and melanomas.
The UV lamps used to cure the acrylic nail are an artificial source of UVA radiation. This is a type of radiation that affects the outer layers of the skin, resulting in a melanin (pigment) response from the body as a protective measure - this is the mechanism of tanning. UVA radiation has been implicated in skin ageing, development of wrinkles (as it damages the collagens and elastins - molecules that maintain the skin structure), and indeed cancer. With that, there is a concern for the curing process of artificial nails and development of skin cancer.
There have been multiple reports of individuals with a history of acrylic nails usage developing skin cancer on their hands [3, 4]. However, it is worth noting that the prevalence of this is very low - another study involving tens or hundreds of thousands of women using a UVA nail lamp regularly detected only one case of skin cancer [5].
It is also worth noting that the dose of UV radiation during the acrylic nail application process is low - a study measured the dose and concluded it is comparable to what a person will get when standing in the sun at noon in the summer in Spain for 3.5-6 minutes [6, 7].
It is important to note that everyone should exercise appropriate UV protection, including wearing sunscreen or UV-blocking clothing when outside. Additionally, it is advised to visit a dermatologist for a routine checkup annually to assess all skin lesions and blemishes, as early diagnosis is the single most important predictor of outcome in every cancer.
In the case of UV lamps, scientific literature recommends application of sunscreen (SPF >30) to the hands before exposure to the UV lamp, or UV-blocking gloves are also an option [8, 9].
Formaldehyde
Formaldehyde is sometimes an ingredient in the acrylic nail as a preservative and hardening agent. Formaldehyde is a known carcinogen according to the International Agency for Research on Cancer [10].
Formaldehyde is a known causative agent of multiple diseases, including asthma and cancers [10]. This is likely a result of a mechanism where formaldehyde increases oxidative stress and damages DNA [11]. Oxidative stress is a process where the body fails to neutralise reactive oxygen species by antioxidants - this has been associated with damage to multiple important molecules and is a driver of cancer invasiveness and metastasis.
Studies have established a correlation between exposure to formaldehyde and cancer development, particularly nasopharyngeal cancers (due to inhalation of formaldehyde) and leukaemia [10]. Other studies reported an increase in mortality from cancers of the esophagus, stomach, rectum, liver, and lung among workers exposed to formaldehyde. However, these did not establish a clear exposure-response relationship [12]. A meta-analysis of these studies (and more) established an elevated relative risk for leukaemias (blood cancers) in people exposed to formaldehyde [13].
Consequently, the World Health Organisation recommends that levels of formaldehyde do not exceed the threshold value of 0.1 mg/m^3 (0.08 ppm) for a period of 30 min [10].
However, it is important to note that the concentration of formaldehyde in the nail products is very low, and there are formaldehyde-free options available.
Acrylates
Acrylates are the primary ingredient in the acrylic nail. There was a concern about some of these, including methyl methacrylate and ethyl methacrylate, and their role in cancer. There was a study reviewing their role in cancer, however, this concluded no genotoxic, mutagenic or carcinogenic properties. The only instance when these acrylates caused tumours to grow was in very high doses with long-term tissue damage in animal models, which is very unrealistic in the case of acrylic nails [14].
Benzene exposure
Benzene is a widely-used chemical in manufacturing of plastics and pesticides [15]. Some sources indicate that some acrylic nail materials may contain benzene.
Benzene is a known carcinogen, with a role in lung cancers [16], as well as colorectal cancers [17]. This is likely due to a mechanism where benzene interacts with tumour suppressor genes - a set of genes with roles in killing a cell if it turns cancerous [18]. However, more research is needed to fully understand the extent of these associations and the mechanisms involved, and it is important to note that
- the manufacturers aim to minimise the content of benzene in the acrylic nails, and
- not all nail products contain benzene.
Summary
Acrylic nails are a potential concern in development of cancer. This is due to presence of several potentially carcinogenic chemicals in the formula, including formaldehyde, acrylates and benzene, as well as the UV radiation that is used to cure and harden the nail. However, there is no scientific evidence linking acrylic nails to cancer in humans, as the incidence of cancer in users of acrylic nails is no higher than in general population.
