Feb 256 min read

Tattoo Toxicity

While tattoos are a common form of often meaningful self-expression, these permanent additions to the body can have many detrimental health effects. During the tattooing process, tattoo ink reaches the blood and lymph fluids, which spread the ink throughout the body. Ink also travels from the tattoo site to other parts of the body after the tattoo has been applied. One study estimated an 87-99% decrease in tattoo pigment concentration in the skin over time after tattooing, suggesting that much of the tattoo is transported to other parts of the body or broken down in the skin. Additionally, the process of tattooing can increase inflammation and cause an immune response, and, alongside the ink, tattoo needles can release tiny particles of metals into the skin and lymph nodes. With 32% of American adults having a tattoo, and even higher numbers among younger people, more awareness and research on the toxins in tattoos is very important.

One of the main components of tattoo ink is the pigments. The pigments in tattoo ink are often actually the same as those used in products like paint and textiles, not specifically made for tattoos. Colorants in tattoos can be grouped into organic and inorganic pigments. Organic pigments include azo pigments and polycyclic aromatic hydrocarbons (PAHs), while inorganic pigments include titanium dioxide, iron oxide, and carbon black. A large number of tattoo inks use azo pigments. Azo compounds can break down into carcinogenic aromatic amines. Some inks, especially red and yellow ones, which usually contain azo pigments, can cause genetic changes. Different PAHs can be carcinogenic, irritating, and harmful to genes, fetuses, the liver, kidneys, and the immune, reproductive, and respiratory systems. Black ink is often composed of carbon black, which contains PAHs, with titanium dioxide or iron oxide additives. Exposure to sunlight can cause one form of titanium dioxide to form reactive, cell-damaging oxygen species, and iron oxide has been linked to inflammation, cell death, changes in mitochondrial function, cell harm from the production of reactive oxygen species, and genetic alterations. Pigments in tattoos can also lead to cellular changes like the alteration of lipids and proteins. Among tattoo inks, red is the most dangerous (likely due to the increased levels of azo pigments) and black is the least dangerous. Many tattoo inks do not accurately report their ingredients.

Some metals, including cobalt, cadmium, mercury, manganese, and aluminum, are also used as colorants. Cobalt exposure can lead to nervous system issues, harm to cell signaling, skin and eye irritation, cell damage from the formation of reactive oxygen species, and possibly cancer. Cadmium is a carcinogen and can harm the kidneys, liver, and reproductive and respiratory systems. Mercury is a reproductive toxin. Manganese is a neurotoxin and skin irritant with potentially harmful effects on the liver, digestive system, and kidneys. Aluminum has been linked to genetic harm, inflammation, protein misfunction, metabolic issues, neurological issues like Alzheimer’s, dementia, and autism, cell death, infertility, diabetes, breast cancer, and respiratory, immune, digestive, and cardiac problems.

Tattoo ink can be contaminated with primary aromatic amines (PAAs), polycyclic aromatic hydrocarbons, phthalates, and nitrosamines, all of which can harm DNA, and metals such as nickel, chromium, arsenic, and lead. Black and grey tattoos usually contain higher levels of PAHs, while other colors contain more aromatic amines. For example, carbon black ink contains PAHs like benzo(a)pyrene. PAAs and nitrosamines are carcinogenic. Phthalates have been linked to many different health effects, including reproductive, developmental, liver, kidney, and lung issues. Nickel can cause allergic reactions, immune and nervous system harm, cancer, cardiovascular issues, respiratory issues, mitochondrial harm, genetic alterations, and cell death. Chromium and lead are very common in tattoo inks. One study found levels of both of these metals in almost every tattoo ink tested. Chromium is an irritant and carcinogen, and lead is a neurotoxin, carcinogen, and reproductive toxin that has also been linked to kidney and fetal harm. Arsenic has been linked to cancer, diabetes, hearing loss, and bladder, lung, kidney, heart, digestive, blood, liver, brain, and skin issues.

Tattoo inks can also include additives, such as preservatives, thickening agents, PAHs, nanoparticles, and surfactants. Some tattoo inks can contain fragrance, a mixture of chemicals linked to a variety of issues, including reproductive harm, endocrine disruption, and cancer, among many others. Many different preservatives are used in tattoo ink, including formaldehyde, phenol, parabens, and phenoxyethanol. Formaldehyde is a carcinogen and skin irritant. Phenol has been linked to skin, heart, immune, and potentially nervous system and developmental issues. Exposure to parabens has been linked to many issues, including endocrine disruption, reproductive harm, altered organ weights, allergic reactions, and breast cancer. You can read more about parabens here. Phenoxyethanol can potentially irritate the skin. Some examples of thickeners used include silicones, acrylates, and polystyrene. Some silicones can cause inflammation, cell death, endocrine disruption, fertility issues, and cancer, and some acrylates have been linked to cancer, fetal developmental harm, endocrine disruption, fertility issues, cell damage and death, irritation, DNA damage, and lung, liver, kidney, nervous system, and digestive harm. The small size of nanoparticles makes them more susceptible to being transported to the lymph nodes, which could lead to increased exposure to the rest of the body. Large particles in tattoos have still been shown to be moved into the lymph nodes as well, however.

Sun exposure can break down tattoo ink, forming a variety of toxic compounds like hydrogen cyanide, which can inhibit the normal function of mitochondria and thus cell energy production, and aromatic amines. Laser tattoo removal works similarly, but it very quickly breaks down the ink particles. Some of the most common products from the breakdown of tattoo ink by light are benzonitrile, aniline, and 3,3'-dichlorobenzidine. Benzonitrile can irritate the skin and lead to genetic abnormalities, aniline can irritate the skin, eyes, and respiratory system and potentially cause cancer, and 3,3'-dichlorobenzidine is carcinogenic and can harm fertility. Besides those effects, other compounds produced can cause organ damage. Light exposure can also cause ink to produce reactive oxygen species, which can lead to skin inflammation and damage DNA. Additionally, some body processes can produce toxic chemicals, including PAAs and PAHs, from the compounds in tattoos.

There is still much to be learned about toxins in tattoos, but what is known is concerning. Tattoos often contain toxic metals, purposely or not, and carcinogenic PAHs and PAAs, either directly from the ink or produced from the body or sun exposure. It is important to consider the lifelong source of toxins that tattoos provide before getting one.