Some studies have found a link between tattoos and an increased risk of cancer, and recent evidence appears to suggest that tattoos could heighten the risk of blood cancer, in particular.
What biological mechanisms might explain this link, and should people really worry about the health implications of getting a tattoo?
Do tattoos really cause blood cancer?
According to the Longman dictionary, a tattoo is a picture or writing that is permanently marked on the skin using a needle and ink. Tattoos can be strikingly beautiful forms of art, and they are increasingly popular.
A Pew Research Centre survey conducted in 2023 revealed that 32% of Americans have at least one tattoo, and 22% have several.
Beyond adorning the body on a permanent basis, tattoos can also provide a meaningful way of commemorating important life events, or they can be symbols of mental and emotional healing.
However, some questions remain around the potential health implications of getting a tattoo, and recently, researchers have been homing in on the ways in which tattooing could affect a person’s physical health in the long run.
One study, published in Applied and Environmental Microbiology at the start of July 2024, tested samples of 75 tattoo and permanent makeup inks commonly used in the United States, and found that 26 of these were contaminated with infection-causing bacteria.
These included Staphylococcus epidermidis, an infection that can cause severe health complications, and Cutibacterium acnes, which causes acne.
More worryingly, a study from Lund University, in Sweden, which appeared in the journal eClinical Medicine the previous month, found that any-size tattoo was linked to a 21% higher link of lymphoma, a type of blood cancer.
To identify this link, the Lund researchers looked at data from the Swedish National Cancer Register, focusing on people who were 20–60 years old, when they received a lymphoma diagnosis, between 2007 and 2017.
But what does this link mean? How come tattoos may increase the risk of blood cancer?
Are some types of tattoos riskier than others, and if so why?
Finally, how worried should people be about getting cancer if they have tattoos, and what should they keep in mind when considering whether or not to get a tattoo?
Cancercenter.com noted that with the popularity of tattoos rising, questions surrounding their safety have increased, as well.
It stated, “While tattoos are generally thought to be safe, research into the inks and ingredients used isn’t comprehensive, meaning they haven’t all been studied yet for their safety or role in cancer. Chemicals found in some tattoo ink may be toxic or carcinogenic (cancer-causing), for example. And having a tattoo may also make it harder to detect cancer on the skin.”
The site also stated that tattoos may also cause skin infections, allergic reactions and scarring, especially if you don’t see a licensed tattoo artist or if the tattoo hasn’t healed properly.
“Today, most places that offer tattoos are much more regulated than they used to be, so the risk of contracting conditions like hepatitis or infections is pretty darn small, thankfully,” says Anthony Perre, MD, FACP, New Patient Intake Physician at City of Hope, Atlanta, United States of America.
WHO statement on tattoos, cancer and immune system
The World Health Organisation, on its website wrote on the link between tattoos, cancer and other infections:
Tattoos and lymphoma: possible effects on the immune system?
The chronic exposure of the lymphatic tissue and potentially other organs to tattoo inks is very likely. Therefore, tattoo-induced carcinogenesis cannot be ruled out. Because cancer develops in the most exposed organs, lymphomas (Hodgkin lymphoma and non-Hodgkin lymphomas) are of particular concern, even more so than skin cancer, of which most types develop in the epidermal layer of the skin, which has a comparatively low exposure.
Lymphomas comprise many heterogeneous neoplasms that develop in the lymphocytes (white blood cells) in the lymphatic system. For example, non-Hodgkin lymphomas may arise in B cells, T cells, or natural killer cells, which all play different important roles in the immune system’s defence against pathogens, toxins, and clonal expansion of cancer cells through complex inflammatory reactions.
The consequences of impaired immune function, such as in organ transplant recipients and HIV-positive individuals, in relation to cancer development are well established. Particularly for lymphomas, the link to compromised immunity is important. The main known risk factors for lymphomas are infectious diseases associated with immunodeficiency, such as infection with HIV and Epstein–Barr virus (EBV), which may cause different types of lymphomas mediated by immunosuppression, disruption of normal cellular functions, chronic immune stimulation, abnormal T-cell activity, and oxidative stress. Similar to these mechanisms of action, the formation of reactive oxygen species and chronic inflammatory responses have been demonstrated in animal and cellular studies for the two main tattoo pigments, black (carbon black) and white (titanium dioxide).
This observation contributed to the IARC Monographs programme’s classification of carbon black particles as possibly carcinogenic to humans (Group 2B). Independent adverse effects of pigment load and pigment toxicity of zinc and cobalt pigments – metals frequently found in tattoo inks – on different immune and inflammatory markers have been seen in vitro even in a long-term scenario. The subsequent step, a potential carcinogenic effect of these pigment-induced processes, remains largely unexplored. However, development of lung cancer and skin cancer through immunomodulation after exposure to black pigment has been observed in animal studies. It is not known whether a high exposure to tattoo pigment particles in lymph nodes or the skin could trigger similar processes in humans.
What about effects on other organs? Because of the poor solubility of most tattoo pigments, the natural attempts of the immune system to eliminate and wash out the pigment particles may often be unsuccessful and could lead to a constant low-dose inflammatory reaction that overstimulates the immune system. However, very low doses of the pigment-associated substances might be cleared by the intracellular acids of macrophages and could subsequently be transported to other organs. In animal studies, tattoo pigments have been found in the kidney, the liver, and the spleen.
Therefore, although this has never been studied in humans, exposure to hazardous ingredients of tattoo inks and even subsequent cancer development should not be ruled out. A further potential hazard is posed by the fact that many tattoo pigments are nanoparticles. Because of their small size, nanoparticles penetrate epithelial layers more easily and can even overcome blood–tissue barriers, including the blood–brain barrier. These properties are useful for medical purposes, such as the delivery of drugs encased in nanoparticles, but they could also increase the toxicological potential of the particles. The long-term health effects of these nanoparticles are still largely unexplored, but because they also have a harmful effect on the immune system, their carcinogenic influence cannot be ruled out.
Tattoo-associated viral infections
In contrast to the unknown potential direct impact of tattoo ink on the risk of certain types of cancer (described above), the increased risk of viral infections through poor hygiene conditions during tattooing is established. As known from needle sharing in intravenous drug users, the piercing, puncturing, and injecting using needles is associated with risks of persistent viral infections, which in turn have associated risks of cancer. Tattooing incurs a risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, and tattoo-related HIV and monkeypox infections, although rare, have also been reported. HCV and HBV infections themselves are associated with a higher risk of developing non-Hodgkin lymphomas and liver cancer, and HIV infection is linked with increased risks of the HIV-associated and AIDS-defining malignancies (non-Hodgkin lymphomas, cervical cancer, and Kaposi sarcoma) and other infection-related cancer types (Hodgkin lymphoma, liver cancer, and anal cancer). Although in Europe, improved hygiene standards have drastically reduced tattoo-related infections during recent decades, the rising popularity of tattooing in low- and middle-income countries is worrying, in light of possible poor hygiene conditions, because it may give rise to many new cases of viral infections and associated cancers.
