How tattoo ink travels through the body, raising risks of skin cancer and lymphoma

Study concludes that the larger the tattoo, the greater the odds of developing cancer In a nutshell

* Danish twin study found people with large tattoos (bigger than palm-sized) had 2.73 times higher rate of developing lymphoma and 2.37 times higher rate of skin cancer

* Tattoo ink particles migrate through the body to lymph nodes and other organs, potentially causing chronic inflammation that may increase cancer risk

* Time between getting a tattoo and cancer diagnosis averaged 8 years for lymphoma and 14 years for skin cancer, suggesting a substantial latency period

ODENSE, Denmark — Tattoos have become a mainstream form of self-expression, adorning the skin of millions worldwide. But a new study from Danish researchers uncovers concerning connections between tattoo ink exposure and increased risks of both skin cancer and lymphoma.

Approximately one in four adults in many Western countries now sport tattoos, with prevalence nearly twice as high among younger generations. The study, published in BMC Public Health, adds to growing evidence that the popular form of body art may carry long-term health consequences previously unrecognized.

The study’s lead author, Signe Bedsted Clemmensen, along with colleagues at the University of Southern Denmark, analyzed data from two complementary twin studies – a case-control study of 316 twins and a cohort study of 2,367 randomly selected twins born between 1960 and 1996. The team created a specialized “Danish Twin Tattoo Cohort” that allowed them to control for genetic and environmental factors when examining cancer outcomes among tattooed and non-tattooed individuals.

When comparing twins where one had cancer and one didn’t, researchers found that the tattooed twin was more likely to be the one with cancer. In the case-control study, tattooed individuals had a 62% higher rate of skin cancer compared to non-tattooed people. The cohort study showed even stronger associations, with tattooed individuals having nearly four times higher rate of skin cancer and 2.83 times higher rate of basal cell carcinoma.

Tattoo artist inking a client's arm Larger tattoos carry a greater risk of cancer than smaller ones, the study shows. (Photo by Tahir osman on Unsplash+) Size appears to matter significantly. Large tattoos (bigger than the palm of a hand) were associated with substantially higher lymphoma and skin cancer risks than smaller tattoos, potentially due to higher exposure levels or longer exposure time. This dose-response relationship strengthens the case for causality rather than mere correlation.

“This suggests that the bigger the tattoo and the longer it has been there, the more ink accumulates in the lymph nodes. The extent of the impact on the immune system should be further investigated so that we can better understand the mechanisms at play,” says Clemmensen, an assistant professor of biostatistics, in a statement.

Scientists have long known that tattoo ink doesn’t simply stay put in the skin. Particles from tattoo pigments migrate through the bloodstream and accumulate in lymph nodes and potentially other organs. The researchers proposed an “ink deposit conjecture” – suggesting that tattoo pigments trigger inflammation at deposit sites, potentially leading to chronic inflammation and increased risk of abnormal cell growth.

Black ink, the most commonly used tattoo color, has been a particular focus of concern. It typically contains soot products like carbon black, which the International Agency for Research on Cancer (IARC) has listed as possibly cancer-causing to humans. Through incomplete burning during carbon black production, harmful compounds form as byproducts, including benzo[a]pyrene, which IARC classifies as cancer-causing to humans.

“We can see that ink particles accumulate in the lymph nodes, and we suspect that the body perceives them as foreign substances,” explains study co-author Henrik Frederiksen, a consultant in hematology at Odense University Hospital and clinical professor at the university. “This may mean that the immune system is constantly trying to respond to the ink, and we do not yet know whether this persistent strain could weaken the function of the lymph nodes or have other health consequences.”

Colored inks pose their own problems. Red ink – often associated with allergic reactions – contains compounds that may release harmful substances when exposed to sunlight or during laser tattoo removal.

“We do not see a clear link between cancer occurrence and specific ink colors, but this does not mean that color is irrelevant,” notes Clemmensen. “We know from other studies that ink can contain potentially harmful substances, and for example, red ink more often causes allergic reactions. This is an area we would like to explore further.”

The researchers suggest that with tattoo prevalence rising dramatically, especially among younger people, public awareness campaigns might be needed to educate about potential risks.

“We are concerned that tattoo ink has severe public health consequences since tattooing is abundant among the younger generation,” they write in their conclusion. The team recommends further studies to pinpoint the exact biological mechanisms through which tattoo ink might induce cancer.

A Growing Body Of Research This isn’t the first research to raise alarms about tattoo safety. Previous studies have documented cases of skin conditions and tumors occurring within tattoo areas. However, this large-scale study provides some of the strongest evidence yet for a relationship between tattoos and cancer.

For those already sporting tattoos, the research doesn’t suggest panic – but awareness. The time between tattoo exposure and cancer diagnosis in the study was substantial – a median of 8 years for lymphoma and 14 years for skin cancer. This suggests that cancers develop gradually over time, and monitoring for any changes in tattooed areas might be prudent.

The rise in popularity of tattoo removal services presents its own concerns. The researchers specifically highlight that laser tattoo removal breaks down pigments into smaller fragments that may be more mobile within the body, potentially increasing migration to lymph nodes and other organs.

As with many health studies, this research doesn’t definitively prove causation, but it adds significant weight to growing evidence of long-term risks. The researchers point out that even with new European restrictions on harmful compounds in tattoo inks, the body’s immune response to foreign substances might be problematic regardless of specific ink components.

While tattoos have become a widely accepted form of self-expression, the study warns that individuals should consider the risks before heading back to the parlor for their next design. (© Nejron Photo – stock.adobe.com) Balancing Expression and Health

As tattoo culture continues to thrive globally, balancing personal expression through body art with health considerations becomes increasingly important.

With tattoos now firmly embedded in mainstream culture, this research doesn’t aim to stigmatize body art but rather to inform safer practices. Whether this means developing safer inks, improving tattoo application techniques, or simply making more informed choices about tattoo size and placement, understanding the biological impact of tattoo ink is essential for public health.

As the researchers conclude, further studies that pinpoint the biological mechanisms of tattoo ink-induced cancer are needed. Until then, those considering getting inked might want to weigh the aesthetic benefits against potential long-term health considerations – a balance that, like the perfect tattoo design, will be uniquely personal.

The Danish Twin Tattoo Cohort was established in 2021 specifically to investigate associations between tattoo exposure and cancer development. Researchers employed two complementary study designs: a case-control study of 316 twins born between 1960-1996, and a cohort study of 2,367 randomly selected twins. These twins were identified through linkage between the Danish Twin Registry and the National Cancer Registry using unique personal identification numbers. The study focused on twins where at least one had been diagnosed with lymphoma, skin cancer (excluding basal cell carcinoma), or bladder/urinary tract cancer after reaching age 20. Data collection occurred through a questionnaire survey from January to July 2021, which gathered information about tattoo status, age at first tattoo, colors used, tattoo size, and potential confounding factors like smoking, physical exercise, alcohol consumption, and education. Researchers then used time-based analysis to ensure accurate risk assessment, treating tattoo exposure as a variable that changed over time. This means individuals who got tattoos after cancer diagnosis only contributed risk time as unexposed subjects.

The study revealed significant associations between tattoo exposure and cancer risk across both study designs. In the case-control study, individual-level analysis showed that tattooed people had a 62% higher risk of developing skin cancer compared to non-tattooed individuals. When researchers examined 14 twin pairs where one twin had skin cancer and the other didn’t, they found a higher likelihood of the tattooed twin being the one with cancer. Particularly concerning was the finding that large tattoos (bigger than the palm of a hand) were associated with substantially higher risks: a 2.37 times higher risk for skin cancer and 2.73 times higher risk for lymphoma. The cohort study showed even stronger associations, with tattooed individuals having 3.91 times higher risk of skin cancer and 2.83 times higher risk of basal cell carcinoma. The median time between tattoo acquisition and cancer diagnosis was 8 years for lymphoma and 14 years for skin cancer, suggesting a substantial waiting period before cancer appears.

The researchers acknowledge several limitations to their study. First, the sample consists only of cancer survivors who participated in the survey, meaning those who died from severe cancer aren’t represented. Second, the study didn’t distinguish between decorative tattoos, permanent makeup, and medical tattoos, which may differ in size and ink composition. Third, the analysis of smoking as a contributing factor was limited, using only basic information about smoking initiation. The study also lacked information on sun exposure, a known risk factor for skin cancer with an unclear relationship to tattooing—tattooed individuals might either expose tattoos to show them off or protect them from sun damage. Another limitation is that association between tattoo ink and skin cancer could result from delayed detection due to tattoos concealing abnormalities rather than directly causing cancer.

The researchers propose that tattoo particles interact with surrounding tissue, causing inflammation that may eventually become chronic and increase cancer risk. This mechanism resembles the immune response seen in some other conditions involving foreign substances in the body. Importantly, this process doesn’t necessarily involve specific harmful agents in the ink—the body’s response to foreign substances itself may be problematic. However, when harmful compounds are present (as in black ink’s carbon black or colored inks’ azo compounds), the risk may be amplified. The relationship observed with larger tattoos strengthens the case for causality. The researchers express particular concern about laser tattoo removal, which breaks pigments into smaller fragments that may travel more easily through the body. The authors suggest that public health information campaigns could be effective preventive measures, as twin studies have shown that the decision to get tattooed is strongly influenced by environmental rather than genetic factors.

The research was published with open-access funding provided by the University of Southern Denmark. The authors declared no competing interests that might influence the study’s findings or interpretation. The study was conducted in accordance with the Helsinki Declaration, and while ethical approval was waived by the Regional Committees on Health Research and Ethics for Southern Denmark, the researchers obtained appropriate permissions for record linkages and informed consent from all participants. The project followed The Danish Code of Conduct for Research Integrity, ensuring scientific and ethical standards were maintained throughout.

This study, titled “Tattoo ink exposure is associated with lymphoma and skin cancers – a Danish study of twins,” was published in BMC Public Health (2025, volume 25, article 170) and is available under an open access Creative Commons Attribution 4.0 International License. The research team was led by Signe Bedsted Clemmensen from the Department of Epidemiology, Biostatistics, and Biodemography at the Institute of Public Health, University of Southern Denmark, with co-authors from the Danish Twin Registry, Department of Clinical Genetics at Odense University Hospital, Institute for Molecular Medicine Finland, Department of Haematology at Odense University Hospital, and Department of Clinical Research at the University of Southern Denmark.

When I was a commissioned Army officer from 1977 to 1997, I never saw an officer with a tattoo. It was limited to usually enlisted soldiers who had too much money on payday and soon parted with it. Now I see not only officers with large tatts but West Point cadets on the football team with the same thing. They are unbecoming of an officer, trashy especially on women and not something I would ever consider doing to myself.

My daughter has a sleeve tattoo. Her grandmother cried when she saw it. I asked her, couldn’t you have just put all those designs on a poster and hang it on the wall?

"A tattoo is a permanent reminder of one’s temporary insanity."

Than what is it when you have serial tattoos?>

Tattoo parlors provide an invaluable service to humanity. They mark the idiots so the rest of us will recognize them on sight. Saves valuable time in sorting the pepper from the fly specks.

It's baffling to me that when you're five years old and you draw on your arms with a pen (which eventually will wear off), they blame immaturity.

But when you're a grown-up and pay hundreds of $$$$$$$$$$$ to what is laughingly called "an artist" to draw on your arms in a way that won't come off, it somehow is "cool" of "hip."

Our kid’s tennis instructor was diagnosed with lymphoma a couple of years after he got a tattoo.

He said, I know it’s from the d@#n tattoo.

What can you say, or, do at that point?

Does it effect her work or job prospects?

I often wonder about this, with so many younger folks having mulitple tatts on their arms/neck, etc

Somehow, I got thru 4 years in the Marines without getting a tattoo.

I did 6 years in the Navy, never once had the urge to get a tattoo. One of my buddies did--he got a Snoopy carrying a golf bag on his arm. We gave him a lot of sh*t for that! That was mid-to-late 80s...I suspect tattoos are much more prevalent now. I just never understood the need to "express" yourself, or "preserve a memory" by the use of a tat.

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