Tattoos Tint Your Insides, Too

by Maria Gaura

Tattoos don’t just illustrate your skin. They can also decorate your internal organs, dyeing lymph nodes green, red, blue, and orange with particles of free-floating tattoo ink.

In a study published September 12 in the online journal Scientific Reports, researchers from the German Federal Institute for Risk Assessment (BfR) sampled lymph nodes from donated cadavers and found them brightly stained with the same inks displayed in the donors’ tattoos. The pigments were matched using mass spectrometry analysis.

The study results “provide strong evidence” that multicolored tattoo inks do not stay put when they are injected into the skin. Instead, some portion of the inks are circulated throughout the body, ending up as long-term deposits in lymph nodes – and possibly other organs.
The study, which focused on the migration and precise chemical analysis of colored and white tattoo inks, builds on previous work linking blackened lymph nodes with black tattoos. (Here is an image of an ink-blackened lymph node, viewer discretion advised.)

Tattoo-ink blotches in lymph nodes can complicate diagnosis of cancer and other ailments. To date, there is no evidence that ink-stained nodes pose a disease risk. However, the study notes that “the deposit of (pigment) particles leads to chronic enlargement of the respective lymph node, and lifelong exposure.”

Also, research on the long-term health effects of tattooing is in early stages, and scientists note that tattoo inks and pigments are full of sketchy, unregulated, and downright toxic ingredients. Interestingly, animal experimentation to address these issues is considered unethical in the European Union, because “tattoos are applied as a matter of choice, and lack medical necessity, similar to cosmetics,” the researchers note.

Black tattoo inks generally consist of soot products like Carbon Black or polycyclic aromatic hydrocarbons (PAH), both known carcinogens. The colored pigments found in lymph nodes by BfR researchers consisted of nano-sized particles of copper, nickel, chromium, manganese, cobalt, aluminum, iron, and various dyes.  

In future, the BfR researchers plan to investigate the pigment and heavy-metal burdens of other human organs and tissues to track possible biodistribution of tattoo ink elsewhere in the body. 
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