Besides getting stuck with a Hello Kitty tattoo for life, there's another downside to getting skin ink: Microscopic particles can taint your lymph nodes. A new study found that after a person gets a tat, nano traces of the ink containing preservatives and contaminants work their way into the person's nodes, whose job is to cleanse the body of toxins, AFP reports. Researchers write in Scientific Reports that colored tattoo ink, a mix of organic and inorganic pigments, can contain nickel, chromium, manganese, and cobalt. After black, made from iron oxides and carbon, the most common ink in tattoos is titanium dioxide, a white pigment found in sunscreen that can cause irritation when used in skin art. Co-author Hiram Castillo-Michel of the European Synchrotron Radiation Facility in France says when getting a tattoo, clean needles aren't the only concern.
"No one checks the chemical composition of the colors, but our study shows that maybe they should," he says. Stained lymph nodes are not news in the tattoo world, Discovery reports, noting that as the body tries to reject insoluble ink injected below the skin's epidermis, tattoos leak ink, plasma, and lymphatic fluid. Using X-ray fluorescence to study the nodes of tattooed cadavers (an admittedly small sample of four corpses, with two non-tattooed control cadavers), the scientists found the smallest bits of blue and green pigments were the mostly likely to linger, causing chronic enlargement of exposed nodes. While they found "strong evidence" of long-term toxin deposits, the next step is to figure out the long-term health effects. (A political rallying cry spawned a spate of tattoos.)