It's Not Just the Ink: How Tattoo Needles Deposit Nickel and Chromium in Your Skin

pmc.ncbi.nlm.nih.gov/articles/PMC6710876/

This was the first study to investigate and confirm that metal particles from tattoo needles themselves (not just the ink) get deposited in human skin and then translocate to lymph nodes. Here's what they found:

Although tattoo needles contain high amounts of sensitizing elements like nickel (6-8%) and chromium (15-20%), their influence on metal deposition in skin had never been investigated. The researchers reported the deposition of nano- and micrometer sized tattoo needle wear particles in human skin that translocate to lymph nodes.

They used synchrotron-based nano-X-ray fluorescence to analyze human skin and corresponding draining lymph nodes from five tattooed donors, plus a biopsy from a patient with a confirmed nickel allergy triggered by their tattoo. They then validated their findings by tattooing pig skin under controlled conditions.

A key finding was that needle wear significantly increased upon tattooing with titanium dioxide (TiO2) white ink compared to carbon black pigment. The TiO2 particles are abrasive and essentially sand down the needle surface during tattooing. SEM images showed completely polished needle surfaces after tattooing an area as small as 2-3 square centimeters with TiO2 ink. That's a striking finding — a tiny amount of white ink work was enough to visibly erode the needle.

The lead researcher explained: "There is more to tattoos than meet the eye. It is not only about the cleanliness of the parlour, the sterilization of the equipment or even about the pigments. Now we find that the needle wear also has an impact in your body." EurekAlert!

The research team believes the metals from the needle were deposited in the body and then transported into the lymph nodes with lymphatic fluid, or alternatively by phagocytes (the body's immune defense cells). The T lymphocytes in the lymph nodes can then trigger a type IV allergy.