When thinking about getting inked, it's wise to spend some time researching the best – and safest – tattoo parlours. After all, everything from hepatitis B to HIV can be transmitted via a contaminated needle.
But there's another aspect of getting a tattoo that you should probably be thinking about before you book that appointment: the chemical composition of ink itself and the effects this could have on your body, as a new study suggests.
The research, published in the peer-reviewed journal Scientific Reports, found that microscopic particles from coloured tattoo ink can find their way into the body and end up in the lymph nodes long-term. Lymph nodes are crucial parts of our immune system.
They're the small, bean-shaped glands that help to carry fluid, nutrients and waste material around the body as part of the lymph system, which protects us from disease. When they're blocked, they swell up and are less able to fight infections.
The scientists used X-rays to identify the particles in the skin and lymph nodes and found that particles of ink – which may be as tiny as a few millionths to a few billionths of a centimetre – can include preservatives and contaminants such as nickel, chromium, manganese and cobalt.
After carbon black, titanium dioxide is the second-most common ingredient used in tattoo inks. The white pigment, also found in food additives, sunscreens and paints, is used to create certain colours and has been linked to delayed healing, itching and skin irritation. Past research by the International Agency for Research on Cancer also found that inhaling the chemical can be a health risk.
"When someone wants to get a tattoo, they are often very careful in choosing a parlour where they use sterile needles that haven’t been used previously," said Hiram Castillo, one of the study's authors, from the European Synchrotron Radiation Facility in France. "No one checks the chemical composition of the colours, but our study shows that maybe they should."
The next step in the scientists' research is working out the adverse effects of these tiny particles on the body, including inflammation, they said. While it's not clear exactly how the ink may affect us, it's surely something to think about before you book in for your next tat.