GRENOBLE, FRANCE — A new study published in the journal Particle and Fiber Toxicology has found that tattoo needles deposit metal particles such as nickel and chromium into the skin during the tattooing process.

These particles are then transported from the tattoo site to the body's lymph nodes, where their sizes ranged from 50 nanometers to 2 micrometers, according to a news release by the European Synchrotron Radiation Facility.

Researchers analyzed a tattoo needle by using a scanning electron microscopy to take a closer look at the needle before and after the tattoo process.

They found that the needle showed abrasions from certain tattoo inks that contain titanium dioxide, a white pigment that is usually mixed in bright colors such as green or blue. Researchers did not find the same result with carbon black ink.

The news release noted that further studies would be needed to understand the metal particles' impact on tattoo allergy formation and long-term impact on human health.