As tattoos have become more fashionable they have attracted more scientific research, and concern is now emerging about a possible long-term health risk.
There is solid science to show that many of the inks used in tattoos contain carcinogens. This means people are having cancer-producing particles injected directly into their skin.

But oddly enough, they are not developing skin cancers. One explanation is that these particles are stable. If they were not stable, the tattoo would not be permanent.