Worth remembering a few things: - This isn't 90% "of tattoo ink", it's 90% of the inks they tested. Most tattoo ink is black, which their tests indicate is acc

Worth remembering a few things: - This isn't 90% "of tattoo ink", it's 90% of the inks they tested. Most tattoo ink is black, which their tests indicate is accurately labeled (edit: black ink is mostly just the element carbon so this isn't surprising). - This kind of problem is why experienced tattooists will test colors on peoples' skin to look for reactions. - Tattooing, though under-studied, depends on the ink largely sitting under the skin but generally being stable. While it's totally possible that decay over time could expose your organs to the contents of the ink, when it works well the ink is just sitting there so risks should be low. - Obviously this should be corrected and is a real indictment of the medical community's position that they won't study tattooing as a procedure we could improve (the general position on tattooing is "don't do it").