Before anyone signs up for a tattoo, Once common only to sailors, criminals, and other tough customers, tattoos now adorn nearly one in three Americans, per a 2015 Harris Poll. There's still reason to associate them with danger thanks to toxic substances in tattoo inks. Before anyone signs up for a tattoo, they should ask themselves these questions first . And then consider the fact that many colors of tattoo ink contain heavy metals , according to a report in Scientific American , including lead, mercury, arsenic, beryllium, and chromium. Red dyes have been found to contain cadmium and iron oxide. While these metals give dyes their permanence, they are also linked to cancer, birth defects, allergic reactions, and other scary side effects. Tattooed patients undergoing MRIs have suffered first-degree burns as the metals in their tattoo ink heated up.The U.S. Food and Drug Administration does not regulate tattoo ink, and no pigments have been approved for injection...