Once they were only on sailors and ladies in sideshows. Now tattoos are on everyone and their mother. At one time the risks of tattoos included the possibility of an infection at the tattoo site or a blood-borne infection like hepatitis C. But an article in the journal The Lancet reviewed the long-term effects of tattoo inks and found a lot of unknowns.
Although tattooing as a form of self-expression is at least 5,000 years old, it is now widespread. The risk of an infection from a tattoo is small but real. Up to 5% of tattooed people develop a bacterial infection. Allergic reactions to the inks can also occur, the report noted.
But it is the long-term effects of the ink that is cause for concern. Little is known about long-term effects like organ toxicity or cancer, according to the study. With the rise in the popularity of tattoos, there are many new colors and very large tattoos have become more common. In most countries, tattoo inks are classified as cosmetics, but cosmetics sit on top of the skin and are not injected into the skin.
There are no industry standards for the ingredients in tattoo inks. Modern tattoo inks mostly are made up of organic pigments (as in organic chemistry, not organic gardening). They may also contain preservatives and contaminants like nickel, arsenic and lead.
There is also very little study of what happens to ink when it is inserted into the skin. Some ink is carried away from the skin and into the rest of the body. This is why older tattoos do not look at bright as new ones. Examinations of decades-old tattoos on deceased people have found that up to 90% of the ink is gone from the skin. It is not known where that ink goes or how it is carried away.
Tattoo parlors are regulated by the states. Some states require tattoo artists to have many hours of study in an apprenticeship with a trained tattoo artist. Others just require training in infection control and sterile technique.