Apparently one in four Australians has a tattoo. Not sure how reliable that number is but anecdotally you now see a lot more people with tattoos. Anything from fine line art work to dense tattoos covering large areas. There’s a long history of tattoos going back thousands of years with various meanings attached to them from status to occupation and military experience.
Why do tattoos stay put?
This is important to know because it could go to the issue of potential for harm. Tattoos involve ink and other substances – which I’ll come to later – being injected into the dermis (the layer under the skin). This causes damage and scarring with white blood cells called macrophages which specialise in chomping up foreign material coming into the area, taking up the ink and seem to become paralysed or die with the ink either still inside them or released into the tissues. Then the immune system seems to ‘wall-off’ the tattoo. Those two phenomena seem to be key to the permanence of tattoos. However, some ink particles do escape, usually into the lymph nodes which drain the inked area and many tattoos become fuzzy over the years because the immune system eats away at them.
What’s in tattoo ink?
These products are poorly regulated. There are dyes of various colours and chemistry; alcohols to prevent infection and other chemicals like glycerol to thicken the fluid. There are also contaminants and a study of tattoo inks in the United States found that often you can’t trust the ingredient list on the packet. The concerns are that an additive or adulterant such as polyethylene glycol (PEG) could damage the kidneys. Carcinogens such as polycyclic aromatic hydrocarbons are also found in tattoo inks and there are also worries about the risk of either cancer or the ink misleading pathologists looking at tissue samples.
Potential harms
Infection is always a risk such as from blood borne viruses or bacterial infection from the wound. Tattoo parlours usually take safety precautions but if you’re puncturing the skin multiple times, the risk never totally disappears. You can get an allergic reaction especially to red dyes, sometimes years after the tattoo was created. Kidney damage due to PEG is possible but rare.
A study of twins with and without tattoos in Denmark suggested a small increase in the risk of skin cancer and lymphomas, especially for large, densely inked tattoos. There’s also the potential for misdiagnosis. One case study of a man with a chest tattoo got the doctors worried about breast cancer when there was none and ink particles in lymph nodes can lead doctors to think that a melanoma has spread when it hasn’t.
The bottom line with tattoos is to be careful. Choose a tattoo artist who takes pride in cleanliness. Maybe avoid large, dense tattoos.
Further information
How safe are tattoos – really?: UCSF Synapse
What’s in my ink: an analysis of commercial tattoo ink on the US market: National Library of Medicine
