Really excited to announce that our group's R15 proposal on the Photochemistry of Tattoos was funded by NIH! We understand very little about how light breaks down tattoo inks and what risks that poses. To celebrate, here are some other things you might not know about tattoos:

(2/) Something like 40% of Americans between the ages of 18 & 34 have at least one tattoo. In Europe, the numbers are even higher - half of Swedes and Italians are estimated to have 1+ tattoos.

(3/) Though the FDA has the authority to regulate tattoo inks, it very rarely exercises that authority. Inks in the US do not need to disclose the components, though inks in Europe do. Studies in Europe have shown that upwards of 1/3 of the time, the label is inaccurate.

(4/) Nanoparticles and carcinogens are common in tattoo inks. In 2009, a European study of 56 commercial inks found 36% had a toxic metal concentration greater than 1ppm. 62% of the inks exceeded safe limits for chromium. Other studies have found similar results.

(5/) Delayed allergic reactions to tattoos are common and worsen with exposure to sunlight, though we don't know why. Red inks most commonly induce allergic reactions.

(6/) On a global scale, the tattoo removal industry is estimated to be about $11 billion per year. Training to remove tattoos takes about 2 days and only 17 states require an M.D. on site (though onsite is loosely defined).

(7/) Most tattoo removal lasers are Q-switched, class IV medical lasers and in a university setting would require extensive training and safety controls.

(8/) The mechanism of laser tattoo removal has never actually been investigated. The main source cited for the process does not deal with tattoos at all. Instead, it deals with laser induced fragmentation of graphite nanoparticles. Graphite is not common in tattoo inks

(9/) Photodegraded tattoo inks often end up permanently accumulating in the lymph nodes and liver, though we don't understand how. This is a particular problem in the removal of lymph nodes to treat breast cancer.

(10/) Hopefully over the next 3 years we can start to address some of these questions. An exciting part of the grant involves an undergraduate-led effort to create an open source database characterizing commercial tattoo inks making the results available to artists and consumers