People are increasingly made of plastic. The material from our discarded water bottles gets ground up into microparticles, which end up everywhere in the environment. Our oceans alone have an estimated 150 million tons of plastic in them. We then nosh on 50,000 of these pieces of plastic a year, which have been discovered taking up residence in our livers, kidneys, and lungs. It’s sickening to consider, and we still don’t understand the long-term health ramifications.
But what if our body could actually recycle plastic, breaking it down to keep this waste out of our landfills and oceans?
The catch? This approach only works with a certain type of bioplastic, which is generally considered safe for the human body. Petroleum-based plastics, such as the bags that fill our oceans, need not apply.
That said, it’s obvious that Harkness finds his own idea of turning the 7 billion humans on earth into recycling facilities to be at least a little alluring, because the science is feasible, even if the logistics are not. His project focuses specifically on polylactic acid (PLA) bioplastic. Developed from materials such as corn starch, PLA is a common 3D-printing material that’s generally considered to be safe for human bodies. Harkness points out that it’s used in all sorts of medical applications, such as medical implants, and it naturally breaks down in your body. (Just because your body can break down PLA plastic, and it’s beneficial in some medical contexts, doesn’t mean it has no effect on health. Research from 2019 found PLA to be toxic to the organic tissue of mice.)
Harkness has given just one tattoo with the Biorecycling Machine to date, but it was with typical, rather than PLA-based ink. That’s because Harkness is uncertain if the plastics he’s sourced have undisclosed chemical contaminants. But if the project ever scaled, Harkness suggests an alternative to human subjects: the countless pigs, cattle, and goats that are already tattooed by farmers each year.