The ability to recycle metals provides an enormous environmental benefit. In fact, a 2011 study on the impact of funeral practices (Keijzer 1, 2) found that alkaline hydrolysis is more environmentally friendly than even natural burial. This is true even when natural burial was considered at its optimal scenario, known as green burial. Green burial was defined as no body bag, no embalming, the most ecologically friendly biodegradable body covering (which happened to be cardboard), no use of an elevator, graves dug by hand, no monument – only natural markers, only biologically degradable clothing, no jewels, no maintenance of burial grounds, and more people buried per graveyard. Even though green burial directly uses the least amount of energy, the reclamation of metals from bodies that undergo alkaline hydrolysis more than offsets this energy gap.
We can look to the types of metals used for implants and how they are made to understand the environmental credit of the recycling. Most medical implants are made of titanium. While titanium is the ninth most abundant element on Earth, its acquisition comes with a steep environmental cost. The cost to obtain and transport the materials used to make titanium – often from other countries – is one aspect, while the actual process to turn it into usable products is another (extraction, purification, reactor, alloy creation, and byproduct management). According to the United States Geological Survey, the US has become highly dependent on the import of materials used to make titanium.
A 2017 Italian study (De Angelis, et al.) found that people average one half pound of metal per individual. Metal implants are even more common in the United States and Canada. It was estimated in 2014 by a study conducted at Mayo Clinic that greater than 7 million Americans have artificial hips and knees, with more than 600,000 knees and 400,000 hips replaced each year. A knee replacement weighs 1-2 pounds, and a hip implant weighs 3-5 pounds. According to the CDC’s most recent death statistics, there are greater than 2,744,248 deaths per year in the US alone. This equates to at least 1,262,354 pounds of precious metals that could be recycled each year, or enough precious metals to construct 4 Statue of Liberty sized-structures out of titanium each year. Aquamation allows a new life for these metals and prevents the environmental impact of creating new.