Doctors fighting the cholera outbreaks in the 1800s discovered that people who worked with copper in either refineries or as tradesmen were much more resistant to the cholera epidemic. It turned out that copper is antimicrobial. It kills bacteria and viruses, sometimes within minutes. People who worked with it were safer from disease.
Further testing has shown that copper kills many viruses, from E.coli to MRSA to SARS to possibly the novel coronavirus. Michael Schmidt, a professor of microbiology and immunology at the Medical University of South Carolina suggests that if it were used in hospitals and high-traffic areas then it would be a great weapon in fight viral illnesses.
On copper surfaces, bacteria and viruses die. When a microbe lands on a copper surface, the copper releases ions, which are electrically charged particles. Those copper ions blast through the outer membranes and destroy the whole cell, including the DNA or RNA inside. Because their DNA and RNA are destroyed, it also means a bacteria or virus can’t mutate and become resistant to the copper, or pass on genes (like for antibiotic resistance) to other microbes.
So why don't we use it? Plastic is cheaper.
“What happened is our own arrogance and our love of plastic and other materials took over,” Schmidt said of the cheaper products more frequently used. “We moved away from copper beds, copper railings, and copper door knobs to stainless steel, plastic, and aluminum.”
Schmidt said that using copper along with standard hygiene protocols hasbeen shown to reduce bacteria in health care settings by 90 percent. They would be much better used as doorknobs, rather than the stainless steel ones that are in popular use and have a very high viral retention rate. This is especially important with the Coronavirus, which can remain infectious for up to five days on most surfaces.
The material cost of copper was also considered an impediment, but studies from 2015 have shown that the upfront cost is quickly mitigated by the long term health benefits of the metal. Another argument is that copper takes more effort to polish and clean, but even unpolished it won't lose its antiviral capabilities.
"Your payback is literally in less than two [prevented] infections,” Bill Keevil, a professor of environmental healthcare at the University of Southampton, said. “I really struggle with this. Since 2013, I have been literally begging, groveling, pleading, with any and all concerned to make a completely copper encapsulated [hospital] bed."