Copper has been found to have anti-microbial and anti-viral properties. It is why Roman soldiers would put a coin (made of copper) on their sword wounds....it reduced the chance for infection.
Our elimination of brass door knobs and plates was due to cost, but increased the ability for bacteria and viruses to live longer on such surfaces.
Poor cleaning of stainless surfaces in hospitals is directly related to the spread of Mersa Virus in patients.
Mersa can live on stainless surfaces for 6 hours. Stainless infused with 10% copper ensures Mersa cannot survive more than half an hour. That was a study done years ago.
IIRC, there was a story a century or two ago about how a doctor noticed that coppersmiths in Paris were miraculously spared some widespread pathogen that had infected essentially everyone in their neighborhood except them.
Silver has been used as an antibacterial, antifungal and antiviral remedy for centuries. Although microbial science didn’t exist, dropping a silver coin in milk was known to keep it fresh longer. Silver dust was known to prevent wounds turning putrid. I make and use colloidal silver. Any time I have a cut ot scrape, a sore throat or an irritated eye, I simply spray colloidal silver. I also use colloidal silver in a nebulizer for chest cold onset. Twice daily since the Wuhan Virus outbreak.
Fascinating! Happy Easter to all my Christian pals!