In 2020, it was reported that when the novel coronavirus responsible for Covid-19 landed on glass or stainless steel, it lasted for several days, whereas when it landed on copper, it died in a matter of hours.
As impressive as that sounds, some researchers were amazed that it even lasted that long as earlier coronaviruses succumbed within minutes of landing on the metal. And it’s not just coronaviruses that copper works its antimicrobial magic on, with studies showing it effective in mere minutes against the likes of the bacterium Legionella pneumophila (that causes Legionnaire’s disease, H1N1 (swine flu), and even the drug-resistant Staphylococcus aureus which can cause infections of the skin, lungs, and blood.
Copper (which takes its name from the Latin, Cuprum, in reference to the island of Cyprus where the Romans mined it, and hence its chemical symbol, Cu) is not the only heavy metal with antimicrobial properties – gold and silver, for example, have them too – but its atomic makeup gives it a disinfecting edge. When landing on the surface of a heavy metal, bacteria and viruses are pummelled by electrically charged ions that cause cell damage and prevent mutation. Unlike gold and silver, copper also possess a free electron, which, according to Michael G. Schmidt, a professor of microbiology and immunology at the Medical University of South Caroline, acts as “molecular oxygen grenade”, increasing its reactivity – and lethality – to germs. Schmidt tells Smithsonian that copper’s “truly a gift from Mother Nature”.
Incredibly, copper’s healing properties were appreciated way before humans knew anything about microbes, referenced in Smith’s Papyrus, an Ancient Egyptian medical document – and history’s oldest known one. Though the document was written around 1600 BC, the hieroglyphic symbol that denotes copper implies that it may have been used as a disinfectant for a good 1,500 years prior.
Also around 1600 BC, the Chinese were placing copper coins around their bodies to alleviate various aches and pains, while other ancient civilisations were known to have used copper cups to help cleanse drinking water and others to use shavings from bronze (an alloy of copper, predominantly, mixed with the likes of tin and zinc) swords to cleanse battlefield wounds. Tests have also shown that copper’s antimicrobial properties last for many years; perhaps even indefinitely.
Another characteristic that copper shares with gold is colour. Few metallic elements are anything other than silver or grey, whereas copper’s natural hue leans towards orange, turning a more reddish colour with exposure to air (and eventually blue-green with corrosion). Copper is beautiful as well as medicinal. Little wonder, then, that its first purpose was that of decoration. A pendant dug up in modern-day northern Iraq dates back around 8700BC, meaning copper was discovered at least 10,000 years ago – around 4,000 years before the discovery of gold – and likely making it human’s oldest metal.
Copper’s near-indestructibility combined with its recyclability also makes it one of the most sustainable building materials out there.
“It’s just such a warm material,” says Mount Maunganui copperworker and artist Tony ‘Copper Poppa’ Barnett, who discovered his love of copperworking using leftover and unwanted scrap through his other life as a plumber (copper was, of course, famously utilised by Romans in their legendary plumbing systems).
“It’s beautiful to touch, it’s basically soft, it glows, and it goes together with other materials really well.”
Throughout human history, civilisations from East Asia through to Europe and South America were spellbound by the metal’s beauty and malleability, fashioning it into all manner of jewellery and decorations. The Ancient Egyptians also used it to make razors, weights, and balances, and to adorn obelisks and temples. Aesthetic appeal aside, copper is a useful building material because it’s not just tough – it gets more durable with time.
While iron and its alloys rust – and weaken – through oxidisation, when the same reaction occurs on copper, it develops a layer of copper carbonate on the surface known as patina. This new blue-green skin not only lends the structure a unique and beautiful appearance, but further protects the copper from the elements for centuries, and in some cases, millennia. Famous examples include New York’s Statue of Liberty, the domes of Berlin Cathedral, and the roof of Belvedere Palace in Vienna.
More recent buildings include the Macon City Auditorium in Macon, Georgia, which has one of the world’s largest copper roofs, and the Museum of Fire, Żory, Poland, designed to resemble dancing flames (and treated with a high-powered varnish to prevent patina to keep it flame-like). Boston’s Museum of Medical History and Innovation at Massachusetts General Hospital was even built using handcrafted recycled copper cladding.
Copper’s near-indestructibility combined with its recyclability makes it one of the most sustainable building materials out there also. As Tony knows all too well, sourcing his material from scrap dealers and friends in the plumbing trade.
“You have the likes of these beautiful old hot water cylinders with gorgeous patina that would likely end up flattened and sent off to China,” says the coppersmith who makes everything from artworks to kitchen splashbacks to plant pots and door panels. “But it’s so beautiful, with so many possibilities. And it’s such a forgiving material, my workshop doesn’t even have power – all my work’s all done by hand.”
