The Atlanta Journal-Constitution
Copper won’t save you from coronavirus
Will copper keep the coronavirus at bay?
In recent months, there’s been a surge of interest in materials laced with copper, including socks, bedsheets and coatings that can be sprayed onto surfaces. Multiple companies are marketing face coverings and masks with built-in copper linings, touting their germ-killing properties. One company even offers a “nasal wand” designed to apply “the touch of solid copper” to the hands, face and nostrils at the first sign of illness.
But while copper does have antimicrobial qualities, microbiologists say you should think twice before buying into many of these products’ claims.
What copper might do to pathogens
People have been aware of copper’s sanitizing abilities at least as far back as ancient Egypt, said Karrera Djoko, a biochemist and microbiologist at Durham University in England.
“Even before we had a concept of what a germ is,” Djoko said, “we were using copper to contain water” and keep it safe to drink.
Scientists today know the mighty metal as a swift slayer of microbes, capable of limiting the spread of E. coli, salmonella, influenza virus and more. In certain settings, it may stifle the coronavirus, too. In a study in the New England Journal of Medicine, researchers reported that, under controlled laboratory conditions, the coronavirus couldn’t last more than a few hours on copper surfaces, compared with a couple of days on stainless steel or plastic.
For humans, copper is an essential nutrient, which you easily get enough of in a typical diet. But Djoko said many microbes don’t take to copper so kindly. When copper physically contacts a germ like coronavirus, it can release reactive ions that pummel and puncture the bug’s exterior. That gives the ions access to the microbe’s innards, where they wreak similar havoc on its genetic material.
Usage in masks
What works well in the lab, however, won’t necessarily pass muster in the real world. Djoko has held off on recommending copper-infused accessories, including face coverings and masks, as a way to reduce transmission.
Loosefitting face coverings, like cloth or surgical masks, aren’t airtight and don’t make the wearer impervious to infection. But if the wearer is infected, masks can do a great deal to protect others from virus-laden droplets. A 2010 study found that the metal-laced accessories could curb the amount of active influenza virus lingering on contaminated masks. (The analysis was conducted by Cupron Scientific, one of several companies now selling copper-lined face coverings.)
Still, not all metal-infused masks are created equal. Manufacturers would need to design them with enough copper — ideally near the product’s surface — to actually do the job.
“If your mask is only 1% copper, that means it’s 99% not copper,” Djoko said. If the metal and microbe don’t physically meet, the mask “won’t confer any more benefit than just regular masks.”