It began in mid-March. Every time Michael D. L. Johnson checked his email, the University of Arizona microbiologist would find a new batch of messages, all asking the same question: Will products made with copper keep the coronavirus at bay?
“I was getting three to four emails about it a day,” Dr. Johnson said. Some asked if he recommended ingesting copper as a cure. Others wondered if it was a good idea to outfit their homes with it. A few inquisitive citizens even wanted to know whether wearing copper accessories, such as bracelets, would stave off disease.“It was kind of a wild ride,” Dr. Johnson said.The flood of missives in his inbox eventually waned. But in many ways, the Covid-19 copper craze has not. In recent months, there’s been a surge of interest in materials laced with the metal, 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, Dr. Johnson and others said you should think twice before buying into many of these products’ claims.What copper might do to pathogensPeople 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,” Dr. 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 days on stainless steel or plastic. (Though scientists don’t think surfaces are the main way the virus spreads between people.)For humans, copper is an essential nutrient, which you easily get enough of in a typical diet. But Dr. 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.Joanna Jablonska, left, and Szymon Caluch, scientists at the Jacob of Paradies University in Gorzow Wielkopolski, Poland, working with colloidal silver and copper to make a disinfectant.Credit…Lech Muszynski/EPA, via ShutterstockCopper can be calamitous for microbes in other ways as well, Dr. Johnson said. Metal ions, like iron or zinc, are found in about 40 percent of proteins with known structures, and most likely play essential roles in their function. But in a vicious game of musical chairs, copper that finds its way into a cell or a virus can swoop in and displace other metals, impairing or even destroying the proteins it commandeers.“If 40 percent of your proteins don’t work, you don’t work,” Dr. Johnson said. Copper may even be capable of jamming up proteins that typically run metal-free by simply glomming onto their surfaces.Even our own immune systems appear to exploit copper’s protective perks. Some evidence suggests that immune cells like macrophages — which gobble up and destroy bacteria, viruses and other microbes — may be capable of engulfing and sequestering germs in an acidic “ball of death” chamber that’s then spiked with lethal doses of copper, Dr. Johnson said. “Our bodies have been using this for warfare” long before copper masks hit the market, he added.But it remains to be seen which of these scenarios will play out with the coronavirus, and to what extent. Dr. Johnson is one of several scientists currently on the case, tinkering with copper to suss out exactly how it exerts its apparently potent effects on this dangerous germ.[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]Steer clear of the copper nose pickerWhat works well in the lab, however, won’t necessarily pass muster in the real world. Both Dr. Johnson and Dr. Djoko have held off on recommending copper-infused accessories, including face coverings and masks, to their friends, family and colleagues as a way to reduce transmission. (Overingesting copper is also a bad idea, and probably wouldn’t do much to boost immunity, Dr. Johnson said. And Dr. Djoko isn’t keen on the idea of sticking copper wands up your nose.)Loosefitting face coverings, like cloth or surgical masks, aren’t air tight 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 spewed by coughs, sneezes and speech. 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.)If copper face coverings also curtail the coronavirus, that could come in handy for people who mishandle their masks, said Linsey Marr, an aerosol scientist at Virginia Tech. A hefty dose of copper could diminish the chances of viable virus making it into the eyes, nose or mouth via a wayward hand that’s touched the front of a mask.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 percent copper, that means it’s 99 percent not copper,” Dr. Djoko said. If the metal and microbe don’t physically meet, the mask “won’t confer any more benefit than just regular masks.” The Coronavirus Outbreak Frequently Asked Questions and Advice Updated June 16, 2020 I’ve heard about a treatment called dexamethasone. Does it work? The steroid, dexamethasone, is the first treatment shown to reduce mortality in severely ill patients, according to scientists in Britain. The drug appears to reduce inflammation caused by the immune system, protecting the tissues. In the study, dexamethasone reduced deaths of patients on ventilators by one-third, and deaths of patients on oxygen by one-fifth. What is pandemic paid leave? The coronavirus emergency relief package gives many American workers paid leave if they need to take time off because of the virus. It gives qualified workers two weeks of paid sick leave if they are ill, quarantined or seeking diagnosis or preventive care for coronavirus, or if they are caring for sick family members. It gives 12 weeks of paid leave to people caring for children whose schools are closed or whose child care provider is unavailable because of the coronavirus. It is the first time the United States has had widespread federally mandated paid leave, and includes people who don’t typically get such benefits, like part-time and gig economy workers. But the measure excludes at least half of private-sector workers, including those at the country’s largest employers, and gives small employers significant leeway to deny leave. Does asymptomatic transmission of Covid-19 happen? So far, the evidence seems to show it does. A widely cited paper published in April suggests that people are most infectious about two days before the onset of coronavirus symptoms and estimated that 44 percent of new infections were a result of transmission from people who were not yet showing symptoms. Recently, a top expert at the World Health Organization stated that transmission of the coronavirus by people who did not have symptoms was “very rare,” but she later walked back that statement. What’s the risk of catching coronavirus from a surface? Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks. How does blood type influence coronavirus? A study by European scientists is the first to document a strong statistical link between genetic variations and Covid-19, the illness caused by the coronavirus. Having Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator, according to the new study. How many people have lost their jobs due to coronavirus in the U.S.? The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April. Will protests set off a second viral wave of coronavirus? Mass protests against police brutality that have brought thousands of people onto the streets in cities across America are raising the specter of new coronavirus outbreaks, prompting political leaders, physicians and public health experts to warn that the crowds could cause a surge in cases. While many political leaders affirmed the right of protesters to express themselves, they urged the demonstrators to wear face masks and maintain social distancing, both to protect themselves and to prevent further community spread of the virus. Some infectious disease experts were reassured by the fact that the protests were held outdoors, saying the open air settings could mitigate the risk of transmission. My state is reopening. Is it safe to go out? States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people. What are the symptoms of coronavirus? Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days. How can I protect myself while flying? If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.) How do I take my temperature? Taking one’s temperature to look for signs of fever is not as easy as it sounds, as “normal” temperature numbers can vary, but generally, keep an eye out for a temperature of 100.5 degrees Fahrenheit or higher. If you don’t have a thermometer (they can be pricey these days), there are other ways to figure out if you have a fever, or are at risk of Covid-19 complications. Should I wear a mask? The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing. What should I do if I feel sick? If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others. How do I get tested? If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested. Durability could also be an issue, especially if copper masks are getting repeatedly washed or disinfected. Many common household cleaners are formulated with compounds that could strip copper ions off a protective surface, Dr. Djoko said.Still, copper may yet have a role to play in the pandemic. Installing copper-based surfaces in hospitals has been shown to cut down on transmission rates of certain pathogens, including antibiotic-resistant strains of bacteria. Dr. Djoko thinks it could keep coronavirus in check in such settings, too.But all experts emphasize that having the metal around doesn’t let anyone off the hygiene hook. Copper on its own is no cure-all — and its effects aren’t instantaneous. It takes about 45 minutes for copper to reduce the amount of virus on a surface by half.“It’s not like it hits the copper and poof, it’s gone,” said Dr. Marr. So you might want to keep that in mind before you buy a copper or brass tool for using touch screens and opening doors. To minimize transmission risk, people should still wash their hands, avoid crowds and maintain a safe distance from one another.More copper-containing accouterments — coronavirus-related or not — may yet be headed our way. Dr. Johnson has nothing against that.“Copper is a fantastic fashion choice,” he said. “You’re going to look fabulous. It just might not work the way you think.”