ARIZONA — Masks have become a cultural flashpoint, in the long shadow of the pandemic.
Masks – or the lack of masks – have spurred bitter arguments in the checkout lines, attacks on store clerks, defiance by small-town mayors, fashion statements and political rants.
Nonetheless, doctors, governors and the federal Centers for Disease Control now urge everyone wear masks in public – especially if they can’t stay six feet apart.
So how did advice from doctors become so controversial?
Why did the US Surgeon General initially warn people not to wear masks?
Most importantly — will widespread mask-wearing blunt the frightening second wave of infections now plaguing Arizona and much of the West and South?
Short answer to that last crucial question?
A growing body of research suggests that widespread mask wearing by the healthy and the sick alike can slow down the spread of the virus as effectively as closing businesses and rarely leaving the house.
In fact, one recent study concluded that mandatory face mask orders issued in 15 states may have already reduced the total number of infections by 300,000 or 400,000. Studies show that widespread mask wearing could have just as big an impact on slowing the spread of COVID-19 as the shutdown of schools and businesses and the stay-at-home orders that have caused such economic carnage.
So why has the message changed from the early days of the pandemic when the US Surgeon General said people shouldn’t rush out and buy masks already in short supply for doctors and nurses?
Mostly, this is because doctors have discovered that people who aren’t coughing, sneezing, feverish or in any way symptomatic can still spread the virus. In fact, perhaps as many as 40 percent of those infected never develop noticeable symptoms, but still spread the virus when they breathe or talk. The other 60 percent may be most infections a day or two before symptoms develop.
That conclusion has emerged from a growing body of research, both in the real world and in the laboratory. As a result, near-universal mask wearing in public remains one of the best ways to slow the spread of the virus and buy time, while doctors continue to search feverishly both for effective treatments and vaccines.
That doesn’t mean people in masks can safely gather in big crowds or ignore social distancing rules. But the combination of social distancing and wearing a mask provides the best protection from a virus that spreads mostly through the air, according to the research.
Masks work because the virus spreads mostly in microscopic, airborne droplets. People who are infected breath out these droplets constantly, with the viral load and range increasing when we talk, cough, sing or shout. Fortunately, cloth masks made of a finely woven fabric stops most of those droplets, even if the mesh of the cloth is larger than the virus itself. To spread efficiently, the virus must be protected and wafted aloft while riding cocooned in the droplet of moisture. Such droplets can travel 30 feet and linger in an enclosed space for hours.
Some anecdotal evidence suggests wearing a mask can make a dramatic difference in the rate of spread. Of instance, a man infected with COVID-19 flew from China to Toronto. He had a dry cough, but wore a mask on the flight. The 25 people sitting closest to him were all subsequently tested for the virus and none were infected, in CMAJ, a Canadian medical journal.
In another case, two hair stylists in Missouri had close contacts with 140 clients while sick with COVID-19. Everyone wore a mask and none of the clients tested positive, according to the case report published in a medical journal.
Many researchers now argue that the widespread use of masks to cope with air pollution in many Asian cities may account for the much greater success of countries like China, South Korea, Singapore and Japan in containing the virus. China managed to contain the initial outbreak to Wuhan, even as the virus spread to every state in the US. China also contained a second outbreak in Bejing. Many people in urban areas of China already wore surgical masks daily due to the dangerous level of air pollution in China’s major cities.
So here’s a summary of some of the latest research on how COVID-19 spreads and how wearing a mask will make a difference.
“Stay Healthy”: One lab-based study found quietly saying “stay healthy” generates hundreds of droplets ranging from 20 to 500 micrometers, but nearly all those droplets were blocked by covering the mouth with a damp washcloth, according to the study published in the New England Journal of Medicine.
Masks work: Wearing a surgical mask significantly reduced the viral particles emitted in droplets and aerosols by 246 people with the flu or the common cold, according to a study published in NatureMedicine. People wearing masks released about 1,000 particles in 30 minutes while people without masks released about 100,000,000,000 particles.
States compared: A study in Health Affairs found mask mandates in 15 states slowed the spread of the virus, compared to 15 states without such a statewide mandate. The mandate slowed growth by 1 percent immediately and 2 percent over the first three weeks. That doesn’t sound like much, but it was likely enough to reduce the total number of infections by as much as 450,000 in the 15 states.
Countries compared: Countries in which most people wore masks in public had a much lower rate of spread of COVID-19, according to a study of 198 countries published in ResearchGate. In countries with “government policies” or “cultural norms” supporting widespread mask wearing practices deaths increased by 8 percent per week, compared to 54 percent in similar countries where people generally didn’t wear masks. The average of the population, obesity rates and curtailment of international travel also affected the mortality rate. Lockdowns, testing rates and contact tracing also had an impact on mortality rates, but much less than mask-wearing.
80 percent: If 80 percent of people wore masks in public it would slow the spread of the disease more than a strict lockdown according the results of a computer modeling program based on research on the effectiveness of various interventions, according to an international study by researchers from UC Berkeley, Cambridge and elsewhere. The study suggested that if 80 percent of people reliably wear masks in public it slows the spread of the virus by 60 percent. However, if fewer than 50 percent of people wear masks, it has little impact on the overall spread. The computer projection concluded effective social distancing after lockdowns end would eventually produce 1.1 million deaths in the US. An indefinite lockdown would produce 180,000 deaths. Masking levels of 50 percent after lockdowns end would produce 240,000 deaths. Masking levels of 80 percent after lockdowns end would produce 60,000 deaths.
Saving lives: Another projection by Health Metrics and Evaluation concluded that if 95 percent of people wear masks in public it would save 33,000 lives by Oct. 1.
Cloth masks work: Surgical masks and cloth masks with a triple-layer, fine woven cloth work almost as well as custom fitted, N95 surgical masks for non-medical personnel outside the hospital, according to a study by engineers from Northeastern University. The homemade cloth masks tested removed 38 to 96 percent as many viral particles as surgical maps. However, more crude masks like simply wearing a bandana or even a face shield that doesn’t make contact with the face around the mouth and nose were ineffective.
Masks slash infections: A Texas A&M study concluded that face mask use in New York from April 17 to May 9 reduced cases by 66,000. In Italy from April 6 to May 9, masks reduced infections by 78,000. The authors – including Nobel prizewinning atmospheric chemist Mario Molina from US San Diego, concluded mask-wearing can do more to stop the spread of the virus than hand washing or social distancing – although they still urged the public to practice those measures. The research has come under fire after publication in the scientific journal PNAS for statistical methods that potentially.