Masks matter: How we know face coverings slow the spread of COVID-19 – Las Vegas Sun

§ July 9th, 2020 § Filed under Nanotechnology Journal Comments Off on Masks matter: How we know face coverings slow the spread of COVID-19 – Las Vegas Sun


By Emma Cauthorn

Thursday, July 9, 2020 | 2 a.m.

A simple cloth face mask can help prevent the spread of COVID-19, and in doing so, contribute to the safe reopening of our city and state while potentially saving lives

On June 24, Gov. Steve Sisolak issued a mandatory face-covering policy in public spaces for all Nevadans and visitorsin line with current Centers for Disease Control and Prevention and World Health Organization guidelinesbut the directive has been met with some resistance. Heres what you need to know about the importance of wearing masks.

Why masks work

In the early months of the pandemic and before much was known about the novel coronavirus, public health officials stated that it wasnt necessary for the general population to wear cloth masks. The thought at the time was that medical-grade N95 respirators were the only effective face covering against the virusbut the PPE shortage meant those masks were not easily accessible and should be strictly reserved for health care professionals. The WHO suggested that cloth masks were only necessary for those who had symptoms of COVID-19 and their caregivers. By April, however, the CDC began recommending cloth masks for everyone, and in June, the WHO followed suit

What changed? We know more about how the disease is spread today than we did six months ago.

According to the CDC, recent studies indicate that a large portion of people with COVID-19 are asymptomaticresearchers at Stanford Medicine report that this might be true for up to 40% of those infected. This is an important thing to understand when considering mask usage, because a large portion of the population can spread COVID-19 and never show symptoms themselves.

While a cloth face covering might not protect the wearer like an N95 mask will, it may keep the wearer from spreading the virus to others. So if everyone is wearing masks, well be able to limit transmission rates.

Wearing a face mask helps to intercept particles and keep them out of the air, explains Dr. G. Rodney Buzzas, chief medical officer at Dignity Health-St. Rose Dominican, Siena and Rose de Lima Campuses. These particles are created and spread not only by coughing or sneezing, but also by talking, laughing and even breathing. The COVID virus is known to travel and be passed through these particles.

Because so many people might be infected with COVID-19 and never feel sickor may be pre-symptomaticseemingly innocuous and casual social interactions can spread the disease rapidly.

How we know masks work

Theres a growing body of evidence that demonstrates the efficacy of cloth face masks. A recent study published in peer-reviewed healthcare journal Health Affairs compared the growth rate of COVID-19 before and after mask mandates in 15 states and the District of Columbia. They found the disease growth rate slowed daily. During the first five days, the daily growth rate slowed 0.9 percentage points, and at three weeks, it had slowed a full 2 percentage points.

The CDC advises that N95 respirators and surgical masks are critical supplies that should be reserved for health care workers and first responders.

Researchers at Virginia Commonwealth University evaluated COVID-19 deaths across 198 different countries and found that those with cultural norms or government policies about wearing masks had lower death rates.

One study published in peer-reviewed medical journal Nature Medicine analyzed people who had the flu or the common cold and found that wearing a surgical mask significantly reduced the amount of respiratory viruses emitted in droplets.

An experiment published by the New England Journal of Medicine used a high-speed video camera to determine that hundreds of droplets, ranging from 20 to 500 micrometers, are generated when someone says a simple phrase, and nearly all of them were blocked when the mouth was covered with a damp washcloth.

And the University of California San Francisco analyzed a wide variety of different studies to conclude wearing masks was effective at protecting the general population.

As we continue to venture into the phases of reopening, its more important than ever to wear a mask in public spaces. Wearing a mask protects others from the person wearing the mask, says Dr. Clarence M. Dunagan, chairman of emergency services and facility medical director at MountainView Hospital. During this pandemic, making everyone wear masksespecially when inside or close togetherwill hopefully drastically decrease the spread of the virus. Id much rather be required to wear a mask in public for the protection of others instead of another stay-at-home quarantine order being issued, which no one wants.

Who shouldnt be wearing masks?

The CDC states that cloth face coverings should not be worn by children under the age of 2 or anyone who has trouble breathing, is unconscious, incapacitated or otherwise unable to remove the mask without assistance.

Tips for effective cloth masks

Researchers at Stanford Medicine, who conducted the study that helped shape WHO guidelines about mask wearing, recently published an article in peer-reviewed journal Nanotechnology Letters assessing the filtering and breathability of different fabrics often used to make masks. Here are some of their recommendations:

Masks are considered most effective at stopping the spread when combined with other healthy practices, such as frequent hand washing and social distancing.

Cloth masks should feature at least three layers of different materials.

The outer layer should be made of a fabric thats at least somewhat water resistant. (It can be a combination of cotton and polyester, nylon or rayon.)

The middle layer should either be polypropylene or three-ply disposable facial tissues.

The inner layer should be a wicking material, like 100% soft cotton, to draw moisture away from the face.

A mask should not fit so tightly that its too uncomfortable to wear, but it should sit against the skin all the way around from the middle of your nose to under your chin and almost to your ears. It should not gape when you move your head or speak.

Masks should be treated with care. Dont share them with others, and keep them in sealed plastic bags when not in use. Wash them regularly, and when you remove them, do so in a way that doesnt spread germs from the front of the mask to your face. Wash hands after touching the mask.

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Masks matter: How we know face coverings slow the spread of COVID-19 - Las Vegas Sun

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