A Blog by Jonathan Low


Jan 28, 2021

The Reason Covid Double-Masking Is Becoming A Trend

As Covid vaccination gets closer, no one wants to be the last person infected. 

And news about the variants from the UK, Brazil and South Africa during the particularly dangerous winter months are causing more people to use two masks when going out in public, to be even more sure. JL

 Sandee LaMotte reports in CNN:

A single-layer mask isn't really effective in blocking aerosols and even homemade two- and three-ply fabric masks are only partially protective, somewhere in the 50% to 60% range of effectiveness. "Put a surgical mask under a cloth mask and you get "over 91% removal efficiency for particles."

Layering your face is in -- but not as a fashion statement. It may just save a life.

Public health officials are suggesting double masking as a way to increase the level of protection from the coronavirus and its multiple, more contagious variants.
"If you have a physical covering with one layer, you put another layer on, it just makes common sense that it likely would be more effective, and that's the reason why you see people either double masking or doing a version of an N95," Dr. Anthony Fauci, now chief medical adviser to President Joe Biden, told NBC's Savannah Guthrie. Biden and Vice President Kamala Harris have been doubling up for weeks -- in fact Biden was often seen with a surgical mask under his go-to black fabric covering before being sworn into office.
On Inauguration Day, transportation secretary nominee Pete Buttigieg and his husband, Chasten Buttigieg, took a selfie double masking, and inaugural poet Amanda Gorman wore a surgical mask beneath her Prada version.
Republican US Sens. Mitch Romney and Marco Rubio were seen sporting double masks on Capitol Hill in mid-December.

Layer on the protection

A single-layer mask isn't really effective in blocking aerosols, studies show, and even homemade two- and three-ply fabric masks are only partially protective -- somewhere in the 50% to 60% range of effectiveness.
Surgical masks, also called medical-grade masks, are made of three layers of nonwoven fabric typically made from plastic. The colored top layer of fabric is made of medical-grade spunbond polypropylene, which is a resin polymer heat-bonded into a weblike structure.
A 2020 study found surgical masks were about 50% effective at protecting the wearer from other people's aerosols and between 60% and 70% effective at protecting others.
But put a surgical mask under a cloth mask and you get "over 91% removal efficiency for particles," said Joseph Allen, an associate professor at the Harvard T.H. Chan School of Public Health and the director of the school's Healthy Buildings program, in a recent interview.
In mid-December, Linsey Marr, a professor of civil and environmental engineering at Virginia Tech who is a leading expert in aerosol transmission of viruses, and Dr. Monica Gandhi, a professor of medicine at UCSF/San Francisco General Hospital, published a commentary calling for double masking,
"For maximal protection," Marr and Gandhi suggested the public could "wear a cloth mask tightly on top of a surgical mask where the surgical mask acts as a filter and the cloth mask provides an additional layer of filtration while improving the fit."
A second option, they said, could be to wear a three-layer mask made from a flexible, tightly woven fabric that conforms to the face, with an insert of a "non-woven high-efficiency filter material," such as a vacuum bag.
Of course, the best facial coverings for protection are the N95-type respirators, made from fibers woven with an electrical charge that can trap errant particles, much like a sock that sticks to a blanket in the dryer. Similar products include the Chinese KN95, the European FFP1 and FFP2 versions, the Australia-New Zealand P2, the Korean 1st Class and the Japanese DS2.
"Consider upgrading from a cloth mask to a surgical mask, or from a surgical mask to an N95/KN95/equivalent if available. Better masks may help reduce risk from more-contagious strains," former US Centers for Disease and Control director Dr. Tom Friedan tweeted Monday.
But the CDC isn't currently recommending N95 masks for the general public, partly due to a shortage of the masks for health care workers, and also due to concerns that people will tolerate the masks, which can hinder breathing.
"I worry that if we suggest or require that people wear N95's they won't wear them all the time," Dr. Rochelle Walensky, the new head of the CDC told CNN's Anderson Cooper and Chief Medical Correspondent Dr. Sanjay Gupta in a town hall Wednesday.
"They're very hard to breathe in when you wear them properly," Walensky said. "They're very hard to tolerate when you wear them for long periods of time."

Proper wear and care of your mask

Whatever mask you wear, be sure to do so properly -- including while double masking. No uncovered noses are allowed. Both masks should go over the bridge of the nose, below the chin and be flush on the face, resting along the skin, experts say.
When you choose your cloth mask, you shoud look for a tight weave, according to studies. Use the light test to check the weave: If you can easily see the outline of the individual fibers when you hold up the mask to the light, it's not likely to be effective.

And be sure to clean and dispose of your masks properly. Surgical masks are one-time use only, and if they are soiled or breathing becomes difficult, the mask should be carefully discarded and replaced, the FDA said.
The CDC recommends storing any dirty fabric masks in sealed plastic bags until you can wash them.
"Wash wet or dirty masks as soon as possible to prevent them from becoming moldy. Wet masks can be hard to breathe through and are less effective than dry masks," the CDC says.
Dry your mask completely in a warm or hot dryer, the CDC says, or by hanging it "in direct sunlight to dry completely. If you cannot hang it in direct sunlight, hang or lay it flat and let it dry completely."


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