A patient adjusts his face mask as he leaves a COVID-19 vaccination site inside the Jacob K. Javits Convention Center, Wednesday, Feb. 3, 2021, in the Manhattan borough of New York. (AP Photo/John Minchillo)

A patient adjusts his face mask as he leaves a COVID-19 vaccination site inside the Jacob K. Javits Convention Center, Wednesday, Feb. 3, 2021, in the Manhattan borough of New York. (AP Photo/John Minchillo)

U.S. CDC study finds two masks are better than one vs. COVID-19

When both exhaling and inhaling heads were double-masked, more than 95% of the particles were blocked

U.S. government researchers found that two masks are better than one in slowing coronavirus spread, but health officials stopped short of recommending that everyone double up.

The Centers for Disease Control and Prevention on Wednesday reported the results of a lab experiment that spaced two artificial heads 6 feet from each other and checked to see how many coronavirus-sized particles spewed by one were inhaled by the other.

The researchers found that wearing one mask — surgical or cloth — blocked around 40% of the particles coming toward the head that was breathing in. When a cloth mask was worn on top of a surgical mask, about 80% were blocked.

When both the exhaling and inhaling heads were double-masked, more than 95% of the particles were blocked, said the CDC’s Dr. John Brooks.

Still, for now, health authorities acknowledge they have their hands full just trying to get more people to wear one mask and wear it correctly.

“The first challenge is to get as many as people as possible masking. And then for those that do mask, to help them get the best benefit out of that mask,” Brooks said.

Brooks said agency officials heard about people donning two masks and wanted to evaluate whether it was beneficial.

The study had many limitations: The researchers used one brand of surgical mask and one kind of cloth mask, and it’s not clear if results would be the same with every product. But it echoes some earlier research that suggests two masks are better than one.

“It works,” Brooks said.

The CDC updated its guidance, saying people can wear a cloth mask on top of a disposable surgical mask “for better fit and extra protection.” If done correctly, the combination can tighten the gaps around the mask’s edges that can let virus particles in, the CDC said.

The agency also said it will take down a make-your-own mask page, which went up last year when masks were in short supply and the CDC was encouraging people to take steps to interrupt viral transmission.

Some Americans have already started doubling up. Experts believe that’s at least partly out of concern about new strains of coronavirus that have been found to spread more easily than the one that has driven the U.S. epidemic for the past year

CDC guidance has evolved over the course of the epidemic.

Mask-wearing has long been common in some countries during respiratory outbreaks, especially in parts of Asia, but not in the United States.

When the COVID-19 crisis began and masks disappeared from store shelves, U.S. health officials actively discouraged the general public from wearing them. “Seriously people – STOP BUYING MASKS!” then-Surgeon General Jerome Adams wrote in a tweet almost a year ago.

Two months later, after it became clear that infected people who did not exhibit symptoms could spread the virus, the CDC began recommending people wear masks in public.

READ MORE: Threat from variants means provinces must be ready to lock down again quickly: Tam

Mask-wearing increased and some places enforced mask mandates, but many Americans continue not to wear them. A recent University of California survey suggested that only about half of U.S. adults wear masks when in close contact with people outside their household.

Discussions about double-masking and higher-quality masks are important, said Dr. Isaac Bogoch, an infectious diseases scientist at the University of Toronto.

“But if a significant proportion of your populations isn’t wearing a mask in the first place, then you’re having the wrong conversation,” he added.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Mike Stobbe, The Associated Press


Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Coronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

COVID
Red Deer down to 313 active cases of COVID-19

Alberta reports an additional 411 COVID-19 cases

Pictured here is Stettler’s Jenner Smith with a guide dog from Aspen Service Dogs. An online auction will be running soon to help raise funds for Jenner to receive his very own service dog later this year. Jenner, who is four years old, was diagnosed with Autism Spectrum Disorder in 2019. photo submitted
An online auction is planned to raise funds for a service dog for a Stettler family

Jenner Smith, four, was diagnosed with Autism Spectrum Disorder in 2019

THE CANADIAN PRESS/Alex Panetta
Economists “cautiously hopeful” for economic recovery in Alberta

Charles St. Arnaud says Alberta’s recovery will rebound along with roll-out of the COVID-19 vaccine

Alberta’s chief medical officer of health Dr. Deena Hinshaw acknowledged that Friday would be one year since the first case of COVID-19 was identified in the province. (photography by Chris Schwarz/Government of Alberta)
Three more Red Deer COVID-19 deaths, 331 active cases in Alberta

Red Deer is down to 362 active cases of the virus

senior
Stettler Handi-bus is putting out the call for more community support

Medical van for out of town trips hasn’t been running since Jan. 1st, 2021

Caitlin Kraft, the sister of Jeffery Kraft, stands third from the left, holding a sign calling for the maximum sentence for Campbell, who is charged with manslaughter. (Photo by Paul Cowley)
UPDATED: Judge again rejects submission of 7-year sentence for slaying of Kraft

Tyler John Campbell charged with second-degree murder for December 2019 homicide

Supporters rally outside court as Pastor James Coates of GraceLife Church is in court to appeal bail conditions, after he was arrested for holding day services in violation of COVID-19 rules, in Edmonton, Alta., on Thursday March 4, 2021. THE CANADIAN PRESS/Jason Franson
‘Law remains valid:’ Pastor accused of violating health orders to remain in jail

The Justice Centre for Constitutional Freedoms is representing the pastor

A decommissioned pumpjack is shown at a well head on an oil and gas installation near Cremona, Alta., Saturday, Oct. 29, 2016. The Alberta Energy Regulator says it is suspending all of the licences held by an oil and gas producer with more than 2,200 wells and 2,100 pipelines after it failed to bring its operations into compliance. THE CANADIAN PRESS/Jeff McIntosh
Alberta Energy Regulator suspends licences of oil and gas producer that owes $67M

The company is being asked to comply with past orders to clean up historic spills and contamination

Prime Minister Justin Trudeau holds a press conference in Ottawa Friday, March 5, 2021. THE CANADIAN PRESS/Sean Kilpatrick
Trudeau holds firm on premiers’ health-care funding demands, COVID-19 aid comes first

Premiers argue that the current amount doesn’t keep pace with yearly cost increases of about five per cent

Seniors in the 65-unit Piper Creek Lodge are among those waiting for COVID-19 vaccinations. (File photo by Advocate staff)
Central Alberta senior lodges anxiously waiting for COVID-19 vaccinations

“Should be at the front of the line, not the back of the line”

Walter Gretzky father of hockey hall-of-famer Wayne Gretzky waves to fans as the Buffalo Sabres play against the Toronto Maple Leafs during third period NHL hockey action in Toronto on Tuesday, Jan. 17, 2017. THE CANADIAN PRESS/Nathan Denette
Walter Gretzky, father of the Great One, dies at 82

Canada’s hockey dad had battled Parkinson’s disease and other health issues

This Dec. 2, 2020 photo provided by Johnson & Johnson shows vials of its Janssen subsidiary’s COVID-19 vaccine in the United States. THE CANADIAN PRESS/AP-Johnson & Johnson via AP
Canada approves Johnson & Johnson’s 1-shot COVID-19 vaccine

It is the 4th vaccine approved in Canada and the 1st that requires just a single dose

(AP Photo/Richard Vogel, File)
Pandemic stress, isolation key factors as to why Canadians turned to cannabis, alcohol

Study found that isolation played key role in Canadians’ substance use

Most Read