An employee of the Montreal metro offers free masks to traveller on July 13, 2020 (AFP / Eric Thomas)

Post making false face mask claims circulates in Canada and the US

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A Facebook post shared thousands of times in Canada and the United States lists alleged risks associated with the use of face masks that are aimed at curbing the spread of the coronavirus, including decreased oxygen intake and increased “toxic inhalation.” But experts say the claims in the post, and others making similar assertions, are false.

“FACE MASK SAFETY, KNOW THE FACTS BEFORE YOU WEAR ONE,” says the headline of a flyer pictured in the post, which has been shared more than 3,000 times in Canada since July 7, 2020 and lists six negative alleged effects of wearing face masks.

It was also shared on Facebook and Instagram in the United States.

Screenshot of the post taken on July 16, 2020

The Canada post was published on the same day that the City of Toronto made wearing face coverings mandatory in indoor public places and five days after they became mandatory on public transport in the city.

Dr. Theresa Tam, Canada’s Chief Public Health Officer, has recommended the use of face coverings since May 20, 2020.

Similar posts in French have also been shared hundreds of times in Quebec, as well as France and Belgium

Recommendations or requirements that people use masks in a bid to curb transmission of the novel coronavirus have sparked a major backlash from those who balk at the inconvenience of wearing them or view them as an impingement on their personal freedom.

The flyer shown in the posts seems to have been produced by “Hugs Over Masks Canada,” a group “dedicated to removing the lockdown measures” in the country, according to its website.

The flyer can be found on the group's website alongside a “mask exemption form,” which Doug Ford, the premier of Ontario, described as “fraudulent” and “unacceptable.”

Claim: Masks decrease oxygen intake

The false claim that a mask will decrease oxygen intake has been made in multiple social media posts, including these fact-checked by AFP here, here and here.

Vinita Dubey, Associate Medical Officer of Health at Toronto Public Health, told AFP via email that “in general, a cloth mask does not fit tightly to the face. Air can still go around the mask as well as through the pores in the material,” while acting as a barrier to small virus particles.

Claim: Masks cause toxins to be re-inhaled

The post also falsely claims that “toxins that we normally exhale as we breathe become trapped in the mask and re-inhaled.” 

“We don’t exhale toxins,” said Jean-Luc Gala, Head of Clinic at Saint-Luc University in Brussels, Belgium. “We exhale carbon dioxide.”

"The mask filters the virus, but not molecules. A virus is much larger than a molecule of oxygen or carbon dioxide," Gala explained.

A similar claim, that “contaminants sit within mask fibers, get re-inhaled,” was addressed in this AFP fact check.

Hyo-Jick Choi, assistant professor at the University of Alberta’s Chemical and Materials Engineering Department, said via email that “if the pathogen-carrying droplets (from large droplets to small aerosols) are produced by human activities such as sneezing, coughing, and speaking, then the virus-carrying droplets would have a composition similar to saliva.

“In this case, pathogens on the mask surface may not be easily released from fibers because of the high viscosity of the contaminant.”

Claim: Masks shut down the immune system

This claim that masks shut down the wearer’s immune system is based on the assumptions that wearing a mask “decreases oxygen intake” and “increases carbon dioxide intake,” both of which were shown to be false in this AFP fact check.

“Healthcare workers spend eight hours a day wearing a mask and do not develop secondary infections or health problems,” Yves Coppieters, epidemiologist and public health professor at the Universite Libre de Bruxelles said.

Claim: Masks increases virus risk

Mask wearing “encourages triggering & infection from dormant retro viruses, already in the body,” claims another point in the post.

“This is completely false,” said Gala. “For example, we know that certain leukemias are triggered by retroviruses. However, we have never seen flare ups of the disease in patients after a transplant while they wear masks. It has never been an aggravating factor.”

And Dr. Shelley Payne, director of the LaMontagne Center for Infectious Disease at the University of Texas at Austin, said in an email that “there is no evidence that masks or gloves reduce the normal microbiota or predispose people to opportunistic infections.” 

The claim was also made in the widely shared “Plandemic” video, addressed in this AFP fact check.

Claim: Masks can’t block the novel coronavirus

The post claims that “virologists measure COVID-19 to be 80-49NM in size making the weave of material masks to be the equivalent of a chain link fence to a mosquito.”

But COVID-19 is the name of the disease caused by the novel coronavirus, and the claim is also false if applied to the virus itself.

“Surgical masks have a filtering capacity for 90 percent for microorganisms, including (the virus). For FFP2 masks used in intensive care, this capacity increases to 98 percent, 99 percent. For fabric masks, it is lower, estimated to be between 50 percent and 70 percent,” Coppieters said.

This is confirmed by guidelines set out by the Canadian government for the production of masks and respirators.

Claim: Effectiveness of masks has not been studied

“No peer-reviewed studies have been carried out of mask effectiveness within a social environment,” says the final claim in the post. This is unfounded.

Gala said: “This is like saying you blame us for not studying the effectiveness of parachutes in a social environment.”

“We know that parachutes will help you land unscathed, so we’re not going to drop a person with a parachute and one without to compare the effectiveness! We’re talking about a device which we know, empirically, is protective,” he said.

The US Centers for Disease Control and Prevention (CDC) published this study of two hair stylists in Missouri who had tested positive for COVID-19 and carried on working for several days while wearing face masks.

They came into contact with 139 clients, 67 of whom tested negative while the rest did not present symptoms. The CDC concluded that masks helped to mitigate the spread of the virus in a social setting.

AFP Fact Check has debunked more than 560 examples of false or misleading information about the novel coronavirus. You can find the complete list of our fact-checks on the topic in English here.

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