With the threat of new COVID-19 variants growing by the day, it may seem like a good idea to just double up on masks as you’re heading out the door.
After all, more masks on your face equals more protection, right?
Canadian infectious disease experts say we’re not so sure about that just yet.
“It’s too early to make this decision recommendation and policy recommendation based on a single study,” said Jianhong Wu, Canada research chair in infectious disease modelling at York University.
“I think we need more studies and more data to reinforce the fact that we need better masking … and better education for the general public about the best way of wearing personal protection.”
That single study was conducted by the Centers for Disease Control and Prevention (CDC) in January and released the following month.
The study found that — when a dummy was fitted with a three-ply cotton mask over a medical procedure mask — the second mask formed a tight seal around the face, reducing droplets from a simulated cough by 96.4 per cent for both source and receiver.
However, the study also found that dummies wearing only one medical procedure mask — which was knotted and tucked from the sides to eliminate gaps — also reduced droplet exposure significantly – by 95.9 per cent.
The point of the study was to look at how better-fitting masks could be a powerful weapon in reducing the spread of COVID-19.
But infectious disease physician and epidemiologist Dr. John Conly says some individuals, including journalists, may have misinterpreted the study’s results.
“That’s unfortunate that people cherry-pick the double masking and just moved on to it,” said Conly, who is a professor at the University of Calgary. “This needs to be taken in context, and not the glaring headlines that we’re seeing ‘double masking for everyone.'”
Conly and Wu say because the study was focusing only on the fit of the masks, it leaves a lot of unanswered questions about breathability, efficient filtration and possible harms of double masking.
“We’ve already had reports of individuals wearing tight-fitting masks with eczema of the face, people getting eye irritations and conjunctivitis … and a number of health-care workers have now been complaining about mask acne.” said Conly.
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Conly also points out that the study used dummies that merely simulated a cough, which can turn out very different than a real human cough. The CDC even said that the results of its study should not be “interpreted as being representative of the effectiveness of these masks when worn in real-world settings.” In order to draw better conclusions and gather more data, Conly says the study would need to be duplicated in humans, and in multiple real-life settings.
Wu and Conly also say we need a cluster of evidence and experiments with multiple scenarios that have been peer-reviewed and validated to recommend anything.
Until then, both say health-care recommendations should not be made based on a single study.
“That’s not good science in my opinion,” said Conly.
Should we just throw double masking out the window then?
Some experts say we shouldn’t back away from the notion of double masking, at least not yet.
After all, variant spread is showing no signs of slowing down, which means having conversations about how to improve mask fit, and safety recommendations in general, may not be a bad idea.
“The variants are really lighting the fuel, and I think it’s really putting the spotlight on infection prevention and control,” said Natasha Salt, director of infection prevention and control at Sunnybrook Health Sciences Centre. “But I definitely don’t want to lose sight of the fact that it’s a combination of all these community measures that are actually preventing spread.”
“You wouldn’t even need a double mask, or a triple mask, or any other kind of mask, if we were staying home as much as possible, and only going out for essential purposes.”
Still, Wu and Salt say double masking may be useful to individuals who don’t have any underlying breathing problems, and for those who want to improve the fit of masks they already have.
Wu also says he’s started wearing two masks in crowded areas where it’s difficult to physically distance.
But Salt says — should you choose to take up double-masking — you need to weigh the risks and proceed with caution.
Salt also says individuals wearing two masks may feel the need to start touching their face more often to adjust the masks. (Hint: don’t do it. It could bring in more germs to your nose and eyes, promoting infection.)
Meanwhile, for a Canadian mask manufacturer, business is booming … but not necessarily because of the CDC study.
“I think the spike we’re seeing is more attributed to people converting from overseas masks to Canadian-made masks,” said James Bokla, CEO of Viva Healthcare Packaging.
In October 2020, Viva began to retool its operations to produce PPE on Canadian soil. By December, the Ontario government announced $450,000 in funding will be going towards Viva’s operations, to produce 22.5 million masks per month, by the end of March.
Bokla says they’re way past that target.
“By April, we’ll be at an internal manufacturing capacity of about 30-million pieces per month, and I’m happy to say that most of that capacity is sold. I’d say 99 per cent of our product is shipping within Canada.”
Viva has about 40-50 corporate clients, according to Bokla, but most of their supply is being allocated to government stockpile reserves, or to immediate use in health-care settings.
So to double mask? or not to double mask?
Wu, Conly, and Salt all reiterate that the main takeaway of the CDC study is to make sure masks fit properly, not to just add extra layers.
So if your mask is snug around the eyes, nose and chin, and leaves no gaps on the side, double masking may not make a difference, according to the evidence presented so far.
If you do have gaps on the sides of your mask, the CDC says you should consider using a mask brace, or tying the mask at the ear loops and tucking the bunched up material inwards.
However, if you choose to double mask instead of all these other options, it’s important to note that the CDC only conducted the study on cloth masks and medical procedure masks, and no other combo. The CDC does not recommend layering two medical procedure masks. It also does not recommend layering an N95 mask with any other mask.
Salt says individuals who do not work in health care should refrain from purchasing N95 masks altogether, as they are still in tight supply.
Salt also warns that doubling up on masks should not be taken up by health-care workers, whose masks are of higher filtration and quality. Instead, health-care workers should follow the IPAC recommendations presented to them.
Lastly, if you’re on the hunt for a good quality mask, Health Canada recommends having three-layers, or at least a double layer with a pocket to insert a filter. You can make a filter out of a folded paper towel or a rinsed and dried baby wipe.
Conly, Wu, and Salt are reminding the public double masking should never be seen as a substitute for other health and safety recommendations. Continue to physically distance from individuals outside of your household, and maintain adequate hand hygiene.