Sept. 14, 2020
With Ontario and Alberta requiring non-medical masks for students in Grade 4 and above when they return to school this fall, parents may be wondering which kinds are safest and most comfortable for children to wear during the school day.
Although there is no shortage of options, ranging from the homemade variety to brand-name masks, some are better than others.
We asked experts for their advice:
MEDICAL VERSUS NON-MEDICAL MASKS
Some children may find lightweight, disposable surgical masks more breathable than other types of masks. But neither they nor N95 respirator masks are ideal for wearing all day, said Anna Banerji, a pediatric infectious-disease expert and associate professor at the University of Toronto’s faculty of medicine.
Both are meant for single-use and to be worn for relatively short periods of time, Dr. Banerji said, explaining they tend to get wet with droplets from breathing after a while and can lose their shape.
If they become misshapen, N95 respirators, which filter at least 95 per cent of particles, may not work, since they require an airtight seal around the nose and mouth. (Although N95 respirators designed for children can be found online, Dr. Banerji said she did not think children would tolerate keeping them on all day.) Surgical masks, meanwhile, can rip when they get wet, she adds.
There are other reasons not to use surgical masks and N95 respirators. These should be reserved for health care workers and those working in nursing homes and funeral homes, said Catherine Clase, an associate professor of medicine at McMaster University and nephrologist at St. Joseph’s Healthcare Hamilton who has been researching the efficiency of cloth masks.
“We absolutely must not divert the supplies of those masks to other purposes right now,” she said.
Plus, there’s the environmental impact to consider.
“If every adult Canadian needs to use a mask three times a week in the next year, we would need three billion masks,” said Dr. Clase, a member of the Centre of Excellence in Protective Equipment and Materials at McMaster in Hamilton. “That’s a lot of disposables.”
STYLE AND FIT
Make sure the size is right. The mask must cover the child’s nose and mouth, Dr. Banerji said, adding it should also be age-appropriate.
“So if kids can’t tie things around their head, then elastics may be better,” she said, noting children may not always have someone to help them with their masks at school.
According to the Public Health Agency of Canada, non-medical masks or face coverings should not be worn by children under 2.
If the mask has elastic ear loops, they should not chafe or cause irritation, Dr. Banerji said.
She recommended choosing masks that children can take ownership of. Especially for younger children, that could mean helping them select one in their favourite colour or with prints of their favourite cartoon characters. This may help encourage children to wear them, she said.
Dr. Clase said researchers do not yet know what shape of mask is best. She and her colleagues at McMaster created a website, Clothmasks.ca, to provide evidence-informed guidance on cloth masks. On the site, they offer instructions on how to make pleated masks, based on the common design used for surgical masks.
“We know the pleated design is successful in hospitals; it fits a lot of people,” Dr. Clase said. “But that’s not to say that it’s necessarily better than a cup-shaped design or a more molded design because we just don’t have those comparable experiments.”
The Public Health Agency of Canada says masks with exhalation valves are not recommended because they allow infectious respiratory droplets to spread outside the mask and do not protect others.
COMPARING CLOTH MATERIALS
In a peer-reviewed article, published in July in the journal Mayo Clinic Proceedings, Dr. Clase and her team examined the research literature on the filtration properties of masks made of different cloth materials, thread counts and weaves.
They suggested the best evidence points to the use of plain-weave cotton, at least 100 threads per inch, in three to four layers, Dr. Clase said. She explained this advice is based on the historical use of masks made of muslin, which is a plain-weave cotton fabric, as well as experiments with plain-weave cotton tea towels.
On Clothmasks.ca, the researchers also recommend other materials: cotton or poly-cotton blend flannel, at a minimum of 90 threads per inch, tea towel material, or heavy, good-quality cotton T-shirt fabric. While the masks should have at least two layers, three or four layers is better, they said.
They noted there is a trade-off when more layers are added. Extra layers may increase the filtration efficiency but make it less breathable and, thus, less comfortable to wear.
Dr. Clase explained, however, that most kinds of cloth probably offer some filtration. It is important to choose something your child will use and feel comfortable wearing, she said.
“A mask that you wear is better than a mask that you don’t,” she said.
She suggested keeping at least three masks for each child. That way, while one is in the wash, they can wear one and have another to spare. She also recommended sending them to school with hand sanitizer, which they should use whenever they touch, remove or put on their mask, and a brown paper bag, in which they can stow their mask – outer surfaces folded together – when they eat lunch.
There is some research to suggest face shields can help protect individuals against COVID-19, Derek Chu, a clinician scientist at McMaster, said in an interview in June, after the publication of a systematic review and meta-analysis he co-authored on the use of physical distancing, masks and eye protection for preventing the transmission of the coronavirus. But he noted there has been no research offering a head-to-head comparison between masks and face shields.
Dr. Clase said she was not certain face shields could be used as a substitute for a mask.
“I wouldn’t want to suggest that people use it instead of masks regularly,” she said. “But if there are people who absolutely can’t tolerate a mask – people who have contraindications to masks whether it’s psychological or a respiratory problem – then face shields definitely have a place.”
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