Some health experts urge institutions and institutions to reconsider the use of plexiglass as a measure against COVID-19, arguing that barriers may even be “counterproductive” when they obstruct the ventilation needed to avoid spreading the more transferable delta variant.
Since the start of the pandemic, plastic barriers have become a common sight in places like shops and schools.
But just as coronavirus has evolved since then, experts say our understanding of the effectiveness of these barriers must also evolve – especially as colder weather and relaxed pandemic rules mean more people are indoors.
Dr. Peter Juni, an epidemiologist at St. Michael’s Hospital in Toronto and a member of the Ontario COVID-19 Science Advisory Table, wants people to “throw the plexiglass out” in most situations.
“The challenge with plexiglass walls, if they are not implemented very selectively, is that they can actually inhibit ventilation if the air can not circulate well,” June told CBC News.
“If you start fragmenting the space unnecessarily with plexiglass walls, it’s actually counterproductive because the air can’t circulate properly,” he said.
“And there is even some observational evidence to suggest that this could actually make things worse instead of better.”
Dr. Raj Bhardwaj, a physician and clinical associate professor at the University of Calgary, previously told CBC Radio’s Information Tomorrow Moncton that the delta variant has “evolved to be able to be transferred more efficiently through the air”, which makes ventilation crucial when it comes to limiting the risk.
SE | Experts reconsider the use of plexiglass to prevent the spread of COVID-19:
“These plastic barriers … can disrupt the normal ventilation of a room, they can create dead zones where the air becomes stagnant and the airborne viral particles can build up over time,” he said.
“They may be able to help avoid a direct hit from someone talking to you wetly or sneezing at you if they are not wearing a mask … but if you are not in a well-ventilated room either, these plexiglass barriers can just funnel aerosols into another part of the room. “
‘Important in certain situations’
BC Provincial Health Officer Dr. Bonnie Henry says, however, that barriers make a difference for those who interact closely with the public at high volumes.
“Barriers are important in certain situations, and I think of fast food restaurants and coffee shops when that barrier protects you from the person on the other side of it,” she said at a news conference Tuesday.
“In and of themselves, they are not everything, but they definitely make a difference.”
Jeff Siegel, a professor of civil and mineral engineering at the University of Toronto who studies indoor air quality, welcomed June’s recommendation to get rid of plexiglass due to airflow problems, but also agrees with Henry that they can be helpful in certain workplaces.
“There are times when you want to keep people separate, and sometimes a physical barrier is the easiest way to do that,” he told CBC News, noting that barriers make more sense in a cramped space like a grocery store than in an office environment. .
“If you want to make a barrier, then do it well,” Siegel said.
“[It] should be big enough … to really stop many of the drops from penetrating. “
Experts say the best defense against COVID-19 indoors is a multi-layered approach that includes good ventilation.
“What you want is basically just good ventilation, reasonable cleaning … enough things to disinfect your hands and good masks,” June said.
“It’s definitely much more important [than plexiglass]. “
Companies that have invested thousands of dollars in barriers may feel frustrated by calls to drop them, which Siegel says is “a very reasonable response” due to previous COVID-19 announcements.
“I understand why people are sad, but the reality is that the evidence is changing,” he said.
“While we had good reason to believe that plexiglass could have made a difference back then, we now know there are more challenges.”