Calls grow for HEPA air filters in Canadian classrooms

As the highly transmissible Omicron variant fuels record-high case counts, and schools across Canada delay in-person learning, calls are growing for another layer of protection to be added to classrooms — HEPA filters. 

Air purifiers with high efficiency particulate air (HEPA) filters can reduce the concentration of some viruses in the air by capturing small particles, such as the water droplets that can carry the coronavirus.

Jill Davies-Shaw's daughter is in Grade Six at Glenora School in Edmonton. 

In the fall, she and other parents fundraised to buy a portable purifier with a HEPA filter for the classroom. 

Davies-Shaw says, with more acknowledgement that the coronavirus is airborne, there was concern about sending her daughter to in-person learning every day.

"Worrying about virus building up throughout the day and certainly in a classroom, especially in a space where children are removing masks to eat lunch, where they're spending a long time throughout the day — that was something that just made sense," she said.

But parents were told by the school board that ventilation was adequate. The unit was returned.

Now, the Edmonton Public School Board tells CBC News that it is looking into the possibility of installing HEPA filters.

"I think that the time for this is yesterday and it really needs to happen urgently at this point," Davies-Shaw said.

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"I think at this point with how easily Omicron is spreading and how important it is for children to be able to be in-person in the classroom, learning with their peers, that we have to use all of the measures that we have available to us." 

The Public Health Agency of Canada says the effectiveness of HEPA filters against the transmission of the SARS-CoV-2 virus has not been demonstrated yet. It says the filters can be used as an additional tool but should not replace other public health measures.

Despite that, some provincial governments are moving forward.

Ontario has sent thousands to certain schools and will be buying more before students return after the winter break, B.C. has promised them and New Brunswick is looking into the matter.