Ventilation, not class size, is the big issue for school boards, experts say

Ont. teachers' federation concerned about in-person class Harvey Bischof, President of the Ontario Secondary School Teachers' Federation, says there are not clear safety standards for students returning to class.

TORONTO — As we creep closer to the reopening of schools across the country, experts are pointing out that ventilation within schools is an under-discussed issue in a COVID-19 world.

In order to try to ensure the safety of students, teachers and staff, many school boards are minimizing class sizes and staggering when cohorts take lessons in order to keep students within a smaller bubble. Depending on the age of students and the region, the wearing of cloth masks is also either required or recommended.

But these measures alone fail to address the major infrastructure problem that plagues many schools still: ventilation.

Colin Furness, an infection control epidemiologist, told CTV News Channel that there is no magic number for how big class sizes should be, because it depends on the density and airspace within individual classrooms.

“I worry a lot that all of the discussion and focus on class size leaves us ignoring something that is actually more important for safety, and that’s air quality,” he said. “I haven’t heard enough about classroom-by-classroom inspections to see if the air quality and ventilation is adequate. You can shrink a class, you can take kids out of the room, but if you don’t ventilate the room, the ones who remain are still in danger.

“Some classrooms don’t even have windows in Ontario. So that’s an issue."

He added that he’s personally walked by older schools where it’s clear that “windows have been painted shut for years, maybe decades.”

According to Dr. Matthew Oughton, an infectious disease specialist, this issue with the actual buildings themselves is one we’ve seen before, with many long-term care facilities.

“Often, these buildings are older, have inadequate facilities for allowing proper physical distancing, often they have inadequate facilities for proper ventilation,” he told CTV News Channel. “There’s many school buildings where you can’t even open windows, which is a pretty simple way to improve the ventilation, so these are all things that are going to be working against us.”

And school buildings don’t have to be extremely old to be at risk of having poor ventilation.

Mohamed Ouf, a professor in Concordia University’s Department of Building, Civil and Environmental Engineering, told CTV News Montreal that buildings built in the 1980s or even the early 1990s could still not meet the ventilation requirements of today, even without taking COVID-19 into account.

In Quebec alone, more than half of the schools were officially classed as being in “poor condition” when it comes to infrastructure, according to the most recent 10-year government report.

Our understanding of the way COVID-19 spreads is still not perfect. After being urged by more than 200 scientists to add airborne transmission to their list of ways the virus can be spread, the World Health Organization released a scientific brief in July indicating that the scientific community was studying the possibility.

“Short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons cannot be ruled out,” the brief stated.

Droplets produced when an infected person speaks or coughs is the main way that the virus spreads, scientists believe, but the evidence that asymptomatic or pre-symptomatic spread also occurs has led scientists to consider airborne transmission more closely. This is when virus-carrying microdroplets stay suspended in the air for a longer period of time after heavier droplets have fallen to the ground.

How big a role airborne transmission might play in the spread of COVID-19 is still not clear, but if it is a threat, ventilation and air flow within an indoor space is crucial to look at.

Furness said to be on the safe side, school boards should think about implementing short-term ventilation solutions if they have inadequate ventilation.

“We need portable air scrubbers in classrooms right away,” he said. “Because that can be done quickly and easily. Is it ideal? No. But one air scrubber in a classroom might actually have a much bigger impact than taking three or four kids out.”

He added that as children return to school, their families should take the extra step of limiting their own social interactions in order to keep their bubble as small as possible now their child will be interacting with more people in their class.

“We need those smaller bubbles,” he said.

Although he believes schools need to be doing more on the ventilation angle, he says that for the time being, his children will be heading back to school in September.

“I’m doing that comfortably because I believe that is safe now,” he said. “That could change, but for now, I think that is a safe, good thing to do, especially for kids’ development and mental health.”

With files from CTV News Montreal’s Andrew Brennan and Selena Ross