Quebec data shows CO2 levels higher than acceptable in a third of classrooms measured

CO2 levels too high in some Que. schools Quebec data shows carbon dioxide levels are higher than acceptable in a third of the classrooms measures.

The number of classrooms in Quebec where CO2 levels exceed Health Canada and the Quebec institute of public health's (INSPQ) recommendations appears to be higher than what the education minister said is appropriate.

Data on Quebec's website shows that on the week starting Dec. 19, 33.2 per cent of classrooms monitored had levels of CO2 over 1,000 parts per million (PPM).

That week, Quebec monitored 3,246 schools and 76,122 classrooms, finding that 20,177 (26.5 per cent) had between 1,000 and 1,500 PPM, 3,892 (5.1 per cent) had between 1,500 and 2,000 PPM, and 1,198 (1.6 per cent) had levels exceeding 2,000 PPM.

"You want to get under 1000," said Montreal cardiologist and epidemiologist Dr. Christopher Labos. "So you're circulating the air so that CO2 levels don't build up, so that respiratory virsuses like a cold, like a RSV, like influenza and Covid, don't hang around in the air of the classroom. Because that's how kids are getting sick, right, we generate CO2 and the longer you're in that classroom, the CO2 levels go up."

Since the end of October, a minimum of 20.5 per cent of classrooms have had CO2 levels over 1,000 PPM.

However, Education Minister Bernard Drainville tweeted Saturday that levels are too high in just 1.2 per cent of schools (829), adding that the INSPQ has deemed 1,500 PPM as an adequate number.

"Still too much but it's 98.8 per cent with an adequate rate," he wrote.

However, info on Health Canada and the INSPQ sites say that studies have shown performance decreases when CO2 levels are above 1,000 PPM.

Health Canada says that levels over 984 PPM have been "associated with a lack of concentration."

"Associations between increasing CO2 concentration, starting at 1,000 ppm (or decreased ventilation rate where that was the metric) and decreased performance in school or office settings (e.g., decision-making, task performance, standardized test scores) have also been observed," the government site reads.

The INSPQ gives a similar warning, stating: "The results of many studies also suggest that exposure to CO2 at much lower concentrations (around 1,000 ppm) may cause adverse effects in some individuals (dizziness, fatigue, headaches, etc.)."

Quebec's "Air quality and installation of comfort parameter sensors in all classrooms in Quebec" guide says that between 1,000 and 1,500 PPM, educators should "open the room's windows and doors wider or more often based on the temperature."

"A daily average concentration of CO2 of less than 1,500 ppm can be used as an appropriate comfort parameter. The ideal threshold is an indoor CO2 level that is no more than 700 ppm higher than the CO2 concentration in outdoor air. For new buildings, the average daily CO2 level must be no greater than 1,000 ppm," it reads.

Drainville said that the government spent $400 million to install 90,000 air monitoring units, and Quebec will spend $225 million in 2023 to improve conditions in schools.

Speaking to CTV News on Sunday, Quebec Liberal Party MNA Marwah Rizqy questioned these figures. She said $400 million went to a variety of renovation expenses, not just air monitoring units.

"No one knows, in Quebec, where the money went for ventilation," she said.

Rizqy, who is the opposition critic for education, said her party tabled a bill to reduce to the CO2 benchmark to 800 ppm.

The minister of education sent out letters on the subject in December, said Heidi Yetman with the Quebec Provincial Association of Teachers.

"Basically giving some guidelines to the school boards on how to deal with high levels of CO2 in classrooms. And again this year it was 'open windows.' Fifty per cent of the schools in Quebec are 'naturally ventilated," that means no mechanical and the only way to get air circulating in a room is with windows opened and classroom doors open," she said.

Yetman also wonders about teachers who spend their career in poorly ventilated classrooms.

"If the ministry of education in Quebec City, if their buildings were not ventilated, and had a failing grade, if they would be living in those buildings," she said, "I'm sure they would've moved out by now."

- With files from CTV News Montreal's Christine Long