After more than two years of the pandemic, ventilation and air quality in Quebec schools continue to be a problem. According to an analysis of data obtained by The duty Under the Access to Information Act, nearly half of public primary and secondary school buildings in Quebec are not mechanically ventilated.
As a result, 45% of establishments must use “natural” ventilation, i.e. opening windows, since they do not have a mechanical system, according to data by construction phases from the Ministry of Education. . Adding buildings where the ventilation system is only partial—when one part of the building is mechanically ventilated and the other not—there are 61% of primary and secondary schools that are therefore not entirely served by a mechanical ventilation.
However, ventilating a school mechanically is the best way to better control the parameters of air exchange, according to experts consulted by The duty. This is also the reason why new schools are built with a mechanical ventilation system, says building mechanical engineer and member of the COVID-STOP collective Manuelle Croft.
“It’s much simpler because you can use control systems to manage ventilation so that it is activated during occupancy and can adapt to the needs of users”, summarizes she.
Conversely, it is difficult to ensure a constant supply of fresh air by relying only on the opening of the windows, in particular because of the winds which change direction and speed at length year, argues Stéphane Bilodeau, engineer and air quality specialist, also a member of the COVID-STOP collective.
“A few days a year, natural ventilation may be adequate, but the vast majority of the year, it will not be sufficient in terms of the fresh air supply. maybe [le vent] will not even be in the right direction, i.e. we will rather circulate air from the inside to other classes rather than air from the outside [vers l’intérieur] “, he says.
For its part, the Ministry of Education affirms that “the buildings constructed [dans les années 1960 et 1970] were designed to promote natural ventilation through the orientation of the building, the use of skylights, the design of corridors, etc. “.
However, the disadvantages of natural ventilation even go well beyond air quality, for Manuelle Croft. The one whose children attended a naturally ventilated school during the pandemic says her concerns were not so much about the type of ventilation as about the responsibility of school staff members.
“That is the problem with natural ventilation. The mental load of ventilation rests on the shoulders of people who already have a high mental load. […] When we are in the heat of the action of our teaching, we are not necessarily sensitive to the fact that it has been a long time since we opened the windows”, she underlines.
For his part, the medical specialist in health and environment at the National Institute of Public Health of Quebec (INSPQ) Stéphane Perron believes that the two ventilation systems can be just as effective as the other if they are well maintained and “optimized”.
“Mechanical ventilation has its complexities too. It has to be very well maintained. In theory, we think it can be higher [à la ventilation naturelle]but in practice, it’s not always so clear,” he adds.
The Ministry of Education has specified to the To have to that by calculating the types of ventilation according to the surfaces of the primary and secondary buildings, 67.4% of the surfaces would be mechanically ventilated.
Air quality not guaranteed
A mechanically ventilated school is not necessarily synonymous with good air quality. CO Readers2 provided to teachers during the pandemic have made it possible to measure significant differences in measurements within the same school, denounces the DD Marie-Michelle Bellon, specialist in internal medicine and coordinator of the COVID-STOP collective.
“In schools where there was mechanical ventilation, [le taux de CO2] was completely variable from class to class. In the same school, there were levels of CO2 impeccable in some classes and others where for some reason the numbers were super high. »
This is the case for Cindy (fictitious name), teacher in a secondary school in the Lanaudière region. The one whose identity is protected for fear of reprisals from her employer told the To have to that, despite the mechanical ventilation that serves his establishment, many premises have shown abnormal levels of CO2. Many of these classrooms do not even have a window to ventilate the premises.
“What we were told was to open the door. […] But there’s not much that happens when a door is open,” she says with a touch of irony.
If Cindy regrets that the “poor ventilation” and the heat have harmful effects on the concentration of the students as well as on the level of energy of the teachers, she especially denounces the “lack of coherence” of the management of the file. “Since we are mechanically ventilated, we are considered ‘ok’. We do annual interviews. [du système], but there are no plans to improve it. »
Summer work?
The teacher claims to have received no news concerning work or palliative measures for the next school year. The summer holidays are however the ideal period to carry out construction sites, claim many speakers, like the president of the Autonomous Federation of education, Sylvain Mallette.
“We know that the virus spreads less when it is hot. The infection rates have always decreased during the summer period, but the same questions will arise in the fall when the cold weather will resume and we will have to close the windows, ”he is indignant. Mr. Mallette pleads for a lowering of the “acceptable” concentration threshold of CO2 from 1500 ppm to 1000 ppm, as well as the reintroduction of COVID-19 outbreak monitoring.
The DD Marie-Michelle Bellon, from the COVID-STOP collective, also hopes to see concrete measures in anticipation of the fall. “Summer is the time to act, the students are not there. In addition, if we look at what is happening in Portugal and Great Britain, there is a new wave coming, ”she believes.
For its part, the Ministère de l’Éducation du Québec (MEQ) ensures that To have to that “all of the CSS [centres de services scolaires] and CS [commissions scolaires] have projects, completed or planned, related to indoor air quality in their buildings”.
CSS and CS plan to invest $225 million for ventilation in 2022, says the MEQ.
Even if children are generally less likely to develop serious symptoms of COVID-19, they can still spread the virus to those around them, recalls virologist Benoit Barbeau, professor in the Department of Biological Sciences at UQAM.
“If your ventilation system is not adequate and you are unable to [d’assurer] good changes of air, it is certain that your risks of transmission are accentuated. And this prevention applies to all other respiratory viruses, he underlines.
For engineer Stéphane Bilodeau, it is essential to tackle “the problem of air quality”, and particularly in naturally ventilated classrooms. “Temporarily, it is better to open the windows, because sometimes it will help. It’s better than doing nothing, but it’s not a long-term solution. It’s a plaster on the bobo”, he concludes.