Editor’s Note: A previous version of this story incorrectly identified a list of 24 schools as being those across the province with elevated carbon dioxide levels. In fact, they were the 24 Anglophone West District schools that don’t have mechanical ventilation systems.

Some of the New Brunswick schools that lack adequate ventilation systems have tested high for carbon dioxide, CBC News has learned, less than a week before students and teachers resume in-person classes.

Of the 60 schools with no integrated mechanical ventilation systems, air quality results for 24 of them found that “certain rooms, although safe, did have carbon dioxide (CO2) levels above 1,500 parts per million (ppm), which are less than optimal for learning,” said Department of Education spokesperson Danielle Elliott.

She did not say how high the readings were, but did say it is not until levels reach 5,000 ppm over an eight-hour period weighted average, or 30,000 ppm over a 15-minute weighted average, that there are risks to occupants’ health and safety.

Asked what the CO2 levels in schools are supposed to be, Elliott replied, “Optimal working or learning environments call for levels of CO2 to be below 1,500.”

Health Canada recommends an exposure limit of 1,000 ppm.

“Studies in humans in school or office settings have found associations between CO2 exposure and mucous membrane or respiratory symptoms, rhinitis, neurophysiological symptoms, a lack of concentration, headaches, dizziness, heavy-headedness, tiredness, and decreased performance on tests or tasks,” the agency states.

Children are among the most vulnerable to the health effects of the odourless, colourless, non-flammable gas commonly created indoors by the respiration of a room’s occupants, it says.

Because of their size, children inhale more air in relation to their body weight than adults. Children may also be more susceptible than adults to the health effects of air contaminants due to differences in their ability to metabolize, detoxify, and excrete contaminants, and because they undergo rapid growth and development.

In accordance with WorkSafeNB guidelines, the cause of any readings above 1,500 ppm warrant investigation, said Elliott.

The school districts that oversee the schools in question are now taking measures to reduce the CO2 levels on a case-by-case basis to best respond to the specific configuration of spaces within the schools, according to Elliott.

Earlier this week, the department said air quality tests conducted at the 60 schools over the past several months have been “within the safe range and did not demonstrate reason for health concerns.”

The testing was carried out through late winter and early spring when students were in the classrooms, Elliott confirmed late Thursday.

“It’s worth noting, samples results followed peak periods of stagnation within the classroom during the day and do not necessarily represent an entire school, but smaller areas such as a gym or classroom.”

List of schools not released by department

Elliott declined to make the list of schools with elevated CO2 levels or the list of schools with inadequate ventilation systems available to the public, directing inquiries to the seven individual districts.

“As school districts are responsible for managing their facilities, they would have the most up-to-date information, including the lists,” she said in an emailed statement.

On Thursday, during a Facebook live question-and-answer session about the back-to-school plan, CBC asked Education Minister Dominic Cardy why the department isn’t releasing the lists, and whether parents have a right to know.

“This gets into sort of a weird area of education governance that we have,” Cardy said.

The school districts — four anglophone and three francophone — are responsible for infrastructure.

“So there’s issues of sort of turf over whose documents these are,” Cardy said.

Public schools are public buildings, and the public should have every right to know what’s going on inside them.– Dominic Cardy, education minister

“But I can tell you that my intention is to work with the districts to release all that information as soon as possible, because I don’t see any reason, COVID or not, the people shouldn’t have access to that. Public schools are public buildings, and the public should have every right to know what’s going on inside them.

“And if that results in more pressure to upgrade schools, that’s fine. That’s what democracy is supposed to be about.”

Only 5 districts respond

Only five of the districts responded to a request for information.

The Anglophone West School District said one of its 24 schools without a mechanical ventilation system had elevated carbon dioxide levels. Burton Elementary had an average reading “slightly above” 1,500 ppm, said spokesperson Jennifer Read. She did not say what the highest reading was.

“It is important to note that CO2 measurements above 1,500 ppm do not constitute a reason for health/safety concerns,” Read said in an emailed statement. “At 1,500 ppm, occupant comfort could be compromised for some individuals.”

The air quality testing was conducted by an independent firm in the spring of 2021. Students were in classes at the time, said Read.

In addition to the air quality testing, school administrators completed a survey to identify concerns at the school level, she said. No information about the survey or the results were provided.

“District facilities management staff conducted meetings with each school administrator to review the survey results, testing results and scope out a plan to address issues identified at each school site. The facilities team is implementing these plans in co-operation with the department,” Read said, without elaborating.

Students and teachers are scheduled to head back to school on Sept. 7. (Sofia Rodriguez/CBC)

In the Anglophone South School District, three of the 23 schools without a mechanical ventilation system had average CO2 readings above 1,500 ppm at some point during the testing, including Back Bay Elementary School, Centennial School and Norton Elementary School, said superintendent Zoë Watson.

She did not say what the highest readings were.

“The tests indicated that our schools are safe for students and staff,” she said in an emailed statement.

Watson said the tests were conducted in March, when the classrooms were occupied.

Between one and six rooms are tested in each school and are chosen based on “which are most likely to have issues if there were any,” she said, without elaborating.

The selected rooms are tested a number of times, and the results are “at times lower than 1,500 ppm and at times higher.”

“Conditions that can contribute to elevated CO2 levels are number of people in the room compared to the size of the room and local environmental issues such as weather, nearby traffic, or industrial activity in the area,” Watson said.

Of the Anglophone North School District’s 29 schools, three are without integrated mechanical ventilation systems, and one has a partial integrated mechanical ventilation system, spokesperson Meredith Caissie said late Friday afternoon.

Testing was conducted in spring 2021 and of those four schools without integrated mechanical ventilation systems, two schools each had a room that recorded readings above the 1,500 parts per million (ppm), Caissie said.

She did not disclose the names of the schools or say what the readings were.

“All test results were found to be within the safe range and did not demonstrate reason for health and safety concerns,” she said in an emailed statement.

The francophone north-east district said only one of its schools, Académie Assomption, has no mechanical ventilation system, but its carbon dioxide readings were normal.

The francophone north-west district said all 18 of its schools have integrated ventilation systems and normal CO2 readings.

Mitigation options limited by COVID concerns

C02 mitigation is often “as simple as ensuring there are more opportunities for air flow,” such as installing fans, the department spokesperson said.

The 2021-22 Healthy and Safe Schools plan prevents this, however, due to concerns about spreading air particles during the COVID-19 pandemic.

The schools can open windows to circulate air. She did not say whether all classrooms at the 60 schools without ventilation systems, or at the 24 that tested high for CO2, have operable windows.

At Anglophone South, three schools without ventilation systems do not have operable windows, said Watson — Bayside Middle School, Saint Rose School and Westfield School. But the three with elevated CO2 readings do.

“In order to optimize air quality, schools have been encouraged to open the windows and classroom door at times during the day, moving students more freely throughout the school day, and in non-COVID times, operating fans,” she said.

Some parents have raised concerns about opening windows in the dead of winter. Asked how those concerns will be addressed, Watson said the windows do not need to be open for long periods of time, and can be opened when students are in other parts of the school, such as the cafeteria or gym, or before school starts and during recess.

At Anglophone West, all 24 schools without ventilation systems have operable windows, including the one with elevated CO2 readings, said.

Schools have been instructed that they can open the windows on cold days when students are not present to circulate the air, and then close them to allow rooms to warm to a comfortable temperature, she added.

The two Anglophone North schools that had rooms with elevated CO2 readings “have multiple windows that are opened to promote air flow, and occupants are only in those particular rooms for a limited amount of time each day,” Caissie said.

Followup tests ‘at some point’

The department will closely monitor the measures the districts take through the coming months to ensure the schools are “not only healthy and safe, but optimal for learning and working,” Elliott said.

Asked whether the province will conduct followup air quality testing, she did not initially respond.

But the Anglophone West spokesperson and Anglophone South superintendent both said more testing will be done “at some point in the future,” under the direction of the department.

Elliott later confirmed air quality conditions will continue to be monitored and tested this school year and “districts and the department will take appropriate action where required to ensure any risks to health and safety are mitigated.”

Other jurisdictions

Quebec is installing CO2 detectors in classrooms in a bid to track the quality of the air students are breathing and help limit the spread of COVID-19.

Elevated CO2 levels can help to identify locations where there may be poor ventilation.

Ensuring appropriate ventilation and filtration are the most effective measures to reduce the airborne transmission risk, according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). This organization provides guidance and sets standards that many institutions, such as schools, follow to ensure safe ventilation systems.

In Ontario, the province recently announced it would invest an additional $25 million to buy thousands of high-efficiency particulate air, or HEPA, filters for schools before the first day. 

All classrooms, gyms, libraries and other spaces without mechanical ventilation will be required to have standalone filter units, including kindergarten classrooms.

The extra funding brings to $600 million the amount the provincial government alone has dedicated to improving school heating, ventilation, and air conditioning, or HVAC, systems.

Ventilation a ‘big priority’ after COVID

Cardy acknowledged “the higher quality central ventilation system you can have, the better” to help prevent the transmission of COVID.

“The concern is, of course, right now we can’t close down schools … to do a full rebuild, to put a ventilation system in,” he said, referring to the school year about to begin. He did not explain why no rebuilds were completed during the summer break.

“In general, the recommendation was, don’t do little Band-Aid measures, because those can sometimes make things worse,” Cardy said, citing in-class HEPA filters as an example.

“As much as they can absorb some COVID-19 into them, when they’re circulating the air in the room, they can be moving in COVID air around and actually infecting more people.

“And the last thing we want to do is, in an effort to try and make things better, end up by causing people to get sick. 

“But coming out of COVID, ventilation in schools is a big priority on the infrastructure side for the department.”

Education Minister Dominic Cardy said the schools all have safe levels of oxygen and the air is safe. It’s an issue the department takes seriously after having problems in the past with asbestos and radon, he said. (CBC/Facebook)

Installation of ventilation systems at some of the 60 New Brunswick schools is expected to begin in 2022, the department has said.

Officials are working with the Department of Transportation and Infrastructure to develop the project requirements and budget for each school, based on a prioritized list. 

“Due to the extensive work required, this will be a multi-year program,” spokesperson Flavio Nienow said.

The department undertook the review earlier this year, based on the recommendation of a working group comprised of representatives from Public Health, WorkSafeNB, the Department of Transportation and Infrastructure and the Department of Education.