Nearly 83% of tested N.B. schools exceeded peak CO2 limits, air quality results show

More than two weeks into the school year, New Brunswick has released the school air quality test results from 2022-23.

Twenty-nine of the 35 public schools tested last winter had peak carbon dioxide levels above the Department of Education's threshold of 1,500 parts per million (ppm), shown in results posted online and included at the end of this story.

Two of the schools had levels more than double that, including Anglophone West School District's George Street Middle School in Fredericton, which had the highest peak reading in the province at 3,418 ppm, as well as the highest average reading, at 1,709 ppm.

Carbon dioxide, or CO2, is an odourless, colourless, non-flammable gas commonly created indoors when people exhale.

It's used as a proxy to measure air quality and the rate at which air is being renewed, which can also serve as a warning sign about the risk of spread of COVID-19 and other respiratory illnesses, according to experts.

Peak limit 'very poor,' says air quality expert

The Department of Education has set 1,500 as the "peak desirable CO2 reading" for schools, in consultation with WorkSafeNB and the Department of Transportation and Infrastructure.

But an Ontario expert on indoor air quality describes that level as "very poor."

It would "be indicative of really the range where you would expect what's called 'sick building syndrome,'" said Joey Fox, a heating, ventilation and air conditioning engineer and chair of the Ontario Society of Professional Engineers' air quality advisory group.

"A lot of people are complaining about it … it smells really bad, you're going to have higher levels of different volatile organic compounds, which are also just bad for your health," he said.

"And of course, the risk of disease transmission is much, much higher."

Fox said the school averages are a more important measurement than the peaks because "it's impossible to really get a full story just from one number."

The averages should be no higher than 1,000 ppm, he said.

"That's not great, but that is kind of what's acceptable for indoor air quality," said Fox, citing the American Society of Heating, Refrigerating and Air-Conditioning Engineers' (ASHRAE) standard for ventilation, which, he stressed, is based only on creating a healthy, comfortable environment — not on protecting people from infectious diseases or from particulate matter, such as wildfire smoke.

Around 800 ppm is better, he said.

Of the 35 schools without integrated mechanical ventilation systems tested, 19 had averages over 1,000 ppm, and 27 were above 800 ppm.

No response from department

The Department of Education did not respond to a request for an interview, comments or more information about the latest results.

But its website says, "All test results were found to be within the safe range of CO2 levels (below 5,000 parts per million over an eight-hour period weighted average, or 30,000 ppm over a 15-minute weighted average) and did not pose a risk to occupants' health and safety."

Fox said it's not really about the safety of the CO2 levels themselves — CO2 is a tool to gauge overall air quality.

Asked whether parents, teachers and other staff were advised of the air quality results, Anglophone West, Anglophone South and Anglophone North all said the results were within WorkSafeNB guidance and "did not pose a risk to … health and safety."

The Anglophone East and Francophone South school districts did not respond to a request for comment. 

Based on 1 day of testing in 10% of classrooms

The air quality results are all based on a single day of testing in about 10 per cent of classrooms per school over an eight-hour period of a regular school day, the department has previously said.

Only schools without mechanical ventilation systems, which had peak CO2 levels above 1,500 ppm the previous year, were tested.

New Brunswick has about 17 other schools without proper ventilation systems, and another roughly 234 schools that do have ventilation systems.

Research and Productivity Council (RPC) and Alltech, which conducted the testing, determined the methodology, in co-operation with the Department of Transportation and Infrastructure, according to the department.

"The department is relying on the expertise and advice of the experts hired to do the work," a spokesperson has previously said.

Fox believes the methodology used could artificially reduce the actual CO2 levels since students are not typically in the classrooms the whole day, such as during lunch and recess.

Other factors could also lower the results, he said, such as the tested classrooms having fewer people in them, windows being open or "leaky," or it being a windy day when more air can leak into the building.

Depending on testing conditions, even schools that had averages below 1,000 ppm might still be too high, said Fox.

Planned upgrades behind schedule

"The government is committed to ensuring all school environments in the province are healthy, safe, and optimal for learning and working," Department of Education spokesperson Charles Renshaw told CBC last month.

The department is following a multi-year program to ensure all schools are equipped with mechanical ventilation systems.

Eleven schools were slated to receive a new system this year, Education Minister Bill Hogan told the legislature in April.

Eleven projects have "entered the construction/installation phase," said Renshaw, but six are now scheduled to be completed in 2024.

"Despite continued labour and supply issues, work is progressing as quickly as possible, and is currently scheduled to be complete by the end of 2026," he said.

Anglophone West School District continues to take measures to "reduce CO2 levels on a case-by-case basis that best responds to the specific configuration of spaces within a school," said spokesperson Jennifer Read.

For example, in addition to HEPA filters, windows and doors are opened to "allow out movement of air," and exhaust fans are checked to ensure they're "pulling air through the buildings," she said.

The district also continues to follow guidance from both the Department of Health and the Department of Education on reducing the spread of respiratory viruses, said Read.

Anglophone South School District is also following guidance from both departments and has invested in industrial dehumidifiers for every school, said spokesperson Jessica Hanlon.

"Often, air quality can be improved by simple measures such as ensuring there are more opportunities for air exchange, such as opening doors and windows for a period of time or having students move throughout the school through the day, as they would for recess, or moving between classes," she said.

The vast majority of schools in the Anglophone North School District  "already have integrated mechanical ventilation systems that are regularly maintained and operated in accordance with applicable codes and regulations," said spokesperson Meredith Caissie, adding that schools lacking those systems are equipped with portable HEPA filtration units installed as per department guidelines.

New standard to control infectious aerosols urged

Fox said one of the most important ways to prevent illness, and protect both vulnerable people and the health-care system is to adopt a new ASHRAE standard aimed at reducing the risk of disease transmission through exposure to infectious aerosols.

Instead of focusing on indoor-outdoor air exchanges per hour, it sets "equivalent clean airflow" requirements for different types of settings which can be met by providing outdoor air to dilute infectious aerosols, filtering of indoor air to remove them, or disinfection technologies such as germicidal ultraviolet light.

"Obviously schools, this is where we're sending our kids, they're there all day long and they have no choice," he said. "Providing them with a healthy environment is a no-brainer and I think every parent should be asking for that."

Asked what, if any, changes are planned for New Brunswick schools as a result of the new ASHRAE standard, Renshaw said all new mechanical ventilation systems being installed from this year forward will take the new standard "into consideration."

'Massive economic payback' with clean indoor air

New Brunswick and other provinces should also enact a clean indoor air quality act, which would see all public buildings tested, particularly schools, long-term care homes and health-care facilities, said Fox.

"People should have a right to clean air," he said.

Proper ventilation and filtration of crowded public indoor settings also comes with a "massive economic payback," said Fox. They can significantly reduce the costs of illness, with benefit-cost estimates ranging anywhere from three to 100 times, he said.

Meanwhile, any money saved on indoor air quality is just "pushed on to the health-care system," argued Fox.

"You're just making people sick and we're going to pay for it, but we're paying by treating sick people instead of spending money on keeping people healthy."

In June, New Brunswick passed a motion by the Official Opposition to update the provincial Clean Air Act and improve air quality in public buildings to reduce the spread of airborne illnesses, such as COVID-19.

The government is not obligated to take action on Motion 36, which calls on the government to "bring forward a plan to monitor, report, and improve air quality systems in public buildings like schools, hospitals and government buildings to mitigate the risks associated with the transfer of airborne illnesses, airborne contaminants, and other harmful agents."

Asked what, if any, action has been taken since then, or what, if any, changes are planned, the Department of Education spokesperson Renshaw replied: "While we are exploring potential next phases of the program, providing mechanical ventilation systems to schools that do not have one remains the priority."

In the meantime, schools without proper ventilation continue to use portable air filtration devices with high-efficiency particulate air (HEPA) filters.

Corsi-Rosenthal box designer challenges province

Fox commends the province for its planned school ventilation upgrades, which he understands takes time, and its willingness to test air quality and post the results.

But he has some suggestions for improvements.

One short-term measure he recommends would be the use of Corsi-Rosenthal boxes —  homemade air purifier systems made from four filters taped together to form a cube, with a box fan taped on top.

They're inexpensive and "likely much more effective" than the filters currently being used, he said — "at least twice as good."

New Brunswick schools cannot accept donations of Corsi-Rosenthal boxes or HEPA filters.

"Air purification systems are designed for the specific space and installed by professionals," a department spokesperson has said.

Richard Corsi, the dean of engineering at the University of California who co-created the design, publicly challenged the province's position.

"The case for CR-Boxes as a highly-effective and cost-accessible means for lowering student & teacher inhalation exposure to virus-laden respiratory aerosol particles, wildfire smoke and other harmful particles is overwhelming," he posted on social media, adding that he'd be happy to speak with someone in government about it.

The department didn't say whether it took Corsi up on his offer.

Annual tests, results 'not ideal'

In addition, Fox thinks all schools should be tested — including those with mechanical ventilation systems — to ensure they're operating properly.

They should also be tested more frequently to keep on top of any problems, he said.

Testing once a year and releasing the data a year after the fact is "definitely not ideal."