Nova Scotia Teachers Union says more information needed on school air quality

The Nova Scotia Teachers Union says there needs to be more communication from the provincial government on air quality conditions in classrooms.

Union president Ryan Lutes said while he was pleased the government purchased some HEPA air filters last year for classrooms without mechanical ventilation systems, more information is needed from the province.

"Right now, government is just saying that all systems are working as intended," Lutes said, "but what is that like in school X or classroom Y? I think that's really important for teachers, parents and kids to have that specific data."

This comes as schools in the province are back to regular form after more than two years of COVID-19 restrictions. The province announced late last month it would continue to encourage school staff and students to "embrace healthy habits, including getting vaccinated, staying home if unwell, sanitizing hands and high-touch surfaces, and creating a supportive environment for those who decide to wear a mask."

Premier Tim Houston announced in January the province was looking to upgrade some school ventilation systems. Since the beginning of the pandemic, the province has spent more than $18 million on ventilation, including inspections, upgrades and repairs, said Education Department spokesperson Susan Mader Zinck in an emailed statement.

Province taking a 'layered approach'

"In addition, we installed 1,600 portable HEPA filtration units in classrooms without mechanical ventilation systems," Mader Zinck wrote, adding that ventilation was part of the province's "layered approach" to ensuring the safety of students and staff.

Lutes thinks the government should provide carbon dioxide monitors to classrooms for real-time data on how the ventilation system is working to push fresh air indoors, which reduces the risk of transmitting COVID-19 and other respiratory illnesses.

As well, Lutes said members of the union are also concerned that there are no mandatory isolation rules in place, leaving room for viral spread within the school environment.

University of British Columbia professor Karen Bartlett said proper ventilation is key in diluting the "particulate matter" released during breathing, speaking and sneezing from people, reducing the risk of potential infection.

Opening windows does work as a ventilation system for older schools with no mechanical ventilation, she added, but then there's the problem of getting fresh air in and old air out, which is where a HEPA filter may help.

Setting out to make a school's ventilation system more effective would be an expensive undertaking, she added.

"To really have an efficient system, it's a massive retrofitting and that's why the expense is ginormous," Bartlett said.

HEPA filters may only somewhat alleviate the risk of spreading and contracting COVID-19 in a school or classroom setting, said University of Waterloo professor Chao Tan.

Tan, who teaches at Waterloo's department of mechanical and mechatronics engineering, said that since classrooms aren't airtight, completely ridding it of viral particles that may be in the room would be difficult and expensive.

In a classroom setting, air is constantly flowing from several directions, he added.

"Your filter may work, but there are many, many ways for the virus to get into the room, like the door and the window … and the students carry virus into the room. The filter itself cannot protect all the students," Tan explained.

"Does a HEPA filter work? I would say it helps. It only helps. It cannot solve the problem by itself," he added.

Tan recommends a multi-pronged approach in the classroom, which involves using a filter, filtering fresh air in through windows, increasing the capacity of the ventilation system or using UV light to sanitize surfaces.

Like Tan, Bartlett believes ventilation is only a part of making indoor environments, like schools, safer when it comes to COVID-19 and other respiratory diseases.

Better ventilation only part of solution, says prof

"We're not going to, by ventilation alone, solve the problem. It's going to be a combination of masking, ventilation and sanitation," said Bartlett.

"It really is a balancing act that we want kids to be back in school. We want to be face-to-face, … so we need to look at the bigger picture of how we can do that and ventilation is absolutely an enormous part of that. It's going to be the cost of doing business to provide adequate fresh air."