'We can reduce exposure': Experts call for ventilation system upgrades to limit COVID-19 spread

As the fourth wave of COVID-19 continues to surge in Alberta, some experts are suggesting taking a closer look at ventilation systems in schools and businesses to help prevent transmission.

Conor Ruzycki, a PhD candidate and Killiam Scholar, has studied airborne transmission of the coronavirus since the start of the pandemic.

“One thing that’s become very clear over the past several months is that airborne transmission of COVID-19 is a very important problem,” Ruzycki said.

He says evidence shows poor indoor ventilation can help spread the virus.

“If your sharing that space with somebody who has COVID-19, there’s a very high risk of transmission occurring,” Ruzycki added. “We can be inhaling aerosol that other people are emitting and if that person is sick with COVID-19, the aerosol that they’re emitting when they do any number of things like talk or even simply breathing, can produce (droplets).

“If we inhale that aerosol that contains virus, we can ourselves become infected.”

In the past week, the Association of Professional Engineers and Geoscientists of Alberta (APEGA) called on the province to review ventilation systems in commercial buildings and schools.

“Alberta has no expert body for ventilation and filtration,” APEGA tweeted on Thursday. “ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) sets ventilation standards in North America and has recognized that airborne transmission of COVID-19 is significant.

“We can reduce exposure by upgrading building heating, ventilation, and AC systems.”

“For them to come out and directly acknowledge airborne transmission is a very big step forward,” Ruzycki said. “I think that should really be quite a motivating factor for people to be taking this quite seriously.”

The Alberta Teachers’ Association (ATA) renewed calls on the province to provide funding to school districts to aid in upgrading ventilation.

“Alberta’s elementary students are crammed into inadequately ventilated spaces, and the government is shirking its responsibility to offer the bare minimum protection (of masking) for those who cannot be vaccinated and their families,” ATA president Jason Schilling said on Friday.

Improving ventilation systems is one part of the ATA’s nine-point plan to ensure a safe return to in-person learning for the 2021-22 school year.

“Much of Alberta’s school HVAC infrastructure is fairly antiquated, and solutions such as opening windows and holding class outside will not be generally possible, given Alberta’s climate,” the plan says. “Consideration must be given to identifying technologies that facilitate air filtering and exchange that can be implemented in classrooms in short order.”

The ATA suggested using portable air cleaners with high-efficiency particulate air (HEPA) filters as a stop-gap measure.

Ruzycki said on top of re-evaluating ventilation systems, masking indoors helps limit the amount of aerosol spread.

On top of limiting the spread of COVID-19, upgrades to ventilation infrastructure would be a lasting investment that Ruzyki says would improve air quality.

“The issue of aerosols and disease transmission is something that we think happens with a lot of respiratory diseases, so really the benefits are not just short term here.”