Fresh ideas

Toronto library’s CO2 monitor lending program a big hit

You can borrow a lot of neat things from the Toronto Public Library.

Books, obviously. Not just books, though. You can also borrow museum passes, videos, Arduino kits (they measure the intensity of light), musical instruments and, as of this year, even CO2 monitors.

This summer, Prescientx, a Canadian engineering and manufacturing company, donated 50 Aranet4 carbon dioxide monitors to the library. And, so far, they’re a hit with patrons, who are embracing the technology and measuring the air quality everywhere they go.

“The response has been really enthusiastic,” said Ab. Velasco, manager of innovation, learning and service planning at the library. “They’re very well circulated and, if you’re on social media, not a day passes without people talking about it.”

And mostly, what they’re talking about are the readings they’re seeing in public spaces.

“People can crowdsource readings of different public spaces, so you kind of have this mapping project of different public spaces and the indoor air quality,” explained Velasco. “It’s been really interesting to see this kind of activation in the community.”

In response, there’s even a new clean air app, Raven, which had over 3,000 followers when last we checked. The day we looked, a lot of people were posting about the air quality at York University. Unsurprisingly, lecture halls and the bookstore, which are busy and full of people, had the worst readings.

In case you aren’t familiar with these monitors, the reason they’re trending has everything to do with COVID-19. Long before the Toronto Public Library started lending them out, people had been using them as a risk assessment tool. The idea is that they can measure how much exhaled air from other people you’re taking in and, by extension, the level of risk you’re facing in a certain space.

I’ve seen several posts on social media from people taking readings in public spaces. When the numbers start to climb they interpret it as an alarm warning them to get out.

To what degree can a CO2 monitor predict your risk, though? We asked Jeffrey Siegel, a professor of civil engineering at the University of Toronto.

“I think it’s great that libraries are making the monitors available and I’m glad people are interested in ventilation,” said Siegel, who’s been stressing the importance of ventilation as a public health measure for much of his career.

“But trying to determine your infection risk with a CO2 monitor is actually much more complicated.

“I completely agree that the overall number can be kind of useful to say there’s a high or a low level of ventilation in a space,” Siegel said. “But there are a lot of other factors, like the air flow pattern in the room and your proximity to an infected person.”

Different people also breathe out different levels of carbon dioxide and the amount of carbon we exhale depends on our activity level.

“I think we have to be very careful. Like there’s no way I feel at all comfortable telling you there’s this magic threshold below which you’re safe and above which you’re not safe.”

Siegel, who emphasizes that he loves CO2 monitors and uses them all the time in his research, says the most effective way to use them is measuring levels in the same space over time — as opposed to taking a single reading on your tour through campus. If CO2 levels suddenly jump in a space, for example, that could alert people to a malfunctioning system.

“I really like that the library is making them available,” he added. “As a general way of understanding your indoor environment, I think it’s actually kind of cool and can help people start to learn things that I think are very useful to learn. I like people exploring their indoor environments.

“But I get a little bit nervous when we start making definitive decisions about things like infection risk.”

So, if you’re planning to borrow one, it might make more sense to use it as an educational tool than a COVID alert device. And education is, after all, a big part of the Toronto Public Library’s mission statement.

“At the library we’ve always provided people with access to information, so this is a unique way to continue this tradition,” said Velasco, adding that the library’s Digital Innovation Hubs provide Torontonians with computers, wireless network access, computer training and even recording equipment.

“So this is just another way we help bridge the digital divide,” he said.