When Katrina McGuire began aspiring to a zero-waste lifestyle two years ago, she found that bringing her own containers to grocery stores was a small but significant step in reducing her reliance on disposable plastic.

Now that the COVID-19 outbreak is causing Canadians to revert back to single-use material in an effort to slow the spread of the virus, McGuire and other zero waste advocates are facing some challenges.

McGuire, a Toronto resident who runs the Danforth Reduces project in the city's east end, says that while a widespread increase in the use of plastic bags could be troubling, there are other ways to maintain environmentally-friendly habits.

"There's concern for sure," McGuire said in a phone interview with The Canadian Press. "But the zero-waste movement isn't just relegated to doing groceries in a zero-waste way. It's all about repairing and repurposing and re-homing second hand.

"So I think those activities can definitely still continue without too much interruption. And I don't think the community is going to stop wanting to participate in those activities."

McGuire doesn't reduce all her trash to a single mason jar like some in the zero-waste movement, but she does aim to limit it whenever possible. She's still opting for reusable bags -- washing them afterwards in the laundry or with soap and water in the sink to ward off possible contamination -- and repurposes plastic and other materials.

With Canadians buying more non-perishable items to limit grocery trips during the pandemic, McGuire said it's more important now to think about ways to repurpose. Using an empty plastic bag from frozen veggies as a liner for a trash can is one example. Better yet is buying fresh and flash freezing at home.

"Zero (waste) is the goal, but it's also pretty unrealistic," McGuire said. "Most of us are just trying to reduce waste in ways that average people are not doing at this current moment.

"And every time you learn a new tip or new way to reuse, it's like you've unlocked an achievement. That's the fulfilling part of it."

Paul Mensink, an assistant professor of environmental studies at Western University in London, Ont., also sees the rise of single-use plastics as a potential problem.

He worries it could have an impact beyond the pandemic, with peoples' suspicions of reusable items lingering for months amid safety concerns.

"As a society we were really making a lot of progress on (reusable) bags and that sort of thing," Mensink said. "This is going to last for a pretty long time and even afterwards, getting people to switch back, that's going to be tough."

Mensink sees another issue with bulk shopping though -- Canadians buying too much food and throwing out more than they normally would.

That food waste, he says, is "one of the biggest problems in terms of emissions."

"If we take that waste and throw it into the garbage can, then that goes to the landfill and produces methane, which is way more potent than CO2," Mensink said, adding that organics should be composted whenever possible.

While the use of plastics may increase over the course of the coronavirus outbreak, Mensink said one of the bigger environmental issues -- air pollution -- is down considerably.

He credits work from home policies for that.

People aren't driving to work -- or anywhere else -- while practising social distancing measures, and strict travel restrictions have meant less airplane traffic as well.

"Our biggest emitter, at least in London, is fuel from automobiles, so that is reduced immediately," Mensink said. "Commercial and office buildings are also shut down and so just purely from an emissions perspective, it's been a huge drop."

While Mensink fears a rebound effect could happen once the pandemic is lifted, he's hopeful that it could lead businesses to keep work from home abilities in place, even on a part-time basis.

"I think that's where there could be quite a lasting effect, limiting automobile trips," he said.

"Hopefully it does get people to say: 'Whoa, maybe we don't have to have all this air pollution. How can we keep this going?' This doesn't have to be a temporary stop. Hopefully it leads to something more long lasting."

McGuire isn't quite convinced the steps taken to limit the spread of COVID-19 will benefit the environment in the long run.

"It's still gonna be a fight, I don't think that this pandemic is going to change too, too much ... but there is a bit of hope," she said. "I think people should use this to energize themselves to continue fighting for whatever they were fighting for before, or join the fight."

McGuire also added that the zero-waste "journey" will continue, whether or not plastic bags have to be used in the meantime.

"It's a daily action and a daily choice, but it's really about the long game," she said. "And if you get caught up in the daily guilt of perhaps using a disposable, don't, because it's not worth it. You want the hope of continuing on."

This report by The Canadian Press was first published April 1, 2020.