The pandemic lockdown leads to cleaner city air across Canada, Concordia paper reveals

February 09, 2021

The COVID-19 pandemic that shuttered cities around the world did not just affect the way we work, study and socialize. It also affected our mobility. With millions of workers no longer commuting, vehicle traffic across Canada has plummeted. This has had a significant impact on the quality of air in major Canadian cities, according to a new study by Concordia researchers.

A paper published in the journal Science of the Total Environment looked at downtown air quality monitoring station data from Vancouver, Edmonton, Saskatoon, Winnipeg, Toronto, Montreal, Halifax and St. John's. It compared the cities' concentration levels of nitrogen dioxide, carbon monoxide and sulfur dioxide measured between February and August 2020 to the figures recorded over the same period in 2018 and 2019. They also used satellite imagery and urban transportation fuel consumption figures to investigate emissions traffic congestion data provided by tracking technology embedded in phones and cars worldwide.

Not surprisingly, the researchers found that emission levels dropped dramatically over the course of the pandemic. The most noticeable drop-off occurred in week 12 of 2020 -- the one beginning Sunday, March 15, when national lockdown measures were implemented.

"We saw traffic congestion levels decrease by 69 per cent in Toronto and by 75 per cent in Montreal, compared to the same week in 2019," says the paper's lead author, Xuelin Tian, a second-year MSc student at the Gina Cody School of Engineering and Computer Science. Her co-authors include fellow student Zhikun Chen, her supervisor Chunjiang An, assistant professor in the Department of Building, Civil and Environmental Engineering, and Zhiqiang Tian of Xi'an Jiaotong University in China.

Less gasoline means less pollution

The paper notes that motor gasoline consumption fell by almost half during the pandemic's early weeks, with a similar, corresponding drop seen in carbon dioxide emissions. Motor gasoline consumption added 8,253.52 million kilograms of carbon dioxide to the atmosphere in April 2019, according to the authors' data. That number dropped to 4,593.01 million kilograms in April 2020.

There have also been significant drops in the concentration levels of nitrogen dioxide in Vancouver, Edmonton, Toronto and Montreal since the beginning of the pandemic. Similarly, concentration levels of carbon monoxide, closely linked to the transportation and mobile equipment sectors, dropped. In Edmonton, carbon monoxide concentration levels fell by as much as 50 per cent, from 0.14 parts per million in March 2018 to 0.07 in March 2020.

Emissions began to grow again over the summer, but the researchers have not yet had a chance to examine data from the second lockdown that began in late fall/winter 2020.

Aside from providing a kind of snapshot of a particularly unusual period, the data can also help governments assess the long-term impact of replacing gas-burning vehicles with electric ones on Canadian city streets.

"This pandemic provided an opportunity for scenario analysis, although it wasn't done on purpose," says An, Concordia University Research Chair in Spill Response and Remediation.

"Governments everywhere are trying to reduce their use of carbon-based fuels. Now we have some data that shows what happens when we reduce the number of gasoline-powered vehicles and the effect that has on emissions."
The Natural Sciences and Engineering Research Council of Canada (NSERC) provided support for this study.

Concordia University

Related Pandemic Articles from Brightsurf:

Areas where the next pandemic could emerge are revealed
An international team of human- and animal health experts has incorporated environmental, social and economic considerations -- including air transit centrality - to identify key areas at risk of leading to the next pandemic.

Narcissists love being pandemic 'essential workers'
There's one group of essential workers who especially enjoy being called a ''hero'' during the COVID-19 pandemic: narcissists.

COVID-19: Air quality influences the pandemic
An interdisciplinary team from the University of Geneva and the ETH Z├╝rich spin-off Meteodat investigated possible interactions between acutely elevated levels of fine particulate matter and the virulence of the coronavirus disease.

People who purchased firearms during pandemic more likely to be suicidal
People who purchase a firearm during the pandemic are more likely to be suicidal than other firearm owners, according to a Rutgers study.

Measles outbreaks likely in wake of COVID-19 pandemic
Major measles outbreaks will likely occur during 2021 as an unexpected consequence of the COVID-19 pandemic, according to a new academic article.

The COVID-19 pandemic: How US universities responded
A new George Mason University study found that the majority of university announcements occurred on the same day as the World Health Organization's pandemic declaration.

Researchers find evidence of pandemic fatigue
A new study from the USC Leonard Davis School of Gerontology shows that the behavioral responses to COVID-19 differed by age.

Excessive alcohol consumption during the COVID-19 pandemic
The full impact of COVID-19 on alcohol use is not yet known, but rates have been rising during the first few months of the pandemic.

How fear encourages physical distancing during pandemic
Despite guidelines plastered on the walls and floors of grocery and retail stores encouraging customers to maintain six-feet of physical distance during the pandemic, many do not.

COVID-19 pandemic and $16 trillion virus
This Viewpoint aggregates mortality, morbidity, mental health conditions, and direct economic losses to estimate the total cost of the pandemic in the US on the optimistic assumption that it will be substantially contained by the fall of 2021.

Read More: Pandemic News and Pandemic Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to