Report: Canada’s wildfires push Chicago to second most polluted major city in the U.S.
With an unfortunate boost from Canadian wildfires, Chicago’s air quality dropped a notch in 2023, identifying the city as the second most polluted in the United States, according to a leading international company that monitors air quality around the world.
In its 2023 World Air Quality Report, the Swiss technology company IQAir said pollution in the Chicago area is approaching three times the standard recommended by the World Health Organization.
The report found particulate matter concentrations in the city of 13.0 micrograms per meter. The WHO guideline is 5 micrograms. In the 2022 IQAir report, Chicago ranked as the third most polluted major city with concentration levels of 11.8 micrograms per cubic meter.
The measures refer to fine, inhalable pollutants with diameters that are generally 2.5 micrometers and smaller. Scientists refer to these particles as PM 2.5.
The report said Chicago’s increased air pollution can largely be traced to last summer’s Canadian wildfires, which sent smoke sweeping over southern Canada and the northern United States. Winds carrying pollutants across national borders produced a “transboundary haze” that was a major theme of this year’s report, IQAir’s Global CEO Frank Hammes said at a press conference Tuesday.
“We saw the effects of transboundary haze throughout multiple areas in the world, with wildfires in North America during the summer of 2023 being among the most prominent,” Hammes said. “Wildfires in Canada devastated air quality not only in Canada itself, but caused hazardous levels of air quality in the United States, where multiple cities in the Midwest and North East saw significantly increased levels of polluted air.”
Chicago trailed Columbus, Ohio, which topped the U.S. list for most polluted major city for the second year in a row. The cities are followed by Indianapolis, Nashville, Philadelphia and New York City.
The WHO’s guideline is one that’s tough to meet. Only seven countries in the world fall within the limit: Australia, Estonia, Finland, Grenada, Iceland, Mauritius, and New Zealand. Of the 134 countries included in the report, more than 92% exceeded the guideline.
Alongside transboundary haze, climate change was another glaring theme of this year’s report.
“The 2023 World Air Quality Report speaks directly to the link between air quality and climate change. Air pollution and climate change have one major culprit — the use of fossil fuels. Fossil fuel emissions account for 65% of global CO2 emissions and are also a primary cause of the majority of PM 2.5-related deaths,” said Christi Chester-Schroeder, IQAir’s air quality science manager.
Climate change can also alter weather patterns affecting PM 2.5, and with catastrophic weather events becoming more severe and more frequent due to the global warming phenomenon, projections indicate air quality issues will also become more severe, Chester-Schroeder said.
“The easiest way to reduce air pollution is to decrease the use of fossil fuels,” she said.
Hammes added that air quality analysis like IQAir’s annual report is made possible only thanks to air quality monitors hosted by citizen scientists, researchers, community advocates and local organizations.
That’s because while the number of countries with monitoring has increased over the last decade, significant gaps remain in government-operated monitoring.
PM 2.5 can be measured relatively inexpensively and accurately, “not just by governments — but by just about anyone,” Hammes said.
“The global air quality monitoring network needs to be expanded to cover more underrepresented areas so that we can properly address air quality and health impacts wildfires that become more severe due to the effects of climate change,” Chester-Schroeder said.
IQAir describes itself at its website as a company “that empowers individuals, organizations, and governments to improve air quality through information, collaboration, and intervention.”
More information about how to become an air quality contributor can be found at iqair.com/air-quality-community.
• Jenny Whidden is a climate change and environment writer working with the Daily Herald through a partnership with Report For America supported by The Nature Conservancy. To help support her work with a tax-deductible donation, see dailyherald.com/rfa.