Chicago’s Air Quality Plummets to Worst in World, Health Officials Warn

Chicago’s air quality index (AQI) reached “unhealthy” levels on Thursday, ranking as the worst among major global cities due to smoke from western wildfires, according to the U.S. Environmental Protection Agency (EPA). The city’s AQI hit 185, surpassing Los Angeles (160) and Vancouver (170), with officials urging residents to limit outdoor activity.

Smoke from Western Wildfires Drives Pollution Surge

Smoke from wildfires in Oregon and Washington has created a “major air quality crisis” in the Midwest, according to the National Weather Service (NWS). The EPA’s AirNow dashboard shows Chicago’s AQI surpassed 180 by midday Thursday, with particulate matter (PM2.5) levels 10 times higher than the World Health Organization’s (WHO) recommended limit. “This is the worst air quality we’ve seen in decades,” said Dr. Lisa Nguyen, a public health expert at the University of Chicago Medical Center.

Health Advisories Issued for Sensitive Populations

The Illinois Department of Public Health (IDPH) issued a “high health risk” advisory, warning that prolonged exposure could trigger respiratory issues. “People with asthma, heart conditions, or children should stay indoors,” said IDPH Director Dr. Michael Torres. The Chicago Department of Public Health (CDPH) distributed 50,000 N95 masks to schools and clinics, citing a 30% increase in emergency room visits for breathing difficulties since Tuesday.

Global Air Quality Context: How Chicago Compares

While Chicago’s AQI ranks worst among U.S. cities, it lags behind Delhi (220) and Beijing (200) in global comparisons, according to the IQAir 2023 World Air Quality Index Project. However, the city’s rapid deterioration—jumping from 75 on Wednesday to 185 by Thursday—has alarmed local officials. “This is a wake-up call for climate resilience planning,” said Chicago Mayor Brandon Johnson in a statement.

Firefighters Combat Blazes as Smoke Lingers

Over 2,000 firefighters are battling 12 large wildfires in Oregon and Washington, with smoke plumes expected to linger through Saturday. The National Interagency Fire Center (NIFC) reported that 85% of the smoke is originating from the Bootleg Fire in Oregon, which has burned 400,000 acres since July. “We’re seeing unprecedented smoke movement due to high-pressure systems,” said NIFC spokesperson Sarah Mitchell.