Chicago Tops Major Cities for Worst Air Quality

The pollution from Minnesota and Canadian wildfire smoke had Chicago, Minneapolis, and Detroit ranked in the top three most polluted major cities in the world on July 16, according to an international air quality monitoring website. Chicago was No. 1 by mid-afternoon that day.

The Illinois Environmental Protection Agency also declared an Air Pollution Action Day for the region, urging everyone to limit outdoor exposure.

Fine particles known as PM2.5, which can be emitted by pollution sources such as factories, power plants, diesel and gasoline vehicles, residential fireplaces, and wildfires, are the main driver behind July 16’s elevated air quality in Chicagoland, the Daily Herald reported. PM2.5 can harm human health and sometimes be deadly. Initially, fine particulate matter may cause a burning sensation in the eyes and nose, and because of its small size, it can settle deep in the lungs and cross into the bloodstream.

As health officials urged people to check the Air Quality Index (AQI) before heading outside, AccuWeather reported that doctors say one comparison can help explain just how unhealthy the air can become: cigarettes. Neither wildfire nor cigarette smoke exposure are good, doctors said. PM2.5 also can be found in cigarette smoke and are among the biggest health concerns during smoky air outbreaks. Additionally, scientists have reported that an air quality reading of about 20 on the AQI scale is roughly like smoking one cigarette a day. When the AQI climbs into the 150-plus range for a full day outside, that’s in the range of seven to nine cigarettes. On July 16, Chicago’s AQI tracked higher than 400.

As CMM reported earlier this month, Colorado health officials urged residents to check air quality resources and warned that smoke conditions can change quickly depending on fire activity, wind, and weather.