"Smoke from Canada Wildfires Causes Chicago's Worst Air Quality on Record"

Chicago experienced the worst air quality in the world on Tuesday due to heavy smoke from Canadian wildfires, with the World Air Quality Index issuing warnings. The smoke caused dangerously low air quality levels, equivalent to smoking eight cigarettes a day, and prompted the city to advise residents to wear masks, limit outdoor activities, and close windows. The hazy air led to the closure of beaches, cancellation of events, and relocation of summer programs indoors. Individuals, especially those with respiratory conditions, were urged to watch out for symptoms such as shortness of breath and seek medical attention if necessary. Detroit and Minneapolis also had high levels of air pollution.