Thick smoke from Canadian wildfires has propelled three major U.S. cities to the top of global air quality rankings, making them the most dangerous places to breathe worldwide.
On Thursday, Detroit, Minneapolis, and Chicago occupied the top three positions on IQAir's live global ranking of cities with the worst air quality. Detroit registered an Air Quality Index (AQI) of 566, surpassing cities in South Asia that typically experience the most severe pollution.
Minneapolis followed with an AQI of 289, and Chicago was third at 259. According to the U.S. AQI scale, readings above 300 are classified as "hazardous," indicating serious health risks for everyone. Readings between 201 and 300 are considered "very unhealthy," warning of adverse effects from prolonged exposure.
Officials have identified fine particulate matter, known as PM2.5, within the wildfire smoke as the primary concern. These microscopic particles are small enough to penetrate deep into the lungs and enter the bloodstream.
State and local health officials across the affected cities have issued air quality alerts, advising residents to limit outdoor activities until conditions improve. Recommendations include avoiding strenuous exercise, staying indoors with windows and doors closed, and using HEPA air purifiers. Burning candles or using fireplaces indoors is also discouraged, as it can worsen indoor air pollution. The use of well-fitting N95 or KN95 masks is advised for those who must go outside.
Individuals at higher risk, including those with pre-existing respiratory or heart conditions, children, pregnant women, and older adults, are urged to avoid outdoor exertion and adhere to their medication plans.
The air quality alert in the Detroit metro area was extended into Friday, with pollutants expected to remain in the "very unhealthy" to "hazardous" range. Breathing the air in Detroit on Thursday was estimated to be equivalent to smoking a pack of cigarettes.
Residents in affected areas reported experiencing symptoms such as headaches and irritation to the eyes and throat, even when wearing masks. The dense smoke has significantly reduced visibility, with some residents noting that downtown skylines were obscured.
