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City Average Particulate Air Pollution (PM2.5)

Most Polluted Cities

Least Polluted Cities

All numbers are PM2.5 concentrations in μg/m3. City averages are based on regionally interpolated real-time monitoring station data. Individual neighborhoods and/or monitoring sites in the city may have somewhat more or less pollution. Only cities with at least 250,000 residents are included, and then only if real-time air quality monitoring data is available. Real-time data may contain errors and is subject to revision. Colors based on United States EPA Health Guidelines.