Every breath counts, but in these cities, it could cost you. According to IQAir’s 2025 World Air Quality Report, which analyzed data from 9,446 cities across 143 countries, these are the 30 urban areas with the worst air pollution on Earth. The numbers next to each city represent the average PM2.5 concentration (µg/m³), tiny particulate matter that penetrates deep into the lungs and bloodstream, posing severe health risks. From industrial smog to dust storms, these cities face a silent crisis.
Click on to see where the air is most dangerous.