The index is on a scale of 0 to 500 (0 being clean air and 500 being heavy pollution). Outside the US, you can check the World Air Quality Index for air pollution ratings across the globe.

The Air Quality Index in Delhi dropped to 999 over the weekend, making it the most polluted capital city in the world. While the safe limit set by the World Health Organisation is 25, anything ...

Delhi is the 10 most polluted city of the world and the worst air quality index possessing capital in the world. The average annual PM 2.5 concentration of 84.1 micrograms per cubic metre was ...

In the springtime in Oklahoma, allergy season can be a primary cause of stuffy noses or difficulty breathing, but allergens like pollen and ragweed aren't counted on the Air Quality Index as those ...

BANGKOK: Residents of the Thai capital once again face unhealthy air quality today, as IQAir places Bangkok firmly in the top ...