Pakistan, Jan. 21 -- Lahore has once again become the world's most polluted city, with its air quality reaching "hazardous" levels. The city recorded an Air Quality Index (AQI) of 452 on Wednesday, ...

Data: American Lung Association; Note: Days where air pollution was worse received a greater weighting in the calculation; Chart: Alex Fitzpatrick/Axios Houston continues to be one of the most ...

NEW DELHI – After Diwali celebrations filled the skies with firecrackers and festive smoke, the Commission for Air Quality Management on October 21 reported an alarming deterioration in air quality ...