Delhi’s air quality has plunged this week, with dense smog on Wednesday making the Indian capital the most polluted city in the country for the third day in a row.
A thick blanket of pollution covered the city, reducing visibility, as local measurements for the Air Quality Index (AQI) soared above 440, forcing authorities to reinstate the most stringent measures under a pollution control programme known as the Graded Response Action Plan (Grap).