Delhi has earned the dubious distinction of becoming the most polluted major city in the world with an air quality index (AQI) of 527 on Friday, as per data by Air Visual on the World AQI rankings.
The Air Visual data is updated frequently, so the caveat is that rankings and AQI counts change accordingly during the day itself.
Delhi air quality broke all records on November 5, when it was in the hazardous range for nine consecutive days, making this the longest spell of hazardous air quality since public records began, according to Air Visual.