Beijing which is known to be one of the most polluted🏭 cities in the world fares much better when compared to 6⃣ North Indian cities. According to India’s National Air Quality Index(AQI) portal Anand Vihar in Delhi has the worst air quality among the 15 stations which are being analysed in Delhi🌆. Varanasi has the fewest 'clean air days'🌫 in a year (52) followed by Delhi, Faridabad, Agra, Kanpur and Lucknow. In fact, these 6⃣ cities have fared worse than Beijing😳 in 2015 when PM 2.5 data is compared. PM2.5 refers to particulate matter of diameter less than 2.5 micro metres, these are considered highly damaging to lungs.