#NewDelhi has been ranked the world's most polluted capital city for s second consecutive year followed by Dhaka (#Bangladesh), N'Djamena (Chad), Dushanbe (#Tajikistan) and Muscat (#Oman). Of the 15 most polluted cities in Central and #SouthAsia in 2021, 12 were in India. New Delhi saw a 14.6 per cent increase in PM2.5 concentration in 2021, 96.4 Ig/m3, up from 84 Ig/m3 in 2020. The annual PM2.5 concentration averages in 48 per cent of India's cities, exceeded 50 Ig/m3 or more than 10 times the #WorldHealthOrganization's (WHO) #AirQuality guidelines.