New Delhi, March 24 -- India's Loni earned the dubious distinction of being the world's most polluted city with alarming PM2.5 levels, according to an IQAir report released on 24 March. According to the World Health Organization (WHO) recommendations, the concentration of this hazardous air pollutant was below 5 micrograms per cubic metre last year. This implies that Loni's PM2.5 level is almost 22 times the prescribed limit.

A total of five Indian cities were among the top 10 most polluted cities in the world, including Uttar Pradesh's Loni and Meghalaya's Byrnihat, followed by Delhi, Ghaziabad and West Bengal's Ula (Birnagar). In the second spot in the list is China's Hotan. Four cities in Pakistan also appear on the list of the "World...