39 of world's 50 most polluted cities In India

New Delhi:  India was the world's eighth most polluted country in 2022, dropping from fifth place the previous year. While the PM 2.5 level has dipped to 53.3 micrograms/cubic metre, that is still over 10 times the World Health Organisation's safe limit. 39 of world's 50 most polluted cities are in India

The ranking was decided by Swiss firm IQAir in its 'World Air Quality Report' released on Tuesday. It is based on the level of PM 2.5, a pollutant closely tracked by scientists and health experts.  The data from 131 countries is taken from over 30,000 ground-based monitors, either government or non-government operated.

Indian cities dominate the top of the list which includes over 7,300 cities, the most the rankings have ever covered since 2017 when it covered less than 2,200.  he report puts the economic cost of air pollution in India at $150 billion, with the transportation sector causing 20-35 per cent of the PM 2.5 pollution. Other sources of pollution are industrial units, coal-fired power plants and biomass burning.

Delhi has so far been the most polluted capital in the world but this year the report has made a distinction between 'greater' Delhi and New Delhi the capital. Both are in the top 10 but New Delhi is ranked 2nd and the infamous distinction of being the world's most polluted capital goes to Chad's N'Djamena.

But there may be a silver lining: Delhi's next-door towns of Gurugram, Noida, Ghaziabad and Faridabad have seen a decline in pollution levels - from 34 per cent in Gurugram to 21 per cent in Faridabad, compared to the average PM 2.5 levels reported in previous years. Delhi has dipped barely 8 per cent. But the actual levels of pollution in these cities are far higher than the Indian average. While Ghaziabad's PM 2.5 average for 2022 is over 88 micrograms, Gurugram's is 70.