India third-most polluted country in world, next only to Bangladesh, Pakistan: report

India was ranked the third-worst country and Delhi the worst capital in the world in terms of the annual average PM 2.5 concentration (microgram per cubic metre) in 2020, as per a report by IQAir which measured the small particles of based on data reported by ground-level monitoring stations in 98 countries.

The annual World Air Quality Report, prepared with support from Greenpeace, UN Environment Programme and other agencies, took into the consideration the sudden drop in the PM 2.5 levels in 2020 caused by Covid-19. It also corrected weather anomalies like the wildfires in Sao Paulo, Los Angeles and Melbourne, before grading the air quality of the countries and their capitals.

India with 51 microgram of PM 2.5 came next only to Bangladesh (77.1) and Pakistan (59). In fact, India's pollution levels have come down compared to 2019 data (58.1), but similar drop was seen in other countries as well.

Similarly, among the most polluted national capitals across the world, New Delhi retained the top spot with the annual average of PM 2.5 concentration at 84.1 microgram/cubic metre, which was less compared to the 98.6 micrograms in 2019.

Within the country, the study of annual average of the small particulate matters in six major cities showed that Chennai was the least polluted with 27.5 micrograms per cubic metre. Bengaluru with 27.5 micrograms stood fifth in the list where Delhi was on top, followed by Kolkata and Mumbai.

The report further noted countries in South Asia need more real-time monitoring to enable more people to respond and protect their health given the severity of the pollution.

The report said there was an overall improvement in several cities in the country. "All cities whose pollution levels increased in 2020, still show an overall downward trend from 2018 and earlier," it said, but noted that air pollution in the country was "still dangerously high".

With 22 of the top 30 polluted cities in the world located in India, the country fares the worst, the report said and flagged transportation, biomass burning, industry and construction among the major contributors for air pollution.