With an average annual PM2.5 concentration of 54.4 micrograms per cubic metre, India has been declared as having the third worst air quality in the world, according to the ‘World Air Quality Report 2023’released recently by Swiss air quality monitoring body, IQAir.

This is a jump of four places from 2022, when, with an average PM2.5 concentration of 53.3 micrograms per cubic metre, India was ranked eighth.

The same report’s list of the most polluted cities/metropolitan areas in the world in 2023 has 42 in the top 50 and 83 in the top 100 from India, led by Begusarai in Bihar, with an average annual PM2.5 concentration of 118.9 micrograms per cubic metre in 2023.

In India, Guwahati and Delhi follow Begusarai, with PM2.5 levels of 105.4 micrograms per cubic metre and 92.7 micrograms per cubic metre.

According to a report on CNN, all but one of the 100 cities with the world’s worst air pollution last year, as per this newly-released study, were in Asia, with the climate crisis playing a pivotal role in bad air quality.

The ‘World Air Quality Report 2023’ ranks countries and cities according to air pollution levels based on the concentration of PM2.5 in the air.

‘PM’ stands for ‘particulate matter’, and ‘2.5’ indicated particles or droplets in the air that are 2.5 microns or less in width. PM2.5 is a common indicator of air pollution.

The World Health Organisation (WHO) reports that around 7 million people die every year due to exposure to polluted air. The WHO’s Air Quality Guidelines state that annual average concentrations of PM2.5 should not exceed 5 micrograms per cubic metre.

The report by IQAir ranks 134 countries and territories.

The top two spots for being the worst air pollutants of 2023 are taken by Bangladesh (79.9 micrograms per cubic metre) and Pakistan (73.7 micrograms per cubic metre). Tajikistan (49 micrograms per cubic metre) and Burkina Faso (46.6 micrograms per cubic metre) come after India.