Why in News?

• Recently, World Air Quality Report prepared by IQAir, Delhi ranked 4^th out of 50 of the world’s most polluted cities in terms of PM2.5 levels in 2022.

Highlights

• IQAir, a Swiss air quality technology company, prepares the annual world air quality reports based on data from monitoring stations operated by governments and other institutions and organisations across the world.
• The 2022 report Is based on PM2.5 data from 7,323 cities and 131 countries.
• Chad, Iraq, Pakistan, Bahrain, Bangladesh are the 5 most polluted countries in 2022.
• Delhi had an average PM2.5 level of 92.6 μg/m3 in 2022, a little below the average of 96.4 μg/m3 in 2021.
• The report makes a distinction between New Delhi and Delhi, with New Delhi having an annual average PM2.5 level of 89.1 μg/m3.
• The WHO guideline for annual PM2.5 levels is 5 μg/m3.
• Lahore was the most polluted city in the world, followed by Hotan in China, and Bhiwadi in Rajasthan.
• New Delhi is the second most polluted capital city in the world, with N’Djamena in Chad topping the list.
• A total of 39 Indian cities (including ‘Delhi’ and ‘New Delhi’) are on the list of 50 of the world’s most polluted cities based on annual average PM2.5 levels in 2022.