Why in News? 

• According to the 2024 World Air Quality Report, Delhi recorded an average PM2.5 concentration of 91.8 μg/m, making it the most polluted capital city globally. 

About  

• It is an annual publication by the Swiss organization IQAir and assesses the global air quality status. 
• It compiles PM2.5 air quality data from 8,954 cities across 138 countries, regions, and territories. 

India-Specific Findings 

• Delhi remains the world's most polluted capital city with an average PM2.5 level of 91.8 μg/m³. 
• 13 of the 20 most polluted cities globally are in India, with Byrnihat (Assam-Meghalaya border) being the most polluted. 
• Other highly polluted Indian cities include Faridabad, Loni (Ghaziabad), Gurgaon, Greater Noida, Bhiwadi, Noida, Muzaffarnagar, New Delhi, Delhi  

India’s Pollution Ranking 

• India ranks as the fifth most polluted country in the world. 
• The country’s average PM2.5 concentration is 50.6 μg/m³, which is 10 times higher than the WHO’s annual guideline of 5 μg/m³. 
• In 2023, India was the third most polluted country, indicating a slight improvement in ranking.