Context:

• Swiss organization IQAir has released the ‘World Air Quality Report 2025’ (WAQR 2025). According to the report, only 14% of cities meet the World Health Organization (WHO) annual PM2.5 guideline of 5 µg/m³.
• Key Points:
• Most polluted country: Pakistan ranked as the most polluted country in the world, followed by Bangladesh, Tajikistan, Chad, and the Democratic Republic of Congo.
• The report presents PM2.5 air quality data from 9,446 cities across 143 countries, regions, and territories.
• PM2.5 concentration is reported in micrograms per cubic meter (µg/m³), in line with WHO’s annual air quality guidelines and interim targets.
• The air quality data in this report is derived from IQAir’s real-time monitoring platform, which systematically validates, calibrates, and harmonizes data from monitoring stations worldwide.
• Globally, only 13 countries, regions, and territories met the WHO annual PM2.5 guideline of 5 µg/m³, most of which are located in Latin America and the Caribbean.
• In 2025, wildfire events significantly impacted regions that historically had relatively low PM2.5 levels.
• In 2025, only 14% of cities met the WHO annual PM2.5 guideline, compared to 17% in 2024.

India’s Position:

• • Ranked as the 6th most polluted country among 143 countries.
• • The national average PM2.5 concentration was 48.9 µg/m³, nearly ten times higher than the WHO safe limit of 5 µg/m³.
• • Most polluted city and region: Loni (Uttar Pradesh) was the most polluted city in India in 2025, while New Delhi remained the most polluted capital in the world.
• • 66 out of the world’s 100 most polluted cities are located in India, including major cities such as Delhi, Byrnihat, and Ghaziabad.

Global Findings:

• The five most polluted countries were—Pakistan (67.3 µg/m³), Bangladesh (66.1 µg/m³), Tajikistan (57.3 µg/m³), Chad (53.6 µg/m³), and the Democratic Republic of Congo (50.2 µg/m³).
• Nieuwoudtville (South Africa) was recorded as the cleanest city in the world, with an annual average PM2.5 concentration of 1.0 µg/m³.