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Delhi's Air Crisis: World's Most Polluted Capital
25 Mar
Summary
- Delhi ranked fourth globally and most polluted capital in 2025.
- India hosts three of the five most polluted cities worldwide.
- PM2.5 levels in Delhi are nearly 20 times WHO's safe limit.
In 2025, Delhi was identified as the world's fourth most-polluted city and its capital with the highest pollution levels. The annual average fine particulate matter (PM2.5) concentration reached 99.6µg/m³, significantly exceeding the World Health Organization's safe limit by nearly 20 times.
India featured prominently in the global air quality report, accounting for three of the top five most polluted cities worldwide. Loni in Uttar Pradesh was named the most polluted city globally. Despite a marginal 8% decline in Delhi's annual average PM2.5 concentration from 2024, the city experienced severe monthly spikes.
Nationally, India ranked as the sixth most polluted country in 2025, with an average PM2.5 level of 48.9µg/m³. This reflects a modest 3% decline from the previous year. However, a significant concern remains as 115 Indian cities exceeded the nation's own air quality standards, which are considerably more lenient than WHO guidelines.
