Delhi tops India in PM2.5 pollution; 447 districts exceed national air quality limit: Report

New Delhi, Delhi is the most polluted state. Its annual PM2.5 concentration is 101 micrograms per cubic metre. This is 2.5 times the Indian standard. Chandigarh is second. Many districts across India exceed air quality standards. Delhi and Assam have the most polluted districts. This analysis uses satellite data from March 2024 to February 2025.