Begusarai, Bihar, emerges as the world’s most polluted metropolitan area, while Delhi retains its title as the capital with the worst air quality. India ranks third globally in air pollution, with an average PM2.5 concentration of 54.4 micrograms per cubic meter in 2023. Delhi’s PM2.5 levels worsened to 92.7 micrograms per cubic meter. Over 1.36 billion Indians exceed WHO’s recommended PM2.5 levels. Air pollution contributes to one in nine deaths worldwide, causing severe health issues like asthma and cancer. The report, based on data from over 30,000 monitoring stations, highlights the urgent need for air quality improvement measures.