Delhi Overtakes Lahore as World’s Most Polluted City as Air Quality Drops
India's capital Delhi overtook Lahore in Pakistan to become the world's most polluted city on Friday, with air quality reaching hazardous levels and visibility dropping as smog blanketed the city of 20 million people. Air quality index (AQI) in Delhi was "hazardous" at 334, making it the most polluted global major city, according to Swiss group IQAir, which measures air quality levels based on the concentration of toxins. An AQI reading up to 50 is considered good with little or no health risk.
