Delhi's Hazardous Air Quality Persists Despite Temporary Improvements

Despite remaining classified as hazardous, Delhi has reopened schools and some building sites as air pollution levels recede. However, the city continues to battle toxic foam in the Yamuna river, caused by sludge and untreated waste. The foam is described as toxic but not lethal, although it can cause illness. Delhi's air quality index (AQI) has improved from 509 to 336, but still remains hazardous. Traffic emissions, particularly from vehicles, contribute significantly to the dangerous PM2.5 particles suspended in the air. The government's early warning system predicts a further decrease in AQI over the next two days due to increased wind speeds.