Delhi's AQI nears the severe mark as India Gate records 399 and the city logs its worst reading in 288 days. Stubble burning, vehicle emissions and PM2.5 pollution raise fresh health concerns ahead of Diwali. Delhi's overall AQI reached 377, its worst reading in 288 days, while India Gate recorded 399 on Thursday morning.Stubble burning contributed 20.2 per cent of Delhi's pollution, compared with 15.5 per cent from transport emissions.