Pollution levels in Delhi, which remained choked with toxic air on Monday, will start improving only on Wednesday. According to System of Air Quality and Weather Forecasting and Research (SAFAR), Delhi’s air will remain in the ‘severe’ range on Tuesday and will improve — to ‘very poor’ — on Wednesday with an increase in wind speed. A mix of Diwali crackers, high humidity, low temperature and low wind speed in Delhi meant that pollutants got accumulated in the air. A relatively high wind speed dispersed pollutants, but it has been in the range of 0.3 metres per second and 2 metres per second since Saturday. Usually, it is between 2 metres per second and 4 metres per second in the capital.