The air quality of Delhi, Gurugram and Noida improved slightly and was in the poor category on Sunday, according to Central Pollution Control Board (CPCB) data.
The AQI of Delhi is expected to be in poor to very poor category as there has been an increase in stubble burning in neighbouring States, said government-run monitoring agency System of Air Quality and Weather Forecasting and Research (SAFAR).
The AQI of Delhi was 254 and the values for Gurugram and Noida were 273 and 252 respectively, as per CPCBs 4 p.m. bulletin on Sunday, which is an average of the past 24 hours.
An AQI between 0 and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.
The wind speed is forecast to marginally improve for the next two days leading to relatively better dispersion. However, the AQI is predicted to stay in the higher end of poor to the lower end of very poorcategory for next two days. Though fire emission has increased and transport-level wind direction is also favourable, an increase in transport-level wind speed as well as local Delhi surface winds are likely to maintain the stubble contribution in Delhi PM2.5 around the same level, SAFAR said.
The stubble burning fire counts around Haryana, Punjab and neighbouring border regions of Delhi were 1,230 on Saturday, as per SAFAR.
The contribution of stubble burning in the neighbouring States to the PM2.5, a chief pollutant, in Delhi is estimated to be around 17% on Sunday. The wind direction is favourable for transport of pollutants due to stubble burning in other States to the city. Also, the local wind speed is less and this leads to pollutants not getting dispersed easily and in turn, negatively affects the air quality of Delhi.