Delhi air quality is now in poor to very poor category. The air quality index improved a bit due to an increase in wind speed. The air quality of Delhi and NCR improved just before Diwali due to widespread rain across Northwest India on November 9 and 10. However, it plunged into the severe category from the night of Diwali due to the bursting of firecrackers. The situation was grim until November 18 as the Meteorological conditions were not favourable for the dispersal of pollutants. Temperatures were low and wind speed was almost calm.
Wind speed has increased marginally leading to the dispersal of pollutants and improvement in the air quality index. We do not expect any significant improvement for another 2 days as the wind speed will not be very high. We expect the speed of winds to increase from November 21st and wind will blow from the northwest direction.
The count of stubble burning has reduced significantly in comparison to last year in the neighbouring states of Punjab and Haryana. The smoke from farm fires will certainly contribute to the pollution of Delhi but its percentage will be much less than the local pollutants.
The government has taken a funny decision. The ban on entry of trucks into Delhi, non-BS-VI compliant light commercial vehicles registered outside Delhi and diesel medium and heavy goods vehicles has been lifted after measures under the GRAP IV were rolled back. GRAP measures under stages I to III, including restrictions on the plying of BS-III petrol and BS-IV diesel LMVs in Delhi-NCR and a ban on construction and demolition activities, will continue. In fact, contribution of the commercial vehicles to the pollutants is much larger than the BS-III petrol and BS-IV diesel vehicles which have the pollution compliance certificate.