Delhi’s air quality entered the poor zone on Wednesday morning for first time since June this year. The air quality index (AQI) reading at 10 am was 207 (in the poor zone), as per Central Pollution Control Board (CPCB) data.
Till Tuesday, the air quality was in the higher end of the moderate category. Government agencies had warned of deterioration in air quality due to the change in weather conditions and fumes from farm fires in neighbouring Haryana and Punjab contributing to pollution in Delhi.
According to the System of Air Quality and Weather Forecasting and Research (Safar), the Central government’s air quality monitoring and forecasting wing, PM 2.5 is usually the main pollutant during winter. “The nighttime calm surface wind condition prevailed yesterday and is likely to do so for the next two days. Further deterioration in air quality is expected by October 9 and 10 but the AQI reading will remain in the poor category. An increase in stubble-burning was observed on Tuesday around Punjab, Haryana, and the neighbouring border regions. The boundary-layer wind direction and speed are favourable for the transport and accumulation of pollutants in Delhi, and the worsening of air quality in the coming days is expected,” the Safar bulletin read.
As per Safar, on October 6, synergised fire count was 336.
After January and February, which had several ‘poor’ category days, only two ‘poor’ category days were recorded each in March, May and June. April, July, August and September had only ‘satisfactory’ and ‘moderate’ days. August was the cleanest month since 2015 when four ‘good’ air days were recorded.
According to scientists at India Meteorological Department (IMD), there has been a consistent dip in the night temperature over the last few days and the wind speed has also slowed down. Besides, the wind (whose direction changed to north-westerly) is bringing fumes from neighbouring states where stubble-burning has started.
On Tuesday, the night temperature was recorded at 18.6 degrees Celsius, three notches below normal while the maximum temperature settled at 36 degrees Celsius, three notches above normal.