With Strong winds pushing the capital’s air quality from ‘poor’ on Wednesday to ‘moderate’ on Thursday, Delhi saw its first December day with moderate air quality since 2015, as per Central Pollution Control Board data. The Air Quality Index on Thursday read 194 at 4 pm, putting the air in the ‘moderate’ range. It was 282 on Wednesday, which falls in the ‘poor’ category.
“Meteorology and our ground level activities have taken care of air pollutants in Delhi-NCR and surrounding areas. As a result, we had moderate AQI for the first time in December since 2015.The weather conditions mean a clear sky and higher vertical area for dispersion of pollutants. Better wind speed also means horizontal dispersion of pollutants. We are expecting moderate AQI for next few days,” said Dipankar Saha, head of the air quality laboratory at CPCB.
December and January are the most polluted months of the year in north India, as temperatures and wind speed are low. Both factors promote the accumulation of pollutants. These are also the driest months, which means there is no way to wash away pollutants. At Mandir Marg on Thursday, for example, wind speed touched 3.6 m/second at around noon and continued in the range of 3 m/second to 2 m/second till 4 pm. In the corresponding time, the PM 2.5 concentration dropped to 70 µg/m3. It dipped to 32 by 5.30 pm.
At Anand Vihar, which is among the most polluted areas, the wind speed touched a maximum of 1.8 m/second at around 3 pm, the highest for the day. PM 2.5 concentration for the corresponding time was recorded as 65 µg/m3. It fell to 56 by 5.30 pm. According to the SAFAR forecast, air quality is expected to be similar on Friday and Saturday as well.