An improvement in the city’s air quality was noted Monday, with the measure of pollutants dipping a day after it hit emergency levels. However, the 24-hour average air quality index (AQI), recorded by the Central Pollution Control Board (CPCB), continued to remain in the ‘severe’ category at 407. On Sunday, the average AQI reached 494. Kuldeep Srivastava, scientist at the India Meteorological Department (IMD), said, “Wind speed picked up Sunday evening and was recorded at 20 km/hour today, which helped in faster dispersion of pollutants. In addition to this, the sky above Delhi was clear and temperature increased as sunlight started breaking through, which helped in the release of pollutants that were concentrated in the air.” Delhi’s real time AQI improved rapidly by Monday evening, with the CPCB recording it at 376 in the ‘very poor’ category as of 8 pm. Concentration of PM 2.5 and PM 10 also started falling rapidly in Delhi-NCR throughout Monday after reaching an unprecedented peak Sunday, well above emergency levels. As of 7 pm Monday, CPCB recorded PM 2.5 at 290, below the ‘severe’ category of 300, and PM 10 at 398 as against emergency level of 500. On Sunday, PM 2.5 had touched a peak of 560 and PM 10 665.9. Meanwhile, the IMD predicted that a “shallow fog” could be seen Tuesday till 10 am due to an increase in moisture. During this time, visibility would be around 500 to 1,000 metres but wind speed, of west-northwesterly direction, is likely to pick up again as the day progresses, improving air quality further. On November 7, a light shower due to westerly disturbances can be expected as rain clouds are being seen around Delhi. This, coupled with high wind speed, would improve the AQI further, the IMD said.
