Delhi’s air quality ‘very poor’, slow wind speed reduces dispersion of pollutants

Delhi’s air quality remained ‘very poor’ on Sunday as slow wind speed reduced dispersion of pollutants over the city, according to the Central Pollution Control Board (CPCB).

The national capital’s Air Quality Index (AQI) stood at 386 in the morning, a considerable rise from 303 on Saturday, CPCB data showed.

The Air Quality Early Warning System (AQEWS) for Delhi said wind speed dropped below 8 kmph from the northwest direction during the evening and night, reducing the dispersion of pollutants.

A ventilation index lower than 6,000 m²/s and average wind speed less than 10 kmph are considered unfavourable for the dispersal of pollutants, it stated.

According to the AQEWS, the air quality is likely to remain in the ‘very poor’ category till November 4.

17 monitoring stations recorded ‘severe’ air quality with readings above 400. Wazirpur recorded the highest AQI at 439. Twenty other stations reported ‘very poor’ air quality with readings above 300, the CPCB’s Sameer app showed.

An AQI between 0 and 50 is considered ‘good’, 51 to 100 ‘satisfactory’, 101 to 200 ‘moderate’, 201 to 300 ‘poor’, 301 to 400 ‘very poor’ and 401 to 500 ‘severe’.

Delhi recorded a minimum temperature of 16.8 degrees Celsius, 1.5 notches above the season’s average, according to the India Meteorological Department (IMD).

Humidity was recorded at 79 per cent at 8.30 am.

The IMD has forecast mainly clear skies during the day and shallow fog during the night. The maximum temperature is likely to settle around 31 degrees Celsius.