Delhi’s air quality stays in the ‘very poor’ zone

The 24-hour average air quality Index (AQI) stood at 391 (very poor) at 4 pm, when the Central Pollution Control Board releases its daily national bulletin. It was 392 at 4 pm on Wednesday and 374 on Tuesday. The AQI had briefly breached 400 post midnight on Thursday, before marginally dipping during the day.

Delhi’s air quality was on the brink of ‘severe’ on Thursday as calm winds and low temperature led to stagnation and accumulation of pollutants. A thick haze continued to engulf the city, keeping visibility low and making breathing difficult.

The 24-hour average air quality Index (AQI) stood at 391 (very poor) at 4 pm (RAJ K RAJ /HT PHOTO)

The 24-hour average air quality Index (AQI) stood at 391 (very poor) at 4 pm, when the Central Pollution Control Board releases its daily national bulletin. It was 392 at 4 pm on Wednesday and 374 on Tuesday. The AQI had briefly breached 400 post midnight on Thursday, before marginally dipping during the day.

Forecasts by the Centre’s Air Quality Early Warning System (EWS) for Delhi show the capital’s AQI is likely to stay ‘very poor’ on November 21, but should deteriorate to ‘severe’ on November 22 before marginally improving to ‘very poor’ again on November 23.

The CPCB classifies air as ‘good’ when the AQI is 50 or lower, as ‘satisfactory’ when it is between 51 and 100, as ‘moderate’ when it is between 101 and 200, as ‘poor’ when it is between 201 and 300, as ‘very poor’ when it is between 301 and 400 and ‘severe’ when it is over 400.

Of the city’s 39 ambient air quality monitoring stations, 20 were in severe on Thursday. The worst impacted was Wazirpur — with a reading of 476, followed by Jahangirpuri (451). CPCB’s AQI maxes out at 500.

“Winds continue to remain low and though the minimum has marginally increased, overall, we are not seeing dispersion of pollutants,” said Mahesh Palawat, vice president at Skymet. So far, Delhi has logged three severe air days this winter — from November 11-13.

Delhi’s minimum temperature stood at 11.4°C, which was a degree below normal. It was 10.2°C a day earlier. Forecasts show the minimum is likely to hover between 11-13°C on Friday and between 10-12°C over the weekend. The maximum stood at 28.2°C, which was around normal. This is likely to oscillate between 25-27°C over the weekend, the India Meteorological Department (IMD) has said. It has also forecast shallow fog to persist in the early hours of the day.