Air quality at ‘moderate’ for first time in three weeks

Air quality in the city improved to the ‘moderate’ category of the air quality index (AQI) for the first time in at least three weeks on Wednesday, with a reading

Air quality in the city improved to the ‘moderate’ category of the air quality index (AQI) for the first time in at least three weeks on Wednesday, with a reading of 146 on the CPCB’s daily pollution bulletin. This was down from Wednesday’s AQI of 204, when the city was engulfed in ‘poor’ air.

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Experts and officials attributed the dip in pollution levels to favourable wind direction and speed, which helped to sustain dispersal of pollutants from Gurugram.

Pollution levels in the city have recorded a sustained decline since November 15. The level of ultrafine particulate matter having a diameter of 2.5 microns or less (PM 2.5), the city’s primary pollutant, was 175 micrograms per cubic metre (µg/m³) on Monday, as per the CPCB’s air quality monitor at Vikas Sadan in Sector 11. This is down from about 399 µg/m³ on November 15. The permissible limit for PM2.5, however, is 60µg/m³.

As a result, Gurugram was the least polluted among other major cities in the National Capital Region (NCR) on Wednesday, with Delhi, Noida, Faridabad, Ghaziabad and Greater Noida all recording ‘poor’ air, with AQI readings in excess of 200. On Tuesday, while Gurugram recorded poor air, other major NCR cities had recorded moderate air.

As per the early air quality warning system for Delhi-NCR, a further dip in pollution levels is expected across the region on Thursday. As per official forecasts, “The air quality in Delhi-NCR is likely to remain in moderate category on 19.11.2020 and moderate to poor category on 20.11.2020.”

Sachin Panwar, a city-based independent air quality scientist, said, “The specific direction of the wind on Wednesday was favourable to Gurugram, which received strong winds from the direct north. The wind speeds also went up from 8 to 10kmph on Tuesday, touching about 12kmph, which helped dispersal of pollutants. The influence of these winds may not have been as much over Delhi and other parts of NCR, which allowed pollutants to accumulate in the capital and places like Noida and Ghaziabad, pushing the air quality there back into the poor category.”

On Wednesday, the city recorded a maximum temperature of 24.1 degrees Celsius, down from 24.6 degrees Celsius a day prior and a minimum temperature of 12 degrees Celsius, down from 14.2 degrees Celsius a day before. As per the weekly IMD forecast, partly cloudy skies are expected to prevail on Thursday. While the maximum temperature is expected to remain between 24 and 26 degrees Celsius over the next week, official forecasts predict that nighttime temperatures will plunge to 10 degrees Celsius by November 24.