Gurugram sees comparatively cleaner air post Dussehra

A day after Dussehra, on Wednesday, the air quality in Gurugram fell to the ‘moderate’ category after being in the ‘satisfactory’ category for at least three consecutive

A day after Dussehra, on Wednesday, the air quality in Gurugram fell to the ‘moderate’ category after being in the ‘satisfactory’ category for at least three consecutive weeks, showed data from the Central Pollution Control Board’s (CPCB) air quality index (AQI) bulletin.

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On Wednesday, AQI was recorded at 122 by the CPCB’s monitor at Vikas Sadan. Tuesday’s AQI was recorded at 78 (satisfactory). However, Gurugram had the least polluted air among all cities in the national capital region (NCR), where AQI was observed to be in the upper bracket of the moderate category.

Last year, the day after Dussehra had recorded ‘very poor’ air quality, with an AQI reading of 374, as per the CPCB data. Last year’s AQI on the day after the festival was also the season’s most polluted until that day.

According to air quality experts, this year, the AQI didn’t touch extremely harmful levels due to predominant winds blowing a speed of seven kilometers per hour which dispersed a large part of the pollutants.

Sachin Panwar, an independent air quality expert, said, “Winds are blowing at an adequate speed, with a ventilation index sufficient enough to blow away airborne pollutants.” The maximum ventilation index on Wednesday was 7500 m2/s, as per the CPCB. Ventilation index lower than 6000 m2/s, with average wind speed less than 10 kmph, is unfavourable for dispersion of pollutants.

According to officials and experts, the AQI is likely to remain in the moderate category this week. “Though towards the end of the week, we might see the air quality deteriorate and enter the upper end of the moderate category,” said a scientist at the CPCB’s air quality lab in Delhi.

However, with lowering minimum temperature, the AQI could worsen sooner than expected, experts predict. When the minimum temperature drops, pollutants get trapped at a lower level in the atmosphere, leading to a smog-like situation as particles settle closer to the ground at lower mixing heights.

As per the India Meteorological Department (IMD), the minimum temperature is likely to fall to around 18° Celsius in the next few days, from the 20° Celsius recorded Tuesday.