Pollutants spike, air quality deteriorates in Gurugram
GURUGRAM: Bursting of firecrackers on Diwali sent air quality in the city plummeting, with Gurugram recording 389 (‘very poor’) on the Air Quality Index on November 8, worse from 212 (‘poor’) recorded Wednesday.
Similar spikes were seen across the National Capital Region, with Delhi’s AQI worsening from 281 to 390, Faridabad from 262 to 455, Noida from 288 to 432, and Ghaziabad from 295 to 422. A day after Diwali, Gurugram was the least polluted among these cities.
However, the deterioration in air quality remained conspicuous. At 2am on Thursday, Gurugram recorded its highest measure of particulate matter 2.5 (PM2.5) this season at 622μg/m3. Just a few hours earlier, at 6pm on November 7, PM2.5 was recorded at 59μg/m3, indicating a tenfold increase in the concentration of the city’s primary pollutant shortly after residents started bursting firecrackers.
Between 9pm and 10pm, which falls within the stipulated window provided by the Supreme Court for bursting firecrackers, the level of atmospheric PM2.5 almost doubled, according to the Central Pollution Control Board (CPCB) data. In 2017, Gurugram recorded an AQI of 398 the day after Diwali.
“This year’s post-Diwali AQI might seem like a marginal improvement, but there was no ban on firecrackers last year and implementation of the Graded Response Action Plan was also not so stringent,” said Kuldip Singh, regional officer (Gurugram), Haryana State Pollution Control Board.
Singh also said that Gurugram recorded slower winds and lower temperatures around Diwali this year. “Last year, the festival was celebrated October 19, when meteorological conditions are more favourable, in terms of reducing pollution. So while there has certainly been a spike in pollution today (Thursday), compared to last year, the situation is not so bad,” he added. Experts agree, but also said that there was no doubt that Thursday’s pollution spike caused due to the widespread use of firecrackers. “Since yesterday was Diwali, emissions from industrial and vehicular sources would have been minimal, leaving only firecrackers as the most reasonable explanation for the increase in airborne pollu-
tants,” said Dipankar Saha, a former member of the Central Pollution Control Board’s air quality lab.
Another monitor in Sector 4 recorded an AQI of 421 (‘severe) at the same time, with PM2.5 at 520μg/m3. Data gathered by a group of independent researchers on Wednesday night reflected PM2.5 levels as high as 1,200μg/ m3 in Sector 81.
The average 24-hour measure of PM2.5 was 407ug/m3 on Thursday at 7pm, up from 212ug/m3 on Wednesday. The safe limit, as per
the National Ambient Air Quality Standards, is 60ug/m3.
Moreover, these pollutants were unable to disperse due to extremely slow wind speeds, which in Gurugram were as low as 1.7kmph in certain areas on Thursday. Wind speeds of at least 10kmph are required for effective dispersal of PM2.5 and PM10.
“Winds are expected to pick up speed to around 4kmph tomorrow (Friday), which might improve the situation,” said Sachin Panwar, a city-based air quality scientist.