KOLKATA: Air quality index hovered between 100 and 150 (PM.25) in Kolkata on Monday morning a spike from 'satisfactory' to 'moderate' level hours after people burst crackers, in response to the prime minister's call to light lamps to display collective resolve against COVID-19.
The US Consulate Air Monitoring unit, near Park Street, read 151 AQI at 10 am up from 139 on Saturday.
An hour after the 9 pm-9 minutes initiative on Sunday, the AQI level was at 156.
An official at the West Bengal Pollution Control Board official told PTI that the AQI stood at 94 (PM 2.5) at the Fort William air monitoring unit, minutes before people turned the PM's solidarity call into an occasion for frenzied celebrations, amid the lockdown.
Around 11 am on Monday, the AQI level at the Fort William unit touched 101.
Similarly at Rabindra Sarobar, too, the AQI stood at 102 (PM 2.5) at 11 am an abrupt increase from 70 at 9 pm on Sunday evening.
"Air quality had substantially improved in the city over the past week, amid the lockdown imposed by the government over the growing COVID-19 threat, as industries suspended operations and vehicles kept off the roads.
The bursting of crackers, however, led to temporary concentration of respirable particulate matter in the air in certain pockets of the city and that would take time to dissipate," the official said.
He, however, hoped that the AQI level will climb down to 'satisafactory' level again over the next 24-48 hours, with the lockdown still in force.
Environmentalist Somendranath Ghosh, however, said that the harmful pollutants released by the crackers often take days to die down.
"Burning of any object causes immense air pollution. Even 10 minutes of cracker bursting could trigger pollutants that remain suspended in the air for several days," Ghosh added.