The air quality index (AQI) in Maidan area of Kolkata, often referred to as the 'lungs of the metropolis', has recorded PM 2.5 level at over 100 for four days in a row, triggering concern among a section of environmentalists.
The West Bengal Pollution Control Board (WBPCB), however, allayed fears, contending that the sudden rise in pollution level can be attributed to the retreat of monsoon.
The two automated air monitoring stations at Victoria and Fort Williams showed AQI at 137 (PM 2.5) and 159 (PM 2.5) at 2 pm on Monday, a WBPCB official said.
Over the past three days, the AQI at the two stations hovered between 150 and 200 (PM 2.5), the first time in the past six months, he said.
PM 2.5 refers to the particulate matter suspended in the atmosphere either in solid or liquid form.
Environmentalist Subhas Dutta apprehended that the air quality may go from bad to worse in the coming days, given the changing weather pattern.
"With the monsoon finally leaving, there will be no rain in the days to come and this will lead to further escalation in AQI level," Dutta said.
AQI 100-200 (PM 2.5) level poses moderate threat, causing breathing discomfort to people with lungs, asthma and heart disease.
The WBPCB official said measures were being taken to check air pollution.
"There is nothing to be alarmed over the sudden spurt in AQI level. The sudden change in weather over the past three days, moisture setting in the air and retreat of monsoon are some of the reasons that led to the rise in pollution level.
"We have initiated several measures to check air pollution, the results of which will be apparent in the coming winter days," he added.
Worried over the air quality deterioration, environmentalist S M Ghosh claimed that the rise in AQI in the city was linked to idol immersion and the Red Road Durga Puja Carnival, along with vehicular pollution and weather change, "typical during this time of the year".
Asked for an alternative during the festive season, he said, "In many countries, air ionisers are used to suck dust particles and toxic fumes, but we are yet to see such devices in our city."
Dismissing Ghosh's claims, deputy mayor and chief patron of one of the big-ticket Durga pujas, Atin Ghosh, said some environmentalists are hell bent on stopping festive celebrations in the state.
"They should instead work with the environment department to create public awareness about issues like saving greenery, prohibiting single-use plastic and water misuse," he added.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)