Despite rising temperatures, air quality in Calcutta and Howrah remains hazardous as illegal burning of waste in the open continues unchecked.
At 10am on Sunday, the air quality monitoring stations at Ballygunge, Bidhannagar, Fort William, Jadavpur, Rabindra Bharati University and Victoria reported “poor” air quality.
The station at Rabindra Sarobar reported “moderate” air quality.
By 5pm on Sunday, it had worsened. All seven stations reported “poor” air quality.
Neighbouring Howrah was no better. Three of its five stations reported “poor” air quality on Sunday.
Two stations at Belur Math and Padmapukur reported “poor” air quality at 10am. Ghusuri station reported “very poor” while the stations at Botanical Garden and Dasnagar reported “moderate” air quality. By 5pm, Ghusuri had improved to “poor”, while the others remained unchanged.
An environmental scientist stated that it was challenging to clearly identify the reasons for the poor air quality on Sunday; however, low wind speeds and the build-up of pollutants in the lower atmosphere over several days were contributing factors that have resulted in the air quality remaining below acceptable standards.
“Wind speed is lower in winter months than in summer. The wind helps disperse the pollutants in summer. But in winter, the absence of adequate wind speed traps the pollutants in the lower atmosphere,” said a scientist with the state pollution control board (PCB).
“Also in summer, the air warms up and rises. It carries away the pollutants. In the winter months, the air remains cold and cannot rise as quickly as in summer. The pollutants remain trapped in the lower atmosphere, which is the air we breathe,” said the scientist.
Rain washes away the pollutants during the monsoon.
The maximum temperature on Sunday was 25.2˚C, 0.7 degrees below normal. The minimum temperature, recorded early in the morning, was 13˚C, which was 1.5 degrees below normal.
The minimum temperature dropped to 10.2 degrees Celsius on January 6 and stayed between 10 and 12 degrees for much of early January.
Despite the persistent issue of foul air in winter, the practice of burning waste openly has continued to worsen the circumstances.
A south Calcutta resident said he found a heap of waste burning inside Vivekananda Park on Saturday morning. “There were a lot of amateur footballers, children were training in the cricket coaching camps and their parents. All of them were breathing the toxic air,” he said.
A coach in one of the cricket coaching camps said the fire was burning when he arrived at 6.30am.
“I do not know who lit the waste,” he said.
A few metres away, another heap of garbage on the pavement just outside the boundary of Rabindra Sarobar had been set on fire.
“This is a neighbourhood where so many people come for a morning walk. Burning waste here actually impacts so many people,” said the south Calcutta resident.
Open burning of waste is prohibited by law. There are orders by the Kolkata Municipal Corporation (KMC) banning the open burning of garbage.
“It is difficult to spot who sets waste on fire. There are provisions for imposing a penalty on those who burn waste in the open, but identifying people doing so is not easy,” said a KMC official.
Both heaps of garbage contained plastic waste.
The PCB scientist said that any accumulation of trash consistently contains plastic, given the pervasive nature of plastic in modern existence. Burning plastic at lower temperatures, which happens when it is set on fire outdoors, is hazardous.
“When plastic is burnt in the open at low temperature, it releases toxic chemicals like furan and dioxin, which are carcinogenic. Anyone with prolonged exposure to the polluted air will be impacted,” said the scientist.
The combustion of waste, even without the presence of plastic, generates particulate matter that increases air pollution.
He mentioned that the waste that has been burned is spread by the wind, which again leads to air pollution.