Kolkata had a much polluted monsoon this year compared with 2020, according to a report published by the Delhi-based Centre for Science and Environment on Friday.
The report was prepared on the basis of data generated by the Union environment ministry between July 1 and October 14, 2021.
According to an analysis by the environment advocacy organisation, the concentration of highly toxic air pollutant PM (particulate matter) 2.5 in the city’s air increased by 56 per this monsoon (25.14 microgram per cubic metre) compared with the monsoon in 2020 (16.07 microgram per cubic metre).
Kolkata has recorded the maximum rise in the PM 2.5 level between the two monsoons in the state. Except Siliguri, all cities in Bengal have recorded a rise in the PM 2.5 level.
The study, conducted in a number of cities in the Indo-Gangetic plain, shows that Delhi’s PM 2.5 pollution has reduced marginally compared with last year.
PM 2.5 is the ultrafine pollutant that can reach the inner crevices of the lungs and trigger a host of critical diseases, including cancer.
Avikal Somvanshi, one of the experts who prepared the report, told this newspaper that the PM 2.5 level in Kolkata had increased despite the city receiving nearly 43 per cent more rain compared with the last monsoon.
“Under normal circumstances, more rain means more washout of the pollutants and hence, less pollution. The fact that Kolkata has recorded 56 per cent higher PM 2.5 pollution despite having comparatively more rainfall this year, means that the city has generated significantly higher pollution this year,” said Anumita Roy Chowdhury of the CSE, who led the study.
State pollution control board chairman Kalyan Rudra, however, pointed out that the rainfall in the city mostly happened within a short period and was difficult to be correlated with the pollution surge.
“I have not seen the report but we have to keep in mind that many activities resumed this monsoon. Those were suspended during the last monsoon (because of Covid curbs),” the official said.
