Kolkata was the second most polluted metro city in India and 60th most polluted city in the world in 2021.
The city’s annual PM (particulate matter) 2.5 level, the most toxic ultrafine particulate, was nearly 12 times above the limit set by the World Health Organization, says a recently released international report on air pollution.
The 2021 World Air Quality Report is prepared by IQAir, a Swiss organisation working on air quality, based on PM 2.5 air quality data from 6,475 cities in 117 countries, regions and territories around the world.
The chart showcased in the report shows that Kolkata’s PM 2.5 level was 59 micrograms in 2021, a 26 per cent increase over 2020 PM 2.5 level of 46.6 micrograms, which was less than Delhi (96.4 micrograms) in gross value but much higher than the rest of Indian metros.
But Kolkata’s rise in average PM 2.5 level during 2021 was highest among all Indian metros with Delhi rising about 15 per cent, Mumbai by 8 per cent while Chennai and Bangalore almost remaining unchanged from 2020.
PM 2.5, ultrafine particulate that can enter deep in the lungs, is one of six routinely measured air pollutants and commonly accepted as the most harmful to human health. WHO has set an annual limit of 5 micrograms.
The report stated that the Indian subcontinent was the most polluted region of the world during 2021; with India occupying fifth most polluted country position with Bangladesh being global topper and Pakistan occupying third position.
India’s average PM 2.5 level increased to 58.1 micrograms in 2021 — ending a three-year trend of improving air quality. It was 72.5 micrograms in 2018 and declined to 58.1 micrograms in 2019, 51.9 micrograms in 2020, it stated.
“The finding has cast a shadow over the ambitious National Clean Air Programme (NCAP) launched in 2019 that seeks to reduce PM concentrations by 20 to 30 per cent by 2024,” said an expert
The report found that four out of top five most polluted cities were in India. Bhiwadi in Rajasthan topped the global chart while Delhi was the fourth most polluted city in the world.
“Kolkata has to scale up its implementation among all possible sources of pollution with special focus on vehicle, construction, open burning of waste and informal sectors,” said Anumita Roy Choudhury, air pollution expert from environmental think-tank Centre for Science and Environment.
“The report has highlighted how we are back on the pollution path. Unless the government takes immediate actions and brings CNG vehicular fuel in the city, it is only bound to worsen further,” said environment activist Subhas Datta.
“There was bound to be some increase in 2021 once the lockdown got diluted but we are still much better than pollution levels of 2017-18,” said a senior environment department official.