Kolkata: Kolkata emerged 15th out of 18 million-plus polluted cities in June within the Indo-Gangetic Plain (IGP), one of the most polluted regions globally, according to an analysis by the Centre for Research on Energy and Clean Air (CREA).
Kolkata’s average PM2.5 count in June was 22 µg/m³, significantly below the national ambient air quality standard (NAAQS) of 60 µg/m³ and slightly above the World Health Organization’s (WHO) standard of 15 µg/m³.The city experienced 27 “good” days (PM2.5 count 0-30 µg/m³) and three “satisfactory” days (31-60 µg/m³) during the month.
Other major cities, such as Chennai, Mumbai and Bengaluru, also maintained PM2.5 concentrations below the NAAQS, with all days in June falling within the “good” category (0-30 µg/m³).
Among the six non-attainment cities in Bengal, Asansol was the only exception, with its average PM2.5 concentration exceeding the NAAQS. On five days in June, Asansol was listed among the top 10 most polluted cities in India.
Across the 18 million-plus cities in the Indo-Gangetic Plain with continuous ambient air quality monitoring stations (CAAQMS) data for more than 80% of the days, five cities—Faridabad, Ludhiana, Asansol, Amritsar, and Delhi—exceeded the NAAQS, said Sunil Dahiya, lead analyst for CREA.
June 2024 saw the installation of four new CAAQMS: one in Pune, two in Asansol, and one in Howrah, increasing the national total to 545 stations.
During the same month, 228 out of 251 cities with more than 80% of the days with CAAQMS data recorded PM2.5 concentrations below India’s daily NAAQS of 60 µg/m³. However, only 33 cities met the WHO’s daily safe guideline concentration of 15 µg/m³.
Rohtak in Haryana ranked as the most polluted city in India in June 2024, with a monthly average PM2.5 concentration of 116 µg/m³, surpassing the daily NAAQS every day of the month. Among India’s top 10 most polluted cities, five were located in Haryana, two in Rajasthan, and one each in Punjab, Assam, and Bihar.
The cities featuring in the daily top 10 most polluted cities list in India were spread across 12 states and union territories (UTs) in June 2024, highlighting the widespread and severe nature of toxic air across the country.
Only 14 out of the 60 cities appearing in the daily top 10 most polluted cities list are part of the National Clean Air Programme (NCAP). The remaining 46 cities lack any action plan to reduce hazardous air pollution levels, according to the study.