PM2.5 pollution exceeding Indian standard over a semi-urban region at eastern IGP: Chemistry, meteorological impact, and long-range transport

Sauryadeep Mukherjee; Gyanesh Kumar Singh; Monami Dutta; Vivek Srivastava; Adnan Mateen Qadri; Tarun Gupta; Abhijit Chatterjee

doi:10.1016/j.scitotenv.2023.165415

PM_2.5 pollution exceeding Indian standard over a semi-urban region at eastern IGP: Chemistry, meteorological impact, and long-range transport

Sci Total Environ. 2023 Nov 10:898:165415. doi: 10.1016/j.scitotenv.2023.165415. Epub 2023 Jul 15.

Authors

Sauryadeep Mukherjee¹, Gyanesh Kumar Singh², Monami Dutta¹, Vivek Srivastava², Adnan Mateen Qadri², Tarun Gupta², Abhijit Chatterjee³

Affiliations

¹ Department of Chemical Sciences, Bose Institute, Block-EN, Sector-V, Salt Lake, Kolkata 700091, India; Department of Environmental Science, University of Calcutta, 35, Ballygunge Circular Road, Ballygunge, Kolkata 700019, India.
² Department of Civil Engineering and APTL at Center for Environmental Science and Engineering (CESE), Indian Institute of Technology Kanpur, Kanpur 208016, India.
³ Department of Chemical Sciences, Bose Institute, Block-EN, Sector-V, Salt Lake, Kolkata 700091, India. Electronic address: abhijit@jcbose.ac.in.

PMID: 37459996
DOI: 10.1016/j.scitotenv.2023.165415

Abstract

A year-long study (January-December 2019) on the chemical characterization and meteorological impact on PM_2.5 was conducted over a semi-urban station, Shyamnagar, in the easternmost part of the Indo-Gangetic Plains (IGP). PM_2.5 concentrations (Mean = 81.69 ± 66.27 μgm^-3; 7.10-272.74 μgm^-3), the total carbonaceous aerosols (TCA) (Mean = 22.85 ± 24.95 μgm^-3; 0.77-102.97 μgm^-3) along with differential carbonaceous components like organic carbon (OC) (Mean = 11.28 ± 12.48 μgm^-3; 0.48-53.01 μgm^-3) and elemental carbon (EC) (Mean = 4.83 ± 5.28 μgm^-3; 0.1-22.13 μgm^-3) exhibited prominent seasonal variability with the highest concentrations during winter, followed by post-monsoon, pre-monsoon and lowest during monsoon. A similar seasonal variation was observed for the total water-soluble ionic species (Mean = 31.91 ± 20.12 μgm^-3; 0.1-126.73 μgm^-3). We observed that under the least favorable conditions (low ventilation coefficient), high PM_2.5 pollution (exceeding Indian standard) was associated with a high increase in secondary components of PM_2.5. Eastern, central and western parts of IGP, as well as Nepal, were the major long-distant source regions whereas the northern part of West Bengal and parts of Bangladesh were the major regional source region for high PM_2.5 pollution over Shyamnagar. The ratios like char-EC/soot-EC, non-sea-K⁺/EC and non-sea-SO₄^2-/EC strongly indicated the dominance of fossil fuel burning over biomass burning. Compared with other studies, we observed that the PM_2.5 pollution over this semi-urban region was comparable (and even higher in some cases) with other parts of IGP. The high exceedance of PM_2.5 over the Indian standard in Shyamnagar strongly demands an immediate initiation of systematic and regular based air pollution monitoring over semi-urban/non-urban regions in India, especially IGP, in addition to the polluted cities.

Keywords: Carbonaceous aerosols; IGP; NAAQS; PM(2.5).