Characterization and source attribution of PM2.5 in a coal mining town in India: Insights from residential and
Kamlika Gupta1, Victor Wei-Chung Chang2, Mohan Yellishetty2
1IITB-Monash Research Academy, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, - 400076, India; Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, - 400076, India; Department of Civil and Environmental Engineering, Monash University, Melbourne, Victoria, 3168, Australia.
Abstract:
India's continued reliance on coal for power generation, steel, and cement production results in substantial emissions of fine particulate matter (PM2.5) and associated chemical species, particularly in densely populated industrial and mining regions. Characterizing PM2.5 composition and its sources is critical for accurate exposure assessment and targeted mitigation of environmental and climate impacts. This study investigates the chemical composition of PM2.5 at roadsides and residential sites within a major opencast coal mining region in Western India and attributes its sources using Absolute Principal Component Analysis-Multiple Linear Regression (APCS-MLR). PM2.5 was highest at the mining roadside (546 ± 182 μg m-3), city road (363.6 ± 105 μg m-3), and residential locations which were located 2 and 5 km from the mine (122 ± 43 μg m-3 and 116 ± 36 μg m-3, respectively). Carbonaceous components contributed 10-20 % to PM2.5, with organic carbon (22.82 ± 12.65 μg m-3) nearly two-fold higher than elemental carbon (9.68 ± 5.68 μg m-3). Ions (20-30 % of PM2.5) were dominated by chloride, sulfate, ammonium, potassium, and nitrate. Crustal metals associated with non-exhaust, coal, and industrial activities were two-fold higher at roadside locations, compared to residential sites. Benzo(a)pyrene dominated the PAHs fraction (19.7 ± 5.2 μg m-3), and diagnostic ratios revealed a mix of pyrogenic and petrogenic sources. Major source categories identified were non-exhaust/crustal/industrial (56 %), vehicular and coal-combustion (36 %), and biomass burning/secondary aerosols (7 %). Vehicular fleet characterization showed a predominance of heavy-duty diesel vehicles along mining transport corridors and mixed fleet traffic on the urban road. Overall, the results highlight mining-associated vehicular transport, dust resuspension, secondary aerosols, and regional combustion sources act as key drivers of PM2.5 in this mining region. This underscores the need for targeted, source-specific, and multi-pollutant mitigation strategies that extend beyond conventional dust control in mining-dominated regions.
