Understanding Sources and Composition of Black Carbon and PM2.5 in Urban Environments in East India

Abstract

Black carbon (BC) and PM2.5 chemical characterizations are crucial for insight into their impact on the health of the exposed population. PM2.5 sampling was carried out over selected residential sites of Jamshedpur (JSR) and Kharagpur (KGP), east India, during the winter season. Seven selected elements (SO42−, Cl−, Na+, NO3−, K+, Ca2+, and Mg2+) were analyzed using ion chromatography (IC). Black carbon (BC) sampling was also done at two different sites in JSR and KGP to understand its correlation. The PM2.5 ionic species mass concentration in JSR was in the order of SO42− > Cl− > Na+ > NO3− > K+ > Ca2+ > Mg2+, whereas in KGP, it was SO42− > NO3− > Cl− > Na+ > K+ > Ca2+ > Mg2+. The back-trajectory analysis showed that most of the air masses during the study period originated from the Indo Gangetic Plain (IGP). The Pearson relations of BC-PM2.5 indicate a better positive correlation (r = 0.66) at KGP compared to JSR (r = 0.42). As shown in the diagnostic ratio analysis, fossil fuel combustion and wood burning account for 51.51% and 36.36% of the total energy consumption in JSR city, respectively. In KGP city, the apportionment of origin sources were fossil fuel and wood burning at 43.75% and 34.37%, respectively. This study provides the first inventory of atmospheric particulate-bound chemical concentrations and BC profiles in middle-east India and informs policymakers and scientists for further studies.