Chemical Characterization and Source Apportionment of PM10 Using Receptor Models over the Himalayan Region of India

This study presents the source apportionment of coarse-mode particulate matter (PM10) extracted by 3 receptor models (PCA/APCS, UNMIX, and PMF) at semi-urban sites Indian Himalayan region (IHR) during August 2018–December 2019. In this study, water-soluble inorganic ionic species (WSIIS), organic carbon (WSOC), fractions (organic (OC) elemental (EC)), trace elements PM10 were analyzed over IHR. Nainital (62 ± 39 µg m−3) had highest annual average mass concentration (average standard deviation 1 σ), followed Mohal Kullu (58 32 Darjeeling (54 18 m−3). The total ∑WSIIS order was as follows: (14.02 10.01 > Mohal-Kullu (13.75 10.21 (10.20 6.30 m−3), contributing to 15–30% mass. dominant secondary ions (NH4+, SO42−, NO3−) suggest that strongly influenced anthropogenic sources from regional long-range transport. Principal component analysis (PCA) with an absolute principal score (APCS), Positive Matrix Factorization (PMF) used for identification All three showed relatively similar results profiles all except their number percentage contribution. Overall, soil dust (SD), aerosols (SAs), combustion (biomass burning (BB) + fossil fuel (FFC): BB+FFC), vehicular emissions (VEs) are major identified these sites. Air backward trajectories illustrated PM10, mainly attributed dust-related aerosols, transported Thar Desert, Indo-Gangetic Plain (IGP), northwestern India (i.e., Punjab Haryana) Afghanistan Transported agricultural or residual plumes IGP nearby areas significantly contribute carbonaceous (CAs)