Source Identification of Ambient PM 2.5 and VOCs in a Complex Urban–Industrial Environment of India: Application of Receptor Modeling

This study aimed to estimate source contributions to ambient fine particulate matter (PM 2.5 ) and volatile organic compounds (VOCs) measured at Raipur, Central India, during the periods of October 2015–September 2016 and November 2021–June 2022. Chemical compositions (15 elements, nine water-soluble ions, organic carbon [OC], and elemental carbon [EC]) for 164 PM 2.5 filter samples and 120 absorbent samples (21 VOCs) were used as input to receptor models (USEPA UNMIX 6.0 and PMF 5.0 models) for source apportionment. The results revealed four PM 2.5 source types and average relative source contributions: (1) road traffic (29.7%), (2) industrial emission (25.4%), (3) biomass burning (24.0%), and (4) coal combustion (20.9%). Average VOC source attributions were (1) vehicle engine exhausts (37.7%), (2) biomass burning and coal combustion (20.3%), (3) industrial emission/solvent usage (34.1%), and (4) biogenic emissions (7.90%). Nineteen locally derived PM 2.5 chemical source profiles for road traffic, domestic heating, and industrial emissions were used with the EV-CMB 8.2 model for comparison with PMF results, yielding similar source contributions.