Investigating PM2.5 Oxidative Potential and Its Association with Chemical Constituents Measured outside of Urban Residences in Three Metropolitan Cities of India

Background: )] have been suggested as one of the major sources of oxidative stress- and health-related disorders in the urban population. Objectives: (traffic emissions, commercial, and residential activities) in three metropolitan Indian cities. Methods: outside balconies, ground floors, and first floors of residential buildings for 24 h. We used acellular assays, including dithiothreitol (DTT) and ascorbic acid (AA), to examine the particle toxicity. Bivariate and multiple linear regression analyses were conducted to examine the association of OP with the analyzed PM constituents. Results: levels were observed in both seasons, winter and summer, suggesting that toxicity is more likely influenced by the primary-originated traffic aerosols. Water-soluble organic carbon, cobalt (Co), and vanadium (V) were the primary contributors to reactive oxygen species activity. Discussion: Our study reveals that PM toxicity outside of residential homes in traffic-dominated neighborhoods is significant compared with other neighborhoods across all metropolitan cities. This emphasizes the potential health risks associated with PM originating from traffic sources. https://doi.org/10.1289/JHP1007.