Plastic rain-Atmospheric microplastics deposition in urban and peri-urban areas of Patna City, Bihar, India: Distribution, characteristics, transport, and source analysis.

Evidence of atmospheric microplastics (MPs) deposition in India is scarce though reports of MPs pollution in other environmental media exist. Henceforth, this study for the first time examines and compares the abundance, characteristics, transport, and source analysis of atmospheric MPs in the urban and peri-urban areas of Patna city, Bihar, India. Wet atmospheric fallout samples were collected and analyzed for MPs deposition rate. The results showed that the mean MPs concentrations at each site were 1959.6 ± 205 (urban) and 1320.4 ± 126 (peri-urban) MPs/m/day. The deposited MPs were mainly transparent fibers and fragments with a mean size of 347.9 ± 189.2 µm. Polyethylene terephthalate and polypropylene were the most abundant polymer found at both sites. Morphological characteristics revealed surface degradation and deposition of metal contaminants on the identified MPs. Meteorological parameters (wind direction and rainfall intensity) were significantly associated with the distribution of atmospheric MPs in the study area. The cluster mean backward trajectory suggested vehicular emissions, construction activities, and waste mismanagement as the potential sources of MPs. Findings of the present work necessitates future studies in gaining a deeper understanding of the fate, movement, and potential health hazards associated with atmospheric MPs.