2026-03-01 ENVIRONMENTAL SUSTAINABILITY 2026 9(卷), 1(期), (131-152页)
Microplastics have become a pressing global environmental issue; however, their behavior and impacts in terrestrial environments, particularly in arid and semi-arid regions, remain inadequately explored. Addressing this gap, the present study investigates road dust as a significant carrier of microplastic pollution in Jaipur, a semi-arid city in India. It evaluates the influence of climatic factors on microplastic distribution, providing new insights into their transport and accumulation dynamics. A total of 60 road dust samples were collected from diverse land-use areas, including industrial, commercial, residential, and highway zones across the city. After organic matter digestion and density separation, samples were quantified for microplastic using Nile Red fluorescence microscopy and characterized through Raman spectroscopy and scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDS). The findings revealed an average microplastic abundance ranging from 362.07 +/- 84.48 to 213.47 +/- 74.98 particles per 100 g of road dust, with most particles measuring under 300 mu m. Fibers emerged as the most dominant shape, while the most commonly detected polymers were polyethylene (29%) and polypropylene (27%). The microplastic pollution load index indicated moderate to severe contamination levels across the study area. Exposure assessment showed that children are at a higher risk of microplastic intake under normal and acute exposure scenarios than adults. Statistical analyses, including principal component analysis (PCA) and Pearson's correlation, demonstrated moderate to strong positive correlations between microplastic abundance and environmental variables such as relative humidity, wind speed, temperature, and fine particle size. Moreover, cluster mean backward-trajectory analysis indicated that approximately one-fourth of microplastics in road dust originated from local sources. In conclusion, the substantial presence of microplastics in Jaipur's road dust highlights its role as a significant reservoir of microplastics and underscores the need for integrated environmental monitoring strategies to address potential public health risks. This study broadens the geographical scope of microplastic research, offering valuable baseline data for risk assessment and policy development in semi-arid urban environments.