Abstract：
Microplastic has emerged as a global threat owing to its chronic ubiquity and persistence. Microplastics\' small size expedites their ingestion at each trophic level causing biomagnification and bioaccumulation, which has raised public concerns. The present study isolated, quantified and characterized the abundance, shape, size, color, and chemical composition of the microplastics from water and sediments of the Hirakud Reservoir through a scanning electron microscope and FTIR. The ecological risk associated with the microplastics was assessed using the species sensitivity distribution (SSD) method to derive the Predicted No-Effect Concentration (PNEC) value and risk quotient (RQ). The abundance of microplastics in the surface water and sediments of the Hirakud Reservoir was estimated at 82-89 particles/L and 159-163 particles/kg, respectively. Fiber-shaped microplastics dominated both surface water (46.21%) and sediment samples (44.86%). Small-sized microplastics (53-300 μm) prevailed in all samples. Color delineation exhibited an abundance of transparent microplastics. Chemical characterization indicated the dominance of polypropylene (38%), followed by high-density polyethylene, low-density polyethylene, and polystyrene. The calculated PNEC value was 3,954 particles/m3, and the RQ was estimated to be 0.02073-0.04122 indicating negligible ecological risk to freshwater species in all the sampling sites.
摘要：
微塑料由于其长期普遍存在和持续存在而成为全球威胁。小尺寸的微塑料会加速它们在每个营养级的摄取，导致生物放大和生物积累，这引起了公众的关注。本研究是孤立的，量化和表征丰度，形状,尺寸,颜色,以及通过扫描电子显微镜和FTIR从Hirakud水库的水和沉积物中提取的微塑料的化学成分。使用物种敏感性分布（SSD）方法评估与微塑料相关的生态风险，以得出预测的无影响浓度（PNEC）值和风险商（RQ）。Hirakud水库地表水和沉积物中微塑料的丰度估计为82-89个颗粒/L和159-163个颗粒/kg，分别。纤维状微塑料占地表水（46.21％）和沉积物样品（44.86％）。小尺寸微塑料（53-300μm）在所有样品中占主导地位。颜色描绘显示出丰富的透明微塑料。化学表征表明聚丙烯占主导地位（38％），其次是高密度聚乙烯，低密度聚乙烯，和聚苯乙烯。计算出的PNEC值为3,954个颗粒/m3，RQ估计为0.02073-0.04122，表明所有采样点对淡水物种的生态风险可忽略不计。
