Padha Shaveta, Kumar Rakesh, Sharma Yogesh, Dhar Anjali
Department of Zoology, Central University of Jammu, Jammu & Kashmir 181143, India.
Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA.
J Contam Hydrol. 2025 Feb;269:104490. doi: 10.1016/j.jconhyd.2024.104490. Epub 2024 Dec 20.
Microplastics (MPs) are ubiquitous and are increasing globally, but there is limited information available on their presence in freshwater ecosystems. This research work aims to investigate the abundance, sinking behavior, and risk assessment of MPs in the freshwater River Basantar, Jammu & Kashmir, India. Microplastic abundance in sediments was recorded in the range of 1-6 items g, with a mean abundance of 3 ± 1.594 item g, whereas MPs in surface water ranged from 200 to 850 items L with a mean abundance of 530 ± 218.4 items L among 12 sites for sediments and 10 sites for surface water. Besides, the sinking behavior of MPs was analyzed through portioning coefficients (K) at sediments-surface water interface, which ranges from 0.71 to 2.50 L Kg for River Basantar. The most common shapes identified were fragments, fibres, and films, followed by pellets, foams, and lines. ATR-FTIR polymeric characterization reported polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride, and thus, polymeric risk assessment analysis was also evaluated and normally distributed in the River Basantar. Polymer Hazard Index was calculated across all the sites which observed to be polluted under risk categories "III" and "IV" for both the sediments and surface water samples. Pollution Load Index (PLI) calculated across all the sites was >1 depicting all the sites for both sediments and surface water sampling to be polluted. Pollution Risk Index was assessed and majority of surface water and sediment samples were observed to be under "Very high" risk category. The study, using principal component analysis and heatmap analysis, found that MPs are primarily a result of urbanization and anthropogenic actions, like industrial discharges, household wastes, and agricultural runoffs. This study highlights the significance of more investigation and coordinated efforts to solve the worldwide problem of plastic pollution in freshwater environments. Results data provide insight into the current state of MP contamination and will help government authorities implement strict rules and perform management interventions to reduce and monitor pollution levels in River Basantar. Future studies on the partitioning of MPs in sediments and surface water must be focused on aggregation, biofouling, plastic density & size, salinity, and flow behaviors to understand transport and deposition in rivers.
微塑料在全球范围内普遍存在且数量不断增加，但关于它们在淡水生态系统中的存在情况，现有信息有限。这项研究工作旨在调查印度查谟和克什米尔地区巴萨楠塔尔淡水河中的微塑料丰度、沉降行为及风险评估。沉积物中的微塑料丰度记录在每克1至6个颗粒的范围内，平均丰度为每克3±1.594个颗粒，而地表水中的微塑料丰度在每升200至850个颗粒之间，在沉积物的12个采样点和地表水的10个采样点中，平均丰度为每升530±218.4个颗粒。此外，通过沉积物 - 地表水界面的分配系数（K）分析了微塑料的沉降行为，巴萨楠塔尔河的分配系数范围为0.71至2.50升/千克。识别出的最常见形状为碎片、纤维和薄膜，其次是颗粒、泡沫和线状。衰减全反射傅里叶变换红外光谱（ATR - FTIR）聚合物表征显示存在聚乙烯、聚丙烯、聚苯乙烯、聚对苯二甲酸乙二酯和聚氯乙烯，因此，还对聚合物风险评估进行了分析，且其在巴萨楠塔尔河中呈正态分布。计算了所有采样点的聚合物危害指数，沉积物和地表水样本在风险类别“III”和“IV”下均被观察到受到污染。计算得出的所有采样点的污染负荷指数（PLI）>1，表明沉积物和地表水采样的所有地点均受到污染。评估了污染风险指数，观察到大多数地表水和沉积物样本处于“极高”风险类别。该研究通过主成分分析和热图分析发现，微塑料主要是城市化和人为活动的结果，如工业排放、家庭废物和农业径流。这项研究强调了进行更多调查和协同努力以解决淡水环境中全球塑料污染问题的重要性。结果数据提供了对微塑料污染现状的洞察，并将帮助政府当局实施严格规定并进行管理干预，以减少和监测巴萨楠塔尔河的污染水平。未来关于微塑料在沉积物和地表水之间分配的研究必须关注聚集、生物污损、塑料密度和尺寸、盐度及流动行为，以了解其在河流中的运输和沉积情况。
