Department of Environmental Science and Engineering, Faculty of Natural Resources, University College of Agriculture & Natural Resources, University of Tehran, P.O. Box 4314, Karaj, 31587-77878, Iran.
Department of Earth Sciences, School of Science, Shiraz University, Shiraz, 71454, Iran.
Environ Sci Pollut Res Int. 2024 Sep;31(42):54815-54831. doi: 10.1007/s11356-024-34847-w. Epub 2024 Aug 31.
Microplastic pollution has raised significant concerns among scientific communities and society in recent years due to its increase and lesser-known effects on the environment. To improve the knowledge of microplastic pollution in freshwater, we investigated microplastics in Anzali Wetland, a Ramsar site in northern Iran, as well as its nine main entering rivers. The extracted microplastics were characterized via visual identification, SEM-EDX, and μ-Raman methods. Microplastics (size range: 50-5000 μm) were found in all water and sediment samples with concentration of fibrous particles as well as polypropylene and polyethylene polymers. The mean concentration of microplastics in bottom sediment and surface water samples of the wetland was 301 ± 222 particles∙kg d.w. and 235 ± 115 particles∙m (0.23 particles∙L), respectively. The microplastic concentration in the central and eastern parts of the wetland was higher than in other areas; however, the mean concentrations revealed homogeneity across the wetland area. Water properties (dissolved oxygen, pH, temperature, electrical conductivity, and salinity in water) did not affect the concentration of microplastic particles, though correlational analysis revealed a strong positive association between microplastic quantity and turbidity. There was a significant positive relationship between microplastic concentration and the percentage of clay in sediment samples. The quantity of microplastics in river water was higher than in wetland water, but the difference between the results was not significant. However, the quantity of microplastics in the river's littoral sediment was higher than in the bottom sediment of the wetland where the difference between the results was significant. Microplastic ecological risk assessment showed high potential ecological risk. The findings underscore the importance of effective management strategies and the implementation of policies to mitigate the negative impact of MP pollution on ecosystems and human health.
近年来，由于微塑料在环境中的增加及其鲜为人知的影响，微塑料污染引起了科学界和社会的高度关注。为了提高对淡水微塑料污染的认识，我们调查了伊朗北部拉姆萨尔湿地的微塑料，以及其 9 条主要入河。通过肉眼观察、SEM-EDX 和 μ-Raman 等方法对提取的微塑料进行了特征描述。在所有水样和沉积物样本中都发现了微塑料（尺寸范围：50-5000μm），浓度较高的是纤维颗粒以及聚丙烯和聚乙烯聚合物。湿地底泥和表层水中微塑料的平均浓度分别为 301±222 个∙kg d.w.和 235±115 个∙m（0.23 个∙L）。湿地中部和东部的微塑料浓度高于其他地区，但平均浓度在湿地范围内表现出均匀性。水的性质（溶解氧、pH 值、温度、电导率和水的盐度）并没有影响微塑料颗粒的浓度，尽管相关分析显示微塑料数量与浊度之间存在强烈的正相关关系。微塑料浓度与沉积物样品中粘土百分比之间存在显著的正相关关系。河流水中的微塑料数量高于湿地水中，但结果之间的差异并不显著。然而，河流滨岸沉积物中的微塑料数量高于湿地底泥中的微塑料数量，结果之间存在显著差异。微塑料生态风险评估显示出高潜在生态风险。这些发现强调了采取有效管理策略和实施政策的重要性，以减轻微塑料污染对生态系统和人类健康的负面影响。
