Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology, H-12 Sector, Islamabad, Pakistan.
Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology, H-12 Sector, Islamabad, Pakistan.
Chemosphere. 2022 Dec;308(Pt 1):136111. doi: 10.1016/j.chemosphere.2022.136111. Epub 2022 Aug 19.
Occurrence of microplastics (MPs) in freshwater environments, particularly reservoir and lakes, is an emerging concern. There are limited studies in Pakistan on microplastic pollution in the lacustrine environments and those that exist do not provide sufficient information on the spatial distribution of MPs in offshore surface water. The aims of this study were to determine microplastic abundance in Rawal Lake, Pakistan and to ascertain if sampling methodology influences microplastic counts. Surface water samples were collected from 10 sites; 5 tributaries, 2 human settlement and 3 fishing and boating areas using two different sampling techniques: 100 μm mesh trawl and 20 L sample through a 45 μm mesh sieve. A significant difference was observed in the abundance of MPs across two methods with the sieve method yielding 2.8 ± 1.44 particles/L and trawl yielding 0.025 ± 0.024 particles/L. Tributaries and boating/fishing area had higher microplastic abundance than the residential area regardless of sampling method. Filaments were the dominant shape of MPs in both type of samples followed by fragments in trawl samples and films in sieved samples. Microbeads were only detected in trawl samples. MPs within size range 0.1-0.9 mm were mostly fragments (82%). MPs were diverse in colors with white/transparent and black MPs common. Polypropylene was the main type of microplastic in Rawal Lake (40-74%). Scanning Electron Microscopy (SEM) of MPs showed cracks, roughness and striations on the particles. Energy Dispersive Spectroscopy (EDS) detected heavy metals (Fe, Cu, Ni, Pb, Zn, Co and Cr) in MPs. Findings suggest that microplastic pollution in Rawal Lake may pose great risk to aquatic and human life through leaching of inherent/adsorbed heavy metals and therefore requires future investigation.
在淡水环境中，特别是在水库和湖泊中，微塑料（MPs）的出现是一个令人关注的新兴问题。在巴基斯坦，有关湖泊环境中微塑料污染的研究有限，而且现有的研究没有提供关于近海地表水微塑料空间分布的充分信息。本研究的目的是确定巴基斯坦拉瓦尔湖的微塑料丰度，并确定采样方法是否会影响微塑料的计数。使用两种不同的采样技术，从 10 个地点（5 个支流、2 个人口聚居区和 3 个捕鱼和划船区）采集了地表水样本：100μm 网拖和通过 45μm 网筛的 20L 样品。两种方法之间的 MPs 丰度存在显著差异，筛法的结果为 2.8±1.44 个/L，拖网法的结果为 0.025±0.024 个/L。无论采样方法如何，支流和划船/捕鱼区的微塑料丰度都高于居民区。在两种类型的样本中，纤维都是 MPs 的主要形状，其次是拖网样本中的碎片和筛网样本中的薄膜。微珠仅在拖网样本中检测到。0.1-0.9mm 大小范围内的 MPs 主要是碎片（82%）。MPs 的颜色多种多样，白色/透明和黑色 MPs 很常见。聚丙烯是拉瓦尔湖中主要的微塑料类型（40-74%）。 MPs 的扫描电子显微镜（SEM）显示出颗粒上的裂缝、粗糙度和条纹。能量色散光谱（EDS）在 MPs 中检测到重金属（Fe、Cu、Ni、Pb、Zn、Co 和 Cr）。研究结果表明，拉瓦尔湖的微塑料污染可能通过固有/吸附重金属的浸出对水生和人类生命构成巨大风险，因此需要进一步调查。
