College of Earth and Environmental Sciences, University of the Punjab, Lahore, Pakistan.
State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), School of Environment, Tsinghua University, Beijing, 100084, China.
Environ Sci Pollut Res Int. 2020 May;27(14):16718-16730. doi: 10.1007/s11356-020-08114-7. Epub 2020 Mar 4.
Plastics are widely considered to be a major threat particularly in the urban areas owing to extensive use of plastic products. The current study is the first investigation to highlight the microplastics (MPs) pollution from the freshwater (Ravi River) located in the predominant urban center, i.e., Lahore, Pakistan. The concentration profile was quantified from surface water (n = 19) and sediments (n = 19) collected from different drains and canals of predominant freshwater resources in Lahore, Pakistan. The highest content of MPs was observed in the sullage carrier with mean concentration of 16,150 ± 80 MPs/m and 40,536 ± 202 MPs/m in the water and sediments respectively. The lowest level was detected in the link canals with mean concentration of 190 ± 141 MPs/m in the water and 683 ± 479 MPs/m in the sediments. The proportion of large size MPs (300 μm-5 mm) was maximum in the upstream section of Ravi river, whereas fine size MPs (50-150 μm) were dominant in the downstream section. In terms of shapes, the fragments were predominant with a relative abundance of 56.1% and 83.1% followed by fibers with a relative abundance of 38.6% and 11.8% in the water and sediments respectively. The chemical composition analysis showed that most of the fibers, fragments, and beads were polyethylene while the sheets were composed of polypropylene. Nevertheless, the foams isolated from the samples were composed of polystyrene. Within 24 h, about 2.4 ± 2.4 billion microplastic pieces were estimated to be transported from a single water channel into the river. The highest discharge of MPs was estimated from the sullage carrier with about 7 billion pieces/day.
塑料被广泛认为是一个主要的威胁，尤其是在城市地区，由于广泛使用塑料制品。本研究首次调查了位于巴基斯坦主要城市中心拉合尔的淡水（拉维河）中的微塑料（MPs）污染。从拉合尔不同排水渠和运河的地表水（n=19）和沉积物（n=19）中定量了浓度分布。在污水输送渠中观察到 MPs 的含量最高，其水中和沉积物中的平均浓度分别为 16150±80 MPs/m 和 40536±202 MPs/m。在连接运河中检测到的浓度最低，水中和沉积物中的平均浓度分别为 190±141 MPs/m 和 683±479 MPs/m。大尺寸 MPs（300 μm-5 mm）的比例在上游拉维河河段最大，而小尺寸 MPs（50-150 μm）在下游河段占主导地位。就形状而言，碎片占主导地位，相对丰度为 56.1%和 83.1%，其次是纤维，相对丰度分别为 38.6%和 11.8%，分别存在于水中和沉积物中。化学成分分析表明，大多数纤维、碎片和珠子由聚乙烯组成，而薄片由聚丙烯组成。然而，从样品中分离出的泡沫由聚苯乙烯组成。在 24 小时内，估计有大约 24 亿个微塑料碎片从单个水道输送到河中。从污水输送渠中估计的 MPs 排放量最高，约为每天 70 亿个。
