Research Center for Ecology and Environment of Qinghai-Tibetan Plateau, Tibet University, Lhasa, 850000, China.
College of Science, Tibet University, Lhasa, 850000, China.
Environ Monit Assess. 2023 Mar 1;195(3):433. doi: 10.1007/s10661-023-11040-z.
Microplastics (MPs) are ubiquitous in the aquatic environment and have received widespread attention worldwide as emerging pollutants. Urbanization and anthropogenic activities are the main sources of MPs in rivers; however, the MPs in plateau rivers with less human activities are not well understood. In this study, the pollution of MPs in the surface water and shore sediment of the Lhasa River from the Qinghai-Tibet Plateau was investigated, and a risk assessment was conducted. The abundance of MPs in the surface water and shore sediment of Lhasa River were 0.63 n/L and 0.37 n/g, respectively. MPs in surface water were mainly dominated by films (43.23%) and fibers (31.12%) in shape, transparent (54.25%) in color, and 0-0.5 mm (75.83%) in size, while MPs in the shore sediment were mainly fibers (43.69%) and fragments (36.53%), transparent (71.91%), and 0-0.5 mm (60.18%). PP and PE were the predominant polymer types, accounting for 44.55% and 30.79% respectively in the surface water and 32.51% and 36.01% respectively in the shore sediment. More notably, the polymer pollution index (H) of MPs in the Lhasa River was at hazard level III due to the high risk caused by PVC, but the pollution load index (PLI) was low at hazard level I. This study reveals that the remote river in the Qinghai-Tibet Plateau are polluted by MPs, and their potential risks to the vulnerable ecosystem deserve attention.
微塑料（MPs）广泛存在于水生环境中，作为新兴污染物已受到全球广泛关注。城市化和人为活动是河流中 MPs 的主要来源；然而，人类活动较少的高原河流中的 MPs 情况还不太清楚。本研究调查了青藏高原拉萨河地表水和岸边沉积物中 MPs 的污染情况，并进行了风险评估。拉萨河地表水和岸边沉积物中 MPs 的丰度分别为 0.63 n/L 和 0.37 n/g。地表水中的 MPs 主要以薄膜（43.23%）和纤维（31.12%）为主，形状为透明（54.25%），尺寸为 0-0.5 mm（75.83%）；而岸边沉积物中的 MPs 主要为纤维（43.69%）和碎片（36.53%），透明（71.91%），尺寸为 0-0.5 mm（60.18%）。PP 和 PE 是主要的聚合物类型，分别占地表水的 44.55%和 30.79%，占岸边沉积物的 32.51%和 36.01%。更值得注意的是，由于 PVC 造成的高风险，拉萨河 MPs 的聚合物污染指数（H）处于危险水平 III，但污染负荷指数（PLI）处于低危险水平 I。本研究表明，青藏高原偏远河流受到 MPs 的污染，它们对脆弱生态系统的潜在风险值得关注。
