State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
The key Laboratory of Water and Air Pollution Control of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510000, China.
Sci Total Environ. 2022 Nov 15;847:157461. doi: 10.1016/j.scitotenv.2022.157461. Epub 2022 Jul 19.
Microplastic pollution has become pervasive in aquatic ecosystems. They readily interact with aquatic biota, potentially subjecting them to ecological and health risks. Urban rivers are also affected by microplastics due to intense anthropogenic activity. Nevertheless, relatively little is known about the physiocochemistry or ecotoxicology of microplastics in urban rivers. The present study used laser direct infrared chemical imaging to investigate microplastic pollution in a highly urbanized river in Beijing, China. Surface water was sampled at five sites along the river in March and July, and the benthic snail Bellamya aeruginosa was also collected at each location in July. Thirteen and fifteen different polymers were detected and identified in the surface water sampled in March and July, respectively. Thirteen different polymers were found and isolated in the snails. Of these, polypropylene, polyamide and polyethylene predominated in the microplastic particles. Moreover, the average abundance of the microplastic was significantly higher in the surface water sampled in July (39.55 ± 4.78 particles L) than in March (22.00 ± 4.87 particles L) (p < 0.05). The average microplastic abundance of snails across all sites was 28.13 ± 4.18 particles, among which the Q2 site has significantly higher microplastic abundance than station Q3-Q5 (p < 0.05). Microplastic particles 10-100 μm in size predominated in both the surface water and the snails. By contrast, the proportions of microplastic particles 200-500 μm in size were substantially smaller. The measured microplastic pollution load and microplastic pollution risk indices in the surface water indicated that the current microplastic pollution level in the Qing River was moderate from upstream to downstream. Moreover, the potential adverse effects of microplastic particles on snails remain unclear. Further research is required to elucidate small-size microplastics' environmental fate and potential ecological risks in urban rivers.
微塑料污染已在水生生态系统中普遍存在。它们很容易与水生生物相互作用，使它们面临生态和健康风险。由于人类活动强烈，城市河流也受到微塑料的影响。然而，对于城市河流中微塑料的物理化学性质或生态毒理学，人们知之甚少。本研究使用激光直接红外化学成像技术研究了中国北京一条高度城市化河流中的微塑料污染。3 月和 7 月在河流的五个地点采集地表水，7 月在每个地点还采集了底栖蜗牛玛瑙贝。在 3 月和 7 月采集的地表水中分别检测到并鉴定了 13 种和 15 种不同的聚合物。在蜗牛中发现并分离出 13 种不同的聚合物。其中，聚丙烯、聚酰胺和聚乙烯在微塑料颗粒中占主导地位。此外，7 月采集的地表水中微塑料的平均丰度（39.55±4.78 个/L）明显高于 3 月（22.00±4.87 个/L）（p<0.05）。所有地点的蜗牛中微塑料的平均丰度为 28.13±4.18 个，其中 Q2 点的微塑料丰度明显高于 Q3-Q5 点（p<0.05）。微塑料颗粒的大小为 10-100μm 占主导地位，在地表水和蜗牛中均如此。相比之下，尺寸为 200-500μm 的微塑料颗粒的比例要小得多。地表水的测量微塑料污染负荷和微塑料污染风险指数表明，目前从上游到下游，清河流的微塑料污染水平处于中等水平。此外，微塑料颗粒对蜗牛的潜在不利影响仍不清楚。需要进一步研究来阐明城市河流中小尺寸微塑料的环境归宿和潜在生态风险。
