中国淡水环境中微塑料的空间异质性及其影响因素分析OA

In this study,we systematically reviewed the abundance,characteristics,and sources of micro-plastic pollution in the freshwater environment of China.The study was based on relevant literature using the keywords"China,""microplastic,""river,""lake,""reservoir,"and"estuary"in two major English search engines(Web of Science and ScienceDirect)and from the China National Knowledge Infrastruc-ture(CNKI)database.A total of 191 articles met the screening criteria,encompassing four major freshwa-ter environments:rivers,lakes,reservoirs and estuaries.Studies included both surface water and sediment and were primarily concentrated in the Yangtze,Pearl,and Yellow River basins.Results show that micro-plastic pollution is widespread in the freshwater environment of China and there is significant spatial het-erogeneity in abundance.The maximum and minimum values of microplastic abundance in surface waters differed by 6 orders of magnitude and by 3 orders in sediments.Overall,the distribution was character-ized by high levels in the eastern coastal areas and low levels in the central regions,and the microplastic content in rivers and estuaries was usually higher than that in lakes and reservoirs.The characteristics of microplastics in different river basins were relatively consistent:the primary polymer types were polypro-pylene(PP)and polyethylene(PE);the primary shapes were fibers and fragments;the colors were trans-parent,white,black and other;and there are certain differences by region.The presence of microplastics is closely related to human activities and surface water type,and there is significant seasonal variation.Further,inconsistencies in sample collection,experimental methods,and classification methods make it difficult to compare different assessments of microplastic pollution.In the future,it will be necessary to expand the scope of microplastic pollution surveys,strengthen long-term longitudinal monitoring,study the sources,movement and sinks of microplastics,enhance detection capabilities,and develop standard-ized methods for collecting and classifying microplastics.