Due to the massive production and consumption in modern society, plastic products are delivered into the aquatic environment. The plastic waste in the aquatic environment would break down into numerous small plastic fragments with a size <5 mm, namely microplastics. As emerging environmental contaminants, microplastics have been received global attention from both scientific and public communities. Nowadays, most of the available literature concentrates mainly on the microplastics pollution in the marine environment. Due to the frequent contact with people, the microplastics pollution in the terrestrial freshwater environment should be considered more carefully. In order to get a thorough understanding of the microplastics pollution in the freshwater environment and strengthen the risk management, the occurrence, source and ecotoxicological effect of microplastics in the freshwater environment were reviewed based on the previous studies in recent years. The occurrences of microplastics have been reported in water, sediments and organisms, indicating that the microplastics pollution may be distributed worldwide in the freshwater environment. Moreover, it seems that the microplastics pollution in China is more significant than that in other countries. To date, the sources of microplastics in the freshwater environment are still not very well characterized. The main direct sources of microplastics may include effluents of wastewater treatment plants, degradation of plastic waste in the aquatic environment, and terrestrial input by soil erosion or runoff, while personal care products, synthetic textiles, industrial materials, and mismanaged plastic waste from urban, agricultural, touristic and industrial areas are considered the ultimate origins of microplastics in the freshwater environment. Microplastics can trigger physical effects and biochemical perturbations in freshwater organisms. Furthermore, it may lead to combined pollution with other contaminants, eventually inducing interactive effects on freshwater organisms. Collectively, there is an urgent need to investigate the microplastics pollution in the freshwater environment. In the future, the influence of environmental factors on the microplastics pollution characteristic, the analysis of the sources of microplastics, and the interactive effects between microplastics and other contaminants on freshwater organisms should be further studied. This paper would provide a theoretical reference for the study concerning the microplastics pollution and the ecological risk in freshwater environments.%塑料制品在当今社会中被大量生产和使用,导致其不断进入水环境.环境中的塑料垃圾会进一步分解为很多粒径小于5 mm的塑料残片,即微塑料.微塑料作为一类新型污染物,已受到国内外学者和公众的广泛关注.然而,现阶段有关微塑料污染的研究主要集中在海洋环境,而内陆淡水环境与人类接触频繁,其微塑料污染应受到更多重视.为全面了解淡水环境中微塑料污染现状,加强对微塑料污染的风险监控,文章总结了近些年的相关研究,综述了淡水环境中微塑料的赋存、来源和生态毒理效应.有关研究表明,微塑料污染可能在全世界淡水环境中普遍存在,其在淡水水体、沉积物和淡水生物中均有赋存;而中国内陆淡水环境中微塑料的污染可能尤为严重.淡水环境中微塑料的来源尚不明确,主要直接来源可能包括污水处理厂的尾水排放、水环境中塑料垃圾的风化降解以及水土流失或地表径流形成的陆源输入;而初始源头可能包括了个人护理品、合成纺织品、工业原料以及城镇、农业、旅游、工业区塑料垃圾的不当处置.另外,微塑料会对淡水生物造成物理性损伤和生化水平胁迫,并有可能与其他污染物形成复合污染,对淡水生物产生交互效应.因此,对淡水环境中微塑料污染的深入研究已刻不容缓.今后可在环境因素对微塑料污染特征的影响、微塑料污染的源解析、微塑料与污染物的生态交互效应这三方面加强研究.文章可为淡水环境中微塑料的污染和生态风险研究提供理论参考.
展开▼
