土壤环境中微塑料的研究进展

A review of microplastics in the soil environment

微塑料是一类广泛存在于环境中的塑料颗粒,近年来,微塑料对环境的污染引起了国内外学者的广泛关注。关于微塑料对水环境造成的负面影响有较多报道,但微塑料在陆地环境特别是土壤中的存在和影响的系统性研究鲜有报道。本文从土壤微塑料的来源和分布、分析方法、对生态系统的影响、生态环境效应及管控措施等方面进行了系统综述,并针对今后土壤微塑料的研究提出了相关对策。主要包括以下几个方面:1)土壤微塑料的主要来源包括农用塑料薄膜残留、污泥的土地利用、有机肥施用、地表径流、污水灌溉和大气沉降;2)总结了土壤中微塑料的分离、提取、鉴定及分析方法的优缺点,但目前仍没有标准化的检测和定量技术;3)微塑料会影响土壤的结构和理化性质,对植物和动物的生长造成威胁,并改变微生物群落的多样性;4)微塑料表面可附着污染物,对环境造成物理和化学污染,可释放内源性有毒物质,并导致复合污染效应;5)微塑料污染的防控措施主要包括3个方面:研发生物降解塑料产品、从源头控制微塑料的输入以及加强世界各国合作。提出今后微塑料的研究应建立统一的定量分析标准方法,发展更准确的可追溯分析技术,加强对土壤中微塑料污染的科学研究。本研究不仅有助于了解微塑料在土壤中的环境行为,为进一步探索土壤微塑料提供思路,而且可为土壤中微塑料的生态风险评估及污染防治提供理论依据和参考。

Microplastics are plastic particles widely distributed in the environment.In recent years,environmental pollution caused by microplastics has attracted widespread attention.Many studies have reported the negative effects of microplastics on the aquatic environment,but the impact of microplastics on the terrestrial environment,especially on soils,has not been extensively investigated.This study systematically reviewed the recent researches on the sources,distribution,pollution characteristics,analysis methods,ecological effects,environmental effects,and control measures of soil microplastics,and proposed relevant countermeasures for research and governance.This review showed that 1)the sources of soil microplastics included residues of agricultural plastic film,land use of sludge,organic fertilizer application,surface runoff,sewage irrigation,and atmospheric deposition.2)The methods of separation,extraction,identification,and their advantages and disadvantages for determining soil microplastics were summarized,but standardized detection and quantitative technologies were lacking.3)Microplastics could affect the soil structure and physical and chemical properties,threatened the growth of plants and animals,and changed the diversity of microbial communities.4)Microplastics could adhere to pollutants on the surface,causing physical and chemical environmental pollution,endogenous toxic substances releasing,and inducing compound pollution.5)The prevention and control measures of microplastic pollution were mainly focused on three factors:research and development of biodegradable plastic products,input control of microplastics from the source,and strengthening international cooperation.This study also proposed three areas in need of further development:a standard unified quantitative analysis method,more accurate traceability analysis technology,and better scientific research on microplastic pollution in the soil.The results presented here provided a better understanding of the environmental behavior of microplastics in the soil and proposed ideas for further exploration.This review also provided a theoretical basis and reference for the ecological risk assessment of soil microplastics and prevention of pollution caused by them.