Pay Attention to Research on Microplastic Pollution in Soil for Prevention of Ecological and Food Chain Risks

Marine microplastic pollution considered as an emerging environmental problem has been highly recognized worldwide. Comparatively, no such attention has been paid on soil microplastic pollution especially in agricultural land. This paper reviews research progress in sources, accumulation, degradation, transport, and potential risks in eco-environment and food chain, and suggests relevant countermeasures in governance and research. It is also pointed out that microplastics may enter into the agricultural soils through various sources and pathways, including agricultural film breaking, organic manure application, water irrigation, sewage sludge utilization, atmospheric deposition, and surface runoff, and then accumulate in surface layer, while animal and possibly edible plants grown in soils, likely posing risks on ecosystem and food chain. However, the accumulation, forms, movement, degradation of microplastics in soil-animal-plant systems and their risks on eco-environment, food chain, and human health have been poorly understood. It is also lack of study and awareness in good measures for prevention, control, and remediation of microplastic pollution in soil. Therefore, the study also put forward to attach importance of research in microplastic pollution and treatment in soil for prevention of ecological and food chain risks. It is suggested that China should speed up the establishment of analytical methodology for soil microplastic study and accelerate deployment strategy for systematic research in soil microplastic pollution and treatment, aiming at understanding accumulation, release, transformation, and their eco-environmental effects of microplastics and corresponding additives and metabolites in soil, evaluating potential impacts of microplastics and its attached pollutants on risks to soil biotas, ecosystem, and food chain, and constructing technology systems for source control and remediation of microplastic pollution in soil. Thus, both scientific basis and technological support can be well provided for governance and treatment of microplastics in soil and terrestrial ecosystems in China.