Institute of Geography , University of Bern , Hallerstrasse 12 , 3012 Berne , Switzerland.
Environ Sci Technol. 2018 Mar 20;52(6):3591-3598. doi: 10.1021/acs.est.7b06003. Epub 2018 Mar 1.
Microplastics (MPs) are small (<5 mm diameter) but have clear implications for the environment. These artificial particles are found in and pose threats to aquatic systems worldwide. MPs have terrestrial sources, but their concentrations and fates in the terrestrial environment are poorly understood. While global plastic production continues to increase, so do the environmental concentrations and impacts of MPs. In this first study of MPs in floodplain soils, we developed a method for identifying, quantifying, and measuring the sizes of most commonly produced MPs in soil by FT-IR microscopy. For small MP (<1 mm) analysis, MP were separated by density separation and oxidation of organic matter. In this study we analyzed 29 floodplains in Swiss nature reserves associated with catchments covering 53% of Switzerland. We found evidence that 90% of Swiss floodplain soils contain MPs. The highest MP concentrations were associated with the concentration of mesoplastics (5 mm - 2.5 cm diameter), indicating plastic waste as source. Furthermore, MP concentration was correlated with the population of the catchment. The wide distribution of MPs, their presence in remote unsettled high mountain areas, decoupling of MEP and MP compositions, and the dominance of MPs by small (<500 μm diameter) particles, indicate that MPs enter soils via diffuse aeolian transport.
微塑料（MPs）是指直径小于 5 毫米的小颗粒，但对环境有明显影响。这些人工颗粒存在于世界各地的水生系统中，并构成威胁。MPs 有陆地来源，但它们在陆地环境中的浓度和命运还了解甚少。随着全球塑料产量持续增加，MPs 的环境浓度和影响也在增加。在这项对洪泛区土壤中 MPs 的首次研究中，我们开发了一种通过傅里叶变换红外显微镜识别、定量和测量土壤中最常见的 MPs 大小的方法。对于小 MPs(<1 毫米)的分析，通过密度分离和有机物氧化来分离 MPs。在这项研究中，我们分析了瑞士自然保护区的 29 个洪泛区，这些洪泛区与覆盖瑞士 53%的流域有关。我们有证据表明，90%的瑞士洪泛区土壤含有 MPs。 MPs 浓度最高的地区与中 MPs（5 毫米-2.5 厘米直径）的浓度有关，表明塑料垃圾是其来源。此外，MP 浓度与流域的人口有关。 MPs 的广泛分布、在偏远未开垦的高山地区的存在、MEP 和 MP 组成的解耦以及由小(<500 微米直径)颗粒主导的 MPs，表明 MPs 通过弥散风输运进入土壤。
