School of Geographical Sciences/Hebei Key Laboratory of Environmental Change and Ecological Construction/Hebei Technology Innovation Center for Remote Sensing Identification of Environmental Change, Hebei Normal University, Shijiazhuang Hebei, 050024, China.
School of Geographical Sciences/Hebei Key Laboratory of Environmental Change and Ecological Construction/Hebei Technology Innovation Center for Remote Sensing Identification of Environmental Change, Hebei Normal University, Shijiazhuang Hebei, 050024, China.
Environ Pollut. 2023 Jun 15;327:121615. doi: 10.1016/j.envpol.2023.121615. Epub 2023 Apr 11.
Soils of croplands especially where plastic film mulch is commonly applied, are normally contaminated by Microplastics (MPs). Microplastics can threaten air quality, food and water health, as well as human health by wind erosion processes. In this research, we investigated MPs collected in four wind erosion events at sampling heights between 0 and 60 cm in typical semiarid farmlands in northern China that employ plastic film mulch. Height distribution and enrichment heights of the MPs were measured. The results revealed that the average amounts of MPs for 0-20 cm, 20-40 cm and 40-60 cm sampling heights were 868.71 ± 249.21, 799.87 ± 271.25, 1102.54 ± 317.44 particles kg. The average enrichment ratios of MPs for the different heights were 0.89 ± 0.54, 0.85 ± 0.56, 1.15 ± 0.73. Height distribution of MPs was combined affected by shape (fiber and non-fiber) and size of MPs, wind speed and soil aggregate stability. The amount of fibers approximately <4 mm in size and non-fibers <2 mm in size increased with sampling height, while both shapes of larger MPs than these two sizes was almost independent of the sampling height. Enrichment ratios of microfibers were positively related to wind speed but negatively related to soil aggregate stability at each sampling height. The results revealed that although MPs have similar density to organic matter (OM), the MPs' amount and enrichment were independent of height but the OM content and enrichment ratios increased with height. These results suggested that more attention should be paid to the exploration of the influence of higher sampling heights (>60 cm) on the distribution of MPs in the future and the MPs characteristics for different sampling heights require carefully parameterization in detailed models of atmospheric MPs transport by wind erosion.
农田土壤，特别是普遍应用塑料薄膜覆盖的农田土壤，通常受到微塑料（MPs）的污染。微塑料通过风蚀过程会威胁空气质量、食物和水的健康以及人类健康。在这项研究中，我们调查了在中国北方典型半干旱农田中，在四个风蚀事件中收集到的 MPs，这些农田采用了塑料薄膜覆盖。测量了 MPs 的高度分布和富集高度。结果表明，0-20cm、20-40cm 和 40-60cm 采样高度的 MPs 平均含量分别为 868.71±249.21、799.87±271.25 和 1102.54±317.44 个颗粒 kg。不同高度的 MPs 平均富集比分别为 0.89±0.54、0.85±0.56 和 1.15±0.73。MPs 的高度分布受 MPs 的形状（纤维和非纤维）和大小、风速和土壤团聚体稳定性的综合影响。大小约 <4mm 的纤维和 <2mm 的非纤维数量随采样高度增加而增加，而大于这两个尺寸的两种形状的 MPs 几乎与采样高度无关。微纤维的富集比与风速呈正相关，但与每个采样高度的土壤团聚体稳定性呈负相关。结果表明，尽管 MPs 与有机质（OM）具有相似的密度，但 MPs 的数量和富集与高度无关，而 OM 含量和富集比随高度增加而增加。这些结果表明，未来应更加关注更高采样高度（>60cm）对 MPs 分布的影响，并在详细的风蚀大气 MPs 传输模型中，对不同采样高度的 MPs 特征进行仔细参数化。
