School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China.
School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China.
Sci Total Environ. 2018 Nov 15;642:12-20. doi: 10.1016/j.scitotenv.2018.06.004. Epub 2018 Jun 9.
Plastic particle accumulation in arable soils is a growing contaminant of concern with unknown consequences for soil productivity and quality. This study aimed to investigate abundance and distribution of plastic particles among soil aggregate fractions in four cropped areas and an established riparian forest buffer zone at Dian Lake, southwestern China. Plastic particles (10-0.05 mm) from fifty soil samples were extracted and then sorted by size, counted, and categorized. Plastic particles were found in all soil samples. The concentration of plastic particles ranges from 7100 to 42,960 particles kg (mean 18,760 particles kg). 95% of the sampled plastic particles are in the microplastic size (1-0.05 mm) range. The predominant form is plastic fibers, making up on average 92% of each sample followed by fragments and films that contributed with to 8%. Results of this study also show that 72% of plastic particles are associated with soil aggregates, and 28% of plastic particles are dispersed. The abundance of aggregate-associated plastic fibers is significantly greater in the micro-aggregate than that in the macro-aggregate, whereas the less concentrations of plastic films and fragments are found in the micro-aggregate. Compared to the adjacent vegetable soil, the less concentration of plastic particles in the buffer soil implicates that application of soil amendments and irrigation with wastewater must be controlled to reduce accumulation of microplastics in agricultural soils. While the implications of microplastic on ecological and human health are poorly understood, the staggering number of microplastic in agricultural soils should be continually concerned in the future.
农田土壤中塑料颗粒的积累是一种日益受到关注的污染物，其对土壤生产力和质量的未知影响令人担忧。本研究旨在调查中国西南部滇池四个种植区和一个已建立的河岸森林缓冲带中土壤团聚体各部分中塑料颗粒的丰度和分布。从五十个土壤样本中提取了（10-0.05mm）的塑料颗粒，然后按大小进行分类、计数和分类。所有土壤样本中均发现了塑料颗粒。塑料颗粒的浓度范围从 7100 到 42960 个颗粒 kg（平均值为 18760 个颗粒 kg）。抽样的塑料颗粒中 95%处于微塑料尺寸（1-0.05mm）范围内。主要形式是塑料纤维，平均占每个样本的 92%，其次是碎片和薄膜，分别占 8%。本研究的结果还表明，72%的塑料颗粒与土壤团聚体有关，28%的塑料颗粒呈分散状态。微团聚体中与团聚体相关的塑料纤维的丰度明显大于大团聚体中的丰度，而微团聚体中塑料薄膜和碎片的浓度较低。与相邻的菜地土壤相比，缓冲土壤中塑料颗粒的浓度较低，这表明必须控制土壤改良剂的应用和污水灌溉，以减少农业土壤中微塑料的积累。虽然微塑料对生态和人类健康的影响知之甚少，但农业土壤中微塑料的数量之多令人震惊，未来应持续关注。
