Department of Geography, Tokyo Metropolitan University, Tokyo, 1920397, Japan.
Department of Chemistry, National University of Mongolia, Ulaanbaatar, 210646, Mongolia.
Environ Sci Pollut Res Int. 2019 May;26(14):14059-14072. doi: 10.1007/s11356-019-04632-1. Epub 2019 Mar 9.
Plastic pollution in aquatic environments is one of the most fatal environmental issues in the world. Although the distribution of plastic debris in the sea and at coasts has been addressed, the transportation of plastics through a river system is unclear but important. The distribution of plastic debris in the Selenga River system is responsible for the environmental pollution of Lake Baikal. Twelve sampling sites along the river shore of the Selenga River system have been surveyed considering the industrial activity and population density. The number of plastics significantly correlates with the population density. The higher the number of plastics is, the smaller is the average size. The size fractions of foam and film plastics show a significant relationship, suggesting that the plastic debris fragmented on-site on the river shores. The most abundant plastic debris is polystyrene foam (PSF), which is usually used for construction and packaging. Plastic debris occurs due to insufficient plastic waste management. Its distribution is affected by seasonal changes of the water level and flow rate of tributaries. Furthermore, the fragmentation of plastic debris is related to temperature changes associated with freeze and thaw cycles, solar radiation, and mechanical abrasion. Smaller microplastics with microscopic sizes were detected in PSF debris. Based on micro-Fourier transform infrared spectroscopy, these microplastics are polystyrene and polyethylene. This study proves that invisible and visible microplastics are transported together.
塑料污染是全球最致命的环境问题之一。尽管已经研究了海洋和海岸地区塑料碎片的分布情况，但塑料通过河流系统的迁移情况尚不清楚，但却很重要。色楞格河流域的塑料碎片分布导致了贝加尔湖的环境污染。考虑到工业活动和人口密度，在色楞格河流域的河岸沿线的 12 个采样点进行了调查。塑料的数量与人口密度呈显著正相关。塑料数量越多，平均尺寸越小。泡沫和薄膜塑料的粒径分数呈显著相关，表明塑料碎片在河岸现场发生了破碎。最丰富的塑料碎片是聚苯乙烯泡沫（PSF），通常用于建筑和包装。由于塑料废物管理不足，导致了塑料碎片的产生。其分布受支流水位和流量季节性变化的影响。此外，与冻融循环、太阳辐射和机械磨损相关的温度变化导致了塑料碎片的破碎。在 PSF 碎片中检测到了具有微观尺寸的更小的微塑料。基于微观傅里叶变换红外光谱，这些微塑料是聚苯乙烯和聚乙烯。本研究证明了不可见和可见的微塑料是一起迁移的。
