Environ Sci Technol. 2015 May 19;49(10):6070-6. doi: 10.1021/acs.est.5b00492.
Plastic debris is one of the most significant organic pollutants in the aquatic environment. Because of properties such as buoyancy and extreme durability, synthetic polymers are present in rivers, lakes, and oceans and accumulate in sediments all over the world. However, freshwater sediments have attracted less attention than the investigation of sediments in marine ecosystems. For this reason, river shore sediments of the rivers Rhine and Main in the Rhine-Main area in Germany were analyzed. The sample locations comprised shore sediment of a large European river (Rhine) and a river characterized by industrial influence (Main) in areas with varying population sizes as well as sites in proximity to nature reserves. All sediments analyzed contained microplastic particles (<5 mm) with mass fractions of up to 1 g kg⁻¹ or 4000 particles kg⁻¹. Analysis of the plastics by infrared spectroscopy showed a large abundance of polyethylene, polypropylene, and polystyrene, which covered more than 75% of all polymer types identified in the sediment. Short distance transport of plastic particles from the tributary to the main stream could be confirmed by the identification of pellets, which were separated from shore sediment samples of both rivers. This systematic study shows the emerging pollution of inland river sediments with microplastics and, as a consequence thereof, underlines the importance of rivers as vectors of transport of microplastics into the ocean.
塑料碎片是水生环境中最主要的有机污染物之一。由于具有浮力和极端耐用性等特性，合成聚合物存在于河流、湖泊和海洋中，并在世界各地的沉积物中积累。然而，与海洋生态系统沉积物的调查相比，人们对淡水沉积物的关注较少。出于这个原因，对德国莱茵-美因地区莱茵河和美因河的河流岸滩沉积物进行了分析。采样地点包括一条大型欧洲河流（莱茵河）和一条受工业影响的河流（美因河）的岸滩沉积物，这些河流所在地区的人口规模不同，以及靠近自然保护区的地点。所有分析的沉积物都含有微塑料颗粒（<5 毫米），质量分数高达 1 克/千克或 4000 个颗粒/千克。通过红外光谱对塑料进行分析表明，大量的聚乙烯、聚丙烯和聚苯乙烯，占沉积物中所有识别出的聚合物类型的 75%以上。从支流到干流的塑料颗粒短距离迁移可以通过识别从两条河流的岸滩沉积物中分离出来的小球来证实。这项系统研究显示了内陆河流沉积物中微塑料的新兴污染，因此强调了河流作为将微塑料输送到海洋的载体的重要性。
