闸坝河流微塑料特征及污染风险评估

Microplastic Characteristics and Risk Assessment in Multigate Dam-type River

微塑料污染对我国淡水河流造成了严重的生态威胁,大量闸坝的建设使该污染复杂化.以沙颍河流域10个闸坝为对象,调查水库及上游河道的地表水和沉积物中的微塑料丰度和组成,并利用物种敏感性分布和污染负荷指数进行风险评估.结果表明,沙颍河面临自上游而下较为严重的微塑料污染.闸坝建设对河流中的微塑料分布影响不显著,微塑料的分布可能受到多种其他环境因素的影响.河流沉积物是地表水中微塑料的汇,但水体中微塑料带来的生态风险更大.两种评估方式的对比表明,物种敏感性分布评估相较污染负荷指数更能体现生物对污染物的积累和摄食行为.

Microplastics pose a serious ecological threat to rivers in China,and the construction of a large number of dams has complicated this problem.Ten dams of the Shaying River were chosen to investigate the abundance and composition of microplastics in surface water and sediments of the reservoir and upstream river.Ecological risk was evaluated using species sensitive distribution(SSD)and pollution load index(PLI).The results showed that the Shaying River was exposed to a severe risk of microplastics from upstream to downstream.The construction of dams did not significantly affect the distribution of microplastics in the river.River sediments became a sink for microplastics in the surface water;however,the ecological risk posed by microplastics in the surface water was greater,and the comparison of the two assessment methods showed that the species sensitivity distribution assessment better reflected the accumulation and feeding behavior of organisms to pollutants compared to the pollution load index.