厦门湾沙滩沉积物微塑料污染特征

Pollution Characteristics of Microplastics in Sediments of Xiamen Bay Beach

微塑料(MPs)广泛存在于各种环境介质中,目前已经成为全球性环境问题.为了解海湾沙滩沉积物中微塑料的污染特征,揭示微塑料沉积规律及其影响因素,在厦门湾选择了5个典型沙滩,根据潮汐变化,同时在高潮线、中潮线和低潮线分层采集了0~10、 10~20和20~30 cm的沉积物柱状样品,研究了沙滩沉积物中微塑料水平与垂直分布特征.结果表明,厦门湾沙滩45个沉积物样品中均检出微塑料,微塑料丰度范围为39~260 n·kg^(-1),平均丰度为(114±26)n·kg^(-1);微塑料形状主要为纤维状、碎片状、颗粒状和泡沫状,其中纤维状占比最大;主要成分为聚对苯二甲酸乙二醇酯(PET)、赛璐芬(cellophane)和聚乙烯(PE);微塑料的颜色包括透明、蓝色、黄色、黑色和白色等.从统计结果可以看出,微塑料的平均丰度因沙滩位置、潮间带位置和采样深度的不同呈一定的规律,并且波浪、潮汐、岸线形状、风、游客数量和海漂垃圾清洁等自然和人为多种因素均影响沙滩微塑料的丰度和分布.研究成果有助于了解沙滩沉积物中微塑料的污染特征及来源,为微塑料的陆海传输提供依据,对海漂垃圾及岸滩垃圾收集提供数据支撑.

Microplastics widely exist in various environmental media and have become a global environmental problem. To investigate the pollution characteristics, deposition patterns, and influencing factors of microplastics in the sediments of bay beach, five typical beaches were selected in Xiamen Bay. According to the tidal variation, 0-10 cm, 10-20 cm, and 20-30 cm sediment column samples were collected in layers at the high tide line, middle tide line, and low tide line at the same time, and the characteristics of the horizontal and vertical distribution of microplastics in the beach sediments were studied. The results showed that the abundance of microplastics in 45 sediment samples in Xiamen Bay beach ranged from 39 to 260 n·kg^(-1), with an average abundance of(114±26) n·kg^(-1). The shapes of microplastics were mainly fibers, fragments, granules, and foams, with fibers making up the largest proportion. The main components were polyethylene terephthalate(PET), cellophane, and polyethylene(PE). The colors of microplastics included transparent, yellow, blue, black, white, etc. The average abundance of microplastics showed a certain pattern depending on the beach location, intertidal zone, and sampling depth. Moreover, the abundance and distribution of microplastics on the beach were affected by various natural and human factors such as waves, tides, shoreline shape, the number of tourists, and the cleaning of marine floating debris. These results aid the understanding of the distribution characteristics and sources of microplastics in beach sediments, provide a basis for the transport of microplastics from land to sea, and provide data support for the collection of sea floating garbage and shoreline garbage.