Pollution levels and spatial distributions of polychlorinated biphenyls in sediments of Yangtze Estuary during water impoundment of Three Gorges Reservoir
Abstract：The surface sediment and core sediment samples taken from the Yangtze Estuary during the water impoundment of the Three Gorges Reservoir were analyzed to reveal the pollution levels and spatial distributions of polychlorinated biphenyls (PCBs). The PCB levels of the Yangtze Estuary were relatively low compared to other industrial/urban coastal environments worldwide. Generally, the samples taken in November were less polluted by PCBs than those taken in August and February because of the changes of PCB input and the water impoundment of the Three Gorges Reservoir. Samples collected in the north branch showed higher PCB concentrations. In the adjacent sea area, PCB values along the –20m isobath were higher than those along the –10m isobath due to the “marginal filter” phenomenon formed by different water currents. The effects of the physicochemical characteristics (TOC and grain size) of surface sediments on the distributions of PCBs were also investigated. Masked by various other factors, the TOC contents and sediment grain sizes did not exhibit a strong influence on the distributions of PCBs. Analysis of the PCB congener distribution patterns revealed the predominant proportion of light PCBs with 2~3chlorines. According to the principal component analysis (PCA) of source contributions, the PCB sources of the north and south branch were quite different, and the PCB sources have changed from the past.
高硕晗, 陈静, 司政, 沈珍瑶. 三峡水库蓄水期长江口多氯联苯的污染特征[J]. 中国环境科学, 2013, 33(11): 2062-2068.
GAO Shuo-Han, CHEN Jing, SI Zheng, SHEN Zhen-Yao. Pollution levels and spatial distributions of polychlorinated biphenyls in sediments of Yangtze Estuary during water impoundment of Three Gorges Reservoir. CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(11): 2062-2068.
