大辽河口及其毗邻区域表层沉积物中多环芳烃的分布及其风险评估

Distribution and risk assessment of polycyclic aromatic hydrocarbons in the surface sediments of Daliao River Estuary and its adjacent regions,China

本研究采用气相色谱-质谱联用法（GC-MS）检测了大辽河口及其毗邻区域（包括大辽河口毗邻的上游河道和近岸海域）表层沉积物中多环芳烃（PAHs）的污染水平,并对其来源和生态风险进行评估。结果发现沉积物中多环芳烃总浓度（ΣPAHs）的范围是365×10^-9~11589×10^-9g/g干重,平均值为3700×10^-9g/g干重,总体为重度污染水平,与历史数据相比污染水平有所加重;从入海上游河道经河口至近岸海域各站位的ΣPAHs浓度分布没有明显的规律性,可能是由于不同站位悬浮颗粒物的沉降特征不同,同时在咸潮作用下导致携带PAHs污染的表层沉积物发生重新分配所致。采用PAHs组成分析和特征比值法对该区域表层沉积物当中PAHs来源进行分析,结果表明,本研究区域表层沉积物中PAHs主要为石油源污染,其次为煤等生物质燃料的不完全燃烧;沉积物污染风险评价结果表明该区域PAHs污染水平对生物产生有害效应的概率较高,需要引起相关管理部门的重视。

Polycyclic aromatic hydrocarbons （PAHs） pollution concentrations in surface sediments from Daliao River estuary and its adjacent areas （including upstream river and coastal sea areas） was detected by GC-MS, and their sources and ecological risks were assessed. The results showed that the total concentration of PAHs （EPAHs） in sedi- ment ranged from 365 × 10^-9 to 11589 ×10^-9 g/g dry weight （dw） with a mean value of 3700 × 10 ^-9 g/g dw. Com- paring with the previous reports, the pollution level increased. EPAHs concentrations had no clear distribution regulari- ty in various stations from upstream rivers to the coastal sea areas. These characteristics might be caused by the sedi- mentation properties of suspended particulate matters and the re-distribution of surface sediment with PAH pollution under the action of salt tide. PAHs composition analysis and characteristics ratios were used to analyze the sources of PAHs in surface sediments. The results suggested that PAHs in surface sediments were mainly generated from pollutionof petroleum,and followed by the incomplete combustion of coal and other biomass fuels. The results of risk assess- ments indicated that the probability of harmful biological effects caused by PAH pollution was higher in the studied re- gions, and relevant management department should pay more attention to this situation.