通过测定长江口滨岸9个典型采样点上覆水与表层沉积物样品中的多环芳烃(PAHs)污染水平,分析其组成、时空分布特征及其影响因素,并进行了生态风险评价.结果显示,枯季上覆水中PAHs浓度高于洪季,平均浓度分别为1 988 ng/L和1 727ng/L;表层沉积物中的PAHs也为枯季高于洪季,平均浓度分别为1 154 ng/g和605 ng/g;Phe是水和沉积物中PAH的主要成分.温度是控制上覆水中PAHs季节性差异的主要因素,而有机碳(OC)与碳黑(SC)则控制着沉积物中PAHs的富集;长江口滨岸复杂的水动力条件与各种人类活动产生的污染物输入影响了PAHs的空间分布,在一定程度上也导致了河口滨岸PAHs来源的复杂性.生态风险评价结果显示,长江口滨岸水-沉积物间的PAHs在一定程度上可能对该区生物造成潜在不利影响.其中,上覆水中个别PAH化合物的浓度水平已达到欧美等国生态毒理评价标准或超过了美国EPA水质标准,BaP浓度超过了我国地表水环境质量标准的规定浓度;表层沉积物中部分PAH化合物的含量超过了ER-L值和ISQV-L值.
Polluted levels,temporal and spatial distributions of polycyclic aromatic hydrocarbons(PAHs) were studied in overlying water and surface sediments from nine typical sampling sites in the Yangtze estuarine and coastal areas.The results showed that PAHs concentrations in overlying waters and surface sediments in dry season(1988 ng/L and 1154ng/g) were both higher than those in flood season(1727 ng/L and 605 ng/g.) And phenanthrene(Phe) was dominant among PAH compounds.Temperature was the most important factor that controlled PAHs seasonal variation in overlying waters,while organic carbon and soot carbon influenced PAHs accumulation in surface sediments.Complicated hydrodynamic conditions and pollutant inputs caused by various anthropogenic activities not only affected on PAHs spatial distribution,but also led to complicated sources in the Yangtze estuarine and coastal areas.Ecological risk assessment indicated that PAHs in water-sediment system from the Yangtze estuarine and coastal areas might potentially damage the Yangtze estuary ecosystem to some extent.Some of PAH compounds in overlying waters had exceeded the ecotoxicological assessment standard or EPA National Recommended Water Quality Criteria,and BaP also exceeded the normal concentration of Chinese Environmental Quality Standards for surface water.Some of PAH compounds in surface sediments had exceeded the effects range low(ER-L) levels and ISQV-L values.