长江河口表层沉积物中PAHs的生态风险评价

2005年11月26—29日对长江河口部分表层沉积物中多环芳烃类化合物(PAHs)的污染现状进行了调查和研究，分析了其中16种PAHs单体含量. 结果表明，长江河口表层沉积物中属于美国优先控制的16种PAHs共检出15种，仅萘未被检出，w(PAHs)为355.72～2 480.85 ng/g，平均值为1 040.29 ng/g. 表层沉积物中以4环和5～6环PAHs为主，二者之和占w(PAHs)的80%以上. 长江河口表层沉积物中PAHs污染主要来源于矿物燃料的高温燃烧，但部分区域也不排除石油源输入的可能性. 与沉积物风险评估值相比，严重的生态风险在长江河口表层沉积物中不存在，然而排污口附近沉积物存在一定的生态风险. 

Discussion of Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Partial Surface Sediments of the Yangtze River Estuary

Polycyclic aromatic hydrocarbon (PAHs) pollution in surface sediments of the Yangtze River Estuary was investigated from November 26-29, 2005. Sixteen PAHs were determined. The results showed that 15 PAHs were detected among 16 kinds ofUS EPA priority-controlled PAHs except naphthalene. The total PAHs concentrations ranged from 355.72 to 2，480.85 ng/g, and the average value was 1，040.29 ng/g in the surface sediments. The PAHs in the surface sediments of the Yangtze River Estuary were dominated by those with 4-6 rings, accounting for more than 80%. The PAHs pollution in the surface sediments of the Yangtze River Estuary was mainly from combustion of mineral fuels, partly from oil pollution. Comparing with ERL and ERM valuesof risk evaluation, sediments in the stations near the sewage outlets of the Yangtze River Estuary posed a slightly high risk to consumers of bottom feeders, while serious ecological risk was not existent in the surface sediments of the Yangtze River Estuary.