茅尾海海洋公园沉积物持久性毒害污染物生态风险分析

对广西茅尾海国家海洋公园海域13个站位表层沉积物进行采集，测定了沉积物中重金属Hg、As、Cu、Pb、Zn、Cd及DDTs、PCBs含量，分析了各持久性毒害污染物的分布特征，并进行了综合生态风险评价。计算结果表明:茅尾海国家海洋公园沉积物中重金属平均含量（×10-6，干重）顺序为Zn（56.9）> Pb（19.0）> Cu（12.6）> As（10.7）> Cd（0.14）> Hg（0.075），持久性有机污染物平均含量（×10-9，干重）为PCBs（1.08）> DDTs（0.70），均低于国家海洋沉积物一类标准；沉积物重金属潜在生态风险排序为Cd > Hg > As > Cu > Pb > Zn，所有站位潜在生态风险指数RI平均值为98.39，潜在生态风险总体处于较低水平，茅尾海东北部海域为潜在风险高值区，主要由于Cd的潜在风险水平较高所致；沉积物中DDTs、PCBs的含量均低于ERL值，因此DDTs和PCBs生态风险较低。

Assessment on the pollution and potential ecological risk of persistent toxic substances in the surface sediments at Maowei National Marine Park

The spatial distribution and integrative pollution effect of persistent toxic substances were discussed and evaluated based on the investigation heavy metals (Cu, Pb, Zn, Cd, Hg, As) and DDTs、PCBs in 13 surficial sediment samples collected from the Maowei National Marine Park, Guangxi.The results showed that the average concentration of heavy metals (×10-6, dry wt) followed the sequence of Zn (56.9) > Pb (19.0) > Cu (12.6) > As (10.7) > Cd (0.14) > Hg (0.075), and the average concentration of DDTs、PCBs were 1.08 and 0.70(×10-9, dry wt), respectively.All the pollution factors calculated were lower than the first class regulated by the GB 18668-2002.The order of potential ecological risks followed by Cd > Hg > As > Cu > Pb > Zn and the average potential ecological risk was 98.39, indicated a low potential ecological risk from the Maowei National Marine Park.The high value of northeastern Maowei National Marine Park was mainly due to the high potential risk of Cd.The concentrations of DDTs and PCBs of all point were lower than ERL, indicated that Maowei sea had a low potential ecological risk.