Based on the investigation on 5 heavy metals at 12 sites in Dongshan Bay in August 2011,the distribution and the influencing factors of heavy metals with relations of environment in the surface sediments were discussed and the risk by heavy metal pollution was evaluated with the standard of ecological risk coefficient(Eir).The results showed that copper(Cu)content were measured between 5.53 and 22.40 mg/kg with average 15.10 mg/kg,lead (Pb)content between 28.9 and 42.6 mg/kg with average 35.0 mg/kg,zinc(Zn)content between 34.8 and 133.9 mg/kg with average 95.9 mg/kg,cadmium(Cd)content between 0.031 and 0.078 mg/kg with average 0.059 mg/kg, chromium(Cr)content between 19.2 and 91.8 mg/kg with average 62.5 mg/kg.Higher concentrations were found in the top of Dongshan Bay,and lower values were found outside the bay.Organic matters in the sediments played an important role in the distribution of heavy metals.Heavy metals(Cu,Zn,Cr)presented negative correlation with the sand(%)of big size(63~2 000 μm),while Cr showed positive correlation with clay(%)of fine particle(<1μm).Except for Cr(9 1.8 mg/kg)at the site of bay top,all heavy metals were fit in class I of the national marine sediment standard.Ecological risk coefficient(Eir)of heavy metals were in sequences of Cd>Pb>Cu>Cr>Zn and the Risk Index(RI)was lower than 90 at all sites sampled.It suggested that the sediments environment of Dongshan bay was in a good quality of low ecological risk.%根据2011年8月福建东山湾12个站位表层沉积物中5种重金属含量调查，探讨了它们的分布趋势、相互关系、影响因素，并运用潜在生态风险指数法对重金属污染进行风险评价．结果表明，该海域表层沉积物中重金属Cu含量变化范围在5.53～22.40 mg/kg之间，平均值为15.10 mg/kg；Pb含量变化范围在28.9～42.6 mg/kg之间，平均值为35.0 mg/kg；Zn 含量变化范围在34.8～133.9 mg/kg之间，平均值为95.9 mg/kg；Cd含量变化范围在0.031～0.078 mg/kg之间，平均值为0.059 mg/kg；Cr含量变化范围在19.2～91.8 mg/kg之间，平均值为62.5 mg/kg．重金属含量的分布呈现湾顶（3、11号站）高、湾外（7号站）低的格局；沉积物中有机质对重金属含量的分布起着重要作用；重金属Cu、Zn和Cr的含量随着沉积物粗颗粒组分（63～2000μm）含量的增大而降低，成负相关关系（p＜0.05）；Cr的含量随着粘土组分（＜1μm）含量的增大而增大，成正相关关系（p＜0.05）．除了湾顶3号站Cr（含量为91.8 mg/kg）以外，其他重金属元素含量均符合《海洋沉积物质量》一类标准；各元素潜在生态危害系数Eir大小顺序为Cd＞Pb＞Cu＞Cr＞Zn，所有站位重金属潜在生态危害指数RI均远小于90，属低度生态风险，表明东山湾沉积环境基本良好．
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