珠江八大口门表层沉积物重金属污染及生态危害评价

Pollution and Ecological Hazard Evaluation of Sediment Heavy Metals in Pearl River Estuary

以2006年5月及8月采集的珠江口表层沉积物为对象进行分析,采用单因子污染指数与综合污染指数方法来分析珠江口重金属的污染现状。结果表明:单因子污染指数由高到低顺序为:Cd>As>Cu>Pb>Hg>Cr>Zn,重金属各站点达到严重污染的占1.8%,重污染的占17.8%,中等污染的占62.6%,低污染的占17.8%。综合污染水平S4和S6站点达到重污染程度,其它各站点为中等污染程度,各站点污染程度由高到低排列为:S6>S4>S5>S2>S1>S8>S7>S3。采用潜在生态危害指数法综合评价珠江口重金属潜在生态污染程度。结果表明横门站点有较高的潜在生态风险,其余各站点则属低生态风险,生态风险排列顺序为:S4>S5>S6>S2>S8>S7>S1>S3。

The sediment heavy metal of Pearl River Estuary was studied in May and August of 2006. Single factor pollution index and synthesis pollution index were used to evaluate the heavy metal pollution status, and the results showed that single factor pollution indices of different heavy metals were in sequence from high to low of Cd〉As〉Cu〉Pb〉Hg〉Cr〉Zn. Among the heavy metals we detected, the pollution level of serious heavy pollution, heavy pollution, middle pollution, low pollution accounted for 1.8%, 17.8%, 62.6%, 17.8% respectively. Among the sampling sites we studied, S4 and S6 reached heavy pollution level, and all other sampling sites were in middle pollution level. The pollution level of sampling sites from high to low was S6〉S4〉S5〉S2〉 S1〉S8〉S7〉S3. Latent ecological hazard index also was used to evaluate the latent pollution level, and the resuits showed that S4 had reached high latent ecological risk level, and others were low. The sequence of ecological risk was S4〉S5〉S6〉S2〉S8〉S7〉S1〉S3.