福清湾表层沉积物重金属分布及生态风险评价

Distribution and ecological risk assessment of heavy metals in surface sediments of Fuqing Bay

为了解福清湾表层沉积物重金属的污染现状及其潜在生态危害程度,以及重金属和有机质含量的相关性,于2009年6月和8月对福清湾表层沉积物重金属和有机质含量展开调查,利用单因子指数法和Hakanson潜在生态风险指数法对其进行综合评价。结果表明,福清湾表层沉积物Cu、Pb、Cd、Hg、As和有机质平均含量分别为17.4×10-6、31.7×10-6、0.058×10-6、0.079×10-6、8.90×10-6和1.31%,均符合一类海洋沉积物质量标准,质量状况良好。各重金属元素之间呈正相关,与有机质呈正相关关系尤为明显。沉积物重金属单因子指数依次为Pb(1.27)>As(0.59)>Cu(0.58)>Hg(0.40)>Cd(0.12),重金属综合污染指数为2.96,为低污染水平;单项重金属潜在生态风险参数依次为Hg(15.8)>Pb(6.35)>As(5.94)>Cd(3.48)>Cu(2.91),潜在生态风险指数(RI)为34.5,属于低潜在生态风险。

In order to understand the Fuqing Bay surface sediments, heavy metals pollution status and its po- tential ecological hazards, as well as heavy metals and organic matter content in the correlation, we investiga- ted Fuqing Bay surface sediments, heavy metals and organic matter content from June to August in 2009, and used single factor index method, and Hakanson potential ecological risk index to evaluate comprehensively. The results showed that, Fuqing Bay surface sediments of Cu, Pb, Cd, Hg, As and organic matters, the av- erage content were 17.4 × 10-6, 31.7 x 10-6, 0.058 × 10-6, 0.079 × 10-6, 8. 90 × 10-6 and 1.31%, which were consistent with a type of marine sediment quality standards that means it has good quali- ty. A positive correlation of heavy metals, especially a positive correlation with organic matter was obvious. Heavy metal single factor index in decreasing order was： Pb （1.27） 〉As （0. 59） 〉Cu （0. 58） 〉Hg （0. 40） 〉 Cd （0. 12）, heavy metal pollution index was 2. 96 for the low -pollution level; individual potential ecological risk of heavy metals parameters were Hg （15.8） 〉Pb （6.35） 〉As （5.94） 〉Cd （3.48） 〉Cu （2.91）, the poten- tial ecological risk index （R/） was 34. 5, which indicated that Fuqing Bay existed a low potential ecological risk.