海南岛南部海域沉积物重金属污染及潜在生态风险评价

通过对海南岛南部近岸海域49个表层沉积物的重金属元素含量的分析,结合沉积物的粒度组成特征,探讨了重金属可能的来源并评价了重金属的污染状况和潜在生态风险。结果表明,表层沉积物以砂和粉砂为主,砾石和黏土含量相对较少。重金属平均含量较低,最高是Zn元素,为38.98 mg/kg,大部分属于国家海洋沉积物一类标准。除As元素之外,Zn、Cu、Cd、Pb、Cr和Hg 6种重金属元素之间具有明显的正相关性,与粉砂和黏土等细颗粒沉积物也具有显著的正相关。潜在生态危害指数的评价结果显示,海南岛南部近岸表层沉积物中的重金属对海洋生态系统的危害非常轻微,不同重金属元素的潜在生态危害系数大小顺序为AsHgCdPbCuCrZn,其潜在生态风险指数RI平均值为14.55,属于轻微的潜在生态危害。

Heavy metal pollution and their ecological risk assessment in sediments from southern Hainan Island

A total of 49 surface sediment samples from Southern Hainan Island were analyzed for heavy metals and grain size in order to identify their possible sources and assess their potential ecological risk. It showed that the surface sediments consist mainly of sand and silt and with scarce gravel and clay. The mean concentrations of the selected heavy metals were relatively low from the Southern Hainan Island with the highest reached to 38.98 mg/kg of Zn. Except for As, the other elements (Zn, Cu, Cd, Pb, Cr and Hg) exhibit significant positive correlations with each other and the contents of silts and clays. The assessment result of ecological risk revealed the Southern Hainan Island possessed light potential ecological risks with the mean RI value of 14.55. The order of ecological risks for the selected metals is As>Hg>Cd>Pb>Cu>Cr>Zn.