江苏启东近岸海域沉积物重金属分布特征及其潜在生态风险评价

Distribution Characteristics and Potential Ecological Risk Assessment of Heavy Metals in Coastal Sediments of Qidong,Jiangsu Province

为了揭示江苏启东近海沉积物中重金属污染特征,对2016年在近岸海域获取的10个站位沉积物样品进行了重金属含量测定,分析了江苏启东海域表层沉积物7种重金属元素(Cu、Pb、Zn、Cr、Cd、Hg和As).结果表明,沉积物中重金属的含量由高到低依次为Zn、Cr、Pb、Cu、As、Cd、Hg,其中Zn、Pb、Cu、As和Cd元素含量均大于该海域沉积物重金属含量自然背景值,意味着这些重金属元素对江苏近海海洋生态环境有着不同程度的污染.空间上,沉积物重金属污染存在明显的空间差异性,高值区主要分布在港口和河口入海处,表明近海生态环境受人类活动和陆源污染物入海影响较大.沉积物重金属地累积指数结果显示除Cd元素外,其它重金属元素污染程度相对较低.潜在生态风险指数结果表明启东近海沉积物环境重金属生态风险总体处于中等水平.因此,有必要加强对该区域人类活动所产生的重金属污染进行控制.

In order to reveal the pollution characteristics of heavy metal in the sediments of the Qidong coastal region,Jiangsu Province,we have measured the concentrations of seven heavy metal elements(Cu,Pb,Zn,Cr,Cd,Hg and As)in 10 surface sediments collected in Qidong coastal region,Jiangsu Province in 2016,and analyzed the pollution characteristics and potential ecological risks of heavy metal.The results show that the concentration of heavy metals in sediments are Zn,Cr,Pb,Cu,As,Cd and Hg in the order from high to low.Among them,the contents of Zn,Pb,Cu,As and Cd are all higher than the background value of heavy metal in Jiangsu tidal flat area,indicating that these heavy metal elements pollute the marine environment to a certain extent.There are obvious differences in the spatial distribution of heavy metal content,and the high value areas are mainly distributed in the ports and estuaries,indicating that the pollutants discharged into the sea by human activities have a great impact on the coastal ecological environment.In addition,the results of geoaccumulation index show that the pollution degree is low except Cd.The heavy metal levels generally indicated medium ecological risks,except for Cd.Therefore,it is necessary to control heavy metal contamination caused by anthropogenic activities in studied area.