Geochemical distribution characteristics of 26 geochemical indexes were studied based on the geochemical survey of submarine sediments and seawater in Qiansan Island,Lianyungang,Jiangsu Province.The results show that the evaluating results of most indexes are well-distributed and close to corresponding background values,and the quality of submarine sediments and seawater is good;nevertheless,a few locations of the sea area exhibit relatively high evaluating values of different indexes,some of them have the potential environmental risk,and a few of the heavy metals exceed the environmental standards.On such a basis,3 risky areas (blocks or locations) and some potential risky locations were preliminarily delineated,and risky indexes such as As and Pb and some other potential risky indexes containing Cd,Ba,MnO were successfully determined.The qualities of the sediments in this area are classified into 3 levels,i.e.,clear level,sub-clear level and weakly contaminated level.The original source and evolutionary trends of some risky and potential risky indexes such as As,Pb and Ba are tentatively discussed with the purpose of providing some preliminary models or recommended plans for prompting the future construction and other activities in the coastal area of Jiangsu Province.%通过对前三岛海域进行海底沉积物和海水地球化学调查,研究了26项地球化学指标分布特征.结果显示,该海域沉积物中大部分指标属于均匀型分布且与背景值总体接近,海底沉积物及海水质量总体良好,但局部地点也存在部分指标含量较高,甚至个别指标超标的现象,存在生态风险.鉴于此,经过相关评价初步圈定了该海域的3块(点)风险区和潜在风险区位置,明确了As和Pb为风险指标,Cd、Ba、MnO等为潜在风险指标,对前三岛海域沉积物质量分为清洁区、尚清洁区、轻度污染区3个级别,并尝试讨论As、Pb、Ba等风险及潜在风险指标的成因和演化趋势,为该区沿海开发利用提供了参考,为其他海域相关工作提供了借鉴.
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