粤东青澳湾表层沉积物重金属含量分布特征和污染评价

测定了粤东青澳湾表层沉积物的7种重金属和总有机质的含量,分析了其分布特征及彼此之间的相关性,并运用海洋沉积物质量标准、富集系数和生态危害指数等方法对重金属的污染进行了综合评价.结果表明,该海域各重金属元素含量的平均值分别为:Cu(34.51 mg/kg)、Pb(41.89mg/kg)、Cd(0.11 mg/kg)、Zn(80.21 mg/kg)、Hg(0.039 mg/kg)、As(15.61 mg/kg)、Cr(29.41mg/kg).所有元素(Cu除外)都未超过《海洋沉积物质量》一类标准,且所有元素都远低于美国国家海洋和大气局(NOAA)提出的中值区间效应值(ERM),这表明本海域生态风险很小.整个海域各重金属元素的富集系数大小顺序:Pb>Cu>As>Zn>Cr>Cd>Hg,表现出主要以Pb(1.68)和Cu(1.15)为主的富集.各重金属元素生态风险大小顺序:As>Pb>Hg>Cd>Cu>Zn>Cr,而且所有站点重金属的危害综合指数RI都远低于轻微级别(150),没有表现出潜在生态危害.

Distribution characteristics of heavy metal contents in surface sediment of Qing' ao Bay, Guangdong and the contamination assessment

Total organic matter and heavy metals,including copper（Cu）,lead（Pb）,cadmium（Cd）,zinc（Zn）,mercury（Hg）,arsenic（As） and chromium（Cr） were determined in surface sediments collected from Qing＇ao Bay,eastern Guangdong province.Distribution characteristics and correlation among them were analyzed.Integrated assessments of these contaminants were also conducted based on the sediments quality guidelines,enrichment coefficient and index of potential ecological risk,etc.The results showed that the mean of each heavy metal was Cu（34.51mg/kg）,Pb（41.89 mg/kg）、Cd（0.11 mg/kg）,Zn（80.21 mg/kg）,Hg（0.039 mg/kg）,As（15.61 mg/kg） and Cr（29.41 mg/kg）,respectively.The pollution levels of all these trace metals were low and didn＇t exceed the class one for marine sediment standard（except for copper） formulated by China and the effects range-median（ERM） proposed by NOAA.As to the enrichment coefficients,the order was PbCuAsZnCrCdHg.Pb（1.68） and Cu（1.15） were the predominant elements to accumulate in this area.The potential ecological risk was low as risk indices（RI） were far below 150 and the order was： AsPbHgCdCuZnCr.