江苏如东滩涂贝类养殖区表层沉积物中重金属来源分析及其潜在生物毒性

通过2010年对江苏如东滩涂贝类养殖区表层沉积物中重金属Cu、Zn、Pb、Cd、Hg、As含量的调查分析,应用地质累积指数(index of geo-accumulation,Igeo)对各重金元素的污染状况进行了评价,结果表明重金属污染可分为3类:Cu、Cd、Hg为无污染;Pb、As为中～无污染;Zn为中度污染,重金属污染程度顺序为Zn>As>Pb>Cd>Cu>Hg.根据沉积物质量基准(sediment quality guideline,SQG),表层沉积物中Cd、As的含量在各采样站位分别表现为无潜在生物毒性效应,偶尔有潜在生物毒性效应,Cu、Pb、Zn、Hg的含量则在部分采样站位偶尔有潜在生物毒性效应,其中仅有Zn在部分采样站位有频繁发生的潜在生物毒性效应.毒性单位评价(toxic unit,TU)结果表明,仅有1个采样站位具有明显的急性毒性,其余站位无急性生物毒性效应.主成分分析(principal component analysis,PCA)的结果表明,前2个主成分的贡献率分别为37.56%、33.71%,揭示了重金属污染主要有2个来源:工业点源排污和交通航运污染源.

Analysis of the Source, Potential Biological Toxicity of Heavy Metals in the Surface Sediments from Shellfish Culture Mudflats of Rudong Country, Jiangsu Province

Concentrations of six heavy metals were measured in the surface sediments from shellfish culture mudflats of Rudong Country,Jiangsu Province in 2010.The geo-accumulation Index(Igeo) was employed to evaluate the pollution level of heavy metals and the results showed that the heavy metal contamination could be divided into three groups: no contamination(Igeo),as in the case of Cu,Cd,Hg;light to moderate contamination(0As>Pb>Cd>Cu>Hg.The potential biological toxicity was analyzed using sediment quality guidelines(SQG),as the guideline values,Cd showed no potential biological toxicity,As showed occasional potential biological toxicity in all sampling stations,Cu,Pb,Zn,Hg showed potential biological toxicity in some sampling stations,whereas Zn was the only one showing frequent potential biological toxicity in some sampling stations.∑TUs revealed that only one of the sampling stations showed significant acute toxicity,whereas the others showed no acute toxicity.Analysis of heavy metal contamination source through principal component analysis(PCA) revealed that the contribution rates of the top two principal components were 37.56% and 33.71%,respectively,indicating that the two main sources of heavy metals were industrial waste water and pollution from transportation and shipping.