长江下游典型滨海地区农业土壤重金属污染特征

为揭示长江下游滨海地区农业土壤重金属污染状况,以滨江临海的南通市为例,网格化布点,采集表层农业土壤样品共计334个,对其重金属Cu、Pb、Cr、As、Hg含量进行了测定分析.结果表明,研究区域表层农业土壤中各重金属含量均已超过其背景值,且以Pb污染最为严重;区域性差异较大,以滨海的如东、海门、启东污染最为严重,且以海门、启东As含量最高;各重金属间相关性不显著,来源途径不止一种.从而提出南通市农业土壤重金属污染的防治应立足于防重于治的方针,着重滨海地区,以Pb、As污染源为主,并对污染土壤进行修复.

Analysis on Heavy Metal Pollution Characteristics of Agriculture Son in Typically Coastal Areas of the Lower Yangtze River

To investigate the status of heavy metal contamination in the coastal agriculture soil of the lower reaches of the Yangtze River,the study was conducted in Nantong,Jiangsu province.Totally 334 samples of topsoils were collected gridding design and concentrations of heavy metals Cu,Pb,Cr,As and Hg in the soil samples were determined.First of all,statistical analysis of the test results indicated that the heavy metals in the studied soil all exceeded the background values of the region,and Pb was 1.7 times.Although the concentrations of a few metals slightly exceeded their background values,the spatial variations of the concentration of those metals were significant.The concentration of heavy metals in Rudong,Haimen and Qidong were higher than other regions,and As concentration in Haimen and Qidong was respectively 92.3%,170.5% higher than the background values.Except for Pb and Hg,Pb and As,no correlations between the contents of five heavy metals were existed,which suggested that those have more than one sources.Consequently it is essential to give priority to prevention rather than remediation in Nantong area,and the pollution control should be intensified in coastal regions with Pb and As pollution sources,and measures taken to remediate the polluted soil.