采集了福建省26个县市158份菜园表层土壤样品,测定了土壤样品中重金属含量,采用单项及综合污染指数法对土壤重金属污染进行评价分析,并通过元素相关性分析和聚类分析,研究了菜园土壤重金属元素的赋存特征与区域分布.结果表明,福建省菜园土壤存在着不同程度的重金属污染,主要污染元素为Pb,Hg和Cd;元素相关性分析与聚类分析的结果表明:Cu,Zn,Ni和As具有伴随污染的特点,其污染源主要来自土壤母质和大量施用的农药和化肥;Cd,Pb和Hg在土壤中各聚成一类,说明它们在菜园土壤具有较独特的污染源,特别是Cd和Hg,其污染特征明显.而Pb和Cd虽有各自的污染源,但其污染具有一定的相关性.
Concentrations of heavy metals in 158 top-soils collected in 26 cities in Fujian Province are measured, and the contamination of heavy metals in soils is assessed with single-factor pollution index and Nemerow comprehensive pollution index. In addition, the regional distribution and pollution sources of heavy metals in soils are also investigated with the methods of elemental correlation analysis and cluster analysis. The results show that most of the soils in the sampled areas are contaminated to some extent, with heavy metals including Pb, Cd and Hg. The results of correlation analysis show that Cu, Zn, Ni and As are the concomitant elements in soils, which indicates that these elements commonly exist together in the pollutants such as parent soil material, and agricultural pesticides and fertilizers. However, Cd, Pb and Hg in soils are found to be separately self-existent based on the cluster analysis, which shows that each of the elements, especially Cd or Hg, may come from the definite pollution sources. But a correlation between Cd and Pb is observed to present in soils although each of metals owns its pollution sources. The results indicate that the contamination of heavy metals in soils may be effectively identified and characterized with the methods of correlation analysis and cluster analysis.