ASSESSMENT OF HEAVY METALS IN CONTAMINATED VEGETABLE-GROWN SOILS IN FUJIAN PROVINCE

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.