Grade division method for soil geochemical contamination and its application

Abstract：Grade division method for soil geochemical contamination has been established on the basis of the concentration and accumulation grade caused by human exploitation of toxic elements. A preliminary study in the Yangtze River delta and the coastal region of Fijian Province shows that the sediments or parent materials of deep and top soils are of homo-genesis and their element concentrations have good correlation. Geochemical baseline based on deep soil geochemical data can undoubtedly be selected as the reference value to assess soil contamination because deep soil has not been affected by human activity and pollution. Soil geochemical contamination grade standard of the Yangtze River delta was thus set up, and soil contamination of the region was divided according to the standard. The origin and eco-geochemical effect of each contamination grade are discussed in this paper. However, the eco-geochemical effects of soils of different contamination grades need further investigation.