Chemical Fractionation and Risk Assessment of Some Heavy Metals in Soils, Assiut Governorate, Egypt

Document Type : Original Article


Geological Sciences Department, National Research Centre, Dokki, Giza, Egypt.


Toxic elements behavior in Egyptian soil need more studies for the enhancement of soil quality and human health protection. The current study focuses on the mobility assessment of chemical species of As, Pb, Cr, Ni, Cu and Co in soils due to anthropogenic emission using sequential extraction (SE) and risk assessment code (RAC). Generally, the studied soils are alkaline calcareous loam soil. It has a low organic matter (OM) that ranges from 1 to 3.8% and is enriched with As, Pb, Cr, Ni, Cu and Co, which preferentially accumulate in soil clay and silt fraction. SE revealed that the non-residual (bioaccessible) fraction contains about (70.7%) As, (65.2%) Co, (58.8%) Cr, (28.4%) Cu, (6.8%) Ni and (64.5%) Pb, indicates the risk of pollution with As, Co, Cr, and Pb. RAC values indicated a high risk of soil pollution with As, medium risk of Co and Pb, low risk of Cu and Ni, and no risk of Cr. The results pointed out the geogenic source of Cr, mixed source of Co, Cu, and Ni and the anthropogenic source of As and Pb. The spatial distribution analyses of these metals indicated the role of urbanization, traffic, and industry on the releasing of toxic metals into the environment.


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