Heavy Metal Pollution and Health Risk Assessment of Soil and Vegetable in a Sewage-Irrigated Area

Concentrations of As,Pb,Cr,Cd and Hg in soil and vegetable in a sewage-irrigated area in Bengbu,Anhui Province were monitored and analyzed.Heavy metal pollutions of the soil and vegetable produced therein were evaluated using the single factor index and Nemero index of pollution,and health risk of the vegetable was assessed using the EPA MMSOILS model.Results show that the average concentration of As,Pb,Cr,Cd and Hg in the soil was 4.182,3.685,1.397,0.381 and 0.151 mg·kg-1,respectively.The concentration of Cd was well over the criterion in Grade Ⅱ of the Standard for Soil Quality(GB 15618-1995)(6.5 pH 7.5),with its single-factor pollution index reaching 1.27.The concentrations of Hg,Pb,Cr,Cd and As in vegetable were in the range in compliance with the Food Sanitation Standard(GB 2762-2012),which suggests that the vegetable produced in the sewage irrigated area is not risky.The heavy metals detected in the vegetable displayed an order of Pb As Cr Cd Hg in terms of content.Among the heavy metals in vegetable,As was the highest in risk,reaching 1.12 in hazard quotient,while the others were 0.40,0.07,0.12 and 0.06,separately,displaying an order of As Pb Hg Cd Cr.