Environment Quality Evaluation of Heavy Metals in Agricultural Soils of Shilou Town in Fangshan District of Beijing

Abstract

Concentration of 7 heavy metals in 269 topsoil samples were determined which collected from Shilou town of Fangshan district in Beijing, and the data was analyzed by the single factor index and the Nemerow index for the soil environment quality evaluation. The mean values of the heavy metals were 8.24 ± 1.42, 0.209 ± 0.07, 62.99 ±8.89, 0.133 ± 0.11, 25.29 ± 5.02, 23.91 ± 5.72 and 86.29 ± 28.13 mg kg-1 for As, Cd, Cr, Hg, Cu, Pb, and Zn, respectively. Average concentration of As, Cd, Cr, Cu and Zn exceeded the background value of Beijing area. It was found that all heavy metals were not in normal distribution. The soil environment quality was evaluated by single factor pollution index and Nemerow index of heavy metals. The order of single factor index was Cd, Zn, Hg, Cu, Cr, Pb, As in decreasing. Average Nemerow index of soil was 0.918. This value was reached to the grade III standard of soil environmental quality assessment classification.