Improvement and case verification of potential ecological risk index assessment method for soil heavy metal contamination

Potential ecological risk index has been widely used to assess the potential ecological risk of soil heavy metal contamination.However, previous studies usually used the toxic-response factors which were suggested by Håkanson to assess the potential ecological risk of fresh lake sediments.According to Håkanson principle, this study estimated and suggested the toxic-response factors of heavy metals for the potential ecological risk assessment of soil contamination, based on the abundance of these heavy metals in upper crust, soils, fresh water, vascular plants, and human.Estimated toxic-response factor of As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, and Zn was 15, 30, 12, 10, 6, 40, 7, 7, 15, and 1, respectively.In addition, risk categories of soils contaminated by the 10 heavy metals were suggested: PERI < 160, 160≤PERI < 320, 320≤PERI < 640, and 640≤PERI represented low, moderate, high, and very high potential ecological risks, respectively.Case verification indicated these toxic-response factors and risk categories were suitable to the potential ecological risk assessment of soil heavy metal contamination.