Ecological risk assessment of heavy metals in road dust based on improved potential ecological risk index: A case study in Zhengzhou, China

In order to analyze the ecological risk of the heavy metals in road dust. The improved potential ecological risk index was established. In the improved method, the toxicity of different chemical speciations of heavy metals were considered. Since residual fraction of Cd are non-toxic in the improved method, the results of the improved method were much lower than the traditional method.The results showed that the total risks of 3# and 15# were medium risk. The highest risk appeared on14# with the value 337.49, which belonged to high risk, and the total risk of the other sampling sites were low risk. Therefore, 14# should be the primary control site. The improved method established in this study is more scientific.