Monitoring and Ecological Risks of Heavy Metals of Urban Soils in Different Functional Areas Based on Plasma Technology

Abstract

Heavy metal pollution in soil has become a global environmental problem in recent years. This study assessed heavy metals' pollution distribution, level and ecological risk in soils from different functional areas in Shihezi City, China. Heavy metals (Cr, Cu, Pb, Zn, Ni, and Cd) were measured using atmospheric pressure discharge plasma and inductively coupled plasma mass spectrometer. The mean concentration of all heavy metals in soil was higher than heavy metals' background values. The spatial distribution of Cr is the most different, and the distribution of Cu and Zn are similar in other functional regions. The single pollution index indicated that the heavy metals in industrial, traffic, and residential areas were enriched, and the pollution of Cd was more severe than others. The Nemerow pollution index showed that the near Manas River basin coast is alert (still clean), the industrial area is moderately polluted, and all other functional areas are lightly polluted. The potential ecological risk index demonstrated that only the nearshore Manas River Basin is at a mild ecological risk level, while all other functional areas are at a moderate ecological risk level. The determinate power of DEM, temperature, and precipitation were all over 65%, which meant that the topographic and climatic factors were the main factors affecting the change of heavy metal content. Secondly, socio-economic factors are important factors to promote the change of heavy metal content in soil.