Source analysis and risk assessment of heavy metals in development zones: a case study in Rizhao, China

The effects of heavy metal pollution in parks have caused widespread concern. This study investigated the concentrations and sources of eight heavy metals in the economic and technological development zone in Rizhao City. Geo-accumulation index (Igeo\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$I_{\text{geo}}$$\end{document}) and potential ecological risk index (PERI) were used to assess the pollution level of the development zone. Sources of heavy metals were analyzed through correlation analysis (CA) and principal component analysis (PCA). Descriptive statistics showed that many types of heavy metals accumulated in the development zone. The average concentrations of Pb, Cd, Hg, Ni, and Zn in the soil exceeded the background values of soil environment in Shandong Province. Igeo\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$I_{\text{geo}}$$\end{document} showed that only Hg in the soil was at the non-pollution to moderate pollution level. Meanwhile, sediments were polluted by Hg, Cd, and Zn, with their pollution level being higher than that of the soil. PERI showed that the soil presented moderate risk level and that the river sediment showed severe risk level. Hg and Cd exhibited the highest potential ecological risk. The results of the CA and PCA showed that the main sources of heavy metal pollution in the development zone are industrial activities, followed by atmospheric factors. Focus should thus be directed toward heavy metal pollution in development zones to protect human health and the soil environment.