Potential Ecological Risk Assessment of Heavy Metals in Iraqi Soils: Case Studies

Abstract

The aim of this study is to estimate the potential ecological risk of heavy metals in soils in different cities, Iraq. The used data was obtained from previous published studies. The index of ecological risk ($ErI$) and index of the overall potential ecological risk (RI) were calculated employing Hakanson’s methodology. Generally, the obtained results showed that Cd was the major contributor to the potential risk in soils of Baghdad, Basrah, Duhok, Erbil, Fallujah, and Kirkuk cities. In soils of Al-Nasiriya, Babylon and Hawega cities, the major contributor to the potential risk is Ni element. The spatial distribution of the RI showed that heavy risk was recorded in Baghdad city soil and moderate risk in soils of Basrah, Duhok, Erbil and Kirkuk while the risk in soils of the other cities was light. The spatial distribution reflects impact of the anthropogenic activities as a source of the metal pollution of the soils. The results showed that the factor controlling the estimation of $E_{r}^{i}$ was the reference level value of the metal and using different reference values leads to overestimation or underestimation of the E_r and in turn RI. This work represents the first attempt to assess the ecological risk of heavy metal in Iraqi soils except Baghdad’s soil.