Source Identification, Ecological Risk and Spatial Analysis of Heavy Metals Contamination in Agricultural Soils of Tanjaro Area, Kurdistan Region, Iraq

The current work accomplished a comprehensive evaluation of heavy metals pollution in soil of agricultural areas from Tanjaro sub-district, Sulaimaniyah province, Kurdistan Region, NE Iraq. Ninety soil samples were collected from thirty different locations. Concentrations of 16 heavy metals were measured by inductively coupled plasma optical emission spectrometry ICP-OES. The pollution index (PI), potential ecological risk index (Er), enrichment factor (EF), and ecological risk index (RI) were used to assess the pollution in soil samples. High levels of Li and Ni, and moderate Ba, Cd, Hg, and Pb according to the results of concentration analysis, pollution index (PI), and potential ecological risk (ERI). High levels of Cd and Hg according to the results of Er. Agglomerative hierarchical clustering (AHC) and principal component analysis (PCA) suggested that heavy metals were generated from different natural and anthropogenic sources like natural weathering, fertilizer application, and transportation. Origins of Hg, Cd, Ni, and Pb are probably from activities like overuse of pesticides and fertilizers, whereas Pb could be exhausted from vehicle exhausts as well. Furthermore, spatial distributions revealed nonpoint source pollution for the studied heavy metals.  The obtained results help in the remediation techniques of contaminated soils such as dilution with decontaminated soil or extraction or separation of heavy metals