Assessment of Potentially Toxic Elements in the Urban Soil and Plants of Kirkuk City in Iraq

Abstract

Kirkuk city is known for its industrial activities, especially oil and cement production, as well as its road traffic. The aim of this study was to assess potentially toxic elements (PTEs) in the soil and plants from urban areas by measuring pollution indices and estimating the effect that this pollution has on the environment. Leaf and soil samples were taken from 10 different locations in Kirkuk. These samples were pre-treated using the acid digestion method and concentrations of 12 elements were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results indicate a high content of aluminum and magnesium (mg/kg) in the soil samples from all study sites. For leaf samples, the results showed a moderate to low amount of magnesium and aluminum. Based on our results, the PTE concentrations were found in the following order—Mg > Al > Ni > Cu > Cr > Pb > Co > As > Se > Cd > Hg > Ti—in leaf samples from all 10 study sites. However, in the soil samples, PTE concentrations were in the following order—Mg > Al > Cr > Ni > Cu > Pb > Co > As > Se > Ti > Cd > Hg—from all study sites. Pollution indices showed a moderate level of contamination of Pb, Cd, and Ni, and a high level of contamination of As and Hg in plant and soil samples from all study sites in Kirkuk city.