Assessment of Heavy Metal Pollution and Sources Identification in Urban Soil Using Pollution Indices and Statistical Analysis, Mosul, Iraq

This study aims to assess heavy metal pollution and identify its sources in the surface soil of Mosul's left side. Thirty-one composite soil samples were collected using a regular grid distributed over the study area with 2 × 2 km dimensions. Chemical analysis was conducted using the X-ray fluorescence (XRF) technique to determine the concentration of trace elements (V, Nb, Zr, Y, Th, Sn, Cr, Sb, As, Mn, Mo, Co, Cu, Zn, Ni, Pb) and major oxides (MgO, Al₂O₃, SiO₂, K₂O, TiO₂, Fe₂O₃). The calculations of soil pollution indices (contamination factor, degree of contamination, geo-accumulation index, Nemerow pollution index, enrichment factor) indicate that most study samples are contaminated with heavy metals. Principal component analysis shows the influence of geochemical processes such as chemical weathering and surface adsorption, as well as sedimentary processes like river deposition, in redistributing these elements in the environment. Meanwhile, it appears that the heavy metals (Cu, Zn, Pb, Sn, Sb, Mo) were affected by human activities in the city, particularly since these elements are clear indicators of pollution resulting from industrial waste such as batteries, metal coatings, and electronic waste, as well as the impact of military activities during the city's liberation from terrorist gangs. This is supported by the high concentrations of these elements in the industrial area. This study highlights the interaction of natural geological and geochemical factors with human factors in influencing the concentrations of heavy metals in the surface soil of Mosul City. The study also emphasizes the urgent need to take immediate measures to reduce soil pollution in the city, particularly after pollution indices in some areas have recorded high levels of contamination.