Assessment of Pollution Indicators and Source Apportionment of Heavy Metals in Agricultural Topsoils of the Middle Euphrates Region, Iraq

greater than 5 g cm -³.Although these elements occur naturally, anthropogenic activities including industrial operations, agricultural practices, mining, and waste incineration are substantially elevating their concentrations in agricultural environments, thereby disrupting their natural biogeochemical cycles (Xu, Jin and Zeng, 2024).A critical concern is their environmental persistence, as they are non-Abstract | This study assessed contamination levels and identified the potential sources of heavy metals (Pb, Ni, Cr, and Cu) in agricultural soils of Iraq's Middle Euphrates region using geochemical indices (Igeo, EF, CF, PLI).Analysis of 50 surface soil samples from cultivated, fallow, and pollution-proximal areas revealed distinct patterns: the Contamination Factor (CF) indicated moderate to considerable contamination by Pb, Ni, and Cr (maximum CF values of 6.0, 9.95, and 6.0, respectively), whereas Cu showed generally low contamination (CF = 0.81-3.43).The Enrichment Factor (EF) moderate to high enrichment for Ni (0.76-6.55) and a range from deficiency to moderate enrichment for Pb (0.56-3.95), whereas Cu and Cr displayed lower enrichment factors (0.40-2.95 and 0.63-4.08,respectively).An integrated assessment using the Pollution Load Index (PLI) confirmed moderate to considerable overall metal accumulation (1.11-5.85).Source identification based on Igeo and EF indicated suggested mainly geogenic origins for Pb and Cu, a pronounced anthropogenic contribution for Ni, and mixed lithogenic-anthropogenic sources for Cr.These results underscore the urgency of adopting sustainable land management and targeted monitoring to mitigate contamination, protect soil resources, and reduce human exposure via the food chain.