Potential ecological risk from Cd and As in agricultural soils near wastewater sources and a landfill in the West Bank, Palestine

Abstract Acid-extractable concentrations of Cr, Mn, Cu, Zn, As, Cd and Pb were measured by ICP-MS in 80 composite topsoil samples collected from five agricultural sites in the West Bank, Palestine, near wastewater sources or a landfill. Pollution indices calculated relative to continental-crust values differed among sites but are conditional on the partial extraction and selected background. Mean sample-level PLI classified ADJ (1.12), EQR (1.23) and DSN (1.33) as polluted. Cd had the highest I geo at ADJ (3.1), and Fe-normalized EF classified Cd at ADJ as extremely enriched. An Al-normalized sensitivity analysis preserved the principal Cd, As, Zn and Cr patterns but changed four of 35 site–metal EF classes. Mean RI was highest at ADJ (424.5; considerable screening risk), followed by DSN (150.7; at the low–moderate boundary); Cd contributed 93% and 73% of RI at these sites. A validated 5 × 4 self-organizing map produced four stable compositional clusters. Exploratory three-factor PMF identified Cr-rich soil-matrix, Cd–Zn-enriched mixed and Mn-dominant signatures, although residual over-dispersion, rotational ambiguity, weak reconstruction of Cu, Zn and Pb, and site dependence precluded quantitative source attribution. These screening results identify Cd, particularly at ADJ, as a priority for confirmatory monitoring. They do not establish total metal contents, bioavailability, food-chain exposure or unique pollution sources.