Spatial distribution and risk assessment of heavy metals pollution in soils of marine origin in central Saudi Arabia

Abstract

The present work aimed to evaluate the sources and ecological risks of heavy metal (HM) contamination in the soils of marine origin in central Saudi Arabia. HM concentrations were determined in 30 soil samples in October 2020, from Al Uyaynah–Al Jubailah region and their averages were in the following order: Al > Fe > Zn > Cr > Pb > Ni > As > Cu > Se > Cd > Hg > Sb. Average values of Zn, Ni, Co, Cr, and Cu in the investigated soils were less than averages of the continental crust, worldwide soils, and European soils, in contrast to the average values of As, Hg, Cd, and Se which were greater than the continental crust and worldwide soils. Enrichment factor, contamination factor, and degree of contamination revealed minor enriched and moderate contamination factors with As, Se, Hg, and Pb. Potential ecological risk index indicated that 93.33% of the soil samples fell under no-to-low risk, whereas 6.67% were categorized as moderate risk. Multivariate statistical analyses determined natural processes for Pb, Al, Cr, Sb, Zn, Fe, and Ni, while anthropogenic processes for As, Hg, and Se, mainly attributed to the chemicals used in agricultural applications and P fertilizers.