Spatial distribution and health risk assessment of heavy metals pollution in soil within Agricultural and industrial areas in the Eastern Province, Saudi Arabia

Abstract

This study aimed to explore the level of heavy metal contamination in the soil of agricultural and industrial areas in the Eastern Province of Saudi Arabia. It adopted a novel approach integrating multiple disciplines including sampling, laboratory analysis, spatial analysis, and risk evaluation. The research focused on pinpointing levels of contamination, identifying their sources, and evaluating associated ecological and human health hazards. Due to its varied agricultural and industrial activities, the Eastern Province faced potential environmental challenges linked to heavy metal pollution. This study tackled the essential task of understanding the spatial spread and associated risks of heavy metals in soil, offering insights critical for effective environmental management and policymaking. Over 60 soil samples were gathered from different industrial and agricultural sites. Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES) was employed for the analysis of various heavy metals in these samples. The soil samples underwent evaluation for heavy metal presence, with their pollution levels assessed through indicators such as the heavy metal pollution index (HPI), heavy metal evaluation index (HEI), modified heavy metal index (MHMI), and degree of contamination (Cdeg). Experimental findings revealed average concentrations of heavy metals in mg/Kg for As, Ba, Hg, Pb, Ni, V, Cd, Cr, Cu, and Zn are 1.21, 110.62, 0.08, 6.34, 8.95, 9.98, 1.18, 31.79, 6.76, and 23.44 respectively. A general trend emerged in the concentration levels, with the highest averages observed in samples from industrial areas, followed by agricultural sites. Particularly notable were barium concentrations in the industrial area, peaking at 1966.5 mg/kg, and copper levels, with a maximum of 95.75 mg/kg in the same area, occasionally surpassing the permissible limits. This methodology provided crucial insights for enhancing water environment management and protection, addressing the urgent need for effective environmental governance and policy development. The findings from this project are not only relevant to the Eastern Province but also applicable to other regions experiencing similar soil contamination challenges.