Exploring soil heavy metal(loid) levels in Huraymla, Saudi Arabia: implications for sustainable agriculture and food supply

Introduction Soil contamination by heavy metals (HMs) represents an important concern for agricultural ecosystems and food security. Methods Soil samples from 34 farms were analyzed for arsenic (As), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) using ICP-AES. Geographic Information System (GIS) tools in combination with multivariate statistical analyses were applied to comprehensively assess heavy-metal contamination in the agricultural soils of Huraymala, Saudi Arabia. Additionally, contamination indices such as the Enrichment Factor (EF), Contamination Factor (CF), Pollution Load Index (PLI), and Risk Index (RI) were used to evaluate the levels of soil contamination in the study area. Non-carcinogenic and cancer risk indices were also computed. To measure vegetation density and distinguish between various types of land cover and land use, the Normalized Difference Vegetation Index (NDVI) and land use/land cover (LULC) were evaluated. Results and discussion The mean concentrations (mg kg −1 ) revealed the order: Fe (11534) > Zn (47.97) > Ni (20.80) > Cu (11.26) > Pb (7.63) > As (2.54). The PLI was 0.29 (range: 0.11–0.56), confirming that the area is relatively uncontaminated (PLI < 1). The RI indicated low to moderate concern overall. Source identification via multivariate statistical analysis suggested mixed geogenic and anthropogenic origins. The human health risk assessment indicated no significant non-carcinogenic risk. The Lifetime Cancer Risk (LCR) was negligible for Pb (< 1 × 10 −6 ) and within the acceptable range for As (1 × 10 −6 to 1 × 10 −4 ). NDVI ranged from −0.03 to 0.33. Conclusion This work provides an important reference point for understanding soil quality and potential exposure pathways in arid agricultural settings. By offering the first comprehensive geospatial and health risk evaluation of heavy metal contamination in the agricultural soils of the Huraymala region.