Heavy metal contamination and ecological-health risk evaluation in peri-urban wastewater-irrigated soils of Beni-Mellal city (Morocco)

Abstract

The present study evaluated the metal contamination and its detrimental effects in agricultural soils irrigated by wastewater at the region of Béni-Mellal. A set of soil proprieties (texture, pH, EC, OM, CaCO₃) and heavy metals (Cd, Cr, Cu, Pb, Zn, Fe) were measured. Soil contamination level and risks were assessed using geoaccumulation index (Igeo), contamination factor (CF), enrichment factor (EF) and pollution load index (PLI), ecological risk (RI), hazard quotient (HQ), and non-carcinogenic risk (HI) for ingestion exposure. Results showed that mean levels of all metal elements, except Pb, in agricultural soils were higher than the local background values. Igeo, CF and EF indices revealed a moderate to high soil contamination by heavy metals, as confirmed by PLI index suggesting an anthropogenic source of these elements. The RI index indicated a considerable ecological risk, whereas HQ and HI indices suggested no obvious non-carcinogenic risk to adults and non-carcinogenic risk to the children population.