Comprehensive analysis of trace metal contamination in Agadir Bay sediments: Assessment of environmental impact and pollution sources.

Abstract

: Metal contamination is a widespread issue that has garnered significant attention. Therefore, monitoring actions to assess the occurrence and progression of metal pollution in aquatic ecosystems are crucial. This study assessed heavy metal contamination in the sediments of Agadir Bay at five different sites using pollution indices. The aim was to evaluate the presence of heavy metals attributable to industrial activities compared to natural background levels. The purpose of this study is to assess the quality of sediments in aquatic environments. Applying the fundamental principles of concentration measurement, index determination and comparison with established standards which vary according to the toxicity of the element, its characteristics and the natural environment - trace metals (TMEs) are used to assess pollution levels and identify their sources. Samples were taken from various sites in the study area, located in Agadir Bay, a key coastal region of Morocco. The results reveal that concentrations of all elements are below those of the upper continental crust (UCC), with the exception of arsenic and cadmium, whose average concentrations are 6.7 mg/kg and 0.6 mg/kg respectively. The geo-accumulation index indicated a slight contamination by cadmium (Cd) and arsenic (As) across all sampling stations. However, the pollution load index showed no contamination by heavy metals in this study. The ecological risk coefficient (Eri) values reveal a high ecological risk associated with cadmium at the EP and R1 stations, and a very high ecological risk at the R2, R3, and R4 stations. The enrichment of the studied sites in the Bay of Agadir with cadmium and arsenic supports the hypothesis of the role of upwelling, in addition to contributions from wastewater