The long-term evolution model of metallic contamination of Monastir-Sayada Coast as deduced from the geochemical and statistical analysis

Abstract

Abstract Coastal regions are especially susceptible to both natural and human-induced pressures, and it is crucial to evaluate these pressures. This research aims to investigate the monitoring of human activities through river discharges in order to identify potential ecological risks and examine the long-term changes in metallic contamination in Monastir-Sayada. To accomplish this, four sediment samples were collected from various locations along the Monastir coast, specifically near the source of pollution, to analyse the concentrations of heavy metals like Zinc (Zn), Cadmium (Cd), Copper (Cu), Lead (Pb), Manganese (Mn), Nickel (Ni), and Iron (Fe). The findings indicate that the average concentrations of these metals in the sediment cores followed a descending order of Fe > Zn > Mn > Cu > Cd in front of the Monastir effluent, Fe > Mn > Zn > Pb > Cd > Cu > Ni in the effluent at Frina region, Fe > Mn > Zn > Cd > Ni > Pb > Cu in the Melah stream, and Fe > Mn > Cd > Zn > Cu in front of the Essouk stream at Lamta. Based on the enrichment factor (EF) and contamination factor (CF), the long-term evolution of the Monastir-Sayada coast is considered highly polluted for Pb and Cd, posing a relatively high potential ecological risk. The heavy metals are believed to originate from similar human activities, as indicated by the principal component analysis (PCA) and cluster analysis (CA). Pollution from heavy metals can have long-lasting effects on coastal sediments, emphasizing the importance of preventing such pollution in the first place.