The study of metal (As, Cd, Pb, Zn and Cu) contamination in superficial stream sediments around of Zaida mine (High Moulouya-Morocco)

Abstract Sediment pollution, affected by both natural and anthropogenic factors, significantly decreases the environmental quality. In this study, five hazardous metals (Pb, As, Cd, Zn and Cu) have been studied in surface sediments around the mining disctrict Zaida, in Northeastern of Morocco. The concentrations of these metals were measured in sediment samples collected from the Moulouya River, the Ansegmir tributary and the Hassan II Dam located downstream of the abandoned Pb mine. In addition to some statistical analyses, the geo-accumulation Index, Potential Ecological Risk, and other pollution indices were used to assess pollution levels and associated risk may be caused by these metals. The observed values of the contamination factor and the geo-accumulation Index revealed a high Pb contamination downstream of the tailings. As for the Potential Ecological Risk, an extreme contamination is shown by the As in some of the studied samples. The correlation results suggested that Pb and As are from different sources. In fact, the tailings located near the Moulouya River can be considered as substantial sources of Pb, while the As can be related to lithogenic or anthropogenic sources.