Assessment of contamination marine sediments from Dakar coast (Senegal) by chlorine and metallic elements (Cu, Zn and Cr)

Abstract

Coastal marine ecosystems are increasingly affected by human activity due to urban and industrial discharges. The objective of this study is to assess the state of pollution in chlorine and metals (copper, zinc and chromium) of the marine sediments in the Dakar coast. The samples were taken, using a hand grab at depths of 5 cm, at the three sites studied (Ngor, Hann and Soumbedioune). Chlorine, copper, zinc and chromium were measured by photometric method. The results of the analyses showed that the sediments of Soumbedioune and Hann are more contaminated than those coming from Ngor area. The geo-accumulation index of metals showed contamination in the order Cu>Cr>Zn and the comparative study shows that the sediments of Soumbedioune are more loaded with chlorine 2 than those of Hann and Ngor areas. These results constitute basic data for environmentalists but also for those working in the protection of coastal areas and marine organisms.