Geochemical formatives and risk assessment of heavy metals in the near-shore sediments of the Red Sea, Egypt

The Red Sea's near-shore zones were thought to be nurseries and grazing grounds for the various economic fish species. To illustrate the relation between human health and seafloor sediments, the geological and geochemical properties of seafloor sediments were investigated in near-shore zones at each of Mersa Alam and Hurghada cities along the Red Sea. The obtained data illustrated that the sediment nature at Hurghada is primarily of biogenic origin, as indicated by the high carbonate contents; however, the sediment nature at Mersa Alam is attributed mainly to the terrigenous origin. Accordingly, the studied heavy metals at both localities showed different feeding sources; Mersa Alam sites showed high levels of; Fe, Mn, Zn, Ni, and Cu attributed to terrigenous inputs; however the high averages of Cd and Pb at Hurghada pointed accusingly to land-based and human activities. Geochemically and as indicated by the statistical parameters; Correlation coefficient, PCA and Geo-accumulation ( I _geo ); Mn, Zn, Cu and Ni were found mainly in association with Fe in the same source of accumulation and similar geochemical forms. However, the adsorption over sediment particles and/or assimilation inside the carbonate lattices are possible occurrences of Cd, Pb, and partially Ni. The calculated risk assessment parameters and Carcinogenic Risk (ILCR) don’t show any threats for marine organisms and humans consumption.