Heavy metals contamination in seawater, sediments and seashells of the Gulf of Suez, Egypt

A comprehensive environmental assessment of the Abu Zenima coast, Egypt, was done by evaluating the heavy metal pollutant levels in sediments, marine seashells, and seawater. Environmental parameters as the geoaccumulation index, contamination factor, enrichment factor, soil pollution index and potential ecological risk index proved that the study area was very severely enriched with Cd, severely enriched with Pb, and moderately enriched with Zn. However, these pollutant levels were still lower than some standardized reference values. Furthermore, the bioaccumulation index indicated that gastropod shells had greater ability to concentrate Fe, Cd, Ni and Zn than pelecypod shells, which may be attributable to the shape of the gastropod shell. Regarding the seawater samples, Pb, Cd, Cu, and Fe levels were higher than their average oceanic metal concentrations. Moreover, the average concentrations of heavy metals in the studied area, especially those of Pb, Cd, and Zn, were higher than those the coasts of Rosetta, Kazakhstan, Russia, southeast India, and the North Adriatic Sea. The main sources of these pollutants were anthropogenic sources such as gypsum and manganese factories, kaolin deposits, sewage, industrial wastes, urban runoff and irrigation.