Mapping heavy metals contamination and eco-risk along Mediterranean Sea coast, Egypt

Abstract

The study was selected according to its variability in resources and its important location parallel to an important protectorate. This coastal zone is characterized by different land use/cover activities (water, industrial site, agricultural areas, bare land, vegetative areas, fish farms, and sabkha). Twelve sites were selected along this part of the Mediterranean deltaic coast, each distance between every site is nearly 5 km. water and sediment samples were collected for the determination of these metal ions (Fe, Mn, Zn, Cu, Ni, Pb, Cd, and Co). The average concentrations of heavy metals are 56.50, 2.53, 24.77, 4.28, 0.88, 18.37, 0.97 and 0.06 µg/l in water and 7284.58, 132.60, 13.52, 2.99, 8.36, 4.84, 0.36 and 4.32 µg/g in sediments for Fe, Mn, Zn, Cu, Ni, Pb, Cd, and Co, respectively. The concentrations of these metals (Zn, Cu, Ni, Pb, and Cd) are within the Australian guideline of marine sediments, but Zn, Cu, and Cd in water exceed these limits. Cadmium was the most abundant element in the coastal marine sediments. The heavy metal pollution index for marine water of the study area is within the normal limits except for site 12. The risk index of metals gives a low-risk category. The principal component analysis indicated that site 11 was related by dissolved Pb in seawater and Fe in sediments, this is maybe interpreted by the nature of sediment texture and different shipping activities. Mapping the spatial distribution of metals and their risk categories is an aid in monitoring environmental problems and quantifying their magnitudes.