title: Heavy metals fractionation and risk assessment in surface sediments of Qarun and Wadi El-Rayan Lakes, Egypt.
abstract: This study establishes a baseline for trace metal speciation in Qarun and Wadi El-Rayan lakes. A five-step sequential extraction procedure was applied for the speciation of the Fe, Mn, Zn, and Cu in sediment samples collected at Qarun and Wadi El-Rayan lakes. Mn and Cu were the most mobile metals, whereas the residue fraction maintained the highest concentrations of Zn and Fe (≈ 60 %). No significant differences in metal concentrations were detected in the sediments of each lake sites, despite of the large distance between them (P > 0.05). Hazardous discharge sources are responsible for the high accumulation of metals in the nonresidual fractions. Qarun Lake showed high mobility factor for all studied metals than Wadi El-Rayan lakes; as such, all the humans, plants, animals and the general biota within the vicinity of this aquatic system are quite vulnerable to the trace metal exposure. According to geoaccumulation index (I-geo), the studied sediments were practically uncontaminated by Fe and Mn and classified as uncontaminated to moderately contaminated with Cu in Qarun and Zn in Wadi El-Rayan lakes. The low values of load pollution index (<1), confirmed the unpolluted condition of the lakes' superficial sediments.
authors.affiliation: Inland Water and Aquaculture Branch, National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt, abdelsatarmena11@yahoo.com.
authors.forename: Amaal Mansour
authors.initials: AM
authors.lastname: Abdel-Satar
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Goher
mesh_terms: D005591:Chemical Fractionation; D004534:Egypt; D004784:Environmental Monitoring / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry*; D060106:Lakes / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical