Fractionation, chemometric analysis, and sophisticated risk assessment indices to appraise sediment contamination of a tropical mangrove forests, the Red Sea

This paper adds a new perspective to Ras Mohamed Protectorate mangrove sediment quality studies in terms of bioavailability, mobility, human and eco-environmental risk of various potential toxic elements (PTEs). Fe > Mn > Pb > Cu > Cd was the order in which the PTE levels declined. Residual fraction controlled the geochemical speciation of all elements. The following was the order of the mean percentages of mobile elements in sediments: Mn > Fe > Pb > Cu > Cd. All sediment samples had low to moderate risk, according to synergistic indices (GCF, mRAC, PETI-A and PTEI-B). Mn was the primary ecological risk PTE contributor. According to the suggested individual indices, Mn is the most mobile and bioavailable element (0.4–1), whereas Cd, Cu, Fe, and Pb have moderate mobility and bioavailability (MI 0.1–0.4 and BI 0.1–0.4, respectively). The current PTE exposure in sediments did not constitute a significant health concern (THQ < 1 and LCR < 10⁻⁴).