Distributions, Sources and Contamination Assessment of Some Heavy Metals in Intertidal Surface Sediments of Khor-e-Yekshabeh Mangrove Estuary in Persian Gulf

Abstract The water quality of the Persian Gulf is influenced by various industrial and urban discharges. The study area is a small linked estuary with the Straits of Hormuz in the Persian Gulf. This study was conducted to evaluate anthropogenic assessment, pollution status and potential ecological risk of some heavy metals (Pb, Ni, Zn, and Fe) in intertidal surface sediments of a mangrove estuary in the Persian Gulf. Metals concentrations were analyzed using an atomic absorption spectrophotometer. The concentration of metals (all in μg⁄g, except for Fe in %) were as following: 2-9 Pb; 58.9-94.3 Ni; 111.9-185.6 Zn; 1.4- 2.2 Fe. The following contamination indices were also employed: Enrichment Factor (EF), Geoaccumulation Index (Igeo), Pollution Load Index (PLI), effective range low (ERL), and effective range medium (ERM). The results indicated that Zn and Ni were mainly from anthropogenic discharge, while a significant portion of Pb and Fe were likely from natural inputs. Overall, frequent adverse effects were expected for Ni and occasional adverse biological effects were expected for Zn. Likewise, for Pb and Fe rare adverse biological effects were expected. Finally, this baseline contamination assessment study will contribute to establishing interim sediment quality guideline (ISQGs) for Iran.