Abstract
The resistant nature of heavy metals and their toxic effects on living organisms have made them a concern around at the worldwide. In a recent study, a comprehensive assessment of the spatial distribution of heavy metals including cadmium, lead, nickel, copper, zinc and chromium, as well as an assessment of their ecological risks in mangrove and coral sediments from 11 stations located in the Tiab estuary, Larak and Hengam Islands, were performed in the Persian Gulf. Significant spatial variations were observed in heavy metal concentrations. The Tiab area was more polluted than other areas in terms of nickel, copper, zinc and chromium. The Lark region showed the highest concentrations of cadmium and lead metals among the regions. Mean of Contaminant Degree (CD) (11.32), Modified Contaminant Degree (MCD) (1.89), Pollution Loading Index (PLI) (3.11), and Poterntial Ecological Risk Index (PERI) (207.68) in the areas showed that the sediments in these areas are moderately to significantly contaminated with heavy metals, especially cadmium and nickel. Using the Pollution Factor Index (CF) and geo-accumulation index (Igeo), cadmium was identified as the most dangerous metal in the study areas, especially in Lark. Comprehensive and dramatic strategies need to be considered to control and reduce these contaminants, especially in the Lark and Tiab areas to identify and manage the sources of these contaminants.
Keywords: Ecological risk indices, Heavy metals, Spatial distribution, Mangrove and coral regions, Persian Gul