Ecological Risk Assessment of Heavy Metals in the Marine Area Sediments of Shahid Bahonar Port of Bandar Abbas

Monitoring the concentration of heavy metals in marine sediments is very important for identifying existing and potential risks and developing prevention programs. In the present study, considering the various unloading, loading and shipping activities in Shahid Bahonar Port, the concentration of heavy metals including chromium(Cr), zinc(Zn), copper(Cu), nickel(Ni), mercury(Hg), arsenic(As), manganese(Mn), cobalt(Co), iron(Fe) and cadmium(Cd) in the eleven stations of marine area of the port was measured by atomic absorption method. The Muller's indices (Igeo), contamination factor (CF), contamination degree index (Cd), modified contamination degree index (mCd) and RI ecological risk assessment index was calculated. The average value of metal concentration was compared with NOAA and ISQGs international sediment quality standards as well.The findings showed that the highest concentration of heavy metals was related to iron > manganese > zinc > chromium > nickel > copper > cobalt > arsenic > cadmium > mercury respectively. The average value of heavy metals concentration measured in the sediments in terms of milligrams per kilogram was calculated as arsenic (3.4), cadmium (1.2), iron (22261.4), copper (61.64), zinc (116.3), manganese (333.79), mercury (0.23), cobalt (26.29), chromium (177.92) and nickel (90.96) ) respectively. The results of ecological risk indices show that heavy metals contamination is moderate or considerable in most of the studied stations and the stations inside the port basin have a higher cumulative risk than those outside the port.According to the obtained results, it can be said that the port activities, the discharge of the balance water of the ships, as well as the closure of the port basin and the low ratio of water exchange to the outside of the basin are factors that cause settlement and accumulation of heavy metals in the sediments