Background and Aim: The concentration of heavy metals in aquatic ecosystems is assessed in water, sediments, and living organisms. Typically, heavy metals are found in the lowest concentrations in water, with significant accumulation occurring in sediments, followed by increased levels of bioaccumulation in living organisms. This study aims to measure the concentrations of heavy metals -chromium (Cr), nickel (Ni), zinc (Zn), copper (Cu), arsenic (As), iron (Fe), lead (Pb), and cadmium (Cd)- in the sediments of Khor Jask and Yek Shabah Hormozgan Province.
Methods: To identify environmental pollution caused by heavy metals, sample locations were first determined using GPS. Surface sediment samples were collected using a grab sampler, with 30 samples taken from Jask (both intertidal and subtidal zones) and 30 samples from the Yek Shabah. After drying and acid digestion, a flame atomic absorption spectrometer was employed to determine the concentration of heavy metals, followed by the calculation of the enrichment index.
Results: The results indicated significant differences in the average concentrations of the studied elements across different stations (P<0.05). In the sediments of the Jask estuary, the highest average concentration was found for chromium at 59±45.73 µg/g, while the lowest was for cadmium at 0.14±0.04 µg/g. In contrast, the Yek Shabah estuary sediments exhibited an average concentration of 101.33±5.03 µg/g for nickel and 0.16±0.01 µg/g for cadmium. According to the Mueller geochemical index, the sediments in the studied areas were classified as unpolluted to slightly polluted.
Conclusion: Overall, the findings suggest that the sediments of the Yek Shabah estuary fall within the category of low to moderate pollution, while the Jask estuary is either free from pollution or exhibits low levels of metal pollution in Hormozgan Province. In terms of enrichment factors, all studied elements -except arsenic- showed minimal enrichment. The Yek Shabah estuary displayed very high enrichment for arsenic, whereas the Jask estuary demonstrated minimal enrichment.
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