منشأیابی و پراکنش فلزات سرب، مس، روی، نیکل، کروم و وانادیم در رسوبات سطحی سواحل دریای خزر

Background and purpose: This study aimed to determine the origin and distribution of lead, copper, zinc, nickel, chromium and vanadium in surface sediments of Mazandaran coastline (southeastern coast of the Caspian Sea). Materials and methods: Surface sediment samples were collected from four transects in Tonekabon, Noshahr, Babolsar and Amir abad port, at three different depths of 5, 15 and 30 m in July 2012. Metals concentration were determined by ICP - OES. Results: The metals in the studied areas were found to be from natural sources, probably due to weathering of rock and soils erosion transported by rivers into the sea. Significant difference was seen in the mean total concentration of metals along the four transect when the distance from the shore increased. The mean concentration of metals along the coast from east to west showed a significant increase. Among the metals, the highest concentrations was found for zinc (104 μg/g) at 30 m depth in Babolsar transect and the lowest concentration was found for copper (8.72 μg/g) at 5 m depth in Amir abad port transect. Conclusion: Total concentrations of metals were lower than standard levels (SQGs and NOAA). Moreover, the risk assessment code (the presence of metals in the exchangeable fraction) did not show any risk from copper, zinc, nickel, chromium and vanadium, but it showed only a low risk for lead. This study found that the studied metals have low-risk for local environment.