Heavy Metals Concentration (Zinc, Lead, Chrome and Cadmium) in Water and Sediments of Gorgan Gulf and Estuarine Gorganroud River, Iran

The heavy metals include two types of necessary and unnecessary elements which are significant in eco-toxicology. These elements have high stability and can generate toxicity in the organisms. The aim of this study was to measure the heavy metals concentration in water and sediments of Gorgan Gulf، Iran، as a baseline measure for determination of future trends. In the winter of 2010، 30 samples (15 from water and 15 from sediments) were drawn from 5 sampling stations (4 stations in Gorgan Gulf and one station in estuary of Gorganroud River). The samples were measured by atomic absorption spectroscope for concentration of zinc (Zn)، lead (Pb)، chrome (Cr) and cadmium (Cd). The results obtained from the present study showed a significant difference in concentration of heavy metals in water and sediments sampled from various stations. The highest concentration of heavy metals was detected in water and sediments of Gorgan and Gharasou estuaries (stations 1 and 2) and the lowest concentration was found in Galougah seaside and Khozeini canal (the stations 4 and 5). Among the studied metals، Pb and Zn had the highest amount in water and sediments، respectively. Furthermore، when compared to standard limits in water، Cr، Cd، and Pb had more concentration than standard limits of world health organization. The results from metal concentrations in sediments also showed that metal concentration were lower than global standards. Increase of population and pollution can change the amounts of heavy metals in the study areas، hence their measurement should be considered as a continuous and important approach for future studies.