Determination and investigation of heavy metal concentrations in sediments of the Persian Gulf coasts and evaluation of their potential environmental risk

The contamination of coastal sediments with toxic heavy metals caused to a serious concern due to their environmental consequences. The aim of this study was to determine the concentration of heavy metals such as lead (Pb), copper (Cu), nickel(Ni) and manganese (Mn) in the sediments of the Persian Gulf coast in Kangan and Siraf ports in Bushehr province. In this regard, the sampling was performed in ۱۰ stations with different uses in two depths of ۰-۵ and ۵-۲۰ cm along the coast of the Persian Gulf. The concentration of heavy metals was measured after drying, acid digestion and microwave by using flame atomic absorption spectrometry (F-AAS). Ecological risk index was used to assess the potential of environmental risk due to heavy metal pollution in the coastal sediments of the study area and the sensitivity of the biological community to toxic substances. Then statistical analysis in SPSS environment was used for analyzing the data. The results showed that the average concentrations of Mn(II), Ni(II), Cu(II) and Pb(II) was measured ۱۲۱.۴۷, ۱۱.۵۱, ۱۱.۵۹ and ۵.۳۰ in surface sediments, and ۱۳۱.۵۹, ۱۰.۸۱, ۱۲.۵۶ and ۴.۸۸ μg g-۱ in deep sediments. The results of the ecological risk index with the value of less than ۱۵۰, showed a low environmental risk of heavy metals detected in the region. Also, the results of multivariate statistical analyzes indicated the existence of a correlation and common origin of Cu, Ni and Mn. In general, this study led to a better understanding of the contamination of heavy metals in the region and considered it necessary to try to prevent, control and reduce the amount of pollution in the sediments of the Persian Gulf coast. All analysis validated by electrothermal atomic absorption spectrometry(ET-AAS) after dilution samples with DW.