Heavy Metal Pollution Assessment in Sediment of Mussel Habitats UsingGeochemical Indices

Abstract

The heavy metals Pb, Cd, Cu, Zn, and Ni were analyzed in the soft tissue of mussels (Anodonta cygnea) as well as in sediments at five regions of Anzali Wetland, on the southern bank of the Caspian Sea during October and November 2016. The data were applied for assessing the pollution levels in emphasizing the mussel habitats by geochemical indices and furthermore answering the inquiry whether these indices can predict the contaminant level in the swan mussel soft tissue. The highest geochemical indices in the sediment: EF, Igeo, CF, and PLI revealed moderately to seriously contamination level of Cd and Pb in sampling sites. The sheijan and Bahambar also showed a higher contamination level of metals than in other regions. According to the ecological risk index (RI) Mahrouzeh, Hendekhaleh, Abkenar, and Bahambar areas were presented within the range of moderate risk level. Additionally, multivariate statistics showed that Ni is controlled by parent rocks and at the same time Pb, Cd, Cu, and Zn originated from anthropogenic sources. The highest geochemical data for Pb, Cd, Cu, Zn, and Ni recorded in Bahambar, Abkenar, Mahrouzeh, Sheijan, and Mahrouzeh respectively. But the highest accumulation of Pb, Cd, and Cu in mussel measured in Bahambar, Abkenar, and Mahrouzeh respectively, and also Zn and Ni in Hendekhaleh. Therefore, the geochemical index data does not always predict heavy metal contaminants into the soft tissue of mussels in sampling sites.