Contamination and ecological risk assessment of trace elements in sediments of the Anzali Wetland, Northern Iran

Abstract

In this paper, concentrations of some heavy metals in surficial sediments of the International Anzali Wetland were measured, this wetland is located in the northern part of Iran. Sediment pollution levels were examined and analyzed using reliable pollution indices including Pollution Load Index (PLI), Geoaccumulation Index (Igeo) and Enrichment Factor (CF), and finally it was revealed that heavy metal pollution ranged from low to moderate loads in the wetland. According to Sediment Quality Guidelines (SQGs) and Ecological Risk Index (ERI), it was concluded that As and Ni may have significant toxic impacts on aquatic organisms and also according to Effect Range Median (ERM), the toxicity probability of sediments in the Anzali wetland was estimated at 21%. HIGHLIGHTS Metal pollutions in aquatic ecosystems have raised worries worldwide.; Anzali Wetland is one of the most important aquatic ecosystems in Iran and is threatened by different kinds of contaminants such as metals.; Sediment pollution analysis is one of the proper approaches to investigate metal in the aquatic environments.; Ecological risk assessment with this method has been done for the first time in Anzali.;

Keywords

• international anzali wetland
• pollution level indices
• risk assessment
• sediment quality guidelines