Risk assessment of mercury and lead in fish species from Iranian international wetlands

The aim of this study is determination of mercury concentration in the muscle, intestine, gonad and kidney of Rutilus rutilus, Hemiculter Leucisculus (Anzali wetland), and Alosa Caspia Caspia (Caspian Sea), and mercury and lead concentrations in the muscle of Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Schizocypris altidorsalis, and Schizothorax zardunyi (Hamun wetlands). The results of this study were compared with global standards. As well as in this multispecies monitoring, health risk assessment of consumers by EPA/WHO instructions has been done. The concentrations of mercury were below the limits for fish proposed by United Nations Food and Agriculture Organization (FAO), World Health Organization (WHO), US Food and Drug Administration (FDA) and US Environmental Protection Agency (EPA), and European Union (EU). Lead concentrations in Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix was under the scope proposed by FAO, WHO, FDA, Turkish Acceptable Limits (TAL), United Kingdom Ministry of Agriculture Fisheries and Food (UK MAFF) and National Health and Medical Research Council (NHMRS), but lead concentration in Schizocypris altidorsalis, and Schizothorax zardunyi were higher than WHO and TAL. Health risk assessment of consumers from the intake of metal contaminated (mercury and lead) was evaluated by using Hazard Quotient (HQ) calculations. The human health hazard Quotient (index) showed that the cumulative risk greatly increases with increasing fish consumption rate, thus yielding an alarming concern for the consumer’s health. • The results of the present study aimed to provide data from Caspian Sea, Anzali wetland, and Hamoon wetland as indicators of natural and anthropogenic impacts on aquatic ecosystem as well as to evaluate the human hazard index associated with fish consumption. • The results show that for mercury, the Maximum Allowable Fish Consumption Rate (Meals/Month) is related to Hemiculter Leucisculus. • The results for lead concentration indicate that there is no HQ value > 1, indicating that humans would not experience any significant health risk if they only consume metals from these species of fish from the hamun wetland. Keywords: Risk assessment, Heavy metals, Anzali wetland, Caspian Sea, Hamun wetland