Mercury is the most toxic heavy metal in the aquatic ecosystems which originates both from natural and industrial resources and is ultimately deposited in sediments as methyl mercury. This metal is quickly transferred through the food chain and accumulated in organisms. In this study, the human health risk due to consumption of Mullet (Liza aurata) in the Caspian Sea, were evaluated by measuring the concentration of mercury in muscle samples using Atomic absorbtion spectrophotometer (Perkin Elmer FIAS-100) and cold vapor technique. A total of 60 fresh Mullet samples were collected by local fisherman from 12 stations on the southern coast of Caspian Sea in Mazandaran province situated in the north of Iran. The average concentration of mercury in Mullet muscle was 0.137 µg/g of fresh weight (0.432 µg/g dry weight) which was less than the allowable amount for human consumption determined by the international organizations such as United States Environmental Protection Agency, World Health Organization, Food and Agriculture Organizations and the Food and Drug Administration. The calculations indicated that daily and weekly mercury uptake for Iranian consumers is lower than the guide values (Acceptable Daily Intake and Provisional Tolerable Weekly Intake) provided by international organizations. Also, Hazard Quotient Index was below 1 (0.35). Therefore, the consumption of the Mullet is not a serious threat to the consumer’s health and a consumption permitted rate of 51 g per day is recommended
