Bioaccumulation of Total and Organic Mercury in Goldfish (Carassius auratus gibelio) in Anzali Wetland, and Assessment of Health Risks

Background and Mercury contamination is still a threat to the environmental and public health in both developed and developing countries. The aim of this study was to determine the total and organic mercury content in the muscle of goldfish (Carassius aurathus gibelio) obtained from the east and west of Anzali Wetland. We also assessed the health risks involved in consumption of this fish. Twenty goldfish were collected from the east and west of Anzali Wetland. Total mercury concentrations were determined using Advanced Mercury Analyzer (AMA 254), and organic mercury concentrations in the muscle were also determined by AMA 254 following acid digestion and extraction with toluene. Total mercury and organic mercury concentrations in the muscles tissue of goldfish collected from the east of Anzali wetland were significantly higher (106.97±56.92 ng/g ww and 88.00±45.41 ng/g ww) than those obtained from west of the wetland (45.50±16.88 ng/g ww and 40.62±14.32 ng/g ww). Also, significant positive correlations were found between concentrations of total and organic mercury and the amount of lipid. The mean concentrations of total mercury in all fish samples did not exceed the maximum level recommended by the World Health Organization for human consumption (0.5 mg g-1 ww). However, the maximum number of allowable consumption of fish per month in east and west of the wetland for children were found 3 and 5, respectively and for adults these allowable numbers were 13 and 25, respectively.