بررسی فلزات سنگین کادمیوم، سرب، مس و روی در بافت عضله اردک ماهی تالاب بین‌المللی انزلی، انباشتگی و ارزیابی خطرات

Background and purpose: The pollution of aquatic ecosystems with heavy metals, have always been a major concern for aquatic organisms and human health. Contaminants such as heavy metals are accumulated along the food chain and then transmitted to human body. Levels of contaminants in fish are of particular interest because of the potential risk to humans. This study examined the levels of cadmium, lead, zinc and copper in muscle tissue of Esox lucius from the Anzali international wetland and then compared them with the standards established for human health. Materials and methods: This research was done on 26 Pike perch (Esox lucius) obtained from Anzali wetland by multimesh gill nets in September 2010. The samples were digested by concentrated nitric acid, and then were analyzed for Pb in a graphite furnace atomic absorption spectrophotometer and for Cd, Cu, and Zn in a flame atomic absorption spectrophotometer. Results: Mean concentration of Cd, Pb, Cu and Zn was 0.82 ± 0.06, 0.22 ± 0.02, 5.68 ± 0.31, 54.26 ± 0.87 (µg/g dry weight), respectively. The results showed no significant correlation between Pb, Cu and Zn concentrations with body weight and length but a significant negative correlation was observed between Cd concentration with body length (r= -0.88, P<0.05) and body weight (r= -0.9, P<0.05). Conclusion: The levels of Zn, Cu and Pb were lower than the standard levels established by WHO, FAO, and EPA but levels of Cd exceeded the standards of WHO and EPA. These results can be a warning for consumers of these fish. According to the daily intake of heavy metals consuming this fish on weekly basis is not prohibited.