Determination of heavy metals concentration in muscle tissue of Cryfish (Astacus leptodactylus)

: Heavy metals are chemical pollutants characterized by their toxicity, stability, bioaccumulation and biomagnification. They might accumulate in aquatic organisms, transfer through food chain and enter into human body. Therefore, the study of their accumulation in the edible aquatic species has been a very important part of ecological and monitoring investigations. Astacus leptodactylus is a benthic species, which is sedentary and omnivores, and is recently becoming one of the food sources in Iran. Samples were randomly purchased from the Tehran market. Their length, weight and sex were determined. The concentrations of lead, chromium, copper and zinc in muscle tissues were obtained using wet digestion and atomic absorption spectroscopy (Perkin Elmer, USA). Results were analyzed using the statistical software SPSS 19. No correlation was found between weight and length with the metal concentrations. There was also no correlation between sex and the concentration of toxic elements; however sex found to have significant correlation with the concentration of essential elements. There was significant differences between concentration of metal; and the pattern of accumulation of the metals was Zn > Cu > Cr ≥ Pb. Comparison of the metal concentrations with standard values indicated that copper and zinc concentrations are lower than concentrations allowed by WHO ​​and ANHMRC, while lead concentration was around the allowed levels. Because of very low consumption of this aquatic organism in Iran and a decrease observed in the concentrations of toxic metals after cooking, the consumption of this seafood is not harmful to human health. However, it is necessary to take safety precautions, so that the concentrations of the metals do not increase in aquatic ecosystems and in turn in seafood.