Study on some heavy metals contamination and risk assessment in muscle tissue of Rutilus frisii kutum and Liza saliens of Caspian Sea

Recently, the ecology of the Caspian Sea has undergone with increasing development of human activities and industrial wastewater discharges. Heavy metal compounds are undegredable pollutants and are able to accumulate in the environment. They can affect the food chain and biological individuals such as fish species. 40 and 22 samples of Rutilus frisii kutum and Liza saliens were collected in central and eastern parts of southern Caspian Sea in 2008, respectively. All samples were analyzed based on standard methods using Atomic Absorption instrument (Thermo, M5 model). Results of this study showed that the amount of Zn in fish muscle of L. saliens was maximum (415.3±196.3 µg/g. dw). The concentrations of Cu, Ni, Pb, Cd and Hg in fish muscle of L. saliens were 10.85 ±11.02, 0.41 ±0.84, 2.63 ±2.67, 0.63 ±1.07 and 1.30 ±0.16 µg/g. dw, respectively. The concentrations of Cu, Ni, Pb, Cd and Hg in fish muscle of R. frisii kutum were 0.40 ±0.46, 0.0132 ±0.007 and 1.26 ±0.75 µg/g. dw, respectively. 7 heavy metals were below the established limits of different countries. The pearson correlation analysis showed that between Zn and Hg there were a significant negative correlation indicating a decrease of Hg toxcicity with increasing Zn concentration. THQs for individual metals were lower than USEPA guidelines value of 1 in young and adults human. Thus, consumption of 6 kg R. frisii kutum and/or L. saliens per capita cannot be risky for young and adults consumers.