Study of heavy metals concentration Cd, Cr, Pb and Ni, in cultured ponds fishes of Khorramabad city in 2006

The consumption of aquatic nutrition sources, especially fishes, considered as a partial supply of protein, for ever-increasing demand of protein. According to statistics, the annual consumption of aquatic sources per capita in the word increased from14. 3Kg in the year1994 to more than 15. 75 Kg in 1997 and in Iran it increased from less than 1 kg in the year 1978 to 4.57 kg in the year 1996. So an ever-increasing demand of protein sources of the food and bioaccumulation of toxic compound especially toxic heavy metals increase safety control importance of the food. In this descriptive cross-sectional study heavy metals concentration Cd, Cr, Pb and Ni in cultured ponds fishes of Khorramabad city were studied in 2006. To evaluate the safety of the cultured ponds fishes in khorramabad city from toxic heavy metals Cd, Cr, Ni and Pb, 240 samples of fishes were collected. The fishes were collected in the Spring and Summer seasons in 2006. The samples washed and digested with acid before using Atomic Absorption for determination of the metals, then data were analyzed using t-test and SPSS software. The results of the study showed that the average value of Lead, Chromium, Cadmium and Nickel in ten cultured ponds fishes tissue were 0. 46, 0. 06, 0. 053 and 0. 30 ppm (dry weight basis) respectively The study also showed that the amounts of Pb in 27%, Cd in 8%, Cr in 3% and Ni in 25% of the samples exceeded the WHO standard limits while the averages were blow the standard. The statistical analysis of the samples showed that there are not significant differences between the different species of the fishes for all the heavy metals, except the fishes collected from the cultured ponds. Higher amount of the heavy metals in sea fishes could be related to fish food, which could bioaccumulated in fish tissues. The study revealed that non of the heavy metals collected in the fish samples exceeded the WHO standards.