ANALYSIS OF SOME HEAVY METALS ACCUMULATION IN WATER, SEDIMENT AND TISSUES OF DIFFERENT FISH SPECIES FROM THE RAZZAZA LAKE, IRAQ

In this study, some heavy metal accumulation were determined in water, sediment and different tissues of three fish species (Cyprinus carpio, Barbus grypus and Ctenopharyngodon idella) collected from Razzaza Lake. Water samples collected from Razzaza Lake were filtered and acidified with 5 ml concentrated nitric acid. Sediment samples and liver, muscle and gill samples were dissolved in the microwave by adding 1 ml of concentrated perchloric acid and 7 ml of concentrated nitric acid. Heavy metal levels in water, sediment and fish tissue samples were measured with ICP-MS instrument. Hg was not detected in lake water, sediment and fish tissues. Cd was not detected only in lake water. Among the metals, the highest concentrations in water, sediment and tissue samples were found for Al. The heavy metal levels detected in the Razzaza Lake water were below the permissible levels of heavy metals in the aquatic environment. According to Sedimanter quality guidelines, the Razzaza Lake sediment had the lowest effective concentration for As, Cu, Pb, Hg and Zn, high effective concentration for Cd and Ni. In the Razzaza Lake, heavy metal accumulation order has been identified as sediment> fish (liver> gill> muscle tissue)> lake water. Pb levels in all tissues and Ni levels in the gills of Ctenopharyngodon idella were above the permissible levels recommended by FAO and Turkish legislation. The present study shows that the metals level in muscle of Cyprinus carpio and Barbus grypus species did not exceed permissible levels recommended by FAO and Turkish legislation and these fish are considered safe for human consumption. But, the consumption of Ctenopharyngodon idella which is exposed to more heavy metals due to high consumption of grass should be restricted for human health.