Accumulation and health risk assessment of heavy metals in tissues of the shrimp and fish species from the Yumurtalik coast of Iskenderun Gulf, Turkey.

In this study, concentrations of heavy metals were determined in the tissues of fish species (S. solea and S. aurata) and shrimp (P. semiculatus) from the Yumurtalik zone of the Iskenderun Gulf, Turkey. The aim of of our study is to evaluate potential risks to human health associated with fish and shrimp consumption. Metals concentrations varied significantly depending on the tissues and species. The concentrations of Cu, Fe, Pb and Zn in fish and shrimp tissues were high, while Cd levels were relatively low. In comparing with the permissible limits set by the European Union and Food and Agricultural Organization for fish and shrimp, mean values of Cu, Fe, and Zn were within acceptable limits, but the mean values of Cd and Pb exceeded the limits. From the standpoint of human health, this study suggests that the observed Pb and Cd accumulation may pose a possible health risk to excessive S. solea and P. Semiculatus consumers in Turkey.

Effects of pH on the mortality and accumulation of copper in tissues of Oreochromis niloticus.

In the present study, effect of pH on the mortality and accumulation of copper in various tissue and organs of Oreochromis niloticus were tested at varying concentrations of copper in the medium and over different periods of time. Experimental animals were exposed to pH 5.5, 7.8 and 9.5 and 0.1, 0.5, 1.0 and 5.0 ppm copper over periods of 7, 15 and 30 days in liver, gills and muscle were determined using atomic absorption spectrophotometric techniques. The rate of mortality at 1.0 and 5.0 ppm Cu was 100% after 7 days of exposure at pH 5.5 while at 5.0 ppm Cu was 66% after 30 days of exposure at pH 7.8. No mortality was observed in any of the copper concentrations tested at pH 9.5. In all pH levels, tissue accumulation of copper increased with increasing concentrations of copper in the medium at a given exposure period. In all pH values tested, highest levels of copper were found in the liver of O. niloticus, followed by the gills and muscle tissues. Accumulation of copper in all tissues were higher at pH 5.5 compared with the other pH values in all the conditions tested.