The present study was designed to compare the responses in freshwater fish Oreochromis niloticus exposed to a synthetic pyrethroid, cypermethrin (CYP); an essential metal, copper (Cu); and a nonessential metal, lead (Pb). Fish were exposed to 0.05 μg/l CYP, 0.05 mg/l Cu, and 0.05 mg/l Pb for 4 and 21 days, and the alterations in serum enzyme activities, metabolite, and ion levels were determined. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased in response to CYP, Cu, and Pb exposures at both exposure periods. While elevations in alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities and in cholesterol level were observed in pesticide-exposed fish at 4 and 21 days, they increased in Cu- and Pb-exposed fish at 21 days. Although metal-exposed fish showed increases in cortisol and glucose levels at 4 days followed by a return to control levels at the end of the exposure period, their levels elevated in pesticide-exposed fish at both exposure periods. Total protein levels decreased in Pb- and pesticide-exposed fish at 21 days. Na+ and Cl− levels decreased in pesticide-exposed fish at both exposure periods and in Cu- and Pb-exposed fish at 21 days. The exposures of pesticide and metals caused an elevation in K+ level at the end of the exposure period. The present study showed that observed alterations in all serum biochemical parameters of fish-treated pesticide were higher than those in fish exposed to metals.

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 Yumurtalık 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.

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Copper, chromium cadmium, iron and zinc concentrations were determined in marine crab Charybdis longicollis and marine shrimp Penaeus semisulcatus in order to assess the impact of industrial activities and the sinking of M/V Ulla ship. Liver, gill and muscle sample solutions prepared analyzed using the atomic absorption spectrophotometry technique. The order of the metal concentrations found in muscle of crab was: Cu>Cr>Fe>Zn>Cd, while in muscle of shrimp the order was different: Cr>Cu>Zn>Fe>Cd. The highest Cu, Cr, Cd, Fe and Zn concentrations were found in the liver, and this was followed by the gill and muscle in both species. The levels of all metals in a given tissue were always higher in C. longicollis than in P. semisulcatus. Metals in both species show seasonal variations. In both species the highest concentrations were detected for all metals in summer.

In this study, we analyzed the effects of cadmium (1.25, 2.5, 5, 10, 20, and 40 mg per 100 g of nutrient) on total protein, lipid, and glycogen levels, lipid peroxidation (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, and metal accumulation in Galleria mellonella L. High concentrations of Cd (20 and 40 mg) significantly lowered total protein, lipid, and glycogen levels. MDA level significantly increased when the nutrient contained 5 mg and more of Cd, whereas SOD activity significantly increased at Cd concentrations starting from 1.25 mg. CAT activity significantly decreased at all concentrations. Metal accumulation also significantly increased in a dose-dependent manner. These changes observed on activity of antioxidant enzymes, energy reserves, MDA content, and accumulation levels of Cd can be used as a reliable biomarker of environmental heavy metal pollution in model insect G. mellonella.

We investigated the effects of Zn, Cd and a Zn + Cd mixture on antioxidant parameters and metal accumulation in Oreochromis niloticus. Fish were exposed to 0.5 and 5.0 mg l(-1) Zn, 0.1 and 1.0 mg l(-1) Cd, and 0.5 mg l(-1) Zn + 0.1 mg l(-1) Cd and 5.0 mg l(-1) Zn + 1.0 mg l(-1) Cd mixtures for 7 and 28 days to determine Zn and Cd accumulation, reduced glutathione (GSH) level and glucose-6-phosphate dehydrogenase (G6PD) activity in gill and liver. There was increasing accumulation of the metals in the tissues with increasing concentrations of metals in the exposure medium and with increasing duration of exposure (except at the lower concentration of Zn). Concentration of metals in the tissues of fish exposed to the Zn + Cd combination were significantly lower than in fish exposed to the single metal. The highest metal accumulation was observed in the liver. Exposure to the heavy metals affected the antioxidant parameters in the tissues, with both GSH level and G6PD activity in the gill and liver being increased under Zn, Cd and Zn + Cd exposures, especially in their higher concentrations. These increases in the antioxidant responses were higher with the Cd alone, and in combination with Zn, than with Zn alone. Furthermore, GSH level and G6PD activity increased with increasing exposure period only for Cd alone, and in Cd combination with Zn. The results indicate that O. niloticus resisted oxidative stress induced by heavy metal exposure by antioxidant mechanisms.

Samples of Mugil cephalus and Mullus barbatus were collected in the Northeast Mediterranean coast of Turkey the contents of cadmium, copper, iron, zinc and lead in the liver, gill and muscle tissues were determined by atomic absorption flame spectrophotometry. Except for lead, highest levels of each metal were found in the liver and this was followed by the gill and muscle in both species. Among the metals analyzed, Cu, Zn and Fe were the most abundant in the different tissues while Cd and Pb were the least abundant both in M. cephalus and M. barbatus. Seasonal changes in metal (Cd, Cu, Pb, Fe and Zn) concentration were observed in the tissues of both species, but these seasonal variations may not influence consumption advisories. In general, the highest concentrations were detected for all metals in summer.

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