1615 Research Article Received: 24 October 2008 Revised: 10 April 2009 Accepted: 20 April 2009 Published online in Wiley Interscience: 22 May 2009 (www.interscience.wiley.com) DOI 10.1002/jsfa.3646 Essential elements and contaminants in tissues of commercial pelagic fish from the Eastern Mediterranean Sea Beyza Ersoy a* and Mehmet C ¸ elik b Abstract BACKGROUND: It is important to determine the concentrations of essential and non-essential metals in fish for human health. The essential elements and contaminants (Pb and Cd) were determined seasonally in the muscle and liver of some pelagic fish species round herring (Etrumeus teres), chub mackerel (Scomber japonicus), golden grey mullet (Liza aurata) and Mediterranean horse mackerel (Trachurus mediterraneus) from the Iskenderun Bay, Eastern Mediterranean Sea. RESULTS: The Na, K, Ca and Mg were the most abundant elements in muscle and liver tissues. The Na, K, Ca and Mg concentrations in fish tissues were between 51.7 and 3426 mg kg -1 . Muscle accumulated the lowest levels of elements. Trace element and contaminant levels in muscle were highest in spring and summer. The Cu, Zn and Cr concentrations were highest in summer. The Ni, Mn and Fe concentrations were highest in spring. The maximum Pb concentrations in the muscle and liver of fish species was 0.39 and 0.80 mg kg -1 in autumn. The maximum Cd concentration in the muscle of fish was 0.27 mg kg -1 in spring and the maximum Cd concentration in the liver was 0.78 mg kg -1 in summer. CONCLUSION: The Cr, Pb, Cd, Cu and Zn levels in muscle were found to be lower than permissible limits reported by various authorities. Estimated weekly and daily intake for Pb and Cd by consumption of fish muscle were far below the PTWI and PTDI values established by FAO/WHO. c  2009 Society of Chemical Industry Keywords: Eastern Mediterranean Sea; fish; essential elements; contaminants; risk evaluation INTRODUCTION Utilisation of marine resources for human consumption has in- creased rapidly worldwide. In 2004, about 75% (105.6 million tones) of estimated world fish production was used for direct human consumption. 1 Seafood is rich in protein, contains low cholesterol and high percentage of n-3 polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), liposoluble vitamins and essential minerals. 2–5 In the last few years, the health benefits associated with seafood have been studied extensively. 6–14 The American Heart Association, 10 American Dietetic Association 15 and the US Dietary Guidelines Ad- visory Committee 16 all recommend two servings of fish per week. Seafood is a good source of many essential elements. Many elements, which are present in seafood, are essential for human life at low concentrations although essential elements can be toxic at high concentrations. In recent years, attention has been focused on determination of elements in seafood due to nutritional benefits of essential elements and toxicological concerns related to anthropogenic influx of contaminants. Lack of essential elements (such as Na, Mg, Cl, P, S, K, Ca, Mn, Fe, Cu, Zn, Se) leads to improper enzyme-mediated metabolic functions and results in organ malfunctions, chronic diseases and ultimately death. 17 Therefore, regular intake of these elements via food ingestion is vital. From the toxicological point of view, the environmental contaminants such as mercury (Hg), cadmium (Cd), arsenic (As) and lead (Pb) are non-essential metals. Non-essential metals are not known to play any metabolic function and can be toxic for humans, even at very low concentrations. 18 They may occur naturally in the environment or be released by human activities. 19–21 Toxic metals can be assimilated, stored and concentrated by organisms through the food chain. 22,23 Accumulation patterns of contaminants in fish and other aquatic organisms depend both on uptake and elimination rates. 24,25 Different tissues of the fishes show significant difference for metal accumulation. Normally, the kidney and liver showed higher enrichment coefficients than gill, muscle and swim bladder. 26,27 Regarding these toxic metal ions, most of the chemical reactions that explain their toxicity at cellular level, involve electronic transference, formation of free radicals and their influence on the DNA chain, with possible consequences in mutagenicity, genotoxicity and carcinogenicity phenomena, as well as competition reactions with essential elements. 28 Long- term high cadmium exposure may cause kidney and skeletal ∗ Correspondence to: Beyza Ersoy, Department of Fishing and Fish Processing Technology, Faculty of Fisheries, University of Mustafa Kemal, 31200 Hatay, Turkey. E-mail: beyzaersoy@hotmail.com a Department of Fishing and Fish Processing Technology, Faculty of Fisheries, University of Mustafa Kemal, 31200 Hatay, Turkey b Department of Fishing and Fish Processing Technology, Faculty of Fisheries, University of C ¸ukurova, 01330 Adana, Turkey J Sci Food Agric 2009; 89: 1615–1621 www.soci.org c  2009 Society of Chemical Industry