Aktuelle Ernährungsmedizin 2013; 38 - PP44
DOI: 10.1055/s-0033-1343717

Determination of selected heavy metals in tuna fish (Thunnus thynnus)

S Mol 1, S Karakulak 2, S Ulusoy 1
  • 1Seafood processing and quality control, Istanbul University, Faculty of Fisheries, Istanbul
  • 2Fisheries Technology, Istanbul University, Faculty of Fisheries, Istanbul, Turkey

Introduction: Heavy metals of tuna fish (79 individuals) were determined. The variations (mg/kg) were 0.258 – 4.548 for Cu; 3.997 – 18.29 for Zn; ND(Not determined)- 0.012 for Cd; 0.164 – 2.396 for Hg and ND(Not determined)-0.912 for Pb. Mercury contents of 2, and Pb of 6 individuals were above the limits.

Objectives: Determining cancer risk of tuna, regarding heavy metals; and providing information for surveillance programs were the objectives.

Methods: The 79 individuals of tuna (Thunnus thynnus) from the Eastern Mediterranean Sea, were analyzed regarding Cu, Zn, Cd, Hg, Pb using ICP-MS.

Results: For fish, 20 mg/kg Cu is the limit (1,2). The maximum Cu content was 4.548 mg/kg, which is well below the permissible limit.

The presence of Zn was limited as 50 mg/kg (1,2). The highest Zn concentration was 18.29 mg/kg in our samples, below the limit of 50 mg/kg (1,2).

The maximum Cd content was 0.012 mg/kg and all samples were acceptable, since the limit is 0.1 mg/kg for tuna (2,3).

As to Hg, 2 individuals contained this metal above the limit, 1 mg/kg (2,3,4).

In this study, the variations of Pb was ND (Not determined) – 0.912. Of the 79 individuals 6 contained this metal above the permissible limit, proposed as 0.4 mg/kg for tuna (2).

Conclusion: Regarding the Cu, Zn, and Cd contents, the samples were safe for human consumption. However, some samples recorded higher concentrations of Hg and Pb than the acceptable values. This result underlines the significance of periodical controls of tuna fish with respect to toxic elements.

References:

[1] CEFAS (1997): Monitoring and surveillance of non-radioactive contaminants in the aquatic environment and activities regulating the disposal of wastes at sea, 1994. Aquatic Environment Monitoring Report No. 47 Lowestoft.

[2] TURKISH FOOD CODEX (2002): Su Urunleri Yonetmeligi, Offcial Gazette, 9, No. 24936, Ankara, Turkey.

[3] EU (2006): Commission Regulation, Setting Maximum Levels for Certain Contaminants in Foodstuffs. (EC) No 1881/2006 Official Journal of the European Union.

[4] FDA (2011): Fish and Fishery Products Hazards and Controls Guidance IFAS, Gainesville, Florida.

Disclosure of Interest: None Declared