Multivariate statistical assessment of heavy metal contamination in muscle of Silurus glanis L., 1758 from Kılıçkaya Reservoir in Turkey

Heavy metals entering aquatic ecosystems from natural and anthropogenic sources are a significant water pollution problem. They accumulate in organisms living in aquatic ecosystems, and threaten human health by entering food chains. This study was carried out to assess the Cd, Cr, Cu, Mn, Ni, Pb and Zn contamination concentrations with multivariate statistical analysis in muscle tissue of the European catfish (Silurus glanis L., 1758) caught from Kılıçkaya Reservoir. The target tissue where heavy metals are stored and the muscle tissue, as it is the most edible part of the fish, were used in this paper. Contamination concentrations of heavy metals expressed in μg g^-1 were determined with an atomic absorption spectrophotometer. As a result, maximum values of heavy metal concentrations in muscle tissue of Silurus glanis samples were measured at 0.03 μg g^-1 for Cd, 0.37 μg g^-1 for Cr, 3.59 μg g^-1 for Cu, 3.32 μg g^-1 for Mn, 0.68 μg g^-1 for Ni, 0.43 μg g^-1 for Pb and 23.15 μg g^-1 for Zn. The correlation between Zn, Cd, Cr, Mn and Cu concentrations was very strong and significantly positive (r=0.818**, r=0.931**). Principal component analysis revealed two components explaining 94.50% of the total variance. The first component is dominated by Cu, Mn and Cd, while the second component is dominated by Ni and Zn. It is thought that the metals that dominate the first and second components are generally accumulated due to environmental factors and partially due to the geological structure of the region. According to the hierarchical clustering analysis results, 2 different groups were distinguished. The first group includes Cr, Pb, Ni, Cd, Cu and Mn, while the second group contains only Zn. Concentrations of Cd, Cr, Cu, Mn, Ni and Zn were below the FAO and EU recommended limits for fish, while Pb was found above the EU recommended limit. In this case, it poses a risk in terms of food safety and human health. Hence, it will be very beneficial to take the necessary measures immediately.