Assessment of toxic elements' content in swine kidneys: Pathomorphological analysis

Background: In order to ensure the safety of consumers in Serbia, the toxic elements' (Cd, Hg, As, Pb) content in swine kidneys collected from three different sites in Serbia (n=90), were determined by atomic absorption spectrometry. Also, in order to find information on the effects of accumulation of toxic elements in swine kidneys, histopathological examination of kidneys was carried out. Methods: Determination of toxic elements (Cd, Hg, As, Pb) in swine kidneys was performed by atomic absorption spectrometry. For microscopic examination, kidney samples were fixed in 10% neutral buffered formalin and absolute alcohol for 5 to 7 days, processed by routine methods, sectioned at 5-8 μm, and stained with hematoxylin and eosin (HE) for light microscopy. Results: The presence of mercury was found in 33.3% of kidney samples in the range of 0.005-0.055 mg/kg, while presence of cadmium was found in less degree (27.7%) but in higher content (0.05-1,23 mg/kg). The presence of arsenic was found only in one sample, while presence of lead was not found. The metal-to-metal correlation analysis supported the theory that there were different sources of contamination. Histopathological examination of kidneys confirms tubulopathies with edema and cell vacuolization. In addition, hemorrhages and necrosis of proximal kidney tubules' cells were found. Conclusion: This study shows the presence of toxic elements in pigs butchered in Serbia at levels comparable to those reported in other countries., and consequently do not represent any concern from a consumer safety point of view. The lack of strong correlation between histopathological changes and incidence of toxic elements found in our trial may explain the possible synergism among toxic elements and other nephrotoxic compounds, which enhances the toxicity, especially in cases of low contamination.