An In Ovo Investigation of the Ultrastructural Effects of the Heavy Metals Cadmium and Chromium on Liver Tissue

Many heavy metals are essential for human biological functions, but some heavy metals, especially at high concentrations, can have toxic, carcinogenic and/or teratogenic effects in humans. South Africa is the world’s largest reserve of minerals and due to extensive mining activity, air and water pollution occurs [1, 2]. Metal exposure occurs mostly through the ingestion of contaminated water; used for drinking, cooking and for agricultural purposes [3]. In this study the effect of heavy metals, cadmium (Cd) and chromium (Cr) were evaluated due to the high risk of exposure in South Africa. In recent studies, high levels of Cd and Cr were found in rivers and dams in several provinces in South Africa [4-6]. The most vulnerable population to be affected by heavy metal exposure is pregnant women with developing embryos and young children living in rural communities. In the human body, Cd and Cr are metabolized differently, but the consequences are similar namely oxidative stress that leads to DNA damage, apoptosis and lipid peroxidation [7-9]. Thus, the purpose of this study was to evaluate the ultrastructural effects of Cd and Cr on liver tissue by using the in ovo model. Analytical techniques energy dispersive spectroscopy (EDS) and electron energy-loss spectroscopy (EELS) were used to confirm the presence of these metals in liver tissue.