Environmental assessment of ground water pollution by heavy metals and bioaccumulation of mercury residues in chicken tissues
The aim of this study was to investigate the relationship between the concentrations of heavy metals in well water and bioaccumulation of the most abundant metals in chicken tissues in some areas in the province of Mecca Almokaramah, Saudi Arabia. Among the heavy metals (Cd, Zn, Cr, Mn, Cu Hg, Pb and Ni) studied, mercury (Hg) revealed highest in concentration in well waters. The concentration of mercury in ground water, beside in liver, kidney, muscle and blood samples of 10 chickens from each of four poultry- production farms were estimated using atomic absorption spectrophotometer. The present results showed that the kidney followed by liver are the organs with the highest bioaccumulation of mercury in all farm samples. The level of mercury in ground water was 7.06 μg/L. There is no doubt that the relationship between mercury accumulation levels in kidney and those in liver tissues were proportionally correlated and altered with elevation in antioxidant enzyme activities such as serum enzymes aspartate aminotransferase (AST) and serum glutamate pyruvate transaminase (GPT). These elevated enzymatic activities were induced by the level of toxicity. There was a significant elevation in the level of liver and kidney malondialdehyde (MDA), while the activities of antioxidant enzymes superoxide dismutase and catalase (SOD and CAT) were significantly decreased. Biochemical observations were supplemented by histopathological examination of liver and kidney sections.
Key words: Environmental toxicology, ground water, heavy metals, mercury, bioaccumulation- chicken histopathology.