Effect of Chronic Exposure to Petroleum Hydrocarbon Pollution on Oxidative Stress Parameters and Histology of Liver Tissues of Native Fowl (Gallus domesticus).

The effect of chronic exposure to petroleum hydrocarbon (PHC) pollution on the concentrations of glucose, serum and liver malondialdehyde (MDA), protein carbonyl and the histology of liver tissues of the native fowl (Gallus domesticus) from Egbema in the Niger Delta Area (NDA) was studied. Identical fowls from an unpolluted area of Mbaise served as the control. Results showed no significant difference (P<0.05) in the mean glucose concentration obtained for fowls from both environments. The values obtained for serum and liver MDA and protein carbonyl for the test and control fowls were found to be significantly (P<0.05) different. There were elevated concentrations of MDA, protein carbonyl in the serum as well as MDA from liver homogenates of fowls from Egbema when compared to those of fowls from Mbaise. Histological changes were also observed in the liver sections of fowls from Egbema as against none in the liver sections of fowls from Mbaise. These changes were characteristically necrotic and inflammatory. Thus, the findings from this study show, in clear terms, that PHC pollution (crude oil and gas flaring) markedly affected the Egbema environment and induced changes in tissues of the native fowl whose nativity and ancestry are from there.

Effect of Sublethal Concentration of Heavy Metal Contamination on Soil Physicochemical Properties, Catalase and Dehydrogenase Activities.

The effect of sublethal contaminations (100 g/dm3) of heavy metals such as mercury (Hg), lead (Pb) and cadmium (Cd) on soil enzyme and physicochemical properties was investigated after one hundred and twenty days. Soil sample without heavy metal contamination served as the control. Results indicate that Hg, Pb and Cd at 100 g/dm3 concentration caused a significant (P<0.05) change in the soil pH and electrical conductivity relative to the control. There was no significant (P>0.05) difference in these soil physicochemical properties: moisture, phosphate, sulphate, chloride, calcium carbonate, total nitrogen and organic carbon when compared to the control. There were significant (P<0.05) decrease in soil dehydrogenase and catalase activities in all the metalcontaminated soil samples when compared to the control, indicating that these heavy metals increased soil acidity and electrical conductivity at this concentration and period of exposure.