Search

This study assessed the human health hazards and ecological risks of heavy metals from waste sites in residential vicinity. The heavy metals analyzed were Cr, Pb, Cd, Ni, Cu, and Zn. A total of 40 soil samples were collected from waste sites in two residential estates located in the urban and suburb areas of Umuahia, Abia state. Results revealed a trend in concentrations of the heavy metals for both sites in the following order: Cu > Ni > Zn > Cr > Cd > Pb. The concentrations of heavy metals were higher in rural soils than in urban soil. The contamination factor (CF) indices for Pb, Cr, Cu, Ni, and Zn were less than 1 for both sites, signifying a low contamination scenario. The contamination factor for Cd (6 > CF) for both sites indicated a very high contamination status. The estimated degree of contamination (Cdeg) was less than the lower threshold of 8.0, denoting a low degree of contamination. Cd was the highest contributor to ecological risk with Er index value of 184.2 among measured heavy metals. The overall potential ecological risk index for urban and rural sites are 187.1 and 196.1 respectively, classifying the sites as moderate risk. The overall non-carcinogenic hazard index values (HI) for adults and children in urban and rural soils are 0.00248, 0.0198 and 0.0028, 0.0223 respectively, which are below the acceptable limit (HI < 1), indicating that the exposed residents are unlikely to experience any apparent adverse health hazards. However, children are more susceptible to non-carcinogenic hazards than adults in the study areas. [ABSTRACT FROM AUTHOR]

Abstract: This study evaluates the effect of water contaminated with phthalate, benzene and cyclohexane (major components of municipal waste in Nigeria) on the cellular system of Clarias gariepinus. Standard enzyme assays were conducted for alkaline phosphatase, acid phosphatase, alanine transaminase, aspartate transaminase, lactate dehydrogenase, gamma glutamyl transpeptidase of selected tissues of C. gariepinus cultivated in contaminated water over a period of 56days. Generally, a significant decrease in the activity of the enzymes of the tissues of C. gariepinus cultivated in contaminated water was observed relative to the control (p <0.05). Particularly, activity of alkaline phosphatase of liver of C. gariepinus cultivated in phthalate contaminated water was found to be 8.26±1.42 while that of control was 14.42±1.09. The activity of serum gamma glutamyl transpeptidase of serum of the same group of fish was found to be twice that of control. It could be inferred that membrane integrity of the tissues studied are compromised and that tissue dysfunction may result. Consumption of C. gariepinus cultivated in water contaminated with phthalate, benzene and cyclohexane could pose threats to public health. [Copyright &y& Elsevier]

Abstract: One of the major constraints to sustainable crop production on the Jos Plateau in Nigeria is low soil fertility status. Since the solution to the problem has long been perceived in terms of inadequate supply and distribution of inorganic fertilizers, maintenance of soil fertility has become one of the greatest problems facing both agricultural institutions and farmers in the area. With increased realization of the importance of organic fertilizers, which are now being used to provide useful supplement to inorganic ones, municipal waste is one of the organic fertilizing materials in use for quite some time now in Jos area. Farmers apply town waste in combination with poultry droppings and/or cow dung. Therefore, the objective of the study was to determine the effects of municipal waste application on soil properties. Two types of soil data were collected: Soil profile data and surface soil data. In each of the two study sites selected (Gangare and Naraguta) in the area, two profile pits were located, one in a farm where there has been application of town waste and the second in the adjacent reference area where there has been cultivation but no application of municipal waste. Stratified random sampling technique was adopted to collect surface soil samples. Standard procedures were applied in laboratory analysis. The results of soil analysis show that application of town waste has really modified the soil conditions. The surface soils in some areas have become very dark, classifying the soil as Mollisols. The levels of organic matter, total nitrogen, available phosphorus, exchangeable bases and CEC have been greatly enhanced. However, the contents of some trace elements have increased too. [Copyright &y& Elsevier]