Bacteriological Health Status of Adjoining Dumpsite Soils in Uyo, Akwa Ibom State, Nigeria

Abstract

The bacterial population, distribution and physicochemical properties of soils adjoining a major dumpsite in Uyo, Nigeria were investigated to assess the effect of dumpsite wastes on the soil health. Composite soil samples (0-20 cm depth) collected from four (4) sampling points I, II, III, and IV were analysed using standard bacteriological and analytical techniques. Statistical analysis was performed using SPSS statistics 21 software. The results of the bacterial groups enumerated revealed counts ranging from 3.5±0.26×105 cfu/g to 6.0±0.10×106 cfu/g; 2.8±0.17×105 cfu/g to 2.4±0.20×106 cfu/g; 1.5±0.10×105 cfu/g to 1.8±0.17×106 cfu/g and 9.0±0.10×104 cfu/g to 1.3±0.10×106 cfu/g for Total heterotrophic bacteria (THB), Coliform bacteria (CB), Nitrifying bacteria (NB) and Phosphate solubilizing bacteria (PSB) respectively. At each sampling point, the distribution of THB was significantly higher (p<0.05) than all other bacterial groups. The bacterial isolates were mostly mesophilic species of Proteus, Streptococcus, Bacillus, Micrococcus, Pseudomonas, Staphylococcus, Citrobacter, Escherichia, Salmonella and Shigella with Bacillus predominating at every sampling point. Whereas physicochemical parameters were highest at sampling point I (closest to the dumpsite), the highest bacterial count were recorded at sampling point II and both reduced progressively away from the dumpsite. This study revealed that wastes generally increased bacterial proliferation as well as temperature with the release of nutrients, leachates and heavy metals which could adversely affect the health of soils at close proximity to the dumpsite. Hence, it is recommended that sanitary landfill with leachate cover should be constructed at designated locations so as to prevent surface/ground water pollution. Waste recycling technology should also be encouraged.