Public Health Implications of Waste Dump to Inhabitants in the Environment

Abstract

Dump sites are naturally associated with foul odour which obviously is product of microbial activities. The bacterial agents responsible for this decomposition may be injurious to humans. In order to determine the genera of bacteria responsible, Petri dishes containing three different types of media, nutrient, MacConkey and blood agars were exposed for fifteen minutes, and incubated at 37°C for 24 hours. Organisms that grew were analyzed to determine if they are pathogens. Five plates of each media were exposed, and the mean of the colony counts were expressed as colony forming units per millitre (cfu/ml). Three different dump sites were studied, namely school waste dump (SWD), Village waste dump (VWD) and Market waste dump (MWD). Results of Petri dish exposure for 15 mins showed mean cfu/ml of 300, 250 and 300 on nutrient agar for SWD, VWD and MWD respectively. 100, 120 and 150 on MacConkey agar for SWD, VWD and MWD respectively then 20, 15 and 25 on blood agar for SWD, VWD and MWD respectively. Cultural characteristics of the isolates revealed diverse shapes, margins, colours and sizes. Phenotypic characterization showed the Grain reaction, catalase, coagulase, motility, indole, oxidase tests, glucose fermentation, capsule and spore tests results of the isolates. Isolates were tentatively identified to be Listeria spp, Streptococcus spp, Escherischia spp, Staphylococcus spp, Bacillus spp, Shigella spp and Micrococcus spp, by Bergey's manual of determinative bacteriology. Virulence test by haemolysis assay showed both Streptococcus spp and Listeria spp to be α-haemolysis negative and β-haemolysis positive. Their zones of inhibition were 2-2.5 mm and 3.0-3.5 mm for Streptococcus spp, while Listeria spp was 1.5 mm. Capsule stain was positive for Streptococcus spp and Escherischia spp. Spore stain was positive only for Bacilluis spp. These finds show that pathogenic bacteria are associated with waste dumps and therefore can be injurious to public health.