MICROBIAL DIVERSITY AND PHYSICOCHEMICAL ANALYSIS OF SOIL FROM DUMPING SITES AT JENTA ADAMU

ABSTRACT Soil pollution resulting from indiscriminate waste disposal has become a major environmental and public health concern, particularly in developing countries. Dumpsites often serve as reservoirs of organic matter, heavy metals, and pathogenic microorganisms, thereby altering the natural balance of soil ecosystems. This study investigated the microbial diversity and physicochemical properties of soil from the JentaAdamu dumping site in Jos Metropolis, Plateau State, Nigeria. A total of 30 soil samples were collected from surface (0–10 cm), subsurface (10–20 cm), and control (uncontaminated) sites. Microbial analyses were performed using standard microbiological procedures, including serial dilution, plating on Nutrient Agar (for bacteria) and Sabouraud Dextrose Agar (for fungi), followed by morphological, biochemical, and microscopic characterization of isolates. Soil samples were also examined for parasitic organisms using sedimentation and microscopy. Physicochemical analyses included determination of soil pH, temperature, moisture content, organic matter, macronutrients (N, P, K, Ca, Mg), and heavy metals (Pb, Cd, Cr, Cu, Zn) using standard methods and Atomic Absorption Spectrophotometry (AAS). The results showed that surface soils had the highest microbial loads, with mean bacterial counts of 8.45 × 106 CFU/g and fungal counts of 6.32 × 104CFU/g, compared to subsurface and control soils. A total of eight bacterial genera were identified, dominated by Bacillus spp. (24.4%) and Pseudomonas spp. (20.0%), while opportunistic pathogens such as Escherichia coli and Staphylococcus spp. were also detected. Among fungi, seven genera were isolated, with Aspergillus spp. (28.6%) and Penicillium spp. (20.0%) being the most prevalent. Soil samples also harbored parasites, with Ascarislumbricoides (30%) being the most frequently detected, indicating fecal contamination. Physicochemical results revealed near-neutral pH (6.3-6.4) in contaminated soils, higher organic matter (5.26% in surface soil), and elevated macronutrient concentrations compared to the control. Heavy metal analysis confirmed significant enrichment of Pb, Cd, and Zn in dumpsite soils relative to uncontaminated soils. The findings demonstrate that JentaAdamu dumpsite soils are microbially rich but highly contaminated, supporting both beneficial decomposers and pathogenic microorganisms, alongside elevated nutrient and heavy metal loads. This highlights potential risks to public health and the environment, particularly groundwater pollution and disease transmission. The study recommends improved waste management strategies, regular monitoring of dumpsites, and public health awareness campaigns to mitigate the hazards associated with uncontrolled waste disposal.