Variation of Soil Physicochemical Conditions and Teir Influence on Enteric Pathogen Load from Landfills in Zaria, Kaduna State

Abstract: Landfills represent complex ecosystems where varying physicochemical conditions significantly shape microbial dynamics, including the survival and proliferation of enteric pathogens. This study investigated the variation of soil physicochemical conditions and their influence on enteric pathogen load in landfill soils within Zaria, Kaduna State. Fifty-two (52) soil samples were collected in duplicate from each of these four locations, Tudun-Wada, Zaria city, Sabon-Gari and Samaru landfills in Zaria. Standard analytical procedures were employed to determine temperature and pH. The results showed that soil temperature ranged between 29.51°C and 34.13°C, while pH values varied from 7.16 to 8.27, indicating slightly alkaline conditions. Microbial analysis was conducted using serial dilution and selective culture techniques for the enumeration of enteric pathogens. The mean bacterial counts ranged from 2.1×10⁸ to 3.3×10⁸ cfu/g across sampling locations. Statistical analysis using Pearson Correlation revealed a strong positive correlation (r = 0.653) between temperature, pH, and bacterial counts, suggesting that variations in these parameters significantly influenced microbial proliferation. Principal Component Analysis (PCA) further showed that temperature accounted for 65.4% of the variation in microbial activity, whereas pH contributed 18.7%, emphasizing the dominant role of temperature in shaping microbial dynamics in landfill soils. Pathogenic bacteria identified included Salmonella enterica (6.92%), Vibrio cholerae non-O1 (1.35%), and Escherichia coli O157:H7 among other species. The findings highlight those physicochemical conditions, particularly in temperature and pH, strongly influence the survival and distribution of enteric pathogens in landfill environments, posing potential risks to public and environmental health.