Environmental and Public Health Implications of Using Abattoir Wastewater for Irrigation: Microbial Dynamics and Physicochemical Alterations in Agricultural Soils of Agbor and Environs

Abstract

Background: The reuse of abattoir wastewater for irrigation in developing countries, including Nigeria, offers potential benefits for soil fertility but poses significant environmental and public health risks due to high microbial loads, nutrients, and heavy metals. Aim: This study aimed to evaluate the impact of abattoir wastewater irrigation on the physicochemical properties and microbial communities of agricultural soils in Agbor and its environs. Methods: Wastewater and soil samples were collected from three abattoir sites and analyzed using standard microbiological, biochemical, and physicochemical procedures. Polluted soils were compared with unpolluted controls for bacterial counts, pathogen diversity, colony morphology, and biochemical traits. Results: Polluted soils showed significantly higher microbial loads and diversity, including pathogenic species (Escherichia coli, Staphylococcus aureus, Klebsiella sp., Enterobacter sp.), compared to pristine soils. Wastewater samples contained elevated fecal coliforms and heterotrophic bacteria, with variability across sites. Morphological and biochemical analyses confirmed the presence of both Gram-positive and Gram-negative pathogens. Conclusion: Untreated abattoir wastewater substantially alters soil microbial dynamics, increases pathogen prevalence, and threatens soil quality and food safety. Proper treatment and regulation are essential to mitigate environmental and public health risks associated with wastewater reuse in agriculture.