Comparative Analysis of the Physicochemical and Bacteriological Characteristics of Meat Processing Wastewater and their Environmental and Public Health Assessment in Cameroon

Abstract

Aims: To assess and compare the pollution load from a modern slaughterhouse facility and a local market slaughter site in Yaoundé, Cameroon, in order to evaluate how facility size and operational practices influence environmental contamination and public health risks. Study Design: Descriptive comparative cross-sectional study. Place and Duration of Study: The study was conducted at a municipal slaughterhouse (SH1) and a local market slaughter site (SH2) in Yaoundé, Cameroon, over a period of six months, with bi-monthly sampling and surveys. Methodology: Surveys were administered to 20 workers and 120 residents per site to collect socio-environmental data. Wastewater samples from both sites were collected twice per month and analyzed for key physicochemical parameters (pH, T°, EC, TSS, TDS, Color, NO3-, NH4+, PO34-, Cl-, BOD₅, COD, Fe2+, Cu2+, Cr6+) and bacteriological parameters (fecal coliforms). Water sources, wastewater generation volumes, and community health complaints were also recorded. Data were statistically compared between the two sites to identify differences in pollution load and related health effects. Results: SH1 relied mainly on municipal water (47.5%) and generated higher wastewater volumes (5.1–7.9 m³/month) than SH2 (2.8–4.8 m³/month), which depended on wells (52.5%). SH1 exhibited greater pollution levels with BOD₅ = 3198 ± 296 mg/L, COD = 16,232 ± 3315 mg/L, and fecal coliforms = 6.2 × 10⁷ ± 3.6 × 10⁷ CFU/100 mL, while SH2 showed lower BOD₅ = 1702 ± 731 mg/L and COD = 7736 ± 869 mg/L, but higher conductivity = 4496.7 ± 1096.4 µS/cm. Both sites exceeded national and EU discharge standards. Odor was the most reported nuisance (22.8% at SH1; 23.6% at SH2). SH1’s wastewater correlated with respiratory (16.67%) and skin infections (16.52%), whereas SH2’s effluent was linked to waterborne diseases (14.34%). Conclusion: Both slaughter sites significantly pollute their surrounding environments, with SH1 showing a higher overall pollution load. Untreated effluent discharge poses serious environmental and public health risks. Immediate implementation of appropriate wastewater treatment and management systems is essential to mitigate contamination and improve sanitary conditions.