Environmental Health Risks of Artisanal Cassava Processing and Effluent Management in Edo State, South South Nigeria

Cassava processing is a major agro-industrial activity in Southern Nigeria, and the effluent generated, known as cassava wastewater or steep water, contains high concentrations of cyanide, organic matter, and suspended solids. This study evaluated environmental health risks associated with artisanal cassava processing and effluent management practices in Ovia North East Local Government Area, Edo State. Field assessments of thirty artisanal processing units were conducted, and effluent samples from processing sites and adjacent water bodies were analyzed for pH, cyanide, biological oxygen demand, and coliform bacteria. A community health survey was administered to 250 residents living near processing clusters. Results showed that mean cyanide concentration in cassava effluent discharge ranged from 48 to 112 mg/L, significantly exceeding permissible limits for wastewater discharge of 0.2 mg/L. Biological oxygen demand values in receiving streams reached 1,200 mg/L, indicating severe organic contamination. Ninety-two percent of processing units discharged effluent directly into open fields, drainage channels, or streams without treatment. Community residents reported chronic odor nuisance, skin irritation, and digestive complaints correlated with proximity to processing sites. Aquatic life in three sections of affected streams appeared severely impacted based on visual assessment and reduced diversity records. The study recommends development of low-cost effluent treatment systems for artisanal processors, community buffer zone designations, and regulatory engagement by the Edo State Environmental Quality Control Board. Keywords: cassava processing, effluent, cyanide, Edo State, water contamination.