Assessment of Environmental Health Risks in Informal Artisanal Refining Clusters in Imo State

Artisanal petroleum refining clusters operating outside regulatory oversight in the South South and South East zones generate acute environmental health risks for workers and proximate communities through uncontrolled emissions, soil contamination, and water pollution. This study assesses environmental health risks in three artisanal refining clusters in Imo State using a professional risk assessment methodology combining environmental sampling, health survey, and hazard characterisation. Soil, water, and ambient air quality were measured at cluster locations and control sites, with particular focus on total petroleum hydrocarbons, benzene exposure concentrations, and particulate matter levels. Health surveys administered to 80 workers and 120 community residents proximate to clusters documented self-reported symptoms, exposure histories, and utilisation of health services. Carcinogenic and non-carcinogenic health risk indices were computed for priority contaminants using established toxicological reference values. Results indicate benzene ambient concentrations in worker breathing zones exceeding occupational exposure limits by a factor of four to seven, representing significant cancer risk under chronic exposure scenarios. Community residents within 500 metres of clusters demonstrate elevated odds ratios for respiratory symptoms, skin complaints, and headache compared to control populations. Contaminated groundwater consumed by communities lacking alternative supplies presents a secondary exposure pathway of concern. The study recommends regulatory classification of artisanal refining as a priority environmental health risk, targeted health surveillance programmes, and development of transition pathways to legal and cleaner refinery operations. Keywords: artisanal refining, environmental health, petroleum contamination, Imo State, health risk assessment.