Geospatial Dynamics of Artisanal Petroleum Refining and Environmental Contamination in Imo State

Artisanal crude oil refining, locally termed illegal bunkering and kpo-fire refining operations, has proliferated across oil-producing communities of Imo State and the broader South South and South East geopolitical zone interface, generating severe environmental contamination in soil, water, and air while contributing to oil theft losses estimated at billions of naira annually. This study analyses the geospatial dynamics of artisanal refining activity and its environmental contamination footprint in Ohaji/Egbema and Oguta local government areas of Imo State. Activity hotspot mapping was conducted using a combination of Sentinel-1 SAR backscatter anomaly detection (to identify combustion signatures), Sentinel-2 false colour composite analysis (to detect contaminated bare earth and oil sheen in water bodies), and GPS-verified field survey data from 38 identified refining sites. Soil samples from 30 refining sites and 30 matched control locations were analysed for total petroleum hydrocarbons, polycyclic aromatic hydrocarbons, and heavy metals. Community exposure surveys with 280 households assessed proximity to refining sites, health symptoms, and economic dependencies on refining value chains. Results document 38 active refining sites across the two LGAs, covering a combined operational footprint of approximately 420 hectares. Total petroleum hydrocarbon soil concentrations at active sites exceed DPR remediation trigger values by factors of 18 to 64. Community surveys document high rates of respiratory complaints, skin conditions, and eye irritation among households within 200 metres of active sites. The study recommends an integrated response combining remediation, alternative livelihoods, and strengthened monitoring rather than enforcement-only approaches. Keywords: artisanal refining, petroleum contamination, Imo State, South East Nigeria, illegal bunkering.