Evaluation of Petroleum Hydrocarbon Pollution in Soils Impacted by Artisanal Refining in Bayelsa, Nigeria

Abstract

Artisanal refining of crude oil is widespread in the Niger Delta and poses serious threats to soil quality, ecosystem function and human health. This study evaluated the extent, composition and potential impacts of petroleum hydrocarbon pollution in soils impacted by artisanal refining of crude oil in Bayelsa State, Nigeria. Soil samples were collected from two major artisanal refining hotspots and from a background location. Total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs) were analyzed using GC-MS, following standard procedures. Speciation of the PAHs was also carried out. The results revealed markedly elevated concentrations of petroleum hydrocarbons in soils at refining sites compared with background locations and applicable regulatory standards, with distinct spatial hotspots occurring in areas where refining activities persisted for longer durations. PAH profiles showed predominance of higher-molecular-weight, persistent compounds, including those with known carcinogenicity. Risk calculations signaled both ecological and human-health concerns. The findings point to the need for targeted remediation, continuous environmental monitoring, stronger enforcement of regulations and community-centered alternatives to artisanal refining. The study provides a baseline for remediation planning and for policymaking to reduce long-term environmental and public-health burdens in Bayelsa