Heavy Metals Pollution and Other Physicochemical Parameters in the Crude Oil-Impacted Santa Barbara River and Environs, Bayelsa State, Nigeria

Abstract:

Higher levels of heavy metals in aquatic environments are most likely influenced by crude oil spills which may induce significant risk of heavy metal toxicity in aquatic species and humans. This research evaluated the levels of heavy metals and other physicochemical parameters in the crude oil-impacted Santa-Barbara River and environs of Bayelsa State, Nigeria. Heavy metals and other physicochemical parameters were examined using standard methods. Heavy metal pollution status was then deduced with standard pollution indicators. The water and fish samples collected from crude oil-impacted Santa Barbara River were heavily and moderately contaminated with iron, respectively (Igeo index = 4.29 and 2.87 for water and fish, respectively) and highly polluted with examined heavy metals (PLI = 4.29 and 1.13 for water and fish, respectively). The water samples from hand-dug wells were moderately contaminated with iron (Igeo index = 2.87) with overall low pollution by heavy metals (PLI = 0.46), while fish sold in neighboring communities was moderately contaminated with iron (Igeo index = 2.98) with overall moderate pollution by heavy metals (PLI = 0.86). However, potential ecological risks mediated by examining heavy metals in all water and fish samples were generally low (RI < 40). The total dissolved solids, biochemical oxygen demand, nitrate and phosphate concentrations in all water samples were within permissible limits of WHO and FEPA. The ecological risks associated with water and fish from all sampling locations were deduced as low, mainly because iron was the most abundant heavy metal contaminant with no significant toxic response.