Effects of water-soluble fractions of crude oil on physicochemical quality and heavy metal status of River Ethiope at Abraka, Nigeria

Abstract

Crude oil exploration and exploitation has impacted the environment and humans negatively. The effects of Water Soluble Fractions (WSFs) of Universal Energy Akwa Ibom crude oil on River Ethiope, Abraka, Nigeria were assessed so as to ascertain its physiochemical qualities and the presence of heavy metals. Physicochemical qualities were determined following standard procedures of APHA and AOAC. The impacts of WSFs on the physicochemical parameters was significant when compared with water sample controls from River Ethiope but were still within the limits of WHO. Chemical Oxygen Demand (COD), turbidity, total alkalinity, calcium, nitrates and HCO₃ had levels higher than water samples controls. Other parameters were either lower in water sample control or did not differ significantly in values between the water samples and WSFs of crude oil.COD, DO, BOD, turbidity, conductivity, sulphate, calcium, magnesium, potassium and chloride ion had values lower than the WHO recommended range. Both water samples and WSFs contained traces of heavy metals. All trace heavy metals in water samples and WSFs were lower in levels when compared with WHO recommended levels except lead which had a higher levels in the WSFs. Although most of the parameters and heavy metals determined in this study were within the WHO permissible levels for drinking water, there is the need to exercise precaution because of the health risks associated with metal load and their non-degradable nature. Hence, regular monitoring by regulating bodies to avoid possible bioaccumulation and biomagnification along the food chain and webs is necessary.