CONCENTRATIONS AND ASSOCIATED RISK OF SELECTED ALIPHATIC HYDROCARBONS IN SEDIMENTS FROM RIVER ETHIOPE, SOUTHERN NIGERIA

Abstract

The contamination of aquatic ecosystems by hydrocarbon compounds poses severe environmental and human health concerns. Hence this study aimed to investigate the concentrations and associated risk of selected aliphatic hydrocarbons in sediments from the River Ethiope, an important water resource in Nigeria. A comprehensive sampling was conducted, collecting sediment samples at various locations (Umuaja, Obinoba, Abraka, Eku, Okpara, Aghalokpe, and Sapele) along the river. The samples were analyzed using gas chromatography (GC) to quantify the concentrations of hydrocarbons, with a specific focus on aliphatic hydrocarbons. These compounds are known for their potential adverse effects on human health and the environment. From the results obtained in this study, the total concentrations of Aliphatic compounds at various site from sites ranged from 10897 - 316783 µg/kg in (C8-C39), with Okpara containing the highest concentration and Eku with the lowest concentration. Hydrocarbon C36 was not detected in Umuaja while hydrocarbon C37 was not discovered in Aghalokpe, Okpara-Waterside and Sapele. Also, hydrocarbon C10, C11 and C12 was not detected in Okpara-Waterside and Sapele. There were significant differences (p<0.05) in all hydrocarbons detected among the different sampling locations except in hydrocarbon C34 which showed no significant different (p>0.05). The outcome of this study from carbon preference index (CPI) reveals that the major source of hydrocarbon contamination is associated with petroleum activities and have contributed valuable information for environmental monitoring programs, policymaking, and decision-making processes aimed at safeguarding water quality and mitigating the potential detrimental effects of hydrocarbon contamination in similar aquatic environments.