ORIGINAL RESEARCH ARTICLE - Assessment of the health risks associated with human dietary exposure to polycyclic aromatic hydrocarbons in Nile tilapia from Agboyi creek, Southwest Nigeria

Abstract

Increasing levels of persistent organic pollutants in aquatic ecosystems have been a major challenge in many regions of the world due to their potential adverse effects on ecological receptors and humans via the food chain. This study assessed the risk associated with dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in muscle tissues of Nile tilapia Oreochromis niloticus from Agboyi creek in Southwest-Nigeria. The concentrations of PAHs were determined using Gas Chromatography-Mass Spectrometry (GC-MS) following United State Environmental Protection Agency (USEPA) methods. Of the 16 priority PAHs screened, the mean concentration of Acenaphthene (60.51 ± 69.85 μg/kg), the most dominant of all detected PAHs accounted for 19 % of total PAHs while Benzo (a) pyrene with the lowest mean concentration of 0.08 ± 0.17 μg/kg accounted for 0.03 % of total PAHs recorded. Estimated human daily intake (EDI), Hazard Quotient (HQ) and Hazard Index (HI) of PAHs in fish through human consumption were less than the reference dose (RfD) and threshold value. However, obtained toxic equivalent concentration (TEC) for Benzo (b) fluoranthene (35.79 μg/kg) and Dibenz (a, h) anthracene (56.25 μg/kg) as well as the estimated excess cancer risk (ECR) values for 7 most toxic PAHs in fish tissues exceeded the calculated screening value of 0.0027 μg/g and the 'acceptable' range of risk (˃ 10-6) set by the United State Environmental Protection Agency (USEPA) respectively. Dietary exposure to some PAHs recorded in the tissue of Nile tilapia from Agboyi creek may have consequent health implications on the consumers.