Health Risk Assessment of the Urban Stretch, Lower Niger Rivers with References to Aquatic Biota and Anthropoids

ABSTRACT
Background and Objective: The lower Niger River at Swale does not serve as a source of water to human-only but also to anthropoids. However, the river is drained by many hazardous pollutants due to anthropogenic activities. Therefore, the occurrence of priority hazardous Polycyclic Aromatic Hydrocarbons (PAHs) in water, suspended particulates matter, and bottom sediments of the urban stretch of the rivers at the Swale market was investigated. Materials and Methods: Thirty-six samples were collected monthly, comprises of surface water, suspended particles and bottom sediments were collected monthly. Water samples was extracted using Liquid-liquid extraction method, using a mixture of dichloromethane and n-hexane, while soxhlet extraction was used for the extraction of suspended particles and sediment samples. The samples were analyzed by means of gas chromatography/mass spectrometry. One-way analysis of variance was used to compare the significance of the differences of total PAHs between different matrixes and seasonal variation. Results: The mean Concentration of Total PAHs and seasonal distribution in the surface water suspended particles and bottom sediments of the lower Niger Delta Rivers, Nigeria at Swale varies significantly between the seasons and the matrixes (p < 0.05, F = 7.30). Higher concentrations were observed in the wet season than the dry season in all the matrixes, with the bottom sediments having the highest concentrations (7270±4.10 µg/gdw), followed by suspended particles (1320±7.80 µg/gdw), while the surface water had the least (357.90±2.20 µg/L). Conclusion: The high concentrations recorded in these matrixes is that the aquatic organisms can bioaccumulates along the food chain. The pollution load of PAHs in this lower Niger river at the Swale market must therefore be reduced to improve the health of ecosystems, thereby guaranteeing safe human consumption of fish and other aquatic organisms.