Assessment of Physico-Chemical Parameters and Polycyclic Aromatic Hydrocarbons (Pahs) Concentrations in Fish and Water from a Stretch of River Niger, Anambra State, Nigeria

Okeke PA, Ohaturuonye SO, Nwosu PO, Cyprian GC and Amachree D

Published on: 2025-01-11

Abstract

Studies on the physico-chemical parameters and polycyclic aromatic hydrocarbons (PAHs) in fish and water samples from a stretch of River Niger namely: Odoekpe (Sampling Station I- SS I), Atani (Sampling Station II- SS II) and Ossomalla (Sampling Station III- SS III) axis in Anambra State, Nigeria was carried out for a period of four months (July to October, 2023) to determine their levels of concentration. The sampled specimens were collected using the best acceptable practices and were taken to Docchy Analytical Laboratory and Environmental Services, Awka, Anambra State for analysis. Some physico-chemical parameters such as temperature and pH were taken in-situ while others which include dissolved oxygen (DO), biological oxygen demand (BOD), alkalinity, nitrate, magnesium, phosphate, were analyzed in the laboratory. The polycyclic aromatic hydrocarbons (PAHs) were analyzed using Gas Chromatography methods and were determined using Varian AA 240 Atomic Absorption Spectrophometer according to American Public Health Association. The results obtained indicated that the physico-chemical properties of water in the sampling stations were within the permissible limits set by World Health Organization (WHO), except for turbidity, and transparency. The results of polycyclic aromatic hydrocarbons (PAHs) revealed that Benzo(a)pyrene recorded the highest concentration (0.185) in the water followed by 1_2 Benzanthracene (0.051) while Benzo(b) flouranthene had the least (0.001).In fish samples obtained from the river, Benzo(a)pyrene recorded the highest concentration (0.182) followed by Benzo(g_h_I)perylene (0.058) while Benzo(b)flouranthene had least (0.002). The results from the study further indicated that the values of PAHs were significantly (P<0.05) higher in fish and water samples from station II when compared to other sampling stations. However, the components of PAHs in both fish and water were found to be lower than the recommended limits by WHO. In spite of this, continuous monitoring and surveillance of this river is important to assess the trends of PAHs overtime, in order to detect any emerging risk in a dynamic river such as River Niger.