Human Health Risk Assessment of Polychlorinated Biphenyls (PCBs) in Fish from Eniong River, Nigeria

Abstract

Eniong River is an important source of seafood at commercial levels. Riverine communities also depend on it for other domestic uses. Potential human activities in the study area include boating, fishing, sand mining, and transportation, among others. These PCB-induced activities have been going on in the study area over the years, and there is no research data on PCB levels in fish in the area; hence, the need for this research. The objective of this study was to determine the concentration and distribution of PCBs in fish and sediment samples from the Eniong River. The determination of PCBs in fish samples from the river was done using standard procedures. Fish samples (96) (Clarias gariepenius) were collected from four sampling locations for twelve months. Extraction of samples was done using dichloromethane, hexane, and acetone. PCBs (28) congeners were determined using gas chromatography equipped with a mass spectrometer (GC-MS). The data obtained in this study were subjected to descriptive statistical analysis using the Statistical Package for the Social Sciences (SPSS). Analysis of variance (ANOVA) was used to test for significant differences in PCB concentrations across the sampling stations at P = 0.05. The results showed that the total PCBs (∑ 28 PCBs) concentrations in fish ranged from 30.26 to 107.07ngg-1. The hazard index values for non-cancer risk were less than unity, while the total cancer risk values were less than 10-6, indicating low risk. However, the toxic equivalent quotient of 12 DL- PCBs ranged from 4.6 E-03 to 2.7 E-02 ngg-1, indicating values greater than the upper limit of 6.5 E-03 stipulated by the European Food Safety Authority (EFSA) for all Dl PCBs in fish. Although the homolog composition did not differ significantly between the two seasons (p > 0.05). Most of the homologues recorded higher values in the wet season compared with the dry season. As a precautionary measure, the results indicated the need for urgent intervention to prevent escalation in levels of the pollutants in the commercial fish.