An ecotoxicological appraisal of polychlorinated biphenyls in the blue whiting (Micromesistius poutassou, Risso 1826) from cold storage facilities in Benin City, Nigeria

Abstract

Polychlorinated biphenyls (PCBs) are halogenated organic pollutants that  remain a threat to wildlife and man. The present study strove to fill an existing gap in knowledge while at the same time providing vital consumer information that could ultimately safeguard human health with regard to the PCB burden in the Blue Whiting Micromesistius poutassou (mean total length: 31.46 ± 0.87 cm; mean weight: 498.25 ± 0.48 g) sourced from cold storage facilities in Benin City, Nigeria, applying Gas Chromatographic technique. The overall mean values (Mg/kg) for PCB congeners in M. poutassou ranged from 0.01813 for PCB 189 to 0.1306 for PCB 126 with a total (ƩPCB4) of 0.1929. The mean PCB values (Mg/kg) in M. poutassou according to cold storage points ranged from 0.0156 (PCB 189) at Uselu to 0.137 (PCB 126) also at Uselu with no observed significant difference (P>0.05) in the mean concentrations of PCBs 118, 157 and 189 in M. poutassou between cold storage points. The hazard quotient (HQ) values ranged from 0.00906 (PCB 189) to 0.0653 (PCB 126) while the toxic equivalency (TEQ) was 0.013075. The estimated daily intake (EDI) and estimated annual intake (EAI) values for PCBs were both at a peak for PCB 126 with figures of 0.000068 Mg/person/day and 0.024 Mg/person/year. The percent (%) quota for PCBs in M. poutassou ranged from 9.39 % (PCB 189) to 67.70 % (PCB 126). The spatial total (Mg/kg) for PCBs in M. poutassou ranged from 0.1808 at Oba market to 0.2013 at Uselu while the temporal total (Mg/kg) for PCBs in M. poutassou ranged from 0.1888 in September to 0.1943 in October. The fish species was considered safe for human consumption as the observed levels of PCBs fell within International thresholds. Continuous monitoring of PCB levels in M. poutassou was however recommended.