Polychlorinated Biphenyls in Imported Fish

Abstract

Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) which have been described as organohalogenic and legacy contaminants that are hazardous to both wildlife and man. The paucity of ecotoxicological data on the PCB content in commercially important fish in Benin Metropolis, Nigeria, warranted this research. In this stead, the PCB profile in the Atlantic Herring (Clupea harengus, Family: Clupeidae, mean length=31.59 cm; Mean weight=274.98 g) marketed in Benin Metropolis, was determined via Gas Chromatographic technique in order to evaluate its suitability for human consumption and to provide baseline data for this contaminant in commercially important fish species. The summary statistics for the mean concentrations of detectable PCBs in C. harengus ranged from 0.019 mg/kg (PCB 118, 156) to 0.434 mg/kg (PCB 126), with a total of 0.581 mg/kg (w/w) while the mean concentrations of PCBs in C. harengus by market ranged from 0.012 mg/kg (PCB 118) at Santana market to 0.526 mg/kg (PCB 126) at New Benin market with no observed significant difference (p>0.05) in the mean concentrations of PCBs in fish between markets. The toxicity quotient (TQ) values for PCBs in C. harengus ranged from 0.0095 (PCB 118, 156) to 0.217(PCB 126) while the estimated daily intake (EDI) values in mg/person/day for PCBs ranged from 0.00076 (PCB 118, 156) to 0.017 (PCB 126). A toxic equivalency (TEQ) value of 0.04342 while the total PCB content in C. harengus according to market ranged from 0.469 mg/kg (Santana market) to 0.658 mg/kg (Uselu market). The total toxicity of mixtures (TTM) index was 0.291. The PCB levels in fish decreased below International threshold values suggesting suitability for human consumption. Continous monitoring of this fish species for toxic concentrations of PCBs was proferred.