Polychlorinated biphenyls residues in bivalve shellfish from Niger Delta: distribution pattern, tissue burden and food safety assessment

This study investigated the distribution pattern, tissue burden, and safety of bivalve shellfish for human consumption. Edible species of bivalve shellfish harvested from Niger delta were screened for polychlorinated biphenyl (PCB) contaminants. Instrumental analysis and quantification of PCB congeners were performed using gas chromatography fitted with electron capture detector (GC-ECD). Results indicated an accumulation of PCB concentration of 0.36 ng/g, 0.89 ng/g, 0.98 ng/g, and 1.73 ng/g at Andoni, Iko Town, Ibeno, and Bonny, respectively. The PCB burden showed bloody cockle at Bonny location recorded the highest concentration of PCB congeners (2.37 ng/g), closely followed by mangrove oyster (2.13 ng/g) at Iko Town location, while Donax clam at Ibeno (0.09 ng/g) has the least PCB burden. The results obtained were lower in relation to food regulatory threshold. However, PCB tissue burden of bivalve shellfish harvested at the study locations indicated an environment impacted by anthropogenic activities that could negatively affect human health which depends on these shellfish for food.