Risk assessment of polychlorinated biphenyls (PCBs) in surface and groundwater in three states in Nigeria

ABSTRACT The study looked at the presence, distribution, and composition of polychlorinated biphenyls (PCBs) in rivers and wells in a specific region of Nigeria. It is critical to monitor their spread and presence in the environment. PCB levels in well water and rivers in Oyo and Delta states were measured using gas chromatography-mass spectrometry (GC-MS). The sample concentrations ranged from 0.02 ± 0.01 to 1.44 ± 0.04 mg/L, 0.01 ± 0.00 to 0.57 ± 0.02 mg/L, 0.02 ± 0.01 to 1.66 ± 0.01 mg/L, and 0.00 ± 0.00 to 13.18 ± 0.05 mg/L. The congener distribution patterns in these samples show a preference for highly chlorinated homolog compounds (penta- and di-PCB). The concentrations of PCBs in rivers and wells were below the 50 mg/L levels established by the Basel convention's persistent organic pollutant (POP) waste management criteria as a temporary criterion for low content in PCBs. The sample's PCB levels exceeded the US EPA's 0.00005 ppm standard. Furthermore, PCB levels exceeded the Dutch standard of 1,000 μg/L. River 3 exhibited the greatest mean concentration (32.04 ± 0.35 mg/L). Because of the progressive lifetime assessment of PCBs in these samples, anyone who was exposed to them ran a high risk of acquiring cancer. To assess their threat to the ecosystem, a surveillance plan must be created in these areas.