Concentrations and risks of polychlorinated biphenyls (PCBs) in transformer oils and the environment of a power plant in the Niger Delta, Nigeria

摘要

The concentrations of ?14 PCBs were determined, with the aid of gas chromatography-mass spectrometry (GC–MS), in transformer/turbine oils, soils, groundwater, and drainage water collected within a power plant in the Niger Delta of Nigeria. The ?14 PCB concentrations in the transformer oils, drainage water, groundwater and soils ranged from 484 to 48506 mg kgsup?1/sup, 0.99 to 2.95 mg Lsup?1/sup, 0.16 to 0.56 mg Lsup?1/sup and from 8.4 to 510 mg kgsup?1/sup respectively. The congener distribution patterns in these samples indicate the dominance of highly chlorinated homologues (hepta- and octa-PCBs). The Σ14 PCB concentrations in the transformer oils were above the provisional definition of low persistent organic pollutant (POP) content for PCBs of 50?mg?kgsup?1/sup as defined in the guidelines on the management of POP waste of the Basel Convention. The concentrations of ?14 PCBs in the soils were above the Dutch guideline value of 1000?μg kgsup?1/sup and the estimated incremental lifetime cancer risks relating to exposure of humans to PCBs in soils indicate serious health risks. There is therefore a need to implement a surveillance programme in the vicinity of power plants to determine the impacts on the adjacent ecosystem.