Accumulation of Polychlorinated Biphenyls (PCBS) in Soil and Water from Electrical Transformers Installation Sites in Selected Locations in Jos Metropolis, Plateau State, Nigeria

Abstract

Soil and water samples from surroundings of selected Electricity Transformer installations belonging to the Jos Electricity Distribution (JED) Plc, Jos were analyzed for different congeners of polychlorinated biphenyls (PCBs) widely used as coolants. The EPA 3550 and 3510 methods were used for the sampling, preparation and extraction of the soil and water samples respectively. The extracts were cleaned up using column chromatography packed with silica gel (120 mesh). Thereafter, it was concentrated for characterization and quantification using Gas Chromatography coupled with Mass Spectroscopy Detector (GC-MSD). Fifteen (15) congeners were identified and quantified in the soil samples. The result obtained shows C₅₂ to have the highest concentration with the value of 5.84 mg/kg. The range for the concentrations of the various congeners identified are: C18 (0.00-0.05 mg/kg), C20 (0.27-0.70 mg/kg), C₂₈ (0.28-0.39 mg/kg), C₂₉ (0.28-0.39 mg/kg), C₄₄ (0.15-0.54 mg/kg), C₅₂ (0.09-5.84 mg/kg), C₁₀₁ (0.38-0.51 mg/kg), C₁₃₇ (0. 45-1.79 mg/kg), C₁₄₂ (0.00-0.55 mg/kg), C₁₅₃ (0.37-1.20 mg/kg), C₁₇₀ (0.15-1.59 mg/kg), C₁₈₀ (0.00-0.47 mg/kg) and C₁₉₄ (0.00-0.32 mg/kg). Similarly, for the water samples only C₂₀, C₂₈, C₂₉, C₁₀₁, C₁₀₅ and C₁₅₃ were identified and quantified. The result shows C₁₅₃ having the highest concentration with the value of 0.57 mg/l followed by C₁₀₅ (0.48 mg/l), C₁₀₁ (0.37 mg/l), C₂₈ and C₂₉ have same concentration of 0.28 mg/l. From thirty samples analyzed, the result of the soils is below the Canadian Reference maximum allowable limit while that of water has some values higher than the recommended allowable limit. The studies showed various concentrations are link with ages of Transformer installation, as those installed earlier had more congeners with higher concentrations than the recent ones.