Studies of Persistent Organic Pollutants in Selected Locations in Jos, Plateau State Nigeria
Background: Twenty soil and ten water samples from electrical transformer installation sites of Jos Electricity distribution Company were investigated for physiochemical properties and Persistent Organic Pollutants (POPs). Five additional water samples from industrial sites were analyzed for organochlorine pesticides.
Methods: For the polychlorinated biphenyls, 10g of the soil sample was mixed thoroughly with anhydrous sodium sulfate and extracted with 40mL of hexane-acetone mixture (1:1 v/v) in ultrasonic bath for twenty minutes, while the water samples 200ml were extracted using EPA method 3510. The extracts were cleaned up by column chromatography using silica gel (120 meshes) and hexane as eluting solvent (EPA method 3550). The extracts were concentrated using rotary evaporator and fifteen PCBs congeners were quantified using Agilent GC-MS 6975. The physicochemical parameters were determined using AOAC method 2000.
Results: The findings show the soil was acidic with pH range from 5.53-6.42, organic matter (3.36-6.62%), phosphorus (0.50-8.20ppm), Cat ion exchange capacity (2.42-3.00), Electrical conductivity (0.03-0.20u/cm), moisture content (3.65-35.62%) and total organic carbon (2.06-3.81%), Nitrogen (0.06-0.13%). For exchangeable bases Calcium (198-347ppm), Sodium (0.8-12ppm), Magnesium (68-96ppm), Potassium (2.0-25ppm).For the exchangeable acidity H+(1.54-1.70mMol/100g). Fifteen PCBs congeners were identified and quantified with the following concentrations, PCB 18 (0.00-0.05mg/kg), PCB 20 (0.27-0.70mg/kg), PCB 28/29 (0.28-0.39mg/kg), PCB 44 (0.15-0.54mg/kg),PCB 52 (0.09-5.84mg/kg), PCB 101 (0.38-0.51mg/kg), PCB 105 (0.17-0.36mg/kg), PCB 118 (0.00-0.51mg/kg), PCB 137 (0.45-1.79mg/kg), PCB 142 (0.00-0.55mg/kg), PCB 153 (0.37-1.20mg/kg), PCB 170 (0.15-1.59mg/kg), PCB 180 (0.00-0.47mg/kg) and PCB 194 (0.00-0.32mg/kg) respectively in soil. Only Nine PCBs were identified and quantified in water samples with concentrations range from 0.00mg/L to 0.28mg/L. For the organochlorine only Diedrin was quantified with a concentration of 1.87ppm.
Conclusion: The results shows the concentrations of the PCBs are linked with the age of transformers and PCBs have affinity for soil and not water. The PCBs in soil samples were below canadian guideline value of 33mg/kg for Industrial soil while the water samples were above the guidelines values of 0.0094mg/L.
Keywords: Persistent, PCBs, GC-MS and Pollutants.