Assessment of Polychlorinated Biphenyls (PCBs) in Water, Sediments and Biota from EwasteDumpsites in Lagos and Osun States, South-West, Nigeria

The levels of PCBs in sediments, water, leachate and aquatic fauna (Tilapia guineensis, Callinectes amnicola and Cardiosoma armatum) found in and around e-waste dumpsites in Lagos and Osun States, South-West, Nigeria were analyzed using Gas Chromatography Electron Capture Detector (GC ECD) Agilent 7820A. All the 28 PCBs congeners studied were detected with the ∑hexa-PCBs dominating in Lagos (21%) while the ∑tetra-PCBs (24%) enriched the samples from Osun State. The concentrations of ∑- PCBs in decreasing order were Lagos: sediment ˃ fish gill ˃ fish muscles ˃ water ˃ crab ˃ leachate and Osun: fish gill ˃ fish muscle ˃ sediment ˃ crab ˃ water ˃ leachate. The concentrations of total indicator PCBs ( ∑7PCBs) in the sediment from Lagos (4.19 µg/kg) and Osun (8.58 µg/kg) exceeded the Canadian Sediment Quality standard threshold effect level (CSQ TEL) (0.03 µg/kg) and the National Oceanic Atmospheric Administration threshold effect level (NOAA TEL) for fresh and marine sediments.. The calculated toxic equivalent quotient (TEQ) for fish from Lagos and Osun (3.7 and 4.4) respectively further suggests a likely occurrence of adverse effects to humans who consume the fish. This study reveals the high health and ecological risks associated with e-waste pollution in the aquatic environment.