Assessment Of Level Of Polychlorinated Biphenyls (PCBs) In Soil And Edible Crops From River Ala Floodplain In Akure

Flooding is one significant process that contributes to the movement of soil and sediments with the pollutants present in it along the river bank. With higher velocities of water, flooding can take contamination downstream. The soil, edible crops (rice and vegetables) samples were collected from Ala river floodplain in Ondo State and analyzed for their physico-chemical characteristics and level of Polychlorinated biphenyls present. The concentrations of nineteen (19) polychlorinated biphenyls (PCBs) were analyzed in soils collected at nine different sites along the floodplain and edible crops collected from six of the sites/ location using Gas Chromatography Mass Spectrometer (GC-MS) to determine the level of contamination of the floodplain and potential risks to the ecosystem and humans. The Ʃ-19 PCB concentrations in the floodplain soils varied between not detected (nd) -60 µg kg −1 , n.d – 60 µg kg −1 in vegetables and not detected to 80 µg kg −1 in rice across different locations. Higher concentration values were recorded in rice which suggests plants uptake and bioaccumulation potentials.The concentration of di to tetra homologues are more predominant in the samples. The concentration is lower than the value of permissible limit 2mg kg -1 recommended by Canadian Soil Quality Guideline (CSQG) and United States Environmental Protection Agency (US EPA). Dioxin-like PCBs were not detected