Determination of Polychlorinated Biphenyls in Soils and Industrial Effluents and Health Risks Assessment in Uyo, Akwa Ibom State, Nigeria

Abstract

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are ubiquitous in nature and are available in all environmental components, and are implicated as being carcinogenic. In this study, the levels of PCBs were evaluated in soils and effluent water obtained from an industrial area in Uyo Local Government Area, Akwa Ibom State, Nigeria. The work also assessed the possible relationship between the parameters and risks posed by polychlorinated biphenyls via several pollution indices. A total of four (4) Soil and effluent samples were collected during the rainy season and analysed using USEPA Method 8082 and gas chromatography–mass spectrometry (GC–MS). The concentrations of total PCBs in the soil samples were: Soil1 (∑ PCBs 234.447 ug/kg), Soil 2 (∑ PCBs 216.000ug/kg), Soil 3 (∑ PCBs 195.375 ug/kg), and Soil 4 (∑ PCBs 197.948 ug/kg). The concentrations of total PCBs in the effluent water sample were ∑ 52.99 ug /L. These values were relatively low compared to the guideline limit of 500 μg/kg and those reported in the literature. The toxic equivalency quotient (TEQ) calculated for the samples was Soil1 (0.281 ug/kg), Soil 2 (0.231 ug/kg), Soil 3 (0.252 ug/kg) and Soil 4 (0.217 ug/kg). The toxic equivalency quotient (TEQ) for the water effluent was 0.176 ug/L. The TEQ values obtained were all less than 1, indicating that the levels of PCBs are not yet of toxicity concern to both biota and humans in the study area.