Polycyclic aromatic hydrocarbon concentrations in soil of three communities in Rivers State

Abstract

The study was conducted in three communities in Rivers State. These communities include Okochiri community in Okrika, Mgbuodohia in Obio-Akpor and Chokocho in Etche. Soil at two different depths were sampled on a composite basis using EGASPIN 2018 procedures, extracted and analyzed for sixteen priority PAHs using US EPA 8270 (2014) procedures. Studies show the total concentration of PAHs in soil sample taken from Okochiri community in Okrika at depths of 0 - 15 cm and 15 - 30 cm was found to be 145.32 mg/kg and 101.6 mg/kg during the dry season respectively but in the wet season the total concentration was found to be 607.08 mg/kg and 242.46 mg/kg at the two depths. In Mgbuodohia, the dry season result for the two depths, showed a total concentration of 14.68 mg/kg and 27.33 mg/kg and, 16.12 mg/kg and 14.94 mg/kg in the wet season. In Chokocho, the result showed a total concentration of 4.33 mg/kg and 252 mg/kg in the dry season and 23.87 mg/kg and 10.23 mg/kg in the wet season. Result showed a higher concentration of PAHs in the tops soil (0- 15 cm) compared to the subsoil at the depth (15 - 30 cm). The total PAHs concentration was consistently higher in the wet season than in the dry season. The concentration of PAHs was found to be majorly higher in the topsoil than the subsoil both in the dry and wet season. Diagnostic ratios reveal major source to be petrogenic. The concern for the environment and humans should prompt important stakeholders to take measures that will lead to mitigate the impact of these toxic chemical.