Authors: Stephen Ovie Ewagba, Orute Destiny, Ezekiel O. Agbalagba, Alex Orduvwe Teghware, Erienu Obruche Kennedy
Abstract: This study evaluated the radiometric characteristics of soils from selected OML 30 oil fields and host-community environments in Delta State using natural radionuclide measurements and the RESRAD-BIOTA code. The activity concentrations of ^40K, ^226Ra and ^232Th were determined for the investigated soil samples, while radium equivalent activity (Raeq) was used to provide an integrated measure of the concentrations of the radionuclides. The results showed considerable spatial variation across the studied oil fields. ^40K concentrations ranged from 219.25 to 553.65 Bq kg⁻¹, ^226Ra from 26.20 to 55.30 Bq kg⁻¹, and ^232Th from 17.35 to 38.10 Bq kg⁻¹. Kokori recorded the highest concentrations of all three radionuclides, whereas Otorogu generally recorded the lowest values. The calculated Raeq values ranged from 69.60 to 152.40 Bq kg⁻¹ and were below the reported recommended value of 370 Bq kg⁻¹. RESRAD-BIOTA version 1.8 was subsequently applied to estimate external, internal and total radiation doses to terrestrial plants and animals. The modeled results demonstrated spatial differences in biota dose, with Kokori recording among the highest total doses. Overall, the findings provide evidence of spatially variable natural radioactivity in the investigated oil-field soils and establish a radiometric baseline for continued environmental monitoring.
DOI: http://doi.org/10.5281/zenodo.23056985
