Title: Natural Background Ionizing Radiation In Ogoniland: A Post-Oil Spill Radiological Risk Evaluation Of Terrestrial Gamma Exposure And Stochastic Health Effects
Authors: Omotinugbon. D. Olufemi, Osu C. I. & Balogun A.O
Volume: 9
Issue: 11
Pages: 44-55
Publication Date: 2025/11/28
Abstract:
The study examines Natural background ionizing radiation in Ogoniland: A post-oil spill radiological risk evaluation of terrestrial gamma exposure and stochastic health effects. Calibrated dose rate surveys were performed in twenty communities across Tai and Khana Local Government Areas (LGAs) of Ogoniland to establish the first high resolution baseline of background ionizing radiation (BIR) and associated health indices after six decades of crude-oil perturbation. Mean outdoor exposure rates were 0.0046 ± 0.0007mR h?¹ (Tai) and 0.0049 ± 0.001mRh?¹ (Khana), translating to absorbed dose rates of 40.02 ± 6nGyh?¹ and 42.63 ± 9nGyh?¹ both 52 % below the 89nGyh?¹ UNSCEAR world average. Annual effective dose equivalents averaged 0.061 ± 0.01 mSv (Tai) and 0.065 ± 0.01 mSv (Khana), less than 7% of the 1.0mSv global outdoor norm. Excess lifetime cancer risk (ELCR) estimates of (0.215 - 0.229) × 10?³ lie 21% under the 0.29 × 10?³ international benchmark, while organ specific effective doses to testes (0.043mSvy?¹) and ovaries (0.030mSvy?¹) remain less than 4% of the 1mSvy?¹ tissue tolerance limit. Contour maps reveal a homogeneous low rate background ionizing radiation, confirming negligible radiological hazard for residents. The dataset serves as a reference for future TENORM monitoring and regional radiological protection policy.