Application of Geostatistical Kriging Model in Assessing Exposure to Background Ionizing Radiation and its Radiological Hazard Indices

Abstract

Background ionizing radiation from natural sources is a pervasive environmental factor that poses significant health risks. Rural assessment of developing nations is often neglected, due to perceived lower radiation risk and limited industrialization. This study therefore addresses this gap by measuring the terrestrial gamma dose rates, estimate the radiological hazards, and predict the gamma dose rates at unobserved locations using Kriging Model in Ogbomoso South Local Government, a rural region within Oyo State, Nigeria. A systematic random sampling was conducted within 10 administrative wards. In-situ gamma dose rate measurements were taken using a Radex, RD 1503 dosimeter and ArcMap was used to generate spatial map. Terrestrial average gamma dose rates (ADR) ranging from 0.122 to 0.139 μSvh-1, with an overall average of 0.132 μSvh-1, which is below the global average of 0.274 μSvh-1. The estimated annual effective dose equivalent ranged from 0.213 to 0.243 mSvy-1, averaging 0.231 mSvy-1, significantly below permissible limits of 1 mSvy-1. The spatial map of ADR distribution, ranged from 0.085 to 0.179 μSvh-1. The study concludes that current radiation exposure level poses no significant radiological hazard. It recommends regular monitoring program to track changes over time with the data considered as baseline for Ogbomoso South local Government.

Keywords

• Background ionizing radiation
• Geostatistics
• Kriging model
• Radiological indices