Background Radiation Levels of Residential Buildings within Selected Oil and Gas Eploration Communities in Andoni LGA of Rivers State

Background radiation is a persistent component of the environment, originating from natural and artificial sources. This study assessed background radiation levels in residential buildings across selected oil and gas exploration communities in Andoni Local Government Area (LGA), Rivers State, Nigeria. A cross-sectionalprospective survey was conducted in 350 residential buildings across 35 communities in seven districts of the LGA. Indoor and outdoor radiation levels were measured in situ using a calibrated Radiation Alert Ranger dosimeter held one meter above ground level. Three readings were taken at each location and averaged. Annual indoor and outdoor effective dose rates were calculated using standard occupancy factors. Data were analyzed using Statistical Package for Social Sciences, SPSS, version 21.0 (IBM Corp. Armonk, NY, USA, 2012). Data were described using mean ± SD, frequency tables and bar charts. One way analysis of variance (ANOVA) was used to compare mean background radiation levels among the communities and within strata while mean indoor and outdoor effective dose with recommended dose limits recommended by international regulatory bodies. Results showed slight variations in background radiation across districts. Agwutobolo recorded the highest effective dose (0.2836 mSv/y) and Unyeada the lowest (0.1787 mSv/y). The lungs received the highest organ absorbed dose (0.034032 mSv/y), while the thyroid received the lowest (0.007148 mSv/y). Excess Lifetime Cancer Risk (ELCR) ranged from 1.13 × 10⁻³ to 7.13 × 10⁻⁴. All measured values remained well below the public exposure limit of 1.0 mSv/y recommended by the International Commission on Radiological Protection (ICRP) and the global average of 2.4 mSv/y reported by UNSCEAR. The findings indicate that residents of these oil-producing communities are not at significant radiological risk from background radiation levels. The study provides a useful baseline for continuous environmental monitoring and can inform policy-making on radiation protection and community health management in oil-producing regions. Key words: Background radiation, Outdoor annual dose, radiation protection