Assessment of Ambient Radiation Dose Levels in Selected Sections of the Conventional X-Ray Facility in FMC Jalingo, Taraba State, Nigeria

Abstract

This study evaluated ambient radiation dose rates under routine operational conditions at the Conventional X-ray Unit of the Federal Medical Centre (FMC), Jalingo, Nigeria, to establish a radiological baseline and assess structural shielding adequacy. Using a factory-calibrated GMC-320 Geiger-Müller detector positioned 1.0 m above the floor, in situ measurements were conducted across five key locations over 30 working days during peak hours (10:00 a.m. to 2:00 p.m.). The mean ambient radiation dose rates ranged from 0.183 ± 0.021 µSv/h in the waiting area (5.0 m from the source) to 0.258 ± 0.012 µSv/h inside the X-ray room (0.0 m), yielding an overall structural baseline of 0.216 ± 0.027 µSv/h. The measured dose rates exhibited a progressive, inverse relationship with distance from the X-ray tube. Extrapolated annualized continuous exposure estimates ranged from 1.603 mSv/year in the waiting area to 2.263 mSv/year in the examination room, with an overall average of 1.889 ± 0.239 mSv/year. While these values reflect conservative, worst-case continuous exposure scenarios, the elevated dose rates in occupied adjacent spaces like the control room (1.901 mSv/year) and dressing room (1.865 mSv/year) indicate the necessity for formal, occupancy-weighted risk adjustments. These findings provide a vital empirical baseline for optimizing local structural barriers and ensuring strict adherence to public and occupational radiation protection standards.