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Research Article Volume 10 Issue 2
Exposure assessment of natural background ionizing radiation and its potential health effects in diagnostic radiology department
Garba II, Samaila B, Maidamma B, Rilwanu MD, Jega AM
Received: March 20, 2026 | Published: May 19, 2026
Citation: Garba II, Samaila B, Maidamma B, et al. Exposure assessment of natural background ionizing radiation and its potential health effects in diagnostic radiology department. Material Sci & Eng Int J. 2026;10(1):63-67. DOI: 10.15406/mseij.2026.10.00269
Abstract
Background: The back ground natural ionizing radiation is the biggest source of ionizing radiation exposure to humans. In diagnostic radiology environments, healthcare workers may experience additional exposure due to scattered radiation from imaging equipment. Continuous monitoring is therefore essential to ensure compliance with international radiation protection standards. Objective: This study assessed ambient natural background ionizing radiation levels and associated excess lifetime cancer risk (ELCR) among healthcare workers in the Diagnostic Radiology Department of the Federal Teaching Hospital, Birnin Kebbi, Nigeria. Methods: A cross-sectional observational study design was adopted. Ambient dose rates were measured using a calibrated Geiger–Müller survey meter at 1 m above floor level across computed tomography (CT), X-ray, fluoroscopy, and mammography buildings. Measurements were conducted under equipment “OFF” and operational conditions at predefined staff-occupied and patient-accessible locations. Annual effective dose (AED) was calculated using standard occupancy factors in accordance with recommendations of the International Commission on Radiological Protection and the United Nations Scientific Committee on the Effects of Atomic Radiation. ELCR was estimated using ICRP risk coefficients (0.05 Sv⁻¹). Results: The CT unit recorded the highest mean ambient dose rate (0.20 µSv/h), corresponding to an annual effective dose of 1.41 mSv/year and ELCR of 4.93 × 10 ⁻³. Non-CT areas (X-ray, fluoroscopy, and mammography units) showed a lower mean dose rate of 0.14 µSv/h, annual effective dose of 0.95 mSv/year, and ELCR of 3.32 × 10 ⁻³. CT environments demonstrated a 43–49% increase in radiation dose compared with non-CT buildings, due to the fact that the CT complex was newly constructed. The highest localized readings were observed in CT preparation (0.34 µSv/h) and exposure rooms (0.30 µSv/h), while administrative and waiting areas recorded comparatively lower values (0.11–0.13 µSv/h). All estimated occupational doses remained below the recommended limit of 20 mSv/year averaged over five years as stipulated in ICRP Publication 103. Conclusion: Although occupational exposures in the studied facility remain within internationally accepted limits, CT environments exhibit significantly elevated ambient radiation levels compared to other diagnostic units. Continuous environmental monitoring, periodic shielding assessment, and optimization of occupancy patterns are recommended to maintain exposures As Low as Reasonably Achievable (ALARA), consistent with guidelines of the International Atomic Energy Agency and the International Commission on Radiological Protection.
Keywords: natural background radiation, occupational exposure, computed tomography, annual effective dose, excess lifetime cancer risk, diagnostic radiology and radiation protection
©2026 Garba, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.