Assessment of occupational radiation exposure in academic office environments: a systematic study of the faculty of science, University of Maiduguri, Nigeria

Assessing occupational radiation exposure in academic institutions is crucial for ensuring compliance with international safety standards and mitigating risks associated with natural background radiation. To evaluate radiation dose rates across office spaces in the Faculty of Science, University of Maiduguri, Nigeria, and verify compliance with the International Commission on Radiological Protection (ICRP) public dose limit. A cross-sectional survey measured gamma radiation at 21 office locations using the RadEye G-10 gamma survey meter. A three-zone protocol recorded dose rates (μSv/hr) one meter outside doors, at thresholds, and one meter inside offices. Geographic coordinates were logged via GPS, and statistical analyses (ANOVA, correlations, K-means clustering) assessed dose variations and spatial patterns. Annual doses were calculated using 2000 working hours/year. The mean dose rate was 0.19 ± 0.05 μSv/hr. Annual doses ranged from 0.24–0.52 mSv (external), 0.24–0.68 mSv (threshold), and 0.24–0.68 mSv (internal), with location A15 reaching 0.68 mSv/year (68% of ICRP limit) in threshold/internal zones. All doses were below the ICRP 1 mSv/year public limit. The Radiation Exposure Index (REI) and K-means clustering identified three Elevated-risk locations (A12, A15, A21; 0.50–0.70 mSv/year). Radiation levels comply with ICRP standards, but three locations warrant quarterly monitoring and material investigations (e.g., granite content). The three-zone protocol and REI provide a replicable framework for radiation safety assessments in academic settings, particularly in developing nations.