A Multi-Center Assessment of Occupational Radiation Exposure Levels Due to Radio-Diagnostic Activities in Four Specialist Hospitals in Northwestern Nigeria

Medical applications of ionizing radiation, such as X-rays, fluoroscopy, mammography, and computed tomography, are indispensable for diagnosis and treatment but pose potential health risks to occupational workers. Concerns about ionizing radiation exposure highlight the critical need for effective radiation protection and continuous monitoring. This study evaluated occupational radiation exposure among workers in radio-diagnostic activities across four specialist hospitals in Northwestern Nigeria over a 12-month period (March 2024–March 2025). Using 20 thermo-luminescence dosimeters (TLDs) distributed across the centers, quarterly readings were processed at the Centre for Energy Research and Training (CERT), Zaria, to determine annual surface skin dose (Hp(0.07)) and deep skin dose (Hp(10)). The mean annual Hp(0.07) and Hp(10) across all hospitals were 1.03 mSv and 2.16 mSv, respectively, with individual doses ranging from 0.11 mSv to 1.70 mSv for Hp(0.07) and 0.14 mSv to 3.92 mSv for Hp(10). One-way ANOVA revealed no statistically significant differences in mean annual doses among the four hospitals (F=0.335, p=0.800 for Hp(0.07); F=0.327, p=0.806 for Hp(10)). These exposure levels were consistently well within national (NNRA: 20 mSv/year) and international (ICRP: 5 mSv/year effective dose) limits, indicating effective radiation protection. The observed consistency across centers underscores the importance of continued personnel monitoring and adherence to the ALARA principle to minimize stochastic effects.