Yeyao Wu, Mengyun Wu, Jinghua Zhou, Nan Jin, Jing Jin, Fang Yuan, Wei Li
Occupational radiation doses in both hospitals were generally within safe limits. Interventional radiologists remain the highest-risk group by mean dose, while extreme outliers were observed in radiotherapy. The two hospitals showed different dose stability and high-dose event patterns, highlighting the need for targeted protection strategies tailored to each institution's occupational structure and risk profile.
BACKGROUND: This study aimed to investigate 10-year trends in occupational radiation exposure among radiology staff in two tertiary hospitals in Chongqing, China, and to compare exposure patterns across occupational categories, with particular attention to interventional radiology personnel.
METHODS: A repeated cross-sectional study was conducted using annual dosimetry records from radiation workers at two tertiary hospitals (an urban cancer center and a suburban general hospital) from 2015 to 2025. Annual effective doses were measured using thermoluminescent dosimeters. Data were analyzed for overall dose levels, temporal trends, high-dose events (>5, >10, >20 mSv), and occupational differences. Linear regression was used to evaluate temporal trends.
RESULTS: The number of radiation workers increased significantly in both hospitals (both p < 0.001). Overall mean annual doses ranged from 0.24 to 0.69 mSv, well below the national limit of 20 mSv. Interventional radiology staff consistently had the highest mean doses among all categories in both hospitals. However, the highest maximum doses were from radiotherapy staff in the urban cancer center (45.42 mSv in 2017). The suburban general hospital showed higher dose variability, more frequent high-dose events (19 vs. 5 records), and a significant increasing trend in interventional radiology mean doses (β = 0.08 mSv/year, 95% CI: 0.04-0.12, p = 0.003), whereas the urban cancer center maintained stable low doses with no significant temporal trend. These inter-hospital differences reflect a combination of hospital type, service mix, and management practices, and should not be attributed solely to urban-suburban location.
CONCLUSION: Occupational radiation doses in both hospitals were generally within safe limits. Interventional radiologists remain the highest-risk group by mean dose, while extreme outliers were observed in radiotherapy. The two hospitals showed different dose stability and high-dose event patterns, highlighting the need for targeted protection strategies tailored to each institution's occupational structure and risk profile.