Mailed dose record review of occupational dosimetry records among Japanese medical radiation workers: the OREMS Study

Occupational dose records in Japan are retained by employers, with no national registry, complicating epidemiological exposure assessments. In the Epidemiological Study on Occupational Radiation Exposure in Medical Staff, the feasibility of a mailed dose record review was evaluated among participants who underwent occupational radiation health surveillance (ORHS) at six annual conferences (November 2020-October 2024). Dose information was obtained for 182 individuals (44.9% of eligible participants). The median cumulative effective dose was 2.3 [25th, 75th percentile: 0.3, 11.7] mSv, and median cumulative duration was 8.5 [3.8, 19.8] years. For the fiscal year prior to ORHS, annualized median values were 0.1 mSv for effective dose (E), 0.6 mSv for equivalent dose to the lens of the eye (Heye), and 0.6 mSv for equivalent dose to the skin (Hskin) (values below the detection limit were set to 0.0 mSv), presented descriptively to characterize data properties in this feasibility study. Interventional radiology physicians tended to show higher cumulative and annualized doses than neuro-spine physicians in this descriptive feasibility analysis.