Abstract: Objective To analyze the individual dose level of occupational external radiation of radiation workers in medical institutions in Zhenjiang City,provide a reference for the radiation protection management of medical institutions in Zhenjiang City and protect the health of radiation workers. Methods According to the GBZ 128-2019 Code for Personal Monitoring of Occupational External Radiation,the thermoluminescence dosimetry system was used to monitor the personal dose of external radiation to radiation workers. The radiation workers who were monitored four times a year were included in the study,the annual effective dose monitoring results of radiation workers in different years,occupational categories and levels of hospitals were analyzed,and the causes of abnormal dose were analyzed. Results A total of 4 900 individuals were collected for dose monitoring,and the number of people monitored increased year by year,with a total continuous monitoring rate of 80.9%. The median annual effective dose per capita of radiation workers was 0.84 mSv. 70.3% of radiologists had an annual effective dose <1.0 mSv. There was statistically significant difference in the per capita annual effective dose among different years（H=342.267,P<0.01）,the per capita annual effective dose in 2022 and 2023 was lower than that in 2019,2020,and 2021（all P<0.05）,and the per capita annual effective dose in 2021 was lower than that in 2019 and 2020（all P<0.05）. There was statistically significant difference in the per capita annual effective dose among radiation workers in different occupational groups（H=99.583,P<0.01）. The median annual effective dose per capita of interventional radiology workers was lower than that of diagnostic radiology and dental radiology（both P<0.05）. There was no statistically significant difference among other occupational groups. There was a statistically significant difference in the median per capita annual effective dose value among different levels of hospitals（H=32.980,P<0.01）,and the per capita annual effective dose value of radiation workers in secondary hospitals was lower than that of tertiary hospitals and primary and ungraded hospitals,with statistically significant difference（P<0.05）. From 2019 to 2023,a total of 457 people had ≥1.25 mSv in a single monitoring cycle,accounting for 2.10% of the total number of monitoring person-times. There were 71 cases in which the monitored dose >5 mSv,and the abnormal dose was mainly due to the personal dosimeter being misplaced in the irradiation range（48.8%）. Conclusions From 2017 to 2019,the monitoring value of external radiation dose of radiation workers in medical institutions in Zhenjiang City is far lower than the national standard. It is necessary to continue to strengthen supervision,standardize personal dosage wearing standards,and enhance continuous monitoring. More attention should be paid to grassroots health institutions in radiation health management to ensure the health of radiation workers.

Key words: Medical institutions, External radiation individual doses, Continuous monitoring, Abnormal dose