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Objective:To summarize the levels of individual dose to radiation workers in Shandong province from 2016 to 2020, and to analyze the trends in their change in order to provide scientific basis for radiation workers′ health management.Methods:The experimental detection and quality control were carried out in compliance with the national standards Specifications for individual monitoring of occupational external exposure (GBZ 128-2019) and the Testing criteria of personnel dosimetry performance for external exposure (GBZ 207-2016). The result of the personal dose monitoring of occupational external exposure of all radiation workers monitored by the Centers for Disease Control and Prevention in 16 cities of Shandong province were retrospectively analyzed by using SPSS 23.0 software.Results:The total number of monitored workers were 25 523 with an average annual individual effective dose of 0.28 mSv. There were statistically significant differences among radiation workers in different years ( H= 2 815.91, P<0. 001). The average annual individual effective dose showed an upward trend followed by a downward trend. The average annual effective dose of 0.55 mSv for nuclear medicine radiation workers in medical applications was the highest, with statistically significant differences among different occupational radiation workers ( H=310.37, P<0.001). The average annual effective dose of 0.37 mSv for radioactivity logging workers in industrial applications was the highest, with statistically significant differences among different occupational radiation workers ( H=448.07, P<0. 001). The average annual effective dose to radiation workers in medical applications was higher than in industrial applications ( Z = -14.93, P<0.001). Conclusions:The average annual effective dose to nuclear medicine radiation workers in medical applications and logging radiation workers in industrial applications are relatively high. There would be a push to furthe improve workplace protection measures and strengthen the management and supervision of radiological workers.
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Objective To preliminarily compare 6LiF-7LiF and CR39 in individual neutron dose monitoring, and to provide a reference for improving individual neutron dose monitoring. Methods According to the GBZ 128-2019, 26 radiation workers from 7 institutions received individual neutron dose monitoring with 6LiF-7LiF and CR39 at the same time. The monitoring results were analyzed. Results For most of the workers, the personal neutron dose equivalent Hp(10) was less than the minimum detectable level. The results with the two monitoring methods differed in 6 of 26 workers. Conclusion Both 6LiF-7LiF and CR39 monitoring methods can be used for individual neutron dose monitoring for radiation workers, but the difference between 6LiF-7LiF and CR39 (in threshold energy, energy response, etc.) should be considered so that different types of radiation workers receive appropriate individual neutron dose monitoring.
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Objective To analyze and compare the data of Yunnan Center for Disease Control and Preventionin national individual dose monitoring ability assessment for external exposure in 2017—2019 and summarize the assessment experience, and to improve monitoring ability and quality. Methods Ability assessment preparation was carried out according to the requirements of The National Comparison Scheme for Individual Dose Monitoring Ability, and blind samples of individual dosimeters were sent. After the blind samples were measured in the laboratory, the results were judged according to the judgment methods in the Testing Criteria of Personnel Dosimetry Performance for External Exposure (GBZ 207—2016) and the requirements of the assessment scheme. Results In 2017, there was a single-group performance of 0.02-0.08 and a comprehensive performance of 0.06, and the results were judged to be qualified. In 2018, there was asingle-group performance of −0.01 to 0.08 and a comprehensive performance of 0.05, and the results were judged to be excellent. In 2019, there was asingle-group performance of −0.13 to −0.04 and a comprehensive performance of 0.08, and the results were judged to be qualified. Conclusion The individual dose monitoring system in our laboratory runs stably, and the monitoring results are accurate and reliable. The quality control measures are effective and feasible.
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Objective To investigate and analyze the cause of the abnormal results in the individual dose monitoring conducted by this laboratory from 2014 to 2017. Methods Radiologic workers wear personal thermoluminescent dosimeters to monitor the individual dose equivalent HP(10). A statistical analysis is conducted on the results above the investigation level. Results During the time when our individual dose monitoring was conducted from 2014 to 2017, this laboratory had detected 69 person-time abnormal results in 40 workplaces, of which 83% occurred in the profession of diagnostic roentgenology. 54% of the dose level range from 1.25 to 5.00 mSv. The main causes of the abnormal results include improper wearing of personal dosimeters (67%), unknown causes (20%), increased workload (10%) and equipment maintenance (3.0%)etc. Conclusion Radiation workplaces should enhance the management of radiologic workers, improve their trainings on radiation protection and raise their protection awareness.
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Objective To analyze the abnormal results of individual dose monitoring of some radiation workers in Chengdu from 2016 to 2018, so as to take corresponding measures to avoid similar abnormal situations. Methods The individual dose was monitored by thermoluminescence method, and the monitoring results were analyzed by spss19.0 statistical software. Results From 2016 to 2018, the number of people with abnormal dose was basically the same, and there was no significant difference in the number of people with abnormal dose in different years (P > 0.05); the number of people engaged in diagnostic radiology with abnormal personal dose accounted for 75.96%; the first reason for the abnormal personal dose was that "the personal dosimeter had been left in the radiation workplace", accounting for 92.55%. Conclusion The main reason for the abnormal results is that the dosimeter is not worn properly, so the management should be further strengthened.
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Objective In 2019, Laboratory of Shanghai Chongming Center for Disease Control and Prevention participated in national assessment of individual dose monitoring capability. By analyzing the results, this report summarizes the experience and shortcomings that will help improve the individual dose monitoring capability of the laboratory. Methods According to the requirements of the national assessment scheme for individual dose monitoring capacity in 2019, the assessment process and results were sorted out and analyzed one by one. Results The single group performance deviations(Pi values)between the measured values and references of the five groups were -0.04, -0.07, -0.05, -0.04 and -0.06, respectively. The overall bias(B value)of all groups was 0.003. According to the judgment standards, both the single group performance and overall performance were all qualified. Conclusion The individual dose monitoring system of the laboratory meets the requirements of the relevant national standards. The individual dose monitoring capability can be further improved by strengthening the quality control of the relevant procedures of the assessment.
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Objective:To analyze distributions of dose range, occupational category, and causes of abnormal dose values from individual dose monitoring of radiation workers and to provide recommendations for improving the quality of individual monitoring data and occupational health management in medical institutions.Methods:The data of individual dose monitoring result exceeding 1.25 mSv in a single monitoring cycle, collected by Occupational Health System for Radiology Facilities’ on National Radiological Health Information Platform, was analyzed.Results:A total of 1 113 abnormal dose values were detected in 31 provinces in 2020, with an abnormal rate of 2.48‰, of which workers of diagnostic radiology and interventional radiology accounted for 68.01% and 18.78%, respectively. The dose distribution of abnormal dose values was mainly between 1.25 and 5 mSv. The abnormal dose values were mainly caused by improperly wearing or using personal dosimeters, accounting for 63.88%. Workers for whom the dose values was abnormal due to increased workload accounted for 12.32%, with an average annual individual dose of 5.14 mSv. There was no statistically significant difference in annual individual dose among radiation workers between different occupational groups( P>0.05). Conclusions:Education and training on radiation protection for radiation workers should be strengthened, and a specific and feasible system for radiation protection management, as well as a reward and punishment system, should be established in order to reduce the occurance of the improper wearing of personal dosimeters. Great attention should be paid to occupational exposure of workers in diagnostic radiology and interventional radiology, and a work shift system should be conducted to reduce individual dose levels. It is recommended that standard verification procedures for abnormal dose values from individual dose monitoring should be developed to improve the quality of individual monitoring data.
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Objective To standardize the uncertainty assessment work of nationwide radiological technical service institutions in respect to individual dose monitoring, to enhance the relevant capability and to ensure the quality of assessment. Methods The 2017 nationwide individual dose monitoring assessment for external exposure was carried out, and the problems found in uncertainty assessment in the submitted reports were analyzed and summarized. Results A total of 259 personal dose monitoring technical service institutions submitted their completed assessment reports and verification/calibration certificates. The accuracy rate of Class A uncertainty evaluation was 20.8％ and that of class B 55.2％ for calibration, 50.6％ for energy response, 25.5％ for angle ring and 51.4％ non-linearity response, respectively. The accuracy rate of effective digits of the estimated values and their uncertainty was 30.4％. Conclusions The ability of these individual dose monitoring institutions to assess uncertainties remains to be improved. It is recommended to enhance systematic training of the institutions with respect to uncertainty evaluation and to standardize the assessment reports, so as to improve the accuracy of the monitoring result and the quality of accuracy reporting.
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Objective To normalize the individual dose monitoring for nationwide radiological workers and to improve individual dose monitoring ability of radiological health monitoring service institutions. Methods The 2017 annual intercomparison was carried out of nationwide external radiation individual dose monitoring result, with summary and analysis completed. Results A total of 283 monitoring service institutions were involved in the 2017 annual intercomparison. Of them, 249 were qualified, 45 excellent and 34 unqualified. The excellent rate was 15.9％ and the pass rate 88.0％. Conclusions Most of individual dose institutions could meet better the requirements by the intercomparison, but some deviated from the references to some degree. It is necessary to strengthen the laboratory operation and standardize data processing and to improve the accuracy end precision of measurement result .