Objective To investigate the indoor radon concentration and its changing trend in northeastern China.Methods We measured indoor radon levels cumulatively for over three months by solid state nuclear track detection in a total of 261 houses in multi-story or high-rise buildings in Shenyang, Changchun, Harbin, Heihe, and Yichun in northeastern China. The measurement lasted one year in Changchun for seasonal changes. Results The average indoor radon concentration in the five cities was 88 Bq/m~3, ranging from 12 to 558 Bq/m~3. The indoor radon concentrations were ≤ 100 Bq/m~3 in75.1% of the houses, and ≤ 300 Bq/m~3 in 97.7% of the houses. The indoor radon concentration increased with the age of buildings. The indoor radon concentration was highest in winter, and it was higher in summer than in autumn and spring.Conclusion The indoor radon concentration in northeastern China increased compared with the data of 1980s and 1990s. It is highest in the winter heating season, and higher in summer than in spring and autumn. Indoor radon exposure deserves attention.

Objective:To conduct radiation detection and dose assessment in selective internal radiotherapy with 90Y resin microspheres for the purpose of providing a reference for radiological protection. Methods:The dose rates from radiotherapy with 90Y resin microspheres were detected in the process of each operation at different distances from the body surface of patients the levels of dose to the persons concerned were compared with the relevant national regulations and standards. Results:The estimated dose rates were 1.12-454 μSv/h during 90Y resin microspheres dispensing and 2.06-58.2 μSv/h during surgical procedure. The dose rates at 0.5 h after surgery were 22.7-64.1 μSv/h at 5 cm and 0.82-2.55 μSv/h at 1 m from three patient′s body surface. Assuming treating 200 patients a year, the annual individual effective dose to the radiation workers was 0.12-1.03 mSv/year. The annual individual effective dose to the public, comforters and carers of patients was 0.02-0.24 mSv/year after release of a patient. Conclusions:During the treatment, nursing and release of patients, the radiation doses to workers, carers and the public are lower than the individual dose limit given in the GB18871-2002 basic standards for protection against ionizing radiation and for the safety of radiation sources and the management target value set by of the relevant medical institutions.

Objective:To evaluate 90Y activity concentration in renal excretions during the first 48 hours after being treated with 90Y resin microspheres seleceive internal radiation therapy(SIRI) and to provide advice on the management of patient excreta after surgery. Methods:After surgery, urine excreted from 3 patients during 0-24 h and 24-48 h was collected respectively, and the 90Y activity concentration in urine was tested and analyzed. Results:90Y radioctivity in the urine excreted from 3 patients after surgery was (1 266±258)kBq/GBq during 0-24 h and (140±106) kBq/GBq during 24-48 h, respectively, and 90Y activity concentration were (640±113) kBq/L during 0-24 h and (53±12) kBq/L during 24-48 h. Conclusions:90Y radioactivity in patient′s urine excreted at 1 d was about 10 times higher than that at 2 d. After surgery, patients can accelerate the reduction of free 90Y activity by increasing excretion. Urine excreted by the patients during hospitalization should be handled in accordance with the requirements of the national standard HJ 1188-2021 Radiation protection and safety requirements for nuclear medicine.

Objective:To analyzes the current status of radiation protection in non-medical sectors, together with the vulnerable spots in the prevention and control of occupational radiation sickness in China in order to provides both technical basis for occupational health management in non-medical radiation sectors and the better protection of occupational health benefits for radiation workers.Methods:The monitoring plan for this survey was worked out on the part of the National Institute for Radiological Protection, China CDC. Survey and monitoring of the current status of radiation protection and occupational health management were, under the monitoring the plan, completed by the relevant agencies of all provincial-level regions for the key industries of non-medical sectors countrywide, involving occupational health monitoring, personal dose monitoring, radiation protection monitoring instruments equipped, and radiation protection monitoring in workplace. Based on the survey result , the deficiencies in radiation protection and occupational health monitoring in non-medical sectors were analyzed.Results:The survey of non-medical sectors was divided into general investigation and detailed monitoring, with the general investigations covering 9 075 non-medical institutions in 31 provincial-level regions across the country. Of them, a total of 4 911 institutions within 329 district-level regions received detailed investigation and radiation protection monitoring. As survey result , the X, γ ambient dose equivalent rates for the institutions using ray-generator are greater than 2.5 μSv/h, about 2.35% of the total, with a maximum of 817 μSv/h. The values for those using radioactive sources were greater than 2.5 μSv/h, about 9.57%, with a maximum of 1 700 μSv/h. The frequencies of personal dose monitoring and occupational health examination were 72.9% and 82.1%, respectively.Conclusions:There is still a gap in radiation protection between the current status and the national regulations and standards in non-medical sectors, so both regulation and management of radiation protection should be further strengthened.

Objective:To explore the existing issues in radiation protection during the treatment of 131I by means of measuring the ambient dose equivalent rate to patients with thyroid cancer and the dose equivalent to the surface of chest of patients during hospitalization. Methods:The ambient dose equivalent rate (peer) was measured by using gamma ray detector for selected 78 patients who received 131I treatment in a hospital 10 min, 1 d, 2 d, 3 d and 5 d after administration with 131I. The measurements were made at distances of 5 cm, 0.5 m and 1 m from the body surface in front, rear, left and right directions. The photoluminescence dosimeter on the chest of the patients was used to measure the effective dose during hospitalization period (6 d). Results:The ambient dose equivalent rate on the surface of chest of patients was up to 4.81 mSv/h 10 min after administration of medicine. The dose equivalent on the surface of chest of patients before discharge ranged 2.6-64.1 μSv/h. The cumulative dose on chest surface during hospitalization was 15.9-58.8 mGy. There was a significant difference in the dose rate at 5 cm from the body surface between 3.7 GBq group and 5.55 GBq group 10 min after medication ( t=-6.11, P<0.05). There was a significant difference in the dose rate at 5 cm from the body surface between male and female groups 10 min after medication ( t=4.52, P < 0.05). There was no significant difference in other groups ( P > 0.05). Conclusions:During the 131I treatment, patients had high level of radiation around them, so it is necessary to strengthen the protection and management of patients and reduce unnecessary exposure to the public.

目的:研究使用驻极体氡探测器测量建材氡222(222Rn)析出的方法.方法:设计、制作建筑材料222Rn析出测量专用密封箱,将驻极体氡探测器与建材样品放入箱中并密封,分不同时间段做累积测量,并于密封箱外部串联一台氡连续测量仪,与驻极体同时测量密封箱内222Rn浓度.通过测量计算密封箱内累积氡浓度,分析比较驻极体法与连续测量法测量222Rn析出率结果的差异及影响因素.结果:驻极体在各累积时间段的测量结果与连续测量方法测量结果比较,其相对百分偏差范围为9.24％～28.8％,且驻极体法24 h的测量结果与连续测量方法百分偏差最小,相对百分偏差为9.24％.结论:驻极体法可以用于建筑材料222Rn析出的测量,且在短周期现场测量方面驻极体氡探测器具有布放方便,测量简便的优势.

Objective:To verify and discuss the consistency and applicability of the semi empirical formula and Monte Carlo simulation method in the radiation shielding calculation for high energy synchrotron radiation source.Methods:The semi empirical formula and Monte Carlo simulation were used to calculate the ambient dose equivalent outside of the shielding.Results:The ratio of Jenkins semi empirical formula result to Monte Carlo simulation result was 111%-153%. The ratio of Sakano semi empirical formula result to Monte Carlo simulation result was 201%.Conclusions:For a single shielding material, the semi empirical formula can be simple and conservative to complete the shielding calculation for high-energy electron accelerator. For a variety of shielding materials, Monte Carlo simulation method should be used.

国家标准《稀土生产场所放射防护要求》（GBZ 139—2019）已经发布,并于2020年4月1日起实施,替代《稀土生产场所中放射卫生防护标准》（GBZ 139—2002）。本文就标准修订的背景、主要修订的内容和依据等进行说明。新标准对于稀土生产场所的放射防护提出了更具体的要求,对保护我国从事稀土矿山开采、选矿和冶炼等工作人员的职业健康发挥重要作用。

目的 通过问卷调查分析核医学科诊疗患者行为学特征及辐射认知状况,为减少公众不必要的照射提供帮助.方法 采用自制的调查问卷调查245名核医学科诊疗患者使用放射性药物后出行方式、住宿、就餐等行为模式以及对辐射的认知等.结果 调查显示,患者中有57.14％在检查后离开医院;检查后离开医院的患者有61.14％采用公共交通方式;28.57％的患者在大众餐馆就餐;有13.06％表示对核医学诊疗注意事项一无所知.结论 患者使用药物后对周围人群的照射不容忽视,应加强核医学科诊疗患者辐射防护认知.

目的 利用放射信息管理系统调查广西医院医疗照射的频次分布.方法 选取在广西开展放射诊疗且具有放射信息管理系统的10家医院,通过放射信息管理系统收集2015年1～12月所有接受计算机X线摄影(CR)检查、数字化X射线摄影(DR)检查和CT检查受检者的性别、年龄、检查类别、检查部位等信息.采用Excel 2013对数据进行统计分析.结果 2015年度进行CR/DR检查和CT检查的总数为1285701人次,其中CR/DR检查的检查次数为887748人次,CT检查的检查次数为397953人次.在CR/DR检查中,检查部位频次前3位的分别为胸部、脊柱、四肢及关节;不同性别患者中,除胸腹部、四肢及关节外,男性其余检查部位的检查次数均低于女性;CR/DR检查者的年龄主要集中在>40岁人群中,除头颅外,其余部位>40岁人群的检查次数均高于≤40岁人群.在CT检查中,检查部位频次前3位的分别为头部、胸部、腹部;不同性别患者中,除脊柱外,男性其余检查部位的检查次数均高于女性;在≤40岁人群中,男性CT检查部位的检查次数均高于女性;CT检查者的年龄主要集中在>40岁人群中,且>40岁人群各部位的检查次数均高于≤40岁人群.结论 不同性别、检查部位的检查频次分布各有特点,但CR/DR检查与CT检查的频次分布均以>40岁人群为主.应该关注>40岁受检者的照射频度,进一步开展医疗照射水平研究,为加强医疗照射防护提供依据.

目的 通过对不同地区5个省的部分临床核医学的调查,获取临床核医学工作场所主要放射性核素的空气中的活度浓度水平,并分析了临床核医学中相关人员的剂量水平,为建立适合我国国情的临床核医学防护规范提供依据.方法 选择5个省份的部分开展临床核医学的医院,对相关的场所进行空气采样,采用无源效率刻度方法进行γ能谱分析,计算得到各场所关注核素的空气中的活度浓度分布水平,估算相关场所中工作人员因放射性核素操作所致的年待积有效剂量.结果 对5个省的9家开展临床核医学的医疗机构核医学相关工作场所进行了采样测量,开展131I治疗的医院工作人员年待积有效剂量最大值为1.67× 10-1 mSv;开展99Tcm诊断的医院工作人员年待积有效剂量最大值为2.80×10-3 mSv;结论不同的医院和场所中核素浓度水平差异较大.正常工作条件下,5个省份的9家医院核医学工作场所的工作人员年待积有效剂量均比国家标准对个人剂量的限值要求低很多.

Objective To study the estimation method of medical exposure frequency in China through the survey of diagnostic radiology and radiotherapy institutions in selected provinces.Methods A survey of medical exposure frequency was carried out involving 557 diagnostic radiology and radiotherapy institutions in 25 provinces.The correlation analysis and multiple linear regression analysis were conducted,with the fitting effects of the models with different variables being compared.Results The total medical exposure frequencies highly correlated with number of outpatient,number of equipment and number of radiation workers (| r| ＞0.5).Representative samples of the daily medical exposure workload were obtained by stratified random sampling from the survey data.Mathematical models were built using the multiple linear regression between total medical exposure frequency and hospital levels,number of outpatients,number of inpatients,number of equipment,and number of radiation workers.The total medical exposure frequency in 2016 was estimated to be 589 million examinations based on the models.In addition,the frequencies of medical procedures were derived using the robust regression and the median regression.Conclusions There are several methods for estimating the total medical exposure frequency.It is desirable to use the stratified random sampling combined with the published statistical and monitoring data.The representativeness of sample is critical.The specification and optimization of models also require further study.

Objective To investigate the effect of iron shield at different depths within main protection wall on the dose rate outside the protection wall. Methods By adopting the FLUKA code, a therapeutic room model was constructed with its primary protective barrier consisting of concrete and iron. In order to obtain its ambient dose equivalent rate distribution, the 250 MeV protons and 220 MeV protons impinging on water phantom were simulated separately. Results With varying depth of iron plate embedded in barrier, the ambient dose equivalent rates in the two simulated conditions differed sinificantly at 30 cm outside the protection wall. The maximum ambient dose equivalent rate(220 MeV:3.42 μSv/h, 250 MeV:6. 39 μSv/h) was more than 2 times higher than the minimum ambient dose equivalent rate ( 220 MeV:1. 75 μSv/h, 250 MeV: 3. 32 μSv/h ) . Conclusions In the design of therapeutic proton accelerator, it is essential to evaluate carefully the location where the iron shield is in main protection wall.

To ascertain the background and frequency of diagnostic medical X-ray procedures in China and provide the basis for regulatory oversight of such applications,a total of 557 medical institutions in 25 provinces or municipalities were surveyed by means of the optimally designed questionnaires and through stratified quota sampling.The numbers of procedures were calculated in terms of the type of procedures and the sex and age of examined patients.As a result,the frequencies of diagnostic X-ray procedures for 2016 in the country were derived using multiple linear regression analysis.The frequency of X-ray diagnosis in 10 provinces of China in 2016 was estimated to be 379-1 228 examinations per 1 000 population.Diagnostic X-ray applications have shown a rapid expansion in 2016 as compared with the period of "9th Five-Year Plan".It is very important to strengthen the regulation of medical diagnostic X-ray applications.

Objective To realize the efficient monitoring of frequency of medical exposure and dose monitoring in Ningbo by means of informatization. Methods Data transmission process and the key elements of frequency of medical exposure and individual dose were investigated. According to standardization principles of data elements, the standardized data elements for frequency of medical exposure and individual dose were determined. On this basis, modules and functions of data receiving platform on the frequency of medical exposure and individual dose in Ningbo were designed. Results Totally 59 data elements on frequency of medical exposure and individual dose were formed. According to their functions, the data receiving platform was divided into the distribution of radiodiagnosis and radiotherapy resources, the frequency monitoring of medical exposure and dose monitoring for permanent residents, and the dose monitoring. Conclusions The establishment of frequency and dose information monitoring platform on medical exposure in Ningbo and the determination of standardized data elements will be conducive to further progress in medical exposure information monitoring in Ningbo.

Objective To validate and discuss the time response correction formula for four types of dosimeters (6150AD6 + 6150AD-b,FH40G + FHZ672E-10,451P ionization chamber and AT1123).Methods The ambient dose equivalent rates shown by survey meters were recorded separately when X-ray emission time was 500,200,100 and 50 ms.The corrected values were obtained by the formula of circuit having a capacitance C and asistance R in series.Results Therewas no correlation between the value measured by AT1123 dosimeter and the time of irradiation.The values by other three kinds of dosimeters obviously varied with the time of irradiation.Conclusions It is not required to make the time response correction for the measured value of ATl123 dosemeter,whereas the values measured by the other three dosimeters could be corrected by the time response correction formula.

Objective To increase the cumulative measurement level of 222 Rn and 220 Rn and ensure the accuracy and reliability of the measurement result . Methods By using improved 222 Rn-220 Rn discriminative detectors ( LD-P detectors) , the radon research group of National Institute for Radiological Protection Chinese Center for Disease Control and Prevention participated with the intercomparison organized by National Institute of Radiological Science ( NIRS) , Japan. Specifically, with the 222 Rn-220 Rn discriminative detectors being sent to Japan, the comparison was completed under different conditions in the 222 Rn chamber and 220 Rn chamber in NIRS. After exposure, the detectors were sent back to our laboratory for etching and analysis, and then measurement result were informed to NIRS. Finally, NIRS returned the exposure reference values of 222 Rn and 220 Rn to our laboratory. Results Under the conditions of high and low levels of 222 Rn, the relative percentage differences ( RPD ) between the measured values and the reference value provided by the NIRS were -12. 0％ and -11. 8％, respectively, while coefficients of variation ( COV) were 3. 0％ and 6. 2％, respectively. Under the conditions of high level and low levels of 220Rn, the relative percentage differences (RPD) between the measured value and the reference value provided by the NIRS were -0. 8％ and -8. 0％, respectively; coefficients of variation ( COV ) were 6. 7％ and 4. 5％, respectively. Conclusions This intercomparison result were categorized by NIRS ( PRD<10％) , with the satisfactory result of LD-P detectors available.

Objective To establish a simple and convenient method and study the feasibility of using gold nanoparticle composites (ssDNA-AuNPs) for colorimetric detection of gamma radiation.Methods The composites ssDNA-AuNPs were prepared by applying the ssDNA to the surface of AuNPs,and then were irradiated with gamma ray with absorbed doses of 0,5,10,20,and 30 Gy,respectively.Subsequently the color change in the solutions were observed simultaneously with absorption spectra being measured.The linear relationship between the ratio of A625/A521 in the absorption spectrum and the absorbed dose was established.Results With the increase of radiation dose,the color of the solutions changed from wine-red to blue-violet gradually,the ratio of A625/A521 in absorption spectra had excellent liner response for absorbed dose ranging from 0 to 30 Gy,and the linear equation was A625/A521 =0.020 6 + 0.303 6 E(R2 =0.991 5).Conclusions The ssDNA-AuNPs synthesized in this experiment can be successfully used for colorimetric detection of gamma absorbed dose,and a simple and convenient method for detection of gamma radiation has been newly established.

国际原子能机构(IAEA)理事会于2011年9 月通过了修改后的《国际辐射防护和辐射源安全基本安全标准》(以下简称新版BSS),并于2014年正式出版了包括中文版在内的文本.此修订过程始于2005年,修改主要基于国际辐射防护委员会(ICRP)的2007 年建议书,替代了1996 年发布的BSS.

Objective To measure the circuit time constants of 4 kinds of radiation survey meters (451P ionization chamber dosimeter,6150AD6 + 6150AD-b dose meter,FH40G + FHZ672E-10 dose meter and AT1123 dose meter) and,to discuss the formula of time response correction and its application.Methods In the condition of continuous exposure of X-ray machine,the ambient dose equivalent rates shown by survey meters were recorded.In order to get the circuits time constant,the least squares fittingmethod was used to fit the data using the time response formula of circuit having a capacitance C and a resistance R in series.Results The relative uncertainty of fitted circuit time constants was higher than 20％ except for 6150AD6 + 6150AD-b dose meter.The relative uncertainty of fitted r was 8％ for 6150AD6 + 6150AD-b dose meter.Conclusions The time required to stabilize the dosimeter readings was 8,5,3 and 2 s,respectively,for the 451P ionization chamber dosimeter,6150AD6 +6150AD-b dose meter,FH40G + FHZ672E-10 dose meter and AT1123 dose meter.The rising trend of their measured values was not fully accordance with the RC circuit time response correction formula.