核医学场所空气中^(131)I浓度监测及工作人员内照射剂量评价探讨  

Evaluation of internal doses to workers and monitoring of^(131)I concentration in air in nuclear medicine workplaces

作　　者：林宝 孙桂湘 张超宇 翟贺争[4] 郭勇 张树义 刘少龙 郭子轩 程晓军 Lin Bao;Sun Guixiang;Zhang Chaoyu;Zhai Hezheng;Guo Yong;Zhang Shuyi;Liu Shaolong;Guo Zixuan;Cheng Xiaojun(Henan Province Health Hygiene Technical Supervision Center,Zhengzhou 450046,China;Zhengzhou Health Supervision Bureau,Zhengzhou 450053,China;Henan Jiadehengli Technology Co.,Ltd,Zhengzhou 450001,China;Institute of Radiation Medicine,Chinese Academy of Medical Sciences,Tianjin 300192,China;Third People′s Hospital of Henan Province(Henan Hospital of Occupational Disease),Henan Key Laboratory of Medicine on Radiobiology and Epidemiology,Zhengzhou 450052,China)

机构地区：[1]河南省卫生健康技术监督中心,郑州450046 [2]郑州市卫生计生监督局,郑州450053 [3]河南嘉德恒立科技有限公司,郑州450001 [4]中国医学科学院放射医学研究所,天津300192 [5]河南省第三人民医院(河南省职业病医院)河南省辐射生物与流行病学医学重点实验室,郑州450052

出　　处：《中华放射医学与防护杂志》2023年第9期717-723,共7页Chinese Journal of Radiological Medicine and Protection

基　　金：河南省医学科技攻关计划项目(LHGJ20190815)。

摘　　要：目的了解医疗机构^(131)I治疗工作场所空气中^(131)I核素的活度浓度水平,探讨通过空气采样方法估算工作人员内照射剂量的方法并分析其影响因素。方法选取郑州市10家开展^(131)I核素治疗的工作场所,采用空气采样方法采集^(131)I治疗工作场所中放射性气溶胶,用高纯锗γ能谱仪进行γ放射性核素测定并推算工作场所空气中^(131)I核素的活度浓度水平,根据测量结果和现场调查结果估算放射工作人员因^(131)I核素吸入导致的内照射剂量。结果19个分装间空气样品的^(131)I活度浓度为0.087~570 Bq/m^(3),平均为(51.04±128.58)Bq/m^(3);11个病房空气样品的^(131)I活度浓度为0.162~54.6 Bq/m^(3),平均为(7.97±15.89)Bq/m^(3)。根据GBZ 129-2016《职业性内照射个人监测规范》推荐的典型工作时间估算,放射工作人员由于吸入^(131)I核素导致的年待积有效剂量范围为2μSv~10 mSv,平均为(0.61±1.80)mSv,年有效剂量均未超过国家标准所规定的剂量限值。结论郑州市10家医疗机构核医学工作场所中^(131)I核素活度浓度较高的样品多分布在甲状腺癌住院患者较多、核素操作量较大的三甲医院,由此导致的工作人员内照射剂量不容忽视。根据空气样品的测量结果估算内照射剂量带有很大不确定度,但空气采样方法可及时发现异常或事故情况下的放射性污染,为工作人员开展体外直接测量和内照射评价提供预警。Objective To asscentain the^(131)I activity concentration in^(131)I treatment workplaces and to explore the method of estimating the internal dose to workers by air sampling and to analyze its influencing factors.Methods Air sampling method was used to collect aerosols containing radioactivity in 10 randomly selected workplaces in Zhengzhou where^(131)I therapy was performed.Aactivity concentration of^(131)I in treatment workplace was measured for gamma emitters by gamma-ray spectrometry.The internal dose due to^(131)I inhalation was estimated based on measurement result and field investigation result.Results The activity concentration of^(131)I in air samples from 19 subpacking rooms ranged from 0.087 to 570 Bq/m^(3),with an average of(51.04±128.58)Bq/m^(3).Those from 11 wards ranged from 0.162 to 54.6 Bq/m^(3),with an average of(7.97±15.89)Bq/m^(3).In terms of the work hours recommended by the national standard GBZ 129-2016 Specifications for individual monitoring of occupational internal exposure,the estimated annual effective dose to radiation workers due to the inhalation of^(131)I ranges from 0.002 to 10 mSv,with an average of(0.61±1.80)mSv,below the dose limit specified in the national standards.Conclusions The samples with high^(131)I activity concentration in nuclear medicine workplaces of 10 medical institutions selected in Zhengzhou are mostly distributed in tertiary class hospitals operating large amount of radionuclide with large numbers of thyroid cancer patients adimitted.The result ing internal dose to radiation workers cannot be ignored.Estimating the internal dose based on the measurement result of air samples has a large uncertainty.However,air sampling method can promptly detect radioactive contamination in case of abnormal events or accidents,providing early warning for workers to carry out dose measurement from external exposure and internal exposure assessment.

关 键 词：^(131)I 空气采样 活度浓度 内照射 

分 类 号：R144[医药卫生—公共卫生与预防医学]