广东省8家医院核医学工作人员碘-131内照射水平分析

Analysis of 131I radiation internal exposure in nuclear medicine staff of eight hospitals in Guangdong Province

目的了解广东省开展核素治疗核医学工作人员(NMWs)内照射情况,评估其内照射风险。方法采用方便抽样法,选择广东省8家医院的61名NMWs为研究对象,采用体外直接测量法,测量右上臂三角肌(本底)和甲状腺位置的0.364 MeV全能峰计数率,计算其甲状腺的碘-131(^(131)I)活度,评估其内照射水平。结果61名NMWs中,3家医院的4名NMWs甲状腺中检出^(131)I,检出率为6.6%。该4人甲状腺中^(131)I活度中位数及其第0~100百分位数[M(P_(0)~P_(100))]为42.9(35.1~47.1)Bq;假设监测周期为30 d,估算其甲状腺单次待积有效剂量M(P_(0)~P_(100))为0.014(0.011~0.015)mSv,内照射年剂量M(P_(0)~P_(100))为0.162(0.132~0.180)mSv/a。结论广东省8家医院NMWs内照射水平符合年有效剂量限值(≤20.000 mSv/a)的要求;但仍需重视NMWs的内照射防护,采取合理的防护措施降低工作人员内照射风险。

Objective To evaluate the internal exposure levels and risk in nuclear medicine workers(NMWs)engaged in radionuclide therapy in Guangdong Province.Methods A total of 61 NMWs from eight hospitals in Guangdong Province were selected as the study subjects using the convenient sampling method.The 0.364 MeV full energy peak efficiency was detected in deltoid muscle of right upper arm(as background)and thyroid gland by in vitro direct measurement method,and the iodine-131(^(131)I)activity in thyroid gland was calculated to evaluate the internal irradiation level.Results Among the 61 NMWs,^(131)I was detected in the thyroid gland of four nuclear medical staffs in three hospitals,and the detection rate was 6.6%.The median and 0-100 percentile[M(P_(0)-P_(100))]of thyroid131I activity were 42.9(35.1-47.1)Bq.When assuming that the monitoring period was30 days,the M(P_(0)-P_(100))of single committed effective dose in thyroid gland was 0.014(0.011-0.015)mSv,and the annual dose of internal irradiation was 0.162(0.132-0.180)mSv/a.Conclusion The internal exposure of NMWs in the eight hospitals in Guangdong Province meets the annual effective dose limits(≤20.000 mSv/a).However,it is necessary to pay attention to the internal radiation protection of NMWs and take reasonable protective measures to reduce the internal exposure risk of NMWs.