低剂量电离辐射对医疗职业人群甲状腺结节患病的影响

Effect of exposure to low-dose ionizing radiation on the prevalence of thyroid nodules in a medical occupational population

目的:分析长期接触低剂量电离辐射对医疗职业人群甲状腺结节患病的影响及其影响因素,为该类人群的职业卫生防护提供依据。方法:以南京某三甲医院从事放射诊疗工作的人群为暴露组,以某企业未接触辐射的行政人员为对照组,通过问卷调查研究获取基本信息,通过疾控部门获取目标人群电离辐射的职业暴露剂量,采用彩色多普勒超声诊断仪检查甲状腺结节,运用Logistic回归模型分析相关影响因素。结果:两组人群在年龄、性别、工龄等方面具有较好的均衡性;暴露组人群辐射接触的剂量均低于国家限定值的1/10,属于低剂量暴露;暴露组甲状腺结节的异常率明显高于对照组,且随着人均年有效累计剂量和接害年限的增加出现显著增高趋势(P<0.05)。多因素Logistic回归分析也证实,年均有效累计剂量和接害年限均为甲状腺结节异常的独立危险因素,尤以年均累计有效剂量最为显著(OR=16.913,95%CI为2.212~129.336)。结论:长期接触低剂量电离辐射可引起医疗职业人群的甲状腺损伤,应当予以关注。

Objective The prevalence and its influencing factors were analyzed in a medical occupational population long-term exposure to low-dose of ionizing radiation in order to provide evidences for occupational health protection of this kind of population. Methods The population who engaged radiodiagnosis and radiotherapy in a tertiary-A hospital was set up as occupational exposure, and the administrative staffs in a company were considered as control. We figured out the basic information and general condition of the groups by face-to-face questionnaire survey, calculated the annual comulative radiation dose through local center for disease control and prevention, and obtained the prevalence of thyroid nodules by the thyroid ultrasound. Besides, we used the logistic regression model to analyze the risk factors related to thyroid nodule. Results Age, sex and seniority were proportionality between exposure and control groups. The dosages of occupational population exposure to ionizing radiation were about 1/10 of national permit value, belonging to low-dose exposure. However, the abnormal rate of the thyroid nodules in exposure group was significantly higher than that in control group, and the abnormal rate increased in trend with the annual comulative radiation dose and the exposure length （Ptrend〈0.05）. In addition, the multiple logistic regression showed that the annual comulative radiation dose and the exposure length were the independent risk factors for the abnormal rate of thyroid nodules, especially the annual comulative radiation dose （OR=16.913, 95%CI： 2.212-129.336）. Conclusion Long-term exposure to low-dose ionizing radiatiom could induce the thyroid damage of medical occupational population, which should be broader concerned.