职业性外照射个人剂量监测中本底值选择的探讨

目的 探讨个人剂量监测中医院不同科室本底值的差异情况。方法 按不同职业类别对医院科室进行分组,并布放跟随本底剂量计,将测得的本底值分别与机关办公室对照本底值进行比较分析。结果 该医院本底剂量水平在0.22~0.33 mSv范围,机关办公室的3个布点办公书柜、办公桌抽屉、办公桌面本底值分别是（0.28±0.02） mSv、（0.28±0.01） mSv、（0.31±0.01） mSv;与机关办公室本底值相比,普放1层、口腔科、放疗中心1层、导管室1层均大于机关办公室（P<0.05）,CT区、PET-CT控制室、神经外科、实验室均小于机关办公室（P<0.05）,心内科与机关办公室没有统计学差异（P>0.05）。结论 不能使用单一本底值作为一种个职业分类或一个单位的本底值,应对每个科室布放跟随本底剂量计来降低本底值结果的误差。

Discussion on background radiation value in personal monitoring of occupational external exposure

Objective To investigate the differences in the background radiation values of different departments in medical institutions in personal dose monitoring. Methods According to different occupational categories, place the following background dosimeters for each department and the administration office ina top three military hospital, compare and analysis the differences of the measured background radiation values between them. Results The background radiation values of the monitored unit were in the range of 0.22~0.33 mSv. The measured values of dosimeters which were placed in the bookcase, desk drawer and on the desk surface of the administration office were 0.28±0.02 mSv, 0.28±0.01 mSv and 0.31±0.01 mSv respectively.Compared with the administration office, the background radiation values of radiology department, dental department, radiotherapy center, and catheter room were larger respectively,in which exists statistical significance (P<0.05), while the background radiation values of CT area, PET-CT control room, neurosurgery, laboratory were smaller respectively,in which also exists statistical significance (P<0.05),but there was no statistical difference between the values of the department of cardiology and the administration office (P>0.05). Conclusion Single background radiation value cannot be used to represent the background radiation value of a occupational categoryand a unit. Placing the following background dosimeters for each department can reduce the error of the background radiation value and enhance the ability of quality control.