日射量的估算及其对牙釉质电子自旋共振剂量学的影响  

Estimation of solar radiation and its effects on tooth enamel electron spin resonance dosimetry

作　　者：焦玲[1] 张文艺[1] 丁艳秋[1] 张良安[1] 星正治[2] 

机构地区：[1]中国医学科学院中国协和医科大学放射医学研究所,天津300192 [2]广岛大学原爆放射线医科学研究所

出　　处：《中华放射医学与防护杂志》2009年第3期306-309,共4页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的探讨日射量的估算方法及太阳光辐射对牙釉质电子自旋共振（ESR）剂量学的影响。方法用机械方法获得11个牙釉质样品。用照度计测量太阳光的照度，通过比较日本气象厅在广岛市测得的瞬时日射量和相同时刻所测得的照度，计算出转换系数，然后估算出照射在牙釉质样品的累积日射量。用^60Coγ射线和太阳光分别照射牙釉质样品，使用ESR波谱仪测量不同辐射后牙釉质样品的ESR信号。结果照度与瞬时日射量的转换系数为（8.67±0.22）W·m^-2·klx^-1。照射在牙釉质样品上的累积日射量为（580±16）MJ/m^2。太阳光辐射也引起γ射线照射产生的剂量学信号，而且随累积日射量而线性增强，太阳光辐射还产生一个紧邻本底的信号，当累积日射量大于某一值时，该信号趋于饱和状态。结论用剂量学信号对所受辐射剂量进行评价，本研究中每MJ／m^2的太阳光辐射的影响相当于（7.7±1.4）mGy的γ射线辐射。紧邻本底的ESR信号可作为太阳光辐射的标志峰，有助于判断所收集的样品是否受到太阳光辐射，从而提高小剂量重建的准确度。Objective To investigate solar radiation and its effects on human tooth enamel electron spin resonance （ESR） dosimetry. Methods 11 tooth enamel samples were prepared by mechanical method. The intensity of solar illuminance was measured with a light meter, the measured illuminance was converted to insolation using a coefficient. Summation of solar radiation was evaluated. Enamel samples were exposed to ^60Co γ rays followed by sunlight on sunny days, and ESR spectra were scanned after different exposure. Results The conversion coefficient for measured illuminance to insolation was （8.67±0.22） W·m^-2·klx^-1. The integrated solar radiation to the samples was （580±16） MJ/m^2. Solar exposure also caused dosimetric signal. The perpendicular component of dosimetric signal increased linearly with the amount of solar radiation, another signal close to background tended to saturation. Conclusions The average effect of the solar radiation on the signal was estimated by dose equivalent γ ray irradiation as （7.7±1.4） mGy·（MJ/m^2）^-1. Signal near to background may be used to recognize the effect of solar radiation on the enamel, and estimate external dose accurately.

关 键 词：太阳光照度 日射量 牙釉质 电子自旋共振 剂量学 

分 类 号：R144[医药卫生—公共卫生与预防医学]