山羊牙釉质电子自旋共振的剂量学特性

Properties of goat tooth enamel electron spin resonance dosimetry

目的探讨山羊牙釉质电子自旋共振（ESR）的剂量学的特性。方法采用机械和化学处理相结合的方法，制备5组不同年龄的山羊牙釉质样品。用^137Csγ射线照射山羊牙釉质样品，使用ESR波谱仪测量辐射前和不同辐射剂量后不同牙釉质样品的ESR信号。结果^137Csγ射线照射前，山羊牙釉质所固有的ESR本底信号平均值为21.5，明显低于人的平均本底强度水平39.5；与人牙釉质相同，山羊牙釉质照射后产生的剂量学信号的强度与照射剂量线性相关，5组100mg山羊牙釉质样品，其剂量学峰的辐射灵敏度的平均值为（34.3±1.9）／Gy，与人牙釉质样品的辐射响应平均值36.3／Gy非常接近。结论人类牙釉质样品缺乏时，可以用相同辐射环境中的山羊牙釉质作为替代品进行剂量重建，为正确地评价辐射事故剂量提供科学依据。

Objective To study the properties of goat tooth enamel electron spin resonance （ESR） dosimetry. Methods Tooth enamel samples of goats were achieved by combined mechanical and chemical treatment at the ages of 1, 2, 3, 5, and 6 years, respectively and 9 enamel samples of adult molar were obtained. These enamel samples were exposed to 137^Csy-rays at the cumulative doses of 0, 0.5, 1.0, 2.0, and 5.0 Gy, respectively. ESR spectra was measured before and after exposure. Results The background signal of goat tooth samples was 21.5, significantly lower than that of the adult molar samples （39.5）. The dosimetric signal intensity of the goat enamel increased with the radiation dose in a linear manner just as that of the human molars. The average radiation sensitivity of the goat tooth samples was （34.3± 1.9）/Gy, close to that of the human tooth samples. Conclusions Goat teeth can be used for retrospective radiation dose reconstruction when human teeth are unavailable, in order to provide scientific data for dose reconstruction accurately.