嚼烟习俗地区的牙釉质电子自旋共振剂量学的研究

目的 研究嚼烟习俗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20个孟买地区的舌侧牙釉质样品与10个混合均匀的日本人舌侧牙釉质样品。用⁶⁰Co γ射线分别照射部分牙釉质样品,使用ESR波谱仪测量辐射前和不同辐射剂量后牙釉质样品的ESR信号。结果 9个孟买牙釉质样品,其ESR的本底信号强度明显高于日本人的平均水平,为日本人水平的1.5~3.3倍。ESR本底信号强度较高的样品,γ射线照射后,剂量学信号的辐射响应略低,说明高本底可能降低了辐射剂量的灵敏度。6个样品辐射响应的平均值为(0.42±0.03)mGy,与日本牙釉质混合样品很相近。结论 嚼烟地区的部分牙釉质的ESR本底水平明显高于一般平均水平,可能是嚼烟中大量的烟碱与牙釉质相互作用的结果。进一步研究特殊生活习俗对牙釉质ESR剂量学的影响,有助于提高不同地区剂量重建的精度,为正确地评价辐射事故剂量提供科学依据。

Tooth enamel electron spin resonance dosimetry of people living in the area with lime tobacco custom

Objective To study the effect of the custom of long term chewing lime tobacco on human tooth enamel electron spin resonance (ESR) dosimetry. Methods A total of 20 enamel samples from lingual parts of adults teeth collected in Bombay, India were obtained by mechanical method. Some enamel samples from Japanese adults were extracted and 10 mixed samples were prepared. Enamel samples were exposed to different doses of 60Co γ-rays several times, and ESR spectra were measured after exposure. Results ESR background signals of 9 Bombay samples were found 1.5-3.3 times higher than those of Japanese mixed samples. The γ-ray dose responses of dosimetric signal with higher background level were a little lower, and the average sensitivity was (0.42 ± 0.03 )mGy, which was close to that of Japanese mixed samples. Conclusions The average level of background signals of Bombay samples was much higher than that of other non-chewing tobacco area, which was possibly caused by tobacco lime, the main component in chewing tobacco productions, and it would help to explore its special influences on ESR, and improve dose reconstruction in accuracy.