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

Abstract

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. Key words: Chewing lime tobacco; Tooth enamel; Electron spin resonance; Dosimetry; Background signals