A close correlation between electron spin resonance (ESR) dosimetry from tooth enamel and cytogenetic dosimetry from lymphocytes of Hiroshima atomic-bomb survivors

Abstract

Purpose: To estimate gamma -ray doses received by Hiroshima atomic bomb survivors using electron spin resonance (ESR) of tooth enamel and to compare the results with cytogenetic data. Materials and methods: Tooth enamel ESR was performed for 100 teeth donated from 69 Hiroshima survivors, and conventional cytogenetic examinations were conducted for 61 of the tooth donors. To evaluate possible contamination from dental X-ray exposure, which primarily affects the tooth's buccal surface, each tooth was divided into buccal and lingual parts for subsequent independent enamel isolation and ESR measurement. Results: Almost 20 teeth showed considerably larger buccal doses than lingual doses, but most of these discrepant teeth were incisors and canines. The results are probably attributable to solar light exposure. In contrast, the buccal and lingual doses found in molars were similar. Conventional translocation data of lymphocytes and ESR-estimated doses of 40 donors of molars showed the dose-response for translocations to be almost the same as that expected from in vitro gamma -ray irradiation experiments. Conclusions: Both tooth enamel ESR and lymphocyte cytogenetics are useful measures for individual biodosimetry of acute radiation exposure, even half a century after the exposure occurred.