Electron spin resonance (ESR) method
The electron spin resonance (ESR) method–by which the radicals (unpaired electrons) in tooth enamel can be detected–has been used by many research institutions as another indicator of previous radiation exposure.
In 1995, an ESR detector was installed in the Cytogenetics Laboratory and has been used to examine about 100 of the more than 300 tooth samples donated by A-bomb survivors. A close relationship between ESR measurements and the chromosome aberration data for tooth donors has been found, which shows the ESR method is a powerful method for estimating individual radiation doses. The findings obtained by the ESR method also corroborate A-bomb survivors’ chromosome data.