Radioactivity and radionuclides in deciduous teeth formed before the Fukushima-Daiichi Nuclear Power Plant accident

Abstract

The Fukushima-Daiichi Nuclear Power Plant (FNPP) accident in March of 2011 released substantial amounts of radionuclides into the environment. We collected 4,957 deciduous teeth formed in children before the Fukushima accident to obtain precise control data for teeth formed after the accident. Radioactivity was measured using imaging plates (IP) and epidemiologically assessed using multivariate regression analysis. Additionally, we measured 90Sr, 137Cs, and natural radionuclides which might be present in teeth. Epidemiological studies of IP showed that the amount of radioactivity in teeth from Fukushima prefecture was similar to that from reference prefectures. We found that artificial radionuclides of 90Sr and 137Cs, which were believed to have originated from past nuclear disasters, and natural radionuclides including 40 K and daughter nuclides in the 238U and 232Th series contributed to the generation of radioactivity in teeth. We also found no evidence to suggest that radionuclides originating from the FNPP accident significantly contaminated pre-existing teeth. This is the first large-scale investigation of radioactivity and radionuclides in teeth. The present findings will be indispensable for future studies of teeth formed after the FNPP accident, which will fall out over the next several years and might be more contaminated with radionuclides.

Spectroscopic and dosimetric comparison of tooth enamel separation methods for EPR retrospective dosimetry

“… To get reproducible result [ [25] , [26] , [27] , [28] ]. To avoid over estimation of dose due to presence of ingested radionuclides Cs 137 and Sr 90 in dentine [ 3 , 20 , 29 ]. …”

“…To avoid over estimation of dose due to presence of ingested radionuclides Cs 137 and Sr 90 in dentine [ 3 , 20 , 29 ].…”

Direct Quantification of Attogram Levels of Strontium-90 in Microscale Biosamples Using Isotope Dilution-Thermal Ionization Mass Spectrometry Assisted by Quadrupole Energy Filtering

“…In particular, the measurement of microscale samples, such as tears, saliva, and teeth, are required for assessing the degree of internal radiation exposure and to understand the dynamics of radiomaterials. 1,2 In radiometric analysis, the isolation of 90 Sr from other radionuclides and the generation of the more easily detectable daughter nuclide 90 Y, which has a higher β-particle energy than 90 Sr, is time intensive. On the other hand, mass spectrometry (MS) has recently emerged as a powerful rapid measurement tool for quantifying low concentrations of 90 Sr.…”

“…Thus, there is an increasingly high demand for 90 Sr-analysis methods. In particular, the measurement of microscale samples, such as tears, saliva, and teeth, are required for assessing the degree of internal radiation exposure and to understand the dynamics of radiomaterials. , …”

“…The accumulation of low levels of radionuclides on a microscale or specific local parts of biological , or precious environmental samples is of interest to many researchers. Such knowledge will promote the understanding of the dynamics in various fields, enabling the assessment of internal exposure in the body and the understanding of environmental dynamics, nuclear forensic sciences, geochemistry, health foods, wildlife, and marine environment .…”