1. Determination of the Average Native Background and the Light-Induced EPR Signals and their Variation in the Teeth Enamel Based on Large-Scale Survey of the Population.
- Author
-
Ivannikov AI, Khailov AM, Orlenko SP, Skvortsov VG, Stepanenko VF, Zhumadilov KS, Williams BB, Flood AB, and Swartz HM
- Subjects
- Biological Assay methods, Biological Assay statistics & numerical data, Electron Spin Resonance Spectroscopy statistics & numerical data, Female, Humans, Male, Radiation Dosage, Radiation Monitoring methods, Radiation Monitoring statistics & numerical data, Reference Values, Reproducibility of Results, Russia, Sensitivity and Specificity, Tooth chemistry, Background Radiation, Dental Enamel chemistry, Dental Enamel radiation effects, Electron Spin Resonance Spectroscopy methods, Radiation Exposure statistics & numerical data, Solar Energy, Tooth radiation effects
- Abstract
The aim of the study is to determine the average intensity and variation of the native background signal amplitude (NSA) and of the solar light-induced signal amplitude (LSA) in electron paramagnetic resonance (EPR) spectra of tooth enamel for different kinds of teeth and different groups of people. These values are necessary for determination of the intensity of the radiation-induced signal amplitude (RSA) by subtraction of the expected NSA and LSA from the total signal amplitude measured in L-band for in vivo EPR dosimetry. Variation of these signals should be taken into account when estimating the uncertainty of the estimated RSA. A new analysis of several hundred EPR spectra that were measured earlier at X-band in a large-scale examination of the population of the Central Russia was performed. Based on this analysis, the average values and the variation (standard deviation, SD) of the amplitude of the NSA for the teeth from different positions, as well as LSA in outer enamel of the front teeth for different population groups, were determined. To convert data acquired at X-band to values corresponding to the conditions of measurement at L-band, the experimental dependencies of the intensities of the RSA, LSA and NSA on the m.w. power, measured at both X and L-band, were analysed. For the two central upper incisors, which are mainly used in in vivo dosimetry, the mean LSA annual rate induced only in the outer side enamel and its variation were obtained as 10 ± 2 (SD = 8) mGy y
-1 , the same for X- and L-bands (results are presented as the mean ± error of mean). Mean NSA in enamel and its variation for the upper incisors was calculated at 2.0 ± 0.2 (SD = 0.5) Gy, relative to the calibrated RSA dose-response to gamma radiation measured under non-power saturation conditions at X-band. Assuming the same value for L-band under non-power saturating conditions, then for in vivo measurements at L-band at 25 mW (power saturation conditions), a mean NSA and its variation correspond to 4.0 ± 0.4 (SD = 1.0) Gy., (© Crown copyright 2016.)- Published
- 2016
- Full Text
- View/download PDF