Dose Reconstruction with Electron Paramagnetic Resonance Spectroscopy of Deciduous Teeth

Wieser, A.; El-Faramawy, Nabil

doi:10.1093/oxfordjournals.rpd.a006045

Cited by 14 publications

(8 citation statements)

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“…Using this technique, the high measurement errors in a low dose could be from multiple irradiations of the same sample to determine low doses. While using spectra deconvolution computer software, the dose measurements errors were more than 20% at the low doses (100–500 mGy) in tooth enamel (Ivannikov et al 2002; Wieser et al 2002; Zhumadilov et al 2006). However, the dose spiking technique can amplify the RIS signal amplitude high enough to be seen and measured in the single irradiation dose.…”

Section: Resultsmentioning

confidence: 99%

“…Likewise, Ivannikov et al (2002) used an automatic computer procedure (i.e., spectra deconvolution procedure) for processing spectra from 100-500 mGy by extracting the RIS from the total EPR spectrum and determining the RIS intensity. This procedure deconvolutes the total EPR spectrum of tooth enamel to the RIS and BGS by applying non-linear squares fitting of a model spectrum to the experimental one (Ivannikov et al 2002;Wieser et al 2002;Zhumadilov et al 2005Zhumadilov et al , 2006. However, these studies did not determine the spectra deconvolution procedure's ability to differentiate the RIS and BGS in the tooth enamel EPR spectrum at the low dose range (10-100 mGy).…”

Section: Standard Techniques For Low Dose Measurementsmentioning

confidence: 99%

“…However, given their availability, there are more chances of providing deciduous teeth for dose reconstruction in the actual radiation accidents like Fukushima Daiichi Power Plants (Murahashi et al 2017). Moreover, it is paramount to determine the accident doses or over-exposures in children (6–12 years) because children are more susceptible than adults to ionizing radiation due to their higher radiation risk per dose (UNEP 2016; ICRP 2007; Wieser and El-Faramawy 2002). The characteristic of the EPR dosimetric signals from the deciduous teeth enamel was investigated, and it was found that their radiation sensitivities were the same as the permanent teeth (Murahashi et al 2017).…”

Section: Introductionmentioning

confidence: 99%

“…Despite its advantages, only a few studies have been done to reconstruct the low absorbed doses in deciduous teeth, which were able to measure low doses higher than 100 mGy (Gualtieri et al 2001; Murahashi et al 2017; Wieser and El-Faramawy 2002). However, it is vital to measure the low doses in the range of 10 to 100 mGy in enamel, which is of interest in radiation epidemiology due to plausible health effects but not observed until now (UNSCEAR 2012).…”

Section: Introductionmentioning

confidence: 99%

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The Dose Spiking Technique for Measuring Low Doses in Deciduous Teeth Enamel Using EPR Spectroscopy for Retrospective and Accident Dosimetry

Ghimire

Waller²

2022

Health Physics

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Dose estimation by electron paramagnetic resonance (EPR) has been accomplished using the standard EPR dosimetry technique (ISO protocol 13304-1 for EPR retrospective dosimetry). However, different studies showed that these techniques have high measurement errors in measuring the low doses (10–100 mGy) in enamel. This work proposes a new method to make a dosimetric signal visible and measurable at low doses. The sample was purified using both chemical and mechanical processes. The pure sample mass and position and the EPR acquisition parameters were optimized to enhance the spectrometer's sensitivity for the quantitative low dose measurements. At the same time to reduce errors from the sample and spectrum anisotropy, the total doses (low plus spike) and the spike dose (4 Gy) were measured by rotating 0 to 360 degrees (i.e., 40 degrees at a time) relative to constant magnetic field direction using a goniometer. Subsequently, the spectra were averaged after their g-factor normalization. However, at low doses (<30 mGy), the radiation induced signal (RIS) was obscured by the background signal (BGS). So, the dose spiking technique was used as an alternative method. Ten low-dose deciduous molar tooth enamel (10–100 mGy) samples were spiked to the higher doses by delivering 4 Gy and measured using the X-band continuous wave (CW) EPR (Bruker EMXmicro) spectrometer. The total dose EPR signal was distinctly visible, and the peak-to-peak (P2P) amplitude height was measured. Then, the total dose was subtracted with the spike, often called a reference sample, to determine the initial low doses. The measurement errors using this method were lower than the previous methods. These results demonstrated that this method could be promising for solving low dose measurement problems in EPR dosimetry with deciduous and permanent tooth enamel.

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Section: Resultsmentioning

confidence: 99%

Section: Standard Techniques For Low Dose Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Dose Spiking Technique for Measuring Low Doses in Deciduous Teeth Enamel Using EPR Spectroscopy for Retrospective and Accident Dosimetry

Ghimire

Waller²

2022

Health Physics

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“…One of the calibration curve method's major limitations is finding a sample with less background and artificial doses (Fattibene and Callens 2010). Deciduous teeth enamel sensitivity is the same as for permanent teeth (Wieser and El-Faramawy 2002); however, they contain less background interferences and artificial doses, which may decrease errors in the final dose measurement of an unknown sample. So different age group (10–12 y) samples were mixed and divided into 8 aliquots of the same mass (105 mg).…”

Section: Methodsmentioning

confidence: 99%

Electron Paramagnetic Resonance Measurements of Lifetime Doses in Teeth of Durham Region Residents, Ontario

Ghimire

Waller²

2022

Health Physics

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The Canadian Nuclear Safety Commission (CNSC) and Ontario Power Generation (OPG) determined the total dose contribution of nuclear power plants in Durham Region populations by analyzing environmental samples from the surrounding areas of both nuclear generating stations (Pickering and Darlington). However, the total doses from the various sources were unknown in Durham Region populations, Ontario. Electron paramagnetic resonance (EPR) dosimetry with tooth enamel has been successfully established as an effective tool for gamma dose assessment for chronic and acute exposures in individuals, groups, or populations to reconstruct the absorbed dose down to 30 mGy. This study collected the extracted teeth from people of different ages in Durham Region, Ontario, and analyzed them using the x-band continuous wave (CW) EPR spectrometer. The total dose rate from the natural and anthropogenic sources was 1.9721 mSv y−1. The anthropogenic dose rate from the various sources was 0.6341 mSv y−1, about 47.39% of the natural background dose (1.338 mSv y−1) in Durham Region, Ontario. The combined anthropogenic doses from these sources were lower than the local background dose in Durham Region and lower than the regulatory annual effective dose limit of 1 mSv y−1 in Canada. Based on these data, this study concluded that the anthropogenic dose contribution was lower than the regulatory limit to the local populations.

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The use of deciduous molars in EPR dose reconstruction

El-Faramawy¹,

Wieser²

2006

Radiat Environ Biophys

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In the present study naturally loose deciduous molars were investigated. The feasibility of separating enamel from small size molars was analysed. EPR spectrum parameters of whole molars and separated enamel only were evaluated before and after laboratory irradiation. The Electron paramagnetic resonance (EPR) signal amplitudes of CO (2) (-) and native signals were determined by spectrum deconvolution, as a function of radiation dose in the range 0.1-10 Gy. A detection threshold of absorbed dose from deciduous molars of 198 and 21 mGy is estimated for massive (that contained both enamel and dentine) and grainy samples (that contained enamel only), respectively. The elimination of the organic material from the massive deciduous samples reduced the mean bias dose for the native signal from 90+/-18 to 34+/-13 mGy. A decay of the background signal within 2 weeks after irradiation was found, while the dosimetric signal was stable before and after the irradiation process. The presented results suggest deciduous teeth to be suitable for retrospective dose assessment. To get reasonable dose estimates, however, any organic material must be eliminated, and the measurements should be performed 2 weeks after the chemical and mechanical preparation and the irradiation process are done.

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Dose Reconstruction with Electron Paramagnetic Resonance Spectroscopy of Deciduous Teeth

Cited by 14 publications

References 0 publications

The Dose Spiking Technique for Measuring Low Doses in Deciduous Teeth Enamel Using EPR Spectroscopy for Retrospective and Accident Dosimetry

The Dose Spiking Technique for Measuring Low Doses in Deciduous Teeth Enamel Using EPR Spectroscopy for Retrospective and Accident Dosimetry

Electron Paramagnetic Resonance Measurements of Lifetime Doses in Teeth of Durham Region Residents, Ontario

The use of deciduous molars in EPR dose reconstruction

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