Recent Issues in X-Band ESR Tooth Enamel Dosimetry

Radiation exposure is a primary concern in emergency response scenarios and long-term health assessments. Accurate quantification of radiation doses is critical for informed decision-making and patient care. This paper reviews the dose reconstruction technique using both X- and Q-bands, with tooth enamel as a reliable dosimeter. Tooth enamel, due to its exceptional resistance to alteration over time, offers a unique opportunity for assessing both acute and chronic radiation exposures. This review delves into the principles underlying enamel dosimetry, the mechanism of radiation interactions, and dose retention in tooth enamel. We explore state-of-the-art analytical methods, such as electron paramagnetic resonance (EPR) spectroscopy, that accurately estimate low and high doses in acute and chronic exposure. Furthermore, we discuss the applicability of tooth enamel dosimetry in various scenarios, ranging from historical radiological incidents to recent nuclear events or radiological incidents. The ability to reconstruct radiation doses from dental enamel provides a valuable tool for epidemiological studies, validating the assessment of health risks associated with chronic exposures and aiding in the early detection and management of acute radiation incidents. This paper underscores the significance of tooth enamel as an essential medium for radiation dose reconstruction and its broader implications for enhancing radiation protection, emergency response, and public health preparedness. Incorporating enamel EPR dosimetry into standard protocols has the potential to transform the field of radiation assessment, ensuring more accurate and timely evaluations of radiation exposure and its associated risks.

Section: Introductionmentioning

confidence: 99%

Electron Paramagnetic Resonance (EPR) Biodosimetry with Human Teeth: A Crucial Technique for Acute and Chronic Exposure Assessment

Ghimire,

Waller

2024

“…However, due to the high radiation sensitivity of tooth enamel and its extensive dose-response linearity from low to high doses, human teeth have been used extensively to assess the chronic exposures in nuclear workers and atomic bomb survivors (Zhumadilov et al 2006; Romanov et al 2002; Tatsumi-Miyajima and Okajima 1991; Nakamura et al 1998). Therefore, experimental determination of the absorbed dose in tooth enamel using EPR dosimetry is an essential tool to reconstruct doses in individuals, groups, or populations in case of radiation accidents or chronic exposures (Desrosiers and Schauer 2001; Zhumadilov et al 2005; Toyoda 2019).…”

Section: Introductionmentioning

confidence: 99%

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

Ghimire

Waller²

2022

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.

“…Additionally, human teeth are the only human tissue that can record a low dose with a very high dose stability rate. That is why the dental enamel has been used to reconstruct doses for a long time for retrospective radiation dosimetry and radio-epidemiology (Fattibene and Callens 2010; IAEA 2002; ICRU 2002; Jacob et al 2002; Toyoda 2019). The ionizing radiation generates high stable paramagnetic centers in dental enamel called carbon dioxide radical anions ( • CO 2 − ) (IAEA 2002; Rudko et al 2010; Lund et al 2011).…”

Section: Introductionmentioning

confidence: 99%

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

Ghimire

Waller²

2022

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.