Study of EPR/ESR Dosimetry in Fingernails as a Method for Assessing Dose of Victims of Radiological Accidents/Incidents

Abstract

The threat of nuclear terrorism and the potential for the use of radiation as a weapon make having an efficient and accurate radiation dosimetry methodology paramount. This study gives a physical/mechanical explanation to the behavior of EPR signals in fingernail dosimetry by modeling fingernails as sponges. Since previous work was performed using stressed (untreated) samples, they do not represent the realistic behavior of unstressed (treated) fingernails. The developed treatment eliminates the combined effect of the mechanical EPR signals, MIS1 (former MIS), and MIS2 (former BKS). As nail samples are physically restored with treatments, are not stressed, and display a response closer to that of in vivo specimens. The RIS is proportional to the radiation dose and shows a curvilinear dose response in unstressed samples using the additive dose method that can be modeled with a saturating exponential model (Grun model) for predicting residual or accidental radiological dose.Water content and mechanical stress were identified as the major factors affecting radiation sensitivity and its shape in fingernail EPR measurements respectively. It is proposed that treated samples be used in fingernail EPR dosimetry because they show more stable signals than untreated ones and have lower interpersonal and intrapersonal variability. Practical conditions of sample collection, preparation, and measurements at an accident site can be met with techniques illustrated in this study.v

X-Band Rapid-Scan Electron Paramagnetic Resonance of Radiation-Induced Defects in Tooth Enamel

“…The irradiator dose rate was verified using a U.S. Navy thermo luminescence dosimeter (TLD) as described by Reyes (11). The U.S. Navy dosimetry system DT-702/PD is traceable to the NIST 137 Cs source and is in full compliance with the requirements of the American National Standard for dosimetry ANSI HPS N13.11-2009.…”

“…Detailed descriptions of DT-702/PD can be found in previously published reports (12–14). Reyes estimated that the bias between the Navy TLD dosimeters and the 137 Cs irradiator was 6% (11). …”