Azariasl Samayeh, Yasuda Hiroshi
Department of Radiation Biophysics, Research Institute for Radiation Biology and Medicine (RIRBM), Hiroshima University, Hiroshima, Japan.
Phoenix Leader Education Program (Hiroshima Initiative) for Renaissance from Radiation Disaster, Hiroshima University, Hiroshima, Japan.
Front Public Health. 2025 Jan 15;13:1531253. doi: 10.3389/fpubh.2025.1531253. eCollection 2025.
Biodosimetry is crucial for assessing ionizing radiation exposure to guide medical responses. Electron spin resonance (ESR) spectroscopy using fingernails can be effectively used for both occupational and public dose assessments in radiological accidents because of their accessibility and ability to retain stable radiation-induced free radicals. However, despite two decades of research, challenges remain in achieving accurate fingernail dosimetry, mainly owing to the variation in ESR signals among individuals. The purpose of this study was to explore inter-individual differences in ESR signals in fingernails to improve the accuracy and reliability of extremity dosimetry. Fingernail samples were collected from 15 participants (age: 11-64 years), irradiated with X-rays (160 kV, 6.3 mA) at 0, 5, 10, and 20 Gy, and measured using ESR spectroscopy. The effects of individual factors, such as age, sex, health condition, and lifestyle, on radiation-induced ESR signals (RIS) were investigated. Younger participants exhibited stronger RIS intensities and a more linear dose-response relationship. The RIS intensity in female samples tended to be higher than that in male samples. Interestingly, the fingernals of middle-aged donors who regularly took vitamin supplements showed significantly higher ESR signal intensities than those of similar-age donors who did not take supplements. Notable reductions in RIS intensity during storage in a freezer were observed only in older donor samples irradiated at higher doses. These findings underscores the importance of considering age and other individual factors in the calibration for fingernail dosimetry.
生物剂量测定对于评估电离辐射暴露以指导医疗应对至关重要。由于指甲易于获取且能够保留稳定的辐射诱导自由基，利用指甲进行的电子自旋共振（ESR）光谱学可有效地用于放射事故中的职业和公众剂量评估。然而，尽管经过了二十年的研究，实现准确的指甲剂量测定仍存在挑战，主要原因是个体间ESR信号存在差异。本研究的目的是探索指甲中ESR信号的个体间差异，以提高四肢剂量测定的准确性和可靠性。从15名参与者（年龄：11 - 64岁）采集指甲样本，分别以0、5、10和20 Gy的剂量用X射线（160 kV，6.3 mA）进行照射，并使用ESR光谱学进行测量。研究了年龄、性别、健康状况和生活方式等个体因素对辐射诱导的ESR信号（RIS）的影响。较年轻的参与者表现出更强的RIS强度和更线性的剂量反应关系。女性样本中的RIS强度往往高于男性样本。有趣的是，定期服用维生素补充剂的中年捐赠者的指甲显示出的ESR信号强度明显高于未服用补充剂的同龄捐赠者。仅在高剂量照射的老年捐赠者样本中观察到在冷冻储存期间RIS强度有显著降低。这些发现强调了在指甲剂量测定校准中考虑年龄和其他个体因素的重要性。
