Emergency EPR dosimetry technique using vacuum-stored dry nails

Area of Science:

• Biophysics
• Radiation Dosimetry

Background:

• Electron Paramagnetic Resonance (EPR) spectroscopy is a sensitive technique for detecting unpaired electrons.
• Nails contain keratin, a material that can trap radicals upon exposure to ionizing radiation.
• Previous studies explored EPR dosimetry using biological samples, but nail stability under various storage conditions requires further investigation.

Purpose of the Study:

• To evaluate the stability of radiation-induced EPR signals in human fingernails and toenails under different storage conditions.
• To develop and validate a novel dosimetry protocol for emergency radiation dose assessment using human nails.

Main Methods:

• Human finger and toenail samples were subjected to X-band EPR analysis.
• Samples were stored under various conditions, including vacuum and room temperature, post-irradiation.
• The stability of the radiation-induced EPR signal at g=2.005 was assessed.

Main Results:

• The primary radiation-induced EPR signal at g=2.005 exhibited significant stability when samples were stored in a vacuum at room temperature after irradiation.
• The proposed dosimetry protocol successfully recovered radiation doses in the 0-10 Gy range.
• Estimated uncertainties were approximately 0.3-0.4 Gy for doses below 2 Gy and 0.6-0.7 Gy for doses between 5-10 Gy.

Conclusions:

• Human nails, when stored appropriately post-irradiation, can be utilized as effective emergency dosimeters.
• The developed protocol offers a reliable method for retrospective radiation dose assessment in emergency situations.
• Vacuum storage at room temperature is crucial for maintaining signal integrity in nail dosimetry.