Investigation of the applicability of the ESR nail dosimetry for assessment of accidental exposure in medical facilities

Highlights: • A new setup modification for the fingernail ESR dosimetry was introduced. • Unique responses of fingernail ESR signals were found among three donors. • Fingernail ESR signals of each donor showed a good linearity of dose response up to 70 Gy. -- Abstract: The study of human fingernails as a possible dosimeter has continued to be of interest in the field of accident dosimetry because of its potential advantages. The present study aims to investigate the suitability of fingernails for the assessment of accidental exposure in medical facilities that use radiation for diagnosis or radiation therapy through the electron spin resonance (ESR) dosimetry technique. Relevant drying conditions, sample characteristics, and setup modifications were tested and compared among the samples of three different individuals. Results indicated that 1 h of sample drying inside a heat dryer sterilizer at 100 °C temperature showed good thermal stability of the ESR signals up to 30 days of postmeasurement. Another finding of this study was the effective approach in the signal stability for samples kept under vacuum storage condition with limited exposure to ambient light. While the samples from three different individuals showed unique dose–response curves after the X-ray irradiation, those were quite linear in the therapeutic dose range (up to 70 Gy). These results indicate that fingernails could be useful for the detection of unexpected significant exposure of patients and medical staff handling radiation or radiopharmaceuticals. Further investigations are desirable for standardization of the fingernail dosimetry in medical applications.