Impact of different mechanical pre-treatment to the EPR signals of human fingernails towards studying dose response and fading subjected to UV exposure or beta irradiation

• Beta and UV induced EPR signals were analyzed.
• Specific impacts of mechanically induced EPR signals were studied.
• Application on forensic biodosimetry requires further studies.

In this study, fingernails were investigated by means of Electron Paramagnetic Resonance (EPR) technique, further exploiting its potential use in the field of retrospective dosimetry. The behavior of the radiation induced signal was investigated under beta irradiation and UV light exposure. Nevertheless, before these aforementioned experiments, the optimum handling procedure was established by studying the mechanical impact of various pre-treatments to the mechanically induced signal. The dose response was studied in the range between 1 and 100 Gy of beta irradiation for both accidental as well as high dose dosimetry purposes. The signal growth was observed to yield a saturation exponential behavior, while the signal was found to be appropriate for use towards retrospective dosimetry studies for assessing doses of the order of 1–2 Gy, provided that the samples are collected just after irradiation. One week after irradiation, the beta-radiation induced dose response indicated linear behavior. In order to estimate a dose from RIS2, first you have to subtract the BKS contribution from the EPR signal and also the MIS. After prolonged UV exposure of roughly 7 h, the UV-induced dose response reaches saturation, while the fading of thıs specific signal was also studied.