Retrospective dose assessment in a radiation mass casualty by EPR and OSL in mobile phones

In the retrospective dose assessment of individuals potentially exposed to ionizing radiation after an accident, dosimetry with inert materials can complement or be used as an alternative to biodosimetry assays. Dosimetry based on physical methods such as Electron Paramagnetic Resonance (EPR), Thermoluminescence (TL) or Optically Stimulated Luminescence (OSL) provides measurements of absorbed dose in a variety of materials through the measurement of the radiation damage therein induced. Materials contained in personal objects can therefore be collected and used almost as physical personal dosimeters. Portable electronic devices (PED), i.e. mobile phones, MP3 players, watches, cameras, USB memory sticks, are very appropriate personal items because nowadays they are owned and carried by all groups of a large part of the population. Here, we propose a combined system of dose measurements based on the use of EPR and OSL measurement of different components from the same electronic portable device (specifically mobile phones). Mineral glass used in window displays and alumina rich substrates contained in electronic components (e.g. resistors, etc.) used in the electronic boards acquire paramagnetic or luminescent properties under irradiation. The induced radiation damage can then be detectable by EPR and OSL. This work is carried out in the framework of the EU funded project Multibiodose with the objective to develop and validate methods for dose assessment specifically in a mass-casualties scenario. The first part of this work was dedicated to: a) classify the types of glass and of electronic components according to their characteristics, b) estimate the related radiation sensitivity and the stability with time of the EPR and OSL signals. Seventy-five mobile phones of different brands and models were analyzed at three partner laboratory.