New fortuitous materials for luminescence dosimetry following radiological emergencies

The effective management of radiological emergencies where members of the public not carrying conventional dosimeter have been exposed to doses of ionising radiation requires individual dose estimates to support medical triage. Biological and physical methods have been developed to address this issue. New materials and techniques have been sought to reinforce preparedness for such emergencies. Alternative materials, such as clothing, shoes, paper, plastic items, nail polish or banknotes were investigated using thermoluminescence (TL) and optically stimulated luminescence (OSL). Most of the materials and fabric tested exhibited either no detectable response to dose using luminescence technique, or a weak response yielding detection limits above 2 Gy, with the exceptions of a blue polyester fabric responding to infra-red stimulated luminescence (IRSL) and some types of polymer-based fabric that were found to have luminescence favourable characteristics for short - term dosimetry and particularly those containing mineral fillers. The most promising were fabrics containing calcium carbonate fillers, where the TL response to β radiations was measured with a detection limit as low as 4 mGy, and a relatively low native signal in the region of interest (≤ 200 °C). The fading was found to be slower for samples stored at -15 °C compared with samples stored at ambient temperature. A blind test was carried out and confirmed the potential of bags containing calcium carbonate fillers to provide reliable dose estimate for radiological triage. Furthermore, the TL signal of calcium carbonate fillers contained in the fabric of bags offers several advantages for accident dosimetry compared with other methods, such as a rapid dose assessment, the low cost value of the material and availability, and the possibility to map radiological doses is the fabric covers sufficient surface.