Dose estimation based on OSL signal from banknotes in accident dosimetry

Our work is focused on the optically stimulated luminescence (OSL) of paper currency of Polish zloty, especially 10 PLN and 20 PLN banknotes in regard to the dose reconstruction in an emergency situation involving radiation. 'New' Polish banknotes with enhanced anti-counterfeiting systems were investigated in comparison with 'old' banknotes which are still in circulation, as well as with 1 US dollar and 5 EURO banknotes. Similar dosimetric properties for 10 PLN and 20 PLN banknotes of 'old' and 'new' types were observed: relatively good repeatability of OSL signal, linear dose response in the dose range between 0.2 and 10 Gy, and fading reaching 65% of OSL signal after 5 h and remaining almost stable at the level of 45% after 48 h. Despite a high intrinsic initial signal of the 'new' type of Polish banknotes of 10 PLN and 20 PLN it is still possible to reconstruct the doses higher than 0.4 Gy two days after an incident with an accuracy better than 25%. In light of these results banknotes can be considered as potential triage dosimeters for retrospective dosimetry.