EPR emergency dosimetry with plastic components of personal goods.

Radiation-induced electron paramagnetic resonance (EPR) signals were studied in samples of plastic materials of various origin: buttons, details of underwear, elements of mobile phones, etc. The following parameters were investigated: dose response curve in the range 0-25 Gy; stability of potential dosimetric signals at different temperatures of storage after exposure; and influence of solar radiation on the dosimetric properties of materials. Plastics from personal goods were found to be a potentially acceptable material for use as individual EPR dosimeters with sensitivity threshold below 5 Gy. Radiation-induced EPR signals in plastic demonstrated clear saturation for doses above 10 Gy. Fading of dosimetric signals was best described by the two-exponential decay function with fast and slow decay components. Values of slow decay constant were approximately 2 and 15 d, while the corresponding values for the fast decay component were approximately 2 and 15 h for temperatures of +25 degrees C and -18 degrees C, respectively. Strong influence of solar light radiation on EPR spectra was observed for unexposed and gamma-irradiated plastic samples, which may affect drastically the results of dose reconstruction.