Towards low dose retrospective dosimetry on shelled species

Abstract

This work investigates calcified tissues of shelled species for retrospective dosimetry using electron paramagnetic resonance (EPR) spectroscopy. To determine applicable samples for low dose studies, shells of crustacean and mollusc species were irradiated to 10 Gy using a 137Cs source. Reference dosimetry was performed with alanine powder using a specifically developed calibration curve. Characteristic Mn2+ signals were present in the EPR spectra of all studied species. Radiation induced peaks were not detected in shells of any species except terrestrial snails. A dose-response curve for terrestrial snails was developed by irradiating shells to 2, 10, and 20 Gy. However, Mn2+ signals caused limitations in resolving radiation induced peaks below 2 Gy. Environmental factors were assessed, and it was found that shell structure and habitat characteristics contribute to Mn2+ signals in EPR spectra. Since high-intensity Mn2+ signals obscured radiation-induced peaks, shells of the studied aquatic species were deemed unsuitable for low dose retrospective dosimetry.