Dose Rate Assessment Exercises with Stylized Phantom of Neon Flying Squid from Northwest Pacific

Radiation protection for non-human marine organisms still faces many challenges. To establish a more realistic radiation dosimetry model of cephalopods, this study developed a stylized phantom of neon flying squid (Ommastrephes bartramii) containing ten organs and tissues based on magnetic resonance imaging (MRI) technology. The internal and external dose conversion coefficients for eight radionuclides (Cs-134, Cs-137, I-131, Ag-110m, Co-60, Mn-54, Zn-65, Zr-95) of each organ/tissue were determined with Monte Carlo simulation using the Geant4 toolkit. Furthermore, with the reported coastal seawater radioactivity levels at the coastal area of Fukushima Daiichi Nuclear Power Plant after the accident in 2011 as the source term, the radiological dose rate for O. bartramii was evaluated with the stylized phantom developed in this study and with the conventional whole-organism ellipsoidal model in the ERICA Assessment Tool. Both results showed that the dose rate for O. bartramii derived from the FDNPP accident releases exceeded the generic no-effects screening benchmark level (10 mu Gy h(-1)).

Automated summary

This study developed a simulated model of squid using MRI technology to study radiation dosimetry. The results showed that the radiation dose from the Fukushima accident exceeded safety standards.