Scientists understand how radiation moves through humans and can use extensive modeling to understand how to better protect them from radiation. Animals however, are a different story. Emily Caffrey modeled marine life for her master’s thesis in radiation health physics and hopes her research brings scientists one step closer to understanding radiation in sea life. 
“Creating the model for sea life is the same process as it is for humans,” Caffrey said. “We use a combination of CT and MRI scans to create a three dimensional model of the organism and then run computer simulations on the models and do dose estimations.”
 
The voxel phantoms are created from CT and MRI images that have been segmented to identify different parts of the body and their density, then combined into volumetric pixels to create a 3D rendering of the subject. Caffrey created the voxel phantom of the Dungeness crab (Metacarcinus magister), and the Sand Dab, (Limanda limanda). 
 
Once the voxel phantoms have been created researchers can run dose simulations and predict how different levels of radiation would affect the animals. There are still many unknowns in this area of research. The background levels, the amount of radiation marine life are exposed to naturally, is not fully understood. 
 
“We don’t really know how to calculate dose for marine organisms,” Caffrey said, “but making my data available to the international community could help calculate new dose conversion factors and figure out where the limits are for remediation of a contaminated marine site.”
 
Dose limits for wildlife has been a theme of several radioecology projects at NERHP. Other studies are examining the uptake for snails, and how radio-isotopes travel through the ocean food web. 
 
Caffrey’s models have been added to the knowledge base for the international community so researchers can use them for dose simulations.