Preliminary Study of Dose Rates to Rhinoceros Basal Cells from a Radioactive Source to Deter Poaching

The five populations of rhinoceros species have declined in the wild due to poaching and habitat degradation, with demand for rhinoceros horn driving the poaching industry. The poaching of rhinoceros horn has critically threatened the conservation status of over half of these animals in the world today. To combat this threat and safeguard the species, a method involving the insertion of a radiation source into the rhinoceros's horn has been proposed. This approach aims to deter poachers due to public fear of radiation and enable the detection of smuggled horns based on the source's radioactive properties. To determine the health risks to the rhinoceros, this study presents the dose rate response functions to the rhino's epithelial basal stem cells that form the horn. The assessed responses assumed a modeled source centered at 10 and 20 cm above the basal stem cells. To identify the most appropriate source, dose rates were produced from gamma sources ranging from 0.1 to 2 MeV. Using numerical calculations, conservative dose rate estimates were determined as a function of energy and normalized to source activity, providing a foundation for computational results using Monte Carlo N-Particle Code version 6.2. With the dose rate responses as a function of energy and activity, the risk of deterministic and stochastic effects in this most at-risk tissue were understood based on the skin dose limitations for preventing deterministic effects to the rhinoceros.