SAVE THE PANGOLINS! COBALT-60 AS A RADIOACTIVE DETERRENT FOR PANGOLIN PRESERVATION

Abstract

Pangolins are the most trafficked mammal in the world; nearly 2.7 million African pangolins are illegally poached each year. Placement of Cobalt-60 on pangolins as a radioactive deterrent is intended to alarm existing radiation portal monitor networks at border crossings and eventually protect pangolin populations from illegal poaching. Dimethyl sulfoxide was proposed as a carrier to embed the radioactive Cobalt-60 tracer into a pangolin’s keratinous scales. The goal of the study was to estimate the radiation dose to the pangolin via first-principles calculations and computer modeling to ascertain the viability of the proposed deterrent. Calculation of dose to the pangolin’s body and potentially radiosensitive organs was required to prevent any potential radiation injury to the pangolin. Monte Carlo N-Particle (MCNP) simulation and first-principles calculations demonstrated that pangolin scales are thick enough to absorb the maximum energy beta particles emitted as Cobalt-60 decays and the resultant bremsstrahlung is negligible. Placement of 0.01 MBq of Cobalt-60 over an area of 200 cm2 produced an MCNP calculated whole-body photon dose of 11.6 ± 0.1 mGy y-1 (1.33 ± 0.01 µGy h-1) and a basal layer of the skin dose of 22.7 ± 0.1 mGy y-1 (2.59 ± 0.01 µGy h-1). Any agency intending to use the radioactive deterrent method for the pangolin must consider the radioactivity level that would optimize both detection and deterrence and meet the organization’s established, acceptable risk to the pangolin, the public, and the environment.