A new simplified allometric approach for predicting the biological half-life of radionuclides in reptiles

摘要

A major source of uncertainty in the estimation of radiation dose to wildlife is the prediction of internal radionuclide activity concentrations. Allometric (mass-dependent) relationships describing biological half-life (T_(1/2b)) of radionuclides in organisms can be used to predict organism activity concentrations. The establishment of allometric expressions requires experimental data which are often lacking. An approach to predict the T_(1/2b) in homeothermic vertebrates has recently been proposed. In this paper we have adapted this to be applicable to reptiles. For Cs, Ra and Sr, over a mass range of 0.02-1.5 kg, resultant predictions were generally within a factor of 6 of reported values demonstrating that the approach can be used when measured T_(1/2b) data are lacking. However, the effect of mass on reptilian radionuclide T_(1/2b) is minimal. If sufficient measured data are available for a given radionuclide then it is likely that these would give a reasonable estimate of T_(1/2b) in any reptile species.