title: A new simplified allometric approach for predicting the biological half-life of radionuclides in reptiles.
abstract: 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 (T1/2b) 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 T1/2b 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 T1/2b data are lacking. However, the effect of mass on reptilian radionuclide T1/2b is minimal. If sufficient measured data are available for a given radionuclide then it is likely that these would give a reasonable estimate of T1/2b in any reptile species.
authors.affiliation: Centre for Ecology & Hydrology, Bailrigg, Lancaster LA1 4AP, UK; School of Environment & Life Sciences, University of Salford, Manchester M4 4WT, UK. Electronic address: nab@ceh.ac.uk.
authors.forename: N A
authors.initials: NA
authors.lastname: Beresford
authors.affiliation: School of Environment & Life Sciences, University of Salford, Manchester M4 4WT, UK.
authors.forename: M D
authors.initials: MD
authors.lastname: Wood
mesh_terms: D000818:Animals; D006207:Half-Life; D008954:Models, Biological; D011829:Radiation Dosage; D011868:Radioisotopes / Q000378:metabolism*; D012911:Snakes / Q000378:metabolism*; D014426:Turtles / Q000378:metabolism*; D035501:Uncertainty
chemical_list: D011868:Radioisotopes
keywords: Allometry; Biological half-life; Radionuclide; Reptile