title: Parameter uncertainty analysis of a biokinetic model of caesium.
abstract: Parameter uncertainties for the biokinetic model of caesium (Cs) developed by Leggett et al. were inventoried and evaluated. The methods of parameter uncertainty analysis were used to assess the uncertainties of model predictions with the assumptions of model parameter uncertainties and distributions. Furthermore, the importance of individual model parameters was assessed by means of sensitivity analysis. The calculated uncertainties of model predictions were compared with human data of Cs measured in blood and in the whole body. It was found that propagating the derived uncertainties in model parameter values reproduced the range of bioassay data observed in human subjects at different times after intake. The maximum ranges, expressed as uncertainty factors (UFs) (defined as a square root of ratio between 97.5th and 2.5th percentiles) of blood clearance, whole-body retention and urinary excretion of Cs predicted at earlier time after intake were, respectively: 1.5, 1.0 and 2.5 at the first day; 1.8, 1.1 and 2.4 at Day 10 and 1.8, 2.0 and 1.8 at Day 100; for the late times (1000 d) after intake, the UFs were increased to 43, 24 and 31, respectively. The model parameters of transfer rates between kidneys and blood, muscle and blood and the rate of transfer from kidneys to urinary bladder content are most influential to the blood clearance and to the whole-body retention of Cs. For the urinary excretion, the parameters of transfer rates from urinary bladder content to urine and from kidneys to urinary bladder content impact mostly. The implication and effect on the estimated equivalent and effective doses of the larger uncertainty of 43 in whole-body retention in the later time, say, after Day 500 will be explored in a successive work in the framework of EURADOS.
authors.affiliation: HMGU-Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Neuherberg D-85764, Germany wli@helmholtz-muenchen.de.
authors.forename: W B
authors.initials: WB
authors.lastname: Li
authors.affiliation: KIT-Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Klein
authors.affiliation: IRSN-Internal Dose Assessment Lab., PRP-HOM/SDI/LEDI, BP-17, Fontenay-aux-Roses Cedex F-92262, France.
authors.forename: E
authors.initials: E
authors.lastname: Blanchardon
authors.affiliation: PHE-Department of Toxicology, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot OX11 0RQ, UK.
authors.forename: M
authors.initials: M
authors.lastname: Puncher
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Leggett
authors.affiliation: HMGU-Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Neuherberg D-85764, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Oeh
authors.affiliation: KIT-Safety Management, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Breustedt
authors.affiliation: BfS-Department of Radiation Protection and Health, Ingolstädter Landstr. 1, Oberschleißheim 85764, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Noßke
authors.affiliation: CIEMAT-Dosimetría Interna, Departamento de Medio Ambiente, Avda Complutense 40, Madrid 28040, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Lopez
mesh_terms: D002588:Cesium Radioisotopes / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D003198:Computer Simulation; D004781:Environmental Exposure; D006801:Humans; D008954:Models, Biological; D016273:Occupational Exposure; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000706:statistics & numerical data; D011835:Radiation Protection; D019275:Radiopharmaceuticals / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D015203:Reproducibility of Results; D014018:Tissue Distribution; D035501:Uncertainty
chemical_list: D002588:Cesium Radioisotopes; D019275:Radiopharmaceuticals