A model of radioiodine transfer to goat milk incorporating the influence of stable iodine
Crout, N.M.J.; Beresford, N.A.; Mayes, R.W.; MacEachern, P.J.; Barnett, C.L.; Lamb, C.S.; Howard, B.J.. 2000 A model of radioiodine transfer to goat milk incorporating the influence of stable iodine. Radiation and Environmental Biophysics, 39 (1). 59-65. 10.1007/PL00007678Full text not available from this repository.
Previously reported models for radioiodine in ruminants cannot account for the effect of variations in stable iodine intake including large countermeasure doses of stable iodine on the transfer of radioiodine to goat milk. A metabolically based model of radioiodine transfer in goats has been parameterised using new experimental data on the effect of countermeasure doses of stable iodine on radioiodine transfer to milk. To account for the effect of dietary stable iodine levels, the model represents the transfer of iodine from the extracellular fluid to milk with Michaelis-Menten kinetics. The model shows good agreement with the experimental data, and the estimated parameters compare favourably with values which can be estimated from the literature. The parameterised model accounts for 95% of the variation in the observed data for milk, faeces, urine and thyroid (n=199). The model has been used to predict the effects of variation in stable iodine intake and the extent of consequent chemical contamination of milk by stable iodine. The time taken for radio-iodine to reach peak concentrations in milk following a deposition event is predicted to vary significantly (ca. 2 days) over a range of expected stable iodine intakes. Doses of stable iodine sufficient to reduce the radioiodine transfer to milk will result in stable iodine concentrations in milk greatly in excess of internationally advised limits. Therefore, we recommend that stable iodine supplementation not be used as a countermeasure to reduce radioiodine transfer to milk. Indeed, model predictions suggest that reductions in stable iodine intake would be a more effective countermeasure. However, this is unlikely to be feasible since the short physical half-life of 131I may not allow adequate time to implement changes in feed manufacture. The model described in this paper is freely available in ModelMaker 3.0 format (http://www.notingham.ac.uk/environmental-modelling/).
|Programmes:||CEH Programmes pre-2009 publications > Other|
|CEH Sections:||_ Environmental Chemistry & Pollution|
|Additional Keywords:||radioecology, metabolically based model, radioiodine transfer, ruminant, stable iodine effect, goat milk|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||14 May 2012 10:17|
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