Uncertainties of internal dose assessment for animals and plants due to non-homogeneously distributed radionuclides

Methods for calculating dose conversion coefficients for terrestrial and aquatic biota

“…Many radionuclides concentrate in specific organs, e.g., thyroid ( 131 I, 129 I), bone ( 90 Sr, 226 Ra), liver ( 239 Pu) or kidney ( 238 U). First results about the effect of such an inhomogeneous distribution are given by Gómez-Ros et al (2008). If a radionuclide accumulates in a specific organ, the ratio of the average dose rates in the organ and the whole body can be approximated by the ratio of the masses of whole body and organ.…”

Application of computational models to estimate organ radiation dose in rainbow trout from uptake of molybdenum-99 with comparison to iodine-131

“…99m Tc is a gamma emitter so its emissions will therefore deposit energy more evenly within the body than beta emitters; beta particles generally have a shorter path and tend to deposit most of their energy at the end of their track (Cember and Johnson, 2009). The mass ratio approach is generally a reasonable approximation of organ dose, although more appropriate for beta emitters (or other low penetrating or low energy radiation) in agreement with G omez- Ros et al (2008) and as discussed by Ruedig et al (2015).…”

“…In the absence of organ-specific data, a conservative estimate of organ dose is given by the product of the whole body dose and the ratio of the mass of the whole body to the mass of the particular organ of interest (G omez-Ros et al, 2008). It should be noted that this approach is only valid for organs that are both the source and the target of radiation.…”

Challenging the current strategy of radiological protection of the environment: arguments for an ecosystem approach

“…Overall, large uncertainties still weaken the reach of a robust synthesis from such data base because of the subsistence of wide knowledge gaps for a number of common wildlife species on responses from chronic exposure to internal irradiation from bio-accumulated a and b emitting radionuclides, and at higher levels of biological organisation beyond individuals (populations, communities, ecosystems), (Gomez-Ros et al, 2008;Oughton et al 2008). All together, these shortcomings lead to the requirement for the assessment methodology to rely on various extrapolations, the robustness of which needing proof and justification.…”