Updating the icrp human respiratory tract model
The model treats monodisperse or polydisperse aerosol size distributions.The human respiratory tract (RT) model of the International Commission on Radiological protection (ICRP Publication 66) is utilized for the respiratory tract deposition calculations.It could be something as simple as a run away script or learning how to better use E-utilities, for more efficient work such that your work does not impact the ability of other researchers to also use our site.To restore access and understand how to better interact with our site to avoid this in the future, please have your system administrator contact [email protected]
The resulting distributions for dose per unit intake were lognormal with geometric standard deviations of 2.3 and 2.6 for nitrates and oxides, respectively.Notable effects of possible changes to respiratory tract model assumptions are (1) a reduction in the absorbed dose to target cells in the airways, if changes under consideration are made to the slow clearing fraction and (2) a doubling of absorbed dose to the alveolar region for insoluble forms, if evidence of longer retention times is taken into account.An important factor influencing doses for moderately soluble forms of Pu is the extent of binding of dissolved plutonium to lung tissues and assumptions regarding the extent of binding in the airways.For nitrates, this was due to the assumption of a bound fraction, and for oxides due mainly to the assumption of slower alveolar clearance.
This study highlights areas where more research is needed to reduce biokinetic uncertainties, including more accurate determination of particle transport rates and long-term dissolution for plutonium compounds, a re-evaluation of long-term binding of dissolved plutonium, and further consideration of modeling for plutonium absorbed to blood from the lungs.
Renate Winker-Heil for her support in modifying and using the IDEAL code for calculations in its latest version.