Figure 1.

Estimation of current urinary DU excretion from DU oxides absorbed 18 years earlier. From the Human Respiratory Track Model (HRTM) for inhalation of uranium oxides we estimated the daily urinary excretion of DU, expressed as a fraction of the original inhaled dose (log scale), and plotted as a function of days since inhalation (log scale). In the sample of veterans studied, the duration between potential inhalation (in the first half of 1991 during the conflict) and the urine collection (November 2008–June 2010) was 6720 ± 365 days or 18.4 ± 1.0 years, shown as the width of the small red box. The analogous region from Dorsey et al.²⁰ discussed in the text is shown in the larger blue box. Three curves showing fractional uranium excretion predicted by the combined dissolution-storage-excretion function of the HRTM for uranium oxide particulates are shown; these represent “Low” and “High” absorption curves during dissolution and metabolism of compounds of uranium oxide with contrasting chemical form and solubilities. The figure is modified from^8,24 using the HRTM model with aerosol and oxide physicochemical characteristics summarized⁸ and taking into account the uncertainty in the HRTM model parameters²³.