Objective: A population of Gulf War I veterans sustained inhalational exposure to aerosolized depleted uranium (DU) oxides in 1991 during US military friendly-fire incidents. Subsequent exposure modeling simulating the inhalational exposures suggested that insoluble DU oxides may persist in the lung and thoracic lymph nodes, creating a chronic local risk from radiation and chemical toxicities from uranium. Some members of this population continue to excrete depleted uranium in the urine 20 years later. We evaluated whether those with high body burdens of uranium were more likely to have pulmonary health abnormalities compared to those with low body burdens.

Methods: We compared self-reported respiratory symptoms, mean pulmonary function values, and prevalence of low-dose chest CT abnormalities between high and low urine uranium (uU) groups.

Results: We found no significant differences in respiratory symptoms, abnormal pulmonary function values, or prevalence of chest CT abnormalities in high versus low uU groups. Overall, the cohort’s pulmonary function values fell within the expected clinical range. Two-thirds of the entire cohort demonstrated intraparenchymal pulmonary nodules ≥ 3mm in size. Over a third demonstrated evidence of airways disease not isolated only to smokers, with either mosaicism, large airway thickening or emphysema.

Conclusions: Our results support previous estimates that the DU levels inhaled during the 1991 friendly-fire incidents likely do not cause long-term adverse pulmonary health effects. The presence of small pulmonary nodules may not be of clinical significance, as the expected prevalence of small pulmonary nodules in the general population is not known. As new cohorts of military members who share similar deployment-related environmental exposures are evaluated, findings from this deployed population may assist in further understanding expected respiratory outcomes.

This work is funded by the US Department of Veterans Affairs.