Longitudinal Health Surveillance in a Cohort of Gulf War Veterans 18 Years After First Exposure to Depleted Uranium

As part of a longitudinal surveillance program, 35 members of a larger dynamic cohort of 79 Gulf War I veterans exposed to depleted uranium (DU) during combat underwent clinical evaluation at the Baltimore Veterans Administration Medical Center. Health outcomes and biomonitoring results were obtained to assess effects of DU exposure and determine the need for additional medical intervention. Clinical evaluation included medical and exposure histories, physical examination, and laboratory studies including biomarkers of uranium (U) exposure. Urine collections were obtained for U analysis and to measure renal function parameters. Other laboratory measures included basic hematology and chemistry parameters, blood and plasma U concentrations, and markers of bone metabolism. Urine U (uU) excretion remained above normal in participants with embedded DU fragments, with urine U concentrations ranging from 0.006 to 1.88 g U/g creatinine. Biomarkers of renal effects showed no apparent evidence of renal functional changes or cellular toxicity related to U body burden. No marked differences in markers of bone formation or bone resorption were observed; however, a statistically significant decrease in levels of serum intact parathyroid hormone and significant increases in urinary calcium and sodium excretion were seen in the high versus the low uU groups. Eighteen years after first exposure, members of this cohort with DU fragments continue to excrete elevated concentrations of uU. No significant evidence of clinically important changes was observed in kidney or bone, the two principal target organs of U. Continued surveillance is prudent, however, due to the ongoing mobilization of uranium from fragment depots.