Biological monitoring for depleted uranium exposure in U.S. Veterans.
BACKGROUND
As part of an ongoing medical surveillance program for U.S. veterans exposed to depleted uranium (DU), biological monitoring of urine uranium (U) concentrations is offered to any veteran of the Gulf War and those serving in more recent conflicts (post-Gulf War veterans).


OBJECTIVE
Since a previous report of surveillance findings in 2004, an improved methodology for determination of the isotopic ratio of U in urine ((235)U:(238)U) has been developed and allows for more definitive evaluation of DU exposure. This report updates previous findings.


METHODS
Veterans provide a 24-hr urine specimen and complete a DU exposure questionnaire. Specimens are sent to the Baltimore Veterans Affairs Medical Center for processing. Uranium concentration and isotopic ratio are measured using ICP-MS at the Armed Forces Institute of Pathology.


RESULTS
Between January 2003 and June 2008, we received 1,769 urine specimens for U analysis. The mean urine U measure was 0.009 microg U/g creatinine. Mean urine U concentrations for Gulf War and post-Gulf War veterans were 0.008 and 0.009 microg U/g creatinine, respectively. Only 3 of the 1,700 (0.01%) specimens for which we completed isotopic determination showed evidence of DU. Exposure histories confirmed that these three individuals had been involved in "friendly fire" incidents involving DU munitions or armored vehicles.


CONCLUSIONS
No urine U measure with a "depleted" isotopic signature has been detected in U.S. veterans without a history of retained DU embedded fragments from previous injury. These findings suggest that future DU-related health harm is unlikely in veterans without DU fragments.
Dorsey
Carrie D
CD
Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Engelhardt
Susan M
SM
Squibb
Katherine S
KS
McDiarmid
Melissa A
MA
D004781:Environmental Exposure; D047830:Gulf War; D006801:Humans; D014481:United States; D014501:Uranium / Q000652:urine*; D014728:Veterans
D014501:Uranium