In addition to inhalation intake, depleted-uranium shrapnel wounds constitute a potential exposure route for those involved in level I exposure scenarios. In the Gulf War, 6 Abrams tanks and 15 Bradley vehicles were involved in friendly-fire incidents. The total number of soldiers surviving those incidents was 104. The Baltimore Department of Veterans Affairs health-surveillance program recruited and followed this depleted-uranium–exposed cohort. A total of 74 soldiers have participated in at least one visit since 1993. Of the 74, 19 have evidence of retained shrapnel as indicated by skeletal X-ray analysis.

Whole-body radiation counting was conducted in 29 depleted-uranium–exposed soldiers, including those with shrapnel (McDiarmid et al., 2000). Only nine have detectable scores above the background provided by the counting chamber, and all nine had shrapnel. The lack of sensitivity may be due to the low radioactivity of uranium and the tissue absorption of depleted-uranium radiation.

Another way to estimate uranium exposure is on the basis of urinary uranium excretion. Urinary uranium concentration can be a biomarker of total cumulative dose. An occupational-exposure decision level of 0.8 μg/L is used by the Department of Energy Fernald Environmental Management Project (FEMP, 1997). The