Some soldiers inhaled it when they pulled wounded comrades from tanks hit by D.U. veterans were unknowingly exposed to potentially hazardous levels of depleted uranium, or uranium-238, in the Persian Gulf. troops were exposed to dangerous levels of D.U., a two-month investigation by The Nation has discovered that hundreds and perhaps thousands of U.S. Yet despite Pentagon assurances that only a small number of U.S. The first time the Army used this “depleted uranium” (D.U.) ammunition on a battlefield was during the Gulf War, in 1991. Research support provided by the Investigative Fund of the Nation Institute.