The U.S. Department of Defense claims that no human cancer of any type has been seen as a result of exposure to either natural or depleted uranium. Militaries have long had risk-reduction procedures for their troops to follow, and studies are in consistent agreement that veterans who used DU-enhanced munitions have not suffered, so far, from an increased risk of cancer (see the Gulf War and Balkans sections below). The effects of DU on civilian populations are, however, a topic of intense and ongoing controversy.