Exposure to depleted-uranium aerosols can be affected by characteristics of the struck vehicle, impact conditions, and residence time of personnel in the contaminated vehicle. If the target is soft (such as a lightly armored vehicle), the depleted-uranium penetrator is likely to pass through it with little conversion of the penetrator rod into depleted-uranium oxides (Royal Society, 2001). If a penetrator strikes the depleted-uranium armor of a modern battle tank, much of the penetrator mass will be converted into depleted-uranium oxides. When a modern battle tank, such as an Abrams tank, is involved in a “friendly-fire” incident, substantial amounts of depleted-uranium aerosols can be generated by the impact.
During friendly-fire incidents, various exposure scenarios occurred. To categorize the exposure levels, exposures to depleted uranium during the Gulf War have been classified into three categories (DOD, 2000; USACHPPM, 2000), which provide a useful framework for considering potential depleted-uranium intakes and associated risks that was used in the Capstone report (USACHPPM, 2004), the Sandia report (Marshall, 2005), and the Royal Society report (Royal Society, 2001). The three categories are defined here.
Level I includes military personnel in, on, or near combat vehicles at the time of impact and perforation by depleted-uranium munitions or personnel who entered vehicles immediately after they were struck (and perforated) by depleted-uranium munitions. The personnel could have been exposed to depleted uranium by contact with fragments resulting from impact or their being embedded in the body, by inhalation of depleted-uranium aerosols, by ingestion of depleted-uranium residues, or by settling of depleted uranium particles on open wounds, burns, or other breaks in the skin—or by any combination of these possibilities. This level also includes personnel occupying a vehicle whose depleted-uranium armor is perforated by non–depleted-uranium munitions.
Level II includes military personnel and a small number of Department of Defense (DOD) civilian employees whose job functions required them to work in and around vehicles that contained depleted-uranium fragments and particles. Those people were not in a vehicle at the time of impact and did not immediately enter it after it was struck. They performed a variety of tasks, such as battle-damage assessment, repairs, explosive-ordnance disposal, and intelligence-gathering. They typically entered vehicles well after the initial suspended aerosol had dissipated or settled onto interior surfaces. They may have inhaled depleted-uranium residues that were resuspended by their physical activities, ingested depleted uranium through hand-to-mouth transfer, or spread contamination on their clothing. DOD personnel who were involved in cleaning up depleted-uranium residues generated during other events, such as the July 11, 1991, explosion and fires at the Camp Doha North Compound, are also included in this group.
Level III is an “all others” group whose exposures were brief or incidental. This group includes personnel who entered depleted-uranium–contaminated Iraqi equipment, were downwind of burning Iraqi or US equipment struck by depleted-