Status of Health Concerns about Military Use of Depleted Uranium and Surrogate Metals in Armor-Penetrating Munitions

The use of depleted uranium in armor-penetrating munitions remains a source of controversy because of the numerous unanswered questions about its long-term health effects. Although there are no conclusive epidemiological data correlating depleted uranium exposure to specific health effects, studies using cultured cells and laboratory rodents continue to suggest the possibility of genetic, reproductive, and neurological effects from chronic exposure. Until issues of concern are resolved with further research, the use of depleted uranium by the military will continue to be controversial. Meanwhile, there are military programs to find substitutes for depleted uranium in munitions. Although a wide variety of alloys are being evaluated by munitions developers, certain alloys of tungsten have been developed that demonstrate properties very close to the ones that make depleted uranium useful in armor-penetrating munitions. One hundred and fifty years of industrial experience suggest that tungsten and tungsten alloys are not a significant health risk except in certain industrial exposure scenarios. However, recent research has shown that some of the most promising militarily relevant alloys of tungsten exhibit unexpected long-term toxicities as embedded shrapnel. Rats implanted in their leg muscles with pellets made from a particular alloy of tungsten, nickel, and cobalt, considered a promising surrogate for depleted uranium in munitions, develop aggressive rhabdomyosarcomas within 6 months of implantation that metastasize to the lung and necessitate euthanasia of the animals. One hundred percent of the tungsten alloy-implanted rats were affected. Immune system changes independent of tumor development were also observed. These findings amplify the need to investigate substances of questionable toxicity early in munitions development, especially with regards to the unusual kinds and levels of exposure that might be expected by the military. 1.0 INTRODUCTION Advances in metallurgy and weapons design in the past several decades have led to new munitions whose effectiveness has provided tactical advantages on the battlefield and consequently, saved lives of personnel. However, decisions to deploy these munitions have sometimes outpaced our knowledge of how they impact the health of those exposed to them. Paper presented at the Human Factors and Medicine Panel Research Task Group 099 “Radiation Bioeffects and Countermeasures” meeting, held in Bethesda, Maryland, USA, June 21-23, 2005, and published in AFRRI CD 05-2. NATO RTG-099 2005 21–1 Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 2005 2. REPORT TYPE 3. DATES COVERED 4. TITLE AND SUBTITLE Status of Health Concerns about Military Use of Depleted Uranium and Surrogate Metals in Armor-Penetrating Munitions 5a. CONTRACT NUMBER