The remainder of this chapter contains the committee’s conclusions and recommendations. The next section describes four approaches to assessment of health outcomes in DU-exposed military personnel and veterans and the committee’s conclusion regarding the approach most likely to obtain useful information about DU-related health outcomes in this population. The chapter concludes with recommendations aimed at improving future epidemiologic studies and identifying current active-duty military personnel and veterans with potential DU exposure.
As summarized in Table 4-1, the committee examined four general approaches to study health outcomes related to DU exposure in military and veteran populations. Two of the study designs use existing data, and two require new data collection.
The first approach is a case-control study that uses existing data. The study population would be drawn from Department of Defense (DOD) and Department of Veterans Affairs (VA) health records and registries. Cases would be selected on the basis of a health outcome identified as having high priority for further study by the committee in its report Gulf War and Health: Updated Literature Review of Depleted Uranium (IOM, 2008). That report contains an extensive review of the scientific literature on long-term health outcomes of exposure to natural uranium and DU in several populations, including uranium-processing workers, people whose drinking water contains high concentrations of uranium, and Gulf War veterans. Although the committee’s overall conclusion is that the data are inadequate and insufficient to determine whether an association between exposure to uranium and a number of long-term health outcomes exists, it judged that several health outcomes should be given high priority for further study: lung cancer, lymphoma, renal disease, respiratory disease, neurologic outcomes (including neurocognitive outcomes), and adverse reproductive and developmental outcomes. Prior DU-exposure history would be assessed through a variety of means, including urinalysis, existing questionnaires, and interviews. Several limitations are associated with this approach, including a potentially small number of cases because of the low rate of disease occurrence and the low prevalence of exposure to DU. In addition, the followup time may be too short to capture some health outcomes because of their latency.
The second approach, similarly, uses a case-control study design but adds collection of new data by including future cases of disease and appropriate controls. Thus, the study population would be expanded by prospectively adding new cases with health outcomes of interest and controls from military personnel in war theaters where DU is or will be in use. Information about exposure to DU before the development of diseases and outcome data would be collected