TAB F – World Health Organization Depleted Uranium Monograph: "Depleted Uranium Sources, Exposure and Health Effects" ^[83]

Summary. This monograph is a scientific review on depleted uranium and is part of the World Health Organization's (WHO’s) ongoing assessment of the possible health effects of exposure to chemical, physical, and biological agents. It addresses environmental health questions about the possible health consequences to populations residing in conflict areas where depleted uranium (DU) munitions were used. While the main purpose is to examine health risks that could arise from exposure to DU, the monograph is also intended as a desk reference providing useful information and recommendations to WHO member states so that they may deal appropriately with the issue of DU and human health.

Key Points. Due to the wide variation in possible exposure scenarios, the WHO recommends a tiered approach to exposure assessment: Tier 1, a desk assessment; Tier 2, a field study and analysis; and Tier 3, a detailed site-specific exposure assessment. The monograph recommends three echelons of protective measures:

• Locality-based: taken when the data are insufficient to determine if individuals are being exposed to DU, but exposure is probable. Calls for general advice to reach a broad cross section of the population.
• Environment-based: taken when sampling and survey results demonstrate excessive levels of DU in a specified environmental medium (e.g., air, water, food, soil). Calls for limiting human and animal exposure to the contamination.
• Medical-based: taken when medical results confirm that a person’s health is being, or is likely to be, compromised by DU exposure. Since no biomarker is specific to DU, care must be taken not to overlook other potential causes of adverse health effects. Could call for a variety of medical tests.

Health prognosis: "For chronic exposure at low uranium levels no permanent damage has been reported. Occupational exposure of uranium mine workers is not known to have been detrimental to their health; only a few have developed transitory anaemia. Soldiers who have incorporated uranium fragments have not shown any renal problems. The radiological hazard is likely to be very small. No increase of leukemia or other cancers has been established following exposure to uranium or DU."

• "For the general population, neither civilian or military use of DU is likely to produce exposures to DU much above normal background levels produced by uranium."
• "Under most circumstances, use of DU will make a negligible contribution to the overall natural background levels of uranium in the environment. However, levels of DU may be significantly raised over background levels in close proximity to DU contaminating events."
• "Measurements of DU in conflict areas indicate only localised (within a few tens of metres from impact site) contamination at the ground surface. However, levels of contamination in food and drinking water could rise after some years and should be monitored where it is considered that there is a reasonable possibility of significant quantities of DU entering the ground water or food chain."
• "Where possible, clean up operations in impact zones should be undertaken where there are substantial numbers of radioactive particles remaining and DU contamination levels are deemed unacceptable by qualified experts."
• "Young children could receive greater exposure to DU when playing in or near DU impact sites. Typical hand-to-mouth activity could lead to high DU ingestion from contaminated soil. Necessary preventative measures should be undertaken."
• "General screening or monitoring for possible DU related health effects in populations living in conflict areas where DU was used is not recommended."

The monograph also identified areas for research that would significantly enhance knowledge and lead to better assessments of health risks from exposure to DU. "In particular, studies are needed to clarify our understanding of the extent, reversibility and possible existence of thresholds for kidney damage in people exposed to DU." A lack of information was noted about the possible biological action of uranium or DU in the areas of neurotoxicity, reproductive and developmental effects, hematological effects, and genotoxicity.