Levels of depleted uranium in Kosovo soils

The United Nations Environment Programme (UNEP) has performed a field survey at I I sites located in Kosovo. where depleted uranium (DU) ammunitions were used by the North Atlantic Treaty Organization (NATO) during the last Balkans conflict (1999). Soil sampling was performed to assess the spread of DU ground contamination around and within the NATO target sites and the migration of DU along the soil profile. The U-234/U-238 and U-235/U-238 activity concentration ratios have been used as an indicator of natural against anthropogenic sources of uranium. The results show that levels of U-238 activity concentrations in soils above 100 Bq.kg(-1) can be considered a 'tracer' of the presence of DU in soils. The results also indicate that detectable ground surface contamination by DU is limited to areas within a few metres from localised points of concentrated contamination caused by penetrator impacts. Vertical distribution of DU along the soil profile is measurable up to a depth of 10-20 cm. This latter aspect is of particular relevance for the potential risk of future contamination of groundwater.