Radiological conditions in areas of Kuwait with residues of depleted uranium. Report by an international group of experts

Depleted uranium (DU) is one of the by-products of uranium enrichment and, like any other uranium compound, has both chemical and radiological toxicity; it is mildly radioactive, having about 60% of the activity of natural uranium. DU has had a wide range of peaceful applications, such as the provision of radiation shielding for medical sources or as counterweights in aeroplanes. DU is also used for heavy tank armour and, owing to its high density and high melting point and its property of becoming 'sharper' as it penetrates armour plating, in anti-tank munitions and missiles. The 1991 Gulf War was the first conflict in which DU munitions were used extensively. In view of the concerns raised about the possible link between human exposure to ionizing radiation from DU and harmful biological effects, the Government of Kuwait, in February 2001, requested the IAEA to conduct surveys at and assessments of a number of specified locations. The aim of this work was to inform the Government of Kuwait and the public of the possible radiological conditions arising owing to DU residues at these sites. The IAEA accepted the request for a radiological assessment under its unique statutory functions within the United Nations system, namely: (1) to establish standards of safety for protection against radiation exposure; and (2) to provide for the application of these standards. In 1996 the IAEA, in cosponsorship with other relevant organizations in the United Nations system, established the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. These standards are fully applicable to exposure to all forms of ionizing radiation, including exposure to any uranium radionuclides in general and, in particular, to DU. In the past, a number of evaluations of the environmental and health impact of DU munitions have been performed by national and international organizations. This report constitutes the first comprehensive radiological assessment of compliance with international radiation protection criteria and standards for areas with residues of DU munitions that has been carried out under the auspices of the IAEA. The IAEA assembled an international team of senior experts, including a representative of the United Nations Environment Programme (UNEP). The team was led by R.H. Clarke, Chairman of the International Commission on Radiological Protection.The experts visited Kuwait in September 2001 to assess the sites identified by the Government of Kuwait and to evaluate the available information. The 11 locations selected for the investigation included sites of military action during the Gulf War in which DU munitions were used, sites where DU residues still exist and areas where concern has been expressed about the possible contamination of water and foodstuffs with DU. In February 2002 a mission was conducted to collect samples at the identified sites.The sampling team included scientists from the IAEA Secretariat and from the Spiez Laboratory in Switzerland, representing the UNEP, together with experts from the laboratory of the Radiation Protection Department of the Ministry of Health of Kuwait. Around 200 environmental samples, including soil, water and vegetation, were collected during the campaign and subsequently analysed. The international team of experts prepared a report describing the findings of the measurement programme and the subsequent assessment performed by the team. This report provides a detailed description of the IAEA's investigation of the radiological conditions in Kuwait in relation to residues of DU, the results of the radiological assessment, the overall and site specific findings and conclusions of the assessment, and the recommendations of the expert group. On the basis of the measurements carried out at the sites investigated in the IAEA's study and summarized in this report, DU does not pose a radiological hazard to the population of Kuwait. No persons who might receive doses from exposure to residues of DU have been identified, either by the authorities of Kuwait or in the IAEA's investigation. Annual radiation doses that could arise from exposure to DU residues would be very low and of little radiological concern. Annual radiation doses in the areas where residues do exist would be of the order of a few microsieverts, well below the annual doses received by the population of Kuwait from the natural sources of radiation in the environment and far below the reference level recommended by the IAEA as a criterion to help establish whether remedial actions are necessary. Complete DU penetrators or fragments can still be found at some locations where DU weapons were used during the Gulf War, such as at the oilfields at Manageesh. Prolonged skin contact with these DU residues is the only possible exposure pathway that could result in exposures of radiological significance. As long as access to the areas remains restricted, the likelihood that members of the public could pick up or otherwise come into contact with these residues is low. The authorities of Kuwait have the competence and equipment to carry out the necessary monitoring and survey activities in relation to DU. The analysis techniques used by the Radiation Protection Department of the Ministry of Health of Kuwait are sufficient to determine whether concentrations of uranium in environmental samples are of radiological concern