Depleted uranium ingestion

Table 2-8 shows the mass equivalents for natural and depleted uranium for radiation levels that caused potential radiological effects in rats exposed once for 100 minutes to airborne 92.8% enriched uranium with an estimated specific activity of 51.6 pCi/g (Morris et al. 1989). These mass equivalent values for natural and depleted uranium for the minimal concentration of radioactivity that is expected to induce potential radiological effects are well above levels that would be expected to be inhaled or ingested. In addition, the mass equivalents for natural and depleted uranium for potential radiological effects are 3,600 and 76,500 times higher, respectively, than the occupational exposure limits (short-term exposure) recommended by the National Institute for Occupational Safety and Health (NIOSH 1997). Therefore, MRLs for uranium based on studies that used enriched uranium are inappropriate. 

The most important uptake route for uranium is ingestion of food and drinking water, as shown in Table 26.1-2 (see Chapter 26.1, Section 26.1.7). The daily dietary intake of U for Ukrainian males is estimated at 7.8 mBq (Shiraishik et al. 1997), with typical daily intake values being 0.16 Bq for 0.0005 Bq for U, and 0.16 Bq for U. Military use of depleted uranium led to inhalation during combat and to shrapnel contamination (Bleise... 

As uranium has a density almost 70% higher than that of lead, ammunition made from this metal is an effective anti-tank weapon. When used in combat, the uranium in the bullet ignites upon impact and a cloud of uranium oxide dust is formed. To reduce the radiation risk, depleted uranium (DU) is used in weapon systems of this type. It is obtained as a residue when natural uranium has been enriched in respect of uranium-235. DU is a substance that is only about half as radioactive as natural uranium. But due to its radioactivity - even if it is low - the dust can cause internal injuries if it is inhaled or ingested. 

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