These data show that what is high in one area may be normal in another but that areas with higher rates do not have known resulting adverse health consequences. Given that depletion of uranium does not alter its chemical properties, and that radiation from DU is less than from natural uranium, exposure to DU at these levels would appear not to have known adverse health consequences. Lung damage Lung damage resulting from inhalation of uranium oxides is usually noncancerous alveolar epithelium damage of type II cells. Animal studies have also examined pulmonary damage from exposure to uranium oxides. Alpha radiation doses were estimated to have been greater than 500 rads in the lungs and greater than 7,000 rads in tracheobronchial lymph nodes.
Lung fibrosis is consistent with relatively short-term high exposure rate in animal experiments.
Outside the military or industrial settings, the major portion of the natural body burden of uranium for typical civilians is derived from ingested and inhaled material. There is a limited amount of natural uranium in the air we breathe, the food we eat, and water we drink. The schematic in Figure 2.2 depicts how uranium interacts with the body. Inhaled, ingested, or embedded fragments reach the blood after solubilizing either at the site of entry or at some other location in the body where they end up. For instance, some inhaled uranium enters the blood from the lungs, and some of the uranium originally in the lungs ends up in the gastrointestinal tract as a result of mucociliary clearance from the respiratory tract and subsequent swallowing.