Rapid solubilization and translocation of 109CdO following pulmonary deposition

Abstract

In order to examine the translocation of CdO from the respiratory surfaces rats were given an intratracheal instillation of cadmium oxide tagged with 109Cd (primary particle size < 1.0 μm). The half-life of the 109Cd in lung was about 4 hr, at which time nearly 40% of the 109Cd body burden was in the liver. At 24 hr following instillation, the distribution of 109Cd (expressed as percentage of body burden, mean ± SD) was: lung, 23.9 ± 3.0; liver, 58.4 ± 3.9%; kidney, 2.7 ± 1.8%; and testes, 0.22 ± 0.02%. At 2 weeks after instillation the lung, liver, and kidney had 18, 57, and 8%, respectively, of the body burden. Less than 10% of the instilled 109Cd was excreted during the first 2 weeks. These data suggest that inhaled CdO is highly soluble in the lung but that cadmium is slowly excreted from the body, resulting in a long-term dose commitment to several tissues.