Abstract
Following brief, single exposures of dogs to an aerosol containing polonium it was found that 64% of the inhaled polonium was deposited within the animal. Thirty days after exposure the lungs contained 32–49% of the total body burden. In the interval 28–149 days post-exposure the biologic half-time for clearance of the lung was 36 days; that for whole body clearance was 37 days. Removal of the deposited dust appeared to be governed chiefly by the rate of removal of the polonium from the lungs. Fifty per cent of the deposited polonium was excreted in the first three days, the principal route being via the feces. Distribution patterns and estimates of radiation dose are presented.