The Distribution of Inhaled Plutonium-239 Dioxide Particles Within Pulmonary Macrophages

Abstract

Pulmonary macrophages and radioactive plutonium dioxide particles were removed from the lungs of rats by lung washing following inhalation of ²³⁹PuO₂ particles. Plutonium particles were rapidly phagocytized and retained within pulmonary macrophages for extended periods of time. Phagocytic indexes correlated well with the log ²³⁹pu content of the lung from one hour to 25 days after exposure. As much as half of lung- deposited plutonium could be removed from the lung by serial saline washing, the amount depending on the amount of plutonium inhaled and the time since inhalation. The greater the amount of plutonium in the lung, the earlier and more severe were the pathological alterations, resulting in less effective removal by lung washing. The removal of inhaled radioactive particles by lung washing is a useful experimental technique and may be of therapeutic value.