Spatial and temporal distribution of PuO2 aerosol particles deposited in rodent lungs by inhalation

For an understanding of the effect on lung tissue of insoluble PuO2 particles deposited in deep lung, the extremely short range of the emitted alpha particles makes it imperative to know the local distribution of the particles as a function of time after inhalation. In addition, the effectiveness of lung lavage as a means of removal of insoluble PuO2 particles from the lung may depend on the distribution of the particles remaining as well as on the fraction remaining. Preliminary data have been obtained on the local distribution of 238PuO2 particles of 0.8 μm AD in the lungs of Syrian hamsters as a function of time after exposure by inhalation. Data are included for a hamster that received bronchopulmonary lavage. Studies have been started to determine the effect of particle size and specific activity on the local distribution using 238PuO2 and 239PuO2 particles of 0.8 and 2.8 μm AD in Fisher-344 rats. A method has been developed using the local distribution measured from autoradiographs of multiple cross sections of lung to estimate the fraction of lung at risk from the PuO2 particles