Regional deposition of inhaled 137 Cs-labeled monodisperse and polydisperse aluminosilicate aerosols in Syrian hamsters.

Two groups of eighty Syrian hamsters were exposed to aerosols of 137Cs-labeled fused aluminosilicate particles. One group was exposed to a monodisperse aerosol with AMAD (activity median aerodynamic diameter) of 1.53 micron and sigma g (geometric standard deviation) of 1.15. The other group was exposed to a polydisperse aerosol with AMAD of 1.87 micron and sigma g of 1.46. After exposure, the hamsters were killed and carefully dissected and tissues were assayed for 137Cs to determine regional deposition of the inhaled aerosols. The relative lung deposition was similar for the two groups and was estimated as 9.5% of the inhaled aerosols. The right apical lobe consistently contained more activity and the right cardiac and right diaphragmatic lobes less activity on a per gram lung weight basis than the total lung.