Toxicity of inhaled 238PuO2 in Beagle dogs. A. Monodisperse 1.5 μm AMAD particles. B. Monodisperse 3.0 μm AMAD particles. IX

Beagle dogs have received an inhalation exposure to one of two sizes of monodisperse aerosols of 238PuO2 to achieve graded levels of initial lung burden. All dogs are being studied over their life span. Eighty-two dogs have died with initial lung burdens ranging from 0.02 to 1.5 μCi 238Pu per kilogram body weight; eight died with radiation pneumonitis and pulmonary fibrosis, four died with lung tumors, 61 died with bone tumors, one died with a liver tumor and seven died due to miscellaneous causes. Four control dogs have died. Sixty-two exposed and 20 control dogs are surviving at 2021 to 2849 days after inhalation exposure