[en] The pathology associated with the inhalation of plutonium was studied in beagle dogs given a single exposure to aerosols of ²³⁹PuO₂, ²³⁸PuO₂, or ²³⁹Pu(NO₃)₄. The temporal-spatial relationships between plutonium deposition and the development of lesions in dogs were evaluated up to 11 years, 8 years, or 5 years, respectively, after exposures, resulting in initial lung burdens ranging from ∼2 to ∼5500 nCi. Exposure of the lung to high dose levels produced a spectrum of progressively more severe morphological changes, ranging from radiation pneumonitis to fibrosis. Lung tumors occurred at exposure levels that did not result in early death from radiation pneumonitis or fibrosis. Bronchiolar-alveolar carcinomas, papillary adenocarcinomas, epidermoid carcinomas, and combined epidermoid and adenocarcinomas were observed. Sclerosing tracheobronchial lymphadenitis, radiation osteodystrophy, osteosarcoma, and hepatic adenomatous hyperplasia were the principal extrapulmonary lesions resulting from translocation of plutonium. 15 refs., 2 tabs