title: Lung response to localized irradiation from plutonium microspheres.
abstract: Uniform spherical 10-micrometer diameter particles of ZrO2 ceramic, containing various concentrations of PuO2, have been injected into the jugular vein of Syrian hamsters with subsequent permanent lodgement in the lung capillaries. The number of particles injected has varied from 2000 to 2 000 000 and the specific activity has been from 0.16 to 59 pCi/sphere so that lung burdens range from 0.2 to 700 nCi. To date, approximately 3000 hamsters have been committed to the experiment and two-thirds have died--the expected rate for normal animals. Little biological damage has been observed, and only five primary lung tumours have been found that may be due to radiation delivered to the lung. To provide a comparison to more uniform radiation, soluble polonium has also been instilled intratracheally. Results from the microspheres suggest that localized lung irradiation alone is not sufficient cause for tumour induction and is much less hazardous than diffuse exposure.
mesh_terms: D000818:Animals; D006224:Cricetinae; D008168:Lung / Q000528:radiation effects*; D008175:Lung Neoplasms / Q000209:etiology*; D008647:Mesocricetus; D008863:Microspheres; D009374:Neoplasms, Experimental / Q000209:etiology; D009381:Neoplasms, Radiation-Induced; D011005:Plutonium
chemical_list: D011005:Plutonium