Diel J H, Guilmette R A, Muggenburg B A, Hahn F F, Chang I Y
Lovelace Biomedical and Environmental Research Institute, Inc., Albuquerque, New Mexico 87185.
Radiat Res. 1992 Jan;129(1):53-60.
Beagle dogs were exposed once or repeatedly to 0.75-microns-diameter monodisperse aerosols of 239PuO2 by pernasal inhalation. The dogs that were exposed once received alveolar depositions (+/- standard deviation) of 3.9 +/- 1.9 kBq/kg body mass and accumulated doses of 23 +/- 8 Gy to the lung before death at 5.4 +/- 1.7 years after exposure. Dogs exposed repeatedly received a total alveolar deposition of 5.3 +/- 0.9 kBq/kg body mass during 7 to 10 semiannual exposures and accumulated doses of 22 +/- 5 Gy to the lung before death at 4.9 +/- 0.7 years after first exposure. Clearance of the plutonium from the lung in the dogs exposed repeatedly was slower than in the dogs exposed once. All dogs in the repeated-exposure study and all but one dog in the single-exposure study died from radiation effects. Pulmonary fibrosis accounted for 72% of the radiation-related deaths in the single-exposure study and 87% in the repeated-exposure study. The remaining dogs died with pulmonary cancer. Based on total cumulative radiation dose, the times after exposure to death from radiation pneumonitis and pulmonary fibrosis were not significantly different for single and repeated exposures. Thus dose rate does not appear to be an important factor in predicting death from radiation pneumonitis or pulmonary fibrosis for dogs inhaling 239PuO2.
将比格犬通过经鼻吸入的方式，单次或多次暴露于直径为0.75微米的239PuO2单分散气溶胶中。单次暴露的犬只肺泡沉积量（±标准差）为3.9±1.9 kBq/kg体重，在暴露后5.4±1.7年死亡前，肺部累积剂量为23±8 Gy。多次暴露的犬只在7至10次半年期暴露期间，肺泡总沉积量为5.3±0.9 kBq/kg体重，在首次暴露后4.9±0.7年死亡前，肺部累积剂量为22±5 Gy。多次暴露犬只肺部钚的清除速度比单次暴露犬只慢。多次暴露研究中的所有犬只以及单次暴露研究中除一只犬只外的所有犬只均死于辐射效应。在单次暴露研究中，72%的辐射相关死亡由肺纤维化导致，在多次暴露研究中这一比例为87%。其余犬只死于肺癌。基于总累积辐射剂量，单次和多次暴露的犬只因放射性肺炎和肺纤维化死亡的暴露后时间无显著差异。因此，对于吸入239PuO2的犬只，剂量率似乎不是预测放射性肺炎或肺纤维化死亡的重要因素。
