- 16 particle irradiation of deep respiratory tissue?, The last two columns in Table III describe the radiation field around such a particle in the lung using Geesaman's lung model? °, The dose rate to the entire organ is given in column 2 of Table III for comparison. From Table III it is Significant to note that with an assumed DF=1, the lung dose from the same particle varies by more than 8 orders of magnitude desending on whether one averages the dose over the entire lung or calculates it on the basis of the tissue exposed. Radiation Dose Rate Due to a Pu-239 Particl tv TABLE ,III (1 u in diameter, 0.28 pci?) Soft . Tissue 24 Irradiated Mass of Tissue Entire Orcan 99 Lung Tissue 5 Irradiated Clissest 6 20 Alveoli 0.4 ug 1000 g 65 ug 19 ug 735,000 0.0003 4000 11,000 Dose Rate (ren/yr) 21/ Geesaman, Donald P., 2. Amalvsis of the Carcinocenic Risk from an tUnsoluble Rlona-Enicting Aerosol Senosited in Dees Rasoiratory Tissue, CCRL-50337 trance Livermore Laboratory, and UCRL-50387 Addendun, Livermore, Calit., 1963.