ante ~ FA, “a /10 of that. A cell (ose nucleus is intercepted Lgec path of such @ par- c ‘Viele suffers sufficient injury that its capacity for cell division is usually gost (Bartfndson, A.W., 1962 and Bloom, W., 1959). . - The cancer inducing potential of plutentum is well known. One mc Wionth of a gram injected intradormally In rite)e has caused cancer (lisco, H., et al., 1947); a similar amount injected into the blood system c’ dogs has induced a substantial incidence of bone cancer (Mays, C.W., etal., 1947), because of plutonium's tendency to seek bone tissue. notely the body maintains a relatively effecti of plutoniuree into the blood system. Fortu- arrieraagainst the entry Also, because of the short range of the emitted helium nuclei, the radiation from plutonium deposited on the - - surface of human skin does not usually reach any relevant tissue. ‘Unfor- Before Jdescribe wry this is, I'd like to say sornething about the - characte stics of an acrosol. An aerosol is physically like cigarette smoke, or foz, or cement dust. “Because vf their small size, the particies coe comprising an aerosol remain suspended in air for long. periods of time. If an aerosol is inhaled, thea, depending on its physical characteristics, it: . may be deposited at different sites in the respiratory tree (Health Physics, ae 1966). JWarger a erosol sizes are usually rernoved by turbulence in the nose, particles deposited in the bronchial tree are cleared upward in hours by the - ciliated. mucus blanket thal covers the Structuce. This clearance system “@ugs not panctrate into the deep respiratory structures, the alveoli, where ' , ’ : hho parte oxygen-earbon dioxide exchange of tha dung takes place. Smaller 5 Tye So eyergagpernye ‘ lc aeBAN sy sted 4) ..