John W. Gofman released two papers recently on behalf of the Committee for Nuclear Responsibility. Using what is in effect an extension of the "hot particle" hypothesis, he defines the critical tissue in lung of humans to comprise 1 gm of bronchiolar epithelium which has a 500-day half-life for clearance of a small portion of inhaled plutonium particles which deposit on or become trapped on this epithelial region of the lung after clearance from alveoli. The effect is to extend to the sensitive bronchiolar region a long-term burden of inhaled plutonium. The slowed clearance is presumed by Gofman to be the result of impaired ciliary activity because of smoking. His hypothesis is invalidated by recognition that if it were true smokers would eventually accumulate sufficient cigarette smoke residue in the lungs to cause blockage of small airways and cessation of ventilation. Gofman's use of "lung cancer dose" in his risk analyses is misleading and obscures reality;for example, the risk from natural background radiation is projected to be considerably greater than for fallout plutonium when analyzed using Gofman's approach.
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