Laskin, et al, indicate a significant carcinogenic response in the lung at 1400 . 5G t . oss Gcesainan indicates lung is of ~ suggesting a comparable sensitivity - of lung tissue”™”~. time in the rem, . “ . ; the order of cne vear™’. Rh ; that the tissue repair ro 5 7 .It therefore seems appropriate, but not necessarily conservative, to accept as guidance that this enhanced cancer risk cccurs when particles irradiate the surrounding lung tissue at a dose rate of 1000 rem/yr or more. TABLE IV Particle Activity and Size to Give a Dose of ral 2060 rem/year to the Surrounding Lung Tissue Particle Particle Diameter npc) 239 Bu. alveoli) 0.14 0.8 0.12 1/2max inflated ( 68 alveoli) 0.07 0.6 0.09 Closest 20 alveoli 0.02 0.4 0.06 3/4 max intlated 56/ Laskin, 57/ Geesaman, 58/ Ibid (138 . et al, Op. (u)?? 238pu0> cit. ll. cit., p. Donald P., UCRL-50387, Op. Based upon specific activity given by Langham, W.H., 59/ Op. cit., p. 7. . oe sok ' Tek "Says, pater Rr . "aug oO, ao. : Jp eM OY ‘f . . tet: St 4 F, jd abl . “in weeety RIE,aR rr . ot Ley Boag . sa . 5 t es sta 18.4 Ee 1 7a]kaa- 32 ae : web . ofatt at Gead pels SaaS Be ee ay , . Ma a = yg ‘ « aro . : vote ue th gate ta eae soe eS ae ote me Bg rea ejits i . 4 , oa VeMatas aay ooh‘ oS PS eg wo, Uo A - 8 ; r ere oete.bo ie