+ . ac ~, Tek OF . eo ua =~ : hag abil wok Pe wee sos ho? o- a oseT os 2. ie re eee BSc ps a ia. < 45' . elPa st enpe slo . 7 ree . ac os ee et ey ty Me we oy pte bes eba Bee NAS-NRC. fts conclusions $5, ST) modifthe ecarllcr once sUghth. but to essence canfirm ine pecveased cancer risk for ramers in the 12-359 CWLM renee. A rosdiied cestton is taken on the rois of cigarette saabine Ae miners tend to be ubteutious and heavy smokers, it had been ditioule to finda3 7 ’ suficivat Muebcr OFonsmukers to UC Contra” the Gata. klowever, | y Vaae arifeltagenes Renoari. it is comvluced that cigarette smoking does not acceunt fer the excess incidence of cancer.? Also, the Interagency group idenufied certain biases In Carer work that indeate that the exposure levers mav have been everestimeated. Thus, the 120-389 CWLM category mayactually be lower. The hisiologcal cell tyee of bronvhiolar carcinoma 16 Uranilm Murer: nes ceen seported to be marked), diverent from that in the general poposaticn 4S). smaii celiunlelerentiated tres of tumers (2A. and 2B under the WHO Sass ina. tion scherie) predominate among uranium miners. To verify this arnt Jeoendent pane! of pathaionists reviewed the nistologic material recently (55). Ves: a few minor disagreements this panel confirmed the earlier relative predsmicarce of small cell and undifferentiated cell types. This may or may not be srecifc ta radiation exposure. Current examination of other hard rock miners. Zoorspar miners, iron miners, coal miners, etc., indicates that manyof these, to.>. show an excess of undifferentiated cell tumors. But neither are radon and its daughter products necessarily absent in these environments. Animal studies in this feld have provided support for, and exvens 3 = gf the deia on human exnosees and puzzling contradictions to the humai ¢.t3a. Or. contradiction has been the difficulty in producing bronchogeric <arc.ncome in animals by exposure to radon itself (19, also Morken, persona: cons rumcanan:. although prenecplastic change is suspected. The inductien of lunz cancer bs nuchdes in ihe Gaughter product chain is not sertously doubted. | iueed. Cine. Berke & Mull (60) show that 7!°Po is a very effective agent in trodack che cu wer icats. Stuart and others in the Battelle-Northwest group have veer expousr2 lar sttr3 and Cogs to various mixtures of radon daughters, urantor creuo te. exhaust fernes, and cigareite smoke (61-63). Ear'y results ($13 show Sponge hvperplasia but no significant d.fterences among the groums 2: vet. Kilibarda et al (64) found that cadon (at 7.36 x 1078 Cil, did no the development of silicotic nodules or otherwise significantly modify the ‘cre th 2 ttl . . Teteue aie mae de y:Ife aa bq eee pathologic picture of rats rece:ving radon and SiO, simuhareoush. 7h eurher Wark by French wuihors. fiowever, the me OF vosti\e nds was a tL snort. A oreiiic Tilerature has developed, much of tt during the per cd oJ ib TRVILN., Om oa Composition, transleceuon, and excretion of cadon and vs severs' taugiver be TR. ie ' io. Ses for Cas Gunton sew are setvers clagr Mor large geeutoul. ny soca sew tk Sane poo yaorpa bas bacco ada owes sr. eam ostuLa tho cureses Ga oc. Lote ee? tM tae oF “aad oot, be a , . a ead, PPE ne Sb NE hE EB 7 po ’ ‘ye ae Payment, * wood efRerey aes s cH gg : 4 i Troe } ree ote | ot i ae a hey1 . ao Syoea Creeley ‘ af ee 3 tH a Og aa "oa,rhe ee ' cat His tae , Le : : : ' tae Doct tet ea eh ops yt moe bee oy wreypecsen OF eh eet a Capes AT DiCeh cS OT STs TAY Nas OCU bak Iho eontadit, eth “ye cches : ote te yea te i ie tev meas a@y eree iver? be wot vio ed usge se what tomuitive, since there Is mat Eee aoe intent COICO HA IL a EFS ARSEEFBRATARREARSMITER22TEIag ea " tbe aEe : 7 ge ' f eg Beg Nt re Boe eee ne - “. red cr. “hohe yd * t ' 4 eo “ooh, wes at « 1? ae Se ads oo rgd core . are et yo de hd . hot oone toy . ma i ate . . Abate RS ADec ¥ » ” } Gage , ue L R s we a . os yt , eB ene ack ea . le el ‘ * ‘ Uy fase rere, r BPS RE Pape PSB yphl nerd picky te TE te Noma alte3 sett 7 ‘ 7 a ook yg pt hea a FE . . —_— . Se LAME Gat . . ee re se gat - aT ate Weg eo Poyee ae ap be ta