Document dDQQ73ry4Rr5m61m4d83r6w7Q

<i , . >' PLAINTIFF'S EXHIBIT UC-3S4S y WitjTUL Tzi ^ * * * * **f \ SUBJECT: Asbestos Cancer tlazard FROM: Roy E." 'Albert, 'Chairman Carcinogen Assessment Group TO: Joseph Padgett, Director Strategies and. Air Standards Division This is in response to your memorandum of May 3, 1978 requesting CAG assistance in determining naethcr EPA should ... . JJ regulate taconito as an asbestos cancer hazard. .In our opi-iTon the ansver should be in~th a^-fJj^ative. The attached report by Dr. Cook summarizes "thepresent state of knowledge. In essence, there is suggestive evidence that shott fiber lengths of asbestos may".not--txfaTQgenic ~oF carcinogenic .. far as^iuesotheiioma is concerned but the evidenco is not . 0 decisive and there is no evidence one way or the other ' regarding the effect of fiber length on. the induction of bronchogenic cancer which is the main health hazard..._ . Attachment Coagdc;; .* >. '`T.-.v"**-*'':'.* cc: S. Gage S. Jellinek Tf. Barber H. James R. Carton E. Anderson CRU/2 copies CAG Reading ... . ; ' -'/ " - T - ~ ' ' : ./ . ' EAnderson/dj/6/27/78 .s ' . ' "Ti r1*?: B . " Tr-1 *~ . K\ 1 UCC 007438 AJ0 * I t r i I. I I i I 1I i V 1 r .. ?i i i i ASSESS!!*.'." OK POTENTIAL E'A'lROttttt.'fAI. URALTH HAZARD ASSOCXATCD UlTM AirvTOKi.x liTiuawj. rxcEiiS Dtrnoj dorii.'G xacokive ore r/vOcr.ssuic DRATT RcPOSI . * /; K June 1. 1978 . rhliip 11. Cook>wth.D. ;>--v- EtrVTEOSJEUIAJ, RESEARCH L'JORATOEY-mRAJTK U.s. liivlrcD^=iTitil Prc'it'ctloa A.jacy 6201 Gossan Kmilcvurd Duluch* ilium (:*ots. ' SSi/On V* t *r- ' i *v. I"/. *. r 'f r i ..J C V/ r. t. $ i r i **--. .*.**. -V* * 5 l/.-i :;* J\ r.l* i'umI rrj.vic Itic rirur<t Ptc VflOJU \l> C...u..v.U....C......(.l.U...b..e..S...t..*..;.'-';, ___... - C,r plr.u.d M>il pcvil.u-.it-.a ircr.othellton, .nil .itiiuil irnr.L mnctM in tvm. C.hrymt.ile end this ftr.-ir J.Oo! lie and r.aouite associ* it d vlth *11 thenc dievaacs* Vihrous /n.-pbibolo lcioersl;; relc-osed Iron rock durliignon-asbeatoa tdaiug operations pose n less veH-dvtiuad risk c.f disuse vbcu inhaled. Sincc- little, or no c-piduciolegicil or tnus.J. study Oi'.tii er-lctc vViieh can lit . applied specideally to each occurrence, risk ntr.es&tir.l often depends on corps risou of physical and cbtsaiccl y.-roperties tu r.sbi::.t09 nod on ccsperi'/oa of airborne fiber ccacestrationn to ccuvceutraticus associated t--ith asbestos . dir.tave. . ., . * ** . .r* Excess canter and pneu.-sotoniosis deaths have occurred for vorkchri exposed to Aerosols oi talc conteuiiutted with trcroilte, autbophylllcc, ar^ cliryeotilc (A). A study of underground tiiiiro in a gald cine tcith p.rur.trltc fiber? has dtaoa.Htr.-ited a cbrct-fulu excess of respiratory caster lrortality (5) but a subsequent study (6) of a larger cohort trot: tee sttsta cine (Dot lirdtud to underground workers) indicates 00 excess of respiratory " cancer deaths. . .' . ...... '.Chat bar-is odists for associating asbostos health. hazards vich sciairal ' fibers released by taconite nlaing arid lieccfication? 0cause of their ' unique structure, chrysotile fibers are certain to he identiccl morphc-loglcally structurally, and chemically to various chrysctile fibers relucted by cbryr.otilfc etbestos cinicg and Exiling. Comparison of acpbibolc fibers to I : known Mr-ib-iholc asbestos r-atfctxr.ls is core difiicult because tba vac-iota r-mphibola ttkvjrals are forr.ed vich both fibroist (-jtbestifom.) and. con-fibrous . habltc. It Is clso probable that a gradation "exists between. extremely fihroua ana aon-fibrous Er.pkibole occurrences. h c A further complication is the propensity of azubibulc trir.erein to cleave, or split along preferred crystal plunas, whan crushed and thus produce particle* with length to diam-itcx ratios ic -excess of 3d. Aiiphibalc fibers produced from arphitole stbastos such as rjeosite cay also result froa cleavage, however. Ko biological dec a exists to thou different rc-spoasc to samples of onphibolo fibers which differ only in subtle internal crystal defect structures or in crystal fate orientations although these properties ixey be related to the eubestifore nature of the nintral terple frit tern ''fiber" in this discussioo refers sicply to say free pa.rtide with a length to vidth ratio equal or greater than 3:1- th*! UCC 007440 V <*,, _ A 0/ I1'` A current popular theory. no^np, nsbcst *.*; health experts to tluit nay long* thin durable fiber J ntrndutr.d into tisane will iuluce rnligiwint ncnpl.-iK.u;. l'Li:nt(>i> (7) .!*.>> .Turned 17 fibrous jjlnwwn of different dlj-enuiorml dtstrlliufioita into the lOrur.n: uf rots mid obscrvisl rime fiberr. loss r.h;u ov cr,uul to 1.1/ pc in di*'.r;f:t.c'r and greater than fi pc in length yielded the. highest probability o pleural xnveoiico. Extrapolation of these result** to fiber c;:rclnr>f.er>tBii> in nan is subject to consideration of the intluenco of fiber cHr.vnson on .icrodynaclc bebuvior,-penetrability, wid clearance fron the lung; i.e., r.or.e el the potentially more carcinogenic Ciber sicea rsay love prc-acly diminished abilities Lo reach target tissue. The' g-aoerally accepted greater cancer rich associated with crocidollte liber iuhalatioa ;>c compared to chrysotilc fiber inhalation may result primarily frets greater lung.retention ol croaldolice fibers. .' " % V /ishestor. aerosols invariably have a wide rant;- of fiber lengths and widths. F.ven cnlxsil'experiments cannot provide absolute. eCfect/fiber sire . .. relationships cince asbestos sac-pies of uniforn fib*: sire luiva not be*n prepared. Rats lntrcperitone-ally injected with short cbrysotile fibers leas chan 5 p= in one test and 9ST less tl-.cn 3 pe in a second test) incurred approximately 4C7, incidence in tutors, in a study' (3) uliicb provides the closest association between short fibers and carcinogenesis. PulcatLiry tissues of asbestos vjrlxrc contain necy care sliort fibers tlvan lot>g with an even charter fiber oire distribution in pleural tissue (9)* : r ' ; - ,-*i / - . ... - The Vbwirotentotal Protect ion Agency's an.ir.Al teste of nrphibole fibers i obtained from Reserve Kininp. Coinpany (P11C) will net be completed until 19S0. These tests involve intratracheal, installation and intrapleural injection of W1C ncphibolc fibers and anooite fibers in rats (10). The aephibale fiber cnnplca used ore representative of ibt:rs found in air samples fro;j Silver hay hut not typical of all- ci-.j/hibole fibers present. Tji vitro tests of FKC ntphibolc, arosite, crocTdolite, chry&oclla, arithophyllitc, trcr.volite, and a DOn-fibrous gruneritc indicate that the J'JIC ncphibolvi Id lytic to cheep erytlurocytes and depresses rabbit alveolar macrophage cellular viability sbuilarly to- the onphibole asbestos r.arrplee whereas the non-fibrous gruocrite scmplc is not active. Cytotoxic effect in such in vitro tests has been linked to the ability to cause fibrosis but ic not necessarily associated vlth care loogene sis. ti 15 >5 ir I vk t- rC tl It*. Hineral fibers with structures and surface properties entirely different than the asbestos miner;*Ik con be carcinogenic. Ra.lygnrr.ki to, n fibrous clay mineral* induced a;; many mesotheliomas, Col lowing iutraperitoncul injection in rats, as chrysotllc (11). The extraordinary incidence of rcsothclloms la n Ttirhir-h village (12) is now thought to be a result of ccolits fibers releared into the envirenceat by erosion and use of volcanic tuff (L3). UCC 007441 A O <n* U r\ the rh.;-ical, nul xvirpbological iiiullurity t>i IU!C ni'phibole 1 to n:-.o:.lt.o fibers, it i: l-xist likely thit intis In Lion rspomrc In high rr>:tc<:!ii.r~Lhi:is of these: fibers; would produce nghnstoa Ii j). injortant to note ibnl. nt tills; tire no evidence of tibronlo in rr.ployt eo with V ;ji limn 20 yv.tr:; i-.-splojia.-.nl. ti; found by pyl.i-jjoory function studio:; oml dlv.st rcdlttgrr.phs (14). Than r.tudicr. can not lc extended to corel'uJo rh.-tt iucresm .4 rink of ]un; cancer nod cxsiot.lielicxi* lu absent but indicate xhv.t cvv.ouuvc:; f.u l ibur:-. are considerably lover than thane experienced liy ashei-ios worU.M in the pn>;C rwv\ "nnsjocinted with . nKburtosiu smi curtccr. KC5A "spot dust inspections for rJmsr/il fiber* ' iuJicctc tie* weighted nver;;y:c filter concentrations in HUC working areas*- ate far hc-low the occupational health nUiadards foe asbestos r.txi tven further below the concentrations usbastos workers were exposed to dccaden ; x g` j. i ; j' ; .. t ja-* * A- The corsuiiity air at^hibolu fiber concentration!* in Silver Bay,. Kiiinreota , 1I hove tiov been well cluir.ictc^rieed by tr.ins.iivrion election ritcrojcopa analysis of oir nmoles collected on eembrnae filters. /ecphibole fiber -. concentrations; at throe rites it;'residential Silver Bay were detemiuad ' * >*r; frees continuous air ronitoring coavcrc.qa appror.icately 125,000 fib era per cubic rater for the years 1974, 1975, anil 1976 (15). Tbs electron ri>. microscope analysis was pfirforned with a technique essentially identical to the Ir'A provisional rstbod published iti August- 1377 (16) taa was in excellent agreer-imt vitb. results reported independently for 12 air samples bv the liinavr-ora L)ep;urf.-:;nt of Health and lie. Stoat School of t.'edicino . Hnvironr-ir.toi Scicocev laboratory. Three other laboratories participating I in the iucurl;ibr.ratory comparison each used inferior onelvcis techniqueo I and produced data which failed to correlate with any other laboratories* results (17). Air liiicplee recently collected by Regies V during and after e. prolonged sherdown of Eeserve J.Utiiog Company arc currently being analyzed <u` t; '\ \ .f .t : I V I cud appear to show very low nr-phibolc fiber concent rat to a a in the Silver :i Bay air during tbe shutdown period. Although stock craicsion controls being * i. installed should greatly reduce fiber concentrations, fugitive dust froa tb.e on-lcud tailings basin to begin operation "in 1985 pose, an ualnau-n rv. X addition to scphibole fiber concentrations in the air o the Silver Bay urea. i t The dose response equation for huiSiD inhaled fiber exposure Is not well established find the e;-Jctence of an exposure threshold, bclov ohich iotreastd center risk, is zero, ic unknown, /uspliibolc fiber concentrations t if in the air near the taconttc processing facility at Silver h'ay, ItinnesoLn arc prohsb.ty at least l,rOD tjjcas lover tiunn past cc-ntcncraticaa in the 1 asbestos iiidustry which led to high incidence of asbestos disease. Evaluation of the environmental hazard, heuever, requires consideration of factom suc)> as 24 hour per day exposure, exposure initiation uc infancy, I potentially longer period of accurailaied exposure, and acceptable i envirorireiital health risk versus acceptable occupatico.il health risk. A corpaunding problet; for assessing cancer risk at lower exposure levels Ii ..i in the inamuffed lapse Lire beewe-an initial, closure nod onset of disease (1C) \ UCC 007442 A u MU u C' -- /* The n:nv.tlhtblo r..->n i t or i ng, luaHh, nJ r.lnt-ralogir.sl information t.houJd nut cW-iige UV,'h oxigliviliy i'fated ctmci'tn for the lung-t L-rei health of persona living in rht: v.lcJtiity bf l'icon itc proccar.ing J.iclliclti; vMt:h handle ore )Li;1iJ> c<nit;r.!n:if c-3 with orpMhriJc or chrynotilc fibers. Euiuttlons to the cnvlroao'atC of r.och fiber:. ubjiild ho controlled with heat Available r e-cbnalro-.y. Suih runtruly arc' plinmed ior inscullotSon. ut P.coerve KJLutui; Coru;n:y. It r.hould lci 'listed that, while the 8th Circuit Court decision of hatch 14, 19?ii c.-l: -IV,c best that can he e:id Is that the existence of thin Asbestos . ccnrnwlnMit in air and water gives rice to a reasonable cedical concern for the public health. The public'n exposure to ashtoton fiber*: iu water eud nlr creates neat health rl.sk. Such a coatonirumt r.'iauld be uaiv.'d," ` th.o fittings of fact of the United States District Court ia the Reserve lilixlag iriel were not reversed-or codified bj. the 8th Circuit Court. - These . findings of fact included! '' 1. ` ".Many of these fibers are morphologically and chceiically identical to acosite asbestos and nn evtu larger Durbar are sirl-ler to acouite asbestos." ` - 2. "Exposure to these fiberc can produce esbestosis, mesothelioma, and cancer of the lung, gastrointestinal tract, and larynx." r<> ' ,V g l1i* *l,f-*4y*r . iI:;t; 3. "The discharge into the air nubs tantially endangers the health of the people of Silver J5ay and surrounding coirminities as far Vj-. away us the eastern shore in Vis cor,sin." rI 4. "The present and future industrial standard for a safe level of rishsstos fibers in the air in based on the turpi-tiente rein ted to ntibestosjj: and not to cuucEr. In addition its .5. }>&> formulation was influenced core by toclmnlogical linitatloao than health considerations." s !r tv^ >* 5. "The exposure of a non-worker populacfc cannot be equated with industrial exposure if for no other reason, than the environmental !I exposure, :<c contrestod to a working exposure, is for every hour o every day." if p=- (5 * i 6. "t'nile there is a dose-response relationship associated with the i adverse effects of asbestos exposure find cay be therefore a threshold exposure value below which no increase in cancer would i r be found, this exposure threshold 1g not now known." i UCC 007443 AJl I. 1. Jiilc rn.'<t.) Ai-.i iicy on U'.-urn* rli t.y.ninsC (.i>')'_cr (IAl.C), l!'iiiHjT.,i|.11 on V-v.. Ii:;l >'( r*l t \xv Core in.'n-.cnl c Rink of. Cbi-v. Icnlr. to K'ltt, "(ivv/V?' 2. JU v.)o;ircT 15. I.. mil Thompson, II. KcMiothfclir>r.a f plcutn and - jit:r11mi'.-iii; folltv-inr, tv?>osure to asbestos; in the London area. Frit.. 1_. Imhistt. Hk. ,'22,* 201-209 (1905). ` K I* 3. Andersen, 11. A., liilin, R., D.iva, S. I!., FJschbeln, A. S., nnd v r.r)iL.of, I. J. Thiusebald-contact esbesito* neoplastic risk. . Ann. !K_V\ AcrJ. f.;f. 7.71, 311-323 (1976). Idcinfeld, H., Kessitc, .1., Kooyron, 0., .mil Euki, 1-5. Mar talley ' csotig. talc cdnerc and uillcrn iu 11.Y- state. Arch. Environ. Health, 14, (63-667 (1907). . : .. ' 5, Cillar;, J. D., Det-ent, .1. K., Lttrta, R. A., Uagooer, 1. K. Archer, V, e:. ntvi Riojor, H. ?. Mortality patterns acong hard rock gold irinerc eV.nos'.id to so HsV.2ivtl.oni rii-ixeiral. Ann. U.Y Acad. Snl., 271, 336-3^2. (1976). <<i 6. Kclion.-'.ld, J. C. Presentation at the American TnorAeic Sor.iaty Annual Meeting of June 1977, Abstract in Aacricao Revfeu of HcT.-ilraLcn.-y Dlneesc, 115(A) , 230 (1977). ii 7. Bcr.uton, lb F. , Lnynrd, M., Tegerie, A., Killer, E. , Kay, VI., and # rent, E. Carcinogenicity of fibrous glass: Pleural response in l.ht rat in rejatiun to fiber dimension. J_. Untl. Cancer Inst., i 5B. 5S/-603 (1977}. _ " i 8- Pott, F., Kvth, F, end Friedrichs, K. Tisaoren der retee tus-ch. i.p. injcl.trion von r,e.iVihleD;.' ehryr.otil und bento (a)pyren, 2bl. Bskt. , ,1. Abt. 0r\?;. B., 155, 463-469 (1972). I 9. Rigaan, J., Febastien, P., Caneichac, 7,., and Eororaud, C. llsosureaent of asbestos retention in hutxns related to health effects. U.S. i Bureau of Star.ilariis Kaeting on Asbestos, Gaithersburg, Maryland (1977) .10 Coffin,- R. L. and Pelehnr, L. D. EPA otudy of biological effects of 0Jib;:stt'5-liiX` rJLrtcral fibers. U.S. Bureau of Standards Meeting on i Asbestos, Caithersburg, Maryland (1977). i U. Pott, F., iiolgtier, R., Friedrichs, K., and Uuth, P. . L'efiet oncongune dn; poussiires fibreuses; L'cxperlcention anicale et scs relntious avee la carcinof'inkse hueair.o. Ann. Pathol., 21, 237-246 (1975) fM .r 12 Iicrlj;, X. Pleural Msothclionas ond asbestos pleurisies due to .3 m cm.'lvonn?ritnL acbe.stos exposure in 7ur)xy: an analysis of 120 casc6. 19ir.cn t-r-e bull. Med. Snr;;.. 165-125 (1975). fer V? UCC 007444 . A  i 1G * n. I'i'Mi'V, F. lY.nvl on Current conceptu in fiber pntli>;'culcit y. Csmievcnce i>n ivifil l.t> Fibrous* imj l'urt iculnte )un;t imU 'i'lirir l.i.tinto tJiv r.iivlVtciiX-nt-Foricty lor OcCu)>nc.loii;il laid Divlnument al Health, Var-lilt>j;ton, JKC. (2 977). .ia C,tc.\:V., T. el l*arrlm;Lon, V. Tocavxite duut exposure And reapirotor-y nbuornal it ics. Report to lieiicrve lUnln*; Coitpany (1977). I m4U 15. Cook, P., Smith, t'., rani U'ilson, D. Airphibolc fiber content ration t'.etcrtitont.iuii for n ncrlcs of cots*.unicy air oncples: uuc of e.iffraction to Puppluciot electron rJLcrt'ycopo analysis, Proceedings of 2jyir^:;fioii on Electron Microscopy end X-kay Applications to r.nvj.ro:v=cntnl ftnd Occupational Dcaltli Analysen, Attn Axbor Science Publishers (r,'7S). ' I 16. SneudrA, 7i.t Harwood, C., Stoclhan, J., end Vagran, J. Electron rdcrc-scopa ir.CAsurocr'iat of airborne nsbestos concentrations: a provisional r-.itliodology rionual. MPA 600/2-77-178 (1977). 17. ERT.-D assists StC-te of Minnesota in He serve Mining Cor?any 'o Court Appeal, October* Bucecber Quarterly Report of ERL-D, 5-7 (1575). 18. r.nterliue, P. Pitfalls in cpidcrxiologicel research. J. Occua. l*ei. 1H, 150-156 (1976). I I *> iI UCC 007445 rr. ` .