Document mmY70ZDpxGBa6kp455OkNR40k

L/C V l INTERNAL CORRESPONDENCE Trfdt* -Jjy^ METALS DIVISION To (Name) Division Location Mr. E. A. Piersall UCC - Metals Grand Junction, CO Copy to Messrs. R. G. Beverly G. J. Hanks, Jr. E. W. Kantz J. L. Mye rs File (w/e) ii* * ii P. 0. BOX 579-4G25 ROYAL AVE., NIAGARA FALLS, NEW YORK 14302 ,c oriBinaimg Dept. October 31, 1978 "Calidria" Asbestos Answering letter date Subject Regulation of Taconite Tailings as Asbestos Attached, for your information, is more on the EPA actions to regulate all mineral fibers as though they were asbestos. So far we have been able to convince their RECRA people that asbestos is already heavily regulated under NESHAPS and should not be also placed under RECRA. There are problems, however, in that asbestos is on the "priority list" that came out of the EPF/EPA court settlement and it is conspicuous by its absence. Best regards, 7 Harrison B. Rhodes HBR/rmm Attachment *J/M letter 10/9/78 only UCC 007435 A-U/u4 t Johns-Manville Sales Corporation Ken-Caryt Ranch Denver, Colorado 80217 (303)979-1000 October 9, 1978 Mr. Joseph Padgett, Director Strategies and Air Standards Division U.S., Environmental Protection Agency Research Triangle Park, NC 27711 V. s . 1 Dear Mr. Padgett: EPA's Carcinogen Assessment Group recently sent us a copy of Philip Cook's June 1, 1978 "DRAFT REPORT - ASSESSMENT OF POTENTIAL ENVIRONMENTAL HEALTH HAZARD ASSOCIATED WITH AIR- BORNE MINERAL FIBERS EMITTED DURING TACONITE ORE PROCESSING." In addition, we received a copy of Roy Albert's June 28, 1978 memorandum to you, setting forth his recommendation that EPA should regulate taconite as an asbestos cancer hazard. A copy of. Johns-Manville1s comments on Dr. Cook's draft report and Roy Albert's recommendation is attached for your careful consideration. We are distressed that Roy Albert, as Chairman of EPA's Carcinogen Assessment Group, would use Dr. Cook's draft report as a basis for recommending that taconite be regulated as an asbestos-cancer hazard. Not only does Dr. Cook's report present a superficial and incomplete assessment of the present state of knowledge, the assessment also contains various inaccuracies which we have noted in our comments. . In addition, we question the propriety of relying on any health hazard assessment prepared by one v/ho is trained as a physica'l inorganic chemist, rather than by one with ap propriate scientific credentials. Furthermore, we disagree with Roy Albert's conclusions re garding the potential health effects of short fibers. There is both human and animal evidence to show that short fiber lengths of asbestos are not fibrogenic or carcinogenic. This evidence is not "suggestive" or "indecisive" as characterized by Roy Albert. Our attached comments refer to the various animal studies which clearly demonstrate that these short fibers are biologically inactive. In addition, McDonald's study of the Homestake Mine found no excess of bronchogenic cancer, or any other tumor, in this population exposed to short fibers. As indicated in our comments, althoufcfy j UCC 007436 Mr. Joseph Padgett October 9, 1978 Page 2 NIOSH study did report an excess of bronchogenic cancer in a smaller cohort of this population, that study is so plagued with scientific inaccuracies that it is being repeated. It is our hope that EPA would undertake a more complete and objective assessment of the potential environmental health hazards associated with airborne mineral fibers emitted during taconite ore processing before making any decision with respect to the possibility of regulation. It is our understanding that short fibers of the cummingtonIte-grunerite series of minerals are commonplace in the general mining industry. Their presence in taconite ore is not unique. Therefore, if EPA were to accept Roy Albert's recommendation on its face, much of the mining industry would needlessly be regulated as posing an asbestos-cancer hazard. We would be glad to discuss any questions which you may have regarding the enclosed comments. - Very truly yours Richard P. Carter, Manager Government Affairs Health, Safety & Environment Department Enc. RPC/lc cc: S. Gage S. Jellinek W. Barber M. James R. Carton R. Albert D. Goodwin bcc : P. Kotin, M.D. J. Autry J. P. Leineweber D. Poutiatine B. J. Pigg> UCC 007437 /L U / 'J ) JUN'5 ii^78 FROM: TO Roy E.` Albert, `lalrmai Carcin... o_g___e__n ___ Assessment ______,, * , . , * * ( Joseph Padgett, Director . Strategies and. Air Standards Division 4 This is in response"to your memorandum of May 3, 1978 requesting CAG assistance in determining >dither EPA should ... ' )] regulate taconito as an asbestos cancer hazard. .In our ' oTvirTion the answer should be in the 3*>'iTr3tivo. The attached report by Dr. CooJc susr.arlzes the present state of knowledge. In essence, there is suggestive evidence that short_fiher lengths of asbestos may jot-- k tibrogenic or~~carcino genic sq_- ' far as mesothelioma is concerned but the evidenco is not ' 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 clul Coo -iiuthr' K cc: S. Gage S. Jellinek IT. Barber V M. James R. Carton E. Anderson CRU/2 copies CAG Reading . r~'./v;'_v:" EAnderson/dj/6/27/78 UCC 007438 t4 * \ r- ; ASSESSHB.T QY POTENTIAL EUVIftOttiurfAI. UPJkLTTi HAZAlS ASSOCIATED WITH airrorke mmv-vL fic*ers putted DURING SACOXITE ORE rRDCF.SSIEG ' ; : fi&AZT REP02X '. "1; - J T June 1, 1978 ' "V ' ; - ThlUp H.-CooV.^I-b.D, V Ea;vn>o:-^iZ';T/a. research latoeatcry-mrcuTH U..S. Envlrcja-s-it^l rroti-ctiua Agency . 6201 Coa&dan Koulevturd * Dul^cti* HiuTUiioLi. 5 5 DO* ' i'L- r- ' r.'. .v^Vi^v 4' `:`>~ .r 'i ;.!: I2L -if * f Mi . ,,Y C,, T ' li >* r . l: 4VWife .[ &T ' S T-'"; V. ,-i ' < - 'j. ,**. '<`-i ^',| v'iV " "-T ' 1 a ^mSi; ,/ r V.i - v YXrV'Vsr* SgAi - * - i* . " ' *4.r ,* ' .. UCC 007439 ?\ *' .a: o? (-S .- %>>v-" T-". iv: v.` ) .`'h:*. ;;* j i\ r. ti icn-iv.; duul **vrlv<d from. r InLog, i.-tl ling, -"ind ii>;u of nubuutori five V.neun Vo Cwui.e lv:ig r.-ntf-i. r, plain ul m*i1 pevituiirtil i^-:sol hi: l;ui.l jw'viCVi.ii.U.r.tiiUil irne.t r mi ter in twin. (hrynnt.Ui* and the nr-phibolv.': crfir idolLtc and r.s'juitci-;u*i; /issucl*itd vith /ill l.heue dluvuiitis uMlr inuhnpbyl 1 ltc ndncd in 1'iwYitnd is ovuicSci < d with nil execi.i; limp, tricar rifO. /nil high dt-nrc of pi ciu:/;! thiehC'iiing nni t'^lcliicitcion (I). K.-ni-i>rcup:;f jon :l >: to aribuy I o'. J.u C11-: neifhV.oiioud:; of inioatrial itourcc:: (2) or from Iioiimlrld contact: with nshustui; workers (3) leads to inet cased risk for ncsnthelSosa. Fibrous nuphibolc niaatnls released frera rock during.'no-.i-ar.beatas tining . operation.'.; p;>;'.e a iiu;!; veil-defined risk of disease wheel inhaled. Since.- - little, or no epideciolcigical or anL-a.-t study data eristc which can bt Applied specifically to each oecurrrncii,. risk nsr.es&rar.L of ton c'.cpf-.nds on . cnepnrisou of physical and eViuaiccl yi'oytrtic-'j tu r-Chaatos and on ccrporiuou.. of airborne fiber concentrations to nonccntraticus associated with asbestos . . disease. . 1 - - -.; j:>i.. . i; ' ` *- * ' .` ' Execs? cancer and pneumoconiosis dn.-iths have occurred for .vorVxiiTi exposed to aerosols of talc contauluatcd with trer-elite, antbophyllite, arid ' . chrycotilc (4). A study of underground triears in a gold cine Kith p.runtritc fibers: has d e on n;> crated a tluce-fold exerts of respiratory cancer ' mortality (5) but a subs*:Quest Gtudy (6) of a larger cohort iron tea seta mine (not limited to underground workers) indicates no excess of respiratory cancer deaths. . . ; - . .. ' ' , . , ' '' - V'hat bar-is er-rists for associating asbastaa health liaxards with vrineral fibers released by toco nice Mning avid benefication? E-c-cnusc of their *' unique structure, chrysotile fibers are certain to be identical morphologically structurally, and checically to various ekrysetile flbsrc released by chrysotile asbestos ci.nin.3 and Eilllog. Corcparlson of arpbibslc fibers to . . known acph.il'olc asbestos rattrials is core difficult because tka various ' , r.rphibola islTi-irals nre furred with both, ribrojjd (.-jsbastifom.) end nan-fibrous . habitu. It is also probable that a gradation "exists batween. exfreraly filitoua and nan-fibrous ar.pbd.bole occurrences. ' . , f- ** ' ** . A further complication is the propensity of onuhibolc ciraraus to cleave, or split along preferred crystal planes, vbin crusVed and thus'produce j^articlcs with length to dioneter ratios in execus of jil. /uiphibalc .' fibsrs produced froa arphibole acbestos such as tcasite cay also result , froa cleavage, however. I.o biological data exists lo thee different response to r.rer.ples o cu-.phibnle fibers which differ only in subtle internal crystal defect structures or in crystal face orientations al.tbougli these properties may be rciocui to the esbestifote nature of the tintral sarple R Ine tern "fiber" in this discussion refers sicply to any free particle vith a length to width ratio equal or greater than 3:1. .- I UCC 007440 i f*, AcU/ V\ I l!` A current popular theory ricong .`Uibtmto:: health experts is ttuit any long* thin iHif.iltJo fiber iMtroc'.u:r.d .into tissue uiLl i'4uce naligritmL nenpl.istju;. i'Lcnuin (7) .lijji.lum(:t! 17 fibrous j;lmt:<!. of different dSr-.L'tmionnl di'-tributiemu into the of rot:* and obuervcd that f,U.i:tr. less than or er,ur..l to l.i> pi: j.n ilkciUcr and greater tluin ft i*ts in lunyt.li yielded the highest probability of pleural Narcor-ao, Extrapolation of these rcsultu to fiber c::rcin:>p.cni*aiu in nan is subject to consideration of the influence of fiber cHivL'nsmi on .levodynnc ic bohuvior,- penetrability, wk! clcctanc*: froat the lung; i.c., .r.oriss of the potentially tore carcinogenic fiber siren ray ` have pronely rllniniched abilities lo teach target tisane. The' {jenarally. ' Uu- S? ' . !-:? Accepted greater cancer risk associated with crocidolite fiber inhalation . an compared to chrya-oti] c Fiber inhalation tiay result primarily fros greater lung .retention of crocidolite fibers. .! . . a- Asbestos aerosols invariably have a vide range of fiber lengths and widths. liven salmi experivrants can not provide absolute <;tect/fiber f.lce . .. relationships oince asbestos sar-pleo of unifora fiber nize hava not "fc:a - prepared. Eats intrapfcri.ccmea.13y injected with short cb.ryaotile fibers " (911 less than 5 ps in one test and 0S7. loss than 3 pe in a second. test) incurred apprnxicatcly a A07. incidence in tumors, in n study" (S) uliich provides tbe closest association between short fibers and carcinogenesis. Puliaou-iry tissues of asbestos vorkerG contain cany more rliort fibers ` tluui long with an even shorter fiber Glee distribution in pleural tissue (9). t.w . ... :h^s . 11 I< The Knvirountotal Protection Agency's ajoirAl teste of naphibole fibers > obtained iron He nerve Kining Corpeny (PJ-.'C) uiLl net ha eor.pleted until ' 190. These tests involve intratracheal installation and intrapleural . injection of Vi'.C nmphiholc fibers and aiooflite fibers in rats (10). The ' ; ' acphibole fiber camples used ore representative of fibers found In cir hcopies from Silver hay hot not typical of all- arpbibole fibers present. 1 In vitro tests of RKC acpliibole* aronite, crotidoiite, chrycotil-a* anthophyllitc r trenolite, and'a non-fibrous grunerite iudicate that the WiC nrphibole Is lytic to sheep erythrocytes and depresses rabbit * alveolar mcrophnge cellular viability similarly to- die. aaphib-ole asbestos r.ojrpleo whereas the aon-*fibrous grur.crite satrple is not uctivn. Cytotoxic effect in such in vitro tests hoc been liulied to the ability to cause fibrosis but ic not necessarily associated vlth carcinogenesis. . ... . i. b % r tt Li- ! i Kineral fibers vith structures and surface properties entirely different than the asbestos raincrali; can be carcinogenic. Palygorr.kite, n fibrous clay ciueral, induced as many ccsotbL-lior:nB> following intraperitonenl injection in rats, t:s chrysotvle (11). The ey.traoi'dinary iiicidence of necothclio^a in n Turhich \'illage (12) is nov thought to be a result of rcolito fiber3 rclc-ared into the environment by erosion and use of volcanic tuff- (Ut). UCC 007441 A o<_ n<-> uu :"S hJvr.-ii Hit cl..;'ical, c rynt.o) lopiraiibi c, /nil i.vir pholog. Leal niuiluricy ot l'JJC nrphbbole to fiber.',, .It i<: i-ost likely tint inhalation Dpoxure to high concern.i`"Ums of tV-'Mto fiber!: would produce nshnstoa *(ir.t-:>f.v. It J>. injijt I ;:nt to nolo i.hnt. at this tire no evidence of fibrosis in i:il" or-ploycer- with V ;n e t.h::n MO yours ivqilo.w.'.'.nf. li; found by puliunury function studies and chest radiographs (14). Ibne studier. can not bo extended to conclude Mi lt iucreast d rink of fun;' cancel' and cn.'inf.lu.'lioiaa Lu absent but .`Indicate tint. ci'.ji;>suvc!; to fiburn me considerably loner than tbar-r. experienced by nsh<",,-toy workers in thy past mvl `nnsocinced with axbto:;La imd cancer. Kf.r,A':rpot dust inspections fur mineral fibetH indicate tic* weighted uveraitii fiber concentrations in HKC working areas'' are far below the omijmr.Ional health rtiiulurdi; for asbestos r.ui even further below the content rat ions asbestos workers were exposed to dccadeG nj;o. . ' r *k ' ` Tlit cercrJiiity air airphibolu fiber concentration!! in Silver Bay, Kliuicaota hove mm been well cluirnc tciriv.ed by trunsriiusion electron tcicroscopa V analysis of air samples (:'j Lice, ted on cambrnae filters, /ccphlbole fibex concentration.'.; at thrti cir.cs it: residential Silver Bay were dtterrdivad 1* froze continuous air laonitorin;* to average approximately 125,GUO fibers, per cubic rater for the years 1974, 197b, aivl 197G (19). Tim electron, microscope coalyais vhi pfirf creed with e. technique essentially identical . to the EPA provisional r'-ethod published in August 1377 (16) end was in - excellent ;'.p,ro*rr^int vith. results reported independently for 12 air snrplea ..** by the llinnesoru bepartreat of Health and l!t. Sinai School of ldodlcine .. I Env.ironr-ir.tai Sciencev T-shoratcry. Three other laboratories participating I . in the iuterlnioratory comparison. each used inferior analysis tecbalguca l and produced data which failed to correlate with any other laboratories* J results (17). Air -uacples recently collected by Region V dutf-ng and after a prolonged shutdown of Ho serve Mining Corzpany are currently being analyzed ` cud appear to show very low ozophibolc fiber concentrations in. the Silver Lay air during the DhuLdoun period. Although stack emission controls: being installed should greatly reduce fiber concentration.*;, fugitive Gust froa . the on-lcud tailings basin to begin operation "in 1983 pose an iroJajD'.ia * addition to strphibole fiber concentrations in the air of the Silver Bay urea. , Kr. 1 -f t The dose response equation for human inhaled fiber exposure is not well -established end the existence of an exposure threshold, below which increased cancer risk is zero, i.G unknown, Auzphibolc fiber concentrations in the air near the tacontr.c processing facility at Silver Lay, llirmesota \f * 9/<^ '\ arc probably at least 1,0jD tines lover than pant concentration*! in the asbestos Industry which led to high incidence of asbestos disease. i Evaluation of the environmental hazard, however, requires consideration of factors Guch as 24 hour per day exposure, exposure initiation at infancy, ! potentially longer period of accumulated exposure, and acceptable i. env; rorir-ental health rixh versus v.ccejrr.able occupational health rial:. I ' A compounding probloc for assessing caj\ccr risk at lover exposure levels Ii ..r is the increased lapse Lire between initial, exposure and onset of disease (lb) i UCC 007442 rr* t . A ud t .* h The rev avallabio t or lug, Ik Tilth, and r.iner.ll ogical inf orcation should !I not change LI'A'.'i ovij' I ivil.iv rioted conn-in for the long-tens health of peruana Jiving 'u tin; vicinity M Ibconltc pruccnr.ing i ncillt let; which handle ore highly c<nt;ir.i.nnrr"J with wi-phlbnlc or chrynotilc fibers,. Euimtions to the ciiv Irioi.-iHC of r.nili fibers should ha controlled with best available technology, Such r untruly orr planned lor instill let Ion, at Reserve. , rit* ;v Jliiilu.c, Corpnwy. It should bu noted that, while the 8th Circuit Court decision of Ihrdi 14, 19?li ot.-it cd: "The hast that can he i;i;id is chat the existence of this nubestos . * '** t\fi. ir3* I ccnt,ii.:i.n;;r,t in air and water gives rice to a ve&.uortahlc radical concern fur the public health. The publicexposure to fiibfcato.a . A. < ,a fiber;; in water end sir creates liose health risk.. Such a coataninsut U should be rcrov^d," ' the fii-dings- of fact of the United States District Court in the Reserve ' m ir" . l..- ' IX - Killing Trial ware not reversed-or todified by the 8th Circuit Court.' These finlinga of fact included: - ' ' ` i'* 1. ` "?5.iriy of those fibers are morphologically and chemically ., identical to aconite .asbestos and an even larger nuebtr are siciAar to acoaite asbestos." .y ' I; k I 2. "Exposure to these fiberG can produce asbestosis, nesotheliora, .k m -V. 1 and cancer of the lung, gcatrointectinal tract, and lory-mi." - ."ST; i If? IS 1. -- 3. ""be discharge into the air substantially endangers the health s of the people of Silver Bay and surrounding couroinities as far avny as the eastern chore in Visconsin." ,_ .. 4. "The present cod future industrial standard for a safe level of fich-sstos fibers in the air is based on the experience related to nebostosic and not to caucEr. In addition its r: & F>> t* i forr:elation v.is influenced care by toclinnlogical limitations than health considerations." s fef : ,v ;** - 5. "The exposure of a non-worker populace cannot be equated, vith industrial exposure if for no oLher reason, than the eaviroacintal Ii exymsure, as contrasted to a working exposure, is for every \ ' !r/ hour of every day." . ` (i? 6. "i-hile there in a dose-response relationship associated with the adverse effects of asbestos exposure and cay bs therefore a threshold exposure value below which no increase in cancer would be found, this exposure threshold is not now known." . it H' ( lI Vf w? UCC 007443 * <': A t ** f I* .c Kofcremri* 1. Jtilfrii.'it.At'i'.'tl Agency oil Kt-munch Against Ciiuaer (IAV.C), JLl'r**LlLlli, on Fv.. I iI ion ni `(he Cure. i 11: i J P- n) (: lUv-h of Chou leftlr. to l'.nn. Auiicbi.iw, Va o:'-A:s"(iyV 7)?"* ............... .2 )Uu]oiif.fi, II. I.. r.nJ Thorp:, on, 11. Hecolhellor-i of pleutn ami . per 11 (iii'.Mit.T foil living l>?>or.ure- t asbestos in the London area. Hr it. . IntUo-j-r. KuA, 261-204 (1905). ^ -' 3. Anderson, II. A., Li liu, R., Il:iua, S, 11., Fischbein, A. S., nnd , ficliLoff, I. J. TUiuseholu-eontacL asbestos neoplastic risk. . `*` Ann. JbV.'iwJ. Scl.. 7-71. 311-323 (1976). 4. Klelnfold, H., Her.site, J., Kooymn, 0.. arid Zulu, M. Mortality" ' toong. t;clc cinurc nu<l nlllcrs lu K.Y. state. Arch. Environ. Health. 14, (.63-067 (1907). . : ' 5. Cill.-t:, J. D., Decent, .T. K., Loren, R. A., Wagoner, J, K. Archer. V. ana Klftjer, H. V. Mortality patterns ocong hard rack gold rrinere expos wl to no asbatstiforc riiueral. Am. K,Y Acad. Scl., 2711 ' 336-344 (1976). ' 6 . McDonald, J. C. Presentation at the Acer icon Tnoracic Sor.iety Annual Meeting of June 1977, Abstract in Arcirican Review of Respiratory Ptr.ease. 115 (A). 230 (1977). - 7. Struton, K. F. , Lnynrd, M., Tegcris, A.. Hiller, E,, Hay, Vt., and ' Feat, E. Carcinogenicity or fibrous glass: IJleurnl response in the rat in re.'J&tioa to fiber dimension. Jk Katl. Cancer Inst.. 5B, 537-603 (1977). " - _ ' .6 Pott, F., Huth, F., end Friedrichs, K. Tuaoren der rette nach i.p. injektion von gccthlentia chrysotil und bento(a)pyren, 2bl. br.Ut. by;1.., I_. Abt. Ori;;. D_-, 155, 463-469 (1972). 9. Eignon, J., Sebastian, F., Gaudichet, A,., and Eoruiaud, C. Keasurcaent of asbestos retention in hutans related to health effects. U.S. bureau of Standards Keating on /asbestos, Gaithersburg, Maryland (1977) 10. Coffin,- I). 1. and Paleh/tr, 1. D. EPA ctudy of biological effects of arbesteB-liiUi nincral fibers. IMS. bureau of Standards Meeting on Asbestos, Calthersburg, Maryland (1977). 11. Pott, F. , Lolgner, II., Friedrichs, K., and liuth, F. . L'efiet oncongune ' dei; poussieres fibreuses: L*expericention aninele et ses relations avec la carcinogen4sc hutaine. Ann. An at. Pathol., 21, 237-246 (1976) 12. beriu, I. Pleural r-esochclionns and asbestos pleurisies due to : cnvivonn?rital acbcstos exposure in Turkey: an analysis of 120 cases. Kficcu-epfc bull. Hod. Snrg., _0, 163-185 (1975). * # u fe-. vsitJL K...-T UCC 007444 . A205r f-'F 'vs PoMey, I'. Pant). tl ji:ca-:i.lo)i i'll curruov concept u in fiber I'ntU.'p.culcit y. on ien-il V.^pnmires t.u Vihrous imd l'urt iciilnLc Hunt mul Their Ki. I mV* i.fti into tlr. r.nvivonrjChC-rrjr icty for CJccnj'ntioinil end r.iiviivmncn( al Health, l.'anitlop,ton, 1J.C. (19/7). 1A, c,\sxV^. [ * liMCcin^Loti^ V. Taeauit/i dust cirpoaure And respiratory nbnarnalities. Report.to Reserve lUnlnp, Coripany (1977). 15. . Conk, P., Sriith, P., end Vilson, P. Airphibolc fiber concentration datcrritnnf.iui' for o net Leu of coecunicy uir oon^lou: uac of -r<y.* <Sif fraction to (.uppleciut electron rdLeroyeopc cna.lysiy., Proceedings o Syi:-p:;f.'iuii on Electron Microscopy and X-kay Applications to . ' P-nviranxc-nCol And Occupational Dcaltli Analyses. Ann Arbor Science Publishers (1976), ,. . '- ' 16. Rnrud'-A, A., Harwood, C-, Stocklian, J., and Vagran, J, Electron .. rd ere-sc.ope ir-aasurccr'int ol airborne asbestos concentrations: a * provisional methodology manual. El'A COO/2-77--178 (1977). ' 17. ERT.-D assistr. State of Minnesota in tie serve Hin inf; Company's Court Appeal, October-December Quarterly Report of ERL-D, 5-7 (1S7G). IS. Rvitcrliue, P. Pitfalla in epidemiological research. J_. Occuo. He3., 1, 150-.156 (1976). .- . #5/ } > UCC 007445 ' /* ' 5tX r A* r? m __1,.. ,/*, A C'tTTj r v ^/r. i in/;v/H COMMENTS BY JOIINS-MANVILLli CORPORATION UN THE JUNE 1, 1978 "DRAFT REPORT - ASSESSMENT OF POTENTIAL ENVIRONMENTAL HEALTH HAZARD ASSOCIATED WITH AIRBORNE MINERAL FIBERS EMITTED DURING TACONITS ORE PROCESSING11 BY PHILIP M. COOK, Ph.D. ' Initially, the title of the draft report leads the reader to believe that the report will provide an assessment of the potential environmental health hazards associated with airborne mineral fibers emitted during taconite ore processing. However, .the report is no more than a collection of references from which the implication is made that there may be a health hazard as sociated with such emissions. In addition, it is incongruous why an individual with Dr. Cook's background was chosen to prepare a document of this nature. Dr. Cook's training as a physical in organic chemist in no way prepares or qualifies him to evaluate potential health hazards that might be present. Furthermore, it is likely that Dr. Cook is not without bias in his assessment of this situation, since he was the principal technical advisor to the federal government during portions of the Reserve Mining trial in 1973- This incidentally took place only one year after Dr. Cook received his doctorate from the University of Wisconsin. Set forth below are comments relating to specific paragraphs of Dr. Cook's draft report. ~ . Page 1, paragraph 1. In essence, this paragraph is an allencompassing statement which implies that any type or level of exposure to asbestos fibers can lead to an increased risk of disease. Dr. Cook makes no attempt whatsoever to place the various types of exposure, i.e. occupational, para-occupational, and non-occupational in proper perspective as far as exposure levels and potential and actual risk of disease are concerned. Manifestation's of asbestos-related diseases have not been associated with low level exposures to asbestos fibers, as is implied by Dr. Cook. The occurrence of asbestos-related diseases is dose related in terms of fiber levels and years of exposure. There is increasing evidence to indicate that even in para-occu pational situations, those who have developed asbestos diseases did receive high doses to fibers. The first paragraph erroneously implies that household exposures to asbestos have been minimal in the dose-relationship concept. It is likely that these exposures were substantial. As recognized by Selikoff and others, the impregnation of drapes, rugs, furniture, etc. with asbestos fibers and the constant resuspension of fibers in the respirable range ' creates an exaggerated hazard. These household exposures provide an opportunity for repetitively high, short peak exposures due to the shaking out of work clothes. Lacking specific dust counts UCC 007446 A 2 0 8 Cn over the appropriate time period, any conclusion that these exposures were minimal is totally unacceptable. Once asbestos is carried home by the workmen, it accumulates in the home; and its presence in the home is likely to become permanent. For example, it gets into the rugs, from which it becomes resuspended by movements such as brushing and walking. In consequence, family members are getting a 2iJ-hour a day, 7-day a week exposure, relatively speaking, rather than an interval exposure. Further more, in the home environment, "an exaggerated opportunity is present for co-factors to be operating, such as smoking and other household pulmonary insults. At the New York Academy of Sciences June 1978 Science Week Con ference, E. Cuyler Hammond, reported on a study which he conducted with Dr. Selikoff and others which was aimed at finding out if . exposure to small amounts of asbestos will lead to any long-term harmful effects. This study traced the fates of 5*550 men who lived in the community near an asbestos plant in Paterson, New Jersey between 19^2 and 195^. The researchers stated that it was safe to assume that people living in that community were exposed to asbestos. Samples of settled dust collected from the attics of houses near the factory still contained appreciable numbers of amosite asbestos fibers. However, the researchers failed to find any unusual incidence, of cancer among these asbestos-exposed people. This is evidence that a low-level exposure to asbestos has not led to any increased incidence of malignancies. Page 1, paragraph 2. The unqualified statements in paragraph 1 are followed in the second paragraph by a greatly over-simplified statement on risk assessment by Dr. Cook, which in contrast .in cludes a statement which implies that fiber concentrations are important in relationship to the risk of disease. As Dr. Cook has noted, the physical, chemical, and morphological properties of fibers are extremely important in comparing incidence of disease from one location to another. However, it is extremely important that other factors, which may have influenced the occurrence of disease, also be taken into account. An example of this is the relatively large difference in the Incidence of disease which is found in miners and millers of asbestos fiber, as compared with insulation workers, which indicates that co factors may play an Important part. . Page I, paragraph 3- We are at a loss to appreciate the relevance of the reference in the third paragraph to the study by Kleinfeld, et al, on exposures to asbestos in the talc mining and milling industry. These were not exposures to short "asbestos-like" fibers of the type encountered in taconite operations, but repre sented exposures to fibers of the type which have been shown in other situations to be capable of producing disease when present in high enough concentrations. While it is agreed that occu pational exposures to tremolite and anthophylite of sufficient dose and duration can produce asbestos disease, we do not see how this is relevant for inclusion in an assessment of the potential environmental health hazards associated with airborne mineral fibers emitted during taconite ore processing. A208r') -' UCC 007447 3 Reference is then made to two studies of the Homestake miners who have been exposed to cummingtonite-grunerite fibers of relatively short dimensions. The first paper reports the research efforts of Drs. Gillam, Dement, Lemen, Wagoner, and their associates at NIOSH. The authors of this study reported an excess of both lung cancer and pneumo coniosis in this population. They attributed the excess to the presence of a form of asbestos in cummingtonite-grunerite ore. The NIOSH group totally dismissed the possibility that this excess was caused by other potential lung cancer hazards present in the mine, such as diesel exhaust, arsenic and radon daughters. Cigarette smoking habits were ignored. The increase in fibrosis was erroneously attributed to asbestos, rather than to free crystalline silica, known to be present in"the mine in substantial quantities. The Gillam, et al paper is fatally flawed due to its failure to understand the problems inherent in studying a small cohort. The authors' claim of excessive rates in the asbestos-related malignant and non-malignant disease categories is clearly based on poor and incomplete data analyses. Even if the claim were based on valid analyses, data to incriminate asbestos, rather than one or a com bination of other coexisting materials in the causation of cancer, are entirely lacking. To ascribe the excess of non-malignant respiratory disease to asbestos and ignore the known exposure to high levels of free crystalline silica in the past, confirmed by the frequent diagnosis of silicosis on the death certificates, borders on irresponsibility. To ignor-e the potential for carcino genic and co-carcinogenic effects resulting from the mixed exposure to silica dust, arsenic fumes and particles, blasting powder fumes and radon daughters, and to arbitrarily ascribe all of their excess of cancer to asbestos particles is manifestly irresponsible and has no justification in the methodology of science. As a result of the serious concerns raised by Johns-Manville and others regarding the NIOSH methodology and conclusions, this study is currently being repeated by NIOSH. . * As Dr. Cook properly notes, a subsequent study by McDonald of a much larger cohort from the same mine indicates no excess of respiratory cancer deaths.. The McDonald study has greater scientific credibility due to its inclusion of a much larger population sample. Finally, it should be noted that neither NIOSH or the McDonald study found any excess of mesothelioma or gastrointestinal tumors. Since the McDonald study did not find any excess incidence of bronchogenic cancer, mesothelioma, or gastrointestinal tumors, and since the Homestake Mine environment included fibers virtually all of which were less than 5 micrometers In length, one can con clude that long-term exposure to amphibole fibers with such physical dimensions, at least at the dose levels reported, does not induce the development of asbestos-related disease. , A208G7 UCC 007448 Page 1, paragraphs 4 and 5- In these two paragraphs, Dr. Cook . Implies that It .is extremely difficult to extrapolate from the known biological activity of chrysotl ,lc and various amphlbolc fibers to minerals which may be similar but not identical in crystalline form or chemical composition. While this may be true, based on the work of Dr. Stanton and others, it is the physical dimensions of the fiber, that is of primary importance, whereas subtle differences in chemistry and physics are of secondary importance. Page 2, paragraph 1, In the first paragraph of the second page. Dr. Cook refers to the work of Dr. Stanton and characterizes his `findings by stating that "fibers less than or equal to 1.5 /< in diameter and greater than 8 in length yielded the highest probability of pleural sarcomas." Dr. Cook has characterized ' * Dr. Stanton's findings in a rather incomplete manner, as Dr. Cook's characterization leaves one with-the impression that fibers less than 8 micrometers in length can yield tumors in these animal studies. However, such a characterization is not supported by the. findings of Dr. Stanton and others. For example, Stanton's fibrous glass studies show a high correla tion between the probability of tumor production and the size of fibers; the probability rising as the numbers of fibers thinner than 1.5 microns and longer than 8.0 microns is increased. Stanton's data show that the low tumor yield group and especially the zero yield group were treated with glass fibers that were either virtually 100$ less than 8 microns in length or were thicker than 1.5 microns. In reporting the res_ults of his studies, Stanton stated: -- "The results of these experiments raised at least two points that merit discussion, the relationship of fiber dimension to mechanisms of carcinogenesis and the relevance of findings to human exposure. An earlier paper proposed that the fibers at the lower range of optical visibility (i.e. diameters that were exceptionally short (i.e. lengths<5/*) might account for the carcinogenicity of several types of glass and asbestos fibers (1). This hypothesis was not supported by subsequent data (2_), which along with that of the present report indicates that the fine diametered fibers that are very long, are carcinogenic and probably become more carcinogenic as their length increases. The negligible carcinogenicity of short fibers is perhaps related to the histological observation that virtually all coarse and fine diametered fibers with ' lengths of 8x^or less are efficiently entrapped by phagocytes. Many of the smallest particles are transported to regional lymph nodes, but even those that are not seem completely sequestered within the cytoplasmic limits of macrophages and _ foreign-body giant cells at th- site of implantation. Similar observations have been made with chrysotile fibers in vitro (8_) . A 2 08 0 6 '"Stanton, M. F. , Laynard, M. , Miller, M. , May, M. , West, E. : Ca'rcino genicity of Fibrous Glass: Pleural Response in the Rat in Relation to Fiber Dimension: J.__Hat'l. Cancer Inst., 58:587-603 (1977). UCC 007449 - 'J - Using fibrous glass samples of unusual -specjficity placed directly into the pleura of hamsters, Smith has obtained information quite similar to that reported by Stanton. Smith confirms Stanton's findings as to the strong relationship between length of the fibers and tumor development. However, Smith found no tumors with a sample in which 98 of the fibers were 10 microns or less in . length. ` Animal studies by Pott, Wagner, Davis and others have also reported the induction of mesothelioma following the introduction of long, thin, durable fibers of various kinds into the pleura or peritoneal cavities. All of these researchers have induced tumors in animals by this method using a variety of durable fibers such as asbestos, fibrous glass, ceramic fibers, aluminum whiskers, and other materials, whenever sufficient numbers of long, very thin fibers were introduce:d. All of these researchers have been unable to induce tumors when only short and/or thick fibers are introduced. In the middle of the first paragraph. Dr. Cook implies that long fibers, which have carcinogenic potential, have greatly diminished abilities to reach target tissue. This inference by Dr. Cook is contrary to findings of long fibers in both animals and man in all areas of the lung following inhalation exposures to-long fibers. ' On the other hand, short fibers are quickly removed from the lung by the mucociliary and macrophage system. The only case where Dr. Cook's inference could be true is in the case of long chrysotile fibers which are curly and present a larger cross-section. This, larger cross-section causes the fibers to be trapped in the bronchial system, rather than permitting them to penetrate to the distal portions of the lung. Page 2, paragraph 2. In this paragraph, Dr. Cook continues with his short fiber hypothesis. With regard to the study by Pott, Hugh and Friedrichs referred to by Dr. Cook, it has now been established that the sample used in that experiment contained a sufficient quantity of long fibers (greater than 10 micrometers in length) to induce mesothelioma. This, together with the massive doses of fibers which were used, can easily account for the tumors which were found in the animals. The reference to the work of Bignon, presented at the National Bureau of Standards in 1977, is another example of the presence of short fibers in the target tissue, with the unfounded presumption that they were responsible for the disease. This is extremely poor logic, in that the mere presence of an agent does not necessarily mean that it was responsible for biological changes. Again, the significance of the presence of long fiber in the pleural tissue of these workers is neglected by Dr. Cook. Page 2, paragraph 3- In the third paragraph. Dr. Cook refers to the work now being carried out by Dr. Pelekar using amphibole fibers obtained from the Reserve Mining Company. First of all, the fact that these fibers cause hemolosis of sheep erythrocytes UCC 007450 A208C.3 0 and depress the activity of rabbit alveolar macrophages in no way can be related to their biological activity in the whole ' animal. There have been many attempts to make such blanket corre lations, but they have failed. Dr. Cook does correctly state that the cytotoxic effect in in vitro tests have not been associated with carcinogenesis. Unfortunately, Dr. Cook fails t'o note that the fiber samples being used in these tests are not at all representative of the fibers which are emitted from the Reserve Mining Company's taconite processing plant. These fibers were produced from a geological curiosity found' by IITRI personnel during a very thorough explora tion of the Reserve Mining pit. This sample represents an almost asbestiform occurrence of the mineral cummingtonite, which is - normally carried through the processing system. It was ground to produce a sample which contained fibers, 85% of which were less than 5 micrometers in length. The remaining 15* contained fibers up to 100 micrometers in length. By comparison, the airborne fibers from Reserve's taconite processing plant contained probably less than 1% of fibers greater than 5 micrometers in length. To the best of our knowledge, there are no reports of fibers in excess of 10 micrometers in length. Therefore, the fibers being tested by EPA, as referred to by Dr. Cook, are not representative of actual human exposure to amphibole fibers emitted-from the . Reserve Mining Company's taconite processing operations. Since these fibers are not representative of human exposures, the data which ultimately will be forthcoming from these tests will not be useful in assessing the potential environmental health hazard associated with airborne mineral fibers-emitted during taconite ore processing at the Reserve Mining Company's operations or else where. It is interesting to note that Dr. Cook only refers to Reserve Mining's taconite operations as if there were no other taconite processing operations in this country. Based on the title of his draft report, one assumes he would have examined emissions from other taconite operations. Page 2, paragraph . In the final paragraph on page 2, Dr. Cook refers to two. studies in which minerals other than asbestos have produced mesothelioma. However, neither of these studies are supportive of Dr. Cook's short fiber hypothesis, since in both studies sufficient concentrations of long, thin fibers were present to produce mesotheliomas.- Page 3, paragraph 1. We are assuming that in the first sentence of this paragraph, Dr. Cook is referring to the amphibole fibers which were specially obtained for EPA's studies. However, as pre viously indicated, these fibers are not representative of actual human exposure to taconite emissions. Dr. Cook is correct in noting that at this time there is no evidence of fibrosis in Reserve employees with more than 20 years' employ ment. Dr. Cook further notes that these studies cannot be extended to conclude that increased risk of lung cancer and mesothleioma is UCC 007451 A 2 0 8 r\ -7- absent. While Dr. Cook'is correct In this regard, ho attributes this solely to the low exposures to fibers. While Dr. Cook may be correct, he totally ignores the possibility that the fibers to which the Reserve employees were exposed are too short to induce fibrosis. Dr. Cook also fails to note that in other populations occupationally exposed to asbestos for periods of less than 20 years, an excess incidence of both lung cancer and mesothelioma have been reported. It is irresponsible for Dr. Cook to fail to even consider the possibility that the dimensions of the fibers to v/hich the Reserve employees are exposed are such as to render t.hem biologically inactive, regardless of the level of exposure. Page 3, paragraph 2. In the second paragraph on page 3, Dr. Cook is guilty of not being objective about his work. In effect, he . is saying that anyone who gets results which agree with him is doing good work, whereas others are using "inferior analytical techniques." There is considerable debate still going on regard ing the reproducability of analyses of environmental fiber concen trations. EPA is well aware of the problems in this area, and has reached the conclusion that it is impossible to regulate fiber emissions into the air without a reliable analytical method. Experts in this field generally agree that the Environmental Sciences Laboratory at Mt. Sinai in New York and Dr. Cook's labora tory in Duluth generally obtain higher fiber counts..than other laboratories. Regardless of the accuracy of Dr. Cook's reported findings, we are unable to determine the relevance of the state-, ments he makes- in this paragraph to an assessment of potential environmental health hazards associated with airborne mineral fibers emitted during taconite ore processing. Page 3, paragraph 3- In the last paragraph on page 3, Dr. Cook makes the statement that "the dose response equation for humaninhaled fiber exposure is not well established..." To the con trary, the data do show a dose-response relationship with regard to asbestos exposures, even though the precise level at which there will be no adverse impact on morbidity and mortality is not known. However, we believe that a critical review of the best available evidence indicates that a time-weighted average health standard of 2 F/cc will not have any adverse impact on the morbidity or mortality of individuals occupationally exposed to asbestos. As Dr. Cook recognizes, the amphibole fiber concentrations in the air near the taconite processing facility at Silver Bay, Minnesota are far less than the current OSHA permissible exposure level of 2 F/cc. Dr. Cook then goes on to imply that there may indeed be a health hazard due to the consideration of such factors as 2^-bour per day exposure, etc. However, there is no foundation upon which to even base an implication of a possible hazard. Two paragraphs earlier, Dr. Cook notes that there is no evidence of fibrosis in Reserve Mining Company employees with more than 20 years' employment Yet, most of these individuals received a 2iJ-hour per day exposure, if one Includes the time spent at home and otherwise in the UCC 007452 A208 -u- neighborhood of the facility. The literature, if showing nothing else, shows that background concentrations of asbestos are un related to any increase of disease. In addition, there is no evidence of any excess disease from non-occupational and non-para- occupational exposures to asbestos. As we previously indicated, Cuyler Hammond's recently delivered paper at the New York Academy of Sciences meeting reported no. unusual incidence of cancer among people who lived in neighborhoods near an asbestos plant in . Paterson, New Jersey, while at the same time the employee populatlon at that plant have exhibited a high Incidence of asbestos- related disease. Page The last page contains many citations from the original Reserve Mining trial and the decision from the U.S. Circuit Court of Appeals. While these may represent findings by the District Court and Appeals Court, they cannot be taken as scientifically . factual. It is disturbing to think that EPA, or any other govern ment agency, would even consider making health hazard assessments based on court decisions, rather than sclentifica data. Since when has our judicial system become the source of complex scientific determinations? In summary, we have read with interest this as well as previous publications of Dr. Cook. In manuscripts that describe his analytical studies and other research, we respect his qualifi cations. We are at a loss, however, to understand or appreciate his qualification to prepare a critical review or assessment of a situation in which "Environmental Health Hazard" is the shibboleth by which regulatory action is proposed-. Equally astounding is our information that Roy Albert has used this Draft Report as the basis for the conclusion that a health hazard has been demonstrated incidental to taconite ore processing. UCC 007453 A208