Document e5qNNG6v7Q6y6Bywz1mN61BJM

INDUSTRIAL HYGIENE FOUNDATION OF AM E RICA. I N C. Mellon Institute. 4400 Fifth Avenue Pittsburgh. Pa 15213 PROGRESS REPORT NO. 2 on Fibrous Dust Studies ' for Johns-Manville Corporation PPG Industries * Pittsburgh Corning Corporation 0'T,ens-Coming Fiberglas Corporation . by Paul Gross, M.D. Director of Research Laboratory Robert T. P. deTreville, M.D. Managing Director June 196Y am association or INDUSTRIE row tmc aovauccmcnt or ncavthtul wmins conditions f *. ...... *4 1 - J 3 % M .* 4 M ;; l-r 7"-- %. a W 4\ r'T /' '"TV^n fli * *. * to' O A / * *to W* l ^ A4a V W* .'Uriuiv r.srmiK i-nr.i i:nu AVE^ri- nTTsi::!i!i:ii, jm. issia PROGRESS REPORT NO. 2 ua FIDROUS 131*37 STUDIES jor FllTSsVHGIJ CORXJXG CORPORATION jrvi-: `07 INDUSTRIAL HYGIENE rOUNOATION or AMERICA.INC 1.. Concerning the specificity of ferruginous bodies, in the first stage of this investigation, it has been found that ferruginous bodies, indistinguish able from asbestos bodies, are formed in the lungs of hamsters in response to respirable filamentous particles of such non-asbestos materials as ceramic aluminum silicate, silicon carbide, and glass. The importance of these findings may be judged from the attached correspondence with the editor of the AMA Archives of Pathology; Accordingly, Dr. Paul Gross has prepared a letter, transmitting a'manuscript based on findings in the Foun dation's laboratory for consideration for publication in the same journal. The letter is dated July 19, and the manuscript will be forwarded that day if no objections are received. We believe that the best interests of the spon sors will be served by its publication in the most expeditious manner possible but transmittal may easily be delayed temporarily if questions arise or if it seems desirable to do so. * II. With regard to the pathogenicity of respirable fibrous dusts of dif ferent composition, results reported below are based only upon a study of accrued mortality in each animal exposure group (either due to pneumonia----- or repeated intratracheal injections of dust). As such, the findings are very preliminary and require substantiation based on observations of animals still on test. \ 1. "Glass a. Glass (uncoatcd). In hamsters, this dust evoked focal macrophage reaction with associated ferruginous bodies. No fibrosis was INDUSTRIAL HYGIENE rOUNDATION or AMERICA INC 2. observed. In rats, no alveolar mural changes were noted. However, in several scattered bronchioles, there were obstructing polypoid structures of inflammatory fibrous tissue that enclosed numerous glass particles. This bronchiolar inflammation is attributed to the entrapment (at the site) of large aggregates of interlaced glass fibers during the intratracheal injection. b. Glass (coated with phenol-formaldehyde resin). As with the uncoated glass, this dust produced no discernible alveolar mural lesion; but, because of the impaction of aggregates in bronchiolar lumens, there were lesions in these regions of impaction comparable to those des cribed.above. c. Glass (coated with textile binder). Still in prepara tion. No progress to report at this time. 2. Ceramic aluminum silicate. The pulmonary reaction * / to this dust in hamsters was similar to that observed with glass dust ex cept that ferruginous bodies were more plentiful. No fibrosis was demonstrable. In rats, there was an occasional bronchiolar polyp of inflammatory tissue enclosing refractile fibrous dust particles. Occasional small col lections of alveolar macrophages were also seen. There was no evidence of alveolar wall fibrosis. --------------------------3. Organic fibers. This material was either rapidly re moved or underwent resorption because considerable difficulty was encountered industrial hygiene FOUNDATION or AMERICA.INC 3. in recognizing evidence of dust injection. Few small collections of dust- containing alveolar macrophages were observed in hamsters and rats. There was no alveolar fibrosis. No ferruginous bodies were found in the lungs of hamsters. i 4. Attapulgite. Aside from scattered small collections of alveolar macrophages, no other significant abnormality was observed in the lungs of hamsters or rats. No ferruginous bodies were found. 5. Natural chrysotile. In hamsters the pulmonary reaction to this dust consisted of a diffuse proliferation of alveolar cells and macro- phage reactions. Many asbestos bodies were present among these cells in the air spaces at nine months. In' rats, the reaction was multifocal and consisted of mural fibrosis involving respiratory bronchioles, alveolar ducts, and their evaginating alveoli. 6. Synthetic chrysotile (Grandquist). In hamsters this dust provoked a moderate macrophage reaction. No ferruginous bodies were found. In rats, there were initially only slight focal alveolar cell proliferations associated with collections of macrophages. Nine months after the intratracheal injection of the synthetic chrysotile, there was questionable thickening of the wall of some respiratory bronchioles. There was no active inflammation and no evidence of fibrosis. ~ 7. Synthetic-chrysotile (Grandquist) plus adsorbed^-nickel__ phosphate. The pulmonary response to this dust in rats was characterized INOuSTPIAL HYGIENE rOUNOATION or AMERICA.INC 4. by-a moderately intense multifocal inflamn'.atory reaction centered in the respiratory bronchioles. The inflammatory reaction at the nine-month period included the proliferation of fibrous tissue which obliterated the lumens of the air spaces. This reaction greatly resembled that produced by natural chrysotile. No ferruginous bodies were found. 111. A supplemental study was designed to explore the etiologic role of e various components of chrysotile asbestos in the production of lung fibrosis and/or lung tumors. For this purpose, the following series of rats have been injected intratracheally with suspensions of the following materials (all of them of respirable size): 1. Chrysotile dust known to be carcinogenic 2. Synthetic chrysotile 5. Synthetic chrysotile plus nickel 4. Synthetic chrysotile plus chrome *v 5. Synthetic chrysotile plus nickel, chrome, and benzopyrene 6. Nickel with carbon as carrier ?. Chrome with carbon as carrier 8. Benzopyrene with carbon as carrier 9* Filamentous glass with phenol-formaldehyde coating 10. Filamentous glass with textile binder coating TT. Filamentous glass-, uncoated. INDUSTRIAL MYOlCNC FOUNDATION OF AMCRICA.INC 5. As mentioned in II above, concerning results of the preceding phase, data arc available only from a relatively few spontaneous deaths which have occurred and such tentative findings as have been observed, and their inter pretation, are included in the above discussion. It appears at this point that the trace metals, injected as particulates into the lungs, will probably not be biologically active. It will probably be necessary or advisable to sup plement these series by injecting rats intratrachcally with synthetic chrysotile to which the trace metals hdve been adsorbed in a manner similar to that used for adsorbed nickel phosphate. Comment on Findings to Date The appended manuscript furnishes irrefutable evidence that ferru ginous bodies indistinguishable from asbestos bodies may be produced in ' lungs from certain non-asbestos filamentous particles of respirable size. Data so far collected shows that such dusts as aluminum silicate, silicon carbide, and glass, all previously shown to be "biologically inert, " will produce ferruginous bodies when injected into the lungs in filamentous form and also confirms their lack of fibrogenic potential. Therefore, there is no reason whatsoever to equilibrate production of ferruginous bodies and pathogenesis. Further data are needed to extend these observations to include lack of cancerogenic potential, however. -APPENDIX A cjCelleri to the ^lililor TODArS PRESSING QUESTION--HOW SAFE IS URIAN AMIIENT AIR? To thr Editor.--Professor J. C. Thomson nude * a notable contribution to patlmlogy when he an nounced ilte discovery ol "asbestos" bodies in tlie juice nf limes taken from nonoecupatimully ex posed urban icpulation of Capetown. South Africa.' Unfortunately, the far-reaching conclusions he lias derived since, resting upon little or no evidence, tend to detract from the value of this finding. In the present paper (Arrh Path SI :45S, 1966), professor Thomson has shown an awareness pf-- but dismissed too lightly--die obvious objection to his thesis, "the suspicion Out asbestos fibers are now a hazard of urban living is confirmed more amply than expected." This thesis appears to be based on Dr. Thom son's premise that asbestos bodies are specific and do not form m resj-mie to other materials. As pointed out by Thomson there are. m addition to the "Curious" bodies, also so-called pseudoasbestos bodies. The Utter, he rightly differentiates from true asbestos bodies by the opaque, irregu lar. central cores. . The pressing " question today b the following one: Arc there materials ocher than -ibestot. that are of filamentous character and manufactured to day, that are part of ambient urban air. and that will stimulate alveolar phagocytes to produce asbestos bodies?* These materials could probably be classed mostly as pUsties and would, most likely, have one important feature in common, namely, a biologic "inertness." As a possible example, one might consider that filamentous plastic dust has been produced in homes from carpets woven of synthetic yams. The use of vacuum sweepers cqnipped with high-speed beaters would tend to reduce same of the fibers to a respirable particle size. It is a curious faet that no publication has appeared describing the pulmonary reaction to such dust There is, of course no answer to this question at the present time. Yet. far from accepting Dr. Thomson's assumption that asbestos hodics are specific for asbestos filers, the US Public Health Service has recently authorized and funded work in several laboratories in the United States to ~&ite*tfgate this question to* wU as-others) to the tune of over $600,000. A number of other statements in Dr. Thomson's paper deserve comment. His declaration. "There are statements in tlac literature on asbestos, mainly by people oilier than pathologist*, that the asbestos Uly is nonspecific. These opinions arc not held by liistnpatlmkigiklt today . ..." is nut necessarily true. I. for one. Dr. Arthur J. Vurwald.* Dr. Joint U. fi. Davit,* of Camhrklgr. England, anil Dr. A. G>llct * in Dr. Pdicard's lahuratory near Paris have open minds set this problem. Anotlicr statement requiring correctset. based apparently on inadequate information, is tliat. "Man and the guinea pig seem to he the only animals in which abrst. fibers are regularly and rapidly converted into asbestos hndies." Waener* found asbestos bodies m else tunes of rabbits and monkeys exposed to a*brtus dust. We have fount) almiwlant asbestos bodies in the lungs of hamsters exposed to chrysolite asbestos dust* . Because of lie present uncertainty regarding the specificity nf the asbestos body, the term "ferritin" body was sacrested. This term was criticized because the composition of ferritin has not been adequately characterized. Perhaps the use of the term "ferruginous" body will serve die purpose until it can be shown that these structures are specific for asbestos fibers. Dr. Tltomsnn declared that, "Many of the very thin and sharp asbestos fibers more downward toward the lung bases owing to lung movement, cardiac action, and gravity." In the presence, of "dry" lungs such transport of asbestos fibers and ferruginous bodies would necessarily (at least in the lower lobes) have to go counter to the muco ciliary escalator--a frat which is difficult to imagine. A more reasonable explanation of the ob servation that ferruginous hodics are more abundant in the basal portions of tlie lungs is that in many . people dying of natural causes, this is -where fluid tends to accumulaW terminally. Under tlie latter conditions, thr opposing action of the escalator mechanism b overcome by the sheer volume of find rolling osar the mucous blanket like tidal waves with every inspiration. According to this concept, the concentration of ferruginous hodics in tlie basal portions of thr lungs would have no qfmkal^ implication except that nf a terminal event similar to, if not identical whit terminal hypostatic congestion and edema of the lungs. Paix Gaos*. MD 4400 Fifth Are Pittsburgh I12U REFERENCES 1. Thomson. JG. el at-* Asbestos as Modem Urban Hazard. S Air Med J 37:7741. I9M. 2. Dart*. J.MG.: Ekcvoe-Microseope Studies of Ashesiosb in Man aad Animals. Atm NT Aeml Sri 132:99-111. 196J. ------------------------------------------ 3. Vorwald, AJ.: Personal cnmmanicatina to thr author. May IO. 1064. - 4. Davn, J.M G.: Personal communication so ite author. May. 1944. 3. Collet. A.: Personal communication to the .author. May. 1944. 4 Wagner, J.C.: Asbestoses in EipcrimeiMal Animals, -Writ J lujuur Mrd 29:1-12. 194). 7. Cross. P,, and deTrrville, R.T.P.: Progression at Asbestoses, hi he published. To thr Editor--Tlie criticisms hi the letter l IV. Gross which call te a tvpiy are nmemml Arth Path--Vml S3. Aap PM* LLTTLKS TO THL LblTUK with tlw <|>Tilicitr of inlirMm Iodic* ami with lie mownKill-, ni lilicr* in llic Innnan. |ir. <>r*i** acrw* mill me tliat tin- |i*rmWulw.-*t<i UkIh-* ran tc ilitlrrmtiatnl irtan tlie genuine a*l-*tn* l*lic* by tltr nautrr of their central rurr*. hot iii*u-ad oi rrwicluding, a* I do, tint trite a*l<r*i<>* UrIn* are arcqitaldr marker* of i*lw*t>* Moulatnio. hr |a>*tukitv that syntlwtie fihrrt are promt in nrlan air aral might lead to the produrtimt of a1ic>to* bodies. 1 tin not know of any rviilmre to tliat effect. He gw on to discus* in particular filamrutnu* durt from carpets woven irien synthetic yarns, amt cxprcMcs-surprise that i> iiuhlicatkm ha* appeared on tlie pulmonary reactm n to *ach iluM. I am not surprised. as these symltctic filer* arc elastic and not of the type tint pneluces fine duL but if such a publication d>* api>rar I shall be more surprised than Ur. Gnws if it includes a description of ashrstp* bodies, as tlie man-made fibers in carpets are much thicker Ilian the fiber in the center of an asbestos body. Further, to pet fragments as short as asbestos bodies, averaging 40p to SOp from synthetic fibers would imply brittle characteristics which these plastic fibers do not possess, and would require something more than a vacuum sweeper for their production, if tiny could be produced at alt with out the use of a microtome or oilier cutting tool. Unless one can suggest an inhaled material with the features of an asbestos fiber inside an asbestos faudy with a length of 5*t to ISOp and a thickness of ip or less, as Dr. Gross has (ailed to do, it would seem more logical and practical to regard asbestos bodies as markers of asbestos inhalation, howevrr unwelcome or inconvenient to some that conclusion may be. Dr. Gross suggests that my statement that man and the guinea pig appear to be the only animals in which asbestos fibers arc regularly and rapidly converted into asbestos bodies is iurorrett. and aa support mentions that asbestos hodies have bren fouud in the lungs of rabbits, monkeys, and hamsters exposed to asbestos dust. He could alto have added that one author on one occasion saw one asbestos body in the lung of a rat exposed'to asbestos dust; it is equally irrelevant, t was dit* cussing the animal species that regularly aid rapidly formed asbestos bodies, not those in which they wuuld he found. This matter it not an unimportant one, and it would seem desirable in experimental asbestosis to me not rats or rabbits, but to use the guinea pig, tlw animal flat consistently show* a pulmonary response to asbestos fibers similar to that in man. 'wilti The-production of-pulmonary fibrosis-os. well, as of asbestos bodies. Most important perhaps is tut last paragraph concerning the movement of asbestos fibers. Dr. Gross omits the first part of tlie quoted sentence and that which follows it. in which I stress that while tlie needle-like asbestos fibers can move downward*, tlie asbestos laaly with its slurp points blunted by the protein and iron cncrustatiop can nut. Ilv. luiuvvvr. dicn**c* tlw im|ii*iLlnl;i> nf tlw Imttiuard ih-***nt of a*l*-*l** tilwf* **! aslwstu* hulk-* ii an c*iual Ui*i*, put* rwar-'. ivilka ni tlw only |**tldc tiweliatii*ni of thi*. ..i >1 thinks very little of hi* own suggestion. On tin* v.i arc in complete agm-nwnt. imt lie ikws not csim* cm tlw idwinu* inccliaitism in the article. The evidenrr tliat asheslo* filwrs before tlw> U come asbestos l*lic* tmw'C downwards ami laii-ialh from lung murcnwiil* ami gravity i mfetvntial. Un dues explain some >4 tlw unu*iul feature* asbestosis, which are utlicrwa*c incxidwaldv. 11* main objection to it as far as I can v i* llt.t it introduces a mude of transport nut jifisiit in tlM-r varieties of pneumoconiosis, but ullwr piwinmi- coniote* are not due to thin sharp filter*. Tlw hula containing tlw necdlvlike sharp fihrr* of aslw*i -* could be regarded as a shaking machine, ami mm which is always in action as the lung is never at rvt The fibers we are discussing are often too long to Iw phagocytoscd by dust cells, and would tend to downwards m the erect pusturc omipied hy m -t human beings for two thirds of the day and laterally lor the remaining third during sleep. This explain* why asbestosis is more marked at the base unlike other pneumoconioses such as silicosis, which is mar* marked in the apical portions of tlie upper lobes; why pleural plaques, calcified or not. i--u accepted hr most as resulting from inhalation asbestos, are present posteriorly and laterally in tlw parietal and nut the visceral pleura; why they'arc more common inferiorly than superiorly and arc i>t shed anteriorly, as adults rarely io the pn position. Use movement of these asbestos filer* outwards from the lungs explains why such pleural plaques are initially seen over the unyielding rib* and not over die soft easily penetrated intm*i.-d regions, and for tlw same reason are found in tlw diaphragm over the tendinous purtinn. and me tlw muscular portions. It is probably the rraxm why these pleural plaques are seen more frcqunnly in cases with little or no pulmonary asbestosis, as tlwrv is no pulmonary fibrosis to block their outward passage, and this may well Iw the explanation 4 tU- apparent paradux that malignant mesothelioma* <4 pleura arc Ken more often with a mild or trifling asbestosis than with a severe classical ashrstosi*. It it a rational explanation why these mild cases asbestosis may be associated with a malignant im thclioma of the peritoneum. It is surely significant that bare asbestos fibers, but not urnnohile aslnM<* bodies, have been demonstrated in all these extra* pulmonary lesions. To conclude, perhaps k would be easier tu appteemte the basicdifferences between othct-piicinu!iconknei and asbestosis and ks complication* if stopped talking of asbestos dust, and used in*t-.,.l the term employed in the German litrraturv--a** bestos needle*. J.G. Thomson. Ml* Medical School Cape Town. South Africa Artk Path--Pal K. Aug 1966 APPENDIX 13 Cctlcrd to the diIor REPLY TO DR. THOMSON Tu Ihf lidtl-t.-- In Vx- ad Hi* *L.-|i(iciun. Ammvfc.* w l'.iTinj;r IJ:tl).vlVi (Ansi I'Mi, cnnccrniiiB Ir. (in%` lint iiminrral. filammtnu* alu*t |nirk* nuy Hr |ire*a-ni in tlic aniliicnl air. omiiiarjMa- in *iir In iliat an fik-i. tlut luvr raiiM-al llie aU-val pmmt ( hlie*. Ilr. Tl*n*am will find tlic atlaclwal micraraph* ad intare*l (Fie I ami Jl. .Vmnernu* aurli fikri wrrr fnund in nrdiiurr Inhw a|u*l anal llwir ali*appcarance am mirruineinrratiin pr w lint tlwy are i4 a*l**t<a*. Ilr. aqainrm flat naamtincral liU-r* in amiamt air arr la* Millirimlly fine In (asm (lie mm arf (erniei<*m laalir* i tint* alcfiuili-ly aa|m tai a|ilr*tinai. At |Si*anl. Ilr. tin*** i* altcni|itins to ri.*vt-lnp tactical tni'isnialHt pavrniiis janadiirtam <4 ier- rnpinam* laalie* in mi a variety n{ (ilsnti* du*tv I)r. T1kim*aai i ms in a |aititm tu *|<cak iiv Fir 1 .-/-((. FiHmu* durt panicle oi 3u diameter and approximately 4(lu in length betas* micTtsncineratrm. Hight. Same after micniincincratkin. Tlic particle Hu diaappeared. Fhr '--/.</(. FiHmoa dtw particle .V<m Hi diameter ami mure than MOp Ions hefure mitruincineratiim. A'lj/Af. It. too. Iia diMappeared in tlic praam* ad niirroincinrratinn. unriihs to Tim mu ftik alt lii|niullA<i>lwrrUmly 1*4 fur Dr. (iron I or lor tlic oiIk-t rx|x-rt' l(m Ik I'liiliil Stall-', (iri-at ISriutn. amt France li-icd in llr. (r*>' ktli-r 1--011 tltc nuttrr of |fituilN of hrm-nt-mhalir> l\ being call'd! <aily by aslK-stoi. In Ins rtlmital of I>r. limn" Irtlrf, lr. TIkkis-io attain apicars to atn-ni|it Ui s|n-ak for tlic |Kofvion lirii Ik- -ays tliat pleural plantir> Hum arr "accrtttnl by iiKKt~ ax resulting (rim mlulataai ol a'ln-slns. In a recent monumental study invoking 4.11 dxiMrntivc autopsy cases. 3Jcurman' cmwtudcs <1> Ml: "Tlic frequency of n<n -ith plannc* xa> Isait tlic same in two of tin- three lm->|iital districts investigated in different part* of Finland. whilst in tlic third it wax lower. Plaques proved to be an equally common finding in a district in South* wext Finland with no aslwxtnx ilepoxits and no partieular asbestos industries. ax hi a dixtrict in Kaxt l-'inland with an asbestos mine and mill and extensive anthophyllhe axhexUM tlepoxitx near itx caxtern hnriler. Plaque* were encountered hi 52 of the urban population and JU^c of tlic rural population." The purimieful puhlicathai of ermnmux assump tions, wliicft have no apparent bati* in fact and lave primary emoliiaial a|-t-al wa crilh-i/nl ly tlxe late llr. Frank l*riiH-i- in ln t'Uairmau'' \*ldrvs* 1 Meilical Prrsia-ilivv in AtmosplK-riv llygieiH-l lief<iri- tin; ,\M.\ SovnttiH" Ss-N-s-11 i l'rcventiNi- MediciiK- in I'XiJ as Ihhij far common, lie calleil for adlK-rvnce to tlic xeiculiiic metis a) on tlic part of soculi-ts. indicating ll-ir rrspnnsiUlitics In the pnldir a well a* to Minnin xurli matterx. Those wlm liave re<t kaw should review llr. Princi's articir hi light of iIkprescut di'agreement ami Ik- ponied accordingly. In tlic present state f kiwiwUslge. Ur. 11xnn>i`s hisixtencc *m llie *|K-citicity of ferruehnnix llr. and |dcural plaques for iJx-Mm lihi-r' i in-l justified scimtificallv. Robert T. P. dcTrcville. Ml) 4400 Fifth Ave Pittsburgh ISili Refer*new 1. Meurman. L: Asbestos Rodiei and Pteurat Plaques in a Finnish Series of Autopsy Cases. Aeta Taih MicnMot Scand (suppl) 1(1:1964. 3. Frinci. F.: Medical Perspective in Aimoxpheric Hypcne, JAMA 1(2:630-633 (Nov 10) 1962. RAPID HISTOLOGICAL DIAGNOSIS . Ta the Editor.--The supravital technique for making fast tissue diagnoses at the (fcffe'of surgery was simplified twenty years ago.1-* Since then, the method has continued to ;.`dd its rewards in a few places but it has not gained many aetr adherents. This situation would appear to have been caused by the increasing popularity of the more cumbersome "froren-section' technique which provides more familiar patterns of more embalmed preparations. Our experience with these two contrasting proto types of examination is facing recorded in an effort to verify quantitatively for tlic many wliat may have seemed uhrhms only to the few. The data (the Table) show a very small im provement from 2J% overall error in the period when unly the supravital rapid-section (R-S) technique was employed (I95d-19<i2) to I.O', in (he later period when cryostat microtume fruxnisection methods were aildetL This may I* at tributable to an increased breadth of experience and improved judgement over the years, rattier than to methodological difference*. Ehlier figurv campares favorably with the -'r overall inaccuracy cited by other imt(iptnn.l` In the later period (I%i2-I964), where tlic desirability of employing an added f fnsren-seetksi 1 technique was determined fay the difficult** of each case, it i* paradoxical that the only false positive error* occurred in sellings where tlw aifclcd effort was not made, and may he an exprcssaai *-t in irreilurihle minimum of failure of performan-c. More important than numerical data arc tlw Data Shamag Cautratt Betvxen Frasen-Srctina and K-S Teehniqaet i*a- IMS IMt- IMS Taula uu 4 aatar 9M g-Oeahr Fraaew + K3 Sit su Taha Faahlsa Ka. G a LS a M a 4.7 a e.e False Moralise Me. IS "l# 11 M 1 U ( 14 False *<+ Me. li M 14 14 14 ( 14 l*4(t No. G M - It u (4 H 44 Arch FuM-fo/ M. .W 1966 Ns Te Fanisi *r Defer Ns A Ml IM .Hi.. tat Ml M.7 M 114 M9 M.7 ni M.4 M U M 17.4 APPENDIX C Amrhican Mi:i>i<\\i. Association 535 NORTH DEARBORN STREET CHICAGO. ILLINOIS 60610 PHONE (312) 527-1500 TWX 910 221-0300 0. MURRAY ANGtVIRE, MO. CMC4>t* OtMMI * PMIMI#*, Wmmily M Mikmxui ScM*I HMMKm* 410 Hm CkJfWI SUttt Minin. Wittmf S370S JOHN H. TALBOTT, MO, OiiiCtw 0m> M IcitMiliC PbliC4t*0ft ROBERT R. MATO. CatCHln* Mjni|*A( (OM NORMAN 0. RICHtY, kMt*| CilK Robert T.P. de Treville Mellon Institute 4400 Fifth Avenue Pittsburgh, Pennsylvania 15213 OKONtS or MiMiocr 10*10401. (Oils arc nit n. BACcrmtinx vr>, oc vir.. t* MNNTTM M. ARinamu."-. VO. r* jOStPn FCLOMAN, vf>, l. < >.. Cm i. SAMUIL P. NICKS. MO. A-r A.jai, ,<. PAUL KOTM, MO. #<NI-L.. . PAUL t. LACY. MO. Si. Lfcn KCNRY 0. MOON. MO. l Fi Wiki JOHN L. SMAPINO, MO, IMtMnHi, Im. C. BltuCC TAYLOR, MO, [.!*, IIL Dear Dr. deTreville: The enclosed copy of a letter to the Editor from Dr. Thomson. Since I did not forward (probably an error) your letter to him, I believe his letter should be published. Z believe this interchange should now be terminated. I trust this will be agreeable to you.*' Sincerely yours. jmlA /> A- -4, D. Murray Afj'gevineJ M.D. Chief Editor Archives of Pathology DMA:eg LFHTRS TO THE ESJTU Hauly to Dr. de Treville'e let'er. To the Editor, - In my reply to Hr. Cross' suggestion that non-mineral filsaentous dust particles could fora the centiv cf asbestos-like bodies, ay coairer.t was that "unless one esn suggest an inhaled-material with the features of an asbestos fibre inside an asbestos body with a length of to IJOji and a thickness of V* or less, as Sr. Gross has failed to do, it would sewa wore logical and practical to regard asbestos bodies as markers of asoestot inhalation, however unwelcome or inconvenient to some that conclusion may be." Sr. de Treville, Archives of Pathology C2i 496 - 497 (Kov 196c}, in reply to this, produces photomicrographs of non-asbestos fibres with thicknesses of }u and 3*$u, ana on this concludes that ay opinion that "non-mineral fibres in ambient air are not sufficiently fine to form the oores of ferruginous bodies (asbestos bodies)" is thus open to que^t^on. My opinion, -of course, is still opeh to question, tut the average thickness of the asbestos fibre in the centre of the ae&estos body is 0.*yu, without considering the miniature asoestos bodies deoonetrated by the electron feicroscope, and all Sr. de Treville has done is to fail to find any non-asbestos fibres in household dust as thin as those in the centre of asbeetoe bodies. - 2Dr. de Treville next accuses me of attempting to speatt for the profession when 1 say that- pleural plaques are now "accepted by most" as resulting fiom the inhalation of asbestos. His only support for this is to quote a paragraph from the monograph by Msurman stating that pleural plaques were about as frequent in a district in Finland with no asbestos deposits and no partioular asbestos industries, as in a district with an asbestos mins and sill. This is preceded by a statement that "Moorman concludes", but the quotation Is from a summary of his findings (page t>3) and not from his conclusions which are given later (pages 97 - 99) under the heading of General Summary. Dr. Msurman naturally discueses the evidence for and against the relationship between asbestos Inhalation and pleural plaques, and it is an'easy matter to select from this discussion (pages 87 - 9b) opinions against that association* Msurman'a opinion on the relationship between asbestos bodies and pleural plaques is vary clearly stated jr hio aianmry. "Plaques were observed in $2*2% of the urban population and in 31*o> of the rural population. In the rural districts eases with bilstersl plaques were more frequent than plaquw-l'rwe cases only in the asbestos mining commune and in one of its neighbouring communes." "Asbestos bodies in the lungs and pleural plaques occurred mors often in conjunction than separately, the difference being very highly significant". "Ths present results seem to indicate that pleural plaque formation,- in particular wl*ir'tt"ti---------------bilatoral, and the occurrence of asbestos bodies in ths lungs, have some astiological factor in oommon. The dust that induces the formation of atbestoe bodies does not, however, eoem to be the j eel* causa of plaque forcatior.''. iteadara of tbio correspondence m.y judge for tbeaiici'/ea wfetLer Dr. da Treville'a quotation froa Kejrruan gives a ccrrec or ineor:*oct iaprsscion of Ir. Haaroa.'o opinion on tha relationship between aalestoa inhalation and asbestos plaques. J.C. THOMSON, K.D. Medical School Capo Town, South Africa *v Nol<* on copy of 1 ransaetions: APPENDIX D Dr. Anprvim* -- PJi*ac p. 11J for ;* piclui t* *f a frrru^initijx body product**! by Dr. Gn.s.H. UTIJ dcT. March 8, 1967 Dr. D. Murray Aagevine Cblal Editor. Archival of Pathology Dapart.nasi of Pathology University of Wlitoaiia School of Medicine' 470 North Charter Street Madiaoa. Wisconsin 93706 Dear Dr. Aagevine: Regarding Dr. Tbomooa'e reply, by way of review. it should be re tailed that the following two basic assumptions i& his paper (Arch. Path. 81:458, 1966) were challenged: 1. that hietepathologlets today do act bollove that the asbostoe body, may bo nonspecific. aad i 2. that it ie ao accepted by moet that pleural plaques result from iahalatioa of asbestos. --j la a paper givea la October. * D*. Paul Gr*so reported oarly findings of his research* oa production of ferruginous bodies otth non-asbestos filamsstous fibers of rospirabls also. Scientific questions art properly sottlod by coaslderatioa of such data, not by opinions. The very aaiateaca of Dr. Cross' research is adequate proof that Dr. Thomson does not speak for all hlstopatholagiets today concerning specificity of eo-called asbestos bodies for asbestos in halation. Meurman's findings, mentioned by Dr. Thomson, are la accord with these published earlier^ by Dr, Konneth Smith, who said, "If inhalation of the asbestos fiber alone could cause pleural plaques, one would expect to find plaques whs revs r tbs fiber is used." Meurman's conclusion that "the dust that iaducss the formation of asbestoa bodies does not, however,'seem'io'bo the eole cause of plsque formation" doee not appear to bo consistent with the second assumption of Dr. Thomson. Further work is certainly needed to shed light on this important area* as the occurrence of forruglaoue (eo-called asbestos bodies) has been found Ur. T' J. urry Angaria* K trch 8, 1*07 Pig* i in almost halt (48-) of iho Individuals studied at autopsy in Montreal by Tl-uribsck.** Fortunately. plana for such aro baing mada through cooperative afforta involving Industry. government, universities and private institutions, aa vai pointed out in a recent meeting held by Industrial Hygiene Foundation (XHF) and reported in tHT Medical Serlea Bulletin No. 11 entitled "Asbestos Bio* effecta Research for Indnatry. *J A limited somber of copioe of this publication will bo made available to roadara of Archives of Pathology upon request with out charge while the supply lasts. Slncoraly yours, deT:sjc cc: Dr. Paul Grose bcc: Mr. E. K. Davison Mr. Hugh J ackson Robert T. P. deTreville. hi. D. Managing Director 1. Trnneactions of Industrial Hygiene Foundatlon/31at Annual Meeting. 1966. 2. Industrial Hygiene Foundation Medical Series Bulletin No. 11, "Asbestos Bionffects Research for Industry," 196b. 1. The Pneunfoconioees. A. J. Lanoa, Editor. Grune k Stratton, Inc., New York. 1963. 4. The lacldonco of Aaboetoo Bodies in the Lungs at Random Necropsies la Montreal. Lily Aajllvul and W. M. Thurlbock. Can. M*ed. Assn. J. 95, 1179-1182, Doc. 3. 1966. APPENDIX E Amrhican Mkdk al Association 535 NORTH OEARHORIJ STREET . CHICAGO. flUNOtS bOtolO RHONE (312) 527 1500 twx 10 271 0300 0. HURRAY ANCEVIHt, UD. CMI Cdilo< Owwwm d Nnmir Umvmity d S(MOl 0( KMICHW <70 Nom Ckonoi Sumi Mje<too, diKooMO DIM JOHN n. TALBOTT. HO, Oiitctn Oii<on of Uitfltil* Radi.cJtia.nt ROBERT . KAYO, (utotioo Mouiinf Cdila< ROMAN 0. A1CHEY. Mott`I Cdiko IKKIYtS (f ntMOlSCT ftllMIAl ISAM AnCNIE M. 1.1 l.l*'., i'O, (*,..< si,-., M.-il. MHIAIIi U HNiN.ill.v., VO. Cr * i, .C. uni in rtLOuou. vu. i, jri.. cj,'. SAUuEk R. HICkC, S|t, A.W A.oo*, u.Lik, RAUL NOTIN, UO. Sc"*ctM, MC. RAUL E. LACY. HO, S:. I *.,% henry u.tjnoo, cai. \r\ ft*. JOHN L. SHARIHO. U), htftonllC, Tom. C. BRUCE TAYLOR, HD. Cmiioi, m. April 4, 1967- Robert T. P. deTreville, H.D. Managing Director Industrial Hygiene Foundation of America, Mellon Institute, 4400 Fifth Avenue Pittsburgh, Pennsylvania 15213 Inc. Dear Dr. deTreville: I wish to thank you for your letter of March 8 together with enclosures. After careful consideration, I do not believe it advisable to publish further correspondence on this matter in the Archives of Pathology. It would seem'that after the initial exchange of opinions in print that further discussion should be by correspondence of participating parties. 1 assure you that this is not a deliberate attempt to curtail debate but rather than a continuation of it may not be of large reader interest. Sincerely yours. DMA:eg D. Murray A^ Chief Editor _ Archives of Pathology- APPENDIX F INDUSTRIAL HYGIENE FOUNDATION OF AMERlCA.INC. Mellon Institute. 4400 Fitth Avenue Pittsburgh. Pa. 15213 July 19. 1967 Dr. D. Murray Angevine Chief Editor Dept, of Pathology University of Wisconsin Medical School 470 North Charter Street Madison, Wisconsin 53706 Dear Murray: I am enclosing an original and two copies of our manuscript, . "Pulmonary Ferruginous Bodies: (1) Their Development in Response to Filamentous Dusts, (2) A Method of Isolating and Concentrating Them, " together with two sets of illustrations for your consideration for publi cation in the AMA Archives of Pathology. The work reported in this paper is a logical follow-up of the cor respondence between Dr. J. C. Thomson and our laboratory that was published in the Archives of Pathology, Vol. 82, in August and November, 1966. With best regards. PG:ejd Enclosure (Paul Gross, M. D. Director of Research Laboratory am miocmtim or imoustmic* roe thc aowamccmcmt or NCALTeruk wonmo comoitioni APPENDIX G INDUSTRIAL HYGIENE FOUNDATION OF AM ERICA. I NC. Mellon Institute. aaoO Fifth Avenue Pittsburgh, Pa. 15213 PULMONARY FERRUGINOUS BODIES: 1. Their Development in Response to Filamentous Dusts 2. A Method of Isolating and Concentrating Them by * -- -- Paul Gross, M. D. * Robert T. P. deTreville, M. D., D.Sc.* *# Lewis J. Cralley, Ph. D. ** and * / J. M. G. Davis, Ph.D.*** * Industrial Hygiene Foundation *** University of Cambridge 4400 Fifth Avenue Pittsburgh, Pennsylvania---------- British Asbestosis Research Cow __ Department of Pathology Tennis Court Road ------ --- Cambridge, England ** U. S. Department of Health, Education, and Welfare Public Health Service National Center for Urban and Industrial Health Occupational Health Research It, Training Facility Cincinnati, Ohio 4 5202 TON TMC ADVANCEMENT OT MtALTMnik NONAINO CONOft'ONS INDUSTRIAL hygicnc foundation or America.inc ABSTRACT Formation of ferruginous bodies should not be confused with patho genicity. Failure to understand this differentiation may result in the erron eous generalization that all fibrous dusts share the ability of asbestos to produce lung damage. Such materials as fibrous aluminum silicate, silicon carbide whiskers cosmetic talc, and glass fibers produce ferruginous bodies experimentally which are indistinguishable from those produced by asbestos fibers. A method of isolation and concentration of ferruginous bodies from lungs of animals and humans is described. Ferruginous bodies from asbestss fibers are much more pleomorphic than has been described (except by Gloyne and Merewether, International Labour Office, Occupation and Health Supplement, Asbestos, January, 1938, page 7), casting further doubt on * 't .morphological distinctions used in the past in separating so-called asbestos bodies from pseudo-asbestos bodies. industrial hygiene foundation or America.inc Introduction Worldwide attention was refocused on ferruginous bodies by the publication of Thomson, * who found this phenomenon in the lungs of more than 30% of unselected autopsied adult hospital patients in Capetown. A similar percentage was noted in Miami, Florida, ^ 43% in Pittsburgh, 1A Pennsylvania, J and 48% in Montreal, Canada. The higher percentages re ported in Pittsburgh and Montreal are possibly inherent in the more inten sive searches carried out in these cities. These bodies are similar to asbestos bodies though the nature of the central fibers have not been identified Asbestos bodies are golden-brown, ferro-coated formations found in the lungs of persons who have inhaled asbestos dust. They are gen erally described as symmetrical, segmented structures usually with clubbed ends, 3 to 5 microns in diameter and 20 to 50 microns long. The core of these bodies is composed of a transparent colorless asbestos fiber, although this fiber is not always demonstrable. Pseudo-asbestos bodies are similar to asbestos bodies, but are formed in the lungs in response to iifcaled non-asbestos fibrous materials. Apparently the only difference between an asbestos body and a pseudo asbestos body is that in the former, the central fiber is composed of asbestos and in the latter, of matcriaf"other~Hah asbestos.------------------------------------ ----------------- orindustrial hygiene foundation America.inc 2. Since asbcstos>likc bodies can form in response to respirable, trans parent, colorless fibers deposited in the lungs and composed of materials other than asbestos and since classifying these structures based upon identi fication of the central fiber presents difficulties, a generic term, "ferruginous' body, has been proposed for all'bodies formed in response to the presence (in body tissues) of a broad spectrum of fibers, including asbestos. Davis^ and Collet^ demonstrated by electron microscopic studies of macrophages that ferruginous bodies are formed intracellularly by granules of ferritin or a ferritin-like protein that are precipitated upon and around some foreign materials. ____ _ As asbestos body, therefore, is only one kind of ferruginous body, one in which the central filament is an asbestos fiber. As will be seen later, the appearance of these bodies and their dimension are so varied-as to defy the reasonably short description usually employed. The problem now confronting investigators concerns the significance of the widespread finding of ferruginous bodies in the lungs of urban population groups. The solution of the problem is, of course, linked to the identity of the central fiber about which the ferruginous body forms and which is at present unknown. It is hoped that recent analytical advances, such as electron diffraction and microprobe will provide techniques for definitive identification of the cYntra1 fxberT -------------------- INDUSTRIAL hycicnc tounoation or AMERICA.INC 3. Up to this point, the identification of ferruginous bodies in the lungs of unselccted autopsied hospital patients as asbestos bodies* has been based on the hypothesis that transparent fibers of respirable size composed of materials other than asbestos either arc not encountered in industrial and community environments, are not deposited in the lungs, or do not result in the formation of ferruginous bodies when inhaled. Respirable fibers, however, are apparently ubiquitous. ^ They may be mineral, animal and vegetable in nature and from both natural and synthetic origin. They are disseminated through industrial processing, community activities, personal habits, and the action of natural forces. Also, we recently reported that a ceramic fiber of respirable size, composed of aluminum silicate, resulted in the formation of lerruginous bodies. The latter were indisting uishable from some of the asbestos bodies isolated from an asbestotic lung * of a known asbestos worker. (Fig. 1) Although non-segmented, they were golden-yellow, symmetrical, clubbed bodies, staining deep blue with Peris' test and exhibiting a central transparent filament. This paper discusses our further findings as follows: a. Ferruginous bodies are developed in the lungs of hamsters in response to the presence of "biologically inert" filamentous aluminum silicate, glass, and silicon--------------carbide particles. orindustrial hygiene foundation America.inc 4. b. A simple method is made available for isolating ferruginous bodies and bare fibers (inclusive of asbestos bodies) from lungs. The method is given in detail and the results obtained ' described briefly. The Production of Ferruginous Bodies Croups of 12 hamsters each were injected intratracheally with 3. 5 mg fibers contained in 0.5 ml of aqueous suspensions. This was done under light ether anesthesia with the aid of an illuminated, self-retaining speculum that made the vocal chords visible and allowed the insertion of a long 18-gauge needle between the vocal chords under direct observation. All of the following ..were injected: 1. Ceramic aluminum silicate fibers. This is an uncoated ceramic fiber with a median diameter of 2. 0 p. Fifty percent of the fibers were under 75 p in length and many filaments were shorter Jt^an 15 p. No free silica was detected in the fibers. 2. Silicon carbide whiskers. These were 99. 54 percent SiC. They had a range of fiber diameter from 0. 5 to'3.0 p, with a fiber length that ranged from 100 to 750 p. 3. Glass fibers, uncoated. The fibers had a mean diameter of 0.4 p and a mean length of 4.4 p. INDUSTRIAL HYGIENE rOUNOATION or AMERICA.INC 4. Cosmetic talc. Fifty percent of the fibrous material in the talc was under 0. 2 p in diameter and 1.0 p in length. 5. Attapulgitc. Fifty percent of the fibers were under 0. 1 p in diameter and 1.0 p in length. 6. Chrysotile. Most of the fibers were of ultramicroscopic dimensions. Isolation and Concentration of Ferruginous Bodies Samples of lung tissue cut into thin strips three to four mm thick or fragments about 0. 5 cc in volume, are placed in clean glass or plastic containers. To the tissue is added about 20 times the tissue volume of com* mercial 5% sodium hypochlorite solution. This is allowed to stand undis turbed at room temperature for several hours until all chemical action has ceased. More hypochlorite solution is then added at frequent intervals until the tissue has been digested. * / For small lungs, such as those of rats and guinea pigs, the frequency of addition of fresh hypochlorite solution and the amount should be such that all lung tissue is digested in approximately 24 hours. For human lungs, unless quantitative recovery of ferruginous bodies is desired, complete di gestion is not necessary. In the case of human lungs, the ferruginous bodies and bare fibers are often associated with a sticky lipidic film adherent to the bottom of the container. The stickiness allows one to pour off all the fluid and undigested lung tissue without loss of the bodies and fibers. Because of the presence NOUSTRIAL HYGICNC roUNOATION or AMERICA.INC 6. of anthracotic pigment, the film usually has a dirty gray color. The film is dissolved by vigorously washing it with a mixture composed of one volume chloroform and -two volumes of approximately 50% ethyl alcohol; the total volume should be the minimal necessary to remove all the film. The wash fluid is centrifuged for about five minutes. Because of their high specific gravity, the ferruginous bodies and the insoluble mineral particles settle to the bottom of the tube. On the other hand, most of the carbonaceous material collects at the interphase between the chloroform and the aqueous alcohol. If too much alcohol is used, the carbonaceous material will lose some of the water that lowers its specific gravity. As a result, there will be no separation between the.anthracotic material and the ferruginous bodies. In such cases, rehydration with water followed by the addition of chloroform will usually effect a good separation. */ All of the fluid and solid material above the sediment at the bottom of the tube are discarded, and the walls of the tube are cleaned of the ad- herent anthracotic material. The sediment is washed several times with water to remove all hypochlorite and other water-soluble materials. It is then stored in an aqueous or alcoholic medium. When smears are made of the suspensions, it may be advisable to dehydrate the smear and use a mounting medium to render much of the mineral dust associated with the ferruginous bodies less conspicuous. The naked fibers remain visible INDUSTRIAL HYGIENE rOUNOATION cr AMERICA.INC 7. In the ease of small animal lungs, chloroform and the supernatant fluid were poured into centrifuge tubes in a proportion of 1:2. After centrifuging, the supernatant fluid was carefully removed and discarded except for about 1 ml left undisturbed on the bottom. The film on the bottom of the original container in which the lung tissue was digested, was then removed as in the case of human lungs. This fluid was added to & pool of whatever sediment was obtained from the supernatant fluid. The subsequent procedure was the same as with human lungs. We have worked with formalin-fixed tissue only, but there appears to be no reason why this method should not work equally well with fresh lung tissue. Results Paraffin -Sections Initially the ferruginous bodies were sought only in paraffin sections that had been stained with hematoxylin, eosin, or Peris' test for iron. Be cause of the paucity and small size of these bodies in the sections, the hema toxylin made the search more difficult. Subsequently, replicate sections that were given the Peris' test only,or also lightly countersjtained with eosin and cleared, proved to be satisfactory. The injected fibers generally were confined to the air spaces where they were associated with free macrophages. Some of the filaments^passed INDUSTRIAL hygiene FOUNDATION OF AMERICA INC 8. through the bodies of one to three, and even four, macrophages so th.Tt these cells appeared to be impaled as though upon a spit (Fig. 3C). When the sections had been stained for iron, the dust-containing areas, under low magnification, were usually marked by a granular deep blue coloration. In sections of lungs of hamsters killed one month after an intratra cheal injection of aluminum silicate and glass fibers, occasional ferruginous bodies were found. These were nbn-segmented, light yellow, structures with bipolar clubbing and a transparent central filament (Figs. 2A, 3A). These, subsequent to the Peris' test, took on a deep blue color that often obscured the central filament. Very similar non-segmented bodies were seen in suspensions of isolated and concentrated human asbestos bodies derived from an asbestotic lung of a worker known to have been exposed to chrysotile asbestos dust for 30 years (Fig. 1). The ferruginous bodies that formed in response to chrysotile asbestos were smaller than those that formed in response to aluminum silicate and glass and also different from the latter two in being segmented (Fig. 4C). The ferruginous bodies were more readily found in the lung sections of hamsters injected with aluminum silicate filaments than in lung sections of animals injected with filamentous glass or chrysotile dust. No ferruginous bodies were found in the lung sections of hamsters injected with silicon carbide--------------filaments at this time (one month post-injection). INOUSTmAU HYGIENE fOUNDATION Or AMERICA.INC 9. Examination of lung sections of hamsters killed six months after the intratracheal injection of the filamentous dusts revealed no more ferruginous bodies than those encountered five months earlier. No segmented forms were found except in association with chrysotilc dust. No ferruginous bodies were seen in lung sections of hamsters injected with silicon carbide. Dust- containing alveoli found in sections of lung from a hamster injected with talc were easily identified because of the blue coloration caused by the presence of iron; however, ferruginous bodies could not be identified. Similarly, no ferruginous bodies were found in lung sections from hamsters injected intra- tracheally with attapulgite. Lung Digests * The smears of the sediment derived from the digestion of the lungs from hamsters injected six months previously with aluminum silicate, glass, and chrysotile, respectively, consisted largely of naked filaments, but many ferruginous bodies were also seen. Although most of the ferruginous bodies 4 that had formed in response to aluminum silicate and glass fibers were non- segmented, a number of segmented forms were also found (Figs. 2B, C, D; 3B, C, D). A more prolonged search of the sediment from lungs of hamsters injected with silicon carbide was necessary before several ferruginous bodies could be found. Tlis search was facilitated by applying Peris' test for iron to the smear. The bodies were mostly nonsegmented, and except for the clubbed ends, the coating on the filaments was thin. One silicon carbide . fiber was found with a club-shaped coating at one end, a fusiform coating near industrial mygicnc foundation or America inc .10 the other end, and a very slight thickening near the middle (Fig.4A). Two segmented ferruginous bodies that had formed around silicon carbide fibers were observed. Unfortunately, the diffusion of the blue pigment of the body rendered its outline fuzzy (Fig.4B). The sediment from a lung from a hamster injected with talc was com posed largely of crystalline plates; but upon careful search, a number of nonsegmented ferruginous bodies were also found. These too had a transparent central filament. (Fig. 2A, 3A) Because the Prussian blue reaction for iron had also been used in this smear, the outlines of these bodies were fuzzy because of the diffusion of the pigment (Fig. 4C). Unexpectedly, ferruginous bodies were more difficult to find in lung sections after chrysotile, than after aluminum silicate injections* The same finding was observed with the concentration method. Although few in number, all asbestos bodies were segmented (Fig. 4D). Or.e of the most interesting observations was that, when stained for iron, filaments that passed through the bodies of one or more macrophages showed a coating of ferritin or ferritin-like material only on the intracellular portions of the filament (Fig. 3C). The sediments from the lungs of hamsters injected with attapulgilc revealed no ferruginous bodies. ' The failure to find ferruginous bodies in these sediments may be interpreted as a negative control to indicate that our positive findings were not attributable to the accidental inhalation of fibers in the ambient laboratory air. industrial hygiene rouNOATiON or America inc 11. The sediment from the human asbcslotic lung was a rusty, red-brown color; in the smear, a wide variety of asbestos bodies were seen in addition to innumerable naked fibers. As previously indicated, a large number of the asbestos bodies were pale, thin, and nonsegmented. Also of interest, was the fact that many of the largest bodies did not have smooth surfaces, but were spiculated. The spicules were often coarse and had squared-off ends. A few of the bodies lacked symmetry. Some pear-shaped bodies without a central filament were also seen. Although most of the bodies were more or less rectilinear, many curvilinear forms were also present. Some of the latter appeared to measure between 180 to 270 degrees of arc. In the larger spiculated forms, the central fiber was often obscured by the thick, dense, red-brown coating. Some of the very long thin fibers (50 to 100 p.) often had segments of ferro-protcin at either end with relatively long stretches of naked fiber in between. In an attempt to free asbestos bodies from adherent fine carbon -- particles present in an otherwise "clean" suspension, it was subjected to ultrasonic vibrations for a few seconds. Unexpectedly, only naked fibers remained, and no asbestos bodies could be found in the suspending fluid. Comments __________ ___________ Because bodies similar to, or identical with, asbestos bodies have been found in human lungs about which definitive knowledge of the identity INOUSTRIAc HYGIENE FOUNDATION OF AMERICA INC li. of-the central fiber is lacking, the generic designation of ferr ..inous body has been proposed to cover both asbestos and so-called pseudo-asbestos Q bodies. The distinction heretofore made between asbestos bodies and pseudo-asbestos bodies may have been based in part on what the observer believed to be an appearance consistent or inconsistent with that of asbestos bodies. More often, however, this distinction was based on the observer's knowledge that the host had or had not been exposed to respirable asbestos fibers. Consequently, it would probably be correct to say that the crucial point of difference between a diagnosis of an asbestos body and one of a pseudo-asbestos body is the observer's knowledge, from the case history, of whether the central fiber could be an asbestos fiber or not. Regardless of the nature of the central fiber, the bodies that result in response to the presence of filamentous dust in the lung have as a common feature a coating of iron-containing protein (ferritin or ferritin-like). Furthermore, it appears probable from a study of the pleomorphism of human asbestos bodies, which was so well illustrated by Gloync and Mcrcwether, ^ that differences in size, segmentation, or other morphologic features of the ferruginous coating would not serve to distinguish be'tween ferruginous bodies of asbestotic origin and those of non-asbestotic origin. Thomson has proposed to differentiate ferruginous bodies into asbestotic and non-asbestotic ones on the basis of the transparency or opacity INDUSTRIAL. HYGIENE FOUNDATION of AMERICA.INC 13. of the central fiber. ^ This proposal seems inappropriate inasmuch as we have demonstrated that a number of transparent fibers of respirable size other than asbestos are capable of producing ferruginous bodies that are indistinguishable from those produced by asbestos. At any rate, it is obvious from the production of ferruginous bodies in hamsters in response to respirable, colorless, transparent filaments of aluminum silicate, glass, and silicon carbide, that such bodies represent a general reaction to filamentous particles and are not a specific reaction to asbestos fibers. To what extent our findings may have application to the ferruginous bodies that are being found with increasing prevalence in human lungs 1-4 remains to be determined. The applicability depends, of course, upon the identity of the central fiber in the ferruginous bodies. The method f of isolation and concentration of uncoated fibers and ferruginous bodies from human lungs described in this paper may help in the study of the nature, identity and prevalence of inhaled filamentous particles and associated pul monary ferruginous bodies. It is highly probable that the composition of the ferruginous body is altered by the method used for isolating them, since it is not likely that - --with the destruction of proteins leading to the liquefaction of all tissue elements in the lung, the protein in the ferruginous bodies should be spared. In all likelihood, the protein constituent of the bodies is destroyed and only the iron INDUSTRIAL MTGICNC FOUNDATION OT AMCRICA.INC 1 and other inorganic components remain to retain and maintain the form of the bodies. The fragility of this chemically altered ferruginous coaling is indicated by the ease with which it is removed when subjected to ultra sonic vibrations, thereby rendering the central fiber naked. This may further facilitate the identification of these fibers. There appears an increasing tendency to consider all filamentous dusts in the same category as asbestos with regard to their pathogenic potential. This reasoning is probably based on a mechanistic concept of the pathogenicity of fibrous dust in general and asbestos dust in particular. Such a mechanistic concept holds that the pulmonary fibrosis in asbestosis is the tissue response to mechanical trauma produced when pulmonary cells are perforated or impaled by the fine points of the asbestos fibers. ' It need only be recalled that a similar mechanistic concept of the pathogenicity of crystalline silica was abandoned many years ago because of overwhelming evidence against its validity. Just as the proven biologic "inertness" of diamond dust was the coup de grace for the mechanistic pathogenetic concept of silicosis, 10 s' o should the proven biologic "inertness" of filamentous aluminum silicate^ have done the same for the mechanistic pathogenetic concept of asbestosis. Extremely thin flakes of glass may also be considered to have sharp cutting edges; yet, this has also been found biologically "inert" when inhaled * or injected into the lungs of animals. Silicon carbide, noted for its hardness INDUSTRIAL HYCICNC FOUNDATION or AMERICA INC 15. as well as sharp edges and points that make it such an ideal abrasive, when inhaled as a fine dust or injected intratrachcally, has resulted in a pulmonary response likewise classified as biologically "inert. Gaining increased attention is a newer concept that the potential of extraneous trace metals and other materials associated with fibrous minerals can cause the injury previously attributed to fibers. The respirable fibers may provide a transport mechanism for dosing tissues with injurious materials associated with the fibers. Cralley et al., ^ have shown that asbestos textile workers in the past have been exposed to appreciable concentrations of nickel, chromium and manganese associated with the fibrous mineral and abraded .> * from the alloy metal in asbestos processing equipment. They state further that there is evidence that this phenomenon exists in relation to a number of other fibrous minerals. There is also some indication that the biological response in the formation of ferruginous bodies may be related to the nature and extent of the layer of metal solute surrounding the fiber. Additional research needed in these areas is currently underway. Unless the above facts are kept in mind, the finding that ferruginous bodies are formed in response to aluminum silicate, silicon carbide, and glass filaments in the lungs, may be used as still another reason for erroneously classifying these dusts with asbestos in their ability to'produce lung damage.-.--- industrial mycicnc rnuNOAT.ON or amcrica.inc 16. Summa ry The mechanistic theory of pathogenicity of dusts, which in the ease of silicosis long ago proved groundless, nevertheless has again been raised with regard to fibrous dusts such as asbestos. Reasons arc given why the formation of ferruginous bodies should not be confused with pathogenicity. Failure to understand this differentiation has resulted in some instances in the erroneous generalization that all fibrous dusts share the ability of asbestos to produce lung damage. Such inert materials as fibrous aluminum silicate, silicon carbide whiskers, and fibrous glass produce ferruginous bodies experimentally which are indistinguishable from those produced by asbestos fibers.Details of a method of illation and concentration of ferruginous bodies from lungs of animals and humans are described. With this new * ~i . technique, much more extensive studies of ferruginous bodies found in the lungs of asbestos workers with definite asbestosis (fibrosis of the lungs) have been made possible. Ferruginous bodies from asbestos fibers are much more pleomorphic than has been described, casting further doubt on morphological distinctions used in the past in separating so-called asbestos bodies from pseudoasbestos bodies. Attempts to identify central cores of ferruginous bodies by analytical means such as electron diffraction and microprobe techniques are underway. INDUSTRIAL HYOICNE foundation or AMERICA.INC REFERENCES 17 1. Thomson, J. G.; Kaschula, R. O. C.; and MacDonald, R. R..: Asbestos as a Modern Urban Hazard, S Afr Med J _37: 77-81, 1963. 2. Thomson, J.G. and Graves, W.M.: Asbestos as an Urban Air Contaminant Arch Path 8^:458-464, 1966. 3. Cauna, D.; Totten, R. S.; and Gross, P.: Asbestos Bodies in Human Lungs at Autopsy, JAMA 192 :371-373, 1965. 4. Anjilvel, L. and Thurlbeck, W.M.: The Incidence of Asbestos Bodies in the Lungs at Random Necropsies in Montreal, Can Med Assn J 95:1179-1182, 1966. 5. Davis, J.M.G.: Electron-Microscope Studies of As'oestosis '.n Man and Animals, Ann N. Y. Acad Sci 132 ; 98-111, 1965. 6. Collet, A.: personal communication. 7. Cralley, L. J.; Keenan, R. G.; Lynch, J. R.: Exposure to Metals in the Manufacture of Asbestos Textile Prodxicts. Presented at Annual Meeting of American Industrial Hygiene Conference, Chicago, May 1967. JAIHA, to be published. 8. Gross, P.; Cralley, L. J.; and deTreville, R.T. P.: "Asbestos" Bodies: Their Nonspccificity,' JAIHA," to be published.------------ 1 9. Gloyne, S. R. and Mcrewether, E.R. A.: "Asbestos", International Labour Office Supplement, January, 1938, p. 7. INDUSTRIAL HYGIENE TOUN^ATION L F AMERICA.INC 18. 10. King, E. J.: Yoganathan, M.; and Nagelschmidt, G. : The Effect oi Diamond Dust Alone and Mixed will) Quartz on the Lungs Of Rats, Brit J Ind Med 1_5_: 92-95. 1958. 11. Gross, P.; Westrick, M. L.; Schrcnk, H. H. ; and McNerney, J.M. : The Effect of a Synthetic Ceramic Fiber Dust upon the Lungs of Rats, AMA Arch Indust Health 1_3_: 161-166, 1956. 12. Gardner, L.U. : Studies on the Relation of Mineral Dusts to Tuberculosis, Part Q. The Relatively Early Lesions in Experimental Pneu moconiosis Produced by Carborundum Inhalation and Their Influence on Tuberculosis, Am Rev Tuberc 7:344, 1923. 13. Gross, P.; Westrick, M. L.; and McNerney, J.M. : Experimental Tuberculopneumoconiosis, AM A Arch Indust Health 19: 320-3-34, 1959.  4 f 20. *r industrial mygiEnC foundation or amcwica.inc 21. J-ciiowls of Illustrations Fig. 1 Asbestos bodies from the lung of an asbestos worker to illustrate some of the more simple forms that may be found. In addition to some apparently naked fibers, there are pale, nonsegmented, rodlike bodies with bipolar clubbing. The dust was probably chrysotilc. Concentration method. Smear. Unstained. X 1100 Fig. 2 Ferruginous bodies formed in response to the intrapulmonary presence of aluminum silicate filaments in a hamster killed five months after an intratracheal injection of 3. 5 mg. of the dust. These are pale yellow to golden in color and transparent. The central filament is visualized with difficulty because the index of refraction of the mounting medium on the slide is close to that of the filament.* 'This can be appreciated in D where a naked filament about 1 p in diameter traverses the approximate middle of the field, and a 3-p thick fiber cuts across the right lower corner. Concentration method. Unstained smear. X 1100 Fig. 3 Ferruginous bodies formed in response to the presence of filamentous glass dust in a hamster killed five months after an intratracheal injection of 3. 5 mg. of such dust. These bodies appear to be very similar to the more simple asbestos INDUSTRIAL HTCICNC rOUNOATION or AMERICA.INC 22. Fig. 4 bodies pictured in Fig. 1. Bodies in A, B, and D arc unstained and arc found in a smear of sediment obtained by the concentration method. The ferruginous body in C is from a section of lung from the same animal. The section was stained for iron, but is otherwise unstained. Four macrophages are faintly outlines. Their cytoplasm incorporates portions of a glass filament. Only the intracellular portions of the filament are coated with iron. X 1100 Ferruginous bodies formed in response to other filamentous dusts in the lungs of hamsters. A, B, and C are from smears of sediment obtained by the concentration method and s* tained for iron (Peris' test). The central fiber in A and B is silicon carbide; and in C, tremolite (talc). The - */ body in A shows a clublike thick coating of iron at the lower end, a fusiform coating near the upper end, and a slight swelling near the middle. A blue coloration of the surface t of the fiber extends throughout its entire length. The body in B is segmented, but is fuzzy because of diffusion of the Prussian blue color. The other two fibers in B are uncoatcd. A similar fuzziness is seen in the tremolite ferruginous body in C for the same reason. The ferruginous body'in D has a chrysotile fiber in its center. This is from a stained section of hamster lung. X 1100