Document gakGdM94pVLmJd8O7mKDK2j9q

PLAINTIFF^. exhibit" DOW-348 /j /C-sav-fi Cm*** ( PatmoMf7 aca Srr- R. Nfc oot*. P. Cauu*BUttx> % and P. La. Bui. . (*Natl. TubtrailoH Li OCTOBER 1969 VOLUME 100 NUMBER 4 AMERICAN REVIEW OF jP --y y ^ RESPIRATORY DISEASE Clinics! snd Lsiors/ory Studies *j Tn&trailctu snd Rtiptrsisrj Ditssts STOOI1657 ASBESTOS AND HEALTH IN 19691* ftEORGE W. WRIGHT Although a group of materials referred to troerieally by the term "asbestos" have been known and used, to a snail extent, far back in antiquity, widespread and abundant use of these fibers did not begin until the last quarter of the nineteenth century, with further augmen tation of production during the first half of the twentieth century. There are six distinct varieties >f asbestiform fibrous minerals. Among some of ihwe, there are striking differences in chemical and physical composition (1). Most commonly iwoduccd is chrysolite, a member of the serpcntine family. The amphiboles are subdivided mu crocidolite (blue asbestos), amosite, anthophyllite, tremolite, and aetinolite. All are silicates, crystalline in nature, and characteris tically are divisible into very snail fibrils. Chrysolite and aatbophyllite contain much brger amounts of magnesium than either voeidolite or amosite, and the last two contain much more iron than the others. The crystalline 'tnieture and surface properties, which may be of importance in the biologic reaction, are also 'rikingly different among the varieties of aJxstoe (1). In view of the great variation of rixenieal and physical properties, it is most un ite to predict that the biologic reaetioni of one 'arn-ty of aabestos will be mimicked by another m terms of cither actual consequences or meehouisma. To interpret the biologic actions of 11'icm the Department of Medidae, St. Luke's "`wiital. Cleveland. Ohio. * Presented before the Medical Scsuon, as part "f Section 3A, at the annual meeting of the Ameri ca Tliuraac Society, Miami Beach, Florida, May 53.196*. asbestos, it is imperativs that the character of the exposure in terms of concentration, rise, snd types of fibers be known. This sort of data is aeaat or often nonexistent at present with respect to exposure of humans. Pulmonary fbradc: In 1907, Murray (2) re ported the first cases of diffuse pulmonary* fibrosis discovered among a group of persona who had experienced substantial and prolonged exposure to respirable-eised asbestifonn fibers. Subsequently, the term "asbestosis" was applied to this reaction. Traditionally, asbestou baa connoted this kind of reaction and its sequelae with regard to altered pulmonary and cardio vascular function. Recently, the term has been corrupted to include such manifestations u pleural thickening, pleural plaques, and even the simple presence of ferruginous bodies. Resolution of the use of the word asbestosis must be ob tained to bring elarity to scientific reporting. Murray's report revealed the paradox of a life saving agent poseeasing the capacity for human harm. At first, the conditions under which this biologic reaction came about seemed to be re stricted to those created during fabrication, conditions limited to textile manufacturing at that time. In 1930, Merewether and Price (3) demonstrated that asbestosis posed a major threat to the health of workers in the asbeatoa textile trade. It is now known that in any of tbs several trades in which persons experience pro longed exposure to a high concentration of respirable-eised asbestiform fiber, it is probable that aoihe of them ultimately will develop pulmonary fibrosis. In response to the report of Merewether and Aucmcan Rcvibw or I?ssrm.\TO*T Disease. Volume 100. 1969 467 DOW 0694 of tha with popafctba in to time of tba-Udted S T 0 0 I1658 (onhfliM4 tba itkttmxvMMtoit tba faetocka, adht>-' ud i nbapart la tad h ** oenpitM of World War O. (>. WHTl^wd It the prrrrntiua if' eaa vntd ooadadt Id tkMUV ad thMa art flat far tbt aafa an af rudhd to-protart afl fibera. Aa a raaaft, the proMrtfca ad at preaaat, aad Ha dmkpmuat id ' worta* mmg aabartoa ia maiag aad Mflb( ergaat tadci of the tandkta fatara;; aad aqiaeiaOjr ia factory aattiafi haa act beta aa laa, aa important atap hta bw rood aa it arithtotbmrin hart baa. farther ddWaf Um coadUkaa Uatfl qaito awady, tba thraboU Had! prrftioa aad okfcaata at ndoa -(TLV) for iimroimurita toetakiag aa pahairy fibrode-ia OmvTQRI DOQV9mQ TCBC1U*C1/ Uy oi/WV MMmT and Drama (4) ia 1909 haa aamd aa a frida. Data aadrdjr adaqaata for tha parpoaa am aat irdaMi 1909, aad H haa tafcaa yaan to raaaf aba tbla 1--rlafiy aad la obtain tha inform tha apea which to boaaa port a>wninqfd TLV. graaebopafc eaacar: Lywh md takh (10) r>w m hi j otfl IMTthot tba bMopa Maaaea of 1 AlthoatffV rortaaatdjr. n of tho Major naan of adroa ^ Miwnthr (It) t ia tba prodaaooa of textilaa aad tertfla prodorta brntinpoit aaaaar at 11 par 1 haa punaad far may joan a progriM af #> of pmem who had aabaaloato iromental aad population BioaitoriBf that piqynaat ia tba --tftt trade.' ae^ pi^kfaa a mow ap-t<hto aapariaaoa DoQ (13) raportoda (^ 0)* Thaw Madha drraonatrata that (nba^ of tea tbaae tba aspoahd tala la1 nary fibwaia eao ba bmintbad when adequate tzpoaad for at laaat 90 nan, < ptataadra maamaa art hatitotad, and that tba betaaaaJOBaad llg.Tlh< moroninboa o.f<ah6borawa fiba.n a*nd batba o>odhmd I^n thoSmtSfla5troTdaw;_ aad wxjmmr* Tht U. 8. FubbaHeahh Serrfc^ vhieh befu ertaarre ataaa arto tba prnhl-- faabaBaa aad boabb la 1961,* together with >*xatoa prodoeefa aad taajwtaetoma ia tba (Ml. .irf Gtadt m u IM. ita. M| emrtarr (16) tnportad a fnqam rhaimk-------- -TpUm TLSSm^ZSn non ii ^~Tf T^TaI * r~~nid rnwanfnllna ev beehtiow, that ii DOW 06941 AltB MUITM IX 4*1 on n|wuc m pan 30 year*. h w tbnr Hwln. red Kingdom. \ raamintin uf rrtn neuri i ihai arlm-furm fil ere (i,r ,0 iimlniraiini il tole in the augmented ,,,^rmry of hrimetegrair raarrr in mrae cam of oarlat. la nuna of there categories, Si^iorr, haa there been a fufl expraitiuo of other |r<ooi ex|ius*'l for JO or murv yrsra. Thia mdiram a heavy and pmlmignl c.\j*nrr to arlmttn fra three tan ty|m of worker. Kan and *wriatrs (5), in a runtnmatiim ul the study of textile workers previously rqnriri by JJoMCO hu been set r* doiamra whirfc rersvt with aahrataa in the (13), ebutr that the inrwinire nf King canrefi sad A slightly do .Minaaat and to which the worker haa been dwittim with prugrewivriy smaller total et* jM is the U> ntNiIl Tarietm wfcirh haaa n- ,Mwod (fife d, 17. IS). It M pooihle, therefore, tut rorawting amteriala pn at wing eareino{Her potential aught be implicated. It wooid be pamirra to asbestos fiber*. Xnrhorae (13), m an wteastm textile population, hat shown that the uetaneoee of puhtmaary eaneor differ*^ ble. Thera is era t4ialrat to explore tie pusability thoroughly markedly with total isputter. She fepuns nocn t that chryrai Mdt erupting sshreto* per m as the rare** mcrewa of tha iacbteaee of hmarhnpiasr *Q iai me larwr. eaanr in a law to moderately ispowd graapw- more noddy tba. la mbretra (astir milk, the expaeara arrolvm wheeraa m a heavily expand graap the taw(S). Ain, chrym l<--riK twa varietiee of asbestos, ehryeotile and deara waa augmented eightfold. Both graapor mk is experimcets riwrinlit*. la mrae factories oi haa barn were from the mate textile mill end were smritera. bhfc (9). il<t4wd to the fiber* before final prat taring, with respect to duration of expoaira raid tho^ tioa air pobnrara.i Manarm, m the jwoeaw of "opening" the hagth of tbnr of olwervation. EnuiDat end^ h 1999 that a (dm, a atrang pradbility rants that traeea Readrirk (14) deraonetrated a stronger nh ilm hart not bra a owtsb known to have carrinegerar ia- tnariap between hiog cancer and traptoyMM* nlations that hen Ihrnre* may have been added to the fiber* in the arbeotoa textile trade than exht* in the aO. The kaawlcdp jl9-21),, ha dusty manufacturing of a*beetoa bufldbqr era < aotavaMt 'V fraoBtiaa workers have been exposed not pradnela or building material*. In a serieeet te * of * wdy la ebrymtie ami smarito but aim, cope* studies* Maocum and EUAttar (18) sdffiNIdi*- e .ora. XeTettte vXy hi shipyards, < cidolxte. The natura that eaneer rid it lower with lemar etpraarao brra taken towed 4 their work, as the. c move old bwulation and to asbestos. From these observations, the - mratnrr for th apply new in various placet, espouse them femes etrongly favors a do*e rriationriup be- Jition of rigoificsr vnriirrs to many nonaabratae rafastanera, aoma tween bronebogenie eaneer and whatever effect DM exposed to a 4 whirh miy he hydrocarbon* adsorbed onto asbestoa fiber* may ultimately be shown to have 'he arivwtt* fiber. The rxpnwre history of in* in it* causation. Althoegh in 1* "ibtaoe workers is seriously hekiag as to specific The question of whether the caretnograrir srtrd brentboy* Irsib of aO of the materials that they may rate of asbestos ia related to the specific kind nf itniiine'a, it m a* fora inhaled in addition to asbertos. fiber is more difficult to answer. For this par* Uity of tfaia aecra <>f the numerous questions which rouJd be pose, populations having longterm exposure-Co fiber was aenoad (rad concerning the relationship of ariawtoa only one varisty of fiber art needed. Virtue^ (11) demonetise1 awl hrnnehogsnie eaneer, the fodowing three all fabricating proce--m use more thsn ohe- mt rent of autopm *" *f immwiiate pnetleal unportanw: (f) Is variety within the same premises at any tara- ariring from re 'fo mftuenra dose related? (f) la it related to tlmo or hara used more than on* variety at le. Eight yean law 'jriny of asbasios? (5) Doss the reiatiorahtp various timea. Populations restricted to miaing- nry el hiag nan v4v* eocartinogvrtesii? Some evidence bear* and miffing In the production of asbestoe flser ite in textile work* * j'00 quartuna ia now available, but lend tbemaelvm beet to a study of tbs (foots rs, during the peri* ""wmstanra is it complete. of a single kind of fiber, and it is to draw a experience haa ha I*/* eoneerniog the question of dose rate* populations that ope must took for an anmreeto ir by Xewfcooee (1* 'stdilpo do exist. The type of work ratetad the influence of a single variety of fiber. (14), and Manrw ** rtrongly to the devriopmeot of broneho- Xhrfluoto and Mrunmo (33) ritowed that recriitly, Sefikoff i rr !"*** in tb tite and tha exposure during tha praduethm of anthophyi. a frequency of bn* "V0" *PP*teationa trades; the worker, ta fite in Finland earrira with H a threefold to a that anticipated' t motaaeas, has been employed ia cither fivefold increased risk of bronchogenic cancer a employed f> for 30 or more years. Merewether and for thorn fat the age group older then 48 yearn jrd a mhetaan w, ad Britkoff and amoriatra (31) ra- with more than 10 yearn of exposure. At this >ring old or apphr* *." of mbostorie (pubnonary dam, thera are ae pabllsbed iteu with respect aincd aabeatra. D "*1 m these croups of 80 per cent among to the frequency of bronchogenic eaneer in the DOW 06942 * l 470 r.i ^w.'wwmrr*- t croridofcte nr ammmU predoctrao in of faith Afnra, the only pkre in the wrid whew prerialde asnonwta of tlraselvpes o( fihrr ere predueed. A verbal report* (ran fatth Africa mibhu thet the fregasasy somewhat hitler than anticipated ia the pwenl popuktfam of thet coamry. Debt from three regwae will tie waited with great iaterret. fa 1958, Bnua and Trim (23) reported a etady of the frequency el lung renter in waste* of the aiinra tad milk producing-only-draysotik ia the ceeteia pert of Quebec, Cicada. from the deu anil* abk to them at that lima, they found ao evidence The considerable variation ui tlsc bnj wi ftieskits ineidcsMt between popuktinm of u> many years. feeing typre of empfoyment- may he m4 etsSerii Tims. ftrekiod to dosage, but it may also Ira the ns* *.w ami rkt of differing eorareinogena. Grom and awetu, Invretknu (36) produced a higher than anticipated If. liateexeuMW qoenry of pulmonary eanoer ia rate exjewd <. 4ad the Irrep chrysolite. They attributed thk variance. In/ terns ecnqra the experience of others, to ho related to t hr mad* ummation of the ehryeotik fibers by nicb I CO ' cobalt, and chromium caused by the w*r. I the metal components of the mSl used fat pi t paring the fiber for admmistratioo to their t&( be o o of aa augmented frequency of brenthogrera raak. CreOey aad asaoeiates (19,30) showed id , theCW -- rearer in thk creep of employee*. AHhongh the period of olrasrrslraa wan oahr Are rears and the creep was dihrtrd by short-term repreurre, it contained more than 1,700 persona employed tantial amoonts of these trace metals in d itetl! asbestos fibers need commercially. Miller aad s I soeietse (27) have shown that henso (a) pyre I mihap pbm asbestos augments the yield of pul* ' 122), o> O tager then 20 yen% all of whom had hod at aeix tumors produced by beuao (a) pyre-' silMgjjiNr least Are years of exposure sod 930 of whoea afoue. Haringtoa and aseoriatce (2S) raixxl ' thnreqifMp' h were older than 55 yean of see. The data would paarabiBty thet edaorbed hydrocarbons oerw have 1eo more meaaiagM if arranged in terms ring natively or pieked up in storage sr td of total rxpawre and time from lx*inning of ex* handling may play a role ia eocareinogrorek lart fee pomire. NevertWere, if ra exrewi of King eaoerr As reviewed ia 1909, the role of asbestw t li___ ..r __ equivalent to that sera a the retimes referred aogaenting the ineidenee of broochogcoie re { si sktte.wt to previously in this paper did aetnalty exist eer appear* to be dose-related, may be depetsk stth festfle : in this popuktioa, H seems likely it wooId opon the specific category of fiber, peekByrrot study o have bren found. This amt imputation is now relation to the degree of effect, and appear* w (tends w. being revuslkd sfter a much longer period of he that of a eocarciaogen. to meat v observation and in a more adequate way. .Vexxkelioma,: Subsequent to t)ie carlirr t { bra hoemtfs Vigtiani and svorntee (24) have found evi dence of an augmented frequency of earner of the lung and pleura m a group of 289 persons, previously compensated for asbestos* arising from all omipatwna, who died between 1943 and 1M7. In a subgroup of 32 miners exposed to rliryaotile only, there eras no augmentation f ihe rate ef esnrer of hint and pleura. Al though there studies suggest that ehrywrtile has little or no carcinogenic influence, more ex tensive and refined epidemiologic data ate neeihal before reaching that conclusion. The pmailolity that the carcinogenic role of asbestos is solely that of a cocaretnngen is very strong. The data of Sriikoff and arenektes (25) .are cs|*cially pertinent in this regard, in that not a single bronchogenic cancer has been found in an insulation worker who was a nonets*ret tr smoker, even though Ilie exposure tit a-lsYto* experienced by the nonemokeni waa the same as that of tksra who smoked and did' develop lung eanrer. ports linking occupational exposure to sabre at ridti wltli aad bronchogenic cancer, there were sugg*eiiune thet tumors of the peritnnml r rkre ,of<wt pleural iaesothcfium might be similarly Irak Interest in this phenomenon remained dona* however, until Wagner (39), in 1959, repra- 80 tun of pleural mesothelioma aamekted * the Northwirat Cape region of South Africa. I suggested that these were related to cxiumii* crocidoliu aabeetoa bemuse 14 of the * *d HU were bom or had spent their early youth *> ' `fo"* Ktiruman, where croridofite productran k of the major industries. Thk obscrvi prompted an intensive search for all ns-*" liomas in South Africa. Gilson (30) plotwd ' numher and distribution of the faith cum up to 1902 and demonstrated a *"1 ennerntretion of cares in the Northwest *' ' Although almost none waa found to * elate Irate in faith Africa, the informer it"'' concentration of inreothrlinmee eoinreW the sole source of erocidnlite in fauh * fl'detif, I.: Prrenoal communication. wwld not be warranted. A siihstantmi r*r t DOW 06943 AXD nkalth IX It 471 tkm te the h- ,4 rfucnUile ha* been prudaeed for a period of It b apparent that the overwhelming fipulaliens of 4 aiiay year*, knadwds-of mites away te the caam liras tar being related to asbestos art mt may be ML . ,,irfa Traaaraaf, the aaoie area te which ai rfiagnrwsd on tha bates of biopsy alont. Farther ty aim be the r** han aatkipatH fc w in rata opaH' this emriaarac fie and rhrymtde aterttao are produced (31). tamtigataes te other parte of the .jf foateed the dirtributioa of .ad the Irrqoeoey of moothefioi *.. aerupoliaBSity exposed to aahntfle, with stndy wiH be needed to demonstrate whether CO mcmtteiinma is being ever or under diagnoeod. --t If ene aecepts that come kind of direct or O tetunt retetmmhip between tebeetoe end o memihilisma erica, docs it involve a epaeifia 9 be related te m ii> mult that a strong rdstkoteup betweeo ontie fiber*-by aiti ,.Mire to tebetem fiber aad the preamco of ard by the wear arwtbefiomo hoe been mdketed. Meet of the variety of finer? The data from the U. aad United Kmgdoasdoee not hod itself to remfria^ tha.qomteon beeaum chrysolite, smoteta, aad. CT cn he nl mad la pr n oetside Sooth Africa, where amtec aad are weonrad tae msuMuaa workers' tratioa te their nulling are anpfieated, hare baea reported te aad ehryaotik pteo eroeidolite ia that (19, 30) showedM tr I'nited Kingdom aad, ta a teaer dogro% ia of the testate manufseturing employees. If ooe trim metab ia e far UjJ. la epiw of a tboreogh March, ao txamteas the mtemg and milling expomrea ta malfj. MSlar sad i util linen** hare been found awoctetod with tha specific variety ol fiber, interesting facte hat beaae (a) ppr isthophyflhe eaheetoe production in Ftekad (merge. Khrihwto and Meurman (22) did aot- he paid of pete and few ere reported te France (32), fiad a etegh Deaotbetioma ia a large popula f beaaa (a) pjie- Irro the eobjeet has probably not been tion of auaen aad mill workers exposed only ta iatr* (28) raked r bwooghly inrcsbpted. In the United aatbopbyllite. Thia group worked for threw h-dreearbona eat tot, the aamriatiea hae beta with months or mora between the period of 1935 te Horace * i mwletioo worker* end asbortoo textile aad 1M7. Although others have stremtd the i. xarrinogaww urtnrinc faetoriee (331. Ia the US, the rrie* long period of lime required for mosothelio-- e role of asbest* 'Mimbip hae been shown predominantly with dereiopmeut, oat would think that if anthopfayf* of bronchogenic r/ ubtion woriten (10) and, to a baser decree, life by itsrif ie implicated, it leeet oao earn ed, may be depend *i*h textile manufacturing employees (15). Re* would have been found by* now ia n setting of fiber, esperalh si itndy of the dietribution of tneeothelioinai known to reuse asbestoris and a somewhat aug dTect, and appean' n * Ji*da wiO be commented apon later. mented frequency of bronchogenic eeaeor. Ia a In moot of the etudiee to date, the queetieo tody of tho distribution of memthetiomai in sit to the eariier * *>* hem nked aa to whether the population Canada, McDonald and eo-workers (35) were npotoR to tke1 " ndt with respect to meeotbeliooMi ie to be unable to show utas frequency in the geo* there were eo? ' ttsl outeidr well ae inride the factory or graphie arm where ehrysotile, but no other f the peritoneal r slice of work. There has been a plethora of variety of aeboetoo, is produced. I be nmihrly fiat' ( t**wLiiian by atodenta of the problem that The Bouth African dietribution of msootbc m mnatead done* hae hern accepted a* fact or interpreted ae , liooteo h umaually iatoreeting. Webster (II) 9), in 1*50, rrjx - a h |,v lay writer*. Them dramatic speruiatiooi reports that bafore the cad of 1905, 1T9 eaaea dioma associated ` further compounded an already difficult of mesothelioaa were agreed upon as meeting a of South Africa : -.iticr for thorn responsible for public pmtee* acceptable criteria. Of these, the hbtory of ex* related to expM * w aa wed aa thorn responsible for the health poeert was knows te 148 patient*, sad te 24 e 14 of the pee* cm[il<jyr*. Contrormial or pamdoxie iasues there was no aebmtoo expaeure. Fifty-oot po* heir early ymuh 1 He production ` a. Thia ohaen'i* aarh for all ns--' Sann (30) ptottel' * the Sooth A<r *trated a etn: Nocthwtwt <' ass found to e ihe infartnee tHs* annua Hit* te 8n*th .V i cnhatantial **' nicwitlidioma and asbestos deaervr a * rtnp|(tf dtseuwwn than is pwililr in thia *l`r. Among the controversial feature* about rditionahip of asbestos exjnsure to mean "'terns of the pleura and peritoneum are the T,"*C is a livHjr conirmrnry amoon pntholo* ' ictaniing the reipiireinniu for eatabliah.1 'Ittfnnsis of printsr>- mesothelioma (34). - 'aily -m time a question with reapeet In / ,H*1l,*'c rriterri, lait even more important, for establishing by aatopay "tee the tumor k primary or secondary. thnte had born exposed during tho mining and milling of erocidoltt* In the Northwest Cape only. An additional 52 patients with mecoth* liome, not expaced occupationally, weie aa* soeiated in some way with reeideneo in the Northwest Cape. Shifc-Cretniner (31) has indieated that about 30 per cent or all erorWWite (redaction in .South Africa actually come* from mineo brated in the Tratwvaal, a few hundred mites from the Northwest Cape. He aim indi cated that although the exposure mry have bem emnewhat lews tetmse te these mine* than te thow of tha Northwrut Cape, H neverthrleM was DOW 0 6 9 4 4 I 472 1. hath. TV whist's iminirirs cnofirm this and indicate fanherthwi (Hr mtnw of the Trana* rui hare lnri cfwsation far u away yean as ilnoii ikf-Ntinot Capo. The meehanisra- for ohuaMfr-'Arti Rpiffiir inM^MioiHr in ihe TnawkiwrrtJitr arm is iiieMiml to that for the Xerdhrert Capo. Itoauar Ml injrie ease sf --athrKwiis haa been iCaeotired The question of whetlier there a tnlem ^ expuaura oi threshold limit value fur alaw a* l**ti withot contracting an enhanced risk uf k* veloping - mesothelioma has-been raised lor i\ Ori finding-of what, on drat inquiry, seemed fo \s --H minor expusurea to the fiber in nonorcupeti* *. O settings aa a liaclurround for some of the O of mesothelioma reported ia South Africa fo u* from the mcafcSlr aim or surrounding com* imnutir* of thmTmasvaal, although ftl risee ham nae fine the ewekblita mines ud 01 additional-cua^frane the neighboring raiam> nity the-Nsrtbweet Cape pcoAwing exactly and the United Ktrapfam (33). Although r* a- cn mfljr it had been thought that there were ms 4j cr> aueh example*of maaothtliama developing*.?! PO aide an occupation or occupation amociatadva* HmBbwii dvcjw m BWw mnxpfvw QpMMVr in the suar kaad aC fiber, the contention that nlKDVln R^wwS iBv iBn**TM rroridofite per m ramre mrentbefioaie becomes present, 00 per ret or mors of the rntwr U difficult to accept. ffum-Cnemmer (31) poieted Komar that studied in the United in--dili hr* oot thia pandas hi 10*14. Webster (30), in Me and Sooth Africa have been shown to hameir*** eufTPBt report an asbestos exposures in South oecopatfonal or paraoeeupatlonal mocwti ' If <i Africa, Kkrwae eafls attention to thia dwprity. with mbaalm fiber. The level of thia aptfod * It ia of rrpnl intmst that only 1 ean* of ia substantial. Moat easaa occurring oubupfiblMi memthefioaia hare been reported aa original* actaal^oa the job oceupatiooal exposure* awJaw ore mg from the Transvaal, three being front the through-an expoeed worker living on the aalerupati amoaite aabartea mines (311). No cams of pmniarat who brings fiber-mto the home eokfdmbhmfVnBllwn Uil DWV airapaO^unSnmil fIonalVA UIV efetUng, or threucb euntareinatknv of Hlfowho ehrytotile mines of the Tnnaraai. On the haeia environment surrounding an industrial oprrra mm of what ia known about the number of tioa whieb baa mat airborne fiber into illHi am persona employed, the inteneity and dorathin of atmosphere for year* and liras exposed paisa mhmie exposure, plus lapse time, one would expert living or working in such a neighborhood. T> fo far more than 3 easea of mesothelioma if was especially exemplified in the North*'^wre o amoeita had the aame potential aa the factor Cape region of South Africa where roads ehs*ahri causing mesotbeliomaa in the Northwmt Cape. made of aabaatoo-bearing waste rack, wbT The daaage and particle rise have not been women were employed in hand cobbing sr rravpt euffieieatly different in the Northwest Cape gleaning- asbestos fiber from the waste beu-r*l P" and Tranrraal to explain the striking aheence and wfaera the miO disseminated bhw or minimal occurrence of mesuthrliomM in the Transvaal. The discovery of such a striking concentra widely around its location; There-is beliere that them various types of have been substantial in tba population rf hi tion of mesotheliomas in the Northwest Cape involved during the past 40 yaara. Vu' att suggests the need for a thorough study of the With respect to newchborhood or paraoreq- `ra 1 differences between this region and other arena tiona! expamire to aabertae in the US, k *,M- T> of South Africa in terms of pouriMe etiotagie of intercet that Borrow and cworkers l-^Jeai factor*. That something other than, or in ad railed attention to the faet that none of tb^^l dition to, asbestos pbys a role in mesothelioma scrim of mmothrfioma, gletned from a ** *'*4sr i formation seems iaaaeapable. The geningy and munity medieai practice, fell into this rr t'mma elhnate of the Northwest Cape differs con gory of exposure. Hs-ems siderably from that of the-Transvaal. Trace la it meonable to believe that the ewe* " '** * metals, chemicals, nr oils adsorbed onto ashea- mruothdiomx in which no occupational nr r! *** toa may be factors. If eroeidolile is impli omipniiorwl asbestos exposure ran hr -1 Z** cated, K is likely to he in the role of i earrinngm, some additional agent providing the difference between the ex|**rienec of the North west Gipe mid the-Transvaal. Much mors study weeds to be made of this aspect. clanxl, amounting to lem than 20 per m* P, those reported from the United Kmgilraa r'hr South Africa, in fact rrpreaeut a reactw* fUl"' the rasual exposures which might be eUr l r* enced by (he pnblie a^.large? In the IVf* rrt> DOW 06945 STOOI1663 AuMBItM AKB ItKALTH IN 1WD 479- T there a tnlnj *** an.intenwve match (or rent of the population exhiliited them bndies* nit veto lor aW .1.wu has tmi iwrsoed actively daring the These structure* haw Ivco mumtl by many to rvk Ml. .i Mr yean, fearer th u 100 mar* thns far represent mated aalwstn* filwra tml, therefore, ** laen ifterttri in |*raons who have tr**l inquiry* wtd u> ,,l 4 kiv<*a substantial cxpnsnre t asbestos iber in acaormpats* ,.i |( e idik to this* portion of the 132 I far seme of the ra ... staat which there ni no information, i in talk Africa *.[ - mmler of ptooia who have not hod a to indimte .in rx|meurr to the inlislation of at* Iwslos fiber, hence a higher rik of drvetnttiug mesothelioma. Several (nets militate against this conclusion. TV routed fibers fouml in tlie lungs of tV a (33). AMmoth >:' ..orrahle suViantinl wpaurr, hat in whom |sdilie have not lore proved tn he ashrstm l that there were at/) i- -slwtann haa developed, ia lew than 200. fiber*. When they are found in person* who ,,*<> number ia soch a nrinosetde proportion have experienced a heavy exposure to tl*e in rupatha amnristed t*> adult population from whirh the am note complete expnsr hifr become* difficult to en- propnrtiaa creator, mini the view (hat the asbestos fiber* that mom of the the United t,,v he in the air and rmpiwd in a eaaoal ,-tawa by the poMie at large pnee a genome here ahown to hate .rrsmgenir threat. cm If few pnetuiatr* that there are respirable- . level of Una expoe- /-*l filers of aabeetoe in the ambient air m Mihed by the general public, the strikingly ml exposure" m >re errurrenee of mesothelioma not related to firing on the nr rotation atrongfy auggeata that there ia a rr into the home no! 'r.iWr level of airborne ashrrtoa fiber whirh contamination of i not cause an undue riek of development Nt an inda-irial opt r ns-suMkunn. The findings of Xrwhoum tirhoroe fiber imo t: I '! ami MrDunald and amoriatea (35), whieh ad thoa expoaed prr- !>air that a genuine occupational exposure rh a neighborhood. T - aJwdi* has been tolerated witboot eri* ified in the Northv (are of an increased risk of developing a kfrica whom roada w e^sklioma. suggest that the tolerable level halation of asbestos liber, it is reasonable tn omume that tlie bulk of these hodir* do represent asbestos fiber. It haa been shown, however, that other materials whirh are fibruua in nature will produce bodies of an klmtiml appearance (41). Cratley and as sociate* (42) have listed 20 mineral materials that are fibruua in mture and- that may be widely diaacmiiMted in the environment of the general publie. Because of the numerons other typra of fiber* that may*, and almost errlamty* do, gain areraa lo human lungs where they* become coated with an iron-prntein comjdex, Grom and en-wurkrra (4.11 Miggested the term ferruginoua bodies for these structureand suggested that they* be called asbestos bodies only when it ia known with certainty, or ran he preturned on tV bans of known in* waste reek, why rolantl. The evidenee atmngljr favor* the exposure, that the central fiber of the body it in head cobbing *r fnn-pt that the rnsual exposure of the gen* in fart asbestos. This would appear to he a far 'I r*ihlir ha* not exceeded rush a level in more accurate designation and seientMe atti kninated bhw fiber <p -'post. tude than to insist on railing all of these lion. There ia renam r>'mgino** (oshertos) hodift. In spite of (he jkm* types of mpnri fi*rnng conskirnlions, additional develop* jin the population tl f have raused some investigator* to suggeat it 40 year*. I '1 n epidemic of meaotheliomaa will occur kborhood or paraoemj the general publie in the near future cstoe in the US. it f M This apprehension is hased on the finding w and eo-workers ('M T1"*nnn and associates (3!), ronfirmed ly {fact that none of tkr'^ral vihera, that structures identified a* being l gleaned from a o' *>*br to asbestos bodies (commonly men in leu, f0 into this n" known to have an intrnsrrr exposore to I 'aw fiber*) are found in 25 per rent or mom ^v* dm! the earn lf ah>K general pnbtie by direct rxamma- bodies asbestos bodiea whether or not they are known to be such. The literature concerning ferruginous Indies luw Vromc quite large, and sweeping infer ences from their prune* in the general pop* ulation ham been made (38, 44). Without attention to the iwfeamry quantitative and qual* itativo faetora, it haa been predicted that the experienea of the general puldie with rvspetl to mcaotheiioma wiQ parallel that which hat thus far been dnekwed in certain very specific xcupational or ju" ** *f fng tiwue or of the juiee* preswd from occupational and panoceupationa! twtfmg*. A | rvpceum ean be * '>^,*e. The frequency of orruwente of them number of farts indicate a grant need for cau jrm then 3D per re*1 *7* I" the lungs of the general pnhHe apper* tion before arriving at eueh a ocrioua eon- jfce United 3Tndem depend* upon the volume of lung tieaue ehtrion. To transfer the c*pcrirnee of a apieHW frrpmami-g meetise *ml end the intensity with which the occopathna! or paraormpatinnal population to Mdeh. might be ed1 *** m*. keeaom Utidjian and o*worfcm the geiijhnl publie requinu avidawm that the * -- **- *ri*rt that in their serin abac* 100 per exposure of the publie dnaa, in fart, eorm- DOU 06946 S T 00I1664 474^ ipnrf.to- ikn*ptMktM in which an in- rugineiia laalm is M'rnrv U'forc soy n. ingfnl intcriwctalion of their itniswisnee Thii m rapurinlyatme now that H has been rlmn--trslrd tint there are snme nmi|*tmul pnphtMM>M -the ex|swnt* '< asbestos fiber emends many fold that of the .*! publk ud fa. whkh. m evidence of an uoueual llie general puldk can la> made. - The finding of ferruginous Isalkn in fc,,r. preportinn of the general populatimi lu j to the rommtiou that the augmented n* { asbestos in the manufacture of product* ' mmlf ti -ri wm fntad (13.32,35). What greatly increased the degree to whkh the a the pit-- aha tinn is thk npri? end publk has Ism exposed to this fi|,,t As adialri la foregoing disciwaiooo, coo* This aasuinioku Ins Iwm based upon t(. t i Kaii-- a itfc i raganl to the relationship be- simple atatislk of aebestas consumprioii,Wn' * t*aa aagtUaM tad asbestos fiber per se, no attentka being (add to how the fiber r even ia aa ossapatiurul setting, are rather un used aor tbe degree to whieh its altkuo certain at this than. Hie mica of types of fiber, fabricated form would lend itself to dbssaw-i nation of fiber among the publk (30). A1 I bring clear in these speeial occupational mt* though H is pomible that augmented --a*-' *1 tap a to grr* little asainnee that they ru be tku of ssbeetna fiber led to a greater osays.*. * traafrned ia any n.eamogfal way to the of them fibers from factories into Use air m no--epational refated tr general pohfie pope* rounding tbe factory, thk does not ktk--s. --miked publk environmental v Although a scant number of fermgiaoaa Tabcrthaw (15) has pointed <sit thataskto* { wtM^- OBI OBI WQWVUltCQ OV lOBp lOO is 'need for the most pert in fabrketke tbe pscnl pobfir, there has bent no demon* materiak that are onlikriy to heeaam -ns ^ station that these are in fact the resell of borne. It k not widely appreciated that tV . exposure to asbestos fiber rsther than to oos balk of tbe prodnrts using asbestos aetaaE j or more of the many other materials known bind the fiber firmly in the product, and lb to be capable of producing ferruginous bodies. is subsequently very little opportunity far r At this time, the determination of whether the lease of thk fiber except by slow wear of * fibrous tore of a ferruginous body is in fact products. asbestos is extraordinarily difficult and quite The estimated consumption of asbectas Bf ~ beyond tbe meant of other than the most ia the VS. has increased from 125,000 eW sophisticated laborslories, la spite of this, the tom in 1018 to 720,000 in 1985; mast of tb aoeensary investigation most bo done before meterne occurred after IfMO.* Once tbe S** theoootentiea that an ferregiaom bodes in tbo In tbe form of a product, k put into pin* general public are ia fact asbestos fibers eta it k not rekaard except by gradual ssoak.ufari be accepted. Hi most examples k minimal. During ifiiSk' Quantitathre estimates indicate that the processing, the publk at large k not oxpitol&' number of ferruginous bodies found in the During the use of certain products, --4`* U lungs of the general ptilrfk is a sman fraction instilstinn removal and application, fiber* ** of the number found in the hinge f those released and those in tbe immediate rirlw who bad bom oeeupatiomRy exposed. If one workmen and publk, may he rape--I Tt * accepts the contention that ferruginous bodies reflect asbestos exposure, one must conclude that the general public has had far less ex* pnrere than those persons in omipatinrw go* mt asbestos fiber. That some persons with known occupational exposure to asbestos fiber category of preduet ran be thought ^*' laving fibers that are "loosely fionnd,* k treat finer to aurh products as asbestos ecru-- tile whkh actually incorporate tbe !' t tv and bind there very tightly. The qimnii asbestos filler used foe "Innsiy hound" ptsh1 appear to have but few ferruginoiw bodies inrfading insulation (firire II. has Hwem-- complin tec an interpretation of quantitative measurement of ferntgimsw Indies. It is clear that much mere comprehensive and reliable fmre XlflOn only to ,000 short tons here**' 1920 anil 19fl5* The enmmerrial grale of fiber ind'ret** ,fc fr. data with regard to the dynamics and the kind of prmluet* in whkh it will Is* pmatJtativw and qualitative asporta of fts ' Pmdnrk. K.: Personal eonunmirstiew. DOW 06947 A*Mt>TOO AND Mf.ALTII IN IMO 473 **fi*r tiny mm* inijwrianre t.* u. . a. iMAorrrs cm*yotiuc only S T 0 0 I1665 UhIwii m a tatf. 'li[Atmn hM K ugmentcd ur n: | "f product* ki-l whirl* (hr fr*. j .il to this fibn land upon tl* orwumption, wnL how ihr fiber Virh iU ultimat. itself to dissomjmhlie (30). .\|. rmented raneurnfv a grentff ampu> into the sir sm> not constitute mutil exposure mu that vhotA fabrication oi . become airrcriated that th asbestos actual!? product, amf tfwn pportunity for rslow vnr of tl*r }'hi. 1. Aioount of rhrysotile aahestoa (ahort tons) used in the U. S. duriac 1930 to 1005, irrnrdint to the aradc of fiber. Longest fiber* art grade 3 and *ln>rtr*t arc gruiv 7. "l.ooM'ly bound" pmlitrln include inmUtion and other material* that may reletiae fiber* during ue, inMallation. ur removal. n of asbatn* filar rh.it nioet of the augmentation of consump* rotn 125,000 ahon n of rhrvsntile liar been in grade* 4. fi, and 1905: mart of thr (especially 7) it ahown in figure 1. Grade 3.* Once the fiber. ' rn*> predominantly into asphalt and vinyl >r put into plaer, or tile which usually ha* a life of 20 tn T-idual wear, whirh * yrar* or more liefore it ia changed, aa a al. During factor? *'lt of decoration alteration* rather than 5 i* not exposed, "rr. The hulk of grade* 4 and C goea into i products, such - leatna cement products, especially ahealos dkatioa, fiber* an mmt pipe, in which the replacement time Immediate vicinity. indefinite--system* now in use are more than . Iw exposed. The *' virtr* old. Air eontamin.:tion doe* not occur V thought of a4 hm tha rource. Although there may be some flv bound," in con- mhering of asbestos cement ihbgfrs and arltemor cement * ine. the rate of wear ia very alow. .It ean corporate the fibre *lih he aeen that although there hag been v. The quantity ri * augmented utilisation of asbestos fiber, th* 'ound* prodii'-r- 4frmt fraction of it has gone into strongly r, haa increase! nil product* df*igned to Inat many years. abort lima letawr ^ wear from these products is also far Isas ** the total product by the time the ma- I filer radicate* tV b discarded. I it wit be uwd Idawtoa form* an exwnthl part of friction dersU*. Concern ha* hern expn iwd that tha public ia exposed to large quantities of asbestos filter liberated by the wear of automobile brake linings. Tha ia unwarranted. The amount of asbestos fiber used in friction material m the US. was estimated at 33/XX) tons, lea than 6 per cent nf the total in 1005.* Studies of the ma* terirJ released during ths use of brakes (44) demonstrated that the high best nf friction destroys the abctos converting it to an amorphous material no longer having ths char* aeterarties of sabestos. Of ths total material* removed from brake finings during their ussy leas than 8 per cent appears as actual asbastss. The amount of astasias fiber released by normal friction material wear must bo small indeed. The fibers that might.be released from ad kinds of srsar either become intimately bound with the soil or are captured in either rain water or in water used for cleansing. Ultimately the fiber* are distributed predominantly where water is distributed. A study of rim water has shown that asbestos fiber is almost univmally present although in quite small amounts. How 1 DOW 06948 47(1 (HNHJIS W. WRHillT TAKtJC 1 of filters in tlie general cm irumiMiit ss s r< Anovxrnr CuMawan. T\tr I!ki r>* Varkivk of winr. It is obvious from these data tfer I'rimiuhw is m I'X (Short Tosr is I!*'") comte.-rcial tale provides a (sitenl ersirce r Total UX HimMpiMi iwim riiirt KoofiiR I.....lifiira Paper Itefiactorlea IttiMnr* Stn,n ao.onu 153,000 /2,0IW IV,000 45,ono 41,000 31,000 least etpiivakiit tn that of ads^los for oqipiy. inc rrapiralde-eiaetl fiber* that could pradon ferruginous bodies. It is dilfiruk to conceive a Inner way of having fibers inhaled than tj use of cosmetic talcum powders. In this re. sard, it w of interest that Avril and Champrit (49) found no fernifinous bodies hr tat Toilet piipimiww Other 28,000 107,000 autopsies in Krone*. It is claimed thntdo cosmetic talcum in France has no fibers.1'TU|| Tula! IL*. rnfRiiim|(Rin of iiImIir in IW *w extent tn which other mineral or v ;2l,iai ilmrt low. fiber* known to be present in flaw mtiit of tire fcneral jHiblie may eontribmr mwh uf ihit mmrw from wear of products and how mueh from leaching of foil i> of course not determined. Tile concept that asbestos is indestructible a fallacious, ami t e belief that it accumulates on the surface of streets and other places seems ill-founded. The powibility that smirrcs of fiber other than ronimcrri.il asbestos may lend to fcrniginous bodus must he conflicted. Tale is a form of mssiKKium silicate that exists in sev eral forms, has large industrial use, and com monly is contaminated by fibrous substance* ruch as trnnolite and even cltrysmiie. It shot!Id be noted that talc production has been hnwn to cause pulmonary fibrosis and possiM.v in fluence tlic development of bronchogenic can cer (47). As shoim in table I, the consumption <f commercial tale in the VS. exemls that for asbestos. Attention to some of the prodoets made suumta tint the np|inrtunitirs for airtome tale dimemiiMtinn may havp been migmenteil to an even frenter digrre than Ins nsbmtas. Crtllcy and amoriatr* *4*). in an to the production of ferniginuus hodlea^iajm yet unknown. Data have been reported recently bFi ami Himmond (50) showing that the fi of omitrencc of ferruginous bodies- j tiaIVy the tame in lungs obtained hy attfoper 1934 as in 1907, a finding difficult to recenr with the contmtioii tliat the augmented use ai i a*lntu* during the |st .15 years ha* grmth enhanced (he exposure uf the general pnMr to asljrstos filer. It also raises the question ef wliethct the fihers in these ferruginotts bedm are in fart asbestos. A simitar study in Grret llritain failed to demonstrate any feme* nous Indies in lune ramplet obtained at an rropsy in 15M or in lung sample* from-fr male* autop*ied in 1940 (51). Alt may have been fewer than now, there must have Inert intent sourer* for the d nation uf !w*tIt tale and ashestn* in tlmtj Itrifiin Infur* 1950 and 1040. I The previous findings provide little or a t evidence to suggest that an epidemic j .imminent of 22 cosmetic ulrtim powders mesothefioma among the |nihHe at large purchased in the found tint an average In expected. In a more positive way, the dtf-j of 30 |R*r rent of the jurticles were filters, from South Africa itulirate tint during (he 'nunc filters are fully capable of pnslwring five ur *ix year* the numhrr of new ewn* . ferruginous bodies in the experimental animal. imvothcliuma have hern rather constant ** It is of interest to not>- that the amount of approximately 30 per year, and in commercial tile that ultimately finds its ray Itritain (55)* only a moderate inerean* ! into toilet preparations is far in exert* of the Inert elmwn. amount of admit m used in the manufacture Although tin sttulv of ferruginous ls*h"` of insulation material*. Insecticide preparations i f interest, tin mronity for the n*"* j consume a iaiRer tonnage titan all of the tin- cure to In identified and for quant noth* !'*. hound kinds of asbestos fiber put tiwether. in In obtained in order that mure mnw'**' J Kuidter, which utilises a large amount nf com- conclusion* hr reached atom their 1 mercisl tale, may contribute to the di-chante *.tiril. J.: Pitor.iI nHi.miiniemtimt. S T00I1666 i DOW 06949 I -JR'-- AMtRTos Ara-nuim ix v 477 * ' s h* I mietu that thia an area of (tody with epidemiologie point of view it i proper to * data tk l ilnnmahinc return*. A direct approach to tho consider these findings as evitlence of asbestos t source J fur np|4 iM |ina4% ' "inw | Ifl <htm u more raaily identifiable naked fibers contained m the June would appear to be a more fruit* ml avenue of search. Still better would he n .Inert approach to the types aad amounts of Mar present in the ambient air of the rarioga Long-term implications of pleuraI pbquee are a matter of interest. In general, unless tho thickening of tho pleura i extensive, the effeeta of this patchy thickening on varioos as CO --d o o In thw * environmental locatiamr that are of interest pects of pulmonary function are minimal or i C1UB|> nh rrvpcet to occopatiunal, psraoecupatiocal, absent * There is no evidence that the pcemneo o\ cr* iN m r and general pobTie exposure. Although this of |ileunt plaqucv ronnmee anything with re *d that it. J filvr*.* Ttj f vfjrtjti1 ( lir cuvm* * m<nlw would pane the dimdvantage of not giving information with regard to Jong-term past exinsure, there equally no guarantee that ferruginous bodies truly represent the complete history of past exposure. The direct approaoh spect to the ultimate: dexrtopment of mmoths lioma. In fact, two of the geographic arts* in which the largeet eoocentntions of pleofil plaques have hrm reported, Finland (52) and eastern Quebec rrovmro,' do not have a - I lindm* - to the rtudy of fiber populations in llte ambient demonstrated excessive frequency of air would hare the advantage of teflon ee homo. To tan the presence of {dcnral by Schk* *w freqiwsr what the eonditiotM are for the public at pres- as a marker of previous asbestos rat. of limited vahie, in view cf the fact that other i* .topry to record rnted ne * h gmd neral |mN> question inmta Mr ly in C.fw jiy fernr .iiicd at * c* from fctliotigh tfm there surrh the disscnr ti in rtnrrti pfoqwti Attention has been directed toward another phenomenon said to be the remit of past exposure to asbestos fiber. Since the first recognition tint prolonged inhalation of asbestos fibers might in some persons lead to diffuse pulmonary fibrosis, clinicians have lcn aware that arena of thickening of the pleura oeeur in some such persons. At times, thia thickening is localised leading to the ap pearance of plaques, some of which may be ealcified. Tho pleura effects range ail the way from minimal findings to extensive and bisarrt, irregularly shaped, eeleifie manses. Pleural plaques with or without ealeifiration art a matter of considerable interest at the present time. Unexpectedly, throe manifestation are causes lead to this condition and etpeemly tfr view of the fact that the absence of plaqpea in no way eenuotes the absence of abeertoe rrposttre. The relationship between asbestos and health of humans, aa revicwable in 1969, indiestn that' serious expostires to asbestos fiber ean oecnr in certain occupational and immediately ad jacent environments. Fortunately, tho (to^ cent ration of asbestos fibers in tbera setdnpK,. ran be controlled. Tho environment of the he-'- "' sulation workers la more difficult to Hld than the more fixed and permanent environ* ment of the factory aad associated neighbor Tittle or *rpilfinir *{ : tinr** * ' ay rlie di* { -in* the !*' iew n** * J rou-iant '* I in W- often absent in persons who have well-developed diffuse pulmonary fibrosi* resulting from pro longed exposure to asbestos fiber, and they may he very extensive in persona with little or no diffuse fibrosa. In fact, rather extentire |4niral )i!aquce have been reported as being common in large population* not directly exixwd occupationally to aslwstox, but living in *r near the region where asbestos fiber is being hood. An approximation of the tanetnrratlou of rropirablc--iii'd asbestos fiber that ean bo tolerated without the risk of pulmonary Atari** has hern achieved. There is reason to Ufins* that this concentration will al*.i minimise the risk of pulmonary maSgnaney including nuniheTtonw. TVeatis* of the long tiros (apao am sueiated with the development of malignancy, longer period* of observation are desirable for a produced or used (52). There are, of course, final (lection on this point. There is rossoo to nous Issh" iIh* cetu*-, titatire d' mraoine*' b*ir mr* | other causes for pleural idaqura and ealcifi- ration, and, in some instances, it is unwise to crilw throe (iodine* to the inhalation of abctos fibjr. In a geographic arm where achcMtos fiber is known to be present in eon- dderable eoncentntinn in the ambient air, * ......................... ** Iwlieve that the occupational u*e of asbeMoa fiber ran achieve the asms degree of safety aa the use of rxptodvra, radiation, and berylRuea, although extinrive alterations may be tequiied in the control of production and Rubutaetariog; t IWcktske. Xf.: rcrsonal < P Prrwm| rrwntmmiewi 0S690 noa 8991/00IS UcpMtMl of Miaco,- RepobUe-ef Afrim.lM9.lo he publiebod.(14) Kntcriiae,- P. K. aad Kendrick. L- Ad itrinotni lint muirtr il mi mortality, Afrit. Environ. (Pitman) 1997,/#, HI. (ID Muw, T. F, mi EUUUr. A. B.: iWtud dmtin of mf' 1 1 *1 ( * J 1 tJ # * * I* *->. -rl k-\ V. J it. REFERENCES' (1) Sped. 8, J. P.: Icdmlacr, Eariroa. of hiham, RepubHo Afrioa. 1M0. to bo pubiUhed. (17) Baker, I. L. aad Cooper, W. C.: oavkoMBoah'of bmriatiw ' ladaatr. Ryv.Aaoa.7. IMri (tD Harriao, P, O.: Afboatoo haaaida .It dockyard* Aw. (heap, Rtu (If) CtoBcy. L. J. Xccaaa, R. O. ai JLi Ripnaara to awUio ia.tha tom of ariaotoo textile Mmtrr. Her BiHtn Sutiomqr OSaa, ladaatr. Hr*. Aaaa. J. 1997. ff. M, -w"` ' (19) Crmller. L. 4. Xfeaaa, R. O. XapdrM (4) bjm R. R. aad Puma. W. C. Khmer, R. E, aad Lynch. I. R.: Char* Amer. J. PaMic Health, 1931, ft. 308. actoriaation aad aohdality of meUla aa- (I) Kaos. F, Hofaoa, 8, DoO. 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Smith. W. K. and Deritoer. 8 W.t Tcoto for effect of aPbaatoa oa heaoo>(a) pmne carrineamorie ha thn ito4ntoey> tract Ana. N. Y. Aeod. Sri. IMS. ttt. 9< (39) Hariactoa. I. 8, Roe. P. I. G. aad ~ Oou 695l hr latni of Soulh It. Ai Imh . Health. K: 0 lofthoi the Bio* tha later* of heath The aw* tern, Aaer, . ia ami mu. m. f ' **orh. J. ( aufee* x . Amer. IS. a|id, R. E. II.: Cher* nrtill 0k ter. ladaar. immead, R. among ia* Statce. Aaa. Rreolta at riuutrli-- m ee. RipobHe 4iehed. D.: Aa epi* err in iAw hint. Hcelth. unaa.P.aa4 1 ntodjr flf Italy, Med { a end ac*> her. K. Ke** The denhe -wlmonaiy ..i*tn, .Asieoh.- erfiner. f. W.: mm hraaa (> . nqiiilMT Mt. m, * F4"" AO! AK1 ItmALTIt IN I1 at Mba of R.1 Premdaoue Udi**ta.l.----- --- . I. Afr.- Med.' I Arrh. Karima-. IfealUHCHknank taUMbfr- S7.~ 39) ' tathefocind aapreta of 141) Genoa P. da Tmrflle, K, Crrikrr. I* /. i the 1'kinR ol South Africa, Daria. J. M. (I.: Ihiltnnnary In T of the racuuMcociiaae Caa- borfim. Arrh. Path. (Chiraea). IMA mm. IMA Juhcaai riierg. Little, Bmera OR. I On. Rmtaa. IMS. (M) CraHer. 1*. J- Keeaaa. R. G, T.vorit. J. IU (SI I. C.: Health haearda at Mbcotar. aa iU htakcml eflecte, aad Latahorf, W. S.: Source and IMI Cri f^PVWRW AIRT Tium. fca. Oeeop. Med. 19M. 19,. Hyg.kam.im IMAM, HI. (31) SaaGmana O. X.: Achrataeie ia South (43) Groan. P. Crafler. L. J. aad de TtorflA X*t Africa, certain ocoamphical and iairaa> "Ariwetoa bndWU Thdr mental lamHiwtiena, Aaa. X. Y. Acad. Aarr. ladtr. Hyp. Aeea. J. II sri.imsr.tu. (44) Bahbori. I. J. Bate. R. A. Rate, Jf. S. (9) Chobot, i.i Primarr tamom at tha Chant,/, end Hammand. K. C.: aad ami'na at the leap Aebmtaa aad aenpleria. Amer. /r-J to ateetot Fbomea Coear, IMA. U, Sf. lSS.4t.4B. (S) CQaea.-J. C.: Aebertoo health haartfc faecal (43) Tabeieharr. I. K.: Aebeatoa aa ah elner.itjam ia U. X. Fwirndtapof tal hasaid, J. Oceup. Med. IMA it. Jatcvaetieaal Cbnfrreom am Pncocm roainrie. Department at Mtaea. Uaioa at (41) Lynch, j, R.: Rnke luonc roq>poaiflof|Wd^' Seath Africa, im to bo pnhliebed. oeta, J. Air PeQut. Coaatr. Aam. IMS, tl, (34) Ghwbaea, i. aad Hunrita, M.: PtoMema in the diecaaeia at primarr didace (A) KlriaMd. M. Mcorita. J. Koojrmao. 0. aad aad id rriatka to SaU^M. H.: Mortality aamos.talomimmr; Interactioaai Coafe and mBota in Nr* Yorit MaMt^BNMT' Deoartaeat of Miaea. Earima. Rcnlth (Chieaim). 1M7./4,m Uaioa at Soath Africa, IMS. to be pub- (43) Crailey. L. i. Kar. M. M. Gmth. D. li. Laiahart. W. 3. and Lin. R. M.: ill) MeOeaaM. A. D. Harper. A, El Attar, 0. and mineral content of eoamatk A. and McDonald, J. C.: Epirinriokcr peoduria, Amer. loduetr. H.m. Area. /. of piauy malignant mceothelial tumnea 1908. if, 3S0. ia Qnada, hatrdhp at Jaternatioml (4f) Arril. J. aad Cbampriz. J.: Rudb ef Onafirraee ea Paeaiaoeoaieeia, Department adwetoa wpaan in France. PreaolHP el MImi Repuhlie el South Alriea, IMS, ol latematiosal Confermc* an Paeae* to be pabliahed. eoninoia. Department of Miaea. RephbHoof fW Wehetar, 1.: Aabeetna npneuie ia South South Aftia, ISM. to bo puliliahed. Alriea, Ptarccifimi at Tateraatieaal Coe* (10) Sriikolf, 1. J. and Hammoo*l. K. C.: fereneo aa Pacamcrcnioaic. Department at bodiea in the New Yorit Ct>* i Mtora. Union ol South Africa, ISM, to ba two penom 01 qm* i iuci* u* natiocud CoafemKO <S) narrow. II, Goaatoa. A, Urerpeae, L. Department of Mince. RmUb at Maultea, S. E, and Schalet, N.: < Africa. 1M0, to he publicheo. Mmothclioma Mandated with eaheetaala. (ID Pooiey. P. D. Oldham. P. D. JAMA. VCT, SOI. UtT. Um. aad Wanner. J. C.: Re itrteetieo at '* Theaaaa. i. O.: Ariwetm aad the utbaa aebeatoa ta tiaauca. Pmrvnlinaa of Tatar* H. Y. Aaad. Sri, IMS, l. nattaead Cbnfaimee on Pat ia.amntariet Deparimmi of Mtaea. RepabBe of '*> Thoimm. J. . Kaariiula. P. R. aad Mae- Africa. ISOS, to ho puNtried. Deaald, R. K.: Aebeatee aa a modem (M) Raunta. V.: Orcumnee of unusual pleural haaafd, S. Afr. Med. I. 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