Document r0qr89B53LapE7oqa277mLGe

<XU VB XT i Ji Australian Blue Asbestos Limited Tn/CMnne adumvs "Ui-UtlAOCK* * Oi/' V/ITTENOOM WITTCNOO^ GOr'id: PKTVATE lteatv^ir^T Director, Australia Slue Asb^stoa Idoitefl, Det-r Sir, P.626, 24th June, 1960--^ * ASB^STOSIS* Ve ennioso for your information tvo copies or un extract tt*kcn*froa the British Medicd Journal* It is quits cn interesting erticlo and reveals severs! fa^ts not haavn to usbefore. Thore in quite n lengthy clinical <5occript5.or.of tho caso t3.se in this issue or tne Journal, Tours faithfully,. Kftnflgpr.. I oaVcs. * l-yirtAOr lnl.cn from tho British Koriicnl Journal of 3OU1 I'pril, 196') heodod "Cor.iplicntlono_of Asboutosio"* ,Vr-U^TOSIS Pi^TF.JKP. Professor JJfcMichnolt Er.nugh-Jones, would you oum it up? Dr, Burh-.Tonnj: The case is of p:re-at interest* as it demonstrator. so ct.-,ny of the problems associated with asbestooic which t;e should review, Asher (on itself io chiefly a doublo silicate of magnesium and iron. It occurs in a nnriber of minernlo&icnl forms, one ol' the cost valurble being chrysolite, Asbeatouis is a pnounoooniocio arising from the Inhalation of asbestos dust during the manufacture of asbestos goods, such ns asbestos sheeting, fireproof clothing, brj.kc*-linings, lagging for boilers and pipes, otc. One way of thinking of the pneumoconioses is in relation to the chemical toxicity of tho different dusts. At one extreme are those, such ns lrn> which are entirely non-toxic end simply produce a characteristic radiological appearance of tho lungs with no change in bodily function. Titan ecac others, wch as cccl, which do this but also have a pathogenic action by altering the reaction of the lungs to tubercle, Next thore are dusts, such as-silica, which produce n local reaction in the lungs and nul&onyry fibrosis. Finally there are otfiurt, * such as beryllium, of such toxicity that they can be regarded- as goners! tissue, poisons, which produce widespread effects in the body as veil ns local fibrosis in the lungs, Asbestos in vciy^tcxic and produces not only prlr/inrry fibrosis - but reactions in the* pleura and even in other organs, Pi',hoard hr.s excellently demonstrated tho pathology of asbeatosis in our patient, but Ly way of euMZJary here is a picture (Fig* 12) of a whole Ian*; section of another patient vho .died from asbestocis* There.is an interstitial fibrocis, as in the present case, gross pleural thickening and some patchy bronchiectasis. Besides these three features, which ere coavon in asbestosis, there way bo associated tuberculosis, as there was in this second case, or, ever, sore important, associated lung cancer* as in our patient*. Sometimes the interstitial fibrosis giro# rice to tho formation of bullae, or occasionally oven to a widespread "honcycocb lunr" - i.c<., that which ocebrs with other rare forms of pulmonary interstitial fibrosis, such as the xanthomatous. fl/\DIOT.GOICAL AFFFAHAHCBS. These ere typically those of a fin luco-lihe reticulcr pattern, ptriie*tlei*3.7 affecting tho lover lung fields and causing a "shaggy" border to the begirt, as in our patient., Besides this, cystic change;, cay bo seen and very often the pleural thickening* Although the X-ray picture is typical and '.Irast pathcrno^nic in a few adveneed cases, thv-re ere meny patients who have undoubted esbestosis (as judged by a history of expc3ure and tho clinicrl fhfeturax of clubbing, rclcs in tho lungs, end typical changes in lung iUr.ct'.or.), \*tx, do not have specific changes in their chest radiograph. That is extrwreZy Sssportnni in relation to tho diagnosis, as wo, shall rco later, because in ^crcrsl the diegnosis of pneumoconiosis depends on an appropriate industrial history and a cKoracierist-i's X-r?y appc^ranco* There if. a. ch?r*.ct.erirtic X-r^y appear?nce in esbentosic, but unfortunately from the sadlco-legcl standpoint not ail pat5 vith osb?stosis have the characteristic r: diogr^ph, Fim liy, ~tv'C radiological appc<'-f.nccs of asbestosis cannot bo ehssiJied in tho same c>icori*i cc those accepted inton.atioally for tho other pRcuiOconiooes. -2- p-TT?:Tr.-'T. rrVTJPES <nm rnimr.s. 7 ?Cf '` Gross clubbing of tho and nnrr/'-.btent xrdcs in the cheat err* the: characteristic clinical signs of the condition* Kxertiorud dyspnoea is the nuir symptom as in other pneumoconioses, Patients suffering fren ar.best.00i3 u'.vj die joithor fi'om the._coapllcatio.n of tuberculosis (more common in past years}, or more ^i?tic!il :r).y from that ,of..carcinona of tho lung. Those not kilic-d by ' chest' infection or cenccr may finally get cor pulianalo. The disease usually makes its appor.reu<*0 rather suddenly, over the dourno of a few vpnths, often long after the initial exposure to tho asbestos inhalation* It has been suggested that the asbestos lie-;; dormant as <\n acbc.vl.00 body, vfcich has to "ripen" over nsny years before it. can bred; devn end liberate its *.,>:*0 contents. In this respect asbestos is ega^n like beryllium, which nay al:;o lio domant in the body and then suddenly produce its effects concurrently with some other infection* Carcinoma of the lung is a serious and veil recognised complication in esbostosls* Its_freouency In esbostosin is difficult to dettv-vu.no, for it is ixr. ^ a common condition in the general population* Moreover,, exposure* to asbestos ' way"bare occurred ueny -years before 'the .cancer develops. . .tfevv:i'ih*ltn&, tbs f\ by roll makes it fairly clear that a patient with asbesdfcsic Haifa `risk . , f'.lt.ly about 10 tiiaes * that of the general-population of getting: crrcinc;:a of the lung* .C""/* Another hazard is mesothelioma of tho pleura*' ibis ralhcrrer? tumour n:; drr.v ctteuvtoa to the fact.that a patient has'vorfccd in asbestos dust. Finally, 5n woseu_vho work with asbestos there is a high incidence, of cancer of the' ovary."'* w rO?STIO:-?AT. FFFEGT3* There is a diminution of the inspiratory capacity which fit;; in with the * shronkc-r. lung" demonstrated by Dr.Heavd in this case. In contrast with other pneucscowircss there is often little disturbance to air flow, so that all tht ffovaaent of tho'slungs there i3 is used to good advent/**, and tho y.*^cr.rau breathing capacity (H.B.C,) is often surprisingly veil maintained, Thus if a patient suffering fvoa asbestocis is assessed by tha or forced expiratory volume ) test, ho i3 unfairly asr.enr.od for compensation compared with a sufficin': from silicosis or co.vl-vorkers* p scumnnoniorir.* The essential cause of the brcuthlessnccs in asbostosiu is the difficulty of trana'orc-neo of n,r.*?*?u r~ aerosc the altered alveolar membr.iu<*e, mova so than the reduced wiwa breathing copacjt/, which is the dauss in, say, coal pneumoconiosis, fbrfeon di being soluble, dif:*uses 20 times as rapidly as os^g&u and is unaffected. 0;p.~n-n transfer is usually adequate at rest, so <hat tho patients are rarely cyar.osci. cf whoa they start to exercise there is a rapid fall in oxygon saturation and gi-ors Ityoenonava. Tho diagnosis is cade on a history of exposure, the nreannee of c3uhbic*: and rales, rad usually by neons of a radiograph* Ther* 5c, hovnvor, evidence chat the r?:Uevr-xh may not show changes as crc-.-.y cs do the 2 ur.g~ Tuition tests* Altho:i;:h tha latter are not specific to r.sV*stasis, they are e::5.y sees in ct'** v unsom.ncn ui'euses which cause Avcol?r-cvj11rry block *-ud iatv.titisl fik.^sis pa til I block, h*3 gross clubbing nnd rules, and a history of crponuro to uabcsuos dunt, it se-;nn reasonable that ho has asbestos!:* whether the radiogmph Jo opoo:U*ic or r. ASBKST03 DUST The asbestos bodies simply privo exposure to asbestos dust and of themselves .do not moan asbontosis. Anyone nay cou;h up asbestos bodies who has inhaled dusti without necessarily having the changes of asbestosis in the lungs* Vice verso, r. patient nay havo definite nnd cross asboitosi3 without asbestos bodies necessarily being found in the sputum during life. Since, medico-lcgally, tho .diagnosis depends on a history of dust evposuro together with the appropriate X-ray and other changes, the finding of asbestos bodios is of importance in proving exposure. It seems probable that asbestos fibres* once inhaled, aro coated with collect Ovor the course of years the collagen cover "ripens" by forming transverse crocks, and then the asbestos body can break down, liberating tho toxin and causing tho reactive fibrosis in the lungs. The nrture of the toxin is uncertain. It is, however, presumably the sane substance which is carcinogenic. Asbestosis w*s first described in thi3 country by M.llnrrny in 1907. Af&er - that,~in 19~3~37~Efer^Wather' and~Price reported tho dangers of .csbostoc^dust in*tho for dust suppression*___ Thereafter there" wan a lory whero cur patient worked the-wtaast----- --~ svent asbestosis occurring. * It, is a disancoaring DISMISS!03. Professor HcMichtel. There are many other facets to this patient, butbefore we| go on to tho:? are there any other points or queries which could be raised on the pathogenesis `of asbostoais? 7* - Dr.H.S,Minims. Xthink there is one point in support of tho ucchadccal theory that is worth raising. If experimantofI7 you gio asbestos ground up into a fial dust, fibrosis does not occur, aud it f-oius that asbestos fibres **'atuaen 70 nr.d ^ microns in length are necessary to produce the typical peribronchiolar fibrbsir* mSTHTSOTIOT OP PJ.FROSTS, Professor E.G.l.Pvwntsrs. tJhat is the explanation of tho distribution of fibrosis/ Dues it correspond to tho distribution of asbestos in the inns, or is there coo0 other explanation? Pr.Hc&rjL As a matter of fact, it doeaa't scou to correspond. Although sonc of the*-best asbestos bodies :in this cans wore in fibrosed area.*, there vers plenty surrounded by perfectly normal ling in other parts. ?)r.llngelsc;*- '.It, fr: Sheffield, was hers two days ngo and he was saying that they havo recently examined chemically a number of lungs f,oa cases of asbestosis. In there A* i t via r. lot ir fibronis .v.ud practle.-jlly no asbestos* Hovcvcr, ho did point out t'. there vao '. y *".jlblo error bacaur.s the asbestos content vas estimated ns the percentage c-the dried weight end the dried weight of fibrosed lung is not altogether evvjoreblo to the dried wsught of the normal lung* It in quite a problem, r-:-A, ro for no I know, th*> periphery, distribution of the fibrosis has N. been cxclr-iivi'l. It is not re&tricted to esbostosis, being seen in other forms \jf honcyror.b lung.