Document OJD3GpbgMG7nwobn0ygzvzgEv

FILE NAME State of the Art Literature SAL DATE 1938 DOC SAL026 DOCUMENT DESCRIPTION Book Excerpt - Asbestos ane : we me 9 aw tan odes 4 0 qo Women 4 eee Pplctr eet RS a er Lage sae 76 Association of American Railroade submitto c In case of total and will be the death benefit permanent disability the maximum compensation compensation plus a pension of per cent or in certain cases 12 per cent thereafter annually for life payable monthly On petition the Conunission may order an autopsy by competent patholos gist where death may have been due to silica or asbestos dust Pathologist to make rompiete report including laboratory findings but offer no conclusions Employes making claims for compensation must subanit to nation if required by employer Employe is entitled physical examu- desires If employe refuses to submitto tu copy of report if he ^"ntilsuch exanunution is made examination compensation compensation eri Employes with siliensis or asbestosis but not disabled prior to Octolwer F. 1936 may file with industrial commission within 60 days after effective date of this act a request to waive full compensation silicosis compensation for disability or death from . or asbestosis or any direct result thereof supported by satisfactory medical evidence If the industrial commission approves such waiver the compensation payulile ^...terfurther exposure and resulting death or diss ability shall be 50 per cent of what it otherwise would have been Notice of disablement must be given the employer na soon Cluinis for compensation must be muude within as practicable six months after disablement and applications to industrial commission for compensation within one year Any length of time however short is sufficient exposure to support a claim employe was engaged in an neenpation neenpation or process in which the huzurd of the disease except in cases of siliensia ur asbestosis where the must be 60 days or mite exposure The employer liuble shall be that one in whose employment the last exposed to the bazards of the employe was disense elaimed except for silicusis or usbestosis No employer shall be liable for compensation any case in whiefs the disablement on verurred prior in October 19636 compensation ve damages under which claim is predicated klas Art an small have Chronic Arthritis the When referring to chronic arthritia wee sismally mean either of the two great types of chamie mousspecilir arthritis In the language of the kuity we sprak of this as chrome rlaunantista We filist not delinite clinical forget however that there are groups of rlrode arthritides of knowa etrodigy tintarly hans and tubercular These litter ate sporitic disenses vasily rrrrgnized as a mile ami if tivated in early stages of the disease processes are amenable to treat- ment Numbers are entred permanently and the end results in reference in disability are not clandest by the sinister threats of the crippling agonizingly painful and deforming onslaughts of the chronic specifie arthritides rheumatoid arthritis arthritis and hypertrophic hypertrophic arthritis as Rheumatoid arthritis must be entirely separated from the aente discase of rheumatic fever known also chronic infectious arthritis atrophic arthritis arthritis deformans rheumatoid arthritis is the most prevalent of these two disabling disuses chronic infectious In Cornell Clinic series of 012 cuses thirds were of the or rheumatoid arthritia type It is minst often seen in oe ete Tmt bene. og wea Ca- fr^nalesat *** tushika tushika edaran juf . dzorpio Eliulogy keaku keaku astag Ik UL ps AB Lawes pe tans beoe Cape cv ectes se se with adv is the actual actual se car disease Ukanal o^,,sore throat , disatasu will usuall rheumatism Cecil's experiman known to all amil positive jet~ ta libuts by Morketa eksaanwel c^ptervise c^ptervise we are likely keska keska Severnd kons isa Har junta utak to Others have isolati jer ovat Base aumasinkets aumasinkets aumasinkets then then Home Whad farver ~tilles were asojate va sinalar tval's Hesspat Hesspat an No } Vover fey Wonkets abu sate Solar land starpta starpta winke winke nach with me ~ ISTA fia edier ala. : t ... lair o : gi Grashedly than jonar LS La ee a Wetter ge ea ety ee my time over two pum and the tassia^ s tassia^ s oktat partial oc exampine the distuse a Lates a: . the long taies also also grudual in need ri discuse are swelling ankylosis and defort the disease may sku + fingers present the t tae or Sc a Co TRO OTRS et . Ems os \ te 76 3 end nem, _s dendre, sens, aunty tree _ a 4 .. - . any ee wer a ~~. 7 8 OCCUPATION AND dy , Encyclopaedia of Hygiene Pathology 4 cd = a Yrowe ee 501938 501938 ee e HEALTH -- OP and Social Welfare Few, ee SUPPLEMENT OR he, Several years have elapsed since the International Labour Office published its volatza widespread~fl Encyclopaedia of Industrial Hygiene see page 4 of this cover a work which has won widespread~fl widespread~fl recognition as a standard book of reference on the health hazards of industrial and business life In the meantime new discoveries have been made new processes adopted and new safeguards and remedies applied ve , It has therefore become necessary to bring the Encyclopaedia into line with advancin knowledge and practice To meet this need the International Labour Oflice has decided to publish a Supplement containing such additions and revisions as are required to keep the original work abreast of present progress ae a For list of some of the subjects to be dealt with in the Supplement and particulars \ authors see page 3 of this cover The Supplement takes the form not of a new volume but of a series of brochures issu- te o- by instalments on a loose plan and adapted for filing and preservation in a solid binding HM cover t 7 Each article devoted to a given occupation process substance or health risk will be produced as a separate brochure to facilitate the binding of the series in alphabetical order ami the replacement of any brochure should a new edition become necessary at some later date The price of each brochure will vary according to the number of pages it contains The price of the special loose binding cover is - 50 cents The subscription rate for 500 pages including binding cover is 5.00 - ee oe e ore we ewe ae Tye4 me. yee~ em ak te or Orders may be addressed to the International Labour OfficeOffice Geneva Switzerland or of following to any of the following AUSTRALIA ^ reland : or Messrs 11. 11. A. Goddard Limited Limited 255A , George Street Sydney Australian League of Nations Union N.S.W. Sons TO MessrsMessrs Eason Eason and Sons Limited 40 40 and it it Lower O'Connell Street Dublin Branch Savings Bank Building 14-20 Castlereagh Castlereagh Street Sydney League Society of Nations Wellington Wellington Wellington StreSetret t Ottawa Ottawa Canada 124 CHINA Mr. Fong Cheng 754 Bubbling Well Road Shanghai JAPAN Branch Office International Kojimachiku Kojimachiku Kojimachiku Building Tokyo , Labour Hibiya , Offlies Park Maruzen Company Limited Maruzen Ka bushiki Kaisha G Nihonbashi Toro- Sanchome Tokyo or Commercial Press Limited 211 Road Shanghai Great KhiTAIN Branch Office International International Labour Honan Office N New ew ZealANDI ZealANDI ZealANDI The Labour Bouk Room 126 Vivian Street Wellington 12 Victoria Street London S.W.1 INDIA Indian International Labour Offico Indian Branch United United States States Branch Office International Labour Office New Delhi * 734 Jackson Place W'amington D.C. oe78 oe As gts fe ieeeee Y withes ose: aewn ay ' a ay le we be and waayee nn be iPS sortven,sdi(es oe a tylvey & Sahil pewyntwaPeare.5 6 fee, othe = ce teeta oie + ASBESTOS French Amiante - German Asbest - Italian Amianto - Spanish Amianto Aen Asbestos although known to the ancients as a scientific curiosity since they were able to make a inflammable cloth from a substance believed to be of vegetable origin had no commercial importance until the last quarter of the nineteenth century Then the unique resisting and insulating properties of the mineral began to be exploited and thereafter the expansion of the industry has been remarkable The multifarious uses which are found for asbestos at the present day would have amazed the pioneers of the industry _ The fibrous minerals commercially ' known as asbestos are silicates the silica . being combined with metallic bases mainly magnesium or iron and to a less extent calcium sodium or aluminium The term is a collective name applied to a variety of micade mineral 2) is differ from eather eather in chemical chemical cuisition and physical properties but senible one another in their finely fibrous nature and the flexibility of the fibres For practical purposes all that goes under the name asbestos in commerce is either fibrous serpentine or a fibrous mineral of the hornblende group of which the most important are crocidolite amosite and tremolite Serpentine asbestos or chrysotile is essentially a hydrated silicate of magnesium containing little iron and almost no calcium The hornblende varie- ties contain less magnesium and usually more calcium aluminium and cro- cidolite and amosite being mainly silicates of iron The field of utility of asbestos products has rapidly expanded and day is very large new uses for asbestos are being constantly found The mineral the yarn or the fabric composes or is incorporated in a vast number of articles ranging from matches to filter pads from paints to roofing tiles from high pressure jointing to electrodes and from linings to insulating electric noise and fireresisting materials in great variety As mentioned above varieties and grades of asbestos differ widely in their chemical and physical qualities and these considerations carry great weight in the choice of an appropriate grade of raw material for the purpose in view Asbestos fibre varying in quality is of world distribution but over thirds of the world production of commercial fibre is derived from Canada Rhodesia South Africa U.S.S.R. and About fifths of Cyprus the world's produc tion of asbestos is unsuitable for spinning and it is the discovery of industrial uses for these very short libres and the dust- like waste which has been responsible for the phenomenal expansion of the industry as a whole EXTRACTION Hitherto asbestos has been got almost entirely by open quarrying but under- ground mining will have to be resorted to in increasing extent in the future in many properties | After the mother rock containing the veins of asbestos fibre has been drilled and blasted the loose long fibre together with adherent small pieces of rock is gathered up and sent to the cobbing shed where after drying it is dressed cobbed by hand freed from adherent rock graded screened and then bagged ready for the " " market This crude fibre still contains a proportion of rock dust and short libre useless to the spinner which is removed in the preparatory processes in the factory The broken material in the quarry after the removal of the crude fibre where this is done consists of rock containing the shorter fibre and still finer useful material and barren rock The former is sent to the mill for mechanical treatment and the latter is dumped All grades of fibre other than those sold 46 " in the crude form are produced mecha- nically in the mill There the object is to extract as much fibre out of the ruck as possible while avoiding breaking up the fibre and thus reducing its value by unnecessary operations This is done by a series of crushing l I.L.O Occupation and Health January 1938 Comp Comp aoa 4s, o Comp 4:74 ve 4:74 } yt tetmene aneweeNaa '(. ot Deg Us And Botherte Botherte Service < Service } ie : (fo ~ ". 1971 19 19 * ven Er ) Damant Damant u wePeer 1 417in 11417in 1417in Sorb Health fabhi welare co und Educ Heath CIME QR peat fl 35 Dy KE Spee ASD^ TOS ASD^ TOS operations at the same time opening or fulling out the fibre and groups 1-3 crude and spinning grades screening out the are used useless sand The fibre is collected by Any of these alone or blended with means of air suction at each stage graded cleaned and bagged each other or blended with cotton fibre may be spun into The asbestos so produced is classified varn Asbestos suitable for this under " an agreed defined system into purpose has to be crushed if in the crude crude asbestos and " milled asbestng all * " " state and in Crude asbestos consists of the selected cross material in its native cases opened or fiberised " before it is ready for carding Separating to or fibrous form Milled asbestos consists remove iron and sieving follow crushing of all grades produced by mechanical but precede opening treatment of asbestos The subsequent carding doubling spin- ore +, These two classes are further subdivided ning and weaving processes proceed into nine standard groups Crude asbestos broadly as in the case of other textiles but with is graded into two groups 1 and 2 and milled asbestos into seven essential modifications and res- trictions caused by the different physical the groups 3 to 9 characters of the asbestos fibre determining feature being length of fibre In the Asbestos yarn is woven into cloth for classification case of milled fibre further is made by means of the insulation mattress coverings filtering material fire curtains resisting standard testing machine This machine of standard dimensions comprises four clothing etc. Also woven material is manufactured for beiting for brake boxes superimposed one on the other the hottoms of the first three boxes from above conveyors and insulating tape Asbestos millboard and linings downwards being wire screens of standard asbestos paper and * dimensions and cement sheets tiles pipes etc. progressively finer mesh the lowest box retains the fine are made from short fibre mixed with which falls through the three scrmeateenrsiaAl other materials Asbestos may be also mado up with rubber for use as jointing weighed sample of asbestos 16 ounces panelling having been placed in the with bitumens for switchboard machine is top box the with synthetic resins and with paints for mechanically agitated in a standardised a variety of purposes method for exactly two minutes and the An important section of the industry industry is is asbestos remaining in each box is weighed In this that engaged in the production of asbestos way the fiber- proportion of longer and shorter fibres insulating materials These include in the sample is ascertained The ised asbestos 85 per cent magnesia more fibre retained in the first box and the less the remainder being asbestos fibre fibre in the lowest the higher the grade and the greater the value of the asbestos mattresses made of asbestos cloth and filled with asbestos fibre or 18 " magnesia so tested or with other material material insulating compo- valiny In this way the seven groups of millexi | siisteinonsandor a plvaatleisny coofntoatihneirng maatsebreisatloss fibre are further subdivided into a number liberised asbestos stiffened into thick sheets of grades Thus in group No. 3 spinning or moulded into shaped slabs or sections and textile fibres there are seven standard grades ranging from the specification and air cell insulating material built up from asbestos of 8-6-1-1 minimum the top grade down to specification of 0-862 paper There are many other valuable uses of asbestos in minimum for the lowest grade in this manufacturing processes which need not be detailed here group when tested in the above way Asbestic or asbestine is a product from the mills in the nature of a residua Risks to Health cfoibnrteaining a very low percentage of short . MANUFACTURING PROCESSES The asbestos whether crude or milled is now ready for dispatch to the factory For textile purposes only the lunger and better fibre comprised in the standard uncontrolled All manipulation of asbestos fibre by hand as in sack filling or emptying blending sweeping and shovelling or mechanically produces dust which if is often in dangerous con centration The inhalation of this dust over a period of time results in the develop- ment of a fibrosis of the lungs a progressive replacement of the essential active func- 2 me 6 " met. : 8 ' * 29e "poget. Oe te Sy ey ee NOR A TELA rTOOP . wwyit ow yy Mt T me eae ees Was anew APOE PSY Sed at PIETR! EOS TPI.. th fy .45 fan Topp ita "te. sontte " " tarde wal fl lor king ing ired Tigh ..nd te with with Iso ag tus * fs - Too 10 toh and ae by ving -- -- - dust velop- passive func- ASBESTOS tioning tissue of the lungs by inactive and useless fibrosis or scar tissue The disease produced asbestosis is therefore in the same category as silicosis which it re- sembles in some respects while differing considerably in others Since asbestos has been of commercial importance for '. scarcely fifty years asbestosis is a modern disease . In contrast with silicosis we cannot trace the history of the baneful effects of the dust backwards over very many years - The first recorded case of asbestosis was that of a patient of Dr. MONTAGUE MURRAY who died in 1900. in the Charing Cross Hospital London mortem . examination revealed extensive diffuse pulmonary fibrosis with no evidence of . pulmonary tuberculosis The records of this case together with the pathological specimens are still preserved This man aged 34 at death had worked with asbestos for some fourteen years and stated that of the ten men working in the cardroom when he commenced he was the only survivor all the others having died at ages round about 30. Little more was heard for a number of years concerning the effects of asbestos dust on the lungs except isulated reports in England and France of high mortality among asbestos workers ami note by Mancitash and Riess " The presener og n usual bodies in the tors of an we'restes we'restes Worker Worker This pantity of information was due to various ranses At that time the investi- gation and prevention of silicosis was occupying the attention both of Govern- ments and of private investigators the use of radiography in the diagnosis of diseases of the lungs was in its infancy and the industry was small as regards the number of workers exposed to appreciable risk Moreover every new discovery . emphasised the importance of silica in the free form as the predominant factor in the production of pneumonoconiosis Thus the real and accepted importance of free as opposed to combined silica in this respect tended to obscure the possi bilities that some at least of the silicates might be equally harmful Although for these reasons enquiry in by 1910-11 the British the Factory Department of Home Office both in Great Britain and in Canada failed to produce evidence of a risk from the dust sufficient to necessitate scheduling processes in the industry as dangerous the Department decided that suppression of the dust evolved in the more dusty processes was required From that date therefore in Great Britain active measures although inadequate by present standards were suppress taken to processes of dust in the more dusty the industry In 1924 however the matter was raised again by the publication of a note by W. E. COOKE concerning the death of an asbestos worker the result in his opinion of extensive pulmonary tuberculosis to- gether with a diffuse pulmonary fibrosis which he ascribed to asbestos dust This case was fully described by Cook and STUART MCDONALD in 1927. A few weeks later H. E. Seilen drew the attention of E. R. A. Merewether to an asbestos worker in whom he had found signs of a diffuse pulmonary fibrosis with no evi- dence of tuberculosis and further investi- gation established the absence of any infective or occupational cause other than asbestos dust Thereupon in February 1928 a comprehensive enquiry in Great Britain was undertaken and the results of this enquiry which was completed in October 1928 and published in 1930 established the presence of a serious risk in the industry In the United States and Canada the Industrial Health Service of the Metro- politan Life Insurance Company curried out a similar survey between October 1929 and January 1931. LANZA MacConnell and F unei published the findings in 1935. These fogether with the valuable study by FULTON DOOLEY MATTHEWS and Hoetz published in 1935 are the only general surveys of the industry In Italy LoviSETTO published in 1930 the results of an enquiry and G. Mussa the results of clinical and radiological examinations Germany possesses valuable data rela- tive to asbestosis based on clinical and laboratory research It suffices to mention the works of BAADER GERDIS 1931 BEGER 1933 BEINTKER 1934 ALWENS KOPPENH^ FER1933 etc. ESSENTIAL FEATURES OF ASBESTOSIS Asbestosis the pulmonary fibrosis of usbestos workers is insidious in its onset irregular in its course and variable in it's mode of termination It is helpful to visualise the discuse as the slow growth of fibrous tissue scar tissue around the bronchioles or smaller air tubes of the Jungs and between the air cells wherever 3 Poe | etion . dus i heath of Departmni US Md Bethesda M for Health bail e e 7) . PEt: dire Oo 0 SIGINT SIGINT SIGINT 4 qc - i{< ~ 3 # ^udi_3019 SA F 310147 310147 ... ... ... -me. ... Telspae funt ? Wailure WailureWailure DICIDICINE NDICEINE of tos al Departmen \ . ASBESTOS o e the inhaled dust comes to rest In contrast to silicosis the former is the shown important site of deposit of asbestos in the lungs as was by GardneR and Crimings While new fibrous tissue is being laid down like a spider's web that deposited earlier gradually contracts This fibrous tissue is not only useless as substitute for the air cells but with continued inhalation of the causative dust by its invasion of new territory and consolidation of that already occupied it gradually and literally strangles the breathing tissues of the lungs Asbestosis is of course essentially local disease and therefore it is only when the fibrosis has obliterates that reserve of lung tissue normally present and encroached upon the remainder which is essential for the normal functions of the individual that symptoms appear Then the appearance of undue shortness of breath on any extra effort draws the worker's attention to the fart that his health is not what it should be The other symptoms of the disease such as cough are equally unassuming and are readily ascribed to some common and trivial cause From this point the progress of the disease is more rapid since it is now encroaching on the remaining sound tissue of the lungs already only just sufficient to maintain the worker in his ordinary daily activities Ultimately if no acute respiratory affection has preci- pitated a fatal termination a stage is reached when the lungs can do little more than maintain life and the shortness of breath becomes extreme To a great extent the outstanding features of the disease are the mechanical effects of this pervasive network of tibrous tissue induced by the retained becomes asbestos dust This prevents the proper aeration of the blood becomes an increas- | ing obstruction to the heart's action anu in very advanced cases the traction on the basal masses of librous tissue which have consolidated with the diaphragm pleura and pericardium still further mechanically embarrasses an already overburdened heart LANZA and MCCONNELL have drawn attention to the radiological evidence of enlargement of the heart in asbestosis cases Usually the fatal issue is determined by the onset of some acute infection with which the remaining undamaged lung tissue is quite unable to cope this is commonly a low grade broncho nia but may be a lobar pneumonia bronchitis influenza or less often a sub- acute tubercular infection There is no evidence that the existence of developed asbestosis predisposes to the onset of such acute infections but if an acute infection does supervene the presence of the asbestosis seriously impairs the chance of recovery Intercurrent attacks of dry pleurisy which are partially responsible for the : considerable thickening of the pleura _ which occurs are coinmon but usually slid only cause slid slid temporary disable--n-ntt In the absence of intercurrent infections the fibrosis may progress to an extreme degree bronchiectasis tubercular cavitation and spontaneous pneu mothorax may occur Ultimately the strain of maintaining the circulation through the partially strangled lungs becomes insupportable and general dropsy with an enlarged liver ushers in death from slow heart failure The most important single clinical sign is that of diffuse bilateral impairment of the percussion note this is slight in degree and associated with a slight sense of resistance It is best elicited by very light and rapid percussion of the back of the chest from apex to base on each side This impairment of percussion note is more marked on the right side The auscultatory signs are variable and depend on the extent and nature of the underlying changes in the lungs on the extent of the fibrosis with its associated pleural thickening the presence of intercurrent affections bronchiectasis tuberculosis and on the degree of compensatory emphysema present In the majority of cases the respiratory murmur is weakened generally more on the right side and often still more at the bases Asbestosis is a dry disease during most of its course in the absence of inter- current infections This attribute to- gether with the diffuse distribution of the impairment of the percussion note makes it ^ silent and unobtrusive disease even more so than in the case of silicosis The symptoms exhibited also closely resemble silicosis and may pass almost unnoticed by the subject for a considerable period since so little inconvenience results Be- tween 50 and 60 per cent of cases of asbestosis complain of slight cough and of undue shortness of breath on exertion 4 . e sf & oe : 8 . . . . id e. 4 ots , . + rs oe 1 Of et SAYol ae hse ee He T TTS EVIE OTA TV - - f ASBESTOS and show luskiness or slight | nineness stages of the diseases are distinctive of the lips which contrasts with the although as PANCOAST and PENDERGRASS general pallor of the face not uncommonly maintain they are not specific for that seen dust DIAGNOSIS In common with other forms ' of pneumonoconiosis the diagnosis of the disease is fraught with diffi culty particularly is this the case in the early stages in the late stages when associated with pulmo- nary tuberculosis and in any stage if the disease is implanted on lungs already the subject of emphysema or if some intercurrent infection has supervened The fibrosis although diffuse and bilateral may be most marked basally and on one side less commonly the bases may be more or less emphysematous and the maximum fibrosis in the central zone of the lungs rarely the is most marked in the upper of the lungs These factors the physical signs presented does the existent state fibrosis portion modify as also of the chest and of the lungs upon which the fibrosis is implanted Radiographic examination of the chest should never be omitted A high level of technique is required which should be standardised A technique which will produce an excellent film and demonstrate adequately silicotic lesions may fail to reveal the asbestos fibrosis entirely or more often will reveal it only partially in the latter case the radiographic picture is not only inconclusive but most misleading The cause of this lies in the fundamental difference between the two types of fibrosis discrete nodular lesions of silicosis and the close network of asbes- tosis This difference is reflected in the radiographic appearances of asbestosis which are revealed typically as a general lack of translucency in the film together head with a fine aptly referred mottling This is to by BURTON WOOD as the ground appearance asso- ciated with it is a shaggy appearance of the cardiac shadow While as is the case with silicosis certain radiographic F10 1 bis - Lung section asbestosis appearances may be looked upon as Radiograms of asbestos workers are typical of the disease frequently modi very puzzling so than in the case fications of and departures froin the of siliosis when it comes to assessing typical picture occur The radiographic the depa of asbestosis present partiappearances of the developed or used | cularly in the earlier stages and also in 5 - 7 wt 2 Esf J pabibesan hy on ohkr . r f = WSpeke ale Lost nd = essere eco Peete 7, : : Concerta sane . . . ir en BEE <sT e ~ sees PREen San} fy ar H ee bee us 4 2 ~ EDICINE dct. mewiredag aye, mewiredag [rena j / mewiredag ENOUGH ENOUGH . | And Bethesda Nise! Bethesda {ae Bethesda vee MEDICINE { SOCK pe SOCK ween Health Health { Lf ! 3 eagtiwne i Public IN 1 Welfare wis Welfare qr and j . f-~ + iva tm a ; Svreota woe 4 al { Department Gino? Department ie Department US MEDICINE i Phi M.J ote Bethesda / Bethesda } YNDILYN SpeKITE ios SpeKITE otaribik " otaribk : Treat 1 : het nr? er it a P f ; Soto a4 hte ist 1 wt 4 ASBESTOS ASBESTOS ; women owing to the shadows cast by j absolute certainty on either physical the breast tissue It is of the greatest | examination or radiological examination to | value in the diagnosis of asbestosis to | alone with the aid of both the pneumono- possess or to have collec cot lli eco tionn of coniosis can be diagnosed with certainty . if present in some degree although not necessarily to an extent sufficient to cause either symptoms or any disablement In very difficult cases where gross tuberculous lesions obscure the picture then careful investigation of the subject's expo- sure to asbestos dust particularly the = yas as to dustiness of the process = a ty Pe tee cs ep SEO EAS : <3 a oue er So ea Fo Coe te ee REISS Beta. oO ne Poo gree ENS eo . my Sle RC et pA 2 sean eh ve LE ee Soa os Yaun;e reRAS Lace oF, a "NSE 44 aq vant engaged in and the length of ex- posure will enable a correct decision to be reached This latter careful study of the actual exposure to asbestos in dust each case a valuable aid in several ways since owing to the immobility of the asbestos fibres once they are occluded in the smaller bronchioles it enables an estimate to be formed as to whether much or little asbestos dust is trapped in the lungs Whether much or little dust is incarcerated in the lungs is of prime importance in coming to a correct conclusion as to the outcome in individual cases particularly those exposure has been centration of dust in which the to a dense confor between one and two years In such cases the radiograms will be negative since there has been no time for the fibrosis to develop but if further radiograms are taken of these cases during the succeeding three or four years the appearance and development of the fibrosis can be watched . . a Fis 2 bis - Lung section silicosis radiograms of cases of asbestosis together with their clinical and industrial histories and the autopsy findings In the light of present knowledge there- therefore asbestosis cannot be diagnosed with Pathological Features As already mentioned the first case of asbestosis in which pulmonary fibrosis was noted at autopsy occurred in 1900 but the first case in which a full microscopical examination of the lung was carried out did not occur until 1927. Records of this case were published by COOKE and HILL and McDONALD The pathological changes in the lungs may be considered under three headings may headings 1 The alterations which take place in the asbestos fibre after it has reached the lungs 2 The reactioof nthse lung tissue and 3 Complications and sequel^ which follow 6 . ve ay i 7 wv 3 2 r r. Hi he 3, i: Z. ; ' 5 : :: + a 7 a * . : y f.3 a : $, y. k q: f at 3: , e f3. : ^' e i 7" rhe awarydes ASBESTOS The asbestos libre as found in the { being about respiratory passages of the workers is || highly refractile fine elastic rod gener- lengths shortest the length of a tubercle bacillus the longest extend- ing across the whole field of the micro- } 13 6 CED exgD =a gas -teson 21 Exirg.2222 esorveace et*@ wwo po gr vamp 33 ty 3232. 33 ^' vA s . ( 7 A10 in, fi TIEDp erat aed 20 5 Der yED 3 - - a RE uae? Aien 30 _@ 29 29 go : a 29 29 tf thy &<>-- se a ; 34 \ \ ae , 5? R. & > 8 as 3a 39 40 Fig 3 - Asbestosis bodles freehand drawings 12th obj @ # cond 41, ally smooth but occasionally showing a sharp saw edge and ends broken at varying angles The fibres are of various scope Short forms are the commoner and naturally are more likely to penetrate to the deeper recesses of the lung The - \ Lazc2hva i Mouth DICINE DICINE Department Department rts Department Department US eae Md . Md iu Reibask~- Reibask~- EDICINE : . Sav . Health s Health a 111TH y . 4 .3 rest G a rs (- * .... { _ z 3 :o4 7 vers ore : ad : Nenditment 1 Nenditment Nenditment "l= Nenditment Nenditment ; 11 : \DICINE i wo bh ~ Md tice. Bethesda wt Bethesda Bethesda ! Bethesda ! t Service Service Mouth Mouth > / * * M ** Edin Edin Hardch Hardch . 2 = Ko Sh ay an 9 2 BSE ES ES ae Steer) 10 ASBESTOS diameter of the fibres has not yet been | determined since they appear capable of splitting longitudinally into finer and finer constituent fibres almost indefinitely Small bundies or sheaves are quite com- mon In the lung these fibres become coated with a colloidal yellow which in the course of time pigment becomes The tissue reaction to the asbestos fibre is dependent on at least two factors 1 TheThe sshharp arp neeneeddlle e shape of the fibre which for practical pur- poses is indestructible and 2 The siliceous nature of the fibre | crenated to form irregular segments giving | the appearance of minute crustaceans | These curiously shaped bodies were first | noted by MARCHAND and RIESAL in | Germany as early as 1906 and later by | Faur and Feigel in 1914 but the latter | was unable to decide whether they were | a crystalline product of haemoglobin or whether they were a direct result of dust | | inhalation no further attention was | called to them until 1927 when they were | described by COOKE and HILL and MCDONALD in Great Britain The last The fibres are for the most part held up at the distal end of the respiratory bronchioles and in the alveolar ducts Here a cellular reaction takes place con- sisting of the accumulation of large phagocytes and the production of a charac teristic cell known as the asbestosis giant cell which like other foreign body giant cells is probably not a cell but a collertion of partially degenerated phagocytes As the disease advances the lymphatics in the neighbourhood become blocked Lastly fibrous tissue is formed round the named suggested that they were alaust - affected affected portions the air passages the certainly a product of the asbestos asbestos GLOYNE finally showed the asbestos libre istani istani capillaris . vi enules the inter4ular 4ular septa the lung and in the pleura 1 lying in the centre of the budy by dissol The fibrosis thus produced is diffuse and ving the colloidal coating with concen- | readily distinguishable from the nodular | trated sulphuric acid whilst under dark- fibrosis produced by free silica Meanwhile ground illumination These bodies have | the asbestos fibres become coated with a never been found in the original asbestos golden pigment which contains dust iron and is believed to be derived from . blood proteins to form the typical asbes- and Bupefgiecanl study study bas made asbestos a thoroughhistological bodies . According to this author the metallic element of the molecule of m^/gnestuin dissolved acid hydrated silicate shell the is The fluids of the body leaving a silicic acid shell form of the nerdies and their power of double refrac- remains is intact absorption asbestus proteins subse- tion needles quently formed by absorption of proteins by the of asbestos and subsequent evakulation in neeille The dispersed from the proteid the form of silicic shell the the ashestos neeille becomes dispersed in proteid sheath of the asbestos body and becomes gradually disintegrated There then occurs resorption by the body fluids of the protrid mass containing the silleje acid Granulous bands of ferric oxide impart to the tosis bodies referred to above It is not known changes known how long all these take bring about to but GarDNER and C M- in experimental | experimental that MINGS hhaavvee shown in animals amall asbestosis bodies appear fibrosis | at the end of two months but fibrosis in the walls of the bronchioles was not noted until disease end recognised 500 the end of two years the At the disease can of about be recognised | asbestos bodies their brownish colouring Koppenh^rer 1935 considers that the sheath to those parts of the lung most closely affected by opposes Begen's Begen's asbestos Begen's opposes Begen's theory asbestos bodie formation Srybius and Broden 1937 in a detailed study of ast~-rstosbodies contained in the lungs of a worker who died of asbestosis arrive at the following.con- following.con- clusions in regard to the mechanism of formation of the asbestus bodies The organic substance of the latter is composed of proteid matter The most Important element per cent the shell of | the astrusios body is iron oxide The inorganic part of the shell does not conie from the inlated dust but Is of endogenous origin coming fruin the body and principally_froin principally_froin products piamrat In the outbreak Abrosis esentialy causal relatthieon | the of the two processes fact that various derived fruin the blood light of this formaftorimaotinon between la perhaps doubtful in view of the authors have found these bodies in lungs ut persons not suffering from asbestosis and even in lungs free from Abrosis On the other hand it is well known that the formation of asbestosis librosis should be connected with the presence lit pul- lung of asbestos needles and their action on the pul- inonary tissue On the basis of Interstillal localiztion of the Obrosis at the outset and its later extension mechanical irritation and the injuries caused by the long rigid needles as a factor in the formation of Abrosis The distribution of the Abrogis moreover seems to primary influence intgration the TACK formation 1bodi9es37asbestos abcocdoiuenst refterhse alltea of similar which justify the hypothesis accords a to respiratory movements on the of large asbestos needles in the lunes ) in asbestos of mechanism of *to designates presence alltea bodies found in silicosis witwhith partiparticular cular mention of their occurrence in a case of typical nodular AbrosiIS le lungs well coal lungs TYLscore further states that similar formations have been DUNN in lungs in workers TYLscore consider- able number of subjects who died of heart failure arterio- particularly 10 ecierusis) without of rbeumalus abu exposure to quat The .ron content and seeming with pui- common connection local monary congestion and the liberation of blood Iron raises the question as to whether the iron of the related asbestos body may not be so and whether congestion may at least least in part favour produc tion of all such bodies asbestos bodies silica bogien and similar formations 8 2 x . : 45. if ie < bE " be aN ik iy ci. (. i 6: t1. I:a i : a 4 & : ? 4 >. ce +6 ASBESTOS by the naked eye It is probable that the disease takes longer than this to develop in man any rate to an extent sufficient cause radiological and clinical signs When the lungs are examined by the naked eye after death they are seen to be The number of cases of the latter far described is small and it is not yet estab lished that there is any aetiological connection between the two diseases thickened large and densely fibrotic and the pleura covering them with plaques of old pleurisy Often the lung is completely adherent to the chest wall and in advanced cases to the diaphragm with the formation _ of a thick and extremely dense layer of fibrous tissue | This anchoring of the lungs particularly to the diaphragm together with the genes increase of fibrous tissue in the lungs which makes them firmer than normal is the probable explanation of a curious elinical sign sometimes seen E. R. A. Mere- WETHER noted that in some advanced cases the apices of the lungs may be easily seen rising in the sunken clavicular areas with expiration and descending with inspiration On cut surface the characteristic appear- ance is that of dense black polygonal areas of asbestos cellular debris and pig- ment corresponding to the secondary lobules of the lung and surrounded by thick bands of lobular connective | tissue Generally there is a reddened background of terminal bronchopneumo- nia in the less affected portions of the lung There are few naked eye signs of disease elsewhere Of the complications and sequela of pulmonary asbestosis four are outstanding 1 Purulent bronchitis 2 Bronchopneumonia 3 Pulmonary tuberculosis and 4 Emphysema with occasional rupture of emphysematous bull^caus- ing spontaneous pneumothorax The purulent bronchitis may be of long standing The bronchopneumonia is practically always a late event and recovery very rare The pulmonary tuberculosis is chiefly of the caseous type with little or no sign of repair and the emphysema compensatory to the fibrosis In addition to these four main complica- tions may be noted two which are less common 1 Dilatation of the bronchial tubes resulting sometimes in what is known clinically as dry bronchiec- tasis and 2 Carcinoma FIG 5 - Infra photomicrographs of the asbestosis lung BRIDGE and HENRY have proposed that cancer in order to be classified as of industrial origin must fulfil the following two conditions 1 that the incidence- rate in the occupation under review should exceed that in the general population to a significant extent and 2 that in the occupation concerned there should be sufficient association of a worker with a substance proved experimentally to fh . ee wetoO ee he artee ee mee 6 caenen + ee Me cee = sristes +t, ox 7 + TES,ft) Cee Bort { oer, -~* ca CJ a - mm - ce Item ), e rN madm, ( af sonet Nee 93 I. THINM one tes . Rtegnr Palbe Weling tt ; HIE 110 f^ut ) o . stardik al AY Donarimn US ZDICNE And %, Bothand Ls HashService HashService pe eorast HashService EDICINE co Pubic we Walace ~e. Walace . And NOLES ~ vet A DICI . 2 4 she wets t ASBESTOS . postulates |j | h^vecarcinogenic properties These two cannot yet be regarded as having been fulfilled in the case of the of exposure determine the incidence rates in different processes in the industry Exposure to asbestos dust for less = AY than five years can result in the develop- -| ment of a degree of asbestosis sufficient } to cause death Commonly however cases of definite asbestosis are not disco- vered on examination within five years of commencing work although a few are found Among those working who have been employed for between five and ten years in the absence of preventive measures the incidence rate is appreciable and after ten years of such employment a steep rise in the incidence rate occurs The incidence rates for the periods of employment 0-4 years 5-9 years 10-19 years and 20 years and over amongst 1,512 workers examined by the British Silicosis and Asbestosis Medical Board were proportionate to the figure 1 5.6 30.4 53.2 Although the incidence rate thaue low amongst showing brous those with less than five years exposure is ensin and Fig 6 -- Lung section stained with haemtoxylin haematoxylin haematoxylin haematoxylin so such exposure exposure may be by no means van Gieson The . negligible fact is as suggested above surrounding asbestos fundies that work in a dense concentration of asbestos dust over a comparatively short period will lead inevitably to the development of a profound fibrosis provided that the worker lives long enough for it to develop As GARDNER and CUMMINGS have shown the fibrosis takes time to appear in fact there is a lag of some five hundred days before microscopical signs are de- monstrable it is much longer before the fibrosis matures and clinical and radio logical signs are apparent Correlation of the facts concerning particular cases of asbestosis will use concerning the relative dustin im processes at which y worked inanis the conclusion that this period of maturation * of the fibrosis is not reduced below a certain minimum period however high the concentration of dust in the air breathed may be Fio Fio 7 7 - SectionSection asbestos lung unstained unstained showing showing asbestos industry but there evidence to warrant careful in the future - is sufficie sufficie observation observation THE PROBLEM OF ASBESTOS DUST Within certain high and low limits the concentration of asbestos dust in the air of workrooms is the determining factor in the onset of the discase and also within limits concentration of dust and length Similar considerations concentration show develop- below below a certain concentration develop- develop- ment of a disabling degree of asbestosis will not veen in the space of an verage working ina tune It appears therefore that a certain certain " minimum producing amount must as it may be called of asbestos dust must be in the lungs in order to trapped a disabling or serious amount of cause fibrosis | and also that a certain " maturation " | period must elapse before that amount of fibrosis is developed developed | | Fatal cases of asbestosis have resulted from exposure as short as two years or 10 . ray Ce 9 tN rate rub . ws MRE eat ger * tw r Suit ts ae ry . Si , ... ..it en Af .al -is -is na zat tysee all ul anf **** ASBESTOS . even a little less although the fatal issue may be postponed for many years | of It is important to consider what is the amount dust which will produce this result or conversely what is the amount practical of dust which from the view can be inhaled with point of impunity Efforts are being made notably by American investigators W. B. FULTON and others to establish in terms the concentration of dust in the air which can be permitted with safety In Great Britain the problem has been approached from a different angle that of determining what processes are safe rather than an exact figure for concentration of dust E. A. Merewether came to the conclusion . that in order to prevent the full develop- ment of the disease among asbestos workers within the space of an average working lifetime it is necessary to reduce the concentration of dust in the air of workrooms to a figure below that pertain- ing to spinning at the time over which these cases were exposed - Particulars of cases seem to show that with exposure to high concentrations of dust the minimum period of time which must claps between the commencement exposed exposed the produtivos produtivos produtivos serious degree of dostosis dostosis is approximati ly seven made up of the period of exposure during which the taken producing amount of dust is taken into the lungs and the maturation period during which the fibrosis develops periods of course overlap This period of approximately seven " years the asbestosis production period as it may be called is the minimum and few cases mature in this period in succes- sive years however depending on the dustiness of the process engaged in more cases mature In the more dusty processes in the absence of adequate preventive measures the asbestosis production period is commonly eleven years ' When asbestosis of serious extent has unduly matured the worker is breath on any extra exertion short of has has a little cyanosis of the lips and also a little dry cough mostly in the mornings He finds himself disinclined to climb stairs or walk up hills but still remains at work and usually is not anxious about the state of his health The amount of disablement produced is surprisingly slight for a number of years This is partly due to the character of the disease and partly to the nature of the work which in the majority of processes in the industry in which there is a risk of asbestosis does not involve much physical exertion Those affected may and often do continue at work with occasional inter- missions latterly due to exacerbations of bronchitis etc. until the condition is far advanced although increasing inconve- nience from shortness of breath is expe rienced Usually these cases cease work a year or more before death but sometimes a terminal bronchopneumonia or other acute infection cominences while they are still at work and there is no long period of invalidism It is remarkable to what extent the lungs can be affected by asbestosis and yet life in a fair degree of comfort remain The reserve is however so slight that the addition of any burden to the system in the form of a disturbance of health which would only slightly inconvenience a normal person may overcome the remaining resistance and precipitate a fatal outcorne For these reasons and from consideration of the features present in the recorded fatal cases the view must be accepted that the existence of even a moderate degree of asbestosis is a serious and ever present potential risk to life Since a worker with developed asbestosis may still remain at work and be little concerned as to the state of his health the question may well be asked " Is asbestosis ^ serious disease " To this question unfortunately the answer is emphatically yes Asbestosis and TuberculOSIS 1 The Industrial Hygiene Division of the National Institute of Health United States has examined 1937 543 persons in asbestos textile plants An analysis of data shows that the maximuni concentra- tion of asbestos dust to which workers may be exposed without contracting asbestosis is in the neighbourhoud of 5 million particles per cubic foot and it was determined by appropriate technical Measures of control that the dust concentration could be reduced per cubic fool to less than 2.5 million particles Proof of this is now not difficult to find as examination of data from the known fatal cases and comparison with similar data concerning fatalities from silicosis provide ample evidence Fatalities from asbestosis and asbestosis with tuberculosis have now been reported from a number of countries Of these the British figures are 11 Education Education Hadirh of Department US And Beth 850 at! ae bil PNP , : ol ar OD fubie EDS se OOP tee Alae my Alae . oe and . STrT eeureg at 08 s Riedl) wo. Hane ... Man~-tmae 118 ene et o- eo. Healy TDICINE TDICINE Pulibe Welare and Pituramen Montch of d Oncnew ASDESTOS the most complete since the disease has been compensatable since 1 June 1931 The following figures are abstracted from the Annual Report of the Chief Inspector of Factories for 1935 TABLE 1 Diarase Num- Num- ber deaths Aver- age age death Duration of employment in years Lon- Shor- Aver- Kest Shor- tat | age f Silicumis , . 2 Siliensia tuberculosi with . tuberculosis | 311 391 55.8 | 62.0 | 52.4 67.0 Asbestosia . . Asbestosis with tularrentiosis . 52 41.9 30 | 37.1 27.0 13.0 1.3 35.1 2.0 | 38.7 1.5 | 12.5 0.8 9.5 cy Table 1 gives particulars of 702 deaths from silicosis or silicosis with tuberculosis and of 82 from asbestosis or asbestosis TABLE 2 It will be observed that 1 2 * 3 - 4 The average duration of employment in the asbestos industry suf ficient to cause a fatal degree of asbestosis was 12.4 years as com- pared with 35.1 years for all cases of silicosis The actual average length of exposure to asbestos dust was however still less The shortest length of exposure to asbestos dust which ultimately caused death from fibrosis of the lungs was 1.5 years Asbestosis is comparable with the most serious silicosis risks with will respect to length of exposure which cause a fatal degree of fibrosis Although the numbers in the as- bestosis group are small it will be noted that in 36.6 per cent the disease was accompanied by tuber- culosis while in the silicosis group 55.7 cent were accompanied by tuberculosis suggesting a less close association between asbestosis and tuberculosis than is the case with silicosis and tuberculosis Aver of Duration employment | Poliery Silleoris with Sandstone tuberculosia , Sillcosts with Grinding Luberculosi mies Sillcosts . .] Siliensis with fuberenfuxiN Sandblasting Sitleusis Silicosis with tuberculosis . Manufacture of scouring powders Silleusis. .. Sillensis with tuberculosis . Miscellaneous Siliconis . . Silicosts with tuberculonIN Ln 159 | Sale 10 1 51.1 78 56.5 RAT 58.9 620 67.0 57.0 58.0 Sa 09.2 5.0 | 36.1 3.0 38.3 10.0 | 15.3 | 26 56.561.1 262.60.0 18.0 31.J | | | re 58.1 50.0 31.5 31.5 15 | 11.5 . | 29.0 4.0 10.7 16 11.111.1 20,0oe R. 1.7 37.0 11.5 10.B 25 33.7 65.0 28 | 49.0 | 58.0 2.3 2.0 6.0 9.0 9.0 6.1 2.5 5.6 with tuberculosis In table 2 the cages tuberculosis of silicosis and of silicosis with are distributed according to the industries concerned Further confirmation is found in the after history of the 95 cases of asbestosis and the 5 sns-2 of asbestosis with tuber alosis found is R. A. MEREWETHER in * lue original quiry in 1928. Of these . 100 cases although a number have migrated from the industry and have been lost sight of 23 are known to have died 12 from asbestosis 9 from asbestosis with tuberculosis and 2 from other conditions in both of whom a considerable degree of asbestosis was found on autopsy Of the remainder a disabled on number are account of partially or wholly the disease As mentioned previously the risk to life associated with asbestosis is a complex one Primarily the fibrosis and the re- sulting mechanical embarrassment of the pulmonary circulation develop in step with each other The supervention in an indi- vidual with asbestosis therefore of any disease which adds to this strain brings with it a greater risk to life than would be the case in a normal person Amongst such diseases infections of the respiratory tract and especially bronchopneumonia and tuberculosis hold first place The risk from tuberculosis requires special consideration because of its ac- cepted importance in asbestosis as in silicosis and because of its infective nature 12 pee. + oan tone, Bh Fe ee PE waNT Ge 2 Ciaeaenet ios tach aL halite ASBESTOS The interaction of asbestosis and tuber culosis is of moment in determining both the real importance of asbestosin as an _ relationship preventive industrial risk and also the scope and pro- bable effectiveness of projected measures There are a number of aspects to this relationship which have to be clearly defined as yet the data are insufficient GARDNER and CUMMINGS as a result of their experimental work on guinea have established a point of the greatest importance namely that a primary tuber- culous infection is influenced only to limited degree by inhaled asbestos and that the tendency to healing by fibrosis is marked They emphasised the contrast in this respect between the effect of asbestos generalised and of free silica with which the tendency was overwhelmingly towards the produc- tion of chronic tuberculosis of the lungs and viscera These same workers found in another group of experiments where the tuberculous infection was implanted on to an existing asbestos fibrosis that the stimu- lating effect on the tuberculous infection was more marked than when the infection and inhalation of asbestos were instituted simultaneously but the ultimate outcome had not yet been observed They also asbestos stated that the combined action of dust and tubercle bacilli in the lung pro- duced more fibrosis than did either agent acting independently In a subsequent paper BURTON Wood and GLOYNE reviewed a series of 100 cases of asbestosis which had been under their observation In this group they found 30 cases with pulmonary tuberculosis 21 being active and 9 obsolescent They pointed out that the group with obsolescent tuberculosis emphasises the fact that obsolescent tuberculosis in the human is not necessarily reactivated by asbestosis In the series of deaths analysed above it was noted that asbest WAS ABSU- ciated w cuberniosis in muwit lower percentage in was the case with silicosis 1. Rush Saul1 in un analysis of 71 cases of asbestosis notes the presence of tuberculosis in 10 one of which showed a healed miliary tuberculosis Although it is not possible yet to answer categorically 1 Does the inhalation of asbestos a antecedently b coincidently c subsequently to a tuberculous infection favour the development of the tuberculous process or not and 2 What is the effect of the presence of a a slight b a moderate c an advanced degree of asbestosis on i the implantation ii the development of a tuberculous infection these observations suggest that whatever the added risk to asbestos workers from pulmonary tuberculosis may be and there appears to be some it is less than that associated with silicosis It is worth re- cording that in two cases signs of both silicosis and asbestosis have been found at autopsy in one of which there was also pulmonary tuberculosis PREVENTIVE MEASURES The risk from asbestosis in the asbestos industry is no less grave than the most serious risks from silicosis in the silicosis producing industries The preventive measures necessary therefore will be extensive and stringent The essential is dust suppression in all processes to a safe level which level may be determined by refer- ence to a definite concentration of dust pro- in the air of the workrooms or by reference to the amount of dust produced in a cess which been shown to be sale There advantages and disadvantages associated with each of these standards but space does not permit of their discussion here In Great Britain the second of | these alternative methods was adopted A Joint Committee of representatives of the Factory Department of the Home Office and of the Asbestos Textile Manufacturers agreed on a practical standard based on MEREWETHER'S suggestion as to the relationship between the safe level of dust concentration and that evolved in spinning processes This Committee concluded on the evidence then available that For practical purposes the conditions arising from flyer spinning ! carried on without exhaust under good general conditions may it seems to the Committee be taken as the dust datum If therefore a particular | | process appears to give rise to dust in excess | of that associated with such flyer spinning the Committee regard the need for preventive | measures as established emulations 1 The dust production in the safe level and the ring spinning is above vision of local exhaust require the prom ventilation to the process 13 Ay acLyy| al Sorsgna US ... Sates Heth oo eval a wane oor siete al one Dramo .. and Bobks TL Se .? dee North v n 1914 1914 Me Pulbe es \ Welare and ed bike ZZDICIDNE ICINE ZDICINE ob kt ASDESTOS In March 1932 a comprehensive Code all of Regulations designed to suppress the dust produced in processes to at least the level of that arising from flyer spinning carried on without exhaust under good general conditions " came into force These Regulations apply the following principles to achieve this standard 1 Ap- plication of efficient localised exhaust ventilation at dust producing points 2 Sub- stitution of enclosed mechanical methods for hand conveyance and for dusty hand work generally 3 Effective enclosure of producing machines and plant 4 Substitution of wet methods for dry 5 Elimination of certain dust producing appliances 6 Effectual separation of processes to prevent unnecessary exposure to dust 7 lise of sacks of close texture for internal work in the factory and cleaning of them by machinery 8 Efficient cleaning systein 9 Precau- tions to prevent dust from asbestos in storage chambers or bins entering the workroons 10 Regular examination and testing of ventilating plant dust settling and filtering apparatus not to he allowed in workrooms 11 Breathing apparatus of approved type to be provided for per- for asbestosis and asbestosis accompanied by tuberculosis for all workmen employed at any time on or after May 1931 in any process specified in a comprehensive schedule In Germany the Order of 16 December 1936 and in Danzig the tinder of 11 March 1937 grant compensation for serious asbestosis feeling workers ming within accident IInsurannce surance legisinti In the United States the law of 26 Marri 1935 passed in North Carolina provides for compensation of asbeg- tosis in a certain number of industries The problem of compensation for asbestosis was considered by the Correspondence Com- mittee on Industrial Hygiene of the Inter- national Labour Office which at its last meeting in October 1935 decided to recommend to the Governing Body the following formula for inscription in the international schedule * Asbestosis with or without pulmonary tuberculosis provided that asbes- tosis is an essential factor in causing the " resultant incapacity or death when occurring recognised amongst workers engaged in industries or processes under national law or regulations as involving exposure to the risk of asbestosis The Committee made the further recommendation that it is advisable to recommend that those countries which so far are without adequate knowledge of the question should carry out in the near future the requisite enquiries and research for determining the extent of the occupational sons employed in certain operations The Regulations also prohibit the risk involved employment of young persons under the BibliograpHLY age of 18 in the most dusty processes In order to achieve the object of the and Regulations problems of ventilating en- gineering of the utmost difliculty had to be solved particularly on the textile side of the industry where the application of local exhaust ventilation other me- thods of dust suppression of a high stan- dard to operations in which the necessity for it had never been envisaged before was required Other preventive measures in force in Great Britain include the control of the disease by periodical medical examination of the workers by which those unfitted prevented by health reasons are from entering the industry and cases of asbes- tosis and of pulmonary tuberculosis are detected at the earliest possible moment A practical maxim of the greatest value that is every translation of fiberised asbestos in the factory produces dust which if not controlled is dangerous BECER in Virchow's Archiv Vol 290 1933 pp 280-353 Cook W. E. Brit Med S. 26 July 1921 p 147 and 3 Dec. 1937 p 1021 Fulton W. B. Dooley A. Matthews J. and Houtz R. L. Dept. of Labour Pennsylvania Special Bulletins No. 37 1 Oct. 1931 and No. 42 20 Sept. 1935 Gloyne S. R. in Tubercle 1929 p 40 Lancet 1932 Vol 1 1351 Tubercle 1933 p 208 445 483 550 1935 p 5 HOME OFFICE Report on Conference between Employers and Inspectors concerning MethDust in Asbestos ods for suppressing Textile Factories H.M. Stat Off London 1931 Koppenn^...ferin Arch f Gew Path 1. Gew Hyg Vol VI 1935 No. , pp 38-63 Berlin Lanza A. J. MacConnell W. J. and FernEL W. U.S.A. Publ Health Rep 4 Jan , 1935 Compensation for ^ sbESTOSIS Great Britain was the } first special legislation relative country to pass to compensation ' Among the States which accord compensation provisions for asbestosis by blanket coverage there are some in which the general coverage Law contains special concerning asbestosis iminis Law of 16 March 1936 Indiana Law of 6 March 1337 l'ennsylvania Law of 1937 14 Thr o. . t bee! TT aes ant 2 ee oe . ateao ASBESTOS LYNCH K. M. in Journ Amer Med Assoc 11 Dec. 1937 pp 1974-78 Chicago MCDONALD S. p 1025 Brit Med J. 3 Dec. 1937 : McPuzzters S. B. J. of Ind Hyg and Tos April 1936 p 229. Boston MEREWETHER E. A. The Occurrence of Pulmonary Fibrosis and Other Pulmonary Affections of Asbestos Workers Journ of Ind Hyg May 1930 p 198 and June 1930 p 239 Memorandum on Tuberculosis * Tu- bercle Nov. 1933 p 69 Dec. 1933 p 109 Jan. 1934 p 152 and Price C. W. Report on the Effects of Isbestos Dust on the Lungs and Dust * Suppression in the Asbestos Industry Stat Off London 1930 H. M. SHULL J. R. Radiology Sept. 1936 p 279 Syracuse U.S.A. SUNDIUS N. and BYGDEN A. in Arch J. Path u flyg No. 1 pp 26-70 Berlin Vol VIII 1937 Figs 1 bis and 2 bis are taken from lung seations stained by E. H. Sarsons of Birmingham University with his modification of Mallory's method Figs 3 to 7 are taken from various publica- tions by S. Roodhouse Gloyne Dr. S. R. Gloyne London and Dr. E. R. A. Merewether Biriningham oe 6 ee ae ee e ee . cee ne ew nw we en e e em er e ee e we e 15