Document pe5yx1zvVJ8nkG6J068N7EDxk

. THE . DISEASES OF OCCUPATION Donald Hunter *. II#**'*--'- -London ' ` . " " \ v V - t /(') > "i' English University Pre^h. ^ }';! /. /f? 1 ` ^^ ' ' *1955. "o ' ~* . . v * *i; ; V* THIS DOCUMENT WAS NOT A RECORD OF ` PPG INDUSTRIES, INC. DID NOT COME FROM / / IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES. INC. LL S J J/ .* '**%**e-S-'.y.V+ -: 1 H 186 THE DISEASES OF OCCUPATIONS Description of disease or injury. Nature of occupations 38. Tuberculosis (cant.) note- HOT < occupation involving? (b) in attendance upon or persons suffering- berculosis, where the-1 such attendance arises I son of physical or tnent firmity; (c) as a research worker eng m t \` 1 in research in connexion..-' tuberculosis; {d) as a laboratory worker," oiogistor post-mortem1 where the occupation ; working with material, v is a source of tuberculous faction, or in an occup ancillary to such employ First Schedule, Part 2 Pneumoconiosis. Fibrosis of the lungs, due to silica dust, asbestos'do dr other dust, and including the condition of the lungs known as da reticulation. .. 1. Any occupation involving-- (a) the mining, quarrying or working of silica rock or the workings dried quartzose sand or any dry deposit or dry residue of; or any dry- admixture containing such materials (including u occupation in which any of the aforesaid operations are 1 out incidentally to the mining or quarrying of other mine to the manufacture of articles containing crushed or ground! rock); (b) the handling of anv of the materials specified in the for subparagraph in or incidental to any ot the operauons-r tioned therein, or substantial exposure to the dust arising^ such operations. 2. Any occupation involving the breaking,'crushing or grinding Hint or the working or handling of broken, crushed or gmund flintfjj materials containing such flint, or substantial exposure to the dust: from any of such operations. 3. Any occupation involving sand blasting by means of compressed 2 with the use of quartzose sand or crushed silica rode or flint, or sub exposure to the dust arising from such sand blasting. 4. Any occupation involving-- (a) the freeing of steel castings from adherent siliceous subs (A) the blasting of metal castings to free them from adherent.: HEAL . jtheswar j-uthenwar t.v dust ari *>. Any itasual exf *. Any -x i. hv ms she dust i. Any *<r. L j. Anv : ;is t "y'.sini. la c-m * b GG 15333 3 .A 1 1 ' TH 0007324 | Lure of occupation ation involving: ttendancc upon a person jersoos suffering from tuulesis, where the need for i attendance arises by resof physical or mental in* ity; research worker engaged -search in connexion with rculosis; laboratory worker, pathstor post-mortem worker, -e the occupation involves ing with material which source of tuberculous inin, or in in occupation iary to such employment. silica dust, asbestos dust C lungs known as dust- ca r the working of t orv^. / residue of silica materials (including any d operations are carried ing of other minerals or crushed or ground silica verified in the foregoing of the operations merl in the dust arising from rushing" or grinding of hed or ground flint or sure to the dust arising neans of compressed air :k or flint, or substantial ig. ;nt siliceous substance: cm from adherent sili* ^HEALTH OF WORKER IN TWENTIETH CENTURY 187 - ceous substance by means of any abrasive, by a blast of eom- I - prl air, by steam or by a wheel; s^ 0f iron castings with the use of siliceous materials i r as a facing powder or parting powder; substantial exposure to the dust arising from any of the fore* going operations. ~ _ "Any occupation in or incidental to the manufacture of china or '' J-Jvearthenware (including sanitary earthenware, electrical earthenware and f ; tS^cartbenware tiles), and any occupation involving substantial exposure to I v^igthe dust arising therefrom. \ 6."Any occupation involving the grinding of mineral graphite, or subt ^'^&Bntial exposure to the dust arising from such grinding. occupation involving the dressing of granite or any igneous P ^-^rock by masons or the crushing of such materials, or substantial exposure i - jti$?to.tbe dust arising from such operations. Any occupation involving the use, or preparation for use, of a grind.v-Ljajtoonne, or substantial exposure to the dust arising therefrom. Any occupation involving-- (a) the working or handling of asbestos or any admixture of asbestos; the manufacture or repair of asbestos textiles or other articles containing or composed of asbestos; v^5%t(c) the cleaning of any machinery or plant used in any of the fore going operations and of any chambers, fixtures and appliances / . fbr.the collection of asbestos dust; (d) substantial exposure to the dust arising from any of the fore* |2fcW going operations. . . *Any occupation involving-- IS* (a) work underground in any coal, tin, slate or haematite iron-ore mine; the working or handling above ground at any coal or tin mine of minerals extracted therefrom, or any operation incidental thereto; js?(c): the trimming of coal in any ship, barge or lighter, or in any w dock or harbour or at any wharf or quay; ^(<0 the sawing, splitting or dressing of slate, or any operation inci^ dental thereto. tByssbmu. Employment for a period Of periods amounting in the ,'*t> not less than twenty years, in any occupation in any room process up to and including the carding process is performed s^tones in which the spinning or manipulation of raw or waste cotton Inn. -rzE*Health and Welfare of the Miner contrast with the early years of the nineteenth century, when it was "* m admitted that the State had either a right or a duty to inter- . Hi C .hj-; 5. p 2h .3 2*L * ^ 5M S. li Z4 V?r CG 15334 *v **> I ................... ? 4'l W ^ l i V u* ; _ it-' MV; . 3 - -. _ j " >> * 874 THE DISEASES OF OCCUPATIONS 5ri*---T-Ns: - '* . . permit . mcanin not onl rsspirat (A.D. 70 unquenc magne p -- through throughc industria --jons. a fij Sources Canad come3 fro Zealand, t collective r . differ frorr fSSO?- .but resemi Their valu .long and sh Fig. 388.--Patient* with Silicosis at Timmins, Ontario, breathing Alumiaiuia^ Powder from an Experimental Treatment Chamber (By amruty / Or. H. W, Jacob) r-de%m ---- rjn-.-v.ii Asbestos and Other Fibrous Silicates The question as to whether silicates are toxic when inhaled has bear.^lpj^.^. much debated since Jones (i933)-put forward the view that seriate: potassium aluminium silicate, is the cause of much industrial silicostt-His ^:'^ ; view has received but little support. Certain silicates are noxious,- and thery^V... chief of these is the group of fibrous mineral silicates known as asbeatnsiTo'^^iv a less extent talc produces a fibrous reaction in the lungs; sillimaniteand^i^w^ glass wool seem to be harmless. (a) Asbestos Asbestos is the name given to a series of minerals composed ofsiffeatesZvtiC'rr,*'.; of magnesium and iron. It is sometimes referred to as earth flax; stone&te or mountain cork. It is silky and fibrous in form, and this fibrousttrucno*.^, determines many of the characteristics of asbutom, the disease caused inhalation of the dust. Asbestosis is a more serious disease even than *Sv^v* cosis, but it is far less prevalent (Stewart, 1947). History ofAsbestos On a small scale, asbestos was made into cloth at least 2,000 years Herodotus (450 B.c.) relates how the Romans mined it in the Italian and Ural Mountains, using it for enshrouding corpses before ^ properties c commerce i. This has th , derived also, the mdse irni . short far spi; and heat thar and usually r. of iron, NaFe its prevalent c in Cape Provi - workable quar initial letters o it was first wo and tremolite. Uses Capable ofl ment, rubber electrical, build; dcts. These in and corrugated c cements, tiles an asbestos is usua, acid-resisting fil; TC- 1 . a1 T hei ^ -* 15335 | BB 0007326^^* `-V. NS ~ir.v / Z- 4-\ .0, breathing Aluminium t Chamber whit> inhaled has I'l-m le view that scricite, a industrial silicosis. Ik*' es are noxious, and the i known as asbestos; To lungs; sillimanitc and.. ___ ___ S composed of silicatesis earth flax, stone flax i this fibrous structure , the disease caused by. disease even than si'i1 t least 3,000 years atro. d it in the Italian Alps es before cremation to THE PNEUMOCONIOSES 875 .Spjpenmt of easy collection of the ashes for burial. They named it amianthus, leaning without miasma, undefiled or incorruptible. Pliny (aj>. 50) refers ynot 1only to difficulties in the weaving of asbestos, but also to the use of lintors to avoid the inhalation of dust. Strabo (30 b.c.) and Plutarch' 1.70) refer to the wicks of the lamps of the vestal virgins as asbexta, the iquencbable, inextinguishable or inconsumable. It is stated that Charle- e possessed a tablecloth made of it, which was cleansed by passage iugh fire. However, although the occurrence of asbestos is widespread ughout the world, it is only since about 1890 that it has been used for industrial purposes. In 1880 the annual world production was only 500 tons, a figure which had risen to 1,300,000 tons by 1951. Sources and Varieties ^"Canada produces 65 per cent of the world's asbestos. The remainder comes from Italy, Cyprus, Finland, Russia, South Africa, Australia, New O Zealand, the United States of America and Peru. The term asbestos is a collective name applied in commerce to a variety of silicate minerals which differ from each other in chemical composition and physical properties, but resemble one another in their finely fibrous nature and flexibility. Their value depends on the facility with which they can be split Into long and short flexible fibres, their resistance to acids and their insulating properties with respect to heat and electricity. Most of the asbestos in mmerce is fibrous serpentine, especially chrysotile, 3MgO.2SiO5.2HjO. b-This has the longest and strongest fibres and can be spun. Asbestos is fSCderived also'from the hornblende (axnphibole) group of minerals, of which 'Sjjthe most important are crocidolite and amosite. These consist of fibres too short for spinning, but more stable chemically and more resistant to acids d heat than chrysotile. The hornblende varieties contain less magnesium td usually more aluminium and iron, crocidolite being mainly a silicate bf iron, NaFe(St03)jFeSiOs. It is also known as blue asbestos, in allusion to L;J its prevalent colour, and as Cape blue, because formerly it was mined only in Cape Province, South Africa. Amosite, (MgFe)O.SiOlt-which occurs in {workable quantities only in the Union of South Africa, is named from the s anhial letters of Asbestos Mine of South Africa, the title of the mine where fit was first worked. Other varieties are actuiolite, Ca0-3(MgFe)0.4Si0,, ;and tremolite, Ca0.3Mg0-4Si0t. ' r.Uses Capable of being spun into yam and woven into doth or of mixing with lent, rubber, resin, plastics or graphite, it prorides the engineering, lelcctrical, building, chemical and other trades with a variety of useful pro ducts. These indude a vide range of insulation products, as well as flat md corrugated cement sheets for building work, and also roofing shingles, rcements, tiles and fireproof paints. In brake linings and clutch facings the sbestos is usually reinforced with wire threads. Asbestos is made into id-resisting filtering cloth, imings for chemical pans, valve packings. r:1 *. X 1 -* 1 ;1 C-G -1533b il: 1 |_Jb~0007327"" -t 3; '5* .^#yv 876 THE DISEASES OF OCCUPATIONS *-*^5*1 gaskets, jointings and lagging material for steam pipes, and is used fo^-?,y_t coating the bulkheads ot ships and manne piers. Long-fibred asbestot^^^^^f which can be spun and woven into textiles, is used for fire-fightihg firemen's helmets, sheets and ropes, theatre safety curtains, boiler mat^;S%ggj tresses and for the coverings of welding rods where it acts as a flux.. Mining, Crushing and Disintegrating Asbestos is mined both in open pits and by underground methods!^ After blasting, the longest asbestos fibres are separated from the mother^^g^r i rock by cobbers. These men are exposed to much dust because they .do tin VJ?: V. --*.**- *. 'j-X sSSp'.v.* ./> -A- Fic. 389.--Stripping *n Asbestos-carding Machine before a modem type of'vt^sifSSy { Exhaust Ventilation was applied locally . (4y aururr of BnmJt BHttnf md Asbtrtoi, Ltd.) .*| their work by hand with a cobbing hammer. Raw asbestos in crude and;**s&-'. j fibre form is imported into Great Britain and stored in sacks in opeft ^jf;-" sheds. The sacks are carried to a rotary milt and opened, two or three ac '-.-,71.^ * a time, by hand. This process is dusty. The material then passes by vacuum.'-7^- suction into a closed-in machine which delivers flocculent, soft, fibrourc^gv material, free from grit. 0 Carding and Card Cleaning 'JiSSC*. - ,,. . . For the manufacture of yam and cloth, cotton is often incorporatedwith the fibre before carding. The carding machine consists of large, fast- ;':vf/_ running cylinders, covered with innumerable minute wire points to ensure . 7^. . that the"! is receive and clear Spumisf -SpuHl *- weaving i rusting ce boards, a cement"Sr secure the becoming out upon i room. Sul "polishing, ; entirely by asbestos bsewing. . X Historical The dai light with r tosi knbwi Murray in years and v room, the o He died in ( revealed ext found to cor phthisis, Di asbestosis cc Cooke (192^ seemed to e pulmonaty fi Merewether have been m; and others, 1 Thirty Case Between : Out-patient I and twelve asbestosis. S( asbestosis wi in more than cupations in u^V?*. ^ 1 1 it"- roniE^GG i533r in 1 i 'J - *:? *[ bTo007328Jj to-- THE PNEUMOCONIOSES 877 &T- : the fibres are laid parallel. From the end of this machine the material pi received as a sliver or rope. Stripping the carding machines (fig. 389) fand cleaning the cylinders with a wire brush is a very dusty occupation. Si;-'*' Spinning and Weaving Spinning, doubling and weaving follow the process of carding. Dry aving is usually practised, for wet weaving has the disadvantage of certain fittings on the machinery. For non-textiles, such as millrboards, a wet process is employed. Fibred asbestos is mixed with clay, sent and water, and run through a series of sedimentation tanks to ^secure the finest of the pulp. This passes along the machine as an emulsion, ring drier and more doughy on its way, until it is eventually rolled it upon a cylinder. From this it is cut, removed and dried in the dryingjjoom. Subsequent operations, such as sawing, grinding, turning and alishing, give rise to much dust. Insulating mattresses are made almost atirely by hand from lengths of asbestos cloth, and are filled with fibred ^asbestos by hand, scoop or shovel, levelled by beating and finished by viewing. _ ______ ... i- ?Historical Summary **r.. LJ~ 1 o The dangers of asbestos remained for long unsuspected. They came to r light with 3. somewhat disconcerting suddenness. The first case of asbes- 3 Ptosis known in Great Britain was observed in 1900 and described by : Murray in 1907. The man had worked on a carding machine for fourteen C-i , years and was the last survivor of ten men who had worked in the card f >" f room, the others all having died about the age of thirty with lung disease, i He died in Charing Cross Hospital at the age of thirty-four, and necropsy '^revealed extensive diffuse pulmonary fibrosis. Although the lungs were- found to contain asbestosis bodies, a diagnosis was made of typical fibroid 1 phthisis. Difficulties of certification delayed further action and cases of " } asbestosis continued to occur. Real attention was drawn to the disease by 'Cooke (1924). But it was the case published by Seiler in 1928 which to. -seemed to establish an unequivocal relationship between asbestos and 5- pulmonary fibrosis which precipitated the inquiry leading to the Report of -Merewether and Price (1930). Reports of a heavy incidence of asbestosis `have been made in some German factories, especially in Dresden (Kruger -and others, 1931) and Berlin (Gerbis and Ucko, 1932). >* ) Thirty Cases in One Factory Between 1930 and 1934 thirty-seven workers in asbestos attended the -Out-patient Department of the London Hospital; twenty-five were women___ nd twelve were men. Of these, thirty were judged to be suffering from -asbestosis. Seven of these died; and in four necropsy showed that the asbestosis was complicated by pulmonary tuberculosis. Many had worked in more than one department of the same factory, but the principal oc cupations in order of frequency were as follows: spinner, weaver, riis- ; M tH f i :i ; |>4 u \\ GG 15338 | BB 0007329 | to at. * -- *, * '* . ft 5" :: ,4^ 1 878 THE DISEASES OF OCCUPATIONS `s,--^1"-1'tiAjjjff / >/' integrator, mixer, mattress maker, card cleaner, storekeeper, slab maker".jgjg| presser and machinist. The avenge length of exposure before theonsecofUi symptoms was seven years. Of the patients who died, one was a weaver" who had been exposed for eighteen months and another a storekeeperwho had been at work for nineteen yean. In many cases there was a4ong- v;J interval between removal from exposure and the onset of symptoms t longest such interval was eight years. 3 o :TM` va.. f Tt '* *' / ^ ttv - Symptoms The presenting symptom was dyspnoea. This was early, conspicuous^ and always out of proportion to the signs found in the chest. It was nearly always associated with non-productive cough, as many as eighteen cases.- having little or no sputum. Haemoptysis never occurred in the absence of pulmonary tuberculosis: it was found in three cases. In sixteen cases pain occurred between the shoulders, under the scapula or behind the sternum;. -it was never more than slight. In two cases a diagnosis of acute pleurisy had been made during the period of employment in asbestos, but in no case had. a pleural effusion occurred. A history of warn was obtained in thirteen, cases, of laryngitis in three and of conjunctivitis in two. vr fT r Physical Signs The patients were usually well nourished. Clubbing of the fingers was^^^^f present in six cases. Cyanosis was occasionally noticed, but was only slight. Examination of the chest showed limitation of the. respiratory excursion on -- **?-* both sides. The percussion note was never seriously impaired, but slight. -i:\jfC\- dullness was sometimes found at the bases. The breath sounds wcre> - : vesicular, and auscultation sometimes revealed scattered, medium, crepi- tant riles, often with a metallic tone, and situated especially at the bases--ygM. Added sounds were absent on repeated examination in ten cases. For .-^Sg^ obvious reasons the condition is not unilateral, and therefore displaccmmtrr-^-^Bgr" of the heart and other mediastinal structures was not found. >-- *%$}} Asbestosis Bodies in the Sputum Thirteen cases showed asbestosis bodies in the sputum. These-aie-'f golden-yellow structures of elongated bead-like form, often with bulbous ends (Cooke and Hill, 1927). The appearance of fully formed bodies has*; been compared to beads on a necklace. The beads vary in size and make up an irregularly segmented body. These bodies havi been found to vary ; ] length from 20 to over zoo microns. An asbestos fibre forms the ccntral.-^^g;. t core in each body (Gloyne, 1939). They are best seen with an oil immersion lens, and show up clearly without staining as golden-yellow structures (fig.. 390). They can be stained by hematoxylin. The tubercle bacillus was found in the sputum of five of the above thirty cases, and four of these dietL. c Ft in asbe fine ax opadti obviou thicket the fin limits apices in defi asbesti seen ir Radiographic Appearances The fibrosis in asbestosis is much more diffuse than that due to silica* ' In silicosis it occurs in the form of numerous more or less isolated foci, but : - --SgiPS^. ' GG I533<SH; i.f0733o'7; FiC. 390.--Asfcwtoi* Bodies in the Sputum magnified x.ooo diameters nn asbestosis as a fine network throughout the lungs. In radiographs it is so _ e as to resemble ground glass or fine cobweb (plate XVI). Homogeneous opacities of this nature are seen at both bases, and may later become more obvious as a fine punctate stippling. The inter-lobar pleura is usually .thickened, and there is a shaggy outline to the heart shadow. Ultimately the fine punctate mottling can be observed to have spread beyond the limits of the lower zone to the middle and even the upper zone, but the apices usually-remain free. This fine, diffuse, punctate mottling stands out {in definite contrast to the nodulation seen in silicosis. In fact, in advanced -asbestosis the degree of shadowing present would have little significance if seen in silicosis (Timmermans, 1931). *y. ^Prognosis Broadly sneaking, the length of time which may elapse between ex posure to the"dust and a fatal termination is only one-half of that in sili cosis. In other words, in asbestosis the fibrosis develops more rapidly. With continued exposure to high concentrations of dust, the fibrosis may be GG 15340 JS2S-"'-- i _e.k-4A?kt.!*s*r..."h;-- -. . tsSr :-" - ;&?** &-V. v . tew-- ? a*. p:!|:ii %^*p5^&v*-i4, J M SStfC.v:* 3 it-r1t'1i`- * sr-; P3SK* (MkV . nafcVtiW?."*`^.Tf. - ' ' 'Mk>T*r-vt^e\v>i - :--/ .Sr-r .- * *" wr -i. * i>*' ' ' ' :: 88o THE DISEASES. OF OCCUPATIONS ' fully developed in seven years, and may cause death after about twdvi-f|f&? yean' exposure as compared with thirty-five yean for ail cases of siiimsixs^^ "* The shortest length of exposure to asbestos dust which, has ulti caused death is eighteen months. It must be remembered that the existeice^ipTM^ l of a clinically recognizable degree of asbestos fibrosis in any individual,SsSSsjsi-fr an additional advene factor in the prognosis of any acute infection of the^JSIklungs such as pneumonia or bronchopneumonia. Pathology of AsbestosU At necropsy pleural adhesions are extensive and dense; often thick subpleural plaques of fibrous tissue. Large areas of the lung ire^ tough owing to the presence of fibrous tissue; emphysema is extensive but^Jfr^ usually localized to the lower and apical parts of the lungs. There aretwor^^E views regarding the mode of development of asbestosis. According ~mrh*^r^e2f one, the action of the dust is 'chemical; the other view supposes that 1 asbestos fibres act mechanically. Experiments carried out at the Saianamr^wi laboratories do not supportthe chemical theory, since aluminium hydroxide^^-^-' _ - which neutralizes the toxic action of quartz does not prevent nhditniTi'vS^Sr'T 7.' Moreover, asbestos fibres shorter than zo microns were found to bcs-ssSU relatively innocuous, whereas if the action were chemical an increase" potency would have been expected with reduction in particle size below, 5^^*;-, j microns, as in the case of silica. A comparison of the effect of asbestos | fibres. 15 microns long with those 2-5 microns long (King and others^r^*- f- 1946) showed that rabbits receiving the long fibres developed a nodula?,!^^ | reticulin formation comparable with experimental silicotic nodules; animalsv^S^ ! receiving the short fibres developed a diffuse interstitial reticulin forma-^^.'-f . tion* . ' ' * Effect of the Size of the Fibre --- . ------ The localization of the asbestos lesions appeared to depend on the sizei^^rL of the fibres; with long fibres, too big for removal by phagocytes,- reaction resulted in the formation of connective tissue within the with shorter fibres capable of being taken into the alveolar walls, there ____ diffuse interstitial fibrosis. These workers suggest that if the fibres wem-?^v;./;. shorter than 2*5 microns they would be completely removed from j alveolar walls and fail to produce fibrosis. Johnstone (1948) concluded frotiia^;te chnical investigation that workers exposed to high concentrations of tremelv fine asbestos dust did not suffer from asbestosis. The Saian*C-:;>^~' l workers conclude that asbestosis is caused by mechanical irritation .,. the asbestos fibres during the movements of respiration, and that thiaw^* 5 peculiarity is related to the flexibility of the fibres not possessed by other_ foreign bodies. The view that movement of the lungs is a factor is- sop' y^r" ! ported by the absence of reaction to asbestos in organs other than. the-'^J^' ^ lung. Wyers (1949) points out that if the fibrous character is absent, in the case of serpentine, the chemical equivalent of asbestos, the dust Ur^-' * ? inert. C a Ir' 1 y&'itXs#:-; GG JJH 1^^0007332 ,, Man welvc o. .icosis. ;as ultimatriv : existence individual is Section of the. ., nd_there,ar*r ,, the lung arextensive but__ tene are two -'ding to the ~ ses that thc_ he Saranac* i hydroxide asbestosis. und to be increase-iiJze hejQK-S^, )f asbestos id others, " a nodular s; animals., in forma* ii the size ' * ytes, the 1 - alveoli- - ~~ here was . . res were I ' Vom the cd from------ - Saranac n from iat this v other v *is"Eup---.an the 'Cnv asi-' dust is THE PNEUMOCONIOSES 88 r Incidence of Associated Pulmonary Tuberculosis f-- Precise information as to the incidence of pulmonary tuberculosis' ongst asbestos workers cannot be obtained, but the Factory Department igures for 1935 suggest a less dose association between asbestosis and tuberculosis than is the case with silicosis and tuberculosis. Thus among jot deaths from silicosis the disease was accompanied by tuberculosis in 6 per cent, whereas among eighty-two deaths from asbestosis only 36 per Jcent showed associated tuberculosis. - ^Association, with Carcinoma-of thc Lung j-In an analysis of 235 cases of asbestosis by the Factory Department ^1947), cancer of the lung or pleura was found to occur in thirty-one (13*2 cent, average age 52-1 years). These figures were contrasted with the such-lower incidence of cancer of the lung in 6,884 cases of silicosis, of Swhom i'32 per cent had carcinoma (average age 59*4 years). Usually the 'carcinoma appears many years after exposure to asbestos has ceased (see case 38, p. 882). o retentive Treatment Sag^tT-lH"asbestos mining wet rock drilling is imperative. In Great Britain ^legislation has been effective in controlling the disease. In factories and ^j%ptcxtilc mills the principle of locally applied exhaust ventilation must be j^pfeafdrced to prevent the escape of asbestos dust into the air of any room iaw?in which work is done. Hand cleaning of the cylinders of carding machines ^fgtt prohflaited while any other person is present, nor may it be done by hand 'T^gr.strickles or other hand tools. Those cleaning cylinders, filling insulating '^mattresses and entering chambers containing loose asbestos should be. Jggprovided with an efficient apparatus J>y means of which they can breathe ?3j'air free from dust. Suppression of dust in the cleaning of carding machines ^SsTjest ensured by the use of a revolving brush fitted with a cover and connected to a portable vacuum cleaner (fig. 391). Bv the use of closed-in machines, handling should be reduced to a minimum. In one factory, ^spinning frames have been totally enclosed in perspex with an ingenious ^device which permits easy access to bobbins (Wyers, 1949). Education of the worker must aim at a high standard of good housekeeping. UJ Pose 37. Asbestos spinner--exposure to asbestos dustforfiveyears~asbestOsis. A. R., a woman, aged 37, had worked from 1924 to 1929 in the spinning department of an asbestos works where the protection from ! dust was poor. In 1928 she suffered from a dry cough, and in 1936 5?\ 'from shortness of breath and occasional pain in the right side-oFthe chest on breathing. * On examination: five warts on fingers, the largest 3 by 1 mm. No ^-clubbing of fingers. Dyspnoea, but no cyanosis. Apex beat not dis placed, and heart sounds normal. There was diminished movement of the base of the right lung, with slight dullness, diminished breath D.O.--rrp ; 1 ; : \, GG 15342 i-fiL 0007333 | -N3af?s* - 'w.^f'*5 . -;. ^m^t- ,,..._^VLV. -- ''S7 ~ v >; -'-'JiSziini**' * : -TM44g3iS* * t :-:- I J~ ^ ^vcvv.4^'r''*;; -V; iV $ t*~-. ' ,,r,?. ?ti_S a; -*- - . i, ::ii j '/."'."Jr,-.*`L7-. 88z THE DISEASES OF OCCUPATIONS ] --:-; r.\r i (fa* __ :_'*35r~ ;V4.'TM4wi `^fiiisssr ,,:.' <*.* Fro. 391.--Portable Vacuum Apparatus for cleaning Asbestos Carding Machine. Note the Revolving Brush fined with a Coverand connected to a Vacuum Cleaner (Report on C`*tnferwrxa ronetnmt /or Supprnii*? Dmit m Aibntot Ttxttlo fMrw, /9J/) sounds and extensive creaking pleuritic sounds. A few crepitatianxar.'^ih,- both bases. No sputum. X-ray showed the heart to be normally situated, and there were fine homogeneous opacities resembling:^.: ground glass at the bases of both lungs. In 1935 the shortness of'^I breath was worse; there was a dry cough. On examination there were ->~ no warts on the fingers, and the physical signs in the chest were- un *fy*~ changed.' - -V yi' Case 38. Asbestos carder and weaver--exposure to asbestos dustfor threeytart--^^ --latent interned of twenty-five years--death from compression parapUgia^0'- secondary carcinoma of spine; primary carcinoma of lung; asbestosis.. ;,^v~r- M. C., a married woman, aged 43, L.H. Reg. No. 41149/1947.'^^^; ip/p-22: between the ages of fifteen and eighteen she worked aso^ carder and weaver in an asbestos factory. It is not known whether she; t cleaned the carding machines with a steel handbrush, but this method 'v' was in use at the time. She gave up the work owing to shortness of^sJ. breath. ' 25 years: she had frequent brief attacks of breathlessness some-- times with cough but was not disabled. "-'^SplSei?.. 16 years: at the age of twenty-seven she married, and later hadone ^- - ' miscarriage but no further pregnan1CcV^-SJ3he remained active, doing ah ^r.' . Mthe duties of a housewife.-^ ^1 : nuts -tysi**ms>L. *.**>* GG I5343;fll 'VU-: r *v.i` 'La I BB 0007334 THE PNEUMOCONIOSES 883 Four months: sudden onset of aching pain in the back of the neck ^-without any apparent precipitating factor. The pain radiated to both shoulders and to both sides of the chest, was continuous and severe ^enough to interfere with sleep. It remained for some time practically _unchanged, but had gradually increased in severity during six weeks., gjr'ir Three toeekt: she felt unsteady on getting out of bed in the morning ** and since then ihe had become progressively weaker and more un- -.JT. steady on her legs. There were occasional involuntary movements of the legs, usually flexion of the knees with plantar flexion of the ankles. ^.-Occasional parasthesic of the legs. Hesitancy of micturition. Bowels ' \open regularly. .. .. - On examination: temperature 99* F. Pulse its. Respiration 22. A nervous distressed woman, in considerable pain. Furred moist tongue. "No pallor. No enlarged lymph glands or (Edema. Regular pulse. Apex ig&beat 1 inch lateral to mid-clavicular line. Blood-pressure 120/90. Heart sounds normal. There was some impairment of resonance and li diminution of breath sounds with coarse crepitations at tire bases of -both lungs. The abdomen, including digital examination of rectum and vagina, showed nothing abnormal. Nervous system: an anxious essrbut co-operative lady. Cranial nerves normal. Upper limbs normal. Lower limbs--approximately symmetrical spastic paralysis with brisk reflexes, ankle clonus and extensor plantar responses. Abdominal re flexes absent, and some weakness of lower trunk musculature. Loss of sensation to pin-prick, postural sense and vibration up to the level of D6. ', ^_ Investigations: catheter urine: trace of albumin; deposit; calcium * oxalate crystals; culture sterile. Blood count: hemoglobin 89 per cent, , red blood cells 4,730,000 per cm, colour index 0-94, platelets 3; 255,000 per cjnm., white blood cells and differential count normal. ^Cerebrospinal fluid: clear, colourless fluid, under-normal pressure, ri-rising unevenly on jugular compression to 300 mm., and falling " similarly; no increase in cells, protein 500 mgm, per cent, Lange Sr lit,art, Wassermann reaction negative. X-ray ofchest: lung markings y- heavy throughout, excessive fine interlacing shadows at bases, no fTnodulation. X-ray of spine--the body of D4 is smaller than its y neighbours, especially in vertical height, and is mottled. The pedicles 7-. are not visible. - Progress: while in hospital the pain continued without much Iteration. In the middle of the second week she suddenly developed hk severe pain in the left chest, became dyspncsic, collapsed, pale and cyanosed. Some relief was obtained from morphine and oxygen. This ''was followed by fever up to ior-8 F., with rapid respiration rate and two further attacks of chest pain. Electrocardiogram at this time showed absent Q and inverted T in lead 3 with right axis deviation, -the' rate being 1S0. She became steadily weaker and died 2k weeks- if.after admission. -- ------ -- 1 ,.I I- i ; GG 15344 JMiB 0007335 7i S84 THE DISEASES OF OCCUPATIONS Necropsy: Professor Dorothy Russell made the necropsy(L.H. 2S2/1947), of which the following is a summary, ~ v. . . ' , ' --# Secondary carcinoma of thoracic vertebrte invading epidural space:: Primary carcinoma of lung. Asbestosu. : rocks. Ta andManc the PjTen Uses Dark grcyish-black reticular fibrosis throughout both lungs, Talc is penally lower lobes and right middle lobe, with conspicuous su! . is the-mai; pleural fibrosis (0*5 cm* deep). Area (3X3X3 cm.) of palf grey-^py- --ft i^ soft: carcinoma beneath pleura of mesial aspect of left upper lobe. Clear substance. yellow pleural effusion, left (3 oz.). A few fibrous pleural adheaioi r7..by tailors f over posterior surface of left lung and mesial aspect of-right'uppers - marketed i lobe. Secondary carcinoma of hilar glands, most marked right, and . . ,, is used in t one in superior mediastinum. Secondary carcinoma of greater pare of for the mar bodies of 2nd to 4th thoracic vertebra. Collar of growth encircling - -Nearly 25; dura over 4th and 5th thoracic segments. Patchy softening of spinal ; which the cord at this level. Nodule (1 cm. diam.) of secondary carcinoma in widely use mesial surface of left parietal cortex. Secondary carcinoma in supra- packing pa clavicular glands.'Swollen red pulp in spleen. A well-nourished, edentulous woman. Microscopic. Lungs: conspicuous anastomosing bands of dense.fibrosis containing numerous asbestosis bodies, often in dumps, and. -i^ associated with foreign body giant-cells. Similar zone beneath pleura- :-V^ of lower lobes; less marked and interrupted over middle lobe. Coa-.-.^i^r, gestion and emphysema of residual lung tissue-; many macrophages and occasional asbestosis bodies in alveolar spaces. Left upper Idx; --v-i' similar changes, together with ill-defined, infiltrating tubular, - -f: columnar-celled and polygonal trabecular carcinoma beneath mesial ff? Pneumocc -------- In New of the work fine; straigh increased st radiological <n a talc mill there was le . . appearances pleura, apparently arising from bronchus. Gland from right hilum:. A Case pro focus of secondary polygonal-celled carcinoma; anthracosis and a few ,^i*j collections of asbestosis bodies. Right and left supraclavicular glands: extensive secondary carcinoma. Fifth thoracic segment scith dura? ex- . The first was publish* years of age, tensive secondary carcinoma of epidural-tissues, not penetrating dura.. ---^-; Permeation of many veins. Engorgement of pial veins. Ill-defined' .fourteen yea was that of t wedges of ischsemic softening in both lateral columns of spinal cord, v extending into crossed pyramidal tracts, and a few smaller similar fod. in anterior and posterior columns. Thoracic vertebrte ?-j trith intervertebrai disc: extensive osteoclastic and osteoplastic secondary card- which was p artic incom 0vr both lu noma of spongiosa and periosteum. Considerable necrosis of medullary tissue. Left parietal cerebrum: nodule of secondary carcinoma in r-.y nodules whii `Microscopic superficial cortex. Spleen: slight myeloid reaction in pulp. appearance t to 9 mic (b) Talc Talc is a hydrated magnesium silicate, 3MgO.4SiOj.HjO. The purest deposits occurs in association with dolomite and magnesian limestone, where the talc owes its origin to the hydration of the magnesium silicate nuuoai* which were formed during the earlier metamorphism of the carbonate- particles app Uere similar Pneumoconi 5* ^used o, horogenic tf "nres in asb< & THU f ; t' `\'