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The a American / Ceramic Society , February 15,1993 1 hereby certify that the attached copies of Ceramic Abstracts, Volume 19,1940, are true and accurate copies, which are maintained in the normal course of business at the American Ceramic Society, 735 Ceramic Place, Westerville, Ohio 43081. I cannot verify the accuracy of copies from Iron & Coal Trades Review, Volume 139,1932. Christine Schnitzer Product Manager Ceramic Information Center 735 Ceramic Place Westerville; Ohio 43081-8720 614 890 4700 TWX: 7101109409 SC-ALL-01981 SCF-ALL-00635 SC-CER-3956  18 (4) (!) CERAMIC ABSTRACTS ' Compiled by The American Ceramic Society Volume 19,1940 Ross C Pmtnr. Editor Mary J. Gat ) Emtlt C VAX Scrokcx > Assistant* Dorothy J. Walucs J CornmitUt on Publications: J. D. Scluvah, Chairman. E, B. MAMAXXt, J. B. Avstcj, A. N. Fi.vx, R. C Pvrpy N t* r- K r. h k V ABSTRACTERS /. &. Aunla L-M. Chord* A. A. Arwi W. U. Coha l R. Bunn M, V. Coodqtd fcW.lV. Bartlett P. 5. Dear A. C. Itvta FmoY Fbber O, A. Biddle y. 0. Po*tr A. Oiddulpb . L. Callup t\..II-I.BBoruacukni er D. Oat * P. I* Budnikov Rohm Malle J. C. Cbanett Alas HerrcQlieiRi R. A. Heiodl P. 0. Herold m. l. mi C. M. Kg 1. I. Hyde Herbert tSU B. B. BCtekultta twar C. R- SbtHoo K. Eo Slapeod ems* w, toeweoifcal F. S Mellette Aliiii Plant BL V. Poor A. P. So* F. E. BoaaeaeaheU. Katherine Reed K, fc Richardeoo R. A. Rctbrk A, O. Stem B. H. Strom M. Take* V, 5 dt MvU 1*. F. Map AB.. CB.. dReuatrwieechi B. H. McQeUaod j. P. tfhaook U. E. Tblew Hao# Tfcuraaucr K. J. Vi J. Mo K* UfilQe Sluttatk F. J. Z\vamit Editorinl Oficc: 2525 North Hlfh Street, Columbus, Ohio * Publication Office: 2Uvh and Northampton Sirteu, Easton, Pa. *. K -v* v* V i & 1940 General 79 General Ceramic laboratories: Georgia School ol Technology. Anon. Ceram. Ate. 34 IX) 12 (1939). Massachusetts In stitute of Technology. Ibid.. |2| 44. New York State College of Certnicf- Ibid,, p, 43. Rutger* Uaivtrtitr. Hid^ (31 78. University of Illinois* Ibid.. |1| 13.--'The laboratories art briefly described and illustrated. F.G.H. Ceramic schools. Current survey of ftatua and prof- reta. Anon. Ceram. Arc. 33 (6| 171-91 (1939).--A comprehensive survey of ceramic schools tbroufhout the country is riven. The course of instruction, the teaching staff, the research staff, and the student body of each of the following schools are described: Georgia School of Technology, University of IUinoil. Massachusetts Insti tute of Technology, Missouri School of Mines, New York State College of Ceramics, North Carolina State College. University of North Dakota, Ohio State University, Pennsylvania State College, Rutgers University, Virginia Polytechnic Institute. University of Washington. Univer sity of Oklahoma, West Virginia University, and Carnegie Institute of Technology. Illustrated. F.G.H* Contract law for engineers. L. T. Faxes*. Cbm6usturn, 11 (2J 33-34 (1939).--F, explains implied sad ex pressed contracts, as interpreted by the higher courts, with particular reference to the employment of engineers and personal services rendered by them. The liability of employers in such cases Is illustrated by a number of court decisions, some of which are cited. H.E.S. Control of speed, la important factor In cement manu facture. Axon. Concrete, Cement MtU Ed,. 47, 233-39 (1939).--Early devices were friction driven. Inter, vari able-speed motors were used. Now a vari-pitch speed changer is used which is operated by a small pilot motor and which is either automatically or remotely controlled. New power self-synchronising drives may be used to keep a kiln and the kiln feeder in synchronism. \VJ).F. Development of central-heating systems- Lruoz Raxzl Ceeundk.*Int.. 60 (30) 753 (1937).--R. describes the de velopment of modem central-heating systems. A new type of installation is explained, and various examples are calculated. * W.DJw * Effect of condensate extraction on efficiency of the beat cycle, W. M. Mnjm. Combustion. 11 (2| 30-32 (1939).-- M. contends that the value of high superheat as a means of improving the efficiency of steam power plants is being overestimated and recommends the use of high initial steam pressures at moderate initial superheat combined with the mechanical extraction of condensate at appropriate stages of the expansion. ' H.E.S. y Fatalities from silicosis and asbestosU; their Incidence In industry. Anon. Iron or Coal Trades 139 [37321 336 (1939).--The annual report of the Chief Inspector of Factories shows that from 1935 to 1933 Inclusive, deaths from the two lung diseases In the refractories industries and in the manufacture of pottery have been approximately Constant. Le.. G3 in 1935, 56 in 1936, 83 in 1937, and 60 in 193S. Sandstone quarrying and dressing took 40 lives in 1935.43 in 1936.19 in 1937, and 27 in 1938. Preventive measures have aided In s generally small decrease: some of these measures axe as follows: (\) use of alumina (or flint in china bedding. (2) use of alumina for siliceous ma terial in parting powders. (3) use of noosiUceous abrasives for sand or flint in blasting, (4) use of nonstticeous material for kiesctgubr in the slow cooling of steel, and (5) use of nonsUiceous material for silica brick for lining steel and Other furnaces. See '`China--," Ceram. Abs,, IB (21 54 (1939). . M.H. Gss heating installation. N. Dirrxiat. Gtsundh,!*{,. 60 (45) Q* * (1937).--D. surveys the developments of gas beating after the World War and discusses the gas single* heating system, the ga* ccntral*bcatng system, special gas unks. tanks with built-in burners, rentability and gas prices, and the experimental capacity of a boiler on a low pressure steam-beating system and oo a warm water heat ing system. Results of conducted experiments are stated. W.DJC. Handling tad disposing of recovered fly ash and dost, J. T, Drcrsca. Cbmhwslian, U (5122-24 (1939).--Thru* methods are reviewed, including the vacuum, the snap, and the introduction of the dust by means of n water- cooled ram into a slaggiag-bottom furnace near the level of the molten stag. The last method is discussed hi detail. ff,F3, Health damage by means of industrial dust. Otto ScaciTt. Garmash*. 11, 57-66 (10391.--Pure coal dun is not dangerous; neither is silicon carbide nor corundum dust. Tin, copper, bronze, and aluminum dust make alight alterations in the lungs, and iron oxide makes stronger alterations, but none of these dusts affects the health. Of the dangerous dusts, free silica usually causes sflicosii, which Is the most widespread and dangerous disease, after only a 5- to 10-fear exposure. Asbestos dust causes asbestosis by mechanical irritation. Lung cancer b caused by radioactive dust. The symptoms are like those of sili cosis. Chromate dust or mist causes nasal sores and also cancer. It has a long latent period, up to 24 years. Thomas slag cause* a severe lung inflammation, as It reduces the resistance of the body to bacteria. This can occur im mediately after exposure and has a high fatality. Fyto- luiite causes a different lung Inflammation. Glass wool acts in a similar tnaoner to asbestos. Over sensitiveness to flour, grain, hair, etc., causes asthma. Certain fungi can grow in the lungs. Methods of prevention are dis cussed generally. TJ)J, Hetithy elr, a guide for plant superintendents and workmen. Otto Hunt*. G*sundk.-Inj,. 60 (441 676 (1937).--A review issued by the German Society for Labor Protection give* the various kinds of air contamination and testing. Natural and artiffeial air-conditioning methods are discussed from the viewpoint of health, and a special chapter describes the airing of workihops^oflkes. How benzol poisoning may be avoided. Anon. Gesundk.* Ing., 60 (321795 (1937).--Forming benzol vapors must im mediately be caught by suction. A good supply of fresh air is necessary duriog the cold season, and the air should be replenished with prewarmed air. Benzol vapors are heavier than air and, for this reason, sink to the floor. When installing a new air-ventilating system; therefore, suction openings should be located in the floor or near it. Pieces treated with s benzol-containing solution should be dried in a well ventilating drier cupboard or special drying room* Beuzol-coatainiug vessels must be kept covered. WDX Improved system In the application of noncondensing or extraction turbines. H. W. Caoss and . S. Wgun, Ja. Combustion. II (l ] 32-35 (1939).--Since electrical output is definitely established by the energy drop between initial and exhaust conditions and by the quantity of steam flow, increasing the total steam pressure at the throttle far * given pressure increases the available energy and conse quently the electrical output.- The application of'a com bined desuperheater and feed-water heater at the ex haust is advantageous in realizing gaum Irons the Use of higher temperature steam. Examples demonstrating the possibilities inherent in such systems are illustrated and explained. H.E.S. Lighting for special Industrial purposes. W. R. Stevsns. Trans, lUum. Eng. Soc, [London], 3 [1] 3-16 (1936).--$. describes installations requiring special lamp fittings for explosive and moisture.riddtn atmospheres and the use of special sources of tight, such as carbon dioxide discharge, daylight tubes, special daylight tungsten fila ments, end high-voltage fluorescent tubes, for color match ing surfaces and special inspections. HJC.R. Living sd working conditions In the tristate mining district. Evan Just. Jtfiiriirg Cony. Jour,. 25 [11] 44--*5 (1939),--Dust in the mines is kept within safe limits by wetting down, spraying, and ventilation. Above ground, dust from "chat piles'* is practically nonexistent ss they'* are coarse material. On windy days dust is blown from a few fiat accumulations of sand. Road dust, however, ac- I X. I I I {WO ' . * Central . SI i icstl water btrdimi has been developed by the Gentian and the die and shape of the body. There is an optimum I Soctety for Chemical Apparatus. W-D.XL temperature at which drying is most readily carried out; I Surface heat loutf from outside foresee vaZU J. G. the smooth nature of the relationships between greatest ] Coutant. Heat Trtalint ct Forgtnf. 25 19) 463 (1939).-- safe rate of drying and the dimensions of the test pieces I Aluminum paint reduces heat loss from furnace walls. suggests that ea ultimate undemanding of the phenome See Ceram. Abt*. 19 UI 16 0*40). $. non of cracking will be achieved. - A theory of the mechanism of the flow of water through ; BOOKS AND SSFAlUT* FU8LXCATTOMi plastic dap during drying has been developed, in which the * A.S.T.M. Standards, 1939. . Amixicah Soosty fob force causing the flow Is regarded as a repulsion between Tsstiwo Mateuau. Philadelphia, Pa. Price to non the day panicles which are separated in ell directions hr members 35.00 one part, 31100 two parts; 123.00 three water films. A measure of this repulsion is obtained from part*.--The took is fa three parts; Metals; Ptrroum mad the moisture contents assumed by the day when various noofemus metals are discussed; methods of chemical pressures are applied through porous pistons, into which analysis are not given. General testing methods are pre the water is allowed to escape. This pressure Is an ex sented. n, KonmetalUc material*--constructional. This ponential function of the moisture content as is also the part includes cementitious materials, concrete and aggra- `'aqueous conductivity** or the me of flow of water through gates, masonry building units, ceramics, refractories, pyro unit volume of the clay under unit pressure. On this bads and tile, thermal insulating materials, timber preserva the distribution of moisture content at any time through tives. paints, varnishes, and lacquers, road materials, out a drying shape can be thtofuicaUy calculated, the waterproofing sad roofing materials, and soils. General analysis being analogous to that of heat diffusion* A . testingmethods and thermometers arc described. 1H, Non* strict solution Is not possible, but experiments on a num * metallic materials--general. Fuels, petroleum products, ber ol days show a means of approximation which permits electrical insulating materials, rubber textiles, soaps and. the # calculation of moisture-content distribution in bars detergents, paper, plastics, and water are covered, Gen- drying from one end only. The experimental verification eral testing methods are given. Available from Amer. of the theoretical results confirms the hypothesis. Soe. Testing Materials. 260 5. Broad St, Philadelphia, pa, Many years* study of electrical insulation and the ma F.F, terials used therefor has greatly improved the reliability Finding List for United States Patent, Design, Trade end the advantageous selection, preparation, and use of Mark, Reissue, Label, Print, and Plant Patent Numbers. Insulating materials. Better insulators have been de- M. JUnball and E. B. Watson. University of Cali- vdoped, thus reducing the size and eventually the cost of fornia Press. Berkeley. 1938. 31pp. Price 33d* Reviewed electrical apparatus of alt kinds without toss of quality. in Mtck. mu dl [3J 402 (19391. F.G.H. The suitability of certain glasses for use in the manufac Report of the Department of Scientific and Industrial ture of telephone Insulators is shown. The degree of I Research, 1937-193S. H. M. Stationery Office, Loudon. homogeneity in optical glass U almost completely de Price3s. Reviewed in Pottery & (fats Record* 21 (4J 89-90 termined by the temperature conditions prevailing during (19391.--Methods have been developed for assessing the annealing process. An investigation has beta made of * weathering characteristics of day products fired under the maximum temperature gradients la an annealing oven various conditions. Work on clay roofing tile has been consonant with the production of substantially homogene continued. Investigations on refractory materials Include ous optical glass. The cooling schedules of the annealing (1) the pressing process and it*' relation to the texture of process were experimented with to decerznuic the nlakiMn . clay, silica, and sHUmanhe brick; (2) the drying of period of annealing for glass of high optical quality. daywsre; and (31 the firing operation. A careful study of Methods of producing light etch marks on glass have the smoke emission from various intermittent kilns firing been developed, and an optical system to enable the degree blue and brindled heavy day products has been made; of polish of a glass surface to be assessed has been devised. and suggestions are advanced for its reduction and con The preparation of filing materials for etched lines, required trol. Laboratory work aiming at relating the conditions to he unaffected under specified conditions, is described. of atmosphere and temperature with the color of blue A.B.S. firing days has also been undertaken and has progressed Silicosis and Asbestosls. Edited by A. J. Lanza, satisfactorily. Oxford Vaivtrtity Frets, Xew York, 1933* 439 pp. Drying cracks are due to differences in moisture con Price 14.23. Reviewed in Mech. nt.. 61 [3] 405 (1939).-- tent established in different parts of the day body, espe The medical and public-health aspects of these industrial cially between the surface and the interior. Differential dust diseases are comprehensively presented in this book, shrinkage thus occurs as drying proceeds, and stresses are to which several physicians have contributed. The history produced. The direct method of studying the problem of the diseases, their symptoms and diagnosis, their consists in determining the fastest rate at which particular pathology, and their prevalence in various occupations are * shapes of a given day can be dried with safety, and the discussed, as well -as methods of prevention and control. variation of that rate with such factors as the temperature Each section has a bibliography* F.G.H. y 4 t t **ti # ^11 . \ t. ' I` .Vo. 6 dlcro* Uyws t from (with i [gdi fcrmw . * Uses up of b is* ID. irgicsi R. C. W. B. 3433. ad lactro* uH. "ST res.-* taagmite ore it ore white S tall er ore* LH. )HAU. 9.--Is 'ate of itt to op to it hit h add. larger which above, lisxao* ume of not) U as hi* ug and v rates :hn is tegive 33. 1940 Chemistry and Physics--General 149 compostton and properties of the solid mad liauid phases, led the g*J phase. 3.3. & E.S. prevention and treatment of lead poisoning. Isis Eiu.li. Ormii Hetitap, S3, <139-41 <1939); Chem, Abu, jj, 3329 (1939).--la Hungarian Pb works. Pb poisoning occurs in 10(> to 200 of 1U,(M> laborers annually. Lead ac cumulated within the human organjUm can be mobitixed by modifying the Ca/P balance cautiously. This was done in eUnical experimeau by a diet poor in Cl and 3 to 10 pm. 2Ca phosphate given each second day for 3 to 4 weeks. Acy secondary effects of phosphate can be balanced by the administration of thiosulfate from time to time. Silicic add gels: EX. CfuauSi B. Hum ako Kaaits tl\ PaTo.v. JauU Pkrt. Cko*r.. 44, 57-42 (1940).--The effect of a change of pH on the time of set of gels produced by mixing solutions of sodium silicate end acetic add is discussed. For Pan V set Ceram. Abu, 13 (31 103 (1936). RAC< Theory of light scattering. S. Paxthasajutwy. PkiL Mat- 29 (193} 148-53 (194U).---P. shows that the scatter ing of light observed by fCmhnan in binary liquid mixtures ("Molecular. . .." Ceram. Abs., 17 (31 119(1933)) Is purely molecular, while no scattering arises from dusters, if any, ac the critical solution temperature. No new theories as, e.g.. those of Frenkel. Cans, or Muller, appear to be neces sary to explain KrajraatTs results. ' ' HH. soon Science Front, 1939. F. Ssgntrooo TavtOn. Cassell 5: Co, Ltd., London. Price 7s 6d* Reviewed in Ts'iffc* lit. Sapp.. 39 (19841 ^9 (IW0),-T. describes recent developments in sdeace. induding theoretical researches and technical inventions. Illustrated. K.W.W.B. tATXMTS Cadmium-red manufacture. Walts* F. Miistkx (Interehemical Corp.). Can. 387.430, March 12, 1940 (June 1$, 1937; in U* $. July 9, 1938). G-M.H. Enamels and glazes and method of producing. Ca*l OssaULvota and F. H. 2*chacxs (slow G.m.b.H.). V. S. 2.194.246. March 19. 1940 (May 20. 1938).--A preparation for improving enamels, glazes, etc., comprises a magnesium borosilfcate having substantially the follow ing composition: silicic add 30 to 50, boric add 10 to 30, m20a%gn. esium oxide 15 to 35, and alkali compounds 10 to Magnesium titanates and method of making. J. A. Flcxkxtt and uccxs TVaXNS* (Titanium Allay Mfg. Co.). L\ S. 2.10(1,325, April 9. 1940 (March.5, 1938). --A calcined synthetic magncsia-iitaaia composition con* taming chiefly finely divided magnesium titanatc chemi cally combined with 3 to 12% of silica and alumina, the ratio of silica to alumina ranging from 8:1 to 12:1. of panicle size substantially an wtthm the range of 0.5 to 2 microns, and having a refractive index of about 2.15. Production of beryllium compounds. Cajuo Aoamou fPerosa Carp.). l\ 5. 2,190.048, April 2.1940 (March 22. 1937;.--A process for the production at beryllium oxide from minerals containing beryllium and for the cydlc re* covery of the reacting agent employed consists in powder* Ing thfi beryllium-bearing ore. "mixing the powder with an alkali bifluoride in an amount corresponding to 2 molt, of bifluoridc for every BeO molecule present in the ore. add ing water to form a paste, compressing the paste to briquettes, heating the briquettes to a temperature be tween 550* aod 800*C. to cause the fluorine to combine with tbs beryllium to form a double alkali fluoride, leach ing the reaction product with pure water at a temperature of about 90* to lu0*C., adding alkali hydroxide to the alkali beryllium solution to precipitate beryllium as beryllium hydrate and form neutral alkali fluoride, sepa rating the neutral alkali fluoride, calcining the beryllium hydrate to beryllium oxide, and treating the neutral alkali fluoride with a nrons add other than hydrofluoric to con vert the neutral alkali fluoride to the corresponding add fluoride. Purs titanium dioxide. W. XV. Plzchnul ako A. TV, Hixson (Hational Lead Co.). Can. 386,985, Feb. 29.I94U (Oct. 12. 1937). G.M.H. Pure titanium oxide. TV. TV. Pttcxint* asm A. W. Hixson (National Lead Co.). Can. 386,625, Jan. 30, 1940 (March 7,1938). * CAiB. Titanium pigment manufacture* Roscxt TV. Axcxcv and Auti G. OrrECAAXD (National Lead Co.). Can. 380.623, Jan. 30. 1940 (Nov. 29, 1937). G.M.H. Zirconium oxide and method of oaldnc. C. J. Ksxcrx. and D, S. Haxx (Titanium Alloy Mfg. Co"). U. S. 2.194,* 426. March 19. 1940 (July 28, I93n,--A orytcslffne zir conium oxide obtained by the calcination of a zirconium- oxygen-carbon compound without substantial grinding of the calcined product characterized as an essentially white powder and as being essentially white in color and consist ing of crystal particles having their length greater than their width and their thickness less than their width, an index of refraction of about 2.3 to 2.4. and an adsorbed colorless carbon content of about a stoichiometric equiva lent of 1.64% carbon dioxide. tsed la teral is V.C values. m.9 44, floocu* stannic .ioxide. ydrox- A.G. tSONQ. 1939). $e rule 2.H. No. 7, .led on mid be -fleet of tstidty Oust of qi cm. hetero* rature. General Absorption of lead and arsenic through tldn* Amok. Jour, Amer. Med* Assn.. Queries or Jtimer tfoen, 114, 6H4 (Feb. 17.1940).--Lead ana arsenic absorption through the skin does not occur to an appreciable extent in contact with aqueous solutions of these compounds in concentrations be low 0.5 mgm. per 100 cc. of solution. It is unlikely that sig nificant quantities could be ingested because of conumi- asted hands. F.5.M. J Clinical studies In asbestos!*. M. J. SroMC. Amer. * Rer. Tubttc.. 41,12-21 (Jan.. 1940),--This report is based upon examination of ISO persons formerly employed in the opening, carding, spinning, and weaving departments of an asbestos brake lining plant. F-S.M, Compensation for industrial injuries and occupational disease*. E. R. Kooxti. Jeur, Amer. Med, Ashr., 114. 563-69 (Feb. 17, 1940).--K. gives an excellent discussion of a few of the many legal and medicolegal phases of com pensation taws of prime importance to physicians interested m the field of industrial medicine. Tables show the com pensability of occupational diseases, limitations of time and cost of medical and hospital benefits in compensable injuries and diseases, and the determination of medical matters under compensation laws: all data are given by states. F.S.M. Consider the audience. S. Maaton Tvcxt*. ASTM B*U.% No. 103. pp. 27-29 (March. 1940).--T, stresses the Importance of presenting paper* effectively. The -causes of complaints are considered. The preparation of a technical paper is taken up with regard to the content and Style. The manner of presentation is also considered. The audience must be considered Arte is technical paper presentation. F-F. Dust-control systems for the metsi-flnishlag Industry. Ricxaxd T. Pact. Metal Clroeing fir Ffaishritg, 10 [a\ 530--47 (1033).--Dust Is undesirable in any industry. Many of the metal-finishing processes, e.g.. sandblasting, grinding, buffing, polishing, etc., art outstanding dust producers. Control procedures discussed are (1) personal respiratory protection. (2) substitution of a less harmful material causing the dust, 13) wet methods, (4) complete enclosure of the dusty process, (5) segregation of pan of the equipment, (6) improved ventilation, (7) partial en closure under negative pressure, and (8) local exhaust ventilation. A detailed study of dust-collection systems is presented. Air motion is discussed, and a table of air speeds in ducts necessary to convey various materials is given. A table shows the minimum thickness of metal for straight exhaust piping. Fans and cleaning apparatus 1940 Genera! 205 investigations arc of considerable importance and fre quently accompany the chemical work. The department * equipped for complete mmcralogtcal examinations by t*a. I microscopic and other processes used in determining rocks* minerals, ores, and concentrates of an types. It is fre quently possible from the results obtained to offer opinions upon the commercial value of a mineral product or to five deice on methods of preparation for the market. Chemi cal and mechanical analyses can also be made of soils. K.3L Tittl subacute occupational lead poisoning. Wesker KCtfA*or. Arch. Coverbepath. o' Garcrbekyz., 0t 407-13 * 1939).--Industrial lead poisoainf as a rule is a chronic poisoning. Characteristic symptoms appearing suddenly* like the colic and intestinal stoppage, show that the poison has been at work in the system for a long time. Has I Acute poisoning as an industrial disease Is seldom en countered. E. reports an acute case which came to the. Berfin Clinic for Industrial Diseases and discusses its manifestations. On Dec. 4, 1938. a sprayer of lead. 49 years old. was brought to the clinic In a dangerously Ul condition. Very carefully and fuQy he was examined: the next day be died. Tor several weeks as an occasional worker he had been spraying cable muffles 1a a cable plant. The workspace was 3 x 4 x 3m.; the spraying was expected to be done under a hood. The worker used a spray pistol in which a lead wire was inserted and the propane gas flame mixed with air* which was introduced into the pistol at the same time, melted the lead wire. The molten lead was at once ejected by the pressure of the air. spraying the muffles revolving in front of it During this process the worker was expected to wear a mask and to manipulate the pistol through slits. About the middle of November he had been seized with violent pain and ronutiac; he was off from work for 8 days and resumed work again late in November. The hood apparatus was then out of repair; three other men working m his absence In the same small space, with very low suction In the ventilating apparatus, caused the returned worker to ask for the night shift where he could be alone. On November 30 he was overcome with the same violent symptoms as before. Being somewhat better by the next night, he insisted on working, only to return home in the same con dition. with additional symptoms; his wife noted that his fare was as black as lead. E. details the man's further breakdown and the efforts of the company physician in palliation; these failing, the victim was transferred on Dec. 4 to the Occupational Clinic. The plant conditions under which the lead spraying took place were examined and reported on by E. after the autopsy. A Urge bote was found in the left side of the framework supporting the hood through which the sprayed lead had been escap ing Into the small enclosure; lead dust lay heavy on the "gtasi valves of appliances ^carrying the cables; 'the docking and shoes worn by the various shifts were toaded and sodden with the scattering lead dust; the mask of the worker was In disrepair, so that be might not have worn it on bis final night shifts. He must have breathed the lead dun in Us most finely divided particles, i.e., In almost molecular form. Such an lerocoiloid condition is taken up by the organism with special ease and constitutes the highest possible risk to the subject. The lungs In this case were permeared with it. and the blood readily carried this fatal dust to the entire system. From the evidence derived from the illness, the autopsy, and the plant. E. concludei that the poisoning could be called acute but also wihactfic. the worker evidently having been sensitized by his first attack and the subsequent exposures, massive in character, sustained December 1 and 2. An inspector testified that, after being placed on the night shift, this worker had done the work of three ordinary men on the spraying- Hence his constitutional resistance was utterly broken down beyond repair. The lead content of the urine was 2140 v in 10 pm. of dry feces, 490 y in 10 gm. of the fiver, and 370 y in 10 gm. of the kidneys. K.R. Fuel gas generator. Harry A. Corns. Ralph B. Stitiks. a.no Wiunaa J. Dariiy. 1*4. c. Ckem., 33 (8f 731-62 (1940).--Developments in the use of electrical s&crgy as a source of beat for the carbonization of coal art - described. Illustrated. F.G.H. Glass Industry of Ohio. Aarwtnt S. Watts. .Okie Slate Cfate. ttf. Exp*. Sia. News. U (At UM3 (1939).-- Ohio b the thud largest glass-producing state and baa twenty glass plants. In 1797 there was a glass plant on the Ohio river; by 1835 they were all over the state. The production of hollow glassware has Increased twenty limes since glass blowing machinery has beta introduced. Ohio h an Important producer of flarglan. Today this la drawn from the tank as a continuous fiat sheet. Oihcr Important products are electric light bulbs, fiber glass, and glass blocks for use In building construction. W.D.F. Pleat laboratory. 3C. SrtNGLXR. Tonind.-Zit., 62 (44) 492-93 (1938).--The plant laboratory has the follow- lag tasks: the testing of raw maieriab and half-finished and finished products, the working out of new formulas, improvement of old shapes and construction of new shapes, and local research. . W.lL Prevention of industrial dermatitis. J, V. Klaqosx, E. R. Gross, a,v H. Brown. Arch, Dermatol 5* Sypk* Oof., 41* 331 (Feb., 1940).--Much of the Industrial skin disease b caused by the methods of cleaning the skin. Skin cleansing, methods and materiab used, and the use of protective applications arc studied. Formulas for eight protective applications are given. Substitutes for me chanic abrasive soap are listed. Various kinds of soaps and detergents, such as triethanolamine soap, naphthenic add soap* and sulfonated oils, are discussed. The detergent properties of the vegetable meals are not suffideatly^agyro- RrTophjIlite dust; Its effect and control. M. F. Tan. A met, hut. ifs'atnc Met. Engrs. Tech. Pub.. No. 1179; Mining Tech., 4 (3) 13 pp. (1940).--North Carolina is the only commercial source of pyrophylUte at present. Pyro* PhyOhe occurs associated with quartz, together with chloritdd and seridtt. All the pyropbyllht marketed is ground; It Is classified by air separation. It b mined by open-cut, glory-hole, and underground methods. At only one operation has work been carried on since 1920. Underground. the free silica content of the dust is 35%; 80% of the panicles are less than 3 microns in size; dust concentration rises to 500 million panicles per cu, ft. when drilling. X-ray examination was made of 101 workers; of those with over two years' exposure. 35% were affected; two died. The lesions were the same as those produced by free silica alone. The threshold dust concentration allowable underground u 10 million particles per cu. ft. Drilling b done wet; stopes are ventilated by "ventubes." Above ground, tight housing for machinery and exhaust ventilation have been hut ailed. These procedures give the-required results. W.D^y. Recent Commission findings. Ahon. Okie Industrial Commission Monitor, 11, 41--42 (March, 1940V--An employee of a steel foundry worked from May, 1922, to June. 1939. in the cleaning department in the foundry, where his duties required him to remove hardened sand from castings by use of a pneumatic hammer. A dust count in the room showed an exposure well below the accepted safe standard, but the dust contained approxi mately 20% of free silica. The Claims Referee was of the opinion that the exposure to silica dust was well estab lished. and the claim was approved as compensable by the Silicosis Referees. Acting under the provisions of an amendment to the Occupational Disease Act effective May 20, 1939. the Commission granted an award of $6500 to the widow and minor children, payable at the maximum fate of 318.75 per week. F*S*M. Recent developments in relation to sQicosis. Lesov IT. Gardner. Ind. Med.. 0* 45-51 (Feb.. 1940).--Certain tentative conclusions derived from experimental work upon silicosis In progress at the Saranac Laboratory for ^ some years are recorded. As a basic doctrine. G. con siders that it is still true that only certain forms of free silica and the group known as asbestos (fibrous silicates) I 6 Ceramic .-l&sfmrtr Vot. 10. No. S are capable of producing fibrosis in a normal lung. The composition of a body may be modified to obtain a desired trend of tome of the Saranac experiment*, however, has thermal expansion. The thermal history al* affects the altered certain concepts previously regarded among re* thermal expansion; curtain composition* fired at low tem search workers as Seed. Inhaled chrysolite asbestos peratures have lea* expansion than the same body fired fibers now appear to be Irritating, not because they are at higher temperatures. Thermal expansion may be silicate*, but because they are stiff fibers, mechanically measured directly on a bar or by the interferometric irritating to the lungs. Grinding them down eery finely method. Bodies with a considerable amount of high* to that few of the fibers were longer than 2 microns prac expansion quartz in low-expansion clay may riiow duneing tically destroyed this irritating property. Even with an tendencies on cooling. Beta-quartz expands on couling average atmospheric concentration of 123 million particles and may also set up strains. The abrupt quartz inversion per cu. ft. of air. no fibrosis developed. If the effect of point at $7VC. may be drsuucrive. Quarts and clay* asbestos on the lung were entirely chemical, a decrease in have fairly uniform thermal expansions, but the feldspars particle rise might be expected to increase tissue response. are variable. Hotel china, sanitary ware, and finer tile Large particles of free silica have Uttle effect on the body, all have thermal expansion curves lying close together. but smaU particles increase the reaction of body cells. The quartz present does not seem to affect them. A The histology of early asbestosis, as detailed by G. does quartz grain shrinks more rapidly on cooling, and it is not suggest chemical injury. Among dozens of different thought to pull away from the remainder, so that It does silicate minerals, only the group of five known as asbestos not dll its recess in the body completely on cooling. are unique in having fibrous structure and in being com* monly recognised as pulmonary irritants. The group W.D.F. Report of Committee on Ceramic Education. N, \\\ varies Ut chemical composition within iuc\l more markedly Tavxor, Chairman. Butt, fimer, Ctram. Sac., 19 Ml than, as a group, from other silicates. Chrvsotiie asbestos 2C&-21 (1940). 1 has the same chemical formula as a aonnbreus silicate, Report of Committee on Publications. John D Svatr- serpentine, which U physiologically inert. In mills that VAN. Chairman. BulL Amer. Ceram, Sot*, 19* Ml 222-23 fabricate asbestos textiles there may be much fine dust, (1940). # hut if the dust Is composed of serpentine snd very short Report of Committee op Research. Axtkcx A. Watts. chrysotile fibers, clinical asbestosis will not develop. Chairman. Ball. Amtr. Ctram. Sot., 19 |rt| 2U-1S Free silica dusts, unlike those from asbestos, cause a chem* (1040). teal form of irritation in laboratory animals. G. describes Report of Committee on Sections and Divisions. M. E. the two histological stages which characterize the tissue Kototna, CAeiVmea. Bull. Amtr. Csmm. Soc., 19 Ml reaction in such animals after inhaling excessive quantities 221-22(1940). 1 of pure quartz or dine dusts in an extremely fine state. Report of Committee on Standards. John W. Witrrrc* In human subjects, only cases of rapidly developing NOas. Chairman. BtUL Amtr. Ctram. Sot-, 10 Ml 213-20 silicosis show evidence of this two-stage reaction. The (1940). solubility hypothesis, however, hitherto rather widely Roentgenologic aspects of broachomycosfs. H. P. used la interpreting silica reactions in the lungs, is de- Docv. RadiJSo, 34, 287-73 (March, 1940).--The signs dared to rest entirely on indirect evidence; It has never snd symptoms of the bronchomycoses are similar to thane been possible to prove that silica dissolved within the body, of tuberculosis and they are often at first thought to be because the soluble material Immediately combines with tuberculous In origin. D. describes some of the more local tissue etemcau. Soluble silica detected in the prominent Roentgen signs of the various bronchomycoses. urine and the blood is now generally accepted as more F.S.M. likely derived from food and drink than from inhaled BOIcosU. 6. R. KAntuasr. Mtrtk Rtpt., 49, fi, 3, 9, dust. G. describes many of the Saranac experiments 23,30.32 (April. 1040).--H. gives an excellent short review whose outcome individually and collectively U difficult of silicosis. F.S.M. to reconcile with the theory of silica solubility. No fibrosis has ever been produced by single or repeated in* soon jections of soluble silica in its various forms. Evidences Engineers and Engineering in the Renaissance. Wrt- of specific toxicity exerted by silica upon living tissues have UAtt Barclay Pajlsoxs. Williams St Wilkins Co.. Balti been manifested through long series of experiments last* more. 661 pp. Price 33. Reviewed in Scitnet ,Yrr mg years; many concrete examples are given. Iotrave* Ltutr. 37 [12| 192 (1940).--p. discusses the amazing engi nous experiments immediately fatal to guinea pigs produced neering achievements produced during the Renaissance. no symptoms in dogs. The toxic effects of quarts have P.G.K. bean more or less neutralized by adding small amounts of different substances, c.g. colloidal aluminum hydroxide PATXJCT * which gives complete protection in -a G4X\% dilution. Coating end coloradoa of granulated materiafa. N'. P. Particle size Is discussed as having new and unexpected KASSRBxaeia (Bakelite Building products Co., Inc.). `t relations with both highly toxic and merely slow fibrotlc (/. S. 24)2.002, May 23. 1940 (June 2. 1936).--A roofing conditions. G. Is cautious about drawing final conclusions granule has on the exterior thereof a coating comprising a from animal experiments alone, but he does begin to cor hardened hlgh-alumlna cement containing principally relate his experimentally derived facts into a coherent calcium aluminaces or calcium alumina ferrites and sub silicosis etiology. K.A. stantially free of free time in amount to produce objection Reladon between the thermal expansion and the proper* able efflorescence la exposure, the surface of the granule ties of ceramic products. W. H. a**mxt. Ohio stntt being also substantially resistant to chipping and wear and Vnio. eC. xpi. Sta. 4Vw, 12 (2| 23-23 <1040),--The stable with respect to a bituminous bond. Ad < > * 'i *v 3 ;'J *$ 1 I :!) a Vi 3 3 y! % I *4 T.1 licea taken of the advanced training centers its heavily (a* ilustrializeti cominunities, showing that there is evidently inaU demand for this field of practice. F.S.M. I, Lead coatetst of human blood. Q, Lead ts i poison. J. .V. M. CkaljiCW. U*t, 238, 447-50. 4t>2-63 (March 0. 194*)).--Tompmtt*s method of determination was used. Blood was obtained from 3* normal people and 50 hospital cases, all wtth no known exposure to tend, and also from 44 factory workers with a definite lead exposure while manu facturing white lead aod storage batteries. The blood of the controls showed a lead content which varied from 30 to 00 Mfin. per UH> cc. with a mean of 57. The lead workers, who presented no symptoms of poisoolnf. had blood lead values mtisi from U t W2 pin. per LU) cc. with a mean of 11*4. Augmented concentrations of lead la blood Indicate increased absorption of lead but do not con* sdtute evidence of ptumbwn; they are a useful estimate of the degree of exposure. Clinical dsdiop must still coaciaue to govern the diagnosis of lead poisoning. There is a discussion of the problem and alio of the value of milk in the diet of lead workers. With a high calcium diet, there is less lead absorbed from the gut than with a low calcium intake. Sines, industrially, most lead enters the body cltrough the lungs, the calcium probably acts by helping to fix the lead is the bones and thus prevent it from circulating is the bloody Thoughof great value, blood studies and similar biochemical investigations must not be given too much consideration. t F2xM. Luags of cement workers. S. Caccviu axo L. Dt- Paoco. Fviia J/Vrf., 26. 7-30 (1040).--A review is given of Italian literature on the subject which stems to give a less favorable picture of the health of cement workers than is found in other countries. Histories of seven cases are given which show silicosis in grades l and 2 and emphysema. Tuberculosis was not found. F.S.M. Manufacture of Bred days (brick, the. and pottery). A. Coctao*. ArtiU, No. 107, pp. U~2l (1030); No. 106. pp. 5-0 (1040).-- discusses the raw products used in the manufacture of fired day products, the formation of clays, and their characteristics and composition. M.V.C. Mechanism of development of lead anemia: IV, Phydochemical nature of the splenic and User substances which decrease erythrocytes, S. Kw. /ear. JM. CdL AV/>V, P, 101-107(11139).--After injection with lead acetate, the spleen and liver seem to contain some specific chemical substances which are able to decrease the number of erythrocytes. K. attempted to determine the physio- chemical oature of these substances which were obtained from the splenic and hepatic veins after injection of the lead. The anemic action of the splenic substance disap peared after heating for an hour at 100*. The substance was soluble In water, but did not dissolve in ether and alcohol; it was adsorbed easily by animal charcoal or kao lin. Its action wan also retained after ultraviolet radiation for 3 hr. FSM, Metabolism of nudeeprotelna In lead poisoning. G. MtcasTii axd F. Molting. Ran. fifed, Ap^icata Lasvro fed., 10,562-32 (1939).--Original research on ten cases of lead poisoning shows chat there is a pronounced tendency to uric acidemia; this becomes more acute aa the poisoning tends towards chrooidty. No relation was seen between the degree of uric acidemia and kidney function, and no such eoonection is likely to exist in cases of recent lead poisoning. ' F.S.M, Nature of antbrmcodn foci. Experimental research. A. C. Savsluni. Foila 3M., 26, 21-32 (1040).--& gives a review of the literature and of the views of some French and Italian workers who are of the opinion that the greater part of the "anthracocic" pigment in the lungs is not truly asthracotic but iron of hemolytic origin* Animal experiments by S. lead to the conclusion that car bon and Iron participate in the common antbraeotie focus; some contain carbon and some iron only. F.S.M. Occupational dermatoses under the fHinals Workmen's Occupational Diseases Act. H. R. Foensrzx. Iltfitrii J/W. -W., 77, 70-65 (Jan.. I940).i--After analysing various sections of the Illinois law, F. concludes that **any skin disease may therefore legally be an occupational disease in tUincb." F.M. i Preventing economiser corrosion. F. J. fiUrrngws. B'iL tfjjvivtrr, 46 15731 :i32-34 U04UK--M. discusses the causes of corrosion and gives suggestions for the maintenance of the economiser. ILA.iL Priceless possessions. L. Gugxsumo.* *V*u. Safety AVer, 41, 25-27 (Jau* 1940).--There were 1543 cases of compensated eye injuries in New York State in 1933 and the cost was 61,165,00(1. Of these, S0% were caused by foreign matter entering the eye and could be avoided by the simple and cheap method of wearing gaggles. Yeatila* 1 tion controls are needed for eye hazard! of toxic dusts and fumes, and in the past yeap the Division of Industrial Hygiene has passed and approved 2000 sets of plans for such control in factories. Special goggles are needed for protection against radiant energy, and fadguc of elm eyes can be lessened or eliminated by proper ittuminattoo. G. discusses these sight-saving means and methods for pro- * I I * - moling their adoption. F4.M. ; Two fatal cases of pulmonary asbestosi*. . C. J\ Yfcmuft. Ran. MM. Appiicata Lizuro Ind.. 11, 25-52 ! (1040).--The first of these cases concerns a woman who worked for thirty years in a factory using asbestos in the manufacture of cord. The second woman worked for sevea years la aa asbestos factory. Her susceptibility to colds increased while she was working and she suffered all her life from bronchitis and asthma. She died at the \ * * J ? ; age of fifty, with symptoms of a lung disease, eeariy thirty years after having stopped work. The autopsy showed interstitial sclerosis or the lungs and asbestosu hodttt. - F-S^L : * ' I Unemployment benefits no bar to workmen's com- \ penaadon. Anon. U. S. Dept. Labor, fifoehUy Labo* Am,, 50* 670 (March, 1040).--An employee .receiving unemployment benefits under the Unemployment Com pensation Act U not disqualified from recovering com pensation for the same period under the WorfanetCs Compensation Act* according to the Supreme Court of Michigan. . F.S.M. SCFAXATC TCBUCATtO.VS . Basophilic Aggregation Test (for Lead Absorption and Lead Poisoning), Anon. Ohio Dept. Health. Adult Kyg. Div., 1040. 7 pp.--The technique and interpretation of results of the basophilic aggregation test are given in a concise form. F.S.5L Legal Aspects of Engineering. TV*. C. Saoccs. John , tVQey fie Sons, Inc., New York. 631 pp. Price 54.00.-- This is a direct application of the case method to engineer ing problems, three hundred casts being selected alter6500 legal cases actually dealing with engineering problems were j carefully analysed. Cases dealing with compensation are of the most Interest. S. give* a general dismission of the subject. Cases are given to Illustrate the following pmnur: 4 elimination of defenses, hazardous employment, employer- employee relation, accidents arising out of and in the course of employment, proximate cause, award, dependency, and jurisdiction. * FfifiL - I I Manual of Industrial Health Eirtrdi- J. B. FrcxLix. / Service to Industry, West Hartford, Conn. 175 pp. Priced 64,00.--F. presents methods for the evaluation of talustrial hygiene exposure resulting from many dusts, vapors, and gases. The first chapter gives principles which are basic procedures for making surveys aod describes sam pling devices. The other chapters are given over to the ma terials or groups of materials which may cause industrial disease. For each substance, F. gives the occurrence and . uses, certain physical properties, the clinical symptoma tology it produces in man, the physiological responses of man to various concentrations, the concentrations allow- i able la the air of the workplace, and a simple method of estimation In air. Numerous references are given. An ap pendix includes useful constants, formulas, and . instruc tions for the preparation of standard solutions. * lactic and molt tfRcitnc vent* Burntr% Tor t*try gal Cal flgrntrj with Ofl.BurruM mcorpomtd Cat Burntrt ttktftf two (tut a(ttrnittfy PflWFR ISIS FCntflMr CO. jfgggfaSSV&9ST&Z HURST, NELSON & CO WOTHERWEU. RAILWAY ROLLING S OF lve*T OCKIUPTION t'4 C**# * \3< f** H*C ^mhi, IP. watrtoMt *CO#K bS*WmHfp`. |(w|t*f IRON & COAL TRADES REVIE 'LftXDO*' amma . isso Iron-Ore Extraction in the Midlands* OPEN CAST WORKING AND UNDERGROUND MINING METHODS Of SURFACE WORKING Tbo ela* of HU aod data varies alac ALL tamatoo* to thn tfiffiaoda woo TV* tppoadei ttwA^tba of iwMn atttc* with tho dwptk Ol ovibuidna. riweo the eiMUter aaad ndu generally originally fat by band either at out* tlea la tb Midland* ha* b**e taktn from the depth ef the woterie* U ha wc cropt or oat more the* 13 to 30 ft, beloRweport* of the Commits** o* tha Restoration ean there/ore`talk al a ** aarmei ** to* euriwee. The latattfttomont t ucb land be agricultural uao immediately alter the working presented no difficulty. No (rtit Datut q( subsoil W been dfatuxtod; tbe topsoil wo* (needy thrown on 004 id and #f Load Affected by lroa Ora Working. and deals' with method* of removing tbe avnri burden, and wtnatag In undarfroood working* and data tar a particular depth at V it (a uadafaioad that only a my g* tionshlp fa maant. Tha feaaral uo waiter of Importance in qnuoonUo* coato at fawWog. Whan tha cat fa a Anal gulfai la wit. Thfa Mf ha than returned witbout asf coal .lor houlap. al 200 to 300 f*. wid* and 00 It. do JU tba tutu ol ton`century tmaU turn uTty fetfawiat up behind drafUna A and laud* map lor* * coaattarabW di&kulty I oseevaton with a thort-una jib were fatto- fef the ironstone taco wagone B. Th* face at X> to tbo ftnny, pertfeufarly diteod lor too purpoac of motoring tbo over gradually recede* a* tho ironstone la recured. rcstorattas work. burden, but all land vu *UU rcatoetd by hand. When a quarry craa about to become too deep for restoration it wme abandoned or tniood. Excavators were then Introduced lor The workiag fa Ilka a norable cliff. (3) A thert lib ncsnhr mv bo uaad I* eoajonetien riu a ccureyor ** In Fig. 3. The excavator A roouee* *v*rburden from the (ace B and then emptlea tka load lota a small Local Ob)cdo9i to Large Cse It fa the oparatiaa af that* mach* boa alarmad local aotoiaa aod wfafali attention to the whole '` Mooring tot ora iUall. la tha azpaoaico ol track. *c dumping Warn. # tha stout-fretted warklNf ol faonrtnaa la abb coontry. development due to the War. tbe American cirtvjw at C. Tala cane op to the ether end reaction to the coafac of tha bagoee fang jib and mechanical differ with a wide at D aod Ufa tear. Tbo function ef the con ku been Unmutuatfaf are not dnmptng radius waa Introduced. About this veyor ft therefore to mere tbo dumped near, It fa won thatlraaatooa waa waa to to# eeme areaa ware drat left uorastored. This waa. at fleet not to much due to technical diAouttioe at to a company going cot of bualnoaa. tv fttWw Wta MfVi *tii, la tb* harden away aa far a* poariUo aa that tbaro b aa deafer.ef tha aewy wfcfeh fa removing tho ImatUM baronlag bannd. The oyetourde* fa damped bp tha conveyer In a rid** and furrow larmatfan similar In that wWeb mstto from tbo * of o la*( flh auaooior bat In 0 vashor low um sad ft fa wginri ; oortt`, II n Mow of tho deeaatotfof co t-o----b-e-iamnU* to eider method* a e00a0*r1n7 of pat cower one*. If it b polo a^` faitth0a0t Jtmmn* M mo ho ft depth to tho old co* mat nbtrrica, SUwerta and Uoyde left fleoatoatpo moot wo*y Uaa. "--------------J --, if tho prodr rmrtwdcn ifaoioiJ U*)^ .-Trx"/ .0. --1-(4-r--un(Stt' onc \ntttutvv Fin. L-^Dftao-Litft Maroon Sornaormo. aad coon to Northerns. fine* tbop were Uto> (3) Tho ororbnrdeo *w bo pul to It. they noald Ineonb now moth mmwe th** found all tha areaa of easily get or* damped by % leag^th esoaeatoo. ouWJ abolish ar modify biQ and dale, ceotnlled V/ other Iru. aod thop wet* forced (Kg. A) .are e/ ^-Kcuh. wL aaem engineering gorefawoioiitt u* tkey app. to loau area* ol deep oWbardwa. Tb*p began These machine* are the Large** In Europe, and Commlttoa from u* oridenro put bei mth on tbeae with aa electrical irauu/ tiier karo an eotpot ol aboat 300 tea* per hr. ienludedt*- which, with * I cub. yd. bucket (1 cub. pd. each. U fact tbo whole area amuao* tbo aapact (I) An attempt might to made to lm represent* *07 tporoulmalefy 1 too), a dmpa ef bariag glgaatfa lurrowe. which too locally onearaiar. Tha preseat performance a mg reiiut al UR ft. aad a dumpiog bel|bt al known ti "BiQ and dale.** Th* ridgee conclst function of tho rodltta of tho jib on m fv aouM deal with ooerburdon up to about pradamlaanttp ef snbaril, ud fa them tha to^ ugto of repoee ol tha dumped *oi|. 0 It- io depth. * writ It Ifretnerablp lost. The elao ol thw* cauM tkeoe tw* farson aso Isad, that Ironatetn fa mm bp a aambar af different forrowe depeadt aa the rite af tha narew aeed dato fomatfoa ocean. II th* Uogtfa . achiaca erkou oooratfaa* have somewhat for the eacararioa. Wbera tha targaet naewfaa could to waring sUghtly wish each bac different affeeto. Thop inriodo the 'draglioe era ia ate, the distance from craet to crest fa then hill and dal* of tho preoent vtich wurln on the principle of a rak; tho fnwa 40 to 3ft ft, tW dtfMh rarvtog from 10 wuhl not h* fermod **d a ttsrfouo wo wonwr or digger'* with a ahor* arm (the ft. to IA ft., bit whore smaller exemratom hart which, if very irregular, would be muck " Jib M) duapiag oa to a c*T*per ar wagon*; been need la tho peat, the crest to craet distance level. II tto length of tb* jib wen : tbo Icag-jlb oscarator which dfapaa*** with the fa botvoeo X ft aad 30 ft., aod tb# depth Iron however. 0* a so give a choice af fatter, and the Lubeeker (land) dredger which U ft. to shoot 10 ft. The shspo and rise al tha which each bucko* could to emptied, U n* dump mad sr other verp tight *mt ooenlp. htlfa and dale* iapead aot anlp an tha ippa ol of to* entire machine, which l* tire* The dredger ere*tee M probfea al lerrilieg bo* MSchinarp used for pnttfag tha material across, 300 ton*, would bo Ucreseed to aa tmp man al tha number of waaR heekat Wad* but aim aa tha eagl* af tepase ef the dumped eaten*. Further, If any attempt wore dumped, but for thfa rooeoa It fa oslp efldeat in watariaL The ootural acgla of repast of up dump material anywhere oeor the eicai mod or tight soil. Them are a groat number of particular mil cofPposltioO will geoeratly only bo aogto of vopooo of too lipped wit w*i fombieatleaa al there meehiew. with or without found where it fa free to trickle; es the that to* msrttor (teelf would to buric feod labour, which are uaad la dlffereot gaarrioc. lope el the dumped material sUotohuif down (tl * new coAvupvf might to Jtaie nd it would ha dtfteutt to gioa a cataplata to tha guarrp flo*r. M*aaur*m*nt* *ra ofun position of which could bo altered Ut*< mcaaet of thorn. Tha following are deecrip- mad* el this aagfa far different tutorial* and faod placed on fa by a smell carevat tfaa* al tho work In three guarriet which are "umbiftetioas af matariafa, becouea it. ia thfa witness aujtgvttod this, but tbo Commit npreifatatira ol certain typical ooodltiana. * iegfa that determine* th dfataoco hetwoea tho fa aa unlilroly rferefapmeat. The pre, (D A 1| cuk. pd, dragline al A (Fig. t) r*. top el the dumped orerberden *ad the faro al reyen caonot to used where three fa " the Wt orerburJen (including 9 la. af the encaratleo. fins niusnoiMte ahew (hat of tMwrtordeo of more too* 40 ft, b ?cfut> dandd_a_tda_e"p_o_fso_itms_ia_Itr_ioa_nt_w_Chiicnh a is rtehrepq. jsnhra*ltlloiwl an avenge eagle of repo** fa l|-horiuouit* to I vertiutlp, Although It a*p be Batter in bmilder too strain which would bo tapoeed *. ana of Uto conveyor when tor truck w*i to tha fth cob. pd. dragtias at C. Th* opara. clip. w. here thera t* a .good deal af slip..ping_ aod away from It* point of enpporv ft v non fa then curapletad bp a toenb. pd. *toam tuepar la limeatoto. TV aogU af actual hill bo tacy, toaref&r*. to design a convey - - -- . aad dale fa nearly alwepa flatter than tbe angle would product batter mult* with aa *t S****, ll*or, tetosa. ol rw.poio ,prorper toreurn tthl * mater'ia`l '1* par't'ia"lly spread sa il it emptied frsm the eicamior. of 60 ft. er mem in depth than era tho presoot oo with * overburden of 336 * Tke Iron and Cool Tracies Review September 8. 19. Fatalities from Silicosis and Asbestosis iE/ES i aAeiaat enbetitwtai for siUeeewa wsurinii THEIR INCIDENCE IN INDUSTRY tain prate***. Praffrw baa lm ad* . dimetia* j tha fallowing !< * __ tl , ,. . * nMttii la iImi U ia can* The problems usocisted with iuIcmu isa ubcstoeU ftmonat .Indus!Ha] wk|nl uHaam to u* pnemn workers art receiving dose attention. The former has tendd to Increase. *llw,iy hr *j J* Uu. OB kW, IB fa nrcrat - SJSiSS ZZ ft CSfti ' ifl|! (4) Ml iIIIom MWUI hr W A SECTION* of the JUsuil fieport* of the omihiIn mi Ou W nf*W| iU aillr* Wtefc m4 U Ik* h `mIH'I of atetii Chiif Inspector of Fsetories dssUag of **! famacea ar aumia o a pat *?* ^ **"1 arttb health refero to the of dost T*** ** <vi**r hi * and Its effects, ittdudlar sUiooab nod * * sst. sx'ttit'ats: sS^H&HSS?! "'fr^^T1'*,1 of JMb. fawn th. mo coiiom. which h* tjT^uur^U* r___ /"*. tT* W bMO flam sod brought up to dsu. Thy iaC ta tha fwpactar's kn^Udg, IsamlfatMl Cfures hsvs been cpecuU/ awful from tha during tha,Nin la gmutmm/ Tba Bgirae gfrao prarttrol point of daw in SUt| the iwtolU- vder ** OtW Cnsei-f Fibrad. - * tiia mom tkm of mevsntfvo me, eUndsra to procatwo TMSi 5. tivs !3*V SSJ-.-5S.ITj ..!?! however. Is the trend of mortality rate* from pl<ed *y the aearUiy ^ tha Jlogmrar 9iMfsl. uucM by a tpatial Oaasa ta lb* pump thrf* ditanaw with or without tuberculosis, jjJjj fw^rJETtir^thl k ! nimd 0f "T*?*1 fcf * *`"h which <U wh.B compvijM I. ,,1. .faif rSS%A^"aT^Sta Sb* * "un'Wf ofy.nr.. r.Hwt S tfyhg-f - J ^fa-lM.*h fa. M---C^. ^1*,/Sr-JV the preventive measure* InauUiO. coy this sq<J It {* v*U rocofnimd that Abram aiay ba du* ' p--m k- d-livar* dd af tbs eons th purpoet. companion of tha fiyure* of two to own aihav than Iha labatatlaa of diut. aa(| nur wiitan ts caarawd by mmi sucettsiva yaara is of no valua ood aomatlmt* Tlwa ratumi ara jailttpvarabla wara, frwa thaa arf^rrd daaibla bow ipa* ta a Uoa i Riiiltoding. tioi*. thay aravlda tb trUnS p*it f .tt*l pit*. In VU%. t* Wt. Imetlwi #t*. T*M I 4*0v Jaatha atwibotad to iUkotli rarth^r taraatfgillaa vhteb (w.-fiathll a-ar _viTibaLo__uai *tu-bl--i-m---0l-pii-)* Jd_a_rAiaLf. tIb.a.. laloaftaiQkllaarliwnoatlea. prariUta ralaabla 4v.icttauinbot.brJaoiav_tt_arar;a_ mtb.a p<pa Lttaa1 raaca U cerr yi-paU*oa daafJv_ i TiiUfiUftm--ttsiWmbmt f~rn r*~i*dOa JCaar* immflmmd Zd SlUcoala sod Aabestoeis end Cancer of the- wd-atar <* into V VmlS, Lame vme a! $ taw ptf me. Tba w 1UMI. '_______________________ r. ^.n Ok. mwlUm iuW..^. !"*""' ! "VT Ohaaaa aaS kdaairy. im f loan Mnsnbi Mwik..] PmUfy. nmmCkiwi af ffawiMiatWdfMMSewafa.m. rlnf .. l*3T.; IS3L IS 04 {it <n mo^leal pablicatUna that thara la pama rle* tiowbip Utma tflicwU ev wibattwla amt tan. rev af the k*. n_a_dl--tb-a fBf_nraa Tahra#floanbaleatl.aaore-i-t,7eaa"dt lA7yvoe_mt.ltwU,a.-rr-wna--#r?. 2... _TMrtdh.ethAavlpvtnharaabtwtatiretyenda"adfb*tfb"faa*tipriTMlyuacidaamefainirn1* i the ntn bnwb tbe abnlaa at tha dtlif af tbv vp Tbe Mail CDAtaiaa taa nuteb watav. Wwe fra^tW ** *"* ta tbe bell canvaya ittaemba waotrnar.ad *b wider thantnapupa*|avraaeatiet eIratb*etignahMt. twi^ h-i u** fin^rviwbaarr doaawvnntuarraaad aann aa dnityfiwft hwbeena mmm .. Vac4 erfmOne *. .. bad blast-- .. SMOaditiaAtbM* 1/U 'itsa Itajar nalnta which will hara te be wbtled ares 5and-Drylnf Oevtce PmwHMhww>h. UMkWta Jo** TU M^w.ur >hl4; w^tl >| * hiW| oiRtir #i At Itil Ruiif{f 4 nrti il nid to i t/ vtltf* Jlf ftfflUlfrVI 1 a* er ta pradoe* Ilf U tbe tatter, da either af from tha Cum Staaa. Ate*, and awl WlSl| ., 8raafae pavdaracj aimuitui* a/ .. dtace 4 _ cancer? ' _ . ... rallaetarf ffam th# Tiupedav*t recerda. K eara ^k| *cb b kept in place by fc 0mm nir (Tripafl)., Abnaif**vbaai nan*. farltft .. ., yiflxo-- iiwrane , Shlidiwhl wilhaand CtactKcUa Mad ha# been IndtHted In whirh n ped-martem vnamU *nm -Uui Mfferatad -itb { in. Wei. satton at Wn *,ada. Wt J iriftn u ^ af fL p* AfM*f 043 fatd caraa tn wfabh tiUctMu ar Ttirra rollar* of sqnaa<a ara pbcvd cqaitli caicecb with ahtftefo*u >u pmanl, eawr of tba npper bU aorfaca. and a w T2df^i I? ** ^ S**V FlKid ** ^*S tbe btit tn eanh). Of thwe M, (a IT It wae nwdrv*d that utiVir a It b carrbd ferwaicL Tba Craaha gnaifyit aof U* "5!? ftf d.**tl>\ and pmnf* balp in the d-ntanof af tht U . ailjeeab ar tiiliwb with tabarvaleiln. ^iu* tha ilee in the tmy* aJbw* wtar Amr* W dantha which ware Iwwtlptid dur* k-t ut tha TnMafwnlaf (aawafa ZX2:------- One CaadlMlun^ . but the wma pwiof* awitf te the praaihilile af n% ,,* imief from th* drrlnj bv * * Y#ean-fed ***"*-?"?*b ?** wof1>T ^ IT ITT telna by ralatae apprewmaUty 10 per o water. Tba and te ddi*red fraoi the . . tha dryinf'baU dlract en to a JWn. tra AIM TtoaMef .. - f tbaa lurnnia Sfimas rafli 3013 *?. "*** uWtT< m "TT* bak*f. Tbe kali conveyor dnitn th. # H. hi M K.iuuli*ur(<wb n. t****- m * fT'.'TV-'- 01 U^** MM < tu. MlT bMf dr U IS. In it wa eewddrawd that th* cancer waa h- mtiti. I * lg7 jy*****4 ^ * Tbe land it dtitrared by th WU ranrar 1S ar Mbatintia with Anbrnlaab. U to dear fn tbrae a aedallr ranrirwetcd knnker baldt. *"! niivt(r IjOW tarn. On tha a*d#nide a^Mled 1-iniry m| callratien f data and W(lk|^ ^ y* ll(,^, ,,lt inn,4 TaUl i iffiaaSa 391 sss 41 | 430 aadiwtlM af aw tneidanca and Jfa diauibnimn ,,wI #r tfct%,rial rapvway gr **CW**,T befart candoaiMa can be ^ haine tWirared Irani the rape. 0 - . .. .___ . , ___ ibla there are 7 thntai whkh dtitiwr f Th* Mpartnori a* # # rarafni pra- (hf h^ket*; tha erenUtar at tha Mhim OwdteUl 134 |Stt S4i 1 oy nx iut four fvnn, tnevtbar with Iha indintriai T[!^orafVM empkadrad by iWfii |h-t# ^Mronieff th! aaral wnw ta iha can# la which B*krd-*ya *V*".A*^1 u t* af a tiaipU type, nad U kept ia plat z asL^^irrsr.isiic:***f cybaiteitat hot what appaarad to TM *+ -oaiybt. A aaa-ton caaadtv Ihs rhraraiialdy.M Ibnar-f#nattiuwty Lr#ara*. tha caaaa af death an*d* sa(fwrn another newne lian which illticowa. tnlwmrra- -tab MdtrtMf -* .wM.tl iifi_|_|U____I_^_n_.r_it_u__d__I_.__sii_r.i_tBjd_M__rnil *tih__. _p_n_- iUn tna W,WU*- `".Vm*1"4 * ,,en"* 5,Ml ",p" tire iwcttpMKw-l history tn raeh can, tha ry Subatimetoo Of Slllcfftia by Noo-SHteteus 1 . ^ . . . . . _. widM---p--r--a--a-i1l .n.a..t.n.r--* af .tb.--e rU. kt wenld ha Atfll Me-re evhlrmi. Frwor e^xa"'mPp*ler, rirvifrroortworriaecs* Ifmiwltr*autrvirc>* yR pnct*- ia -M---e---t-a--rPuiele-tran which the tib antpat*tn .f^ieabr to Jnly ef tiltcntie ( jI.C,4-.NM44A nunririntiJnds r;(IH|.MWI. lm*~ tin pJmu.tk*J". levtwte aroaagtl tba AS faUlltiei three wba^ Mriott* *ed nncantwtUbW r only pavtieUy ran. i--oi* In 3d>. ***** iK.ttt tnn^ " _- utilsM*. the praraatlnn nf tilkosii Um eith#r | U0.Y91 ira* ia Jti*. I*M. A teUl M , *i. ja autetituliaa hy harmIces nuutiaU ar at tha nacre were hi hlsm o Jtiy 41. to *** U ftAlfcW to promote ^<*9^ )^ 4^ COACOffltof odwtrio) m4icfa* 4nJ trumtS To tK>t ti4 H *3) cofttaU r` M1 Nprtir dlfttil, proton tatioits* topathor with ,lwrt* comment*. TKo oditorUf pol- CT h to tcour9* frank dfrctfufon. Om this b**li contrtbutMio* ro feWUd. *$. 0 & F*c Oft 476 Tk* J;. v rt w titftUt urt fa cfcocfc fag tho ocoorocy of df# pfhM, hoi fa Q othor mptth #rtkU opinions #f which tipftnlm k nOowsd r th opinions of thoir authors--Ili# ndltors rosorvinp Ip |) tn tho right to oommonf on tho Mm*. fa tho cw root or ooy swhsoqooot kcuM, m <hoy may ho facBnodl TKo Journal of Occupation*! Dliustt and Traumatic Surgery With which arc consotMatctf wThc Industrial Doctor" and "International Journal of Medicine and Surfcry." attg.r?r:.>:i /,, :%*.v :.y rL-jjr^r^Yh *yju^j^r'T^xrr'^f^ri The Science, the Law and the Economics of Industrial Health /oiume 9 ^a"&ri------- FEBRUARY, 1940 TM^TiTiTfrT~`11 r " Number 2 General Motors Corporation Medical Conference --Dayton, Ohio, November 2 and3, IQ3Q-- rHE recent Medical Conference or General Motors Physicians, held at the Biltmore Hotel, Dayton, Ohio, November 2 and 3,1939, omprised five meetings and 18 presentations. The Program was as follows: Director, Fisher Body Lansing Division, Lansing, Michi gan. 13. "Study of the Factors of Employability, Especially Disabilities and Infirmities of the Elderly, and Problems Arising from Employment of the Same," Georgs A Paul, MD., Medical Director, Hyatt Bearings Division, Harrison, Tiur^day, November 2: yyTOBNlNG Session: Chairman, M. M. Skater, MD,, Medical Director, Frigldalre Division, Dayton. I 'Recent Developments In Relation to Silicosis," - U. Gardner, MD., Saranac Lake, New York. A Plan Tor the Conjtrol of Tuberculosis in Industry," (ax Burnell, KD^ Medical Director, AC Spark Plug ^vision, Flint, Michigan. * 3. "X-Ray in Industry," M. William Clift. MD,, turley Hospital, Flint, Michigan. . 4. "Preliminary Report on Hygiene Studies of Weld- tg,n L. B. Case and V* J. Castrop, Industrial Hygiene aboratory. General Motors. Detroit. \FTERNOON Session: Chairman, A L. Brooks, MD., * Medical Director Fisher Body Division, Detroit. Hew Jersey. * 14. "Early Diagnosis of Acute Appendicitis," C Rush McAoam, MD., Medical Director, fisher Body St Louis Division, St Louis, Missouri. AFTERNOON Session: Chairman, F. B. Wzshard, MD., -** Medical Director, Deleo-Remy Division, Anderson, Indiana. 13. "Relationship of the Length of the Inguinal Liga ment to the Occurrence of Inguinal Hernia," C. M. Htzx- ekbraku, MD,, Medical Director, Harrison Radiator Dlvl- slon, Lockport New York. '' 1$. "Hernia in Industry; Review of the Cases During the Past Ten Years," R. L. Johnston, MD., Medical Director, Inland Mfg. Division, Dayton. ' 17. "Antiseptics and Their Actios," R. M. Freeman, MD., Medical Director, Linden Division, Linden, Hew 3. "Recent Developments in the Occupational Denna*es," Marion B. Sulzberger, MDv New York Qty, 6. "The Course of Disabling Morbidity among Indut- ial Workers, 1921-1938," William M. Gatafcr. D.Sc, Jersey. * 15. "Management of Fractures of the Spine," A W. PoBonsxr, MD., Medical Director, Electro-Motive Divi sion, La Grange, Illinois. ` ' S. Public Health Service, Washington* D. C. 7. "The Industrial Nurse," Harold M. James. MJD* Except for Dr. Sulzberger's address, on "Recent radical Director, Delco Products Division, Dayton. Developments in the Occupational Dermatoses" 8. "The Doctor's Part in*.the Personnel Program," coRGt A Coburn, Personnel Director, Delco-Remy Divion, Anderson, Indiana. EVENING Session: Chairman, Walter M. Scmtson, all of the papers given at this Conference are in cluded here in full text, in the order of their places on the Program: M. Dn Director, Kettering Institute tor Medical Re arch, The Miami Valley Hospital, Dayton. 9. "Relationships of Industrial Medicine to Private Recent Developments in racUce," Stanley J. Slxccr, M.D^ Chairman Council on dustrial Health, American Medical Association. Relation to Silicosis 10. "Unfinished Business," C. F. Ketterctc, Director cneral Motors Research Laboratories, Detroit LeRoy U. Gaju>nth, MJD.( riday, November 3: Director, The Saranac Laboratory for the Study . ORNING Session: Chairman, G. L. Biro, M.D., Medi- of Tuberculosis, . ijjfjyl Director General Motors of Canada, Ltd.. Osba- | rio, Canada. ! I* : *i Practical Approach to Supervision of Mental >alth in Industry," F. S. Parney, MJ3, Chief; Division of I dustrial Hygiene, Dept of Pensions and National ;alth, Ottawa, Ontario, Canada. 12, "An Example of Industry's Participation in the itl-Syphilis Campaign," P. J. Ocksner, M.D.. Medical Saranac Lake, Hew York HEN your Chairman asked me to speak of Wnejv developments in the field of silicosis I was perplexed because all but a few of the pathological, clinical and diagnostic aspects of this disease are now well established. I realized Pag* 46 INDUSTRIAL MET 'IE February, 2940 , that you had become better acquainted than I with in the uonchioles. As collagen forms and con the practical problems of diagnosis because you tracts, the air spaces are obliterated by scar tis were dealing with them every day. After some sue. In experimental animals, at least, this change deliberation I decided to tell you of some of the is not a progressive one after cessation of exposure experimental work in progress at the Saranac to the dust as is the case in the response to quartz. Laboratory and to permit myself to speculate as Perhaps the reason is the deposition of the pe to its significance. These experiments are incom culiar iron-containing coating on the surface of plete and no conclusions are possible now, but the inhaled fibres giving rise-to the characteristic perhaps they may ultimately lead to a better un "asbestosis bodies.'' Dr. Timothy Learv consid derstanding of the action of irritant dusts upon ers* that the resultant smooth rounded ends of the lungs. - these bodies are no longer capable of scratching ` As far as I have been able to discover, it Is still the delicate surfaces of the air spaces. true that only certain forms of free silica and the Finally it is most suggestive that among dozens group of fibrous silicates known as asbestos, are of different silicate minerals only the five known capable of producing fibrosis in a normal lung. as asbestos, which are unique because they are Many other silicates have been Incriminated by fibrous in structure, should be commonly recog roentgenologists, but when autopsy specimens nized as pulmonary irritants. The variation in have been examined it is discovered that there chemical composition within this group is greater Is associated chronic Infection or that the inhaled than that between them and many other silicates. dust contains significant quantities of free silica. In fact chrysotile asbestos has the same chemical I shall' first compare the action of chrysotile as formula as a non-fibrous silicate, serpentine, bestos with that of quartz upon experimental ani which is physiologically inert. Obviously irrita mals and review considerable evidence bearing tion would seem to be associated with the physical, on their respective modes of action. A few of rather than the chemical, composition of these these observations now have oracttcal significance; minerals. -* others may prove to be quite unrelated to the One point of practical significance may be indi pneumoconioses found in human beings. cated by these observations, namely, that very finely ground asbestos is not dangerous. This FOR the last year or two we have been coming conclusion has support in clinical observation, for to the conclusion that inhaled asbestos fibres it has long been known that at the Thetford mills axe irritating not because they are silicates but bethere was no clinical asbestosis even though in cause they are stiff fibres which mechanically Ir former years' the atmosphere was very dusty and ritate the lungs. Unlike the free silicas, these the dust was extremely fine. The fact that fabri minerals will not stimulate fibroblasts in any part, cation of fibres of the same mineral in American of the body; only those in the lungs are affected. plants could produce disease was one of the puz It was inferred that these organs were affected zling features of this disease. But these experi because the movements of respiration are so much ments offer a plausible explanation. The fine dust more rapid and continuous than those of other in the mills is composed of serpentine and ex viscera. Then it was discovered that if asbestos tremely short chrysotile fibres; that in the spin * was ground very finely so that few of the fibres ning and weaving mills contains many more long were longer than 2/* in length the irritating prop fibres. erty of the asbestos was practically destroyed In Ihalation experiments with such fine chrysotile asbestos have now been continued lot three years. N THE case of free silica everything points to achendcal form of irritation although the solu No fibrosis has developed in spite of the fact that bility hypothesis as now conceived is not com an average atmospheric concentration of 129 mil patible with all ,the observations that have been lion particles per cubic foot of air has been main made. In experimental animals inhaling or in tained. In contrast 1 would point out that in a jected with excessive quantities of pure quartz previously reported experiment1 one third this or fiint in exceedingly fine state of subdivision, it concentration of long fibre asbestos dust produced can be observed that tissue reaction takes place well marked fibrosis after about two years. in two stages. First there is an acute inflamma If the effect of asbestos were chemical, one tion resulting in necrosis. Following it there is would expect that a decrease in size would ac healing with fibrosis in the form of a granuloma celerate tissue response. With free silica large whose end product is the silicotic nodule. The particles have little effect, but as their size de collagen laid down by the connective tissue cells creases cellular reaction becomes more vigorous is modified in a peculiar way analagous to that in and even constitutional symptoms may ensue.8 the tanning of leather, and this is responsible for With fibrous asbestos the reverse is true. - the characteristic hyaiinization of silicotic fibro The histology of early asbestosis does not sug sis. Incidentally, leather has been'tinned with gest a chemical injury. Even under the most ex silica and sections of such leather reveal that the treme conditions that can be created by artificial collagen has undergone a similar hyaline trons- injection there is no preliminary phase of tissue .. formation. In human subjects only cases of rapid necrosis with infiltration of leucocytes as occurs ly developing silicosis show evidence of a two- with high concentrations of very fine quartz. The stage reaction. In those with ordinary chronic connective tissue cells merely multiply very slow disease, degenerative changes are slight and over ly in areas where the asbestos fibres are caught shadowed by the formation of connective tissue. ry, 2940 id con* ear tls* ge * -are quartz, the pe* (ace of deristic consldrads of itching dozens known iey ere recogtion in greater Hcates. lemical entine, irritalysical, * these Indi ct very . This ion, for drTMills n a,, -ad :fabrilerican. te puzsxperire dust nd ex2 spinre long Ints to a solut com* e been or in quartz sion, it : place 3xnma* lere is roloma . The e cells -.hat in jle for m. ..*** trans, rapid- I t two- I hronic I over* i tissue. . ' VOL. 9, No. 2 INDUSTRIAL MEDICE Page 47 The solubility hypothesis is based solely upon ticles of larger size and it has not been observed Indirect evidence. It is known that colloidal silica on injecting suspensions of several other minerals Is toxic and that quartz will dissolve to some ex ground to the same particle size. tent in slightly alkaline fluids of the same pH as Symptoms are initiated even before completing those of the body. But it has never been possi the injection by the onset of rapid, labored respir ble to prove that silica has dissolved within the ation. The skin of the face and extremities becomes body, because the soluble material is immediately pale. The animal displays uncoordinated mus combined with local tissue dements. It Is now cular movements and sporadic convulsions ter generally accepted that the soluble silica detected minating in death if the dose Is sufficient. When in the urine and blood probably comes from In- smaller doses are administered complete recovery -gested food and drink rather than from inhaled takes place . . dust . Autopsy of fatal cases discloses an Intense en gorgement of the spleen, omentum and subperl- WE have made a good many experiments whose toneal tissues which are deep purple-red in color. results are difficult to reconcile with the solu The liver, and in fact practically all the remainder bility hypothesis. They do not necessarily invaolif* the body, is almost bloodless. Counts of ear- . date it because we may not have all the facts and vein blood show only about half the number of do not know how to Interpret them. For example, leucocytes present just before the Injection and we have found that cellular reactions begin within a corresponding reduction in red blood cells. The 15 to 30 minutes after injecting fine particulate blood no longer dots. There is no hemolysis. sDica. In the test-tube traces of dissolved silica Animals that have recovered from one reaction are only discoverable by an exceedingly sensitive seem to acquire ia tolerance so that in some in . colorimetric reaction after 12 to 24 hours. Possi stances at least twice the former dose may be in bly "vital" factors may accelerate the process, but jected without symptoms. The degree of toler no means of evaluating them has yet been dis ance, however, varies widely in different indi covered. No one has ever produced fibrosis by viduals. , single or repeated injections of the various forms These symptoms are not influenced by the in of soluble silica. The effect Is apparently not due jection of adrenalin. They are not reproduced to the quantity of silica dissolved, for many of the by transfusing the blood of an animal dying in - inert silicates in vitro are those soluble than quartz shock into another one of the same species. They or flint. Evidences of alteration of the surface are only exhibited on injecting suspensions of - of quartz particles long in contact with living tis quartz particles less than 3p in diameter. They sue have thus far escaped detection. are not produced by -injecting the supernatant . In years oi experimenting to discover the salt solution from which the quartz particles have -mechanisms by which free silica exerts its pe been removed by centrifugation. The severity of culiar effects upon living tissues we have re the reaction does not vary with the age of the par . peatedly observed evidences of a specific toxicity. ticle suspension, although the amount of soluble Guinea pigs, injected intraperitoneally with large silica increases on standing. doses of fine quartz particles are often obviously The toxic effects of quartz can be more or less sick for some hours. When Mr. Cummings and effectively neutralized by adding small amounts Mr.* Redlin* were seeking an avenue for the of different substances. Colloidal aluminum hy quantitative introduction of silica they tried in droxide gives complete protection in dilution travenous injections into rabbits and discovered of 0.03%; colloidal ferric hydroxide is much less the method which we now use as a standard for effective. Animal charcoal cannot be injected, be ' comparing reactions to different dusts.- But in cause it flocculates with the quartz and produces cidentally they found that these animals would emboli. The finely ground metallic aluminum, die very promptly if the unit dose of quartz par- used by Denny, Robson and Irwin4 in the preven tides were tod large. These deaths were not em tion of silicosis has no influence upon acute in bolic because they did not occur -with large par- toxication. Further experiments are in progress tides but only when the quartz grains were 3/ or to verify the conclusion of these authors that less in diameter, and they did not develop on in aluminum coats the surface of the quartz particles jecting suspensions of other minerals ground to with insoluble material.* the same size. Recent observations indicate that all species of Mr. Dworski and Mr. Delahant have extended animals are not equally susceptible to Intravenous these early observations in a long series of ex injections of quartz. Dogs, which develop sili periments that have yielded interesting though cotic fibrosis very slowly and under conditions puzzling information. They have shown that fine not yet defined, tolerate intravenous injections of silica injected into the left side of a guinea pig's comparatively large doses of fine quartz without heart acts like a strong poison. symptoms of any kind. . Rabbits, guinea pigs and .Symptoms of shock followed by death within white rats all die of shock. a few minutes to one hour occur when a 400-gram Soluble colloidal silica in dispersed phase is also guinea pig receives an intracardiac injection of 3 0r 4 cc. of a 1 % suspension of 1 to 3/t quartz par ticles in physiological salt solution. The reaction is specific in that it is not produced by quartz par * Subsequent experiment* have shown that sterilizing suspensions of metallic aluminum by heat destroys their power of neutralizing the action of silica. Unheated sus pensions of the metal are just as effective as the hydroxide. Pagt 48 ' * ,*** *. INDUSTRIAL MEDIC . ". f . February, 194g toxic, and intravenous injections produce the re peared to be quite uninfluenced by the ingested actions just described with extremely small doses. material- in the case of particles 3p or under the With larger ones death occurs promptly with number inside each phagocyte was countless, and' symptoms referable to the respiratory tract The there was marked evidence of degeneration of the lesions are then confined to over-distention of cytoplasm of these cells. In other words, the ti- the lungs and subpleural petechial hemorrhages. feet of surface area had to, be exerted inside of the cell and not upon the body fluids as a whole. Ex- 8 THE results produced by injecting particulate tracellular quartz seemed to have little influence,silica into the circulation all suggest a rela and even Intracellular particles of a large sizetionship to a large amount of mineral surface sudproduced no visible evidence of irritation. | denly brought into contact with the blood or tis sues. This is borne out both by the absence of reaction to large particles in excess of 3/< in diam eter and possibly by the observations on neutral ization. Any effect due to preformed soluble THIS observation brings us back to the cause of these progressive changes. Apparently;, they are initiated with degeneration in the pri-*' mary phagocytes, an effect which is exactly paral silica liberated in the suspension before injection leled 'in the histogenesis of tuberculosis. Some! " has been eliminated, and no active soluble silica years ago I published a paper calling attention] : could be demonstrated in the blood of an animal to the similarities between silicosis and tuber- i dying in shock by transfusion into a second host culosis.5 In both of these diseases the primary? Everything now suggests an effect taking place irritants, quartz grains or tubereule bacilli, ax' very rapidly at the interface between the quartz the ease may be, intoxicate the phagocytes.' In] ' and some element in the blood or tissues. Whe tuberculosis the cells thus poisoned are commonlyther this Is due to the very rapid production of designated as "epithelioid cells;" in silicosis the j colloidal silica in this location or to unique elec trical properties of quartz is still a fascinating subject for speculation. In the same category Is the demonstration of the tolerance conferred by morphological effect is similar. Visible fat. ' droplets accumulate in the cytoplasm and the : elements stainable by supravital dyes undergo. . rearrangements in characteristic patterns. Giant- previous injections. The manifestation of scute toxic symptoms by those species of which develop silicotic fibrosis most readily and their absence in the dog, which appears to be much more resistant, sug cells of the Langban's type are produced in each1 disease by stimulation and repeated multiplication: ; of the nucleus. In each disease many cells die: ! and their degenerated products are liberated bt | the tissue spaces. Incidentally it is the pabulum i gests that these immediate reactions may have of necrotic cells in silicotic lesions on which tu- I some bearing on the etiology of silicosis. Until bercle thrive so well, an effect which is responsible : more is learned about the reactions in the dog no for the high frequency of complicating tuber- ; inference is possible. * culous infection in silicotics. In the tubercle it, : The influence of particle size Is just as signifi is in the necrotic or caseous tissue that tubercle- i cant in the production of advanced silicotic fibro bacilli are most frequent. Perhaps they not only- ! sis as it is in eliciting acute symptoms of intoxica cause such caseation but they themselves thrive ! tion. Many injection experiments have convinced on ft Coincidentally more cells migrate to the [ * us that quartz particles over 3? in diameter are area and proliferate to form the granulomatous | of little or no physiological significance. The fact nodule that is characteristic of each disease, t > that the lungs of persons exposed to most dusts Finally the production of necrotic tissue, high : contain few particles larger than 10p1n diameter in lipoids, by two very dissimilar primary 'Ixrt-' has been responsible for the establishment of this tants recalls the experiments of Fallon* and his ' size as the maximum important in dust counting. hypothesis that it is these lipoids which are d j As a matter of fact we know that with some dusts rectly responsible for the formation of the granu-f ' there may be many larger ones. While it would loma. He showed that the injection of such | be just as well that any large fragments should lipoids, freed at least partially of contaminating | be excluded from the lungs, it is felt that only silica particles, was capable of producing a granu-; 1 ones 3p or less in diameter are responsible for lomatous nodule. - | causing silicotic fibrosis. Such mechanisms may be Involved in the pro11 We have long maintained that particles of this duction of both silicotic nodules and tubercles. | size are irritating because they present a suffi It still remains to demonstrate the nature of the I cient surface of silica to the fluids. Recently Mr. primary* injury by each of these irritants, and it-1 Dworskl decided to test this reasoning further by is this problem that will probably engage our at* 1 injecting graded doses of different sized quartz tention for some time to come. _ . particles which would all present the same total surface area. He found, however, that regardless Bibliography*; *; of the total surface, silicotic reaction only de 1. CAAO.vea. L. U.. and Cvmmcws. D.E.,: Studies os veloped when the size of the particles was 3p or Experimental Pneumoconiosis: VI. Inhalation of Asbeste* less. On examining his material it was-discov- ered that with particles 4 to 5|> in diameter or larger there were only two to four visible in a thin section of each phagocyte. These cells ap Dust:. Its Effect upon Primary Tuberculous Infection. I. Indust. Hyp., 13:63-68 and 97-114. February* and March 1931. ' 2. Gahont*. L. U.. and Cvmmi.vcs, D. E.: The Reacttoe to Fine and Medium-Sized Quartz and Aluminum Oxldt | C Vou 9. Nol 2 * INDUSTRIAL MEDICINE i Page 49 Futlctes/ Silicotic Cirrhosis of tho Liver. Am. / Path., tion. This is done with the intent of placing that 1933:9, Supplement whole number 34, 731-763. 3. Timothy Leary: Personal Communication. 4. Denny, J. Jh Robson, W. and Irwin* D. A.: The prevention of Silicosis by Metallic Aluminum. Canad. A.37:1-11, 1937. '3, Gardner, L U.: The Similarity of the Lesions Pro duced by Silica and the Tubercle Bacillus. Am. A Path* individual in industry where he or she is best physically as well as mentally fitted. This exam ination is not done for the purpose of either pass ing or rejecting that person for employment. This pre-employment examination gives the examining physician the best possible opportunity to detect 13:13-23, January, 1937. 6. Fallon; J. Specific Tissue Reaction to Phos pholipids: A Suggested Explanation, for the Similarity of the Lesions of Silicosis and Pulmonary Tuberculosis. Ommf. Af. A. J- 36:223-228,1937. . pulmonary tuberculosis. ' Dr. Robinson'Bosworth, President of the Illinois* Tuberculosis Association, states:* "85% of adult pulmonary tuberculosis has its beginning in the age group 18 to 28. hi the vast majority of cases there are no symptoms and no physical signs." A Plan for the Control of It is exactly this age group that concerns us most in our pre-employment physical examina Tuberculosis in Industry tion, for it is during this age period that most em ployees first enter industry. We therefore feel Max R. Bubneli, MJD, Medical Director, that such an examination is not complete without an x-ray of the chest We believe, with Dr. Andrew R. Riddell, of the AC Spark Plug Division General Motors Corp^ Industrial Hygiene Department, Ontario Depart Flint, Michigan ment of Health, that the wholesale tuberculin testing in industry has many disadvantages. He T IS a proud day when It can be stated that I one of the safest places to be in this country is at work. Statistics from the National Safety states that* "the individuals must present them selves at least three times--there is considerable disruption of work--even after most careful ex Council seem to bear this out. The reduction inplanation as to the meaning of the test, the em the frequency and severity accident rates in our ployees who react positively are greatly dis industrial institutions has been nothing short of turbed." remarkable. Prevention has been the watchword. Applicants in whom active pulmonary tuber With such improvements, the consideration of culosis is discovered are sent to their family physi ie medial departments in industry has more re cian. Our roentgenogram is at his disposal, but cently been drawn to the general health of its em must be returned to our files so that we can later ployees. Attention to the control of tuberculosis compare the progress of the disease and determine has been a very major issue. We believe that in at what future time those persons may be pro no adult group throughout the country can so nounced employable. much be accomplished in prevention and early Applicants with arrested or quiescent tubercu recognition of this disease as in our industrial in losis are placed at work after being informed of stitutions. - their condition and instructed to return for pe legislation varies in the different States regard riodic examinations. These examinations for new ing occupations! disease but the ultimate objective employees, in this classification, are conducted of this legislation is dean The general health of every three months. thp employee must, increasingly become the.re It has been increasingly evident that our- re sponsibility of the employer. While the status of sponsibility does not end there. We explain to tuberculosis has been debated by many legisla the employee that while he now has an arrested tive bodies, silico-tuberculosis is definitely com tuberculosis, it was once active. We encourage pensable. In the state of Illinois the new occupa him to have the members of his family examined tional disease disability compensation law went by the family physieian. We feel that not until into effect on October 1,1936. Dr. C. 0. Sapping- then has industry wholly discharged its duty to - ton states that "during the first year of the oper 'the community. ation of this law, 10.9% of disability claims filed 2. Periodic ExANteranoNs roa Old Employees. were for pulmonary tuberculosis while silicosis These examinations are made at different times claims were 15% of the total."1 and for varied reasons: The corporation that is looking toward the fu (a) Upon returning to work after vacations. ture with the best interests of its employees in (b) After absence caused by an illness. mind certainly should be actively engaged in the (e) Re-employment following seasonal lay-off. problem of the control of tuberculosis. Many of (d) Transfer from one type of work to another. .. our industrial institutions have already shown, by (e) Medical department requesting the exam *marked reduction of the incidence of pulmonary ination for some definite reason. 1" berculosis, just how this can be accomplished. (1) Volunteer requests by the employee for Our own corporation has a very definite program such an examination. concerning tuberculosis. Little comment is necessary concerning these examinations except to state that every employee THE PROGRAM: 1. The Phe - Emtloymext comes into our medical department for a general Physical Examination. Every prospective physical check up at least once each year. employee is given a thorough physical examina Two types of periodic examinations deserve Pag* SO INDUSTRIAL MEDICIX! February, ]g49 special attention. First, the medical department plant safety engineer and 'again adopt ``preven requesting the employee to appear for some spe tion" 85 our slogan. , cific reason. Each employee has his own physical As Dr. C. D. Selby has stated, the industrial record card. His visits to the medical department physician is the health officer of the plant.* "It I* are recorded here. If it is noticed that frequent his duty to locate, identify pnd determine the Im visits are being made for colds, bronchitis, loss of portance of all occupational and environmental weight, feelings of fatigue, etc., he is requested, sources of disease or health impairment and. to. to appear so that we may get at, the underlying see that they are corrected.** , '1 cause. These examinations are always accom In relationship to tuberculosis he must know if[_. panied by x-rays of the chest and if the disability "exposures" to the inhalation of dust particles onS is from early tuberculosis, we are sble to detect it. obnoxious gases and vapors are present within the- " The other type of periodic examination Is most plant Also he-must pay attention to overcrowd^ gratifying to the medical man in industry -- the ing, proper lighting, ventilation, arranging rest: 6 physical check up requested by the employee him periods for those engaged in strenuous or neces?K self. This is, indeed, a measure of the confidence sarily rapid operations, and have knowledge of thd that has been established between the medical de toxicity of materials handled. jl partment and the worker. Dr. Hamilton7 has listed definite Industrial poUtt Cooperation with the family physician is of sons which are capable of irritating severely the paramount importance. When some disability is bronchopulmonary system and activating a pre?js> uncovered and it Is discussed with the employee's existing pulmonary tuberculosis -- chlorine gai k own physician, that employee realizes that the ammonia, benzine, brass fumes, phosgene, nltri&K corporation is not attempting to deprive him of add fumes, selenium and vanadium, to mention >- his job but is trying to keep him at work by im few. proving his health. Again confidence is estab The danger of .exposure to the inhalation of. lished, and that is the best foundation for a suc dust, especially silica dioxide (crystalline sUca)j cessful program to maintain a high standard of is only too well known. It is not within the prcv-- ft health within your organization. ince of this paper to discuss silicosis. However;E One striking example of such a relationship is as Dr. Riddell* has stated. "Tuberculosis is the of unusual interest in regard to the .tuberculosis commonest and most important complication in.* problem. After the installation of excellent x-ray deaths among silicotics. Therefore In any dis-' equipment in one of our plant hospitals, it was cusslon of the control of tuberculosis in industry"! suggested to the employees that they take advan the subject of sflico-tuberculosis must have its! tage of this opportunity to have their chests place." . . i x-rayed. These were all old employees, some Dr. LeRoy Gardner* contendsthat "silicosis is with service records of over 20 years. The re the menace that it is because it specifically pre-' sponse was amazing. Over 4600 employees re- . disposes to tuberculosis. It is the latter which is quested the examination during the first 10 responsible for disability, lost time, and, in many months. cases, death, and it is really tuberculosis against; All of these employees were working every day. which we have to fight" H They considered themselves in excellent health-- This statement has been recently challenged by so did the medical department as a matter of fact, Dr. George Ornstein.'* $ as their previous physical examinations during Whatever the conclusions may be in the future- -the year had -shown -no disabilities. However, 12 concerning (he exact relationship of silicosis to' cases of early active tuberculosis and 42 cases of tuberculosis, the industrial physician must eon? arrested or quiescent tuberculosis were brought tinue his attempt to eliminate dust | to light The active cases are all under treatment Dust counts should be made to locate the points --nine of them have been referred to sanatoria by of greatest hazard. Consultations should be held' the family physician. Active tuberculosis has also with the safety engineer as to the best type of con been found by the family physician in the house trol, whether (a) mechanical ventilation of the ff holds of those in the arrested groups. ' * positive or supply type or local exhaust systems; g . 3. Control or Tuberculosis Within the Plant. (b) Isolation or total enclosure methods, or (c) If there is to be real control of tuberculosis in in respiratory protection by respirators and positive dustry, the activities of the industrial medical de pressure masks or helmets, are to be advised. ; partments must not stop with examinations with Tin the plant hospital. Dr. G. T. Drolet4 has shown conclusively that HE purpose o industry is manufacturing; Often the installation of adequate equipment | where there are bona fide cases of active tubercu is expensive. This adds to the cost of thein'anu* E losis the results of treatment, irrespective of featured article. It behooves the industrial physi where or how, are still far from satisfactory. In cian to study his problem with care. Our experi Other words, "the hopeful sign is steady reduction ence has proved that when management is in in the number of cases and not what happens .10 formed of the hazards that are present and shown those who actually develop the disease. Progress the necessary steps toward their elimination, has come by prevention and not through treat whole-hearted cooperation is immediately forth*; ment."* coming. ** We must take a page from the program of the To Summarize: A plan to control tuberculosis mo . wn-' im- ntal d to nr if a or *the owdrest ecesf the polr the pre gas, iltrlc ion a n of lica) provever, s the m in * r*. J sis is preich is many gainst ed by iiture sis to ; con- points e held if conaf the items; >r (c) ssitive d. uring. pment manu- L shown nation. forth- culosis ^ Vol. 9, No. - ' .. , INDUSTWAL MEDIC*. ` Page St' in industry must start with pre-employment ex amination. The majority of employees firs: enter ' industry during the age period when adult pul monary tuberculosis is most prevalent. X-ray of the chest is a requirement, if early cases are to be detected. When arrested or quiescent cases are discovered, we feel that it is industry's duty to the community to cooperate with the family physician in an attempt to uncover active cases in that em ployee's household. .. Once the employee is at work, periodic ex aminations are the next requirement. Such an examination should be conducted at least annually. The employee quickly learns the per sonal value of these physical check ups. Con fidence then established between the worker and the medical department goes far toward simpUfy- . ing any plan for the control of tuberculosis in in- dustzy. - Lastly, the influence of the industrial medical department must extend to every department of the operating plant. Inspections must be made regularly. The industrial physician should be ; familiar with every possible "exposure" to health impairment. This is the final requirement of our program. . Our goal should be to make the employee's hours at work sot only the safest from accident . but also the freest from exposure to disease. References: ' ICO. Safpington, MD-, DaPJC: Central Stares So ciety.of Industrial Medicine and Surgery. May 17. 1933. 2. Hoaxxftox Boswortk, MD.: University of Michigan Postgraduate Lecture, October. 1938. 3. Andrew R. Riddell, M.D.: Industrial Medicine, Vol. 1 No. S. May, 1939. . 4. O. T. Drolet, MD.: Am. Ket\ Tubere, Feb- 1938. S. James A. Bjottok, MD.: Industrial Medicine, Vol. . 7, No. 8. June, 1938. 8.C. X). Selby, MD.; Paper presented before National Tuberculosis Association, Los Angeles, Juno 23. 1938. * 7. Auct Hamilton. MD.: Industrial Poisons in the ' United States. MacMillan Co. - t Andrew TL'Riddell, 1CD.: Trans. National Tuber culosis Association, 29-1933. 9. LzRoy U. Gardner, MD.: Third Symposium on , Silicosis, 1937. 19. George Ornstezn, MD.: Industrial Medicine, Vol 7. Ho. 7, July, 1938. X-Ray in Industry "M. Wn.LTam Clift, MD., FA.CP_ Hurley Hospital, Flint, Michigan HE new attitude that has grown up between Tindustrial physicians and the employees of this organization, stimulated by the consult* ' ant, has made it not only an interesting privilege but also a pleasure for an associate to be in contact with what we must feel are among the best ideals, of the medical profession. Therefore, it seelhs to me that you might be interested In my experience of the past two years in the field of x-rav in in dustry. " That x-ray has had its definite function you all know, from the several years that industry has recognized its use. The contact of the roentgen ologist with the industrial physician has been largely in the field of forensic medicine. With the new awakening of industry to the importance of preventive medicine has come a.change in the qualifications of the roentgenologist and the physi cian. and a necessity for greater cooperation with and by the management of the organization. This has meant a study of the hazards of industry. That necessitates not only an intimate knowledge of those hazards but of those who. may encounter them. Therefore, the roentgenologist must have a dose contact with the factory physician, who in turn, must have contact with the individual em ployee and be conversant with the nature of his work. Just how large a part the- roentgenologist can contribute to this field of medicine depends upon two factors: first, the physical set-up of the de partment and, second, the cooperation received from the management. The extent of the equipment naturally depends upon the size of the plant and the burden that will be imposed upon the medical department How- ever, there are certain minimum requirements that can not be neglected if efficient service is to be rendered. The equipment and arrangement of the department must be such as will produce the results most economically. In the past two years the author has bad the opportunity to organize and try out, what in his own mind is a model industrial x-ray department, this because of a sympathetic management and- the helpful cooperation of a medical department. which was attuned to the requirements of modem industrial medicine. It is impossible to do adequate work without efficient equipment And it has been thoroughly demonstrated that in larger, factories x-ray work can be done most economically within the plant itself. To refer cases to the private roentgenolo gist is both expensive and lacks the cohesive ef ficiency that can only be obtained within the organization. . The result of two years' experience has demon strated that the .initial cost of the x-ray equipment is an extremely small factor in the economics of a medical department With the most modem equipment and with a well regulated plan of operation the cost per case is hardly an incident in factory medicine. My experience in the or ganization with which I am connected has shown that the entire capital investment for the x-ray equipment has not only been liquidated but has also shown a dividend in less than two years. How ever. the greatest dividend has been in the salvage of individuals working in factories and by appreci ating their physical needs, placing them back in industry in positions they can adequately fulfill. In the time that we have had the opportunity to examine the employees, we have seen upwards of 600G cases. We have detected cases of early tu berculosis. placed .them under the proper condi tions for their rehabilitation, and had the pleasure  /'.* v...';.':': .( * ,.t . THE ' . ^ American Review .. . . - ::. . OF Tuberculosis r . * * -v .. ,* * OFFICIAL JOURNAL OF "" . THE AMERICAN TRUDEAU SOCIETY. , f . . .* '1 . ' . 1 MAX Pinner* New York Qty xarro* npxrrvs . ALUM X. KMVSt, Balthooro, Kai^Uad ' ' unosu* board Joan AiiXAMin, Aon Arbor, Mich. Mvo H. Douglas, Dotrolt, Mich. J, Burns Amurson, Jb, Now YorfcOtj U U, GARDNER, Saranac Lake, N. Y .LJl Baldwin, flinaae Uk N. T. Ross Goldin, Now York Qty H. J. GOWU, Diww, CoU Esmond IL LoNOPhUaCtlphU, Fa. F. 8. Doubt, LwAoliIoi Calif, L, J, Moorman, Oklahoma Clt* ' ' D, W, Richard*, Jil, Now York CUjr VOLUME XLI JANUARY-JUNE, 1940 PUBLISHED MONTHLY SC-ALL-01984 SCF-FA-0725 CLINICAL STUDIES IN ASBESTOSIS1 MOSES J. STONE1 Among the newer diseases, which are a byproduct of our industrial age, asbestosis has come to occupy a fairly prominent position. The diagnosis of this form of pneumonoconiosis, its clinical course, the effect it produces on organs other than the lungs as well as its various compli cations and sequelae are still very much in the controversial stage. The marked development in the industrial use of asbestos has resulted in an increase in the number of people exposed to this occupational hazard. This, together with the greater interest developed by medical men and legislature boards in industrial disease, has produced a great impetus in the study of this subject. The literature on this subject is still rather meagre, and only recently has the hazardous nature of exposure to asbestos dust been recognized and studied. Asbestos is a hydrated magnesium silicate, the composition of which varies with the sections from which it is mined. Most of the asbestos used in the United States is Canadian crysotile containing approximately 43 per cent magnesium, 13 per cent water and traces of iron and nickel. To be sure, asbestos is not a new mineral. Known to the Romans, who mined it from the Alps and from the more remote Urals, the mineral was mentioned in the writing of Herodotus and the second Pliny. Marco Polo spoke of its use by the Tartars. Only within the last decade, has the subject of asbestosis really re ceived the attention of the medical world. Prior to 1924, there is but one recorded case of disease due to the inhalation of asbestos dust. This was recorded in 1900 by Montague Murray in the Charing Cross Hospital Gazette. The first complete description of this disease entity appeared in 1927 when Cooke (1) and McDonald (2) reported 2 cases of asbestosis and discussed the histological changes found in the lung. Hoffman (3) was the first American to focus attention on the magnitude of the asbestosis problem in the United States. In 1930 Mills (4) 1 Presented at a session of the Clinical Section at the 35th annual meeting of the National Tuberculosis Association, Boston, Massachusetts, June 28, 1939. * 520 Beacon Street, Boston, Massachusetts. ' S; * E._ !; X An bodie the a taini] ordin with ment pears asbes to be the f thick and oblit pulir. throi thicl othe: cytei tube lumi amo scatl the bron even fibre saril tissc Si and the to ii tory T mei our industrial osition. The Lrse, the effect irious complid stage. The resulted in an tional hazard, lical men and :at impetus in is still rather exposure to .tion of which f the asbestos pproximately m and nickel. Romans, who , the mineral liny. Marco )sis really re , there is but sbestos dust, haring Cross iisease entity orted 2 cases . in the lung, le magnitude 30 Mills (4) 5 of the National ASBESTOSIS 13 offered the first pathological report published in the United States. In the same year, Lynch and Smith (5) reported their findings on asbestosis bodies. An interesting feature of asbestosis is the finding of the asbestosis bodies in the lung as well as in the sputum. Gloyne and others described the asbestosis body as a core of asbestos fibre surrounded by iron con taining deposits. It is golden yellow in color and does not stain with ordinary histological stains but becomes a brilliant blue when treated with potassium ferrocyanide. The bodies are slender, elongated, seg mented structures with bulbous ends. The substance of the body ap pears homogeneous except for the centre linear thickening which is the asbestos fibre. The essential features of the pathological changes appear to be pleurisy, marked diffuse fibrosis with contraction of the lungs, and the presence of the asbestos fibres and the asbestosis bodies. Uniform thickening of the visceral pleura is found with varying degrees of pleural and pericardial thickening. The fibrosis extends into the apices with obliterating layers of fibrous tissue surrounding the bronchioles. The pulmonary endarteries are surrounded by fibrous tissue and may show thrombosis. The interlobar and intrapleural connective tissue is thickened. Numerous alveoli may be obliterated by fibrous tissue, others may be emphysematous, while still others are filled with leuco cytes and alveolar cells. Occasional giant cells, not to be mistaken for tuberculous giant cells, are found. There are asbestosis bodies in the lumina of the bronchioles, in the alveoli and in the fibrous tissue. An amorphous brown pigment, often phagocytized by the alveolar cells, is scattered throughout the lung. On section the trabeculae stand out in the fibrous network and may present evidence of septic bronchitis, bronchiectasis, bronchopneumonia or lobar pneumonia as the terminal events. Lynch (6) and Gloyne (7, 8) note that the presence of asbestos fibres in the mouth and nose are indicative of exposure but not neces sarily of disease. Essentially the presence of asbestosis bodies indicates tissue response to dust. . Since 1930 mvtA has been written on this subject both from the clinical and public health points of view. Many controversial points, such as the action of asbestos dust on lung tissue, the relationship of asbestosis to infections, especially tuberculosis, and the effect it has on the circula tory system, etc., still remain that demand the attention of investigators. This report is based on a study of 180 patients who were examined by me in collaboration with the late Dr. John B. Hawes, 2nd. (*The patients had been em asbestos brai or weaving r< work of crus been employ more than tv disability da the years of at the time o Of the m daimed disal any abnorma 148 patients * A patient wa chest expansi dence of incr< this interpre difficult to dr Unlike silicon after considei proper histor then not witl Fto. 1. Stage asbestos brake-li strength, also soi Fig. 2. Stage firing asbestos b about the same;; Fig. 3. Stage has marked dysp Unable to lie dot Fig. 4. Asbest ASBESTOSIS IS had been employed for three years or more in a factory manufacturing asbestos brake lining for automobiles and worked in the carding, spinning or weaving rooms. Many of them were engaged in the more dangerous work of crushing the crude asbestos. The great majority of them had been employed from five to fifteen years, and many had worked for more than twenty-five years. The cases came to our attention through disability claims and were given complete physical examinations during the years of 1936 and 1937. None were employed in asbestos factories at the time or since their medical examinations. , CLASSIFICATION Of the 180 patients, 32 were diagnosed as negative, although they claimed disability. X-ray film as well as physical signs failed to show any abnormalities that could be ascribed to asbestosis. The remaining 148 patients were classified as follows: Stage I--78 patients ' Stage II--54 patients Stage HI--16 patients A patient was classified as stage I when there was definite limitation of chest expansion (less than 2 inches) in addition to roentgenological evi dence of increased lung markings. It must be admitted that frequently this interpretation must be somewhat arbitrary, as it is often quite difficult to draw the line between normal and exaggerated lung markings. Unlike silicosis the early fibrotic changes are very indefinite and only after considerable experience, careful standardized X-ray technique and proper history, can a diagnosis of early asbestosis be made, and even then not with any degree of certainty. In stage II were included those Fig. 1. Stage I. Patient worked for four years as an inspector in a plant manufacturing asbestos brake-lining. Two years prior to the examination he noticed lack of energy and strength, also some cough and expectoration. There was only slight dyspnoea on exertion. Fig. 2. Stage H. Patient worked for thirteen years as an inspector in a plant manufac turing asbestos brake-lining. He has had dry cough for seven years which has continued on about the same; also dyspnoea on the slightest exertion. Fig. 3. Stage HI. Patient has been exposed to asbestos dust for twenty-five years. He has marked dyspnoea and has to sit up on a stool at side of bed and sleeps in that position. XJnable to lie down. Chest expansion, one inch. . .* Fig. 4. Asbestosis bodies found in the lungs of patient who died of pulmonary tuberculosis. Note the various sixes and shapes of these bodies, as seen with the low power lens. Fig. 5. Asbestosis body. High power magnification Fig. 6. Another view of the asbestosis bodies (high power) 16 MOSES J. STOKE patients who had definite symptoms and whose X-ray films revealed definite evidence of pulmonary fibrosis. In stage HI were included those patients who had both definite symptoms as well as roentgenologi cal evidence of marked pulmonary involvement. LENGTH 03? EXPOSURE Number of Cow 47 56 40 25 Years qf Exposure 4 or less 4-9 9-14 14 years and over . The chest ing emphys* quite meagi patients. 1 pansion. h! hyperresona disclosed pr dry cracklinj evidence of i RELATIONSHIP OP LENGTH OP EXPOSURE TO PATHOLOGICAL CHANGES IN THE LUNGS Of the 47 patients who were exposed four years or less, 25 showed no definite pathological changes; 14 were classified as stage I and 8 as stage II. Fifty-six patients worked four to nine years. Of these, 36 cases were classified as stage I, 12 were considered as stage II or fairly marked asbestosis and 8 were found to be suffering from advanced or stage HI asbestosis. Of the 40 patients who were exposed ten to fifteen years, 14 were classified as stage I, 20 as stage II and 6 as stage III. Twenty-five patients were exposed for over fifteen years. Of these, 9 showed the early pulmonary changes of stage I, 14 were classified as stage II and 2 as stage m. The average length of exposure of the stage I patients was eight years; stage II, ten years; stage HI, eleven years. While there is but slight evidence that the degree of fibrosis is apt to increase with the length of exposure, there are other factors, such as intercurrent infections and other constitutional factors, that play a part in the development of fibrotic changes in the lung structures. Since all patients were seeking compensation on account of disability, many of the complaints were undoubtedly exaggerated. On careful questioning, however, one could evaluate the symptoms fairly accurately. The outstanding symptom in all the patients was dyspnoea. Many also complained of tightness in the chest. Of the 54 patients in stage II, 32 complained of dyspnoea on slight exertion, tightness in the chest, cough and general fatigue. In addition to the above symptoms-, 10 pa tients also complained of marked loss of weight. AH of the 16 patients in stage EQ complained of dyspnoea, inability for any sustained effort, cough, expectoration, tightness in the chest, anorexia and loss of weight. X-ray exa the diagnosi silicosis will cult. Early ture and she tunity to ex In the ear the lower zo shadows are than the not apparently s the X-ray e\ dicative of sf lung zones, ibentgenosa angle is obli fibrosis of i parenchyma granular or' the usual lie the midlung creased and cases in our because of t parenchyma tns revealed ;re included entgenologi- . CHANGES IN 25 showed no a I and 8 as Of these, 36 je II or fairly . advanced or . ten to fifteen as stage HI. . Of these, 9 e classified as re of the stage , eleven years, rosis is apt to xtors, such as lat play a part Lires. it of disability, d. On careful irly accurately. ;a. Many also its in stage II, s in the chest, mptoms, 10 pathe 16 patients iustained effort, i loss of weight. ASBESTOSIS 17 PHYSICAL EXAMINATION The chest findings were mainly those of basal fibrosis with accompany ing emphysema at the apices. On the whole, physical findings were quite meagre, and were not in proportion to the symptoms given by patients. The outstanding physical sign was diminution of chest ex pansion. Many cases showed evidence of dulness at the bases with hyperresonance near the apices. In the majority of cases auscultation disclosed prolongation of the expiratory phase with some high-pitched dry crackling rides. Moist riles were found only when there was definite evidence of associated bronchitis or bronchiectasis. X-BAY EXAMINATION X-ray examination constitutes the most important single procedure in the diagnosis of asbestosis. Those who have examined many cases of silicosis will find the X-ray interpretation of asbestosis extremely diffi cult. Early X-ray diagnosis of asbestosis is still in the realm of conjec ture and should be undertaken only by those who have had the oppor tunity to examine many such cases. In the early stages there is only a slight relative increase in density in the lower zones producing a filmy, hazy appearance of the bases. The shadows are much finer, lighter, and have a granular appearance, rather than the nodular or patchy type of infiltration found in silicosis. The apparently small amount of lupg involvement in the early stages makes the X-ray evaluation rather difficult. As the disease progresses, signs in dicative of stage II are seen. There is an increase in density in the lower lung zones, the diaphragm becomes indistinct in outline and shows, on roentgenoscopic examination, limitation of motion. The costophrenid angle is obliterated by thickened pleura. A fine lace-like network of fibrosis of interstitial or perivascular form rather than a definitely parenchymatous type is seen. x The characteristic chest X-ray film shows granular or "ground-glass'Nippearance with more or less obliteration of the usual linear pulmonic markings. This is localized iiujnost cases in the midlung region and bases. The bronchovascular markings are in creased and often pericardial and pleural thickenings are noted. Many cases in our series showed elevation of the diaphragm. In stage HI, because of the frequently associated bronchitis and bronchiectasis, the parenchymatous change^becomfe more marked. 18 MOSES J. STONE TUBERCULOSIS IN ASBESTOS WORKERS The still debatable question of the relationship between asbestosis and tuberculosis has been discussed by numerous authors. This study was mainly undertaken to determine the incidence of tuberculosis among asbestosis workers. Since many patients do develop pulmonary fibrosis, their resistance to pulmonary infections is greatly decreased. Most of the English investigators, among them Stewart (9), found marked in crease of tuberculosis infection among asbestos workers. He states that there can be no question that pulmonary asbestosis predisposes to tuberculous infection of the lungs. His opinion is also held by Ellman (10) who found an increasing incidence of tuberculosis in persons exposed to asbestos dust. Donnelly (11) refutes these above statements and finds no definite relationship between asbestosis and tuberculosis. In fact Merewether and Price (12), finding only 3 cases of tuberculosis among 374 cases of asbestosis, indicated thaf a lessened susceptibility to tuberculosis existed in such cases. Out of 180 films taken in our series of cases, 9 showed evidence of parenchymatous tuberculous infection; two of this group had active tuberculosis and 7 showed inactive or healed lesions. In our series of 16 cases of advanced asbestosis, only one had active tuberculosis. One other active case of tuberculosis had only moderate asbestosis (stage II). Of those patients who had inactive disease, 5 had moderately advanced asbestosis (stage II), and all had been exposed to asbestos dust for more than ten years. Thus we are not impressed with tuberculosis as being a serious complication of asbestosis. We find that bronchitis, bronchiec tasis and bronchopneumonia are more frequently associated with asbes tosis than is tuberculosis. Indeed we feel that, because of the frequency of tuberculosis in silicosis, many patients with bronchitis or low grade bronchopneumonia were erroneously diagnosed as being tuberculous. Only one person in our total series has subsequently developed active pulmonary tuberculosis, HEART STUDIES * One hundred and fifty patients were studied to ascertain the-cardiac involvement, if any, in cases of asbestosis. Heart measurements were done by Dr. George Levene of the Massachusetts Memorial Hospitals. Ninety of the 150 patients studied, or 60 per cent, showed prominent pulmonary vessels. This prominence was apparently either due to en gorgement < creased in 5i disease, sue disease. T1 the increase cases, or 8 p study was t classified as asbestosis. the pulmon; transverse d of associate* cent, the eu asbestosis. Apparent] tosi$ much j cardiac outL of the lung cardium, th< become thic blurred. T and III may roentgenoset alone will nc cases lateral mended to < any stage o accentuated genoscopic i the heart sb special impc nntral stenc cardiac emt early sympt disease is of We had a two to three asbestosis and .Tus study was culosis among lonary fibrosis, ised. Most of nd marked inHe states that predisposes to aeld by Ellman persons exposed statements and lberculosis. In of tuberculosis susceptibility to 'i h | * f | | | | ? | ( . !y wed evidence of *oup had active In our series of beTculosis. One stasis (stage II). irately advanced tos dust for more irculosis as being chitis, bronchiecdated with asbesi of the frequency litis or low grade eing tuberculous, developed active _ f f; * .ertain the cardiac leasurements were emorial Hospitals, showed prominent f either due to en- ASBESfOSiS gorgement or perivascular fibrosis. The transverse diameter was in creased in 50 cases, or 33 per cent, after excluding cases of organic heart disease, such as hypertension, coronary sclerosis and rheumatic heart disease. Thus it was felt that asbestosis was apparently the cause of the increased transverse diameter in 33 per cent of our cases. Thirteen cases, or 8 per cent of our total series, had right-sided hypertrophy. A study was then carried out to determine the heart findings in 56 cases classified as moderately advanced (st^ge II) and advanced (stage HI) asbestosis. Of these 56 cases, 35, or 62 per cent, showed prominence of the pulmonary vessels; 25, or 44 per cent, showed an increase of the transverse diameter (7 cases of the latter group were excluded because of associated heart disease). In the remaining 18 patients, or 32 per cent, the enlargement of the transverse diameter was associated with asbestosis. . Apparently then the heart and the pericardium are affected in asbes tosis much more so than in any other type of pneumonoconiosis. The cardiac outline is obscured by the superimposed increased fibrous tissue of the lung with advancing degrees of asbestosis. The pleuroperi- cardium, the pleura of the lower lung fields and the diaphragmatic domes become thickened and the usually sharply demarcated heart contours are blurred. The marked emphysema and pulmonary fibrosis of stages II and IQ may cause rotation or lateral displacement of the heart. Unless roentgenoscopic examination is carried out, the sagittal roentgenograms alone will not convey a true impression of cardiac size or shape. In such cases lateral views together with roentgenoscopic examination are recom mended to clarify the diagnosis. The roentgenographic appearance of any stage of asbestosis associated with heart disease may be greatly accentuated by passive congestion. As a result of our studies, roent- genoscopic examination is recommended to determine enlargement of the heart shadow and alterations in the cardiac silhouette. This is of special importance in cases of asbestosis associated with hypertension, mitral stenosis and cor pulmonale. - It is our belief, therefore, that cardiac embarrassment is of utniost importance in the causation of early symptoms. It is evident that the dyspnoea noted early in this disease is of cardiac or circulatory rather than of pulmonary origin. XOIAOW-TJP STUDIES We had an opportunity to reexamine 13 patients of this group from two to three years after their first examination. Two of this group were .if'!! 20 MOSES J. STONE originally^classified as stage IQ; 8, as stage II, and 3, as stage I. These patients were carefully studied in The Clinic for Cardiac Research of the Massachusetts Memorial Hospitals by Drs. George Levene, William Duncan Reid and Maurice A. Lesser. The vital capacity was affected in all cases, being from 50 to 75 per cent below the normal, calculated on the basis of height and weight. X-ray examination revealed definite progression of fibrosis in the two cases that were originally classified as stage HI. Two patients had evidence of old coronary disease. This was corroborated both by the X-ray as well as electrocardiographic* examination. The electrocardiograms of the remaining patients were entirely normal. Sedimentation rates were normal with the exception of the two with coronary disease which showed an increased rate. Our impression gained from the study of this small group is that in advanced fibrosis due to asbestosis the' disease will progress even after exposure ceases. This, however, is not the case in the earlier stages. We also feel that the heart is not' affected unless pulmonary fibrosis is marked. In the light of the blood studies, fibrosis is the result of irrita tion due to asbestos fibres, and is not the result of infection. Since the entire group was first examined, 18 patients have died. The cause of death was given as follows: Pulmonary tuberculosis...........................................................................................3 case9 Bronchopneumonia......................:...................................................................... S cases Lobar pneumonia..................................................................................................... 2 cases Cardnoma...................................... 2 cases Cardiac disease......................................................................................................... 2 cases Cerebral shock........................................:............................................................. 1 case Accidental............................................................................................................... 2 cases Brain tumor.................................................. .................. ............... ........... lease . Most of the patients are still able to pursue a gainful occupation although unable to perform duties that demand much physical exertion. Seven teen patients are semi-invalids, most of them complaining of cough and marked dyspnoea. CONCLUSIONS 1. Asbestosis, like silicosis, constitutes an occupational hazard, arising from exposure to asbestos dust. , 2. Pathological findings are those of pulmonary fibrosis and thickened pleura, most marked at both bases. 3. Dyspnoea is an early symptom and is the chief cause of early disability. 4. X-ray asbestosis X at the bases 5. Broncl plications. 6. Tuberc 7. Advan* hypertrophy 8. When < of involvenn 9. All hea forced in all 10. Work* to asbestos ( I am deeply i Clinic for Cardi Miller of the De me in preparatit (1) Cooke, W.. (2) McDonald (3) HomtAN, 1 U. S. (4) Mnxs, R. S (5) Lynch, K.. 1930, (6) Lynch, K. 1 (7) Gloyne,S. de, 1! (8) Gloyne, S. asbesi (9) Stewaet, h (10) Ellhan, P. (11) Donnelly, (12) Mereweth: tage I. Thes ac Research of ^evene, William ty was affected mal, calculated evealed definite illy classified as r disease. This jocardiographic' g patients were h the exception ised rate, group is that in gress even after te earlier stages, onary fibrosis is e result of irrita- uon. have died. The .............. 3 cases .......... 5cases .............. 2 cases .............. 2 cases ............. 2 cases ............ 1 case . .........2cases ................ 1 case - zupation although exertion, Sevenling of cough and ; i ' j. : (; ;V i " ;^ ^ 0^ ; ' s' Xk <L L > ial hazard, arising osis and thickened ief cause of early ASBESTOSIS 21 4. X-ray findings are not characteristic in early stages. In advanced asbestosis X-ray reveals lace-like interstitial fibrosis and thickened pleura at the bases giving the "ground-glass" appearance. 5. Bronchial and bronchopulmonary infections are common com plications. 6. Tuberculosis is not a frequent concomitant of asbestosis. 7. Advanced asbestosis not infrequently leads to right ventricular hypertrophy and failure. 8. When exposure ceases, fibrosis does not progress unless the degree of involvement is already marked, q 9. All health laws relating to dusty occupations should be rigidly enforced in all asbestos factories. 10. Workers developing pulmonary fibrosis in the course of exposure to asbestos dust should be entitled to compensation. I am deeply indebted to Dis. George Levene, William D. Reid, Maurice A. lesser of the Clinic for Cardiac Research of the MassachusettsMemorial Hospitals and to Dr. Lois C. Miller of the Department of Radiology for their cooperation and valuable assistancegiven me in preparation of this paper. REFERENCES (1) Cooke, W..E.: Pulmonary asbestosis, Brit. M. J., 1927,2,1024. (2) McDonald, S.: Histology of pulmonary asbestosis, Ibid., 1927, 2, 1025. (3) Hoytman, F.L.: Mortality from respiratory diseases in dusty trades, (Inorganic Dusts), XT. S. Bur. Lab. Stat. Bull. 231,1918. 1 (4) Mills, R. S.: Pulmonary asbestosis, Report of a case, Minnesota Med. J., 1930,13,495. (5) Lynch, K. M., and Smith, W. A.: Asbestosis bodies m sputum and lung, J. A. M. A., 1930, PS, 659. (6) Lynch, K. M.: Pulmonary asbestosis, Ibid., 1936,109,1974. (7) Gloyne, S. R.: The presence of asbestos fibre in the lesions of asbestos workers, Tuber cle, 1929,10,404. (8) Gloyne, S. R.: Reaction of tissues to asbestos fibre, with reference to pulmonary asbestosis, Ibid., 1930,11,151. (9) Stewaet, M. J.: Liverpool Med.-Chii. J., 1933,41, part 2,142. (10) Elucan, P.: J. Indust. Hyg., 1933,15,165. (11) Donnelly, J.: Ibid., 1936,18,222. (12) Meeewethek and Puce: H. M. Stationery Office, London, 1930. tlii* mg*xin* it publl*bd to promoto sound thought upon and concoming Industrial modicino and traumatic surgary. To that and it witl contain artklas, naws Hams, rports, digasts, and othar prasantations, togathar with aditore* commants, Tha adHoriaf pol icy U to aneouraga frank discussion. On this basis contributions ara invHad. Tha adttors will asarcka era in check ing on tha accuracy of data printad, but in all othar raipacts articlas and opinions of which aapraislon Is allowed ara tha opinions of thair authors--tha editors raiarring In all casts tha right to comment on the same, in the cur rant or any subsequent Issues, as they may ha ificiinad. The Journal of Occupational Diseases and Traumatic Surgery With which art consolidated /rTh Industrial Doctor" and "International journal of Medicine.and Surgery." The Science, the Law and the Economics of Industrial Health Volume 9 FEBRUARY, 1940 Number 2 General Motors Corporation Medical Conference --Dayton} Ohio, November 2 and St 1939-- HE recent Medical Conference of General TMotors Physicians, held at the Biltmore Hotel,. Dayton, Ohio, November 2 and 391939, comprised five meetings and 18 presentations. The Program was as follows; Thursday, November 2: MORNING Session: Chairman, M. M. Shafer, MD., Medical Director, Frigidaire Division, Dayton. X. "Recent Developments in Relation to Silicosis," LeRoy U. Gardner, MD.( Saranac Lake, New York. 2. "A Plan for the Control of Tuberculosis in Industry," MAx Burnell, MD., Medical Director, AC Spark Plug Division, Flint, Michigan. 3. "X-Ray in Industry," M. William Clift, MD., Hurley Hospital, Flint, Michigan. 4. ``Preliminary Report on Hygiene Studies of Weld ing," L. B. Case and V. J. Castrop, Industrial Hygiene Laboratory, General Motors, Detroit AFTERNOON Session: Chairman, A. L. Brooks, MD., aa Medical Director Fisher Body Division, Detroit 5. "Recent Developments in the Occupational Derma toses," Marion B. Sulzberger, MD., New York City. 6. "The Course of Disabling Morbidity among Indus trial Workers, 1921-1938," William M. Gatater, D.Scm U. S. Public Health Service, Washington, D. G 7. "The Industrial Nurse," Harold M. James, MD., Medical Director, Delco Products Division, Dayton. 8. "The Doctor's Part in the Personnel Program," George A. Coburn, Personnel Director, Delco-Remy Divi sion, Anderson, Indiana. EVENING Session: Chairman, Walter M. Simpson, M. D., Director, Kettering Institute for Medical Re search, The Miami Valley Hospital, Dayton. 9. "Relationships of Industrial Medicine to Private Practice," Stanley J. Seegsr, MD., Chairman Council on Industrial Health, American Medical Association. 10. "Unfinished Business," C. F. Kettering, Director General Motors Research Laboratories, Detroit Friday, November 3: MORNING Session: Chairman, G. L. Bird, MD., Medi cal Director General Motors of Canada, Ltd., Oshawa, Ontario, Canada. 11. "A Practical Approach to Supervision of Mental Health in Industry," F. S. Farney, MD., Chief, Division of Industrial Hygiene, Dept, of Pensions and National Health, Ottawa, Ontario, Canada. 12."An Example of Industry's Participation in the Anti-Syphilis Campaign," P. J. Ochsnkr, MD., Medical Director, Fisher Body Lansing Division, Lansing, Michi gan. 13. "Study of the Factors of Employability, Especially Disabilities and Infirmities of the Elderly, and Problems Arising from Employment of the Same," George A. Paul, MD., Medical Director, Hyatt Bearings Division, Harrison, New Jersey, 14. "Early Diagnosis of Acute Appendicitis," C. Rush McAdam, MD., Medical Director, Fisher Body St Louis Division, St Louis, Missouri. AFTERNOON Session: Chairman, F. B. Wzshard, MD., a* Medical Director, Delco-Remy Division, Anderson, TnAInna. 13. "Relationship of the Length of the Inguinal Liga ment to the Occurrence of Inguinal Hernia," C. M. Hillzhbrand, MD,, Medical Director, Harrison Radiator Divi sion, Lockport, New York. 18. "Hernia in Industry; Review of the Cases During the Past Ten Years," R. t*. Johnston, MD., Medical Director, Inland Mfg. Division, Dayton. 17. "Antiseptics and Their Action," R. M. Freeman, MD., Medical Director, Linden Division, Linden, New Jersey. 18. "Management of Fractures of the Spine," R. W. Poborsky, MD., Medical Director, Electro-Motive Divi sion, La Grange, Illinois. Except for Dr. Sulzberger's address on "Recent Developments in the Occupational Dermatoses" all of the papers given at this Conference are in cluded here in full text, in the order of their places on the Program; Recent Developments in Relation to Silicosis LeRoy U. Gardner. MD., Director, The Saranac Laboratory for the Study of Tuberculosis, Saranac Lake, New York HEN your Chairman asked me to speak of Wnew developments in the field of silicosis I was perplexed because all but a few of the pathological, clinical and diagnostic aspects of this disease are now well established. I realized SC-ALL-02161 SCF-FA-0735 Page 46 INDUSTRIAL MEDICINE February, 1940 that you had become better acquainted than I with in the bronchioles. As collagen forms and con the practical problems of diagnosis because you tracts, the air spaces are obliterated by scar tis were dealing with them every day. After some sue. In experimental animals, at least, this change deliberation I decided to tell you of some of the is not a progressive one after cessation of exposure experimental work in progress at the Saranac to the dust as is the case in the response to quartz. Laboratory and to permit myself to speculate as Perhaps the reason is the deposition of the pe to its significance. These experiments are incom culiar iron-containing coating on the surface of plete and no conclusions -are possible now, but the inhaled fibres giving rise to the characteristic perhaps they may ultimately lead to a better un "asbestosis bodies." Dr. Timothy Leary consid derstanding of the action of irritant dusts upon ers3 that the resultant smooth rounded ends of the lungs. these bodies are no longer capable of scratching As far as I have been able to discover, it is still the delicate surfaces of the air spaces. true that only certain forms of free silica and the Finally it is most suggestive that among dozens group of fibrous silicates known as asbestos, are of different silicate minerals only the five known capable of producing fibrosis in a normal lung. as asbestos, which are unique because they are Many other silicates have been incriminated by fibrous in structure, should be commonly recog roentgenologists, but when autopsy specimens nized. as pulmonary irritants. The variation in have been examined it is discovered that there chemical composition within this group is greater is associated chronic infection or that the inhaled than that between them and many other silicates. dust contains significant quantities of free silica. In fact chrysotile asbestos has the same chemical I shall first compare the action of chrysotile as formula as a non-fibrous silicate, serpentine, bestos with that of quartz upon experimental ani which is physiologically inert. Obviously irrita mals and review considerable evidence bearing tion would seem to be associated with the physical, on their respective modes of action. A few of rather than the chemical, composition of these these observations now have oractical significance; minerals. others may prove to be quite unrelated to the One point of practical significance may be indi pneumoconioses found in human beings. cated by these observations, namely, that very finely ground asbestos is not dangerous. This FOR the last year or two we have been coming conclusion has support in clinical observation, for, to the conclusion .that, inhaled asbestos fibres it has long been known that at the Thetford' mills are irritating not because they are silicates but bethere was no clinical asbestosis even though in cause they are stiff fibres which mechanically ir former years the atmosphere was very dusty and ritate the lungs. Unlike the free silicas, these the dust was extremely fine. The fact that fabri minerals will not stimulate fibroblasts in any part cation of fibres of the same mineral in American of the body; only those in the lungs are affected. plants could produce disease was one of the puz It was inferred that these organs were affected zling features of this disease. But these experi because the movements of respiration are so much ments offer a plausible explanation. The fine dust more rapid and continuous than those of other in the mills is composed of serpentine and ex viscera. Then it was discovered that if asbestos tremely short chrysotile fibres; that in the spin was ground very finely so that few of the fibres ning and weaving mills contains many more long were longer than 2p in length the irritating prop fibres. erty of the asbestos was practically destroyed. In Ihalation experiments with such fine chrysotile asbestos have now been continued for three years. N THE case of free silica everything points to a chemical form of irritation although the solu No fibrosis has developed in spite of the fact that bility hypothesis as now conceived is not com an average atmospheric concentration of 125 mil patible with all the observations that have been lion particles per cubic foot of air has been main made. In experimental animals inhaling or in tained. In contrast I would point out that in a jected with excessive quantities of pure quartz previously reported experiment1 one third this or flint in exceedingly fine state of subdivision, it concentration of long fibre asbestos dust produced can be observed that tissue reaction takes place well marked fibrosis after about two years. in two stages. First there is an acute inflamma If the effect of asbestos were chemical, one tion resulting in necrosis. Following it there is would expect that a decrease in size would ac healing with fibrosis in the form of a granuloma celerate tissue response. With free silica large whose end product is the silicotic nodule. The particles have little effect, but as their size de collagen laid down by the connective tissue cells creases cellular reaction becomes more vigorous is modified in a peculiar way analagous to that in and even constitutional symptoms may ensue.3 the tanning of leather, and this is responsible for With fibrous asbestos the reverse is true. the characteristic hyalinization of silicotic fibro The histology of early asbestosis does not sug sis. Incidentally, leather has been tanned with gest a chemical injury. Even under the most ex silica and sections of such leather reveal that the treme conditions that can be created by artificial collagen has undergone a similar hyaline trans injection there is no preliminary phase of tissue formation. In human subjects only cases of rapid necrosis with infiltration of leucocytes as occurs ly developing silicosis show evidence of a two- with high concentrations of very fine quartz. The stage reaction. In those with ordinary chronic connective tissue cells merely multiply very slow disease, degenerative changes are slight and over ly in areas where the asbestos fibres are caught shadowed by the formation of connective tissue. Vol. 9, No. 2 INDUSTRIAL MEDICINE Page 47 The solubility hypothesis is based solely upon tides of larger size and it has not been observed indirect evidence. It is known that colloidal silica on injecting suspensions of several other minerals is toxic and that quartz will dissolve to some ex ground to the same particle size. tent in slightly alkaline fluids of the same pH as Symptoms are initiated even before completing those of the body. But it has never been possi the injection by the onset of rapid, labored respir ble to prove that silica has dissolved within the ation. The skin of the face and extremities becomes body, because the soluble material is immediately pale. The animal displays uncoordinated mus combined with local tissue elements. It is now cular movements and sporadic convulsions ter generally accepted that the soluble silica detected minating in death if the dose is sufficient. When in the urine and blood probably comes from in smaller doses are administered complete recovery gested food tmd drink rather than from inhaled takes place. dust. Autopsy of fatal cases discloses an intense en gorgement of the spleen, omentum and subperi- WE have made a good many experiments whose toneal tissues which are deep purple-red in color. results are difficult to reconcile with the solu The liver, and in fact practically all the remainder bility hypothesis. They do not necessarily invaolfithe body, is almost bloodless. Counts of ear- date it because we may not have all the facts and do not know how to interpret them. For example, we have found that cellular reactions begin within IS to 30 minutes after injecting fine particulate silica. In the test-tube traces of dissolved silica are only discoverable by an exceedingly sensitive colorimetric reaction after 12 to 24 hours. Possi bly "vital'* factors may accelerate the process, but no means of evaluating them has yet been dis covered. No one has ever produced fibrosis by single or repeated injections of the various forms of soluble silica. The effect is apparently not due to the quantity of silica dissolved, for many of the inert silicates in vitro are more soluble than quartz or flint. Evidences of alteration of the surface of quartz particles long in contact with living tis vein blood show only about half the number of leucocytes present just before the injection and a corresponding reduction in red blood cells. The blood no longer clots. There is no hemolysis. Animals that have recovered from one reaction seem to acquire a tolerance so that in some in stances at least twice the former dose may be in jected without symptoms. The degree of toler ance, however, varies widely in different indi viduals. These symptoms are not influenced by the in jection of adrenalin. They are not reproduced by transfusing the blood of an animal dying in shock into another one of the same species. They are only exhibited on injecting suspensions of quartz particles less than 3/i in diameter. They sue have thus far escaped detection. are not produced by injecting the supernatant In years of experimenting to discover the salt solution from which the quartz particles have mechanisms by which free silica exerts its pe culiar effects upon living tissues we have re peatedly observed evidences of a specific toxicity. Guinea pigs, injected intraperitoneally with large doses of fine quartz particles are often obviously sick for some hours. When Mr. Cummings and been removed by centrifugation. The severity of the reaction does not vary with the age of the par ticle suspension, although the amount of soluble silica increases on standing. The toxic effects of quartz can be more or less effectively neutralized by adding small amounts Mr. Redlin* were seeking an avenue for the of different substances. Colloidal aluminum hy quantitative introduction of silica they tried in travenous injections into rabbits and discovered the method which we now use as a standard for comparing reactions to different dusts. But in cidentally they found that these animals would die very promptly if the unit dose of quartz par droxide gives complete protection in a dilution of 0.03%; colloidal ferric hydroxide is much less effective. Animal charcoal cannot be injected, be cause it flocculates with the quartz and produces emboli. The finely ground metallic aluminum, used by Denny, Robson and Irwin4 in the preven ticles were too large. These deaths were not em tion of silicosis has no influence upon acute in bolic because they did not occur with large par toxication. Further experiments are in progress ticles but only when the quartz grains were 3p or to verify the conclusion of these authors that less in diameter, and they did not develop on in aluminum coats the surface of the quartz particles jecting suspensions of other minerals ground to with insoluble material.* the same size. . Recent observations indicate that all species of Mr. Dworski and Mr. Delahant have extended animals are not equally susceptible to intravenous these early observations in a long series of ex periments that have yielded interesting though puzzling information. They have shown that fine silica injected into the left side of a guinea pig's heart acts like a strong poison. Symptoms of shock followed by death within a few minutes to one hour occur when a 400-gram injections of quartz. Dogs, which develop sili cotic fibrosis very slowly and under conditions not yet defined, tolerate intravenous injections of comparatively large doses of fine quartz without symptoms of any kind. Rabbits, guinea pigs and white rats all die of shock. Soluble colloidal silica in dispersed phase is also guinea pig receives an intracardiac injection of 3 or 4 cc. of a 1% suspension of 1 to 3/* quartz par ticles in physiological salt solution. The reaction is specific in that it is not nmHiwod v.-. 1------ * Subsequent experiments have shown that sterilizing suspensions of metallic aluminum by heat destroys their power of neutralizing the action of silica. Page 48 INDUSTRIAL MEDICINE February, 1940 toxic, and intravenous injections produce the re* peared to be quite uninfluenced by the ingested actions just described with extremely small doses. material. In the case of particles 3/i or under the With larger ones death occurs promptly with number inside each phagocyte was countless, and symptoms referable to the respiratory tract. The there was marked evidence of degeneration of the lesions are then confined to over-distention of cytoplasm of these cells. In other words, the ef the lungs and subpleural petechial hemorrhages. fect of surface area had to be exerted inside of the cell and not upon the body fluids as a whole. Ex THE results produced by injecting particulate tracellular quartz seemed to have little influence, silica into the circulation all suggest a rela and even intracellular particles of a large size tionship to a large amount of mineral surface sudproduced no visible evidence of irritation. denly brought into contact with the blood or tis sues. This is borne out both by the absence of reaction to large particles in excess of 3/i in diam eter and possibly by the observations on neutral ization. Any effect due to preformed soluble silica liberated in the suspension before injection THIS observation brings us back to the cause of these progressive changes. Apparently they are initiated with degeneration in the pri mary phagocytes, an effect which is exactly paral leled in the histogenesis of tuberculosis. Some has been eliminated, and no active soluble silica years ago I published a paper calling attention could be demonstrated in the blood of an animal to the similarities between silicosis and tuber dying in shock by transfusion into a second host. culosis.8 In both of these diseases the primary Everything now suggests an effect taking place irritants, quartz grains or tubercule bacilli, as very rapidly at the interface between the quartz the case may be, intoxicate the phagocytes. In and some element in the blood or tissues. Whe . tuberculosis the cells thus poisoned are commonly ther this is due to the very rapid production of designated as "epithelioid cells;" in silicosis the colloidal silica in this location or to unique elec morphological effect is similar. Visible fat trical properties of quartz is still a fascinating droplets accumulate in the cytoplasm and the subject for speculation. In the same category is elements stainable by supravital dyes undergo the demonstration of the tolerance conferred by rearrangements in characteristic patterns. Giant previous injections. cells of the Langhan's type are produced in each The manifestation of acute toxic symptoms by disease by stimulation and repeated multiplication those species of animals which develop silicotic of the nucleus. In each disease many cells die fibrosis most readily and their absence in the dog, and their degenerated products are liberated in which appears to be much more resistant, sug the tissue spaces. Incidentally it is the pabulum gests that these immediate reactions may have of necrotic cells in silicotic lesions on which tu some bearing on the etiology of silicosis. Until bercle thrive so well, an effect which is responsible more is learned about the reactions in the dog no for the high frequency of complicating tuber inference is possible. culous infection in silicotlcs. In the tubercle it i I: The influence of particle size is just as signifi is in the necrotic or caseous tissue that tubercle cant in the production of advanced silicotic fibro bacilli are most frequent. Perhaps they not only sis as it is in eliciting acute symptoms of intoxica cause such caseation but they themselves thrive tion. Many injection experiments have convinced on it. Coincidentally more cells migrate to the us that quartz particles over 3/* in diameter are area and proliferate to form the granulomatous of little or no physiological significance. The fact nodule that is characteristic of each disease. l that the lungs of persons exposed to most dusts Finally the production of necrotic tissue, high contain few particles larger than 10/t in diameter in lipoids, by two very dissimilar primary irri has been responsible for the establishment of this tants recalls the experiments of Fallon6 and his size as the maximum important in dust counting. hypothesis that it is these lipoids which are di As a matter of fact we know that with some dusts rectly responsible for the formation of the granu there may be many larger ones. While it would loma. He showed that the injection of such be just as well that any large fragments should lipoids, freed at least partially of contaminating be excluded from the lungs, it is felt that only silica particles, was capable of producing a granu ones 3ft or less in diameter are responsible for lomatous nodule. causing silicotic fibrosis. Such mechanisms may be involved in the pro We have long maintained that particles of this duction of both silicotic nodules and tubercles. size are irritating because they present a suffi It still remains to demonstrate the nature of the cient surface of silica to the fluids. Recently Mr. primary injury by each of these irritants, and it Dworski decided to test this reasoning further by is this problem that will probably engage our at injecting graded doses of different sized quartz tention for some time to come. 4 particles which would all present the same total surface area. He found, however, that regardless Bibliography; of the total surface, silicotic reaction only de 1. Gardner, L. U., and Cummings, Oil.,: Studies on veloped when the size of the particles was 3/i or Experimental Pneumoconiosis: VI. Inhalation of Asbestos less. On examining his material it was discov ered that with particles 4 to 5p in diameter or larger there were only two to four visible in a thin section of each phagocyte. These cells ap Dust: Its Effect upon Primary Tuberculous Infection. J. Indust. Hyg., 13:65-68 and 97-114, February and March, 1931. 2. Gardner, L. U., and Cummings, D. E.: The Reaction to Fine and Medium-Sized Quartz and Aluminum Oxide i 1 Vol. 9t No. 2 INDUSTRIAL MEDICINE Page 49 Particles. Silicotic Cirrhosis of the Liver. Am. J. Path., 1933:9, Supplement whole number 54, 751-703. . 3. Timothy Leary; Personal Communication. 4. Denny, J. J., Hobson, W. D., and Irwin, D. A.: The Prevention of Silicosis by Metallic Aluminum, Canad. AT. A. J- 37:1-11, 1937. 5. Gardner, L. U.: The Similarity of the Lesions Pro duced by Silica and the Tubercle Bacillus. Am. J. Path., 13:13-23, January, 1937. 6. Fallon, J. T.: Specific Tissue Reaction to Phos pholipids: A Suggested Explanation for the Similarity of the Lesions of Silicosis and Pulmonary Tuberculosis. Canad. M. A. J,, 36:223-228, 1937. tion. This is done with the intent of placing that individual in industry where he or she is best physically as well as mentally fitted. This exam ination is not done for the purpose of either pass ing or rejecting that person for employment. This pre-employment examination gives the examining physician the best possible opportunity to detect pulmonary tuberculosis. Dr. Robinson Bosworth, President of the Illinois Tuberculosis Association, states:3 "85% of adult pulmonary tuberculosis has its beginning in the age group 18 to 28. In the vast majority of cases there are no symptoms and no physical signs." A Plan for the Control of It is exactly this age group that concerns us most in our pre-employment physical examina Tuberculosis in Industry tion, for it is during this age period that most em ployees first enter industry. We therefore feel Max R. Burnell, MI)., Medical Director, that such an examination is not complete without an x-ray of the chest. We believe, with Dr. Andrew R. Riddell, of the AC Spark Plug Division, General Motors Corp., Industrial Hygiene Department, Ontario Depart Flint, Michigan ment of Health, that the wholesale tuberculin testing in industry has many disadvantages. He T IS a proud day when it can be stated that I one 'of the safest places to be in this country is at work. Statistics from the National Safety states that* "the individuals must present them selves at least three times--there is considerable disruption of work--even after most careful ex Council seem to bear this out The reduction inplanation as to the meaning of the test, the em the frequency and severity accident rates in our ployees who react positively are greatly dis industrial institutions has been nothing short of turbed." remarkable. Prevention has been the watchword. Applicants in whom active pulmonary tuber With such improvements, the consideration of culosis is discovered are sent to their family physi the medical departments in industry has more re cian. Our roentgenogram Is at his disposal, but cently been drawn to the general health of its em must be returned to our files so that we can later ployees. Attention to the control of tuberculosis compare the progress, of the disease and determine has been a very major issue. We believe that in at what future time those persons may be pro no adult group throughout the country can so nounced employable. much be accomplished in prevention and early Applicants with arrested or quiescent tubercu recognition of this disease as in our industrial in losis are placed at work after being informed of stitutions. their condition and instructed to return for pe Legislation varies in the different States regard riodic examinations. These examinations for new ing occupational disease but the ultimate objective employees, in this classification, are conducted of this legislation is clear: The general health of every three months. the employee must increasingly become the re It has been increasingly evident that our re sponsibility of the employer. While the status of sponsibility does not end there. We explain to tuberculosis has been debated by many legisla the employee that while he now has an arrested tive bodies, silico-tuberculosis is definitely com tuberculosis, it was once active. We encourage pensable. In the state of Illinois the new occupa him to have the members of his family examined tional disease disability compensation law went by the family physician. We feel that not until into effect on October 1, 1936. Dr. C. O. Sapping- then has industry wholly discharged its duty to ton states that "during the first year of the oper the community. ation of this law, 10.9% of disability claims filed 2. Periodic Examinations for Old Employees. were for pulmonary tuberculosis while silicosis These examinations are made at different times claims were 15% of the total."1 and for varied reasons: The corporation that is looking toward the fu (a) Upon returning to work after vacations. ture with the best interests of its employees in (b) After absence caused by an illness. mind certainly should be actively engaged in the (c) Re-employment following seasonal lay-off. problem of the control of tuberculosis. Many of (d) Transfer from one type of work to another. our industrial institutions have already shown, by (e) Medical department requesting the exam marked reduction of the incidence of pulmonary ination for some definite reason. tuberculosis, just how this can be accomplished. (f) Volunteer requests by the employee for Our own corporation has a very definite program such an examination. concerning tuberculosis. Little comment is necessary concerning these examinations except to state that every employee THE PROGRAM: 1. The Pre - Employment comes into our medical department for a general Physical Examination. Every prospective nhvsical check un at least once each vear 2* * x 1 ow (r t .t - ' |! CUMIFIU lUftilCT kiteastw. i46o Juni eq*j44c. ,i 7s"/ w AUTwom. ., 0,. Vigliani .. .... ` ., . . ' tn.MLUOMWOUMI O P1LX MUMCI 0 m iiTu* Two fatal cases of pulmonary asbestosis, t 1 _ woe.______P. K hass .med.Indust. u 26-52. ..'.40 Jia 22 128 June >3 < ttc . AMTMCTi The first of these ewe a concerned a wo can oho corked for thirty years i a Vr* actary using asbestos in the 'manufacture of cord. Thu second cocoa. corked fc U seven years in an asbestos factory. ; Her susceptibility to os ids increased itoile M2 ac she cas working and she suffered all; her'life fron bronchitis and asthoa. She died at the-age of fifty, with, symptoms of a lung disease, nearly thirty years b2 05 after having stopped cork. The autopsy showed interstitial sclerosis of the lur. end asbestosis bodies*. . \ . . ?p *HM i*. ~-r *t t* rr >%- **T - r $ M . ^ _____ _j " V"T : ****---~ --t* , ""IT ** OATS dlamecB. il,r JI2L or.suecwi AMTMCT WO* roe WtC ^r- SC-ALL-01986 SCF-FA-0704 DUE CASI MORTAL! DI ASBESTOSI POLMONARE# Prof. ENRIGO C. VIGLIANI I 5 'ii L'amianto e un minerale a struttura fibrosa: le sue fibre pm lungbe si prestano ad essere cardate, Slate, tessute; quelle pm corte ser- vono alia preparazionc di filer:, freni, isolanri, careoni, cternit, ecc. La molteplidta dcirimpiego dell'amiaato deriva dalla sua urilizzazione come matenale tessile e dalle sue proprieta isolanti. e incombustibili; la grande richiesta di manufatri di amianto da parte dell* industria moderna ha fatto si cbe la. lavorazione di questo minerale si sia piu che decuplicata 'u It nel volgere di una ventina di anni. Dal punto di vista chimico i'amianco e costituito prindpalmente da silicad di ferro e di magnesio: a seconda che prevale l'uno o 1'altro silicato Tamianto ba colore, proprieta e denominazioni diverse. Durante le vane lavorazioni deiramianto si sviluppa una polvere contenentc minudssime fibre del minerale, polvere che viene inalata dagli operai. Per mold anni si ignorA che essa potesse essere dannosa; Tosservazione di un caso di sclerosi polmonare da amianto fatta nel ipoo e pubblicata nel 1907 dal Dr. Montague Murray1 passo sotto silenzio, finche nel 1927-1928 furono descried alcuni casi mortal! di asbestosi in Ingbilterra per opera di Cooke2,a, Me Donald4, Oliver*, Seiler 7, Steward*, Gli studi clinici, radiografici e anatomopatologici reladvi a questi casi dcstarono yivo intqresse fra i medici del lavoro. Negli anni succes- sivi furono descritti in Inghilterra (Haddow Wood10, Wood c Gloynen, Seiler e Gilmourlfl, eccA nel Sud Africa ([Hallu, Sim eon Aa), negli Stari Unid (ZyncA c Smith 1S, Mills 1#) e in Germania (Beintker, Burescb l\ Holtzmann12, Rostoski30, lecc.), altri casi di asbestosi; ai quali feccro seguito accurad studi anatomo-patologici e mine- ralogici (Gloyne81, Beger , aA, a5 Koppenhofersa, Sundius e Bygden aT, Di Biasi*8). Osservazioni compiute fra gli operai di manifatture aamianto (Lovisctto ao, Mussa 30, Merewether , , Gerbts e TJcko88, Lanza, Dalla Clinica JAedica Generale della R. University di Torino: Direttora Prof. Carlo Gamna; c da]\'lsiituto di Medicine Industrials di Torino dcWEJSl : Direttore Prof. Enrico C. Vicliani. DUE CAST MORTAL! DI ASBESTOS! Me Connell e Fehnela4t e alcuni bellissimi lavori riassuntivi (Sparks Merewether 3a, Wood.e Gtoyne 97 ecc.) fecero riconoscere una notevolc frequenza di casi di sclerosi poimoaare riferibili alia ptolungata inalazione di polvere. Per tal modo venne dimostrata la pericolosita della lavorazione dell*amianto e si cosdtul la conoscenza della malattia polmonare che cssa pub produrre, malattia che era stata chiamata asbestosi. fondamentalinente noi sappiamo oggi che 1'asbestosi e una sorta di polmonite interstiziale cronica rivestente 1'aspetto finale di una sclerosi diffusa, non nodulare, del polmone. La sua patogenesi appare iegata alia penetrazione nei polmoni di minudssime fiore d'amianto e alia const- guente reazione del tessuto connettivo polmonare: nelle sezioni istolo- giclie dei polmoni asbestosici si vedono, accanto alia fibrosi e ad aree di enfisema, numcrosissimi aghi e fibre di amianto, alcuni dei quali ap- paiono nudi e altri rivestiti di un invoiucro di colorito giallastro, conte- nentc molto ferro, Gii aghi d'asbesto cosl rivestiti hanno aspetti curiosi e caratteristici e furono detti corpuscoli dell*asbestosi. Clinicamente la malattia inizia quando la diminuzione della super- ficie respiratoria dovuta alia fibrosi polmonare incomincia a farsi sentire; i primi segni sono la tosse e la brevid di respiro. Estendendosi la fibrosi la dispnea diviene sempre piu grave e ad essa si possono accompagnare sintomi di scompenso del cuore destro. AlTesame ogg;ettivo non si notano altro che i segni della fibrosi polmonare, piu evident! alle basi; la morte awiene per insufficienza respiratoria e cardiaca o per tubercolosi o, molto piu spesso, per malattie pounonari intercorrenti, specie broncopolmonitc. Le radiografie polmonari degli asbestosici lasciano vedere una dimi- nuzione della trasparenza dei campi inferiori e medi dei polmoni dovuta a una diffusa velatura e a un vario intreccio di ombre striiformi e retico- lari; in generate pero esse danno 1'aspetto di una gravita minore di quello che climcamente non sia. Data la scarsita dei segni clinico-radiologid, la mancanza di sintomi Veramente caratteristici e la frequente sovrapposizione di malattie inter correnti o di scompenso di cuore, la malattia e difficilmente riconoscibilc, se i dati anamnestid non mettono bene in evidenza la prolungata inala zione di polvere di amianto e se la esistenza di una sclerosi polmonare da amianto non e conosduta dal medico visitante. La grande difficolta della diagnosi clinica dell'asbestosi e riconosciuta da tutti i ricercatori e in realta i casi clinici diagnosticati e riportati sin- golarmente sono piuttosto rari. (Cooke a, 3 un caso (1924-1927); Oliver8 due casi (1926); Simson u due casi (1928); Seiler7 un caso (1928); Wood c Page99 un caso (1929); Haddour quattro casi (1929); Soper30 un caso (1930); Mills ,l\ un caso (1930); Lynch e Smith un caso (1931)! Seiler e Gtlmour12 un caso (1931); Stewart, Bntcher e Colemandute casi (1931); Baresch 18 un caso (1931); Beinther 17 due casi (1931)-, Ste 28 RASSEGNA MEDICINA INDUSTR1ALE wart., Tattersal e Haddow un caso (1932); Ellman 42 un caso (1933); 43 un caso (1933); Stroebe 44 un caso (1933); 4a un caso (1935): Egbert 40 un caso (1935); Martz 47 un caso (1935); Bobne 48 un caso (1936); Di Biasi 38 un caso (1937) e scnza citare 1 casi di carcinomi polmonari in asbestosici). - La maggior parte della, casistica di cui oggi disponiaxno deriva da ospedali per le malatcie di petto situati nelle vicinanze di manifatture di amianto (Wood e Gloyne , nel City o London Hospital)) videro in pochi iinni pm di xoo casi di asbestosi di cui 36 mortali), o da ricerche sistematicbe fatte fra le maestranze di tali manifatture (Merewcther ai,3a, Gerbis e Uckoa'\ Shull49, Me PheetersAlwens a\ Saupe5a, Lanza 641 Dreessen e collab,r,fi, Wedlerao ecc.); se non vi sono queste favo- revoli condizioni, la grande maggioranza dei casi di asbestosi viene all'e- xitus colla diagnosi di scompcnso cardiaco, di broncopolmonite 0 di tuber- colosi polmonare; diagnosi magari esatte in quanto alTepisodio terminale, ma dalle quali non appare la malattia primitiva e fondamentale. . In Italia, per esempio, e specialmente in Piemonte, ove vi sono nu- merose cave e manifatture di amianto nelle quali lavorano piu di iooo operai, non e ancora mai stato descritto un caso mortale di asbestosi; i pochi autori che si sono occupati deirargomento, Lovisetto 20 e Mussa 30, riten- nero anzi la malattia non grave in sc, ma solo pericolosa per il facile soprawenire della tubercolosi. Deve essere perb, a onor del vero, ricordato die nel 19x0, quando ancora la malattia era del tutto sconosciuta (salvo la pubblicazione di M. Murray 1 del 1907 nel Departmental Committee on Compensation for Industrial Disease) il Dottor Castagneri, medico con- dotto di Nole Canavese, descrisse come tesi di laurea un caso mortale di asbestosi polmonare complicate da tubercolosi: malauguratamente questa tesi non venne pubblicata, ma essa e visibile negli arcliivi delTUniversita di Torino e i pezzi anatomici di quel caso sono ancora oggi conservati nel Museo deiristituto di Medicina Legale della stessa citta. Mi pare quindi utile di riferire due casi mortali di asbestosi osservati nella Clinica Medica di Torino. L'interesse di questi casi non deriva solo dal fatto cbe essi rappresentano i primi descritti m Italia e quindi possono servire ad attirare Tattenzione dei medici su questa malattia professional, che certamente in Piemonte h piu frequence di quanto non si creda, ma anche per alcune altre considerazioni, Infatti essi per le particolari circo- stanze del loro sviluppo e del loro decorso si prestano egregiamente a di- scutere alcuni punci ancora controversi dell'asbestosi e principalmqnte quello dell*aggravamento della malattia cessata l'esposizione alia polvere. Inline la desaizione clinica di questi casi serve di utile completamento al bellissimo lavoro anatomopatologico che su di ess; hanno compiuto il Prof. Mottura e il Dott, Fagiano 57 e che verrb pure pubblicato su questo DUE CASI MORTAL! DI ASBESTOS!" 29 Caso i -- Am. Maria, a; 56, nata a Foggia. ................. Anamnesj: Lapazientc c secondogenita ai 13 figli di cui n morirono in te- nera. etb. Nulla da segnalare nell'infanzia e in gioventu, trarrne una affezione al- Tocchio sinistro che guari con esteso leucoma comeale. Sposata a 15 anni, non cbbe gravidanze, Fino all'eca di 25 anni si dedico a lavori casaiinghi, poi dal 1907 fino a dieembre 1936, e ciob per 30 anni, lavorb a Torino come operaia in una fabbrica di code. Durante quesco periodo non u mai soggetta a disturbi degni di nota, eccetto a volte im po' di;tosse scriza escreato; da qualche tempo perb la tossc era piu frequente ed era comparsa modica dispnea da sforzo, . Nd dieembre 1936 u colpita da un episodic influenzale con tosse ostinata pressoche senza escreato, dispepsia, dispnea durante il riposo e accentuantesi per t piu piccoli sforzi, talora senso di cardiopalma. Rimase a letto per circa 15 giomi dopodiche potb alzarsi e occuparsi delle faccende di casa accusando solo piu una certa astema, affanno di respiro c senso di palpitazione cardiaca durante la marcia e fariche onche di poca entita. Alla fine clel marzo 1037 la dispnea si aggravb nuo- vamente tormentando I'a. anclie durante il riposo in letto; l'astenia e il cardiopalmo si rifecero assai evidenti assieme a senso di peso alia regionc epigastrica; compar- vero edemi mallcolari mentre la diurcsi si fecc assai scarsa. . Per questa sintomatologia In. entro in clinica*il 9 Aprile 1937. Esame oggettivo: Donna di statura bassa, di costituzione robustn, in discrete state di nutrizione. E* inrensamente dispnoica e costretta a mantencre in letto la posizione seduta. Cute fortemente cianotica in specie ai volto e ovunque succu lents; edemi spiccati si notano al terzo inferiofe delle gambe, allc regioni lombo- sacrali e alle parti dcclivi dclF addome. Sistema Hnfatico superficiale indifferente. Polso frequente (102-108 battutc al minuto) ritmlco, piuttosto molle; respiri 44-48 ai minuto, superficial!, a tipo inisto. Temperacura oscillantc fra i 370 c i 38. A carico del capo vi e da rilevare solo un leucoma centraje dell'occhio Si c un'intensa danosi clci pomelli, delle orecchie c spedalmcnte delle labbrn. Tonsille e faringe alquanto arrossate. Al collo si apprezzano assai turgidc e pulsariti le vene giugu- Ian; riroide in limiti. .. Torace \ Regolarc di forma, simmetrico, un po' rigido, si espande poco nelle in- spirazioni; Apici: Arec di Kronig di eguale ampiezza bilatcralmente; suono plcssico chiaro, f. v. t ben trasmesso, respiro vesdcolare. Polmoni: bast polnionari scarsa- mente mobili. Suorio di percussione chiaro . nelle regioni superion, alquanto smor- zato bilateralmente, ma piii a D., verso le basi, AlFascoltazionc respiro vcscicolare ovunque, un po' diminiuto verso le basi ove si ascoltano numerosi rantoli a pic- cole e medie bolle in- cd espiratori. I rantoli si apprezzano pure numerosi, neUe regioni basali, in corrispondenza delle linee ascellari; appaiono in complesso piu fitti a D. che a S. Cuore: itto nel V spazio intercostale sull'ascellare antcriore; area di Orsi-Grocco normnle; a D. Tottusiri* relativa del cuore a livello della IV e V costa si estende fino a due dita trasverse all'estemo della marginostemale destra. Alla ascoltazione.toni assai frequenri, soffio sistolico sulParea mesocardica. Addome: piuttosto espanso, dolente la palpnzione della regionc cpatica; il c- gato giunge in basso a un dito al disotto della linen ombelicale trasversa; la milza non sTpalpa.-^rri: nulla di notevole, cccetto la presenza di evidenti edemi ai piedi e alle regioni malleolari e preribiali. Sistema nervoso indenne. Esame delle orine: quantity giomaliera cc. 500, A 1021, albumina velo, nel sedimento scarsi gl. rossi, mold gl. bianchi e cellule di sfaldaracnto. Es. ematolooico\ Hb 82, G. rossi 6.740.000; V. gl. 0.61. G. bianchi 7800 (Pol. N. 64, Eo, 2, Linf. 26, Mon. 8). Prcs- sione arteriosa Tqo/70 (Riva-Rocci). Rcnz. Wassermann, Mcinickc, Kahn negative. 30 RASSECNA MEDICINA INDUSTRIALS Esame radiografico; I cnmpi polmonari presentano un scminio di ombre a forma di piccole chiazze e 5trie, piij numerosc in vicinanza degli ili e dei margini del c11ore, ove si addcnsano c quasi conHuiscono' in opacity maggiori. II :polmone descry b pin colpito del sinistro cd e pure diffusamente velato specie nella rcgione apicale e sottoclavicolare, A sinistra fra le chiazze e le strie si vedono piccole aree irregolari di maggiore trasparenza, Ncl complesso a sinistra e visibile una certa disposizione raggiata dalle strie, ohe si presentano spesse anche 4-5 mm. e ad ombra tenue c sfumata. Le chiazze non lianno, se non molto raramente, un aspetto no- dularc, ma si presentano a contorni frnstngliati e irregolari, apparendo spesso come punti di incrocio 0 di sovrapposizione di tenui ombre di strie, Qualche volta pic cole chiazze sono centrace da un bronco. I margini del cuore sono quasi comple- camente irricoriosdbili,* l'area cardiaca appare perb alquanto ingrandita specie verso dcstra. Pure i margini dcll'ombra diaframmatica, particolnrnicntc a sinistra, sono sfumati. Alcune aderenze pleurodinframmatiche all angolo epatocardiaco e all'emi- diafrnmnia sinistro. Durante la degenza in Clinica, nonostance I'isticuzione di una energica terapia a base di salasso, diuretici mercurinli, uabaina endovena e analettici, * lc condizioni della paziente, dopo un transitdrio miglioramento durato a-j gforni, peggiorarono progressivamente. La pressione arteriosa si abbassb a valori di 90/56, la dispnea, gli edemi, la cianosi e la tackicardia si fecero ancorn pin intensi; 1 rantoli alle basi polmonari piii numerosi; la tempera turn ebbe qualche punta serotina sui 38,5-38,7, finchb Texitus sopravvenne il 25 aprile 1937, ^PP 1^ girn* di degenza. La natura della malattia che aveva portato a morte la paziente appariva estre- mnmente oscura. Fu fatta diagnosi clinica di scompcnso cardiaco secondario a sclerosi polmonare . L'esame nccroscopico (Prof. Vanzctti) foml nellc parti esscnziali il reperto se- guente:' Aumento dell'area cardiaca scoperta, cuore leggermente aumentato di volume. Apparnti valvoJari integri. Miocnrclio omogeneo, rosso.' Ventricolo destro del aiore notevolmentc dilotnto, muscolatura del ventricolo destro ipcrtrofica, Arteria polmo nare alquanro ectasica, con focolai di degenerazimie grassa. Polmoni \ Aderenze totali e ditEcilmente vincibili a sinistra; a dcstra aderenze limitate alle parti superior! del polmone. Pleure visccrali assai ispessitc. Entrambi i polmoni si presentano aumcritati di consistenza e'di peso. Alla sezione dei pol- moni si percepisefc meglio Taumento della loro consistenza. La superficie di taglio b variegata e permettc d1 osservare iina intensa sclerosi diffusa sotto forme di strie c di focolai irregolari di colore grigio non sporgenti sulla superficie. La sclerosi h maggiore nci lobi medii e inferior! dei potmoni, specie a dcstra, ma evidente anchc in quelli superiori. Qua c lit si vedono piccole arec circoscrittc di enfisema. Nel bronchi note di bronclute cntorale, Cangli linfatici ilari piii grossi, ma non piii duri che di norma: uno di essi appare caldficato, AU'infuori di questa ghiandola calcificata, probabile espressione del complesso primn'no, nessun altro segno di infc- zione tubercolarc pregressa o in atto. Modico versamento oscitico. Fegato, milza, reni da stasi. Nulla di importance a carico del conale digerente e degli organi genital!, In complesso; sclerosi intersti- ziale del polmone, dilatazione c ipertrofia del ventricolo destro, stasi nd grande dtcolo. ' Il risultato dell1esame nccroscopico confermava che lo scornpenso cardiaco era dovuto alia intensa sclerosi dd polmoni. Rimaneva ancora da risolvere ilmistero dell'eziologia ddla sclerosi polmonare, 32 RASSECNA MEDICINA INDUSTRIALE mistcro chc ncppurc gli esami istologici riuscirono a tucta prima a svelare. EssI ave* vano mcsso in luce un processo di poimonite cronica intersriziale o meglio gli csiti di qucsto processo polruonitico in forma di una sclerosi interstiziale diffusa non nodulnre. La fibrosi inreressava, con intensita aumentante dalPaplce alle bast, specialmcnce i setd inceralveolari e quelli interlobulari, che apparivano molto piu spessi die di norma; in grade minore gli spazi peribronchial! e pcrivascolari; qua e la zone di addensamento maggiori date sia aa focolai di atelettasia chc da processi di sclerosi piu estesi, ma senza aspetto nodularc e comunque sempre senza una netta disposizione concencrica det fasci delle fibre collagene. Numerosi focolai arinosi e lobulari di enfisema sparsi in mezzo alle zone sclerotiche. Che cosa poteva aver provocato una simile alterazione polmonare? Non la lieve sclerosi dcflarteria polmonare; non la lue, poiche gli esami sierologid erano stud negadvi; non la tubcrcolosi; nemmeno si trattava di una linfangite carcinomatosa. Col Prof. Mottura e i] Dotr. Fagiano, che si occupavano attivamente dello studio delle pneumoconiosi, osservai un giorno alcuni preparati Lstologici dei polmoni di questa donna. A medio c forte ingrandimento potei riconoscere in mezzo alle zone fibrotiche, nei setti interalvcolari e interlobulari e anche nel lume deg-Ji alveoli, vuoci o ripieni di detriri cellulari, di cellule desquamate p di liquido coagulato, in una parola un po' dappertutto, numerosissimi corpicctoli di colorito giallo-oro carico, stratiamente foggiati a forma di clava, di bastone, di manubrio da ginnasdea, di frammento di collana; corpicctoli che a un esame attento lascmvano riconoscere spesso nel centro unn fibra o un ago di sostanza molto rifrangente. II mistero si chiariva; la diagnosi diventava evidente: i corpiccioli crano i cost detti corpi dell*asbestosi ; la fibrosi polmonare una pneumoconiosi da polverc di amianto. Ncssuna speciale nbilita in questo riconoscimento: chi ha visto anche una sola volta i corpi ddl'asbestosi in preparad microscopic! o anche solo in riproduzioni microfotografiche non pub piu dimenticarli, tanto il loro aspetto e caratteristico. Ma come era possibile Fesistenzn di unn asbestosi polmonare, se il lavoro colI'asbesto non figurava ncll'anamnesi della paziente? L'inchiesta condotta fra i familiari della paziente rivelb chc essa, per circa 30 anni, aveva bensl lavorato a fabfa ricar corde, come essa aveva raccontato durante il rilievo dell'anamncsi, ma che queste corde crano di amianto e che la loro fabbricazione cagionava la diffusione neiratmosfera di una certa quantitb di polvere di questo mincralc. Caso a. -- N. Teresa, n, 50, nata a Note Cannvesc (Torino). Anamnesi: Nulla di importance nell'anamnesi fnmiliarc. Lo sviluppo fisico e psichico della paziente furono rcgolari: essa perb afferma di aver sofferto nelln prima infanzia di manlfestazioni riconducibili a una diatesi cssudativa, le quali si ripresentarono durante l'ctb scolnra, ccssando poi del tutto verso 1 iz anni. A iq anni superb rinfezione tifoide. In quello.stesso anno, e dob nel 1902, entro a lavorare in una manifattura torinese di amianto, ove rimasc fino all'eta di 21 anno, doe fino al 1909, epocn in cqi abbandono il lavoro per sposarc un uomo di 26 anni, sano, dal quale ebbe tre abort!, nessun figlio vivo. La paziente riferisce che fin dalla fanciullezza andava frequentemente soggetta a raffreddori invernali. Durante il lavoro nella manifattura di amianto comparve tosse saltuaria e si accentuo la tendenza ai raffreddori; il marito della pnztentc afferma che da quando egli la conobbe, essa ern affetta da tosse con escreato mucoso, tosse che si presentava a volte in forma di veri ncccssi ptu o meno lunghi. Nd 1912, a 25 anni, fu assunta m una concerin di pdli c venne addetta a un la- DUE CASI MORTALI DI ASBESTOS! 38 voro piuttosto fadcoso. Dopo 10 anni e do& nel 1922 fu colpita nel mese di no- vembre da febbre preceduta da brivido c accompagnata da access! di tosse stizzosa con scarsissimo escreato, insorgenti specie durante la notte e seguiti da dispnea e senso di soffocamento. Un sanitario fece diagnosi di asma bronchiale e prescrisse una terapia andasmatica dalla quale essa ritrasse alquanto. giovamento; la febbre cesso in 0-10 giorni e la tosse diminul molto, senza ruttavia mai scomparire. Rimes- sasi da questo episodic morboso la paziente non si send piu in grado di sopporrarc il fadcoso lavoro nella conteria per il pcrsistcre della tossetta, di una facile stanca- bilid e di un senso di affanno per i lavori pesanti e si impiegb per due anni alia Snia Viscosa, trascorsi i quali, tendendo la sintomatologia suaccennata ad accen- tuarsi, fu costretta a rimanere in casa accudendo solo piu al disbrigo delle faccende domestidie. ' NelTinverno 1926 doe a 39 anni essa fu nuovamcnte colta da brivido, febbre e violend accessi di tosse accompagnad da senso di soffocazione e dispnea. Fu nuovamente posta la diagnosi di asma bronchiale. La febbre si dilegub in pochi giorni, ma la tosse permase insistente fino a primavera inoltrata. Da allora la paziente riferiscc chc ogni anno, all' inizio dell' inverno, ritomavano gli accessi di tosse, a volte preceduta da brividi e da un po* di febbre, mentre il senso di soffocazione e di dispnea si facevano man mano piu evidend, comparendo non solo durante le fatiche o la tosse, ma anche indipendentemente da quests, in occasione di lievi lavori fisici. La tosse era piit insistente al matdno e dopo i pasti; la terapia anda smatica non apportava piu alcun sollievo, la malata sentendosi anzi ogni inverno pih stanca, piu tossicolosa e piu dispnoica dell'invemo precedence. Nd 1935, du rante un accesso violento di tosse, ebbe pure escreato abbondontemente rinto di sangue; nell'inverno 1936 fu colpita improwisamente, nel pomeriggio, da un accesso di soffocazione die durb fino al matdno seguente; dopo questo cpisodio si accentuh l'astenia e comparvc pure marcata disappetenza, Alrinizio deirmvemo 1936-1937 comparve senso di peso all'epigastrio e talora vomito, riprese la solita tosse invemale: V astenia era grande e la dispnea interveniva per fadche anche minime. Nel marzo 1937 incomincib a notare un colorito cianodco delle mucose e della pelle del Volto, die andb man mano accentuandosi. Nonostante il ricovero per- circa un mesc in un ospedale, le condizioni della paziente si feccro progressivamente piu prccarie finchc, essendo comparsi cospicui edemi agli atti inferiori, essa si fece ricoverare, il 10 gennaio 19381 in Clinica mecUca. Esame oggettivo: Statura alta, conformazione scheletrica rcgolare, condizioni generali discrete; peso Kg. 73.600. Colorito piuttosto pallido; cianosi intensa alle labbra, ai pomdli delle guance, alle orecchic e alle dita delle mani. Sistema linfa- rico superficiale indifference. Polso di frequenza 100 al minute, ritmico. Respiri 24. Temperatura 377. Pressione arteriosa 120/80. All'ispezione del capo si osserva che la cute e anche i bordi della lingua, le tonsille e la faringe presentano un colo- rito danotico, bluastra. Le vene del collo si disegaano assai turgide. Torace: angolo epigastrico acuto; fosse sopra e sotcoclavicolari evidend, spazi intercostali ristretti. Le escursioni respiratoiie appaiono molto ridotte. Appotato rsspiratorio: apici normal! per fonesi e murmure vescicolare. Il suono di percussione polmonare chiaro in alto va gradatamente smorzandosi verso le basi, le quali sono prcssoche immobili c nettamente ipofonetiche, la destra per una estensione e con un* intensid maggiore della sinistra. Il f. v. tu h ben trasmesso in alto, indeboHto, quasi abolito verso le basi. All'ascoltazione si notano su tutto 1'ambito respiro vescicolnre piuttosto aspro e numerosi rumori bronchiali sia 84 RASSEGNA MEDICINA INDUSTRIALS sccchi che uxnidi in- ed espiratori, i quali verso ]e basi vanno facendosi piu abbon- danci: quivi e specie a destra, il respiro si ode assai diminuito. . Cuore: L'itto non si vede nb si palpa, si delimica colla percussione nel VI spazio intercostale sull'ascellare anteriore. II margine sinistro dell'ottusiti relativa. del cuore e assai convesso e ingrandito; l'area cardiaca nppare pure ingrandita verso destra, ove giungc a circa a l/x dita daLla marginosternaie sulla IV costa. All'ascol- tazionc alia punta il primo tono appare un po' strasdcato, quasi sdoppiato. II se- condo tono e nettamente rinforzato sui focoiai della base, specialmente su quello polmonare. 1 Addomei Un po' tumido, palpabile, indolente. Segni di modico versamento libcro. Ii margine inferiore del fegato si palpa al livelio dcH'orabelicale trasvcrsa, di consistenza auraentata. Milza in limiti. Arti: edemi evidenti ai piedi e aile re- gioni malleolari; meno marcati alle radici dellc coscic e alle rcgioni sacrali. Sistcma nervoso normale. Esame dellc orinez quantita giornaliera cc. 400. Aspetto torbido, densita 1021, reazione acida, albumina presente ( + ); abbonaante sedimento latc- rizio con cellule di sfadamento e lcucocid. Esame morfologico del sangue: Hb 78, globuli rossi 4.300,000, val. gl. 0,90, globuli bianchi 6.400 (Pol. n. 72, Eo. 1. Linf. 22, Mon. 5). Reazioni di Wassermann, Meinickc, Kabn negative. Pressione vcnosa alquanto aumentata (30-35 cm HaO. Claude). Urea ipobromitica gr. 0.46 per mille. Con una puntura esplorativa eseguita alia base dcll'eraitorace aestro si estrassero circa 70 cmc. di liquiao con i caratteri di un cssudnto e il cui sedimento si dimostro costituito in prevalenza da linfociti. Esame radiografico del torace, eseguito dopo la toracentesi: I campi polmo- nari appaiono veiati nelia loro meta inferiore e quasi completamcnte opacati verso le basi. A destra, verso la base, si vede un pneumotorace parziale con un livelio liquido. L'opacamente dci polraoni h diffuso, come una nebbia che sale dal diaframma: solo in qualche punto, nelle zone medic dci polmoni, si intravede il di segno secondario del polmone.accentuate. Non ombre nodulari nk a cbiazze. Verso la regione cardiaca ropacamento polmonare k piu intenso csi confonde con 1'ombra del cuore, che appare fortemence ingrandita sia verso destra che verso sinistra. Le cupole diaframmatiche non sono visibili. Il lobo superiore sinistro e la regione apicalc destra hanno una trasparenza maggiorc del normale. Nei primi giomi di degenza in Clinica la cianosi, gli edemi e gli altri segni di insufiGcenza cardiaca furono molto spiccati. L'escrcato era pure abbondantc, muco- purulento: la riccrca del bacillo di Koch, prnticata ripetutamente, risulto sempre negativa. Con una energica tcrapia a base di tachidrolo, salassi, digitosan, le con dizioni migliorarono alquanto, Pemianeva perb sempre a carico del polmoni il re- perto di bronchite diffusa con numcrosi crepiti e rantoli, I'ipofonesi alle basi e rindebolimento del respiro specie alia base di destra. Dopo 15 giomi di degenza in Clinica, quando lc condizioni gcncrali erano in complesso soddisfaccnd, insorse febbre irregolare con massimi scrali di 38,2-39". Una velocity di sedimentazione diedc i valori seguenti: i` ora 35, costante di Katz 35. In corrispondenza del lobo inferiore di sinistra, sia anteriormentc che po- steriormente, si accentuarono l'ipofonesi e i rantoli a piccole c medie bolle. I feno- meni bronchiria, gli edemi e la cianosi aumentarono assai. Nci giorni seguenti la febbre ebbe un aecorso assai irregolare, mentre le condizioni gcncrali andarono sempre piu decadendo, con aumento degli edemi, della cianosi, della frequenza del polso e del respiro e con forte diminuzione della cliuresi. Inline exitus il 15 feb- braio 1938, dopo 36 giomi di degenza. Ri fatta la diagnosi clinica di scompenso cardiaco, bronchite cronica con w DUH CASI MORTAL! DI ASBRSTOSI 86 probabile sclcrosi interstiziale del polmonc, pleurite destra, broncopolmonite ter- minale. Dal punto .di vista dinico, ma specialraente anamnestico, era chiaro che la bronchitc cronica e la sclerosi poiraonate rappresehtavano i fatti primitivi e che lo^ scompenso di cuore dovcva essere secontfario ad cssi; solo la natura della sclerosi polmonarc appariva poco chiara, non essendosi * in principio attribuita imporconza al dato anamnestico della esposizione all'inalazione di poivere di amianto avvenuta per soli sette anni e a cosl grande distanza di tempo (30 anni) dall'exitus. Uautopsid (settore Prof. Mottura) diede, in breve riassunti, i tisultati se- gventi: Aumento dell'area cardiaca scoperta, versamento pericardico di piccola cntiti, Cuore globoso, alquanco aumentato nella sua meti destra; punta formata in egual misura dai due ventricoli. Aorta e nrtene coronatie normali; apparati valvolari integri. Le cavita del cuore appaiono fortemeate dilatate; attraverso l'ostio tricuspedale passa la punta di quattro dita. Prcsenza di trombi nei recessi dell'auricola destra. Polmoni: Cavid pleuriche obliterate, polmoni fortemente adercnti; la sinfisi h pcrb vincibile. Nelli parte dorsale della docda vertebrale destra esiste una sacca pleurica ripiena di pus. Arteria polmonarc dilatata; a sinistra moite sue diramazioni contengoao. trbmbi recenti, I polmoni si presentatio piii piccoli, meno elastid e, assat; piii consistent! che di norma, specie nelle loro parti medie e b|saU pve dipndf'a toccarli, impressione di un corpo duro-elasdco simile a gotirum,." M Jtaglio sono ossoi resistenti; la palpazioue e l'ispezioue della superficic dj ^io fanno rilevare I'esistenza di una estesa e avanzata sclerosi diffusa del pdenchima, piu grave nelle . parti medie e inferior!. Numerosissime Jc strie e i tocolai di fibrosi interstiziale, tilth non sporgenti sulla superficie del taglia. Pared bronchiali dandddie. e ricoperte di muco. Linfoghiandolc ilari tumefatte, non itidurice, foft^epte^\ahtra^ticbe. Nessun segno di tubercolosi spenta 0 in atto ne nei polmoni ne ticllei ;'lih~ -1*1 Nulla m particolaie a carico 1. minal digerentc; fegato e milza da stasi; r<mi pallidi, torbidi. j trombosi recente di saccata a destra; dilata- ^frddi polmoni: si vide una estesa fibrosi a tipo dif-jfcrmivo a\rfocolai, prevalente nelle parti medie e .^d-inferedtato a, ` |e zone di enfisema; quasi dappertutto segni di un i,^lri.. ,,r__ Corpuscoli parenchiraa polmonarc e anche nd lume di alveoli alquanto interiore che nel caso precedentemente ^picjija^fibrbsi interstiziale e ancor piu la presenza dei corpuscoli documentavano che la sclerosi polmonarc, fenomeno ^ ^rimitjiVp e determinants di tutta la evoluzione clinicn della ma T _ ^dktlfdS'hdursi all'inalazione di poivere di amianto durata soltanto sette if^essiadf ben 30 anni prima della inorte, /:, ^Gercherb ora di mettere in evidenza, in xnodo estremameute sintecico, delle due stone cliniche che offrono un interesse maggiore per la discussions: 36 RASSEGNA MEDICINA INDUSTRIALS Nel prime caso (A. M.) una operaia lavora per 30 anni a fabbricar corde di amianto tespirando un'atmosfera ricca di polvere di questo minerale. Durante questo periodo si sviluppa, con grande lentezza e senza dar segni di se, una fibrosi polmonare. In occasione di un episodio influenzale la fibrosi si rivela apparendo, quasi a un tratto, di una notevole gravita. L operaia, che fino aiiora aveva regolarmente iavorato, diviene in pochi giorni un'invalida. Brevita estrema di respiro, debolezza cardiaca e stasi nel grande circolo costituiscono i sintomi principal! della malattia. Ricoverata in Clinica, gli esami clinici c radiografici rivelano una probabile fibrosi polmonare diffusa con bronchite basale e una dilatazione con insufficienza di cuore. Nonostante una energica terapia la malata si aggrava rapidamente e muore, 16 giorni dopo il suo ingresso in Clinica, 4 mesi dopo la cessazione del lavoro. L'autopsia dimostra una grave sclerosi interstiziale cronica dei polmoni di origine asbestosica, con dilatazione del cuor destto e visceri da stasi. Nel secondo caso (N. T.) una donna lavora in gioventu per 7 anni in una manifattura di amianto ovc e esposta alTinalazione di polvere del minerale. Durante questo periodo insorge una tosse secca e molesta, a volte di tipo accessuale, tosse che non abbandonera piu la paziente per tutta la sua vita. Essa lascia la fabbrica a 21 anno per sposarsi; gia allora c una tossicolosa che soffre di frequenti rafEreddori e bronchiti. Pur tutcavia essa pub attendere a lavori faticosi, ma a 35 anni, dopo una bron chite asmatiforirie piu grave ed acuta delle altre, compaiono 1 primi segni riferibili a una fibrosi polmonare; un po* di brevith di respiro, dispnea da sforzo, facile stancabilica. Viene dichiarata un'asmarica e curata come tale. La donna cerca un lavoro piu leggqro e vi attende per 2 anni; ma la tosse, la dispnea 'e la debolezza si fanno piu insistenti e la costringono ad abbandonare ogni lavoro. Da 37 a 50 anni la sintomatologia si aggrava lentamente e progressivamente e ogni inverno, colle sue bronchiti e 1'esacerbazione della tosse e della dispnea, diviene piu duro da soppertare. Infine compaiono segni di scompenso cardiaco. La malata si fa rtcoverare in clinica; qui si rileva un grave scompenso di cuore con bronchite diffusa, un versamento pleurico a destra e si sospetta una fibrosi polmonare. Ogni terapia e vana; la malata muore 36 giorni dopo il suo ricovero in clinica, 13 anni dopo l'abbandono di ogni lavoro, 30 anni dopo la cessazione della inalazione della polvere di amianto. Lautopsia dimostra una sclerosi dif fusa interstiziale dei polmoni di origine asoestostca, una pleurite saccata a D, una grave dilatazione del cuor destro con visceri da stasi. . Nella discussione di questi due casi e conveniente sgombrare anzitutto il campo dal problema diagnostico, il quale pone principalmente due quesiti: DUE CASI MORTAL! DI ASBESTOSI 37 ' i) esacta la diagnosi di asbestosi polmonare? 2) L'asbestosi polmonare c stata realmente la causa della morte delle due donne? A1 primo quesito la risposta e data dall'esarae istologico dei polmoni. II ripo particolare della sclerosi .polmonare a forma diffusa interstiziale, la prevalcnza della sclerosi nei lobi inferior! e infine la presenza di innumereyoli fibre di amianco e corpi dell'asbestosi disseijiinati in tutto il parenchima polmonare, documentano in modo certo l'esistenza di una grave asbestosi dei polmoni del tutto sovrapponibile a quella chc h stata descritta dal punto di vista anatomopatologico da Me Donald \ Gloyne a\ Simson l\ Di Biasi 28, Wedler 50 ecc. (per i parricolari anatomici e istologici di quesri casi v. il lavoro di Mottura e Fagiano ar). Anche al secondo quesito si deve rispondere affermarivamente. Sc dal punto di vista radiologico e clinico, come vedremo, potevano csservi dei dubbi sulla estensione e sulla gravita della fibrosi polmonare, dal punto di vista anatomico e ancor piu istologico tale gravid era ben mamfesta, fiasta osservare per un moment qualcuno dei numerosi preparati istologici allestiti da Motturd e Fagiano, per convincersi della estrema riduzione della superficie respiratoria utile e del grave impaccio che le aree di fibrosi e di ennsema dovevano costituire alia circolazione del sangue nei polmoni. La causa conringente della morte e stata bensl, in entrambi i casi, lo scompenso cardiaco, ma esso riconosce la sua origine principale, se non uflica, nella sclerosi polmonare. Infatti il cuore di entramoe le donne non presentava segno alcuno di una pregressa infezione reumatica ne del miocardio ne dell endocardio e neppure manifestazioni di qualsiasi altro processo morboso capace di diminuirne la funzione o la resistenza; gli apparati valvolari, Taorta e le coronarie erano integre, e infine la dilata- efa localizzata esclusivamente alia merit destra del cuore. L'unica b^c^aiionc possibile dello scompenso di cuore era quindi quella di un gra^e aumento del lavoro del vcntricolo destro a causa della fibrosi pol monare, aumento che a lungo andare era risultato eccessivo per la muscolatura di questa meta del cuore la quale, come noto, e capace di ipertrofizzarsi soltanto in misura relativa. Chiarito il punto essenziale, cioe che la asbestosi polmonare e le sue dirette conseguenze furono la causa della morte delle due donne, vediamo quali elementi d'interesse possono essere tratti dalla storia delle malate. Per una fottunata combinazione le due stocie rappresentano due modi fondamentalmente opposti di decorrere della stessa malatitia. Nei primo . caso decorso silenzioso e asintomntico finche la malattia, rivelatasi in occasione di una affezione intercorrente di scarsa importanza, si e manifestata quasi airimptovviso e ha condotto in breve aU'exitus. L'operaia ha potuto lavorare praticamente priva di disturbi fino a pochi mesi dalla morte, Nei secondo caso dccorso cronico con tosse c bronchiti a ripetizione c in RASSEGNA MEDICINA INDUSTRIALS seguito affanno di respire, fenomeni morbosi cbe hanno condotto ad una invalidita dapprima parziale, poi totale, durata parecchi anni. La malata ha dovuto cessare ogni lavoro 13 anni prima della morte. Questi due tipi comspondono a due modi diversi di decorrere della asbestosi, la quale venne a volte dichiarata malattia subdola e latente, a volte malattia accompagnata fin dairinizio da tosse, bronchiti e dispnea molesta, a volte affezione costituita da un prime tempo di irritazione delle vie aeree superior! provocata dalla polvere presto seguito da un periodo di assuefazione piu o meno lungo il quale infine trapassa nel periodo della malattia vera con i sintomi proprii delle fibrosi polmonari (Merewether 81, Smpe5a). La morte sopravviene, secondo la maggior parte aelle descrizioni, da poche settimane a qualchc anno dopo la cessazione del lavoro polveroso. Non vi e dubbio cbe quesce descrizioni corrispondano a reali difEerenze nel decorso dell'asbestosi e non solo a insufficiente raccolta dei dad anamhestici 0 a maggiore o minor peso dato dai pazienti a disturbi, come la tosse e la dispnea da sforzo, ai quali non viene in genere attribuito un carattere di gravita; anch'io, che in questi ultimi mesi I10 avuto occasione di osservare parecchi casi di asbestosi, ho visto operai con avanzate fibrosi e pochi o 'punti disturbi soggettivi e operai con fibrosi relativamente modeste tormentati da tosse insistentc, brevita di respiro, dolori toracici, stanchezza c altri simili inconvenienti. Fra t due casi estremi vi i poi, come e naturale, tutta una serie di casi intermedi sia come numero che come intensita che come tempo d'insorgenza dei sintomi morbosi. II perche la asbestosi abbia un decorso a volte asintomatico, a volte accompagnato da un piu 0 meno vasto corteo sintomatologico, h di difficile spiegazione. probabile che cio dipenda in primo luogo dal differente grado di reatrivita delle mucose e dalla facilita piu o meno grande col quale viene liberato il riflesso della tosse, Viene comunemente afEermato che la pol vere di amianto, formata in parte di spicole e di frammenti aghiformi di fibre, i molto irritance per le mucose. Sono state desetitte con una certa frequenza Earingiti, tracheiti, bronchid e perfino congiundviti da. polvere di amianto (Quarelli BB, Wcdlcr s\ Bauer fle). Per contro e state aftermato non esserc la polvere di amianto particolarmente irritante, meno della pol vere delle manifatture di cotone. Viene a questo proposito citato il caso di un operaio che non poteva sopportare senza gravi accessi di tosse la polvere di cotone, mentre tollerava senza alcun disturbo la polvere di amianto (Merewether l). Come e noto il rivesdmento dei bronchioli terminali, dei bronchioli respirator! e degli alveoli, ove iniziano e donde procedono le alcerazioni fibrodche deirasbestosi, e privo di terminazioni sensitive, cosicchfc la tosse deve esserc interpretata come espressione non della fibrosi, ma di una concomitante bronenite oppure di alterazioni pleuriche. La fibrosi interstiziale DUE CASI MORTALI DI ASBESTOSI di pet se puo.evolvere sino a gradi avanzati senza rendetsi in alcun modo awertita, Anche la brevita di respiro e la dispnea da sforzo non sono segni che decorrano del tutto proporzionalmente al grado della fibrosi; come e note csistono individui che sopportano senza disturb! o quasi ridu- zioni ahche ample della superficie respitatoria e aim colpiti da dispnea e da senso di manennza 4*ana per riduzioni anche relativamente modcste. Inline anche il vario decorrere deile pleuriti secche, frequenti neirasbestosi polmonare, piib concorrere ad atricchire la sintomatologia morbosa sog- gettiva. . 6 quindi in ultima analisi la disposizionc costituzionale alle infiam- mazioni della mucosa delle vie respitatorie e la facilita alia tosse, unita alia resistenza individuale di fronte alia diminuzione del parenchima pol monare funzionante, che determinano l'entita e la precociti dei distutbi soggettivi delTasbestosi e quindi il modo di decorrere della malactia. Notero qui, per incidenza, che la tosse neirasbestosi si presenta spesso, come nella seconda malata, ad accessi, specialmente al mattino al momento di levarsi dal letto, accessi che possono perfino simulate quelli della pertosse tanto da venit scambiati con essi; scarsi sono per contro nella ibttetatuta (Oliver Th.60) accenni a episodi di carattere asmatiforme come quelli ai quali ogni tanto davano luogo la bronchite e la tosse pure nel mio secondo caso. Anche il quadro clinico-radiologico, che le due pazienti hanno pre- sentato durante la degeftza in Clinica, si presta ad alcune considerazioni. < Nonostante che, preso nel suo insieme, il quadto morboso possa apparire ptqssocW Cguale nelle due malate, tuttavia possono essere riconosciute sia . |^;^|9^raficamente delle aifferenze significative ai fini * .. *. in.considcrazione la bronchite. La prima malata . ^ a. isserdnsi'Stehte, ma secca o con scarsissimo espettorato: all'esame ^|^ipolmqni numetosi rantoli in prevalenza fini, localizzati alle due basi postetiormente e lateralmente. Nella seconda malata tosse pure insistente, ma con abbondatite escreato mucopurulento, rantoli c rumoti bronchiali secclii sparsi su tutto I'ambico, Ecco qui due modi di presentarsi della bronchite, di cut solo il primo e caratteristico della btonchite asbestosica. La' tosse secca con i fini rantoli basali e infatti frequentissima nelle asbe- stbsi di una certa gravita ma non complicate, ed io mi sono potuto convin- cere in successive osservazioni su di un ampio materiale che la mancanza di questo reperto & un fatto eccezionale. Il tipo della btonchite presentata dalTa seconda malata e invece banale e per nulla caratteristico deirasbe- stosi (Wedler 68); la malata, oltre che una asbestosica, era pure una .bron- chitica cronica in cui lo scompenso grave di cuore aveva, con la stasi pol- monare, accentuate i fatti bronchiali. Notero incidentslmence come la se- 40 RASSEGNA MEDICINA INDUSTRIALS conda malata abbia pure presentato spud striati di sangue: questo facoo non del cutto infrequente nelle asbestosi come in quasi tutte le malattie croniche dei polmoni, I'emorragia essendo quasi sempre cagionata dai fre quent* ed estenuanti accessi di tosse. Questi sputi ematici hanno probabilmenre contribuito, specie in passato, a far considerate come tisiri mold operai affetd da asbestosi; un tempo, quando la asbestosi era ancora imperfcttamente conosciuta, si ritenqva infatti che la maggior parte dei lavoratori dell* amianto morisse per tubercolosi (Scarpa ai, Collis Qa, Hoff mann 3). Un altro reperto frequentissimo nell'asbestosi, oltre alia bronchite, e 3uello della pleurite. I fini crepiri delle plcuriti secche sono difficili da isdnguersi dai rantolini e dai crepid, pur essi assai fini, della bronchite basale, cosicche la diagnosi clinica di pleurite in questi casi non e facile; ma e un fatto che all'autopsia di tutti gli asbestosici si trovano ispessimenti e tcnaci aderenze pleuriche e die mold di essi si lagnano in vita di dolori a tipo pleuritico localizzati prevalentemente alle regioni sopradiaframmatiche. Pure le nostre malate avevano ispessimenti e tcnaci aderenze pleu riche; la seconda aveva in piu una pleurite essudariva saccata alia base di destra. Le pleurid essudative non appartengono al quadro deirasbestosi; nel nostro caso la sua genesi e da riferire a renomem lnfiammatori pleurici o pleuro-polmonari favorid dallo scompenso di cuore, perchb h conosciuta la frequenza colla quale nei cardiaci scompensati con lpostasi e bronchiri si formino modici versamenti pleurici a carattere essudatizio. II pneumotorace patziale, visto alia radiogtafia, h dovuto alia penetrazione di aria nel cavo pleurico in occasione della piccola toracentesi praricata. Un altro sintomo sul quale conviene soffermarci tin istante b la febbre. AI loro ingresso in Clinica entrambc le malate presentavano qualchc movimento febbrile che perb non superava di solito, alia sera, i j8. Solo sub finem vitae si sono osservate nella seconda paziente elevazioni febbrili sui 39-3<Ji5* La asbestosi decorre di solito senza febbre; questa e sempre indice at qualdie complicazione. Io credo che nei miei casi la febbre' possa esser messa sul conto dello scompenso cardiaco, ricordando come spesso nei cardiaci scompensati con stasi viscerali, si osservino eleva zioni termiche irregolari. Nella seconda malata anche la bronchite e la pleurite essudativa concorrevano certamente ai movimenti febbrili; lq puntacc osservate pochi giomi prima della morce sono probabilmente l'espressione deirinfettarsi aeiressudato pleurico e deiristituirsi di piccoli focolai broncopncumonici che furono poi anche constatati all1 autopsia. Su tutti i sintomi finora elencati dominava lo scompenso cardiaco. Le malate erario piu che tutto delle cardiache e come tali avevano cercato ricovcro nella Clinica. In realta, a prima vista, tutta la sindrome morbosa e doe la bronchite con tosse, la dispnea, la rianosi, il senso di stanchezza, gli ederni malleolari, l'ingrossamento del fegato, i'bliguria, ecc. poteva DUE CASI MORTAU DI ASBESTOS! 41 riencrare benissimo ncl quadra di uno scompenso cardiaco puro e sempHce. l Sbno state solo Tattetita osservazione clinica, la valutazione di alcune sfu- mature come quella della cianosi insolitamente spiccata, della dispnea eccessiva, di un quadro tadiologico non interpretabile soltanto come poltnone da stasi o bronchite cronica, assieme alia riccrca della causa del prevalente scompenso del cuore destro, che permisero di affermare hel primo caso e di. sospettare nel sccondo I'esistenza di una fibrosi polmonare. rSe esame autopsico non avesse messo in evidenza una grave ed estesa fibrosi dei polmoni, permettendo cosl di riferire sicutamente la dila tazione cardiaca e lo scompenso ad un intoppo cronlco della drcolazione del sangue nel piccolo circolo le malate sarebbero state catalogate fra' i cardiopatici e la vera causa della malattia e della morte sarebbe rimasta ignorata. Ed e probabile che, come vedremo meglio in seguito, cosl avvchga per molti casi di asbestosi. Abbiamo gia visto come, airinfuori della sclerosi polmonare, mancasse qualsiasi altra causa che avesse potuto determinate la dilatazione del cuore destro e la siia consecutiva insufficient e come quindilo scompenso cardiaco si dovesse ritenere come diretta conseguenza aelTasbestosi polmo nare, 11 fatto che i due primi casi mortali di asbestosi descritd nel nostro Paese siano morti per insufficienza di cuore lascia pensare che questa complicazione sia piuttosto frequente nella pneumoconiasi da amianto. Infatti, scotrendo i protocolli dei cast pubblicati, si vede che in mold di essi la dilatazione e lo scompenso cardiaco furono riconosciuti gia in vita o alia nccroscopia: il caso di Mills1*, dopo aver lavotato 17 anni, morl pet blocco cardiaco con una estesa fibrosi polmonare; audio di Lynch e Smith 18 mod per scompenso cardiaco; in quello di Seiler e Gilmouria raMlbpsia-pap^^ che la morte era dovuta solaoiente a scompenso cardiaco cag*onata dalla fibrosi massiva diffusa, senza alcuna ' 'ag^luiiea. Nel caso di Stock 48 fu trovato ipertrofia e dila- Cardiaca; in'quello di Egbert 48 il ventricolo destro era dilatato, il cupre pesava 37^ gr,; in quello di White 48 alia radiografia il cuore era <c sicuramente dilatato . Nel paziente della Buresch 18 la morte sopravvenne in seguito' a insufficienza ventricolare destra: Tautopsia rivelo fibrosi polmonare, forte dilatazione e ipertrofia del ventricolo destro, modica iper trofia del ventricolo sinistro; in quello di Stroehe 44 fu trovato ipertrofia e dilatazione di entrambi i ventricoli, ma piu del destro (esisteva pero una lieve insufficienza mitralica ed aortica). Dei due pazienti di Saut>e 83 che morirono in uno il cuore e piu grosso che il pugno; il ventricolo sinistro e modicamente dilatato, il aestro h notevolmente irigrandito, specie nel cono. della polmonare, la muscolatura fortemente ipertrofica (spessote cm. 0,7))); nell'altro il cuore destro era ipertrofico^ e dilatato. Delle tre . autopsie riportate da Wedler 8B, in due fu trovato il cuore destro molto dilatato. 9 -- Ram. Med. Jndustr, - Nr. 1, ttyo. ;* t,-ii : ? If j 1i i5 I1 42 RASSEGNA MEDICINA INDUSTR1ALE La frequenza della dilatazione del cuore nella asbestosi polmonare e pure notata da Lovisetto p9, Mussa 30, Batter so, (das Herz isc durch die Ueberlasrung oft verbreitet und in seiner Funktion geschadigt), Holtzmann 10, (che la spiega col fatto che secondo lui la fibrosi attacca di preferenza le parti del poknoni yidni al cuore), Lanza ff4, Pendergrass "4, (in some istances, the cardiac silhouette is quite enlarged), Shull 49. Non tutti questi Aa. sono perb d'accordo sulla frequenza e la gravita dello scompenso cardiaco: alcuni, come Lovisetto ao, Merewether 3i, Haddow 0 non to nominano neppure fra le complicazioni o le cause di morte; aim infine come Ale. Pheeters30 ritiene cne Tasbestosi non impacci troppo il piccolo circolo e che quindi non vi sia ragione di un sovraccarico del cuore destro. In generalc coloro che non ammettqno la frequenza e la gravita dello scompenso di circolo nell'asbestosi sono quelli cne hanno compiuto in chieste in manifatture di amianto e hanno visitato operai idonei al lavoro, fra i quali sono in* realta rari i casi di dilatazione di cuore provocata dalla fibrosi polmonare. L'osservazione dei miei casi c la considerazione di quelli della letteratura mi hanno convinto che Tinsufficienza di cuore e una complicazione assai tardiva, direi terminale, deirasbestosi. Sc non soprawicne nessuna infezione gli asbestosici resistono finche rcsiste il loro cuore; quando questo cede, la fine e segnata a breve scadenza. Io ho calcolato che in un terzo circa dei casi nei quali e stato eseguito un controllo necroscopico {a morte abbia avuto come motivo pnncipale lo scompenso di cuore. Il caratteristico delle insufficienze cardiache aegli asbestosici e che esse si instaurarono tardivamente, ma una volta manifestatesi, non vengono arrestate da nessuna, per quanto energica, terapia cardiaca, Cost e stato nei miei due casi fe in altri (Saupe aa), nei quali e ricordato l'insuccesso della terapia digitalica c strofantinica. Veniamo ora a considerate il fenomeno primitivo e piu importante: la fibrosi polmonare. Nelle mie malate i segni clinici di essa si manifestavano soggettivamente nella brevita di respiro e nella dispnea, oggettivament?e nella cianosi, nella diminuzione delle escursioni respiratorie, nella quasi totale immobilita delle basi, nella ipofonesi piu spiccata nelle parti inferiori dei polmoni, neUaffievolimento del murmure vescicolare. Perb, come ho gia detto, durante la degenza delle pazienti nella Clinica la scena e stata taliiiente dominata dalla insufficienza di cuore che essa colic sue conseguenze si sovrapponeva ai segni propri della fibrosi, mascherandoli piu o meno completamente. Le radiograne, che ci avrebbero potuto dare utili indicazioni se noi avessimo in vita sospettato l'esistenza di una asbestosi polmonare nelle due malate, non ci furono allora di decisiva uti llta. Realmente io sono persuaso die nessun mdiologo per quanto esperto in questioni di pneumoconiosi avrebbe potuto in base a quelle radiografie far aiagnosi di asbestosi polmonare, tanto esse sono prive oi qlementi carat- i x DUE CAST MORTAL! DI ASBESTOSI 43 terisdci. Eppure ora, dopo aver studiato le radiografie dell'asbestosi riportate' nella letteratura e in special rhodo le belle riproduzioni dt Pender grass " di Saupe 52, " e di Wedler e dope aver eseguito personalmente radiografie a molti asbestosici, riconosco che le radiografie delle due inalatc rappresentano due frequend espressioni radiologiche dello stadio finale delrasbestosi, Le`due radiografie sono assai different Tuna dall'altra: basta confrontarle uh momento per accorgersi di do: nella prima senunio di ombre di piccole e medie dimension! su tutto il campo polmonare, con addensamento delle stessc lungo 1 margini cardiaci e le regioni parailari; nella seconda opacamento pressoche totale e uniforme delle due meta inferiori dei polmoni, con note di enfisema in quelle superiori. In entrambe peri, dove la lettura del disegno polmonare e ancora possibile, si riscontra la medesima nota fondamentale: ombre tenui, sfumate, striiformi o meglio reticolari, intrecciantesi in vario modo; non noduli veri, netd, delimitati e a si stand'come qiielli della tubercolosi miliare o della silicosl, ma piuttosto||qtdazze a concorni irregolari, prolungantesi in strie e confondentesfeito'1^parte nel reticolo; pseuaonoduli, se si vuolc, ma non nodulfcved^ncl senso cbe noi diamo in radiologia a questo termine. Mold Aa. banno dato buone descrizioni radiogranche dell'asbestosi polmonare e tutti insistono sulla tenuita e sfumatura delle ombre e suIla manc^nza di .noduli di tyia certa dimensione; nelle loro descrizioni si possono riconosceire due,, modi di prqsentarsi delrasbestosi grave, corrispondend agli aspetti presentad dai miei due casi; nel primo reticolo piu o meno fine o grossolano di ombre striiformi e piccole chiazze irre- ' ' ihtcqse nelle regioni sovradiaframmatiche e attomo al cuore; omufc a carattere indeterminate si elevano dal nubi di vapore, oscurando piu o meno iP||fii^oSo i due terzi inferioti dei polmoni e confonden- Bbpkeita. cardiaca, mentre le zone superior! del polmone sono ipertfasparenci per enfisema.' . Deve essere notato cbe mentre le forme ben svtluppate, ma non ancora gravissiine delTasbestosi presentano immagini raaiografiche in cui la grande intensificazione e la finezza del disegno secondario del polmone as&utnono aspetd fino ad un certo punto caratterisrici, le fotme gravbcomplicate da scompenso di cuore perdono quasi del tutto la finezza della trama e la delieatezza del reticolo e con cio la maggior parte delle caratterisrichc;.radiologiche delrasbestosi, I gravi ispessimenti pleurict, la dilataiione del cuore con consecudva compressione dei polmoni, la stasi pSlmobare e la' brbnchite cronica sovrappongono le loro ombre a quelle della fibrosi'asbestosica per dare un quadro, come nei miei cast, nel qiialcf^pub essere difficile anche la semplice diagnosi di una fibrosi pol- rftonare. . ' 44 RASSECNA MEDICINA INDUSTRIALS A'proposito della fibrosi notero ancora che nella prima malata, cli-. nicamente Hpofonesi basale e la diminuzione del respire e radiograficamente la velatura e le ombre reticolari e pseudonodufari erano maggiori a destra che a sinistra, A1 riscontro autopsico si e infatti constatato che la fibrosi era pm estesa e avanzata nel polmone destro. La prqvalenza della fibrosi asbestosica a destra e segnalata da parecchi ncercatori: OliverTM, Cooke2, Haddow, Merewetber21, BohneBauer S9\ essa potrebbe derivare dal decorso piu rettilineo del bronco di destra e quindi dalle migliori condizioni anatomiche per la penetrazione della polvere nei polmoni; vi e perci anche chi ha trovato fa parte sinistra piu spesso colpita della destra (Pancoast e Pendergrass0C). In un gran numero di cast la fibrosi h egualmente riparttta fra i due polmoni; la mia secohda malata appartierte, sia radiograficamente che anatomoistologicamente, a questo gtuppo. '* ' Infine mi par degno di accenno il fatto che, nonostante Testesa c grave fibrosi, non si sta mai ascoltato sui polmoni delle mie due malate un tespiro soffiante o bronchiale, ma bens! solo un rqspiro indebolito con carattere di asprezza. Cio h facilmente comprensibile pensando alle par- ticolarita anatomiche deH'asbestosi, per le quali quasi mai si verificano lc condizioni fisiche adatte alia proauzione del respiro bronchiale; e di- fatti mentre nella fibrosi silicotica si ode assai spesso in corrispondenza delle grosse masse tumoriformi un respiro soffiante, nella fibrosi asbesto sica un tale reperto e ecceziohale; ad csso accenna solo Wedler30, che lo riscontrb una volta in un caso particolarmente grave. Fra le particolarifa degne di interessc che i miei casi ptesentano deve essere pure ricordato che in entrambi non esistevano, ne clinicamente nb anatomopatologicamente, segni di tubercolosi, alTinfuori della componente linfoghiandolare di un antico complesso primario, osservabile nel primo caso. Questo fatto mi spinge ad accennare, sia pur brevemente, ai rapporti fra asbestosi e tubercolosi. nota la grande frequenza colla quale la silicosi si complica con la* tubercolosi, Secondo studiosi stranieri degni di fede, il 60-70 /Q dei silicotici muore per il sopraggiungsre deli*infezione tubercolare; in Italia vi e motivo di ritenere che questa percentuale sia ancora maggiore, Le osservazioni statistiche, cliniche, anatomopatologiche e sperimentali hanno dimostrato che la silicosi favorisce grandemente Tinsorgenza della tubercolosi e che fra queste due malattie esiste una grande frequenza d'associazione. PerTasbestosi, sclerosi polmonare grave quanto fa silicosi, si dovrebbe teoricamcnte ammettere una eguale predilezione del bacillo del tubercolo. Tralasciando antiche osservazioni (Scarpa61, Collis0a, Lovtsettoao, Boll,* francese dell'Ispettorato del Lavoro del 1906flfl) che parlano di vere stragi compiute dalla tubercolosi nelle manifatture di DUE CA5J MORTALI DI ASBESTOSI 45 amianto (osservazioni fatte in un'epoca in cui non esisteva igiene alcuna nellc fabbriche e in cui la confusione fra tubercolosi e asbestosi era rqsa tncvitabile dali'ignoranza di quest'ultima forma morbosa) sta di fatto che si ammette oggi dai piu, che. fra asbcstosi c tubercolosi esistano bensi rapporti ma che cssi siano meno. stretti di quelli fra silicosi e tubercolosi. . Gli autoti inglesi (Wood e Gloyne1VT, Merewether 3\ ecc.) i quali hanno dell'asbestosi la maggiore esperienza, affermano che essa, specialmente negli stadi avanzati, favorisce lo sviluppo dell`infezione tubercolare, pur riconoscendo che il pericolo e minore che nella silicosi. (The added risk of tuberculosis may be in asbestosis, it is less than that associated with silicosis. MerewetberSfl). Le loro staristicbe danno una freemenza rimarchcvole di asbestosi complicated con tubercolosi: in quella di Wood e Gloyne87 su roo asbestosici ricoverari in un Ospedale WeaUr ") basata per lo piu su inchieste compiute fra: i vlaVijifeaitriri delle manifatture di amianto, non esisterebbero stretti rapportrfra asbestosi e tubercolosi, benche vi sia alcuno (Bobne4a) che li . affermi; eli amcricani, seguendo i risuitati delle loro inenieste (Eama64' SEhII49, Dreessen0*) e Topinione espressa da Gardner e Cuhmins 98 in seeuito ai loro favori spcrimentali, non ritengono anche cssi che la tubercolosi costituisca un grave pericolo nelle manifatture di amianto* Delle tre autopsie di asbestosici praricate finora in Italia (i miei due icasi^e;.uno del Dr, Castagner*, non pubblicato) in due non esisteva ^"'Ij^fe^^^sisteva una polmonite caseosa, Indubbiamente il della raccolta di mblto materiale per essere J-rfiS !i|MpPpbssibile che da Paese a Paese varino quelle condi- 8* emche3 e ambientali che hanno un gran valorc nella diffusione done tubercolare. Dopp aVcr commentato e discusso i punti salienti del quadro mor- boso presentato dalle mie due malate desidero riaffcrmarc, come conclu- sione, il concetto che piu volte & gia affiorato nelle pagine precedent!: che cipi la diagnosi di asbestosi polmonare h. una diagnosi normalmente difficile. Molti sono i fattori che concorrono a rendere difficile quests diagnosi, che teoricamente parrebbe assai agevole: i principali sono i seguenti: esiguita del numero degli operai che lavorano 1'amianto in confronto al numero totale degli operai e quindi relariva rarita della itmbtria; appartenenza della maggior parte degli operai delle manifatture d'amiartfo aue Industrie tessili e quindi indicazioni di anamnesi lavorativa (cardatore, tessitore, filature) che appaiono innocue e non sollevano alcun sospetto di malatria professionale; tenuiti delle alterazioni radiografiche 46 RASSEGNA MEDICINA INDUSTRIALS polmonari scopribili a volte solo con una tecnlca radiografica perfetta; mascheramento della fibrosi polmonare asbestosica per opera, della tuber- colosi o dello scompenso di cuore; frequenza della morte degli asbestosici per malattie intercorrenti acute, in special rnodo polmoniti e broncopolmoniti; ignoranza fra i medici, e ancne fra molti medici del lavoro, della esistenza di una grave fibrosi polmonare da asbesto; mancanza di sintomi o di segni veramente carattcristici o patognomonici di questa xnaiattia. Certo durante le inchieste nelle' faobriche (Merewethera\ Lanzaa4,5\ Me. Pbeeters ao, Shull i0, Dreessen ffa, Lovisetto at\ Mussa 30, Gerbis e Ucko 33, Saupe aa, Wedler e facile riconoscere un certo numeto di asbe.stosieijma aftro e visicarc gli operai di una manifattura d'ataianto coll'in tent di scoprirvi i casi di sclerosi polmonare, altro e far diagnosi di asbe- stosi ^ letto di un ammalato grave, sofferente di debolezza cardiaca o di broncopolmonite o di tubercolosi. . . . Alle difficolta di una esatta diagnosi clinica hanno accennato gia pa- recchi studiosi del problema ddl'asbestosi: Wood e Gloynear scrivevano nel 1934 che non vi c affatto da sorprendersi se solo dopo morte l'anatomo- patologo scopre i segni di fibrosi polmonari rimasti inaiagnosticati in vita. Donnelly 60 vide 15 casi di asbestosi i quali tutti, meno uno, erano stati diagnosticati da altri medici come tubercolosi. Wedler ao ricorda che 23 operai delle manifatture d'amianto da lui studiate, affetti da asbestosi, si crano precedentemente fatti visitare piu volte da altri. medici per disturbi riferibui alia loro fibrosi polmonare; la diagnosi di pneumocomosi fu fatta una sola volta! II giudizio piu frequente fu quello di pleurite, o bronchite o tubercolosi. Egli conclude che la diagnosi di asbestosi viene fatta solo di rado esatta, benche le cose siano ora alquanto migliorate nel senso che gli operai sanno che il loro lavoro h pericoloso e nc informano il medico in occasione delle loro malattie. Per questi motivi io ritengo che molti casi di asbestosi siano anche in Italia passati inosservati. Cio vale da noi specialmente per la provincia di Torino, ove sono accentrate le principali cave e manifatture a amianto e ove i casi di asbestosi, almeno a giudicare da quelli capitati quasi contemporaneamexite alia mia osservazione, non devono essere del tutto infroquenti. Solo istruendo i medici sull'esistenza di questo particolare tipo di pneunioconiosi e convincendoli della necessity di raccoghere per ogni operaio malato una approfondita e minuziosa anamnesi lavorativa, noi po-* tremo sperare che questa malattia squisitamqnce professionale possa essere riel future piii frequentemente riconosciuta e diagnosticata. Vengo ora, dopo aver discussa la parte clinica, al rilievo piu impor tance che i miei diie casi mi permettono di fare.' Esso riguarda il problema prognostico dell'asbestosi e piu precisamcnte quello della, progressione della malattia cessata l'esposizionc alia polvere d'amianto. : .. DUE CASI MORTAL! DI ASBESTOSI 47 * Tale problema e stato solo da poco tempo aftacciato e si pub dire non sia ancota stato risolto. Per la silicosi noi sappiamo ormai con sicutezza che essa,, astrazion fatta dagli stadi iniziali, ha tendenza fatalmente progressiva anche dopo Tallontanamento dal lavoro polveroso; rincertezza che invece ancora domina nel campo dell'asbestosi. e dovuta alia sua scoperca relati- vamentc reccnte e alPesiguith del rriaterialc a disposizione adatto per un simile, giudizio. Lovisetto 30 afferma recisamente che cessando I'inaiazione della polvere, Tasbestosi si arresta nella sua evoluzione; Shullritiene che i qasi iievi migliorino con l'allontanamento dal lavoro, ma che tale proba bility sia assai minore nei casi avanzati; comunque Pasbestosi non sarpbbe almenb primitivamente una malattia progressiva. Wood e Gloyne 3T vi- dero pazienti le cui condizioni rimasero stazionarie per parecchi anni dopo la cessazione del lavoro e percib ctedono che anche quadri gravi di fibrosi possanb essere compatibili con molti anni di lavoro leggero in ambiente sano e non polveroso. . ; : Alcri Autori sono meno ottimisti: per Bohne 48 rallontanamento dal lavoro serve4s0lp|pecyi ,casi iniziali, ma non piu quando vi e cianosi o di- spniccsj|,(; ^ ,^a la malattia p_ rogwredisce lentatmente anche dop. e la^^^a^idh&ldeJPmalazione della polvere; quando poi compaiono corpu- sopli < tWPasbestosi nello sputo, la malattia sarebbe decisamente progress siVai. Aliens 51 e assai pessimista sulla prognosi dell'asbestosi; in un suo caso la malattia progredi decisamente anche dopo la cessazione del lavoro; Pendergrass 84 ritiene che quando 1'asbestosi pub essere diagnosdeata ra- diograheamente, c< the condition is likely to become progressive, c cib a causa della fissazione dellc stmtturevpolmqnari secondaria alia parteci- pazione .della pleura al processo fibrotico. Infine alcuni, come Lanza S4, ^i^p^ibile at' momento attuale dire se Pasbestosi progredisce, ' cessazione del lavoro polveroso. vede come i periodi di osservazionc dopo rst ricetcntonhanrio pronunciato il loro parere sul problema [jfl'l^vprpgfessivita dellasbestosi siamo piuttosto cortt: essi servono tutt al pinker up:.giudizio sul destino dei casi avanzati o gravi, ma non per affer- mare sePasbestosi fin dal suo inizio abbia o no tendenza decisamente pro gressiva. Qualsiasi osservazionc ben documentata e protratta per un lungo peripdo- d^-anni e a questo riguardo preziosa. ^ '^p!^i||?secdnda tnalata, che avendo lavorato per sette anni in gioventu epp ramianto e morta di asbestosi dopo trent'anni dalla cessazione del la voro .polveroso, rappresenta per la sproporzione fra durata delPinalazione e intjervalio ra il cessare di quesra e la morte un caso del tutto cccezionale ^ub nella letteratura. v' ./'"ti sua anamnesi ci permette di ricostruire la progressiva evoluzione d^Ua jfj^rosi polmonare, evoluzione che, come hanno aimostrato Mottura ^ifagi.ano collo studio istologico, era ancora in atto e vivace al mo- 48 RASSECNA MEDICINA INDUSTRIALE mento della morte. Nei polxnoni si sono trovaci inmimerevoli aghi di amianto, conficcati per ogni dove nel parcnchima e poiche la causa della progressione della nbrosi risiede certamente nella presenza delle fibre di amianto nel tessuto polmonare, sia che si ammetta una loro azione chimica, sia che si ritenga, come oggi appare piu probabile (Mottura e Fagiano 57) la loro azione di natura essenzialmente meccanica, la evoluzione progressiva della malattia appate l'evenienza piu logica e naturale. Ci si potra al piu nel caso speciale chiedere se la tosse insistence e continua e le bronchia di cui la malata soffriva abbiamo potuto, coi bruschi e violenti movimenci che esse imprimevano alia cassa toracica e ai polmoni, aver accentuata Tazione meccanica delle fibre e cosi favorito un piu rapido e intenso progredire della fibrosi. Questo mio caso dimostra chiaramente che una asbestosi anche iniziale, cioe tale da permettere ancora per parecchi anni un lavoto pesante, puo progredire anche al di uori di ogni ulteriore inalazione efi polvere di amianto fiho a un grado tale da cagionare la morte e pertanto nveste una particolare importanza pcrche, pur dovendosi tenere nel debito conto il rattore predisponente costituzionale, esso da la prima convincente dimostrazione della natura primitivamente progressiva delFasbestosi polmonare. ' RIASSUNTO . Vengono per la prima volta in Italia descritti sotto laspetto clinicoradiologico due casi mortali di asbestosi polmonare. , II primo riguarda una donna da 56 anni che inalb per 30 anni polvere di amianto. La fibrosi polmonare che ne consegul decorse in modo asintomatico finche, in occadone ai un episodio infiuenzale, si rivelo imptowisamente nella sua gravity e condusse a morte dope soli quattro mesi dalia cessazione del lavoro polveroso e dopo poco pih dall'inizio della sintomatologia. II secondo conceme una donna di 50 anni che inaid polvere di amianto per soli sette anni, dai 14 ai zi anni di erb. La iniziale fibrosi polmonare che pe derive fu fin dal suo insorgere accompagnata da tossc molesta e facility alle bronchiti; tuttavia permi$e l'esecuzione di lavori pesanti per 15 anni, in capo ai quali risulto cosi progredita da costringere la malata a occupazioni leggere e infine a rimanere a casa per iz anni, invalida e oppressa da tosse, bronchiti asmatiformi, dispnea. La morte soprawenne trent'anni dopo la cessazione del lavoro colFamianto e piu di altrettanti dopo l'inizio della sintomacologia morbosa. II difference mode di decorrere della fibrosi polmonare e alcune pardcolarid clinico-radiologiche presentate dalle due malate hanno permesso di discutere alcuni aspetti del problema deti'asbestosi. Viene cosi ricordato come la fibrosi polmonare da amianto possa decorrere in una forma latente asintomatica e in una forma precocemente accompagnata da sintomi molesti e debilitanti; vengono ricordati i prindpali elemetid diagnosdei come la tosse, la bronchite, la brevity di respiro, le pleurid secche, i segni fisici della fibrosi polmonare e viene aftermara la frequenza dello scompenso cardiaco come complicazione terminale; DUE CA51 MORTALI DI ASBESTOSI 49 Taspetco radiografico dell'asbestosi grave viene descritto nelle sue due variety piii frequenti e vengono ricordari i rappord fra asbestosi e tubercolosi. fi fatta innne presente la difficolta della diagnosi deli'asbestosi polmonare specie negli scadi terminal!, quando complicazioru di diversa natura possono mascherare, sia di- nicamente che radiologicamente i segoi pill carattcrisdd della fibrosi diffusa cronica interstiziale asbestosica. . # L'interesse prindpale della pubblicazione b perb conferito dal secondo caso illustrato, nel quale a un breve periodo di esposizione alia polvere di amianto segul un periodo di treut'anni durante il quale si sviluppo una fibrosi asbesto- sica mortale, La lunghezza del periodo intercorso fra cessazione del lavoro con I*amianto e morte per asbestosi e del tutto eceezionale e unico nella letteratura, e cosdtuisce la prima documentazionc sicura che uria fibrosi da amianto di grado lieve pub progredire fino a un grado mortale al di fuori di ogni ulteriore mala- zione di polvere; in altre parole che T asbestosi b, al pari della silicosi per quanto con un meccanismo diverso, una sderosi primidvamente maligna e progressiva dei polmoni, AUTORI CITATI ' i. 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