Document RaEer83rY5L1Qb8Ga2kZY56g7

FILE NAME: Saranac 7th Symposium (SSY) DATE: 1952 DOC#: SSY012 DOCUMENT DESCRIPTION: Transcript of Presentation by K.D.J. Urban - Industrial Hygiene Studies of Coal Miners in US PNEUMOCONIOSIS IN COAL MINERS Chairman: PHILIP DRINKER* Sc. D. Industrial Hygiene Studies of Coal Miners In Two Geographical Areas in the United States Discussion B. D. J. Urban Radiological Classification Discussion Charles M. Fletcher, M. D. Pathology of Coal Workers* Pneut- .conioala Discussion Arthur J. Vorwald, M. D. Epidemiology of Coal Workers* pneumoconiosis in Wales Discussion Charles M. Fletcher, K. B. i j 5. BY DOCTOR VOBWALPs It*s past our time to begin and there are a few announcemen i which I should like to make before the formal | opening of the morning session. j Again, to remind you, those of you who have not registered, please do so at the Johr. Slack Room. Also, t o-J norrow night, on Wednesday, at eight o'clock, there will be a demonstration of colored photography by the Ansco Com pany in the main ballroom of the Saranac Lake Hotel. Those of jou who are interested in color photography, I know, will be interested in what they have to present. Also, 136. . there are a number of you who are Rotarians and today being i | Tuesday# the Rotorlens will meet this evening at the Piah i and Game Club at six o'clock. The Pish and Game Club is on | the outskirts of Saranac Lake and should you inquire, I* ! certain that you will find your way there. It sounds very i| interesting when the Rotarians rcoet at the Pish and Game j; club instead of at noon time at the hotel, because it | always means something extraordinary in food end other i things, so if you wish, you're welcome to go there, to rneko tip your Rotary* The banquet on Thursday night, as you will note from your agenda, there is to be a banc -.at on Thursday night, and I wish to announce that ladies are cordially in- rited to the banquet. There will be a good many there, so | those of you who are accompanied by a lady, plaas bring I ! them* I With that then, we will enter our - or begin ear j| sessions for this morning, and our Chairman certainly needs f no introduction to you -- Professor Drinker, who is Professor . 0f industrial Hygisro at Harvard* Doctor Drinker. J l; BY DOCTOR DRIireiR: : Doctor Vorwald, Ladiea and Gentlemans j I'd like to ' make It clear to those whom I don't happen to kno* parson- j ally that I am not a physician and if questions should, by i any chance, come my way vuich are nv- 'leal, I take sec.id___ j place to no one in the matter of evasion an. I will them and pass them along to somebody else. The first paper this morning ia by Mr. Urban of the Laboratory here, on Industrial Hygiene Studies in Coal Miners in Two Geographical Areas in the United States. BY MR, URBAN? Coal is a sedimentary rock which, because of its high energy value, has been and is of outstanding importance to man. Coals occur in all geologiacl ages aince the pevon- ian period about three hundred million years ago. World wide distributions of coal originated in the and in the periods and in the later tertiary period, most of the lignites or low ranking coals of tbs i world were formed. J The extensive distribution of the Individual coal seams implies swamp accumulation on broad deltas, coastal plains and broad interior lew lands where shallow waters rest throughout the year. All ordinary coals are of vege table origin. In the sedimentary cycle of coal, the im mediate source of materials wore the prolific p l ^ t tree growths and the carbon dioxide which was drawn fr-m the surrounding atmosphere and surface waters. The trees and plants which fell into the swamp , waters underwent partial decay and the residue accumulated ; on the bottom of the swamps to form peat, which is the first takes feck page 137. t EUfaJBBB* I M i i i sedimentary rock which, bseauss of its high energy valo, haa boan aai is of outstanding importance to sfisn. Coal> occur in all geological ago* sine* ths Daroaian period about thro* M U U y w r . *v>- V orld-vld* d ir t r t h -io o . = f .trf to to. * to to. " 4 to to. lator torti^T 5rld, aort t to. lis^-to. r to. MtotoC etol* of the wxid Sera fersed. 3 O , extensile distribution of tbs Individual coal aeaaa ispUse a e m f l i U o on M l deltas, coastal plains and M interior lorn i ^ vbs* shallow waters rest throughout ths> year. M l erdisssy coals aro of vegetable origin. In tbs ssdisntary cycle of o m I, m > ixsaediato source of aaterials wore th* prolific slant trs growths and the carbon dioxide which was drawn from the sasroundisc ataosphere giv* surface waters. me tress and plants which fall into the m m ? waters undsrwnt partial decay end the residue accujsulatad on the botton of the ewanps to form peat, vfetoh is t'a first 138. atage of coal, all coal.. It ha. been estimated that from L25 to 150 year, of tine of accumulation were required to produce the equivalent of one foot of bituminous coal. F r 175 to 200 year, were required to produce one foot of anthrteite coal. An essential to coal foliations i. the arreet of bacterial decay In the submerged vegetable matter before complete destruction t akea place, so that there is some residue to accumulate. This is brought about fron the decaypromoting bacteria to render the water toxic to themselves. 1 The type of coal eventually formed depends on the environment, the kind of plants and particularly on the dur ation of the bacteria decomposition. Kay haV6> th* flrat slide, plea.et In non-technical terminology, four main type, of coal are recognized, anthracite or hard coal, bituminous or soft coal, canal, which is actually a special type of bituminous coal, and lignite. These types may be fiu-thar subdivided into ranks. Each rank designates coal of spec ific energy values and chemical and physical properties, j semi-anthracite, intermediate coal between anthracite and | bituminous; there are actually five different kinds of j bituminous - sub-bituminous and brown coal are intermediate between bituminous and lignite, andhracite being termed as j the coal of the highest type and lignite the lowest type. | Peat is a fuel. It's not a coal, but a mixture ; 139. of partly decomposed vegetable matter In which bacterial action, for tha moat part, has bean interruptd. Subse quent physical and chemical changes produce coal of the above ranks. Where these changes have reached completeness, graphite is the result. Physically -- rather, chemically, coals contain hydrogen, carbon, oxygen and impurities either in simple elements or in complex combinations. The chemical changes which occur when the higher rank coals are formed from peat are the progressive elimination of water, oxygen and bitum inous - either the solid and somit-solld hydrocarbons, the increase in carbon as fixed carbon in vola&le matter, tha consolidation of hydrogen development, heavy hydrocarbons, and an increased resistance to solvents, oxidation and heat. Some of the physical changes which may occur in coal formed from peat, in the highest ranks, concern the by-products of those coals of the higher ranks -which con tain lignose, gums, waxes, oils, resins and fats. Those resins and waxes which are less assailable by bacterial action are present in most coals* Coal beds occur within so-called coal regions j which consist of alternating baas varying in thickness, of j sandstone, shale, clay, almost -- mostly of fresh water j origin. A coal measure generally contains several coal j seams separated by sedimentary depositions of these various j minerals In Pennsylvania, for example, there are 29 coal seams aggregating 106 feet of coal with beds varying in thickness from a mere film up to 100 feet. The famous | Maiaot seam is fifty to sixty feet thiok. In Alabama, there | are fifty-five coal seams# In England, the aggregate j thickness of coal is 85 feet and in Germany 120 feet* | Now, during the past several years, the Saranac | Laboratory has conducted, industrial hygiene surveys in a number of underground coal mines located in various coal fields throughout the eastern section of this country# j Data from such - from six such surveys has been selected j for presentation# Each of these mines extracted a bitumi nous or soft coal from a different coal seam, with the ex ception of two mines, five and six which I'll show you latex which worked in opposite ends of the same seam# They ranked in size from employment of about 300 j! to 1,000 men# The deepest mine was about 600 feat below j; surface# All of the mines were entered either through jj vertical shafts or inclined slopes. Modern methods of i! mechanized raining were followed in each case, utilizing j 1! both track and trackless type of equipment. A limited j , j : amount of hand work, hand shovelling into conveyor pans was j also done All i mines ware generally regarded as gaseous# ; il*l* Considerable attention in each, case was, therefore, given to safety, to ventilation and dust control. Now, for these reasons, data from the - from these six mines can be com pared* It is our furtnar belief that some of the conclu sions derived from these studies can be employed also through other coed mines, even coal min tea of the anthracite type* Our primary concern in these surveys was for hazards of a respiratory significance* The nature an, effect upon man of the gasses commonly encountered in bituminous coal mines, gasses like methane, carbon dioxide, carbon monoxide and oxygex:-deficient air are rather well established* Our in vestigations were directed mainly, therefore, to a study of the air-borne dust, to which the workers wore exposed* | May we have the first slide, please? How, arly ] in our investigations, it became apparent that a number of j different minerals would be pi '5sent in varying proportions j throughout the same coal seam* A method was developed by us for tbs collection of air-borne dusts for chemical analy ses* It consisted of a small one half horsepower United St& as Bureau of Hines approved suction motor set, connected to a paper filter by a two-inch diameter smooth ball hose. | The paper was enclosed in a holder which was elevated to j breathing level height by a tripod. The apparatus was com-j pletely portable and was used wherever electric power was j 142 available* In operation, duat-laden air is drawn Into the filter* She dust ia retained and the clean air passed on through to the fan. This is your fan motor set; this ia your hosej this is your filter paper holder. We just set it on an ordinary engineer's tripod so that we can carry it around at the same time keep it up in the air, and the filter paper holder section is here. It was a simple metal affair* It had a screw cap on it and the filter paper was held in position there tightly* How, we're not sure about the efficiency of col lection of this device, although we know it's very high. Through experience, we have learned, for example, fch&t we can run this thing all day in a coal sine, collection a -- collect a deposition on the filter which would be on thi* side, heavy enough to completely fill up all the cleats, and yet when we take the filter paper off, the back of the filter - the color of the back of the filter hasn't changed at all. that Is if any particles did pass through, there were very few of them, so that the paper must be an effic- j I lent collecting device* j The device was employed for collecting the air-- j borne dusts from coal face operations, from workings in rock and during the coal train haulage. Figure two illustrates j a typical section through a coal formation of two of the j mines surveyed# This particular bed was the deepest of three coal seems which were being mined at the time in the same coal field or coal measure. In other words, three operators, three other beds had different elevations in the same geographical area and were being mined; this just i: happened to be the deepest# it!; The roof above the coal bed was a mass of sand ti stone deposits separated from the coal by a narrow layer of top slate. Lying beneath the coal were deposits of other I! sediments as coal slate, fire clay and sandstone. In ad S dition the coal bed itself contained several other sedi mentary depositions, termed locally as binder -iearns. This is your main a andatone area roof. We have a top slate layer here, some mines this wasn't present and others it I was present. Some places, geographically, wo called it - in seme places it was called broceli. This is your coal face or coal bed. Here are ifll other sedimentary depositions within the coal face itself | or rather inclusions of sedimentary materials. Actually* while we const dor that this is mined as a single coal bed, j actually, we have one, two, three, four ioal beds repre- | senting different sedimentary cycles of coal formation, be- j cause each one of these binder seams was lain down after th* lower coal seam was deposited. In the other coal mine study, the respective coal seams were similarly enclosed by sedimentary deposits of varying thickness and minerological composition. In seme coal beds, tbe binder seams were less prominent; in others, however, the coal seams included, in addition, deposits of Golden Bright, again these local terms, and rock layers as il much as eight layers in thickness, ij in the mine represented by this coal fkco, bulk P samples of each of the various rock horizons, both anclos- I ing the coal and included .n the seam, were taken for chea-j |! ical analyses* All contained free silica* j : In the sandstone, the analysis, the average analy4 i jj sis of several samples showed it contained sixty-seven per cent free silica, the top slate twenty-one and a half, the j binder material which again was a sedimentary deposit, probably a shale material, contained forty percent free silica* The coal itself was taken very - quite a number of samples - and the average of these samples was only three ! tenths of one percent free silica. Coal slate and slate - i ' the two in this particular case were so intermixed that we !: :i couldn't separate them and the combined analysis, the con i' binad analysis showed thirty-one point one percent, the " firs clay 39.2 percent silica, the sandstone similar to that so all of these sedimentary depositions other than coal con- | tained appreciable amounts of free silica. j Chanel samples were obtained frc:.. acros the ' ... f 145* \ O !i entire coal face from the roof to bottom anc showed froe silica aiunploa ranking from 1.5 to 7.2 peroent. The average ii of thirty samples was 8.3 percent silica. Tho air-borne dust created by all operations during the complete day's shift was collected on filter paper. The free silica values of these samples, however, ranged from three tenths of one percent to seven tenths of one percent with an aver age of five tenths percent. ! | The ch&nel sample was simply a run or cut of the ii if roof of uniform else direotlj across from the t.p to the i ii bottom and collecting all the droppings that came out of that room and analysing those for silica. These results indicate that although silicious tutorials were associated with the coal bad, most of tho dusts created by the coal faoe operations origin&zed from tho coal itself. - We can see that pretty wall even though we do | have the silica-bearing materials here, the air-borne dust l: only contains half of one percent free silica. M Kay I have the next slido, please? To illustratej t-.-nia point, still further, table Two shows a comparison of the petrographic analyses of three different types of sampling ; obtained from the same coal face, A quartz content of the coal only in this particular case was a hundred to one per cent. A char <1 sample from the entire coal face showed three oarcent silica and a filter paper collection of axr-borne lfcA. dust from all coal operations revealed but three tenths of one percent silica. When this first sample was obtained, we Instructed the man that was doing the drilling with a drill, to drill into as clean a coal area as he possibly could and then we collected all the dust from the drilling and the quartz content of that dust was a hundred and one percent, -- rather* one hundredth of one percent. Undoubtedly, for the proper evaluation of th silica hazard in coal mining, analyses should be made of the air-borne dusts rather than of the parsnt materials. Dust conditions to which men are exposed for coal can be divided for study into three general cate gories t The dust divisions related to operations of the coal face, those existing in coal working sections which are adjacent to the coal face and those present in other areas of the mine, through which men most travel or in which general work is done. Hay we have the next slide, please? Table 1 shows the average concentration of dustiness associated with common coal face operations in six bituminous mines. 250 j samples are summarized in this table. One or the first j standards Tor permissible levels of dustiness for silica, ; applied in this country, judged that if In any given dust concentration less tnan five million particles per cubic , foot of silica were present, the condition was cor idered JM. oafs. Recently, the United States Conference of Industrial Hygienists have proposed that no permissible concentration i of any dust should be denser than fifty million particles , per cubic foot* Following this, the United States Bureau oi ; Mines suggested a maximum weighted average dust level for I coal mines of twenty million particles per cubic foot based J on a work shift exposure* | Now, the first standard has some experimental | basis* The other two, in part, are attempts to establish || standards of good practice* In mines No* 1, 2, 3 ij all the coal face operations where wet methods were used, ; tho dust conditions were probably with one exception, ccsn- j plied with, or they complied with all of the above stan- !i dards* That exception is this mine - this 9U-*0 f jure* j Theso dust counts are all in millions of particles with i the particles being all less than ten n csron per cubic j; foot, so this 9k0 figure, if it was properly weighted by || the time required to drill the five or si; holes in the fact !; which ordinarily was about a half an hour, it was m-obably j j; weighted against tho number of times that the man had to j j! drill these holes in an highu-hour shift, would probably | bQ iess than fifty million particles per cubic foot, , probably closer to that* No air-borne dust samples were collected in these first four mines. We collected bulk sample- but 114.8, not air-born. samples. Prom other observations, however, from a comparison of bulk samples from one, two, three and four mines, with five and six mines where we had air-borne sampling, the silica content was probably but slight-y higher than that reported in five or found in five and s _x. Now, dusty conditions were experienced In Mine Number Five and still higher dust conditions were found in Mine Six, even when using water* Based on silica content, however, the highest count taken was 3*3 million particles per cubic foot of quartz, that is even this figure of 6?2*3 million, with cutting dry. Mine Number six, that's total dust - the free silica count In that was only 3*3 million particles per cubic foot* In Mine five, and particularly Mine Six, the coal was much mors graclle, it was much more dry and gave r iss to more dust than did the coals of any of the other mines studied* These results Indicate that In most bituminous coal mines, dust conditions of good order can bo maintained*, In exceptional cases, however, additional precautions are required to prevent dust levels from approaching a silica j I hazard* j I You can see in this dust count, this dry cpsra-- j . i tlon of cutting want up two hundred million particles high-! er, that we would approach an equivalent of fifty - of fivej particles of silica present. We would be introducing 114-9. . silica hazard siBply iron, the silica which was present even though at low concentration. Table three, please. The next slide, please. Levels of dustiness at coal section operations other than those at the coal face are shown in Table 3. In Mines 1, 2 and 3 and 1+, in this case also Mine S, conditions were main tains d in good order;although there were - they were moderately high in Mine 6, the silica count was low. By shun wing car cycle, we mean that we went we travelled with the operator of this particular car. The car i ^ e l f represses a - looks like a large shallow pan on four wheels, and he travels from the loading station in the coal face to the dumping station into the mine cars through the - through the coal section itself, and our sample was taken during the course of this complete cycle. When the shuttle car arrives at the dumping station into the coal cars, the coal was unloaded. ( This particular operation gave rise to, in some iij -Aft- stances, to more dust than in other parts of the operation of the shuttle car cycle. You con see here 127.8 for that particular operation alone; xhat 127.8 is part of this 3 general air in the roadways was pretty clean although in Humber 6 mine, conditions were ordinarily dusty throughout,, and also dusty in the roadways. rm ,lease. Lust counts taken in intake gas supplies to the six mines showed consistently low values* It is in some of these airways that men are transported to and from their work places and whore coal i car haulage is done. In some of the mines, sand was used on the tracks to give the locomotives additional traction. Several air-borne dust samples were collected on j ! filter paper in these mines, from the position of the motor man during the course of an entire shift*s operation. The levels of total dust and of silica in each instance were within permissible limits. This (next slide) represents the area in the mine frequently travelled, where car haulage is done and the area of the mine where the work - where the workers spend possibly an hour or an hour and a half of his day just in the course of transportation. The next slide, please. Table five is a summary obtained by the United - obtained by the U. S. Bureau of Mines in sampling the roof blocks common to fifty-one coal mines in nine wastern states. It was presented by James Westfield at tha American Mining Congress meeting In X951. It shows that more th n ninety percent of the roof i blocks in these mines were sn&le and sandstone, averaging j 26.5 and 55 percent free silica respectively. These vai-a-a ; are In accord with the findings of our survey. ; Unquestionably, a definite silica hazard exists in coal mines when work is done in rocks other than coal* Shafts or inclined slope* are driven at time* which required penetration in the rock. In some mines, rock falls and falls of roof rock must be removed in tne course of opera tion. Roof folding is a new practice which necessitates the drilling of deep holes in rock. When such work is done dry, resulting dust levels are high. It has been demonstrated conclusively, however# in other rock mines and in tunnel work, that levels of per missible dustiness can be maintained by the proper use of water and ventilation. Some of the coal mine surveys follca this practice. Other mines, although they drill dry end work in rock dry, provide the men with filter respiratory equip- mnfc In conclusion, it must be remembered that these methods are in respect to modern day practices of mining. It can be applied only &a changes and practices remain es sentially unchanged. In any occupation, the occupational dust conditions to the exposed worker, the history of ths mine as well na the history of the man must be taken into consideration. Disease conditions may well be the end re sults of dust exposures which he has experienced previously^ , , Thank you. (Applause). BY DOCTOR DRINKER: W e will try to limit the discussion on this paper 15-2. to about five minutes, because we're a little bit behind time* I'd like to ask Mr. Urban one question* Are you both ered by the bits of paper interfering with those samples in petrographic analysis when you use that completed filter? BY MR. URBANi Ho, we have pretty good success with it and Doctor Durkan is here, I think, and can tell you about it* We have analyzed very small papers successfully* BY DOCTOR DRINKER t Are those the filters that are used in the Chem ical Warfare Service Mass classification, you get it from the M. Si A.? BY MR. URBAN t I'm not sure about that, get it from M* S. A* BY DOCTOR D5IRYBR: That's the type we use* B Y MR. URBAN; _ The only difficulty we had was trying to sample fields that were a little high in relative humidity, the paper getting wet, but where the humidity was leas than say ninety percent, we didn't have too much trouble* BY DOCTOR ERIK" ~Rt Doctor FIetcher? BY DOCTOR FLETCHER: I'd just like to ask one or two questions, raaka 1534. one or two comments on this most Interesting paper* First, as to the method you use for free silica analysis. We have recently in Great Britain, circulated a sample of dust arouE d about six laboratories, and using three methods of free silica analysis, and the answers ranged on the free samples of dust from about one percent to ten percent on the same sample of dust sent around to different laboratories, so I i f-Mnir the free silica figures are very significant in rai | lation to the method used, and also even to the individual 1 using the method* | Secondly# I notice you did petrographic analysis of air-borne dust* How, that has e' ded us so far. We have not been able to study inhalable dust under five microns ! in diameter by petrographic analysis so far* The petrolo- ! gist will go down to about tea, fifteen microns; below that, be says, 'Sorry, can't help you*. We hope we're getting ! soE&wh&re by a now method in which the particles are crushed i under the microscope, into a thin, sheet and we may be able j i! | 5; to identify them petrographic ally that way; we hope ao* ' ji Thirdly, I notice you took samples on filter paper; you apparently dispersed them to get your counts* Of course, the man doesn't do that. He breathes the dust in the air, and his own system anu his respiratory tracts takes the particles, and our view at the moment is that he doesn't inhale anything over a particle size with a terminal velocity equivalent to a particle of - a p W l e a l particle Of unit density about five microns diameter. How, of course, if you collect dust on a filter ana then dl.p.ra. It. you break up all the aggregate, and U,e aggregate. ... of oour.e, the big factor In the actual inblable du.t concentration In any c o l mine. X won dered what your view, were on that point. And, lastly, I see you quoted average duat con- venerations without nentionlng any standard areas. S. find that th. co-.ffici.nt variation of precipitate amounts. X quote from memory, i f . of th. order of fifty percent. Share 1. a collossal variation fro. moment to moment, and juet an average duat concentration taken regardle...to the moment at which the man Is working snd without refor.no. to the various - th. variability v. feel may be highly mlaleadlng. and I wondered whet your view, wore on that q u e a t - p BY HR. URBAKt Ixa sorry X didn't make myself clear. The dost counts that we made, the dust counts that we made were m>t on filter paper but we made them with the standard Uni j States Bureau of Mines Light Field count. That is we actually sampled atmospheres and counted particles lass ! than ten microns. The filter paper collection was simply ; to collect air-borne dust. 1 How, it's true that, petrographically* we can not. sea, that is we can not analyze petrographioally, partiolea lower than fire microna. In our case at the laboratory, we employed three men. We used topography, chemistry and in dex, and X-ray defraetion combined to give us some idea of the mineralogical components of the due t. We had done the air-borne samples by petrography, so we could get our other mineralogical components, and their action, like calciiai, magnesium, iron. The quarts in that table was done chaai- cally. Now, the reported average counts for several cf thesei One was a very practical one* If we put the ranges j on that table, there Just would be so many figures we coudll not recognize the table, and certainly we did find variations as much as fifty percent from one count to another in ths series, but we did report the average because we studied the series* The average looked fair and we reported the ;i average* BY DOCTOR DRINKER t W e 're doing petrographic analysis, Doctor Fletcher, on particles that are well under five microns* The only \ one you've got is past history. It seems to me iz'a per- j fectly analogous to what you demand in radiological analy- j i sis. Ycu won't give a positive diagnosis of silicosis un- j less you know the man's history. : Well, I don't see - this seems to me perfectly : 156. analogous, if you know the past history of the dust and knew it accurately, you can do things petrographic ally that you j can't possibly do if you come into an unknown,and following ! that argument out, it's common knowledge now that a number : of our laboratories in the United States do do petrographic analysis on dust well below five microns They wouldn't teach you that in a course in petrography, but it's being j \ done. I asked him that designedly, that question about the interference of the fibers on the filter, because Bris coe Matthews and your other pels have said that you can't do it with those. My point is that the nuabapa of those fibers are so trivial that they're not of any conse quence, but I *m sure that the Americans Don't pro. jas that their accuracy in these determinations In any way is remark- | able, and we have just as bad troubles on the big ranges of i concentration as you do. 1 The next paper is by Doctor Fletcher on Radiologiy j cal Classifications. I! B Y DOCTOR F L S T C S S R | Mr. Chairman and Members of the Symposium ! i sorry that I should appear again so shortly. I hope J I'm j j that j there are not too many radicle-ists in the Symposium this j morning, and although I should like there to be in some ways, TAKHI FBCH PACffl 156, BX H3PBiBJ3BSB5 Mr. Chairman and Kasbars of th gyseposiusu I* sorry that I ehraild sppss? again so shortly. I bop that th*ra are not too assy radiologist in tb S^pesini tbi sosaing, end altboo^ I resold 31be thars to ta in css trays, .zi^ j and that ia that I find that radiologists known as little 1 about radiographs of pneumoconiosis as general physicians | know about the clinical and physiological picture of pneumo- | coniosls# I Seven years ago, when X started my work in rela j ; tion to pneumoconiosis in South Wales, X consulted a very eminent radiologist in London and he told me that the radiological side of the pneumoconioses had boon completely worked out and there was no further cause to do any work in j ; that subject at all# And when I got down to South Wales, I ! j started studying literature# i Could I have the first slide, please? And this | is a brief summary of the sort of thing I found about the S systems of classification that had been widely used in rs5 1 at ion to coal miners, particular!' in various countries. I fhare was the original ILO classification with the three ij stages which were partly radiological and partly clinical; ji there* was the Miners South African Classification that seme ! il author* had attempted to apply to coal rainarB with all these elaborate classifications here, mostly based on the site of j : the operation; the American Public Health Service cl&asifi-j cation used in those excellent reports in the hard and soft,; ; coal miners, again with various elaborate subdivisions. j How, these ones here, and this side of th- diagram I know the real equivalents in these classifications,because JLS&l- weve dona actual readings of the same sets of films in the j different classifications with the people using them* and wej know some thing about the equivalents. Over here, the equivalents are a bit different. We have the French one, which is normal with a little sub group of normal, the pathologique normale* which is a rather nice bit of French compromise, the little sub division of normal, and the fibrotic F here, *Fibros modu-- laire*, and supernaturale, and these were based on the size of shadows. The Germans, in deference to them, I have simply - I have simplified what they actually do. They actually put in the Intermediate classifications of one and two, two I to three, between two and three, and they even have a sub division here, naught to one to one, and naught to one to one in between these two, and then the Silicosis Boards in Eng land have modified this original one hero, Genhardt, who wrote those, did the original survey work , In South <?ales I they had done an original classification of their own, us in a term retxculation, wnich I regard as an abomination, be-- jj causa it is being used by different authors to indicate anyi i! thing from a normal film up to the most advanced nodulatlon and then that was the situation, and we eventually worked out a now system of our own wnich I have indicated roughly here to __________ _______ ______ _______________________________ 1S9. Now, the three reasons why we wanted a new sys tern* I First or all, none of the existing systems recognized the basic distinction we wanted to make between radiographs that showed only generally discreet nodular shadows and those that had, in addition, local, coalescent or massive shadows* Our reason for wanting to make this distinction was largely based on Professor Goffe's work, as he made a very clear pathological distinction between what he called simple pneumoconiosis and massive fibrosis, and 1*11 show that in a moment* The second thing was that in our follow-up stud ies of radiographs of men progressing, we found that the progression of the disease in those with generalized dis- dreet shadows, was manifested always by an increase in the number and profusion of shadows end only in proportion by an increase in their size* Now, all the other classifications indicated progression by increase in size, ignoring increase in pro fur ion* Arid, the third reason was that we wanted to make our classification purely radiological* We didn't want to have any confusion with cl.uaieal symptoms which had appear-1 c * in some of the others* j ! The next slide, please, shows this basic dlstinc-j tion -- the radiology -- between coal deposits in uhe lung j-- 160. next slide -- and those with, in addition, large massive shadows, and that is the basic distinction that we make in our classification. Could I, just for one moment, have the first slide back again. I'm sorry to go out of order, but it just would help if we could have it back. Weil, now, we devised a system which has been published and which some of you know about and we advocated a similar system at the ILO Conference at - I say we did -- I advocated a similar sys tem at the ILO Conference in Sydney in 1950, and somehow or other, they suggested a system of classification that bears rather a rosemblance to the ons that we have been using. Later on, we thought that the just mere announce ment, by an International conference of a system of ciaseiI ficatlon that was a good one wouldn't do much to increase | international understanding. In any case, the ILO have not j| yet published the report of this Conference. Things go | siowly In Geneva. The Conference was over two years ago, I but nothing has a p p e n d y.t .tout it, ana w. wanted to bo l ublo to understand epidemiological results that worn being ? obtalnad by workers In ooal fields in tho north of franco ^ and in th. Ruhr in Germany, and we therefore, sent thou sets of films from our mines and asked them to send us sots cf films from their mines. We carried out readings in their classification i I __________________ ___.________________________________ 161. j I i' and our classification, and we undertook meetings to discuss j this and eventually, both in France and Germany, they have | agreed to use this type of classification for their work, but have introduced a small modification that they want to distinguish in the groups of simple pneumoconiosis, that I here the type of films with very fine capacities, moderate size and larger size, so as to retain something of the orig inal indication of size, but in a secondary role* Well, now, the actual classification used, con- j sista of a normal group, three subdivisions of discreet shadows* We originally had four; we have dropped the fourth now. Three are quite sufficient , and then they have four divisions of cases with massive shadows. , How, t next slide. Hare la a radiograph. Xt*s j almost impossible to demonstrate these things with lantern ! slides, but I have got quite a collection of films hare if j ! " ' J anybody would l:!s* to coru and see come of the original ; ; films afterwards, but in classification 1, we demand pres ; i ji ence of minute opacities, usually one millimeter to 1.5 !i millimeter diameter, in little clusters in at least two rib : spaces, each area occupying an area of one square contimrai-*r, In Cl .sificat'on 2 -- next slide -- we require that these opacities be distributed throughout both lung 'J fields, but they are usually spares at the periphery and up at the apex. 162. By Category 3, they hayeto 411 1UnS * d are nov proihse ^ ` g9n^ 1- d * periphery. I! ***** ls the b a sic c l e s s i f i - . , . , nd rlsht * to | pnetuaoconioeiB. but m a d d itio n w . do " ^ ,to P 1* format ty p e ., that i . ,, Bllod ^ " ,Mior n Germans o a l l i t wM=h . i s o begins r , ; : 1 1 7 * " ' " M, and tho P h .p ^ .a t . c a n i t sene other mcisent which does b e g l,, . i th ,, * * " *>*. '* ,t ** * . tip. o e ^ i : r : ; In -- =onlo.,.. m ^ opaoitlee occur 1,, pur. o u ltu , ^ tiss. sit 31143 - ^ tJP* ' " " * -- * . bed the o o c t e e y to a ,, W o e h a lr ... The 5, _ oal1 14 'PSnh.M ing i t " " * " * *" " R i o t e d on c e l l bUt T nodular Preach noh, " *" ***. t h l s ' p ^ r ' e r i o ' r 1* ' f f O P M t ' I On the next alid T_ , tyos off fHXihta. in ^' V.* *" T* n the8 otthherr otbaannd" tthja 1 " Poaately, .Hodulalre. m end modular. m Oeraan, aad we i,,d , " m l "^ - nujsber Indicating the 7 ^ simple pneumoconiosis, end this, cl course ^ ~~ -- * noeur 1,, m3,, ,,lth . ^ ro -ho have actually got Caseload silicosis. ^ Wlti ^ ^ ! ! ^ i b $ ^ i f ? i c ^ s ? ? ly -- w m c h lustily* the tern ` 163. Well, now, coming on from that -- next slide - we come to the beginning of what we call progressive, massive fibrosis, PMF, which the ILO calls pneumoconiosis, with ooalescent massive shadows where, in addition to the genera] condition, you have an area with larger opacities, amounting; to rather more in diameter than appear, and although, In many films, the radiograph also shows a definite mass. That is the beginning wnich we call PMF, to distinguish the cate*> gories from the numbers we use in simple pneumoconiosis. The next slide. These cases have the peculiar property that they tend to progress whether or not the man is exposed to further dust inhalation. Our simple pneumo coniosis, we aee progression from Category Ons to Two or Two to Three only under conditions of dust exposure where presumably further coal dusts are being laid down in the lung, but here is a radiograph of a man who leaves with a shadow, leaving the mine in 194-1. Hext slide. By 1943, he has now a sizeable mass of it here and another one beginning there -- (next slide) -- and in 1947, he has a very definite mass hare. Kota the next one. The next one -- may we have the next one -- this is 1947 with now a large mass in both Bides of the lung field, and we indicato these decreasing size of masses with! the letters B and C, B for shadows that extend only over J three anterior rib spaces, C if they extend over more than j 16U the three anterior rib spaces, just to give an indication of their size* That's not a very important distinction, i so far as we know* ii || And, lastly, we use the Category D -- next slide ; -- for those which, in addition to massive shadows, have i J gross distortion of the diaphragms, the mediastina here, | and with emphysema at the basis, which, as this radiograph shows, can be quite extreme in many of these cases. So, in summary now, -- next slide -- we have the classification slide which I have used both in Prance !i and Germany; that's why it's international - in which we ! have the normal films with naught and the French again jj wanted to retain some vestige of their pathologique which | we call X, which is a film which you can not put your hand i on our heart and say it's normal because there is something jj ii that suggests pneumoconiosis to you, because it might well l| H be something else,some 3ortofnon-specific fibrosis, i h ! jj emphysema or what have you, bronchitis; and so, if you like^ j: you can call it X. Ue regard it as pretty bad form in the it j. pneumoconioses to use X; we only do it when we're absolute ; j : ly forced to, because we just can't make up our minds, j , Then, ,;e coma on to simple pneumoconiosis, which j ' i ; is threecategoriesdepending chiefly on thediffusion of j 1 the opacities, on their diffusion up to the rib area, with j the pinheaa, micro-nodular, mostly put in for the consideration ,165. j of the French, and for description, but we don't regard these categories as having any great significance. Natural his tory, and the prognosis and everything else, of the pinhead, micro-nodular and nodular is similar# Then, we come to progressive fibrosis. A, B, C and D, depending on the size of the shadows, and eventually D, which you can't see on the table there which has distor tion# now, that is the classification, and. now X want to say one or two words to try and persuade you that it may be quite a good one# First of all, it is a purely radiological classification. It ia used by looking at the radiograph and without any further information at all,which is what a radlolog&cal classification should be# Secondly, the categories are based on studies of the progression of the disease, so that the earlier cate gories represent earlier stages in the natural development of the disease, than do the l&ter categories. I Thirdly, in Justification of our categories of simple pneumoconiosis, we have found ev' ;nce rfhich I shall show in my next valk on the epidemiological side, evidence that there ia a f< rly direct quantitative relationship tot*tiitssn fiaaounfc of dust &xposu^& to pi'oducd \ three categories# The ratio of oust exposure required to j produce Category Two is about twice that required to produce 166*1 Category One, and to produce Category Three is half as muoh again* The actual ratios are about six to ten to fifteen* So that these categories do represent a fairly direct quan titative relationship to the amount of dust inhaled* We want to confirm that by chemical analyses of the amount of dust in the lungs in these categories but we haven't yet had the results of that completed* With regard to the relationship to the underlying pathology, there is difficulty. We, as radiologists, on tti radiological side, think the difficulty lies on the patho logical side and the difficulty I referred to yesterday, anc. that is the difficulty of getting the pathologist to be qiaijtitative and to say Just how much abnormality there is in different lungs, but we have got Professor Goffe and his colleague, D. ter James, to classify a large manber of lung sections done by his technique, which we had radio graphed too under three systems, one according to the pro fusion of the opacities, and also according to the sever!',v of the focal emphysema* There is no relationship between our categories and the severity of focal emphysema, none* The profusion : of the opaci ties is not effected by the development of focal emphysema, but there is a relationship, a definitely rough relationship between our categories and the dust foci, unicn is some 'ndication of the amount of coal in the lunr. 167. Lastly, the relationship to disability is of great interest, but as Doctor Hugh--Jones is devoting his talk to that subject, I will leave it to him, and I will only say here that there is little relationship to dis ability here, but a very great justification of this dis tinction between siiaple and massive fibrosis, on disability grounds. Now, one point,I don't expect any of you could see any abnormality in that film I showed you of Category 1, Well, now, quite experienced radiologists in England and in this country, are having the privilege of discussing some films of ours with Doctor Eugene Pendergrass in Philadel phia, and he expressed a firm idea that films of Category 1 and 2 were absolutely normal and he could parallel them with films of any man walking the 3 tracts of Philadelphia, I tried to get him to look at these epecifio ocpacities which I thought justified the diagnosis. He a&id he was looking at them but even so we couldn't agree and so cither we were wrong or Philadelphia w&a much smokier and dustier than it looked when I was there, or he was wrong. Well, I was very worried about this and I was worried, too, about radiologists who said that they couldn't see any abnormality in our Category 1 and, as this Category is one which we have used extensively in our epidemiological work, it was of vital importance to sae whether it was true 168* or not, so what wo did was to collect 125 films of non miners, men who had had no significant dust exposure# Some of them were members of our own unit, but the majority were men working In a power station on non-dusty occupations where wo had a survey, so we got good films there. We mixed them up and ran them out with films of seventy-five miners of neighboring mines which had previously been read by readers A and B on survey, fifty of there being normal and twenty-five of them being category 1* Well, now, we thought we'd be clever and not only read category naught, one, two, but we thought we'd put in an e xtra category naught, with a cross in it, to indicate that although we thought it wasn't quite category one, to indicate that the film showed as if it was a miner >2; film, because we not only believed we could read category one, but something earlier* So, that's what we asked the readers to do# The films were read, interestingly, by four read ers, A, B, C and D, and then read together by A and B, and by C D, and finally those films, on which we differod, were read in consultation by all four together, and here erb i the results for the non-miners and the miners# ; In the non-miner3, A and B -- miners, first of ! Bl [ were rather cautious under these experimental con- j ditions . They didn't want to show they had been reading ; one wrongly and you will sea or the twenty-five films, they read aa one - they read ten as one; now, I pushed them down to normal miner and non-miner# In so doing, they didn't read any pneumoconiosis in the non-miners and only read one case as showing, looking like a miner, but not being category 1# C and D was myseir and Doctor Gilson# We were more courageous and we read up a little bit; we read thirty eight out of these films as showing Category 1, one as 2, and about the same number, about thirty-sir. coming in the normal group, but in so doing, we had read four of the non miners aa having Category 1, four of tha 125# and nine as being suspicious# When the four of us met together to try and straighten this out, we pretty ti. .1 hit off the original level of reading the miners' films and we never once agreed that there was evidence of pneumoconiosis# I asked that A and B try and re-read these films using their normal sur vey technique# Here they were put off by the danger of reading things that they were frightened about and they did try and read them exactly as they read the survey films, j and they very nearly hit off the same level as on the sur- | vey and they never once read Category 1 in a non-miner# j They weren't attempting, in that case, to read the sus- j i picious# ; Well, I conclude from that, that ax any rate, we i 170. can distinguish our Category 1 and that it does occur only Jl very rarely in non-miners, and there only when we're over-- ; reading. When wa're reading as we normally do, a Category l> 1 is a thing which is sufficiently rare in a normal not to j! have occurred in this group of 125 non-miners. Jhst the I same, the sort of danger of less specific reading, I did j, send these films to two Germans who agreed strongly on this abnormality and you will see they read on the miners, and nc less than twenty and twenty-two in the aon-miners, as be ginning silicosis. !i * think this type of experiment, mixing up j completely normal films with films of men exposed to dust, is a completely salutory experiment. I recommend it to anybody who is engaged in this sort of work. Cue small point of interest, what with these oasei that C and D, Doctor Gilson and I, read as showing seme abncviaality. I was interested to know if it had any relation to Age .So I have Just plotted it out In relation to age.You j| see that there is a very clear relationship between age and f thls abnormality, and I believe that it is possible that ! th3ss old- aen S8d forty-five to fifty had, in fact, been j: | i -3xpo3d to a certain a mount of dust and smoke in and around j Cardiff, and that what we were reading as early oneuiaocon-- I iosis, may hs.v8 been the earliest signs of dust accumulat-- j lng in their lungs with age. I Ill- What is most Important is that even our overroad- ! ing of Category 1 never occurred in a man under thirty, and most of our active epidemiological work is concerned with men in that age group, so that I am quite satisfied that our Category 1 is an ation of dust in the and nearly always so abnormality attributable to the inhali j - at least in the younger age group, !i even in the older age groups, Hext, I Just want to talk very quickly about the j n l question of observation which has boon pioneered in this j i country in relation to tuberculosis, but I think we have j pioneered it in our country in relation to pneumoconiosis# j [ The first experiment we did was to gat 102 films of miners j ranging from normal to modulation in the original elassifi- ; 3 J cation. We asked ten experts to classify thorn into normal, j j] early, definite, certifiable pneumoconiosis, and nodulation# !j | i We found that, of these ten experienced observers^ | in thirty films, opinions ranged from one observer to the j I! i || other, from one to four or two to five, that is one quoted i jj normal, anothercertifiablepneuxaocbniosia, another nodula-; !! ` ji tlon. Forshattering results, I tookihat up toa very . |j eminent radiologist in London, He sell none of them were < !' radiologists. He said he and another radiologis t would | i agree a hundred percent on those films. The silly ass tried it, and the difference between them was greater than between all ten, so -- this is very important ~ tha number related as showing certifiable pneumoconiosis by these various observers, varied. One showed that four of 102 films snowed enough pneumoconiosis for certification; another said that 29 were -- I mean normal. The number certifiable ranged from 9 to >3. These ware experienced observers. The average consiatsnoy-each observer read the film twice -- was sixty percent; sixty percent of the films the observer did give the name opinion on the two occasions; the record was eighty-four. The other thing was undsr-expoeed films. Same of the films were classified higher than the hard films. V'eil( now, we have done a great deal of work on this subject and we have attempted to improve this situation, first of all, by accurate definitions of the categories in words; second ly, by netting up standard films exemplifying the cate gories, so instead of just putting a film up and saying, well, that looks like Category 2, you put up aothor film J alongside which has been agreed to be Catogory 2 and see if it looks the same and, thirdly, we have &c.opted the method of r:'ding shown to be so valuable by Duorshonn and his colleagues, of duplicate reading. Every film on our surveyj is read on two different occasions without any knowledge on| the two occasions what the previous reading was and any ! film on which two opinions differ is given a third casting | vote to get the final category. i 173. The next 3lide just snows -- no, we'll skip this one, I think this is just showing the errors in relation to the diagnosis of pure math in this international set-up. We 'llskip that one. How, this is our latest result of our readers k and B who do all our survey reading showing that first reading of five hundred f U n s taken at random from a largo survey of five thousand and their second reading here, and any film which was read normal on the two occasions nevjr geos to a third reading, but if no two agree on two reading we have a third deciding reading, and you can note the lack /-'I of divergence of opinion, which :.3 relative^small. Lastly, on the question of understanding, I have told you that we have been taking films around in France and Germany to get them read and here is at loastthe result of ISO films which we sent out, which we classified as thir ty in Category 1} thirty-two; thirty - three, and we sent them to them and put them into the international, classifi i j cation, and into the German class iflotion as presently used, and you will see that while there is difference In the minds of the observers here, there is, on the wnole, agreement. If they were to have classified that set of films and given us a prevalence of pneumoconiosis based on that classification, It would have been v*ry similar to | the prevalence that we would have found if we had read those We could understand their statistics, but if they films j, did It in their own classification, there was soma agreement; fj j! between the categories here. You will see that our Category l; B films are pretty evenly distributed, and what we call || Category A were distributed through the whole range* It ji | would have been very difficult for us to have any accurate | translation of that sort of classification into ours, even j if we had known what the results of this experiment were f; | going to be* At the present, tne existence of different seta |j or systems of classification in the different countires cf | the world, and the different centers, militates very sor- | lously against scientific understanding of epidemiological | work* This system of classification has now been adopted | pretty well uniformly throughout Great Britain. As I said, |i | it Is being adopted in France and in Germany* A conference is being held in Paris to further Its adoption in France, j next - the end of this week, on this Saturday, and I think j * * tMs h" for so" * = . t. |! start being active in this field and carry on this sort of i, j j! work we have bean doing on our own, by getting sets of filed i i sent around to the various centers where work of this kind | Is b ng dona so that we can see what the relationship be- j tween different forms of classification is, and If possible^ obtain the consent of the different centers in this part of: the globe, to use a classificatic - sinilar to that which we i US*. we are using, not identical, because I have no doubt that you will have a great contribution to make in suggesting valuable modifications, but at least that we should adhere to using a uniform system so that we can know what youre talking about and you can understand what we're talking about in our radiological work. (Applause). BY DOCTOR D R IN KER : Any discussion of this paper? Doctor Hich&rds? BY DOCTOR RIC: IRD3: ' ' I don't think we're too far apart. I think X could understand Doctor Fletcher aa he went along with this, very well, and I don't think I have anything particularly tJ add* BY DOCTOR O R E K S T E Ig * Mr. Chairman, I would just like to pay a tribute to Doctor Fletcher*s work from the point of view of the tactical worker in his field. To many of you, this may aWB to be a supererogation of trying to establish a whole lot of categories, but it is a matter of the greatest impor tance that there shouldbe u understanding in this matter, j not only from the point of view of epidemiological surrey ! but from the point of view of such countries where coznpansaj tion is based on stages ox' the disease and is not true to j form simply because a man nas pneumoconiosis. Ho receives I i ,,-?rJialn amount; if he has pneumoconiosis in a certain stage, 176 and a certain amount for a larger stage and so on, and be cause of that point of view and because of the groat damage that was done to the compensation question, the certifica tion question by the 1930 adoption of that one, two and three which you saw on the right-hand side of the scale, when an attempt was made to correlate the capacity, that is to say compensation, to stages of radiographic appear ance, now, a lot of good has been done by Doctor Fletcher in his endeavors in this way in particular, where he demon strated this at great length and 1*11 never forgot the night we spent in a small office somewhere up on the top floor of a Sydney building, threshing out this question* I also would like to pay & tribute to the objec tive work which he carried out in trying to discover the eri rors of his own interpretation and of others' interpreta tions* A lot has been said by radiologists, if wo have long enough experience and enough correlation with post mortem findings, we can classify with great ease* That's quite untrue* Thsy can not, and a lot more work will have to be done to make that clear* I merely want to say this, Hr, Chairman so that somebody who has to work in this fisld would speak for the j great benefit this work has conferred on the knowledge of jf pneumoconiosis * j BY DOCTOR D R IN K ER : ' 177. Thank you, Doctor# ! BY DOCTOR VOKWALDt Mr. Chairman, I should like to Join Doctor Oren- stein in his tribute to Doctor Fletoher and we here are in deed fortunate to have him with us and to hear what he has to say. I don't think that we're too far apart. Of course, there is divergence of opinion with respect to Category 1 and Category 2. That is whero we find the greatest differ ence. Doctor Fletcher, I know, ia keenly aware of the technical qualities of the film. He hasn't mentioned itj perhaps he will, the necessity for having good films of good technical quality in order to classify these films. Then, I should also like to ask Doctor Fletcher one ques tion, dooa his classification pertain only to the coal miners' lung, to the coal worker, or does his classification pertain to all of pneumoconiosis? EY DOCTOR DBIKlDBt Will you answer that, Doctor Fletcher? BY DOCTOR FLSTCISP.: Thank you very much indeed, Doctor Vcrwald;* raising these two points. I am afraid I was getting behindi time and I didn't have time but, of course, the technique ! of the radiograph is of the greatest importance , We have shown that the average of category given by ten obs< rvers 178# II to one film* or films of the same man taken on the same day, under-exposed and over-exposed, the average opinion may shift by one and a half catsgoriea easily, and it is absol utely essential to have really good technique and we have de voted a great deal of attention to that point in our own radiographic work# j We have now, in our mobile unit, not only an auto matic exposure control mechanism which Seaman's in Germany have devised for their automatic, which is quite remarkable in the way in which it enables uniform exposure to b. obtain ed of men of various chest thicknesses and with variations in main supply, but we now L,ve also an automatic processing unit which puts the films through at exactly the right time end temperature and in that way, we have been able to reduco ths master or percentage of films that we have to reject on our survey as technically satisfactory from about forty per cent right down to two percent# About the width of application of this classifi cation it has been worked out on coal miners and this work has been done on coal miners, which is the big subject r--- ; lem we nave in Great Britain, but I think that in principal, it is applicable to all the world's pneumoconioses which ; manifest themselves in discreet capacities going througnout the channels, t.a; is to say coal pn unoconiosis, what Doctor Sander was calling sidero-silicosis, silicosis and so on. i 179. I think the same principals can be applied* The members of the Silicosis Boards in Great Britain who see men from all industries, tell me that they find this method of classification valid for at least ninety- five percent of all the cases they see. There are the odd cases which you'll say, I'm sorry we just can't fit this in, you've got to put it down as unclassified. KV DOCTOR RICHARDS: Mr. Chairman, I think while we're discussing this problem of terminology, I'd like you to call on Doctor Johnston, from a clinical standpoint to say a word to you. BY DOCTOR JOHESTONl I have nothing to add. I just think that Doctor I Fletcher, in all the arguments yesterday, Doctor Fletcher | has probably established Doctor Sander's point that every- i body haa pneumoconiosis, the classifications one or two; i von the farmers I*m certain we'll sea, that in farmers who | ! live in impure air all their life, so everybody Erast h r t j ji pneumoconiosis# I |; gY_ DOCTOR DEIIIKSRi j There are a fair number of persons in this room ! who ana not good Roentgenologists then, and there is one ; J definitely of that number I 'd like to ask a layman's kind ! : of a question. I have been steeped in the doctrine started, i pankos and Sampson and right on down to the present experts, that these radiological pictures differ enormously with the 1 !' : 1 geology to which these men are exposed and presumably, i Doctor Fletcher's interests are largely in the Welch coal j ' fields. How does this classification apply to say our hard; I rock miners in the Missouri area, Pen argrasa certainly j ; must have brought that up in talking with you. | EY DOCTOR F L E T C r^R : | I think that the classification would apply ccsn- l pletely, but that our category 1 and 2 are a little earlier S| than Doctor Pendergrass would recognize. One of the dlffi- j n ' | cultiaa is with these very early abnormalitios, you have got ! to study the film extremely closely. We say ten inches is j i the right distance from the observer to the film. A great- j er distance than that you just can *t see those early changes j and I put up that film, that slide of the results of dis- i tlnguishing normals from those category 1, to show that if ! ! |i you do that, you can distinguish and all I can say to Doe Lor i! I ;; Johnston is that if you will get these films of these farm-! !, ers and send us a group, we will mix them up with some rain- j ( ! 1 srs and get some readers who don't know win we've dona to j read them, and I'll bethe'll find that theminers havegot; !; i ' more dustin taeir lungs andhave got ahigherproportion j 1 of Category 1 abnormality than have his farmers. 1 If, on the other hanc., hi3 farmers have got a groat deal of Category 1 abnormality, all right, I agree with him, 151^ they roust have some pneumoconiosis, and Doctor Lanza, I think,w ould agree too tnat it might be called occupational* BY DO..C....T...O....R.... .VOR.WALD: Well, Doctor Fletcher, there is no way in which J ,| Doctor Johnston can win, is there? BY DOCTOR F LE T C H E R t Yes, yes, he can, because we can get a third group of real -- in our country, there is very little dust in farming; in fact, none at all, and we could get a group such as these power station workers who also are not psrhapss i a dusty occupation as your farmers# I don't know. I have j heard about the Dust Bowl, but I don't know how dusty this | I is, this occupation of farming over here, but we could cer tainly get a group of true normals in agricultural workers in our country or in office workers in Sew York; looked to me as if th e atmosphere was pretty clear t h o r e , and we could s a y these are normals. I f we d ia g n o s e a b n o r m a lit y I n th em , then c l e a r l y t h i s C a t e g o r y 1 K s - r e t a l k i n g _ocrut i s a b s o l u te n o n se n s e in te rm s o f c o a l w o r k e r s pnauriioccaiiosis. BY DOCTOR JOffiTSTON: j P h il, I don' t want to la b o r th is p o in t; I happen j to have a d a u gh te r who has liv e d in C a lif o r n ia a l l lia r l i f e i She has n e ver been on a farm , never done any work o f any j k in d , there i s no bitum inovn c o a l in C a lif o r n ia . I can I vouch fo r t h a t . She does h ave , how ever, s one m arkedness th a t DR. SARDSU I dae*t say that everybody haa poeuaoconioeie which 1. visualised by the X-ray. Va all have eoaa pnruwoconioais, ty strict definition, hit not sscsefcfaisf visualised by X-ray. One can have a lot of anthraeeiie plgsaafcatioB and 8till have a perfectly noiaal cheat fllau Ve are deeply indebted to Dr. Platci&r for thle precise classification and I ce bo reason d y w m ' t adopt it for Manat every industry in thi. coutry. Even the OlatcMMous earth ease, can go into categories A, S/f anA Cjt they Rise categories 1, 2, and 3 because the shadow are never nodular. I sea no reason why * eaoH use the eltoHO^ t ^ ^ b r ^ O a o a t env duatyj^duetry in tblo country, $& FLSZQimu I wiifch to ^ke"!t clear that coraal individuals in Great Britain vhcm * h*1? *n" * lBW* 4o not shew the alaoraality ve classify as category 1, CKCspt psraap* 1 or 2 par cant of :.raoaa elder than 50 years. I m Quite > vtoaod that this aisjoraslity which ve are classifying is a specific change pWMS8ert ** dust* 1 * * that the Odd esse of c c r a U a d a or nwwip.cific f&bcL eaa* aisle it but that is cniaportaai frea the aturtpelat of indstri2. mdi84a** * 5-da*t w n y if ve nahe a nisfcska el-out the odd dis*ce which os i l i i slllioa, but this condition is specially assorted with the dsvel^mnt of duet retention in the Inns, fc# is jshown by tee eosl alasr, 2s l&torested in Dr. andr atataasat that sons persona say afelp cat*- SarJ^s i 2, sad 3. i believe that happen# to g-rfcfcsry ta>rfc*re in asr country ssd I huv* smmo fllsaa supporting this belief, DR. TOisauj* If you ossify la category 1 CA individual who has had got* respiratory difficulty, arc you ready to coapuooate M a for the inhalation ef o might be classified under two of your films* Now, I don't know how, what we do about such people Vfe can get into a hobby classification or a work classifi cation and still they show this little stuff* Now, Im still getting back that we must adopt a point if we're going to go ahead with your classification, to get back to Doctor E ra se tt Sander here that everybody haa pneumoconiosis * BY DOCTOR D R IN K E R * Doctor Sander? BY DOCTOR S A MP E R : Id like to clarify that, I don't say that every one has pneumoconiosis which is visualised by X-ray, s all have some pneumoconiosis by strict definition, but not visualized by X-ray* You can have, I'm satisfied, you can have a lot of anthracotic pigmentation and still have a per fectly normal chest film, I think we owe Doctor Fie tcber a great debt of gratitude for this precise class1' nation, I see no raason why we can't adopt it for almost avery industry in this country, Z .an the diatheriaaeious earth can go into Category A, E and C; they miss Categories 1, 2 and j i 3, t cause they never are nodular, and I don't see any ; reason wny we can't use It Tor Rlmost any ana every fiustty , industry In this c o u n t r y ^ - W i t ' BY DOCTOR D R IN F E R : i Doctor Fletcherf BY DOCTOR FLETCHERt I do warn to bo absolutely clear about one point and that ia th a : uc. ,tl individuals in Great Britain, that we have examined, do not show the abnormality which we clas^ ify as Category 1, except perhaps in one or two percent of those over the age of fifty* Now, I want to make that absolutely clear. I am quite convinced that this abnormality that weirs classify ing here as a specific change produced by dust. I w o n 't say that the odd cose of sarcoidosis or non-specific fibro sis, dermatosis, God knows what, can't mimic it, but that*a absolutely important from the pcint of view of industrial medicine* The odd disease which effects one- in a million of the population, we needn't worry about if we make mistakes there, but this condition is specifically for - as I 'm con vinced by our experiments, for the development of dust re tention ir; the lungs as shown by coal miners* I 'm very ir t e r e s ted in D octor Sander sa y in g th a t some p e o p le may s k ip C a te g o ry 1 , 2 o r 3 . I t h in k t h a t ! happens to the p o tte ry w orkers in our c o u n try , I have seen j t h e r e ,' w hich, show a shadow i n w h ic h th e b a c k g r o u n d ; j snowed no pneum oconiosis a t a l l , and I th in k th a t can h a p - | pen, bt z I th in , the p r in c ip a ls can be a p p lie d , and I ac ; w ant to make i t r i t e c le a r , and I t h in k p e rh a p s some o f the lSiu slides I shall show you on the epidemiology of the disease, will persuade you that this condition does develop in rela tion to dust exposure# BY DOCTOR VORWALDt I should like merely to ask one more question and that is, Doctor Fletcher, you have cln-sified now an individual as belonging to Category 1, had he had some respiratory disability. Are you ready to compensate him for inhalation of dust? B Y DOCTOR F L E T C H E R : I have the good fortune to be a research worker not concerned with compensation, and it's entirely a ques tion of the legislative definition. The practice of the medical boards in our countary at the moment is not to recog nize anything lass than our Category 2. I^y own personal view is that if a man has worked in a coal min3 and shows respiratory disability and has any evidence of dust reten tion, Category 1, it would be fairer to las the scales in his favor and give him the benefit. of the doubt and say that that disability could be due to pneumoconiosis, but I think that what Doctor Hugh-Jones will say this afternoon j may throw a little further light on that problem. BY DOCTOR JOHKSTOH: Doctor Fletcher, while you're still there, do you have any figures on your present employment classification? 165. BY DOCTOR FLETCHERI I hang my head in shame and say that although we have been agitating in o u p units for information, for four or five years now, for pre-employment and regular exaaina- i tions of coal miners, they have not yet taken place in Great Britain, but in those films I showed you of non-mlnars, soms of those might have been applicants for coal miners and all I can say is we did not diagnose Category 1 in any man even when we were reading rather generally, we didn't diagnose it in any man under the age of thirty-five. BY DOCTOR DRINKER: The next paper is by Doctor Yorwald on the path ology of Coal Miners Pneumoconiosis, Doctor Vorwald, BY DOCTOR VORWALDt Mr, Chairman, Ladies and Gentlemen, at the onset, I wish to say that we, in planning for this day's session, made every effort to bring Doctor Goffa from England, As you know, Doctor Goffe i3 Professor of Pathology and Bactcjriology at the Welch National School of Medicine in Wales : and he has had perhaps more experience with the pathology of pulmonary changes in coal workers than any man, and it j is unfortunate that he could not be with us, I Now, in a general way, our concepts of the change* in the 1 Lings of coal workers which have come to us iire in j | the Saranac Laboratory for study, conform in general with ; TAKEN FBGM PASS 135 L. yc^Ai^x Kr. Chalisao, LeAi.se and Gentleaen, at the onset, I wieh to aay that we, in planning for this day*a eeaaion, sade every effort to bring Doctor Goff fro* England. As you know, Doctor Goff is Professor of Pathology and Bacteriology at the Haleb Sationnl School of KadieSna in aloo and he haa had psrfesapa sore experience with the pathology of puXsor.sry chanj?s in coal .srScers than Euy nan, and it is uaforteat# that he could not ts with ua. low, la a general way, our eoaeepts of the changes in the Itrgsa f cel vorksra which have etas to ua here in tha Sarsaaae la-boratcry for study, eonfeza in general with the concepts expressed by Doctor Soffe* In some Instances* j however* there is divergence or views wnich I hasten to say is occasioned perhaps by the fact that our study of lungs of coal workers has been limited to relatively few cases* In addition, it is possible that the conditions of exposure experienced by coal workers in ttiis country are different fro conditions In Wales* Furthermore, the problems pertaining the in halation of coal dust are indeed complex* Now, that com plexity may be more fully appreciated should an attempt be nada to answer the question as to what is coal dust, and then may I have the first slide* Now, this slide, taxon from a publication by Parkers in Coal Science, by rector Banlon, Director of Re search Laboratories, the Britlfc.. Coal Research Association, her Doctor Banion has tabulated sane of the various rare I elements In coal ashos* ) Now, the data, as we see them hare, are expressed in grams per ton or parts per million* To give an approxi-; mate idea of the concentration factor, comparison may be j ' . i made with the average amount of the same element found in j the oridnary rocks of the eartn's surface as well use thi3i facte -* As for Arsenic, As, arsenic is one thousand six ; hundred times - one thousand, sis hundred times nore concen trated in the ash of certain ccals than in the average rocks 187 of the earth's surface, so we can also go through the llst-i i ing of the otner elements, beryllium, germanium, lead, nickel, platinum, zinc, zerconium, and you can multiply, you can see the factor, the ooncentratio n of those subatances in coal ash* How, it is possible that some of these substances exist, per se, in coal in the dust breathed by these indi viduals and it is also known that some of these substance* produce damage to the lungs* jn attempting to define what is coal dust nox slide -- the problem becomes even more complicated should we examine the so-called coal tree, and here one visualisos the production obtained from co&l by carbonisation. How, many of these products may exert their effect when deal dust becomes deposited in the lung* I am not too clear about this, but 1 merely present it to give expos to tho t possibilities at least that some of the complicated features as we have seen them, pertaining to the inhalation, deposi-j tion of coal gvt in the lung, may be related in some way to all these products which are derived from coal. j How, what are the changes that occur in the lungs | j of some coal workers expo d to coal dust? This is the j chest Roentgenogram of a 38-year old, I mean of a f i f t y - : \ year old whits male, who has worked for 30 years as a motor*- man in a bituminous mine. Now, his medical history was i . Irrelevant except for two years prior to death when this j individual suffered from dyspnea, from exertion, I mean, es pecially on exertion, and from productive cough* Further more, he had clinically manifest arterial sclerosis, which - and ultimately developed multiple infacts in the lung and brain and he died In coma* The X^rays, as you see hare, the lung markings are slightly exaggerated. Thera is a primary complex, as you see here, in the right lung. Thera is no definite Roentgenographic evidence of change, comparable at least with a diagnosis of silicosis. The grof ^ section of this lung exhibits diffuse pigmentation, slight focal emphysema, as you see, rather coarse in type, some focal emphysema in tha lower lobe of this lung which is of the right side. The lymph nodes are small, but they are slightly pigmented, and this is the section of this lung and it happens to b the left upper lobe, and vre find that there is focal deposition of dust scattered everywhere throughout the lung. Further more, there ia also deposition along the vascular fronts which gives rise to what we call a linear deposition* Also one sees the dust deposited, in tue tissue immediately bcloWj th-" pleura. Furthermore, one can see at least the dispor- j portion between the size of the alveolar spaces which we | identify as the anatomical evidence of emphysema, also note| the tracho-bronchial lymph nones which are only slightly j 189. enlarged and plgmontod. This is from the right upper lung, right upper lohe. Now, in addition to having the focal deposition of dust, the linear deposition of dust along the vascular tracts, we also have a large area of deposition of dust and in addition, the emphysema in this instance is quite ob vious, occupying one small portion of this lobe, but it is aleo apparent in the mid-portions of the lung and quite well scattered throughout the whole pulmonary tissue. The next slide, this is from the right lower lobej I am merely showing you the different sections from differ ent portions of the lobes of the lung so that you might have opportunity to compare what we see in the actual with the changes visualized in the Roentgenogram. j Again, this does not differ muoh from the section? of other lobes, focal deposition, linear deposition follow-l ing the vascular tracts, evidence of anatomical forms of atj least coarse emphysema. The next slide. How. if we examine tk s lung microscopically, we find that many of the vascular trunks aj,e surrounded by a small amount of connective tissue which is | readily seen in sections named specifically for connective j tissue. Here we find no evident deposition of dust arourd j this vascular trunk. As you perhaps know, following the | de .ition of dust in the lung, that dust is taken up by j n!90 phagocytes; it is mobilised. Those jfriagocytes, laden with dust, find their way ultimately, chat soma of those phago cytes, ultimately into the lymphatics about the vascular trunks, but this is a normal vascular trunk seen in the section of this lung* The next slide. And then, we examine other vas cular trunks and we find that in some instances, there is deposition of this black pigment, and there is a slight, very slight increase in the collagen that has been formed* you can see by this connecting tissue* The next slide* And if we examine the lymph nods | j of this man who, as you will recall, was fifty years of agejj . I ! and worked for thirty-eight years as a k q t o m a n in a bitum- j inous mine, we find dust which has been drained from the lung to the tracheobronchial lymph node, yet, there is no evident significant response to that dust which has beccse j ! deposited in thenode. ! !i Ve thus - this case demonstrates that long oecu- ; I! 1 ji nation in a coal mine as a motorman dees not demand the prod- f 6nce of large amounts of dust in the lung nor does that | j occupation demand the presence of significant pulmonary ' changes due to theinhalation of dust* j next case, some cases exhibit changes as seon i in this case, as seen cases with classical silicosis, com- ; plicated also by tuberculosis. This is the case, the chest' Reontgonogrem of a fifty-year old colored raanj occupational history, worked underground for twenty-eight years as a ooal loader for eleven years, as a rock helper and reck helpman f thirteen years, as a truck helper for four years* My X --ray on the right side, we see scattorec. throughout the entire lung field, areas of increased densi ty, and there is also a fan-shaped, area of consolidation, as you see in the upper third of the lung, 'within the region; that region there is also an area of relative rarifactlon* On the lft side, there are scattered throughout, small areas of increased density* The next slids. The section of this lung, this happens to be fcha right upper lobe, exhibits sc&ttarsd nodular lesions throughout all of the lung tissue* They are quite wall defined, but yet not as defined as is the case with the classical nodular silicosis, in that the bor- ; dare of these lesions are iiussrralar, and if we examine many , of them, we find that they are scattered in shape, with flnger-llka projections into the adjoining alveolar walls* The next slids. And, if we examine many of these 1 nodular lesions, we find that they demonstrate the deposi tion cf collagen, arranged in typical fashion, which ia classical for the reaction to free crystalline silica. In addition, wa also find that the periphery of these nodules, is usually surrounded by a thick or thin collar, depending 192. upon the circurostanoes of exposure, of deep pigment, of black pigment* Furthermore, this pigment, and its associa ted slight reaction, deposition of collagen, extends into the adjacent alveolar walls* Examination of other lesions, ue could demonstrate fibrosis, actual fibrosis, of hazy fibrosis in this case, of this islanlzed fibrous tissue, which is similar to the change of scene in si'iicotics, com plicated by tuberculosis* Thus, under certain conditions in coal mining operations, or certRin coal mining operations are associated with the dissemination of dust, which, on inhalation invO the lung, produce silicotic reaction, and some such rouetiohs are also complicated by tuberculosis, as is present in this j case* This complication is more evident in the next case* j Hext slide* The gross section of this, the lung i of a driller in & bituminous mine. Ha was a driller for nine years, been .posed to high levt&s of free crystalline silica* Now, we see, first the nodular lesions, scattered throughout the lung* We see that they are studded in shape V see many of them on close Inspection, that they project into the a d j o M i n g alveolar walls. Ve see the evident emphysema which is at boat and coarse in type. We see l&rg lesions and ;e also see coalescence of lesions which has given rise to a large massive shadow In the Ro .ntgsnogram, . d close Inspection shows obvious tuberculous complication* I y 193l The next slide also manifests the tuberculous cos. plication suca as here, coalescence of lesions with a mass ive area of fibrosis, complicated by tuberculosis with the production of an excavation in which numerous tubercle hacilla were found# How, the lungs of some coal miners show also the complicated features which accompany other pneumocionioses# For example, the next case, that of a while male subject fifty-three years of age, who had been employed for many years in a coal mine, a bituminous coal mine* Now, I can not give you all the details of his occupational history, because this is a relatively recant case and we are still seeking them# The medical history, the patient developed a spontaneous pneumothorax, and we can see it on this side# Hare is the edge of the lung, along -he lung after an at tack of coughing following a cold# The X-ray at this time shows a spontaneous pneumothorax on the right, estimated degree of collapse about sixty percent# The impression is given that within the collapsed portion of this lung, there is definite noaulation. On the left, several areas of rarif'ication are seen in the upper half of this line# with the loss of pulmonary markers which are usually present in a healthy lung. The impression is also gained here that nodulation is present# 19U-* The next elide, eight days later, now, a hydropneumothorax on the right has developed, a rubber catheter is inserted; there is a fluid line, and the area of rarifaction 6till exists on the left* The impression is gained that nodulation is present* The next slide is a section from the right lower lobe in the area of consolidation seen Roantgenographically. It is a common fluid hypostatic pneuraonio process* Wo will not spend much time on this particular feature of this case, but note also the scattered areas of focal pigmenta tion, and also the rather coarse emphysema* The next slide, the right upper lobe seotion and also sections from the left lung, we sea the isolated lesions which are not too numerous and hare and hers, stellar in shape, projecting along the alveolar walls* Wo see the emphysema, but what is more troublesome, in scute of these cases of coal miners, and indeed it is not specific i for the coal miner, we also see it in those individuals whoj have inhaled free crystalline silica, mixed with other com ponents such as the iron miner, the magnetite miner* Wo see large areas or: dust pigmentation presumably due to coalescence of the igmentatlon, but we find areas of liqut . ~ i faction necrosis within those lesions* | Now, this liquify ,tion necrosis is also very : troublesome, although we believe that in the majority of ! 135*. instances where coalescence of lesions has occurred where large massive areas of shadows develop in the teBt Roentgen, that that coalescence is due to a complicated tuberculous infection# Yet, there aro those cases, with necrosis, with liquifaction and Indeed with excavation, where we have been unable, with all means at our command, to detect the pres ence of the tubercle bacillus or to see evidence of rsactior. which characterizes tuberculosis. Lest were led to believe that coalesoence and necrosis and liquifaotion may be due to agents or to factors other than infection, and we have advanced the view that perhaps high local concentrations of dust may bo responsi ble for some of the necroses, or that the necrosis seen in these lungs were - with mixed exposure, where there is pre sent carbonisation material in large amounts, where there is present iron oxide in large amounts, that perhaps this necrosis is a specific action for compounds in the dust, other than the free crystalline silica. Is it possible that the c&rbonation component, that the Iron component, may have a power of absorption or adsorption and so keep j localized the toxic substances, perhaps libsrated from the j free crystalline silica particles and some dust irritating ( particles which certainly may produce this necrosis. Car- I tainiy infection is considered - and I mention that - in- | faction other turn may produce tuberculosis, is a possibility .156 and I submit that the demonstration of tuberculosis in some of these cases, can not be accomplished* The next slide, if we take a micro-photograph of these areas of liquifaction, some of the things which I have said become more clear, as for example, here is a micro photograph of that area of liquifaction* A connective tissue state, we see the typical collagen, sustained with co nactive tissue, as we see, which characterises the re sponse to free crystalline silica* We also see the heavy black pigment which has been inhaled and deposited in thi3 coal miner's lungs and we see the area of necrosis and liquifaction* There is no e/ldance, histological evidence of tuberculosis infection. Then what is this due tot And I again submit the roasons for possible necrosis and liqiiifaction other than infection. The next slide, and this is the character of the stellate lesion as we like to identify it, the irregular lesion which is not discredt, which is not the run or order j of classical nodular silicosis or the reaction of the lung to pure free crystalline silica, Wa hare here the whirling; of fibrous tissue which _iarac ter isos the reaction to free j crystalline silica and we have had the color of plgnented __ t h a t collar of pigmented tissue, about the lesion whichj extends, as you see here, a ng the alveolar wall, a - also' ] the distortion of the adjacent alveolar spaces. This is an 12L* important feature which I will call your attention to ahorv. ly. Tha next slide, in addition to the area of liqul- faction necrosis without detectable infection, is the focal reaction present about small deposits of coal dust in the lung. How, this focal reaction has been described by Doctor Goffe* It has been described by others* It poses a problem j which is difficult to solve and perhaps has not been solved* The focal deposition of dust with its reaction, the focal emphysema, is troublesome because it is a large factor in the respiratory disability perhaps of these coal minora, and hare we have a case, a gross section of the lung of a coal miner, in a bituminous mine* He was a machine man and a loader for seven years. Here we see the focal depo sition of dust scattered throughout the lung, different portions of the lung. The lesions are stellate in shape and ra can readily see the distortion, the increase in sise of the alveolar spaces, adjacent to those focal deposits# That then is the focal emphysema which has been so clearly defined by Doctor Goffe, and which has been referred to by j Doctor Fletcher and his co-workers* ; The next slide, and we stain these lesions spec- j ifically for a certain - with certain special stains and wei note the heavy deposit of coal dust and we also note a j proliferation of collagen, wnich permeates tha lesion, and 12fta we can see the irregularity, we can see the emphysema and , also the projection into the adjoining alveolar space* The next slide, another case -- no, this la the same slide, eri here it is, showing you the infiltration of the adjacent alveolar walls with coal dust which has become deposited in the wall, the thickening of the wall, the relative or the degree of - the sparelty of the collagen, formation of collagen such as we would see if pur free crystalline silica were deposited in those walls and we seej t the large alveolar space, this is the anatomical form oi j emphysema aswe see it* j i The next slide. This emphysema is more pronounce^ J and these, ofcourse,are advanced cases and this - you , i can readily visualize, belongs to the - one of tne stages! so well described by Hoctor Fletcher, of a bituminous miner j for thirty-sight years* Ke was a mule driver for a number of years; he was a machine man and motorman; he was a coal ! loader for approximately twenty-four years, and he was a j I trackman* j His symptoms began approximately six u's prior j to death and they were increasing respiratory and cardiac ! difficulty. The X-ray, in r edition to these areas of mass-, ive shadows, shows scattered focal shadows throughout the : lung. There is also marked prominence or the left ventric-: ul&r calls and the transfer diameter of the cardiac silhouette 199 is somewhat enlarged. The Roentgenographic Intarpreatlon i was that in the presence of an adequate history of exposure to free crystalline silica, the changes visualized in the lungs are compatible with a Roentgenographic diagnosis of silicosis with conglomeration. Post morten showed advanced arterial sclerosis, coronary involvement, cardiac hyper trophy and dilation. The next slid. The gross lung in this case is heavily pigmented as you see here with black pignent and, of course, one can also readily recognize the coarse emphy sema present. The next slide, and the section of the right upper lobs, the emphysema certainly is now most pronounced and most emphatic, and now again, we see the focal irregular deposits of pigment extending into the adjacent alvaolar spaces, the small portions of the lobules of the lung are emphasized about these, and if w pick many of thorn up, there are largo or more coarse emphysematous areas. There is, near the hilar r-avion, this area of massive pigmentation. The tracheobronchial lymph nodes are enlarged. The next slide. That was from the right upper lobe. This i3 the left lower looe. Again, tne emphysema now is more pronounced. Of cours;- , gross emphysema, and the massive area of pigmentation. Of course, this is now j the emphysema beyond the 3tage which is so troublesome. ! course, this is the progression, no doubt of this small j focal area, areas of emphysema which occur about the depos its of dust. And now, the question arises, did the emphysema exist before the pulmonary deposition of dust? Would the emphysema have developed without deposition of dust or is the emphysema rela .ad to or caused by the deposition of dusjb I in the lung? I an. unable to answer the first two questions^ namely, did emphysema exist before the pulmonary deposition of dust in this case, or would the emphysema have developed in these cases without deposition of dust? That demands a number of studies which Im sure you will hear more about t in subsequent days, but the question is, is the emphysema j related or caused by the deposition of lust? This picture of focal emphysema has been ade quately described by Goffe and I should like to show some of his preparations which he has so kindly given to me# This is the section from apex to base of a co&l miner, age twenty, who worked on the coal face in a semi bituminous mine# You will note that there are focal collec tions or dust in the lung and many of than. Some have coalesced to form larger collections. However, the point j to be made is that there is little or no focal emphysema, ~ i associated with these deposits in this in3tan.ee. Thus, j the - not all cases showing local deposition of coal pig- j ment in the dust, in the lung, are associated with this | 301 focal emphysema, as seen when the specimen is met# That does not mean that it may not develop, but certainly a casaj j i in point, is that not all cases of dust are accompanied - - focal enphysema. Another section by Doctor Goffe shows the depos its of coal dust in the lung and now the focal emphysema, associated with every - practically every deposit of this dust in the lung. The next slide# Four points of reference at this time, I should like - I present the normal lung, a section prepared by us in accordance with the Goffe theory, and we see one lobe and another lobe of the lung of that side, and note the absence of pliant, the black foci that you see are crcss-sections of asperducts; note the uniformity in size of the alveolar spaces* Note no focal emphysema or gross emphysema* The next slide* Let us locus our interest now on i this focal emphysema which characterizes the reaction assoof- iated with the deposition of coal dust in the lung and which is responsible, I believe, for most of the emphysema, focal emphysema, and thus responsible in large measure, for the respiratory difficulty experienced by some coal workers* j Here we see the deposits of coal dust in the lung. Na see that the alveolar walls are pigmented with this da- ! oosit, that some of the alveolar walls are apparently | 202. tnickened and then ruptured with projections into the ad Joining alveolar space. The next slide. We'll go hurriedly now. The higher magnification s: >ws the deposition of this coal pigment or coal dust in - again in both sides, sometimes about a vascular trunk, forming thick collars, but the point to be mads here is that this pigment is not concen trated immediately about the wail of the vascular trunk, but it forms a thick wide collar, and as we look at it closely, we find a3 :o the deposition or formation of thin strands of collagen, showing that there is a reaction to i tiiis dust d<&posi. vd in tiio lung# Tho next slid -- and a connective tissue stain of that lesion, again the vascular trunk, the - again the heavy deposit of black pigment which tends to obscure the collagen which is formed, and which makes histological study difficult, t it note also the blue collagen which has | responded to this deposition of coal dust. j Now, is the focal emphysema that we see associated with these focal deposits of dust, due to the collagen da-- J positior and formation v .ich we see here in these deposits| of coal dust? Is it possible that those foci have re- ( action, that they act as anchors and so inhibit the natuz-j al function of the lung In those i.cnadlate areas, or Is it because the cnanges - the r.cr.t slide - union this -sorely1 shows tha area of higher concentration due to the response j of free crystalline silica, due to pigmentation -- or is the emphysema due to changes in the vascular trunkaf Or the blood supply to certain areas, as for example, here we see, a large vascular :r>unk sustained with elastic tissue? We see the lumen of this vascular trunk whioh is consider ably narrower and smaller than normal. We see the elastic membxane and we see the deposit of coal dust about this vascular trunk. The next slide. And, in other instances, again the wall of a vascular trunk, the inner elastic tissue and here we see the deposit of coal dust, and hare we see tha deposition of collagen, Actually involving and impinging upon these vascular trunks. The next slide. Or, in other instancos, we sea the vascular trunk in the center of an area of pigmenta tion, almost occluded. Is it then possible that this focal emphysema which we see, and the respiratory difficulty in these coal miners, may be due to these changes in the vascular trunkf The iiext slide. Or, is the emphysema and the re spiratory difficulty, more directly due to the involvement i of the pulmonary tissue per se? For example, in this in- I stance, with deposition of this coal oat in tha alveolar- I wall and its associated inflammatory response, could it be ; due to that, and Incidentally, we see here a body which is elongated with segments, and al3o with bulbous ends,. They simulate the asbestos bodies which we see in asbestos work ers* I have six cases in which we have discovered similar bodies. These have been reported by a good group, a large group, of other workers. Whether that asbestos body is due to really an asbestos bocy or whether it is a reaction to an asbestos fiber which has been inhaled incidentally, or an asbestos fiber from soma fusos used, I am unable to eay. And, we soe now, tl:r stellate lesions, changes per ae, extension along the collagen, extension along the alveolar walla, aisportion of the alveolar walls, degener ation of the alveolar walls, loss of function of the alve olar walls and its aoccsnpanying distortion of the alveolar space, and emphysema* This slide again shows the thick- j ening of the alveola wall, obliteration of the architec ture of that wall, loss of vascularity, the deposition of collagen. The next slide -- and here is a sedtion of the luns: of a coal miner in which we soe almost complete oblit eration of the alveolar wall structures, replacement by j deposition of collagen. The next slide -- and elastic tissue stains. We see adjacent wails of the elastic fibers, quite prominent, we study the pigmented wall. It is diffi-j cult to see the elastic fibers, but I have not detected , any Significant different in the character or amount of t^v elastic fibers which are present or absent in these areas of pigmentation* The next slide* And we see here, complete ob literation of the architecture of the lung, by an involve ment of the perimysium, pigmentation, hilization of the alveolar walls* The next slide -- And, is the emphysema and the respiratory difficulty due to obstruction of the i major air spaoes or passages? We do find areas of pignen- j tation, association of reaction, expansion of the alveolar j ! wall, and repression of the small air space* j Next slide* In other instances, we find that the; j respiratory bronchiole is filled with mucous or with int flammatory obstruction* Is It possible then that the vas- j cuiar changes, that the hilization of the alveolar walls, j that the obstruction of the respiratory bronchiole, which we see in theso cases, Is responsible, as individual fao- j tors, for this emphysema and respiratory difficulty, or is ! any combination important? Uov, I should like to snow you quickly a few ; other slides. The next slide. Although focal emphysema j is discovered in the lungs of many coal workers, neverthe- ^ i leas, it is not unique for the deposition of coal duat in j the lung* It accompanies also the pulmonary deposition of j other types of dust inhaled by workers In otaer forms of 206. occupation, as for example, and quickly, the lung of a granite cutter. Again, we see these areas of reaction to the dust, and we see emphysema about these foci. Here and here. The next slide -- A molder, in an fndustry, and we see the deposition of dust with its reaction, associated reaction, but not age~n the focal emphysema. The next slide --- Im. sorry, let's go back to that slide. This is a diathermacious earth worker and we see the reaction, and the focal emphysema. The next slide -- A molder, and we see the black pigmentation, focal emphysema localized about the pleura, about the areas of deposition of dust, and also the coarse emphysema. The next slide - a magnetite workers for thir ty five years, again the focal emphysema and the areas of reaction to the free crystalline silica, which this worker has inhaled, with collars, irregular pigment extending in to the alveolar walls, in this instance* The next slide -- a hematite worker. Again, the emphysema which seems to be more prominent about the areas of dust deposition. The next slide, a graphite worker, again, the focal emphysema. The next slide - a carborundum I worker; again, the emphysema which seems to be most promi nent about the areas of deposition and about the areas of i reaction. The next slide, a limestone worker, and again i *202 tha focal emphysema. So I then submit that focal emphysema, although it may be more prominent in the coal workers* lungs, and although it may assume a greater degree of - may beecma more manifest in the coal miners' lung and may be respon sible for much of the respiratory difficulty, particularly should it progress, yet it is not unique for the coal minors lung. Thank you. (Applause). BY DOCTOR DRINKER: Any questions to ask Doctor Vorwald? (Ho response) I suggest ve have a five-minute recess. (Recess taken from 11:20 to 11:30 A.M). BY DOCTOR The final paper tnia morning is by Doctor FlotohaJf on the Epidemiology of Coal Workers* Pneumoconiosis in Wales. Doctor Fletcher. BY DOCTOR FLETCHERt I*m afraid the title of this paper is. a little bit wider than that. Strictly speaking, I*m going to talk about the Epidemiology in Great Britain, because some of the great interest in the epidemiological features of this dls-; ease in our country, is the difference in the prevalence of! this disease in the different parts of the country. ; So, first of all, for those of you who know as