Document JZrxvQ2L5qg7Mq5Qp5yR2RgB

FILE NAME: ZD^D/ DATE: & DOC#: ^D/ DOCUMENT DESCRIPTION::ZDd WZZZZZ I 02- ,;anad. :\1. A. J. ] Feb: 1950. vol. 62 llIEREWF.THF.R: PNEU~lOKONIOSES 169 quire our school authorities, local provincial School authorities and local provincial and Dominion governing bodies will find it necessary and Dominion governing bodies; to provide adequate clinics for the reception and treat- d, and monies to to take greater interest and provide more facilities for the examination and training of the ment of the deafened chil further the work so ably started by doctors in hard-of-hearing child. I the larger medical centres.4' REFERENCES 1, FISHER, G. E.: Eye, Ear, Nose & Throat .lfonthly, 5: j It is the opinion of all otologists that the 2. 222, 1949. l'vIACFARLAN, D. : J. A. JI. A., 137: 774, 1948. care of the deafened must be commenced early 3. 4. FEE, G. A.: Nat. Soc. NEWHART, H.: Trans. Deaf., 1948. Oph. & Oto., :March, 1943. in life. It is also recognized that the doctors are anxious and willing to carry out the treat- 925 W. Georgia St. ment and re-establishment of those who have serviceable hearing, but it is recognized that I one on a provincial THE PNEUMOKONIOSES: ! . befo1e any work can be d t . 'or D9minion-wide scafa, the Departments of DEVELOPMENTS, DOUBTS, Health and Education must provide buildings, DIFFICULTIES~' i .' equipment and lay teachers, to re-habilitate E. R. A. Merewether f those deafened children who require speech 'training, voice correction and re-habilitation in H. JI. Senior Jfedical Inspector of Factories, i -j . - their lives. We know little has been done on Great Britain, London, Eng. ~ ::'. ?' any concerted large scale. It would therefore I -..,:; seem necessary that we, from the several PREVIOUSLY in the history of the pneumoave been times when the t - provinces of this Dominion, should return konioses there h path of progress has disappeared in a forest of '_! buoyant in the hope that work would commence data and the traveller was beset with doubts. It as soon as possible on a program for the diag- seems that we have reached just such a point nosis, treatment and education of the hard of .. hearing child. This was stressed by the Presi- now, when we must stop and take our bearings. really is the present position 1 In anadian Otolaryngological Society Firstly, what England we have some 800 deaths a year from . <lent of the C . in his address before that organization. pneumokoniosis and. there are over 16.900 cases SUMMARY registered as ''disabled persons''. These num- ,,_.-. There are children born deaf and there are bers may not appear striking compared with the 4,000 deaths a year of adults from road others who become deaf between birth and two years of age. Ordinarily, these will not be able accidents and the 20,000 deaths from respiratory tuberculosis. But, when we stop to try to esti- ~ _,. "':Cto learn to speak. mate the relative risks of death from these Heredity is responsible for only 25% of causes in relation to the numbers of people _ I, ll()afness in children. Early diseases of child- exposed to them, then the risk from pneumo- hood cause 75%. koniosis appears fantastically high. On this Early training of the hard of hearing child basis, the figure of 800 deaths a year from pneu- :. is necessary. mokoniosis would have to be multiplied by ... Surgical removal of infected and hyper- an unknown but large factor to view this risk ;f :- -->trophied tonsils and the Eust~chian tube, adenoids, the patency of is one of the first. ''~rgical in correct perspective. It can be said with certainty, however, that a few months' exposure to :; _- . : procedures in treatment. . ,. silica or asbestos dust in gross or, to use Leroy f :/' '. .c . Radium applicators in the fossa of Rosen- Gardner's happy word, "insulting" concentra- ~:"{:.":; : ,mueller may be necessary. tions will inevitably cause death. However, t~-:?~~S' Children. in eleme~tary sch~ols are group- f~"~:.-~;>: .tested and if found with a hearmg loss of more when we go further and think, not of one small country, but of the world and consider the toll f_:::.:i~{:~~/than ~wentyThdeecaiubed~1,0maereterr~isfebrre~mdgfoursefdurmthoerer of life throughout the ages from these diseases from all the mining, quarrying, fabricating and . '~-;.:;--;;- , attent10n. i ,.~fft;: -<and more with greater satisfaction to the construction work carried out, we may well l ..,:7::: : otologist. * Read before the Eightieth Annual Meeting of the '.:~.'~~-f-\~~: Institutionalizing ~ ' avoided if possible. of children should be Canadian Medical Association, Section on Industrial Medicine, Saskatoon, June 15, 1949. l''i-1::. - . ... ; . . ' ..- ' ~) I '' : .-.....l. ., ' ...; '..- ": , .<; . '.,. ---. -. ~: ' .. :~ ,, \' ... - r ~ ..... >:,,.... .: r~. ' '. , ~- '-. ,;- ~ ~ ~! ~-: ' ' :~ . .,.!..,. .'..~.. ,. ~ t _.. .........,. . ,,..._ ~t \,- .;.' -. ,. 'f -~ .... ,'. .,t~~.. ' .\k~. l. : .;.. . ~ .--~ .: t ' ' .:;./ / 170 .MEREWETHER: PNEUMOKONIOSES Canad. :If..\. J. [ Feb.1950, vol. Ii~ regard them as one of the major scourges of humanity. Again, when we think of the achievements of medicine in preventing and curing diseases like diphtheria, we cannot help but ask, with some- thing of shame, why the mortality from these dust diseases remains so high, seeing that in theory at any rate, they are wholly preventable. It must be confessed that understanding of the problem and of its urgency, by the professions, managements, workers, and the public generally, is inadequate and ill-diffused and we cannot hope for real advances until this is rectified. This comes about because the pneumokonioses have no spectacular impact on the community, like accidents or dramatic epidemic diseases which make news headlines: silently and insidi- ously they creep, like old age, upon their victims distributed over many industries, who fade away with little but local disturbances. They are difficult to diagnose and often masquerade as other dis-eases. The medical teaching schools and textbooks pay little attention to them and nothing to the industrial processes which cause them-without a knowledge of which, diagnosis is but guess work, and also, the terminology used is vague and confusing. What is needed is national and international team-work like that applied to the study of atomic energy and then a very large measure of control of these diseases would be assured. The first steps are to aaree 0 ' internationally, on a standard terminology, standard criteria of diagnosis, standard x-ray technique, and standard type films, minimum standards of preventive measures, of compensa- tion and rehabilitation procedures, strictly en- forced by law: priorities of aspects for immedi- ate research on the medical, engineering and other scientific aspects and, above. all, we need intensive national programs of education with the aid of the popular, professional' sci.entific' and trade papers. Instruction should be made compulsory in relevant degree and diploma courses, in technical institutes and trade schools, and for workers, managerial, and supervisory staffs engaged in work which involve risk of these diseases. Let us look, very briefly, at some of these points. Consider first .the confusing terminology used with these diseases. So far, I have had to use the words "these diseases" with the equally vague alternative ''pneumokoniosis'' in this discussion, for this very reason. Pneu- mokoniosis means ''dust and the lungs'' a Va!!jue generality which indicates no particular entity and implies no pathology and no dis- ability. To medical men it means, without further definition, merely ''any respiratorv condition which may be ascribed to dust'~. 'rhus, it may include anything from an ab- normal x-ray picture as seen in welders, or silver finishers, or iron-oxide workers, due to diffraction of the rays by minute particles of metal dust which causes no symptoms, no di~ ease, and no disability, to gross fibrosis of the lungs with extreme shortness of breath, com- pensatory emphysema; pneumothorax, bron- . chiectasis, and gross pleural, pericardia!, awl diaphragmatic adhesions, as in advanced asbestosis. It may include cancer of the lmw due to radioactive dusts, beryllium granuh;: matosis, and all the curious affections asso- ciated with workers handlina arain baaasse . 0 0 ' 0 mouldy cotton and hay. Clearly an expression which implies both trivialities and most seri<ms diseases is of no practical use and is liable to mislead. Again, consider the expression "siderosis ". It was coined first I think, as a respectable name for "grinders' rot "-which. at least, told us something-to describe a~ interstitial fibrosis of the lungsJ;hen thought to be caused by fine metal particles: a quarter of a century later, some people used. it as a name for silicosis in hrematite miners, and now, after another quarter of a century it is used to de- scribe both the killing fibrosis of hrematite miners and the harmless spotting of the lungs by fine metal particles, discernible only by radiography. Then if, in desperation, we turn to the dictionaries, what do we find 1 Taking one at random, after stating the derivation- of pneumokoniosis to be from the Greek, meaning lung plus dust, it goes on: ''A. lung condition due to the inhalation of minute particles. It is attended by fibroid induration and pigmenta- tio~. See aluminosis, anthracosis, asbestosis, byssinosis, chalicosis, ptilosis, siderosis, silicosis, and tabacosis." As you will observe, some of these expressions are merely alternative appellations, some may not exist and a number are not necessarily attended by, and are certainly not associated with, fibroid in- duration of the lungs. But, let us not give ~P : on turning to "ptilosis" we are told it is "a form of pneumokoniosis caused by inhaling the - : Canad.?J.A.J. ] ,-_ .: Feb.1950, vol. 62 :MERKWETHER; PNEUMOKONIOSES l 171 \ l = dust from ostrich feathers". What this defini- the diagnosis and cause much hardship and instice. We need, therefore, medical, scientific, a. !' tion really means only the bird knows. I will eary you further except to remind you ju and industrial knowledge and so-team work of .: _. _. not w s are used, as for instance, the best class. that compound name .,:.. : silico-anthracosis and I have seen several cases You will note that the points I have men- 1 :~:>- with both silicosis and asbestosis to which, tioned-eausative dusts and processes, clinical I no special name has been findings and x-ray appearances-as the basis of : ~-~, -- fllrtunately, as yet . _ applied. This is confusion worse confounded: diagnosis, are also the basis for progress. With- l' ' wonder we mislead and are misled and when out accurate diagnosis the harmfulness of a dust t:_:. l ~: 1tfh1le0ee etoxp~ehretsdiccotliloindaeriinest,haenfdogw, htahte~cpoaurratdsio~felfaowr and_ the hazard of a particular process cannot be assessed, and without these, appropriate pre- ,,._. our: fnends the lawyers. We simple mmded ventive measures cannot be devised. I cannot ff. _/ prac~ically dispo.sed persons, stress too much the importance of accurate diag- ,. and, of necessity,_ ~.::_~- must really avoid bemg hypnotised by the nosis and this, it is vital to remember, involves h.;:.:~-.~:,~pthheerosr,etaicnidantisdyanud~ tshhiascnkolmedenbcylattuhree.leIxtic~oiggrhat- t ( ~-~.:._ ~!o.fitably be chscussed and agr~ed m~er definmg non-medical as well as medical considerations. This leads to the further point that while a certain amount of mysticism is not alien to the of medicine, the age of witch- l :~<,nationally, as has already been done m j ,"~'!~ the meaning of the term ''silicosis''. art and science craft in the practice of industrial health is long rc~:~-~<rn some countries, the law has had to step in since past. Apart from the fact that the patient ne~ds a reasoned prognosis which necessarily is ,' "f" t _--*~E;~ .for its ovm urgent purposes and tell us what f .:._:-..:nv~ mean; 'for industrial health is dependent based on accurate diagnosis, managements canaid upon them ; 'not g: ._ .,. __.-.. ~ ''~-'~-- only 'I on\ doctors and nurses but also on not cope with the responsibilities l by law without skilled medical aid, and con- . ' f::i~tengineers, chemists, physicists, and so on .and l::i{'-!;~i ia primarily a responsibility of governments sequently may be quite knowledgeable in these r:~,L~'.~an_d. o-l industrial managements, and so every- r':--~-"t,, :~"" mus~ understand e~actly what is matters. Now what do we know of the relative harm- fY~_;,~~}ne concerned "'-'~'.~;\ meant: and reqmred. Thus, m our own . fulness of dusts? Regrettably, not .r' nearly enough. ;:z5F. -. National Insurance (Industrial Injuries) Act, :~:~~:~.\~~ find that ''the expression 'pneumokoniosis' Nevertheless, we can make some useful generalizations. The first is, that all dusts whatever -- :-~~~,:;/.means- fibrosis of the lungs due to silica dust, -~~~:,_~-~'asbestos dust, or other dust, and includes the their composition will cause functional damage, but only some kinds have been proved to be , ' . '.~ :r:;:'.~<--wnditfon of the lungs known as dust reticula- ~:s<./'}ion-". This has its pitfalls especially in the 'use capable of causing fibrosis of the lungs, that is, true pneumokoniosis. The latter are those dusts .:;::::~:":of; the word "dust reticulation", and its clude such containing silica in the free state as SI02 and also out of the multitude of other mineral dusts, ..\ -.1 .'>~(;..;, Umitatfons, in that it does not in i:?~'.r~!-ci?nditions as "byssinosis" (which is dealt with only the small class of fibrous silicates known as ex- r::,, ", , S~parately) ; but in spite of this it includes the disabling asbestos. These in their pure forms, for ample as quartz or asbestos, unmixed with other .. {\~-.~~-:;_.,great majority of. related killing and ~~>~;fk~ .forms of pneumokoniosis, and thus is a practi- dust, and in the absence of infections particurms {~::~~?~'cnl step forward. . larly tuberculosis, give rise to the classical fo of silicosis, a nodular fibrosis, and of an asbes- ~:~2l::S:~~};Now '--:: 'I "'-l'-~e>' - a word or two on diagnosis: diagnosis is tosis, a cobweb fibrosis, which are closely re- ~..:~.:~-_;::: ~ difficult, which is one reason why both here and flected in the typical x-ray pictures. L:;~~;~~ _in England special boards have been.constituted t~~~.::~_to .d.etermine finally diagnosis and degree of d_is- Therefore, classical silicosis and classical diagnose, but ~?"10, !ibil1fy. In every suspected case, for accurate about the dust asbestosis are relatively easy to so often we find these classical types modified ... . ) ~7I~)-f_. ,diagnosis we need to know all ri0,~~E:~:-~or; ~usts MnMrnl'ld and the length of exposure by the action or mere presence of other relathe patient ha.s been ..'... ~~~'.~;t~f~hem, the complete occupational history irom l':~~f-:~~:.fl.rSt starting any work, the clinical history and tively inert dusts, to which exposed at some time or another. Infections and t;~~:J:f_ ~dings, and the radiological appearances, and some of these other dusts accelerate t~e development of fibrosis and others are thought to in- ~!:k~~: }nadequate information on and faulty interpre- hibit it, but all tend to modify, often profoundly, t~~~f of any of these .aspects can wholly wreck 172 }fEREWF.THER: PNEUMOKONIOSES [ Canad. ~LA: .l Feb. 1950. vol . .; 2 the pathology and radiographical appearance of the classical types. This is where we may run into great difficulties in diagnosis and prognosis and in the advice we give to managements. Excluding terminal broncho-pneumonias, tuberculosis is the most frequent infection. In a series of over 2,000 deaths from silicosis and a series of 232 deaths from asbestosis investigated by my department, 50 and 31 % respectively were com- plicated by tuberculosis. This susceptibility to tuberculosis is covered by our law, which compensates the sufferer from silicosis or asbestosis whether or not the disease is accompanied by tuberculosis. Exposure to other dusts such as in nickel refining by the ~fond process (which also causes cancer of the ethmoid), in the manufacture of chromates and bichromates, and arsenic, is associated with an increased incidence of cancer of the lung, but none of these dusts also causes a true pnenmokoniosis.. A point of considerable interest which comes to light from our records is the possible association of asbestosis and cancer of the lungs. In the same series, 13.2% of cases of asbestosis were found on autopsy to have cancer of the lungs. This is in contrast to silicosis in which our figure is 1.32%. Little is really known of the mode of action of silica and asbestos dust and the wherefore of these variations, but they emphasize the need for most accurate data on the human cases which occur. There are obvious reservations to the direct application of animal work to humans. Scientists have propounded both mechanical and chemical theories in explanation, but as E. J. King has shown by laboratory experiment the different rates of solubility of silica from different dusts do not parallel their fibrosis producing powers. Similarly Leroy Gardner's mechanical theory as to the mode of action of asbestos dust does not wholly explain the production of asbestosis. Again, Andrew Meiklejohn and W. W. Jones, in a follow-up of pottery workers, exposed to alumina dust have been unable to find any slowing up of the disease in cases of silicosis, in spite of the promise of the laboratory experiments on the inhibition of the solution of silica by alumina. It does not follow that these theories should be discarded, but rather that other fac~ors, including them, play a part and, maybe, in respect of the added susceptibility to tuberculosis particularly, the production of an imbalance of the intracellular enzyine system is one. .Most enigmatic of all is the uis. ease described by Shaver and Riddell, and also the mode of production of the fibrosis asso<iated with exposure to beryllium, both of whieh pose questions as to the rOle of fumes in th<' production of pneumokoniosis. However, as all this may be, we must, like St. Paul, throw out a few anchors in the stotm and, from the practical point of view, free silica and asbestos are the inherently hazanlous dusts which must be dealt with, whethPr encountered singly or mixed with other tlu:sts. Although so-called individual "susceptibility". that is, the particular state of the individual's lungs plays a definite part, naturally, the greater the amount of silica or asbestos inhaled, the greater the damage to the lungs. But, an important point is that they may he present in quite low propor.tions in .a mixture of dusts and yet cause much damage. Thus I have seen death from silicosis from exposure to an inert dust containing only 10% of added free silica and some samples of French chalk containing less than 10% of free silica and some asbestos, can cause both silicosis and asbestosis at the same time, althottogh the pure material is inert. The reason for this is not difficult to see. A certain amount of silica or asbestos must be retained in the lungs to cause disabling disease, and the effect of overloading the lungs at the same time with large amounts of inert dust is to disorganize the normal lymphatic drainage, and so ensure the reten- tion of the dangerous dust. This may well be the mode of production of the coal miner's lung, the result of exposure to massive concentrations of coal dust containing very little free silica. With exposure to con- centrations of dust of this order, local blockage of lymphatics caused by overloading with dust, or by infections, will prevent the clearing of adjacent choked lobules and give time for the silica, a tissue poison, to act. Thus, we get a. condition of focal atelectasis with focal fibrosis and compensatory focal emphysema through- out the lungs, as is beautifully shown by Gough of Cardiff University in his whole lung sec tions, and this is a clearly progressive condition with continued heavy exposure. \ So far I have touched generally on the problems of the true pneumokonioses, dusts in their etiological aspects and the pathological features .f} .. -~ ~; ::'- .-' i- -<_;;: [;~:_:: ty~~~-~-~- -'} - -. -., . - -.,'. {. Canad. ~. A. J ] . Feb.1950. vol. 62 PAIGE: ~[ONONUCLEOSIS 173 of these diseases, and have stressed the vital INFECTIOUS MONONUCLEOSIS importance to progress of pooling the skill of B. F. Paige, M.,B., B.S.(Sydney)~' medical men, scientists, engineers, and manageI have referred to the many variations Vancouver, B.C. ments. AN lrom the classical types of these diseases and analysis of the last 45 cases of mononucle- the consequential difficulties in diagnosis and osis seen on the medical servic~ of the Van- prognosis and ii:i assessment of the hazard of couver General Hospital has convinced us that the causative work. I have indicated that .the it is timely to take stock of present knowledge _ J.octor's approach to problems in this field is of the condition. ~! . . three-pointed by way of occupational history, Infectious mononucleosis is a self-limited dis- findings, and radiographical appear- ease occurring in young people and characterized t. ~ clinical ances .. Now, a few words on the third point- by fe,ver, sore throat, a swelling of the cervical the radiographical appearances. This is just eadache as the other two, but is lymph nodes and frequently of other lymph nodes, an increase in the mononuclear leukocytes t1 . .vnsitamlluychimapohrtant and may be conclusive. The and a granuloprenia, and a positive Paul Bunnell pathological basis of the disease, that is the course reflected in the x-ray test. Of these symptoms and findings three are of chief diagnostic importance: (1) Cervical fibrosis, is of picture, but the classical appearances are more lymphadenopathy. (2) Increase in the mono,. l {: often than not modified by coincident tuber- nuclear leukocytes. (3) A positive Paul Bun- ! .' " culosis, or by other disease, or obscured by the nell test. l. '- - - highly diffracting effect of retained inert dust. r, different radiographical techniques Unless a patient exhibits at least two of these three findings, it is difficult to see how the f Xoreove ., . and different types of films can mislead com- diagnosis can be more than pure speculation. ' . pletely. Pending internationally agreed tech- '. niques and type films which are long overdue, All the cases in our series have at least two of three criteria, and most of them have all three. . the only practical suggestion is to collect your An analysis is as follows : ! own library of type films from cases whose t.: complete occupational and clinical histories Total Cases cases, 45. with cervical lymphadenopathy, 36 . .with autopsy findings are available. This can Cases with marked increase ' in mononuclear leuco- -,- _best be achieved by local medical societies. cytes, 44. Cases with positive Paul Bunnell test, 36. _.In discussing this tremendous national prob- Of the 9 cases in which cervical adenopathy was not recorded, 5 had a marked tonsillitis. lem of the control of pneumokoniosis, I may have given a pessimistic outlook in saying too es of the position, but The one case which did not have a marked increase in the mononuclear leukocytes had 33% ,~ . mhiustcohryabteoauctheths eusdtifhfaictualtliwadysitjsusatppprliicoartitoong,rewaet mononoufclepaorlymfoormrpshoinnucaleatrostaal nodf 42,86%50, wstiatfhf .- _ advances in knowledge an , :-' ..:.::~,; have wallowed in just such confusion. Can we 35% cells. This patient had enlarged cervical glands, f ~"- ;; hope for a dramatic discovery to guide us, such ~,,~~~~_'as that of the bacillus of tuberculosis which and the Paul Bunnell test was positive in dilution 1 :320. He, therefore, showed the main J ~ ;., .f'.'~: ended one long period of confusion as to the features of the disease. r -:~~-- ''nature of these diseases, or that of the roentgen Before proceeding with an analysis of the cases it is \. t -_ ! ... rays which pointed so imperiously the route to .:~ :. better diagnosis? Is' it too much to hope that apphpilreopagrigaltuetintoatidoisnc.ussThtheesePrauuml oBfunnrnoersmlhleaetlepss'utsborjerecdhtsebtlecooroond- ;: . .: . . lines of research at present being pursued will tcaeilnlss, wahnichagdgoleustinnoint e(xFceoerdssamtaintr)e foof 1: 8. In mdoasyts,catshees ~--:~:-: lead to a discovery of e<l!lal magnitude on the of infectious mononucleosis, serum shows an increase in after 7 to 10 this sheep's red cell ag- ~,:~&,~-::=:~~preventive side, such as a perfect inhibitor or ._:;_.:_ ~t ati 'instantaneouasmcoonftidnrueoaumslsy, arecdoursdtinagrredsutesrt glut this i nin seri an es d to t he 1 : 1 titre 0240 m ). a y S rise ever a t l o e very xami high figures nations at in (,in ter- vthaels roefsualtfeisw pdoasyisti.vme.ay Ibte insegceesnsearraylltyo adgerteeremdriitnsheeawtinhaettrihtisreeer lt~~~-e-,.~,-,_c~;oowuhnicther,coourl,d dbree worn on the chest or like a to 1: 32 or more is has been observed definitely abnormal. A. in individuals who have recently re- ~,'~->;/miner's head lamp or both, and prevent dust ceived injections onditions apart of horse serum, but it is rnre in from infectious mononucleosis. other It is 1! -r.~~.ii?eaching the mouth and nose ~~~.;;~ .'.>_face completely free from and yet leave encumbrance 1 the I c *Resident, Department of Medicine, The Vancouver -S .'.~op_e ~o. General Hospital, 1948-49. r 4 """' - ~ :r~.J--" . .. "' .... . ~: ..-~ ~ , /':: J -~.~ /:. ~ < . - F .:_ ... ,... ~. - ' < :'4.' ..: , -~ ', ' - - . ...~. -~ ~ .- , '