Document xdbwqmErXYJjpxbDpe3zBX25G

FILE NAME: Saranac 7th Symposium (SSY) DATE: 1952 DOC#: SSY005 DOCUMENT DESCRIPTION: Text of Presentation by Author Unknown, Followed SSY004 Strictly* paauroooniosi* scans a "prooess is the lungs caused by dust* sad ia thcorstioaliv initiated whan the f irs t dust particles baecne lodged is tb s lung parenchyma aad eauac any raactio s. Bor P*"**^0*^ pirposas tbs definition of untrmnrnrrl m 11 proposed by the International Ceoferaaos of the I.L.C. is Sydney i s 1950 is reasonable: "Itomaocaniosis is a diagnosable disease of tbs lungs produoed by the isbslaticB of dust, the taro 'dust' being inderstood to refer to p srtiailate Better is tbs solid phase but **^iy*lTig living organisms". The tent 'diagnosable' here isplies the prescaoe of signs or symptoms, but aot slvsys loss of function (p n s . 5 ad 27 of the report of the Conference). To Be tbe word 'disease' here implies any abnormal eondition of the lings. I t is always difficult to define just where normality ends and abnormality begins. Bo sharp distinction can be drawn between tbe aoewulatien of soot or dust is a town dweller's t-ung and the earliest changes of coal pneumoconiosis, or even silico sis (1,2). I t would be reasonable is scene eases to speak of 'torn dweller's pneumo coniosis". I s scientific medicine the diagnosis of pneumoconiosis should thus be Bade as soon as any characteristic change ear. be detected, whether this be clinical or radiological during life , or histological after death, so long as this change can be reasonably attributed to the preae&ee of dust. In most forms of pneumoconiosis histological changes are the firs t to appear, and radlflogical abnormality praceoes the appearance of clinical or functional changes by aany years (although is some forma of pneumoconiosis such as asbestosis and byasinosis the reverse is tru ej. These radiological changes are due to dust in the lung and must for scientific and logical reasons be regarded as constituting pneunoccsics I fael there is some danger is using s definition based upon h ist ological examination of lungs because i t cay encourage men to undergo lung biopsy ir. order to obtain histological proof. TTithout lung biops; c histological definition cannot be logically applied during life . KEwE.VID F-H.HIS - 2- WI4.E.ML j J k l l J B . 501S The only objection to applying the ten t jnranoecnlMia to oases without disability is psychological. 1 ass say be told that be has pneuno- ooniesis on the grands of radiol ogical evidence, and nay then he disgruntled i f he be not granted oonpeasatim: or, i s as area suoh as South " ales where large mnbera of sea are seriously affected by the disease, he any be alsned by the diagnosis sad develop as andety state. Pros this point of view i t would be advantageous to hare a separate tern which would be used for neo-disabling pneumoconiosis, but tinoe and pneuaoceoiosis are usually but different stages of a single pathological prooaas, i t would be illogleal in scientific nedicine to uoe separate te n s . Moreover, radiologists or pathol ogists , as they classify radiographs or sections of lungs, eannot distinguish the disabled fxm the non-disabled and mist apply the t e n penunoccr-iosls to every esse in which they find shnonaality attributable to dust. Zn the Pneumoconiosis Jteseareh TfrsLt we have net found i t difficult te explain to s nan that his radiograph "shows that he has been e niner, but does not sfrfwr enough dust to do any baits" and that he eannot therefore expect oampenaitior.. In border-line eases also we here found no difficulty in explaining t.s t doctors as disagree with one another in assessing the severity of the disease so that in such eases, while application for ecBpensation nay be worth staking, the :aan bus*, not be surprised if i t fails despite our own diepsoais of penmoconiosis. (Ve have found that the 7elsh coal niner x la such store ready to accept the existence of observer error --> doctors t VlT' are nenbers of the nedieal profession tbenselves!^ For this reason Z do not think that there is any need to introduce a new ten: for ner.- corpensatable pmeusoconiosi*. For purposes of ccopeneation i t nay be necessary to define a lic it cf j|ueoeptable abnornality (whether clinical or radiological} belerr. which an official diajptosis of pneunoeonioaia w ill not be rtade, and which nay lie above the lowest lic it recognised by special investigators. I t is for legislators to decide whet they want to have esepensated - disability, leas of earning ee*j*city, shortening of life expectancy or what they w ill. I t is ther. up to doctors to attempt to devise nexus of aeasuring the factor that is to be cactpersated, and to shew the degree of accuracy with which i t car. be fceasured. /.*. present leg islators often 'decani, ard doctors are prepared to give, expressions of opinion which cannot be supported by scientific evidence, particularly in relatior. to respiratory dis ability.  . RDEACTEEI:VE^DMFi.LH?.hi1$3979 ' e5; 0n x' Q9 - 3* M.LM * also to anrwldar wbrtbar a m b oos bo disabled by pneumoccn- l i without developing cfaaceetarlstic radiological s ip . I s Sooth Wales Professor Gough h u occasionally daaanstneted eool Winers' bags with arrore focal emphysema which suat h m boos tbo Muse of pulmonary disability during life tut which m r onaasnrletad with the radiological ataonaality oharaeteriatie of jewMoocnlM l a. toefc oases, h o m r , i n y imnawan. Fulmooary disability sttritetahle to dust ishal st i es way also arise is %ysslsesis aad asbestosis without any characteristic radio logical ohaze*. Sr. Hugh Jonas w ill shoe in his paper tanoRM thatjin the aaspls of aiao n and aoo-mlmtrt that m hare studied,the adacR withort any radiologioal sipw of pnoisnoocr t Mia appeared os the average to have impaired ventilatory eapadty ahen oce^ared with noo*iera of the sir* age. This impairment was in oooe eases associated with a tendency to bronchial apaax. Whether th is disability is sttributsble to dust inhalation we cannot yet say. The sample was a n a i l one and the R su lts way net be generally applicable. Further studies of such larger samples of miners and wen working in other dusty and nce<4usty occupations w ill be required to establish whether coaldust inhalation oan disable without pausing radiologioal changes. Our preliminary findings do suggest that w nay at present rsly too such upon the radiological changes in deciding compensation for disability ir. simple pneuaoconiotis. Until we knew nore about the relationship between disability and severity of radiologioal change frm studies en large populations of miners and cx-oiners (not on hospital populations, nan applying for ooopensation or working populationsf e&ich are biased in R lation to disability) we shall net be able to n y what emphasis should be placed on disability measured by clinical cr physiological net-hods and what emphasis should be placed as the radiological picture. Active and Inactive Dusts The pathological activity of a dust depends net only on its chemical nature but also on its physical characteristics, ruch as sire distribution, en upon the dose administered, so that no simple classification of dusts into active aad inactive is possible. For example, a given quantity qf 20 Angstrom silica may be highly active if given in a single large dose, but the sane quantity nay have no effect at a ll if administered in snail concentrations ever s lone*r p e rm i t night be possible to reach a theoretically sound classification of dusts according to their activity cr. the basis of the relationship betreer. the amount of materiel retained in the lung and the degree of pathological change. aV. RECEIVED FJI.HiS t 4 - iHuItfM JUl ? 1 ^ 7 9 5020 Tiara, as active teat would be ana la white the degree of pathological reacti to ita preeaaoe la the lo g la groat la relation to the aaouct at retained aatcrlal (a.g. allloa end baryllim ) and an Inactive teat would be one la white the patholog ical ehaage la relatively anall (e.g . ooal and I n c ), bat here we aeet the difficulty that dusta oust aa ooal white would be olaaalflafl aa inactive per a nay, la oenbin- atiea with tubcrouloua infection, produce groaa pathologloal ohaagea. day olaaslfioatian at testa late active or Inactive on tee basis of anlaal axpcrlnests aay be daageroualy alslaadiag. Ooal teat vaa for years regarded aa bazalaas la Great Sritala aaft la a tlll a regarded la Ge.-aaay, largely beoauae animal longs do not ahoe any flbrotle response to Inhaled ooal teat, and yet the inhalation at doal dust has disabled acre than 20,000 ooal workers la South Traits during the ^ ast twenty yean. Silicosis - Dr. Vorwald asked m whether allleoala la a "disease'' or a "condition". Z don't ate any difference in the swaning of these two words. Z regard any path ological change attributable to free allies aa a for* of silico sis. Z distinguish tht formation of uniformly distributed oonoantrlc oollagencus flbrotle nodules by the tern "Classical nodular silicosis". Terras for Specific Entities The word silioosis only be used teen i t has been d early demon strated that the pathdogieal changes In the lung are attributable tc the action of silic a . So far as Z know this oan only be done where the dust exposure is to pure silica or where the reaction in the lung is of tee classical type. For all other pulmonary disease tee to dust the word pneunoocnioais shtruld be used, preceded by je nase of the dust or occupation by or in which the disease is caused. The tern, "astbraoo-siliooais" should be applied only to tbaee eases of classical silicosis in which there are also deposits of ooal in the lungs ( for exsrple, rock workers in ooal Bines) but should not be applied to the ordinary ooal workers' pneumoconiosis in which there is no evidence that silica is responsible for the fibrosis. Clarity is gained in referring to the pulcanary conditions attributable tc specific dusts by using prefixes tc the word pneumoconiosis, e.g. soot pneuno- \ jniosis, talc pneumoconiosis etc. 1, Dsvaon J . and Suanan,T7. (1937), J . Fth. B eet., 45, 557. i. Harding, H.E. (I9i5) Proc. 9th In t. Congr. Industr. V.ed. 19^ Lent- P-692.