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FILE NAME Colonial Sugar Refinery CSR DATE 1968 DOC CSR064 DOCUMENT DESCRIPTION Proceedings of the First Australian Pneumoconiosis Conference AUSTRALIAN PNEUMOCONIOSIS CONFERENCE conference on airborne dust in industry its Measurement control and effects on health _ FIRST > AUSTRALIAN PNEUMOCONIOSIS CONFERENCE A conference on airborne dust in industry its measurement control and effects on health ii re re The copyright of the contents of this book remains with the individual authors and requests for reproduction in whole or in part should be directed to them personally Copies of this publication are available from c First Joint The Executive Secretary Australian Pneumoconiosis Conference Coal Board Box 3842 G.P.O. Sydney 2001 Gale Price 10.00 includes postage Sehs iii Proceedings of the FIRST AUSTRALIAN PNEUMOCONIOSIS CONFERENCE hold within The University of Sydney February 12th 13th and 14th 1968 es 447 ASBESTOS MINING " WITTENOOM WESTERN AUSTRALIA Dr. J.C. McNulty Physician Occupational Health Division Public Health Department 57 Murray Street Perth Western Australia Asbestos is a common mineral in Western Australia anthophyllite and crysotile have been mined since the early and 1920's but the mines were little more than prospecting shows producing at most a few hundred tons of fibre per annum and rarely employing more than twenty men Mr. Lang Hancock discovered large crocidolite deposits at Wittenoom in 1939. Because of wartime pressures the Colonial Sugar Refinery bought him out and created wholly owned subsidiary - Australian Blue Asbestos - in 1943. This mine operated until 1966 when poor fibre return labour problems transport costs etc. forced its closure From 1943-1950 production of fibre rose from a few hundred tons to 1,000 tons and the labour force from 50 to 200. Production then began to rise progressively to 4,000 tons by 1954 7,000 tons in 1958 and from 1958-1966 from 11,000 to 15,000 tons The number of men employed annually also rose to between 300 and 400 For many reasons there were very considerable fluctuations in these production figures and in the number of men employed The very high temperatures a succession of centuries in the summer the barrenness of the terrain lack of amenities the dust and a main labour force consisting almost entirely of o A machine miner in 39 stope Five of the underground miners in the series had Vibration Raynaud's Disease 4" 449 new migrants to Australia led to a very high labour turnover in the region of several hundred percent per annum Probably fewer than 20 of the men employed at any one time had been there for as long as three years That is there was probably a small nucleus of men who over the years had an exposure to dust of three years or more and managerial staff and this included tradesmen supervisors Although the Health Department first became concerned about dusty conditions in the mine and mill in 1948 and all miners had had an initial clinical examination with a chest and annual periodical chest rays subsequently the first ray diagnosis of asbestosis was not made until 1958 The first patient was an Italian migrant aged 33 years an underground scraper driver who developed pulmonary tuberculosis which did not respond to therapy and he had a lobectomy , . Examination of the resected specimen showed extensive interstitial fibrosis and asbestos bodies and the pathologist diagnosed asbestosis a Subsequent enquiries have shown that there may have been at least another two.asbestos two.asbestos miners diagnosed in earlier years as suffering from pneumoconiosis but this was recorded simply as silicosis - one had had lengthy underground gold mining and the other fifteen years as stonemason in Italy In June 1958 because of the case previously mentioned the periodical annual examination of miners included clinical examination which revealed a small group of new cases of pneumoconiosis ANALYSIS OF MEN AFFECTED Since June 1958 103 men who worked at Wittenoom have developed pneumoconiosis , Mill workers 41 Underground workers 29 Mixed underground and mill workers 6 Men with other significant mining 24 Men excluded because of lack of detail 3 103 The twenty men with other significant mining experience have been excluded from detailed consideration because of previous lengthy mining outside of Wittencom - coal in tunnelling in Italy gold in Western Australia Europe on The three men excluded for lack of detail were diagnosed chest ray alone alone - two of these for example on rays of ill men forwarded from Italy for purposes of compensation This is a general view of the mill The entrance to the underground workings lies in the face of the gorge opposite the upper part of the mill There is dust emission from the stack in the lower hand corner and tailings from the mill have been used for road surfacing oo. of 103 men therefore 33 have been 70 for consideration in this study excluded leaving INCIDENCE RELATED PRODUCTION INCIDENCE RELATED RELATED PRODUCTION PRODUCTION PRODUCTION It would appear that although poor and dusty this did not cause working conditions were the production of fibre significant lung disease whilst remained low Continuance of the poor The usual procedure was to clinically examine ray men first and then to exposure and of everyone with more than twelve months dust course anyone else who requested it As a result of this it is not clearly presenting signs or possible to identify ' ray abnormality was first symptoms In most instances a chest dyspnoea presence of basal noted but complaints of the function tests crepitations etc. finger clubbing abnormal lung were very often present Sometimes these signs and symptoms occurred chest singly or in combination with ray and several were diagnosed at normal biopsy in the absence of post mortem or on lung any of them Abnormal Chest Abnormal Chest . DIAGNOSTIC DIAGNOSTIC DIAGNOSTIC r-aryay CRITERIA CRITERIA Dyspnoea Basal crepitations Finger clubbing Abnormal lung function tests Lung biopsy mortem Bilateral pleural effusions . . 1 This is not to the earliest sign of suggest that an abnormal chest ray is that with the asbestosis This is not true It is , acute type of pneumoconiosis which merely abnormal chest ray appeared just as occurred an symptoms man with two quickly as other signs and normal chest ray and years exposure no in the mill might have a finger clubbing basal symptoms in one year but have dyspnoea the following year crepitations : and an abnormal chest ray Abnormal chest any signs or symptoms rays were also found in the absence of Unusual Unusual Presentation Presentation not Four mill workers presented with chest show any evidence of rays pneumoconiosis which did a 1 S who developed and basal crepitations lung was normal 452 pleural mesothelioms had but what one could see of finger clubbing his remaining 2. G a chronic bronchitic with dysphoea finger clubbing and basal crepitations whose ray within a very few years showed typical fairly extensive asbestosis 3. G developed tuberculosis and was made initially on abnormal lung confirmed at post mortem the diagnosis of asbestosis function tests and subsequently finger 4. P had tuberculosis with marked diagnosis was made after clubbing and the examination of a resected lobe Four underground workers had no suggestive ray changes B 1. complained of pain on inspiration It was one time that pleuritic pain or at least suggested at pain on limiting inspiration was a common and inspiration of asbestosis but in fact including those with other early presenting symptom only seven men out of the total mining experience complained of significant chest pain in He also developed a threatening attitude regard had to his Workers Compensation claim and this might have something to do with the eventual diagnosis but he also had finger clubbing and suggestive lung function changes l2.obe rCesehcatdednofosrigns or symptoms but the disease was found in a fairly typical tuberculosis and he subsequently developed ray changes He is operative and there is no record of whether he ever developed finger clubbing or basal yceraerpsitaafttieornwsardHsowever he is apparently alive and well some seven 3. DM complained of dyspnoeaand had basal crepitations and a few years after diagnosis was made developed typical ray changes 4. P a man with eight years underground asbestos mining complained of dyspnoea developed a deep vein thrombosis with pulmonary infarcts and a bilateral pleural effusion which by raising and fixing his diaphragm caused a tight restricted lung Post mortem following a coronary thrombosis showed a marked fibrosis tending to be both nodular and interstitial with asbestos bodies many The nodules were apparently too immature to be identified definitely as silicotic and perhaps this stage of disease as with the previous men should not be included in a survey of this type where it is obviously too young even in terms of pathology to produce diagnostic signs and symptoms This man illustrated the difficulty experienced in advising workers in this industry whether they might safely continue or not Perhaps the only medical advice one could have j Almost of pure asbestos fibre in the lower part the mill heading for the bagging section 454 in view of the dusty conditions conditions and history was If ever given - don't and If you are there - thinking of going wanted They were making you are leave but this is not the the advice they could continue to very big money and they wanted to know if they of clinical make this big money and if there were no signs disease one could not advise them to leave in It was hoped that our obvious concern for their health the diagnosis of lung disease young men after short exposures and the deaths of men they . had known would influence them This did not happen andand it was not unusual to strongly to leave diagnose disease in a man even with symptoms work and find that he in this industry refused to accept medical advice to cease Medical advice to leave was often resented andand to a advise man to leave simply on suspicion of inducsoturlidalnodtibseeamseet wians tchoeunatbesreendcebyof a demand for compensation which identifiable disease The difficulty was aggravated tootoo by the rapidity of . onset of disease where as has been described described men could proceed from nothing abnormal to grossly grossly abnormal in twelve months GENERAL OBSERVATIONS Mill workers with pneumoconiosis Year commenced Work Number affected 1940-1944 2 1945-1949 4 1950-1954 19 1955-1959 16 ~ 1960-1964 - 1965 plus Year diagnosed 1940-1944 1945-1949 1950-1954 1955-1959 1960-1964 1965 plus , Number affected - 1 - 8 24 8 Underground workers Year commenced Number work affected 1940-1944 1945-1949 1950-1954 1955-1959 1960-1964 1965 plus - ~ 17 13 1 ~ Year diagnosed 1940-1944 1945 1349 1950-1954 1955-1959 1960-1964 1965 plus Number affected - 4 12 13 The date on which the men commenced work and the year of onset of disease corresponds with thethe increased production of fibre from 1,000 to 4,000 to 15,000 tons per annum from 1950 onwards in conditions which had initially given rise to concern The bagging section There is gross fibre contamination and the respirators are obviously ineffective (" I: . vq a a! of | 4 a | " | i.on | appears 456 Although underground conditions to have been more dangerous were bad the mill More patients with acute disease after short exposures within the next year or so but the latest will probably appear in the mill was 1959 date of commencement in the diagnosed cases and underground 1960. One can hope that this reflects improved and more effective dust working conditions better ventilation extraction especially in the mill in However from personal inspection from 1959 and as Mr. Major will demonstrate even in 1966 dust concentrations in the mine and mill remained too high and one may expect after an interval of a few years new cases of the more chronic and usual type of pneumoconiosis to appear AVERAGE LENGTH OF EXPOSURE TO DUST , iy Ya | | am E Mill j I 7 No. No. " 41 Age 45 years range 24-67 Length of exposure Interval between commencement & diagnosis | 5.25 years _ range 8.4 years range 1-14 2-16 j { 4 j Fr li of 4 ; 't 4 7 Underground 29 40 years 6.6 years 9.7 years r^nge range range 29-51 3-12 5-14 . ment of The average length of exposure the disease was 5.25 years with in the mill for a range between of the underground workers 6.6 years ranging from 3-12 age being 40 to 45 years respectively develop1-14 and the average of the twenty men who had had significant dust before coming to Wittenoom the average exposure of exposure eighteen of them was 4.7 years It had been thought that previous dust exposure would make a man particularly susceptible but the effect of the previous dust burden appears to have been additive only The shortest exposure in the mill was one year only and , this produced clinical evidence of lung disease in two years Two men carting tailings on contract probably working twelve hours a day six days a week although in the open air developed disease after only two years exposure The interval between commencement of exposure and the appearance of diagnostic signs of disease was very short in a few cases very much shorter than I have ever seen described 457 DISTINCTION BETWEEN MINE AND MILL WORKERS DISTINCTIONDISTNCIO DISTINCTION BETWEEN BETWEEN WORKERS In the underground mine the asbestos vein was rarely of more than nine inches in height so that even in wa h3er9easstoipne the there was another 30 of face mainly quawratszittoe obtain a purer mill the whole purpose the operation whilst there may have been a lot of silica dust in the fibre so that the upper earlier parts of the mill the crushers and shakers final mill process involved pure fibre only Clinically it had always altth hao t au ltg houh gh asbestos workers appeared to develop silicosis asbestosis asbestosis was more important in the mill siliac ndosis licioss is in the underground workers This appears to be confirmebdy the and prevalence of finger clubbianngd basal crepitations in mill ; _ uO basal mine workers * Mill Underground No. 41 29 Finger | clubbingclubbing 16 40 ult 22 50 6 21 8 28 Basal Basal |. : creps 21 50 ult 27 60 8 28 Asbestos | bodies in sputum 18 44 8 38 9 31 Of the mill workers 50 rising to 60 had persistent basal crepitations as opposed to 28 to 31 of the underground chronic bronchitis or such workers and three mill workers had adventitious sounds as to extensive disease as to cause so many prevent one from finding crepitations if they had been present at These basal crepitations are of course common in conditions causing interstitial pulmonary fibrosis but we have found that these fine rarely coarse persistent crepitations are the most typical and convincing sign of disease in asbestos | workers In the light of our experience their presence almost = justifies the diagnosis even the absence of any other sign or symptom and if it was a matter of advising a man to leave the industry then their presence would be sufficient A careful examination must be made as they may only be heard in small localised areas Forgacs 1 recently suggested that these noises are due to miniature bangs or explosions caused by the sudden equalisation of air pressures upstream and downstream in partially deflated areas during inspiration and that these occur maximally and audibly the bases where there is an additive gravitational deflationary effect The degree of deflation can be estimated by the effect of placing the patient horizontal when the noises Right side shows the edge of a silicotic nodule and on the left side slightly power shows interstitial fibrosis and asbestos bodies diminish this out with the 459 ; or disappear I have only had the opportunity of trying on a few of these men Crepitations heard at the bases patient erect did disappear when he lay down prone ASBESTOS BODIES Forty percent of all the men had asbestos bodies in their sputum Their presence does not appear to have any special significance and half the men diagnosed had no sputum to examine An effort was made to asbestos bodies in their sputum in the town with sputum at all see whether or not but the townspeople one could be had found COUGH AND SPUTUM No. Cough Sputum Dyspnoea .Smoker .Smoker ew |} | | | 70 we Mill 41 29 71 23 55 30 73 28 e ground 29 21 73 | 14 48 | 21 73 | 22 73 ew The prevalence of persistent productive cough and dyspnoea was similar in both groups and certainly insofar as a productive cough was concerned was obviously more related to smoking habits than dust exposure or pneumoconiosis Six under- ew ground and eleven mill workers had chronic bronchitis 16 of whom smoked The smoking habits of the other were not recorded we CHEST RAYS As mentioned previously the commonest presenting nr abnormality was the chest ray ; mmr m Although 17 x 14 films were always used the quality of the films obtained from a mobile unit was variable and the mem earliest abnormal changes extremely difficult to define Perhaps there was an impression of a general slightly diminished trans- wow lucency with a fine arborisation spreading out from the hilum to the periphery but this was so often accompanied by an increase in weight with a rising diaphragm in the stocky mesomorphic : chested Italian miner so frequently employed and so suited to working conditions especially underground that it was often difficult to know whether lung disease was present or not A rather soft film in one year might make a man highly suspect while a slightly more penetrated film the following year gave a false impression of security Obviously films not in full inspiration were troublesome Probably the earliest changes Section of lung from worker under polarised light showing doubly refractile silica particles and asbestos bodies 461 . . could best be described by what used to be understood by the term reticulation proceeding fairly rapidly to a picture corresponding to the upper limit of P.3 lower limit N.3 of the International Labour Organization Classification of Radiograph 1958. The usual classical picture of asbestosis which has been described with a ground glass appearance at the bases and lower thirds of the very common lung fields and a normal upper third has not been at Wittenoom The general picture is that of silicosis and it is not unusual to find even at a late stage in the mill workers fairly clear peripheral bases The general appearance of the underground workers rays would correspond to P.2 the I.L.O. classification sometimes proceeding to A B and C shadows and none of them showed asbestosis . The mill workers rays showed a finer much more generalised change which is very difficult describe and A B and C shadows appeared Seventeen 40 had definite radiological basal asbestosis and in a few of these without again evidence of nodular disease elsewhere - Some mill workers progressed to typical N.3 nodules with A B and C shadows again PLEURAL EFFUSIONS Six men developed bilateral pleural effusions for no very apparent reason Pleural fluid examination and biopsy where performed were unremarkable Four of these subsequently developed signs of pneumoconiosis The fifth died of sub- : arachnoid haemorrhage No post mortem was done and the sixth is still being followed up Two other men developed bilateral pleural effusions following obvious clinical vein thrombosis and pulmonary infarction and later developed signs of pneumoconio- sis The raised adherent diaphragms not only produced tight lungs but by diminishing translucency at the bases caused considerable difficulty in diagnosis and eight Bilateral pleural effusion is not a very common condition in such a small series seems remarkable PLEURAL PLAQUE Pleural plaques have not been workers or townspeople the townspeople on at least two occasions e found in either were rayed on ; mine 70 mm film LUNG FUNCTION TESTS for There were no facilities at Wittenoom for routine lung . function testing Our policy certainly in the earlier years was to admit doubtful cases to hospital full investigation A number of men had quite extensive lung function tests and certainly as their disease progressed typical changes such LS? A WI - e:ech ete aa whem. * a a LL -< -< ==e e slet Seb Ter te ben AT a re sere ACS nn cane Bap e aA eats, EA menmeneSse . ee - ae te = toe = pee + = ee , a . Ba .- , > BESSR : po Re Ree = mAs Gf power view of the lung of a mill worker showing the edge of a silicostic ilicotic nodulenodule and asbestos bodies and interstitial pulmonary fibrosis 463 . was those described recently by Dr. Elder 2 occurred but in only two men with a normal vital capacity at diagnosis was a gas exchange defect demonstrated and this was minimal Twenty out of 41 66 mill workers and 21 out of 29 72 underground workers had vital capacity and forced expiratory volume one second FEV1 estimations done at or very soon after the time of diagnosis high FEV Finding a decreased vital capacity with a relatively suggested restriction and the absence of obstructive airways disease was useful supporting evidence of pneumoconiosis when other signs were equivocal : Once again the mill workers compared very unfavourably with the underground miners Ninety percent of the mill workers had a reduced vital capacity as against 62 of the underground workers Of the mill workers with a reduced vital capacity 19 70 had a forced expiratory ratio PEV x 100 above 75 and 11 above 80 Of the underground workers 13 out of 21 62 had a reduced vital capacity and 7 54 had a forced expiratory ratio above 75 ve, PATHOLOGY . . Lung sections were available from three underground and twelve mill workers nine post mortemnisx lung biopsies The significant finding has been the admixture of disease extensive interstitial pulmonary fibrosis with asbestos bodies and silica noduleansd silica particles even in mill workers could also be demonstrated - . . ASSOCIATED CONDITIONS AND PROGRESS Mill Under- ground No. 41 29 T.B. T.B. Cancer 4 12 [| lung + ** {1 1 meso- pleura 10 2 - Dead 14 34 2 % Totally { 11 27 4 19 * Diagnosed ** Developed later A single instance of lung cancer occurred in a very heavy cigarette smoker MWues MOITen Sutacys fpoq exo zo oe*SAQy Tdueg Jo 465 A pleural mesothelioma which has described 3 occurred in a man who worked to 1949 the tumour appearing in 1960 been previously in the mill from 1947 The high labour turnover has meant that very many men have been exposed to high dust concentrations for short periods but there has been too brief an interval since their exposure for lung cancers or pleural or peritoneal tumours to have 4 occurred In fact the pleural tumour described at ten years is after one of the shortest intervals described A particularly bad feature of Wittenoom was the persistent use of mine tailings for road surfacing which exposed the townspeople andchildretno loose dust containing a varying percentage of blue fibre Eight men developed pulmonary tuberculosis four with atypical mycobacteria This number is high but it is associated with silicosis and several of the men were close contacts who normally worked drank and smoked together for long hours As regards the fate of these men contrary to what is sometimes claimed in asbestosis the pneumoconiosis in - almost every instance continued to progress even after exposure to dust had ceased possibly because of the silica present The mill workers fared very badly compared to the underground workers Fourteen are dead and eleven totally disabled compared to two and four underground workers Causes of Death Mill Underground workers workers } Tuberculosis and pneumoconiosis 4622AA Pneumoconiosis . 4622AA Pleural mesothelioma 4622AA Lung cancer . 4622AA Sarcoma 4622AA Cancer of the oesophagus 4622AA Coronary thrombosis 1 f - { - ~- - ; One man returned to Italy in 1963 and has been lost _ sight of mo CONCLUSIONS ~~ It is obvious that the mine and mill were too dusty and poorly ventilated The early onset and extensive acute disease which has affected nearly everyone who stayed there long enough | must be attributed solely to the very high concentrations of finely divided siliceous and asbestos dust to which they were exposed Earlier work by Englebrecht 4 in South Africa suggested that 400 added quartz increased the fibrogenicity of crocidolite but he used cleansed extracted fibre.and later work 5 has shown that natural milled asbestos already has an optimal quartz content Medical examinations should have been done at six monthly intervals and should have included routine lung function tests with some measurement of gas diffusion me The rapidity of onset and progression of disease was continually surprising and we despaired at making an early diagnosis and at our inability to advise these men properly Most of the men were migrants to Western Australia the language problem and the isolation of the mine also increased the difficulty The men at least in the mill did try wear ment respirators but these could never have been very effective and in some ways were just a bad joke Keener interest and encouragein the use of respiratory protection would have been worth- while but the heavy work in very high temperatures would make success unlikely The causes of this tragedy were complex but a contributory factor was the dichotomy which was introduced in 1926 when the Commonwealth Government undertook the periodical examination of miners and the State Government Mines Department continued to be responsible for health safety and welfare in the mining industry . The Acts and system of medical examinations were excellent and well ahead of their time but the legislation regulations and practice in regard to dust suppression and ventilation and indeed everything regarding the health of miners was never related to the results of the medical examinations The State Health Department took over the medical examination of miners in the Mines are still 1953/1954 and despite willing operation and Health Departments the effects of this apparent ' from both dichotomy REFERENCES 1 Forgacs P. 1967 Crackles and Wheezes Lancet No. 7058 203-205 2 Elder J.L. 1967 Asbestosis in Western Australia Med J. Aust 2 No. 13 579 583 3 McNulty J.C. 1962 Malignant Pleural Mesothelioma in an Asbestos Worker Med J. Aust 2 953 4 Engelbrecht F.M. 1964 Experimental Studies on Asbestos S. Afr J. Lab Clin Med 10 45 5 Engelbrecht P.M. 1966 Experimental Studies on Asbestos Part II S. Afr Med J. 40 976-979