Document 4JKdrb4Ed6DpMwkq8Vmy7Mabx

FILE NAME Talc TALC DATE 1955 DOC TALC306 DOCUMENT DESCRIPTION Journal Article - Talc Pneumoconiosis Kleinfeld see JAJ215 BC Notes talc per se does produce a distinct fibrosing pneumoconiosis and it has been suggested that this slowly developing fibrogenic disorder may be allied to asbestosis According to McLaughlin the evidence favors that talc pneumoconiosis is caused only by the fibrous varieties of talc The asbestine variety of the talc found in our study may therefore explain the close resemblance of the ray picture to that of asbestosis It is significant that asbestos bodies first emphasized in talcosis by Gardner are almost invariably present in cases of talcosis in which talc fibers are of an appreciable length p 71 Talc Pneumoconiosis M. Kleinfeld Jacqueline Messite and 1. R. Tabershaw Arch Ind Health ~ 66-72 July 1955 Barry Castleman Comments - talc per se does produce a distinct fibrosing pneumoconiosis and it has been suggested that this slowly developing fibrogenic disorder may be allied to asbestosis According to McLaughlin the evidence favors that talc pneumoconiosis is caused only by the fibrous varieties of talc The asbestine variety of the talc found in our study may therefore explain the close resemblance of the ray picture to that of asbestosis It is significant that asbestos bodies first emphasized in talcosis by Gardner are almost invariably present in cases of talcosis in which talc fibers are of an appreciable length p 71 Talc Pneumoconiosis M. Kleinfeld Jacqueline Messite and 1. R. Tabershaw Arch Ind Health ~ 66-72 July 1955 Talc PneumoconiosPis neumoconiosis MORRIS KLEINFELD M.D. JACQUELINE MESSITE M.D. and IRVING R. TABERSHAW M.D. New York enue PABA TIAMAT MIE Since Thorel's original study in 1896,1 when talc pneumoconiosis was first recog- nized as a distinct pathologic entity numer- ous clinical and experimental reports have continued to appear in the literature The bulk of these reports have related to workers in talc mills and mines and to those engaged in the rubber industry Three investigations of the talc industry were carried out in New York State Dreessen's study of 57 men ex- posed to tremolite revealed an incidence of fibrosis above average 67 but of a non- disabling character In contrast to Drees- sen's* observations the findings of Porro Patton and Hobbs based on 15 cases with 5 postmortem examinations showed that pneumoconiosis causing disability and death does occur in talc workers and that patho- logical tissue changes are principally due to talc itself In 1943 Siegal Smith and Green- burg "" reported on the dust hazard in tremo- lite talc mining including roentgenologic findings in tale workers and their findings and conclusions were similar to those of the latter Since the roentgenograms and histories of the 32 cases reported on by Siegal and asso- ciates 6 were still available after 14 years a follow study was undertaken in order to 1 ascertain the health status of this group 2 evaluate the present operations and dust concentrations of the talc mines and mills Recorded for publication April From Division of Industrial York State Department of Labor * References 2 and 3 6 1955 Hygiene References 4 to 6 New 66 and 3 do comparative study of the workers employed before and after the newer engineering techniques had been introduced 1943 The present paper deals largely with the first two objectives the third is now in progress and will be reported at a later date FINDINGS Environmental Data study of the operations and dust concentrations of the talc mills and mines at this time shows a marked improvement in the engineering techniques from that found in 1941 and this is reflected in an appreciable decrease in the dust exposure From 1943 to 1948 a number of corrective measures were insti- tuted to reduce the dust concentrations and included the following a wet drilling in mines; b enclosure of elevator and chutes c installation of automatic bagging machines d conveyorized car loading e discontinuance of blow rooms and f pro- vision of local exhaust ventilation The dust concentrations obtained at the mills before and after improvements were instituted are summarized in Table 1 Medical Deceased Of the original 32 patients 19 have since died and the causes of death obtained from the hospital records physicians files or death certificates are given in Table 2. No necropsy data are available to confirm the clinical diagnosis The ages of the 19 that died ranged from 48 to 84 years and in the 4 whose cause of death was believed to be due to pulmonary failure associated with talc pneumoconiosis the ages varied between 60 and 79 years Living Thirteen of the original 32 are still alive and of these 7 have retired and 6 are gainfully employed The ages of the re- tired group vary between 63 and 83 years the ages of the actively employed between TALC PNEUMOCON TABLE Compara = e < ee Compara Drilling Mucking . General air wo... Mills Crushing .........0.., Garners and separator Bagging ............., Open chutes ......... air General .........., * Dust counts are in mill High count due to leak Patient Age Yr L A. Unknown B. 63 W. 84 - D. 53 B. 60 A. Unknown Fra Card 1 2 (1) @) 1 2 Unk K. H. V. 68 56 Unknown * Causes of death were { : 8 death certificates 45 and 64 years A su the clinical and laborat in Table 3 COMM In view of the comp ber comprising this ins t cance can be attached deceased and living gro however that the age workers was between that in the four dece death was believed to insufficiency associated ages varied between 6 though no statistically data can be formulated of tremolite talc expos is of interest that an al Material may be protected by copyright law Title 17 U.S. Code omparative of omparative study of the work-work- before and after the newer chniques chniques chniques had been introduced introduced introduced present paper deals largely two two objectives tthe he ththiirrd d is ss and will be reported at a FINDINGS of tal Data study of 1 dust concentrations of the the mines at this time shows a in engineering A ovement in the engineering 1941 and found in n tthat hat found in 1941 this and this an appreciable decrease in sure From From 1943 to 1948 a rrective rrective measures measures were insti- insti- insti- e the dust concentrations concentrations concentrations concentrations and ollowing : a wet drilling in elevator closure of elevator and chutes ; on of automatic onveyorized onveyorized onveyorized car bagging loading loading ma- e e of blow rooms and pro- exhaust ventilation The dust obtained at the mills before rovements were instituted are 1 Table 1 ta Deceased Of the original 19 have since died and the th obtained from the hospital cians files or death certificates Table 2. No necropsy data are onfirm the clinical diagnosis the 19 that died ranged from , and in the 4 whose cause of ieved to be due to pulmonary ted with talc pneumoconiosis d between 60 and 79 years irteen of the original 32 are of these 7 have retired and 6 employed The ages of the re- ary between 63 and 83 years e actively employed between TALC PNEUMOCONIOSIS TABLE Comparative Dust Count Data at Several New York State Talc Mines and Mills Original Study 1941 Low Mines DrillinDrgil ing . oc cccececceseeeseeeeeeneee Mucking wee seen ne ccccse eee e cee e ee General air oo... cece cece cece ene eee 83 2 4 Medium High 413 2,800 36 475 18 36 Average 818 120 19 Mills Crushing Screening Grinding mills .... Garners and separators . Bagging v.eeeeeeeeeeess Blow room oo... Open chutes .......... General air .......ccsseceeeeeeeeee 22 69 690 180 43 32 136 69 32 75 271 92 58 70 728 278 26 129 520 151 1,196 2,480 1,227 21 83 440 125 65 70 85 69 Follow Study 1954 - Low Medium High Average 0 2 S 3 3 4 5 4 a : ae oe 6000 13 360 6000 35 68 5 15 40 LOCO 21 5 16 90 Discontinued Discontinued 5 18 40 63 + 8538 20 8538 23 19 * Dust counts are in million particles per cubic foot High count due to leakage from conveyor enclosure TABLE Causes of Death in Talc Pneumoconiosis - Patient Age Yr L. A. Unknown B. 63 W. 84 D. 53 F. 60 A. G. J. K. L. V. Unknown 68 68 56 Unknown * Cause of Death Fractured skull Carcinoma of G.I. tract 1 Hypertensive cardiovascular disease 2 Cerebral hemorrhage 1 Cerebral hemorrhage 2 General arteriosclerosis 1 Pulmonary insuffleiency pneumoconiosis 2 Congestive heart failure Unknown Acute myocardial infarction Acute myocardial infarction Acute myocardial infarction Mesothelioma of pleura moconiosis bilateral Patient L. L. J. M. Age Yr 62 57 65 W. 68 W. O. 48 Cause of * Death Acute myocardial infarction Carcinoma of stomach Carcinoma of pancreas es Pulmonary failure associated with pneumoconiosis Duodenal ulcer L. S. 72 R. S. 79 T. C. Unknown 58 Pulmonary failure due to pneumoconiosis 1 2 PnMeyuocmaorcdoitniisosis Unknown Carcinoma of G.I. tract * Causes of death 3 death certificates were obtained from the following following sources 1 private private physicians physicians 2 hospital hospital records records and 45 and 64 years A summary and analysis of the clinical and laboratory findings are seen in Table 3 COMMENT In view of the comparatively small number comprising this investigation no signifi- cance can be attached to age incidence of the deceased and living groups Itis noteworthy however that the age range in the retired workers was between 63 and 83 years and that in the four deceased whose cause of death was believed to be due to pulmonary insufficiency associated with talcosis the ages varied between 60 and 79 years Al- though no statistically significant correlative data can be formulated between the duration of tremolite talc exposure and longevity it is of interest that an above average life span may occur following prolonged exposure to talc dust and associated with pulmonary dysfunction Tables 2 and 3 Analysis of the medical data of the living shows many similarities to those reported in the literature Clinically the outstanding features are dyspnea productive cough abnormal chest findings diminished breath sounds basal rales limited chest expansion clubbing and a roentgenographic picture descriptive of pneumoconiosis Clinically the course is relatively slow but progressiveand similar to silicosis the clinical picture does not retrogress with marked improvement of the industrial environment or upon retire- ment Dyspnea is present in 100 of the group and is sufficiently pronounced to limit = References 5 to 7 Material may be protected by copyright law Title 17 U.S. Code TABLE Symptomatology of Talc Pneumoconiosis Clinical Picture Patient F. Symptoms + one Coen Age Environmental Yr Status Exposure Yr . DyspCough nea 63 R Tale mill { Mi S P Signs + = Lungs Br sounds distant Rales basal Emphysematous Heart Enl Roentgenologic Findings ro Clubbing Progres- sion Compli- cations ~ Plaques + S S Bullae Pr Cor pulmonale EKG Rt.V.H. pattern Peripheral Blood co Hgb RBC WBC Diff 15.5 5.15 9.1 N M. G. 64 W Tale mill None Mi Br sounds distant Not None Mi Hilar nodes Pr Normal 15 5.16 11.1 N Materil Aluminum Emphysematous enl W. H. 49 W Tale mill Steel mill 100 Ja Clear to palpation Not Mi Ja and auscultation enl J. J. 49 W Tale mill sa sa S Br sounds distant Enl S Rales throughout enl Mo Hilar nodes Pr enl S Cor pulmonale Pr ueeeeeeee 16.5 5.28 8.6 N Rt.V.H. pattern 16.5 5.21 13.8 N Emphysematous may W enl R. J. 59 Tale mill $ Mi Mi Rales and wheezes Not Mo P throughout Mi None be 83 C. K. R Tale mill S 02 Br sounds distant Not Mi P Rales throughout enl Mo None Not pr Pr naseeeeee 15 5.01 11.8 N Abnormal 15.5 5.09 rhythm 9.8 N Emphysematous V. 45 S S W Tale mine { Mo P Br sounds distant Not None Rales basal enl Emphysematous Bullae Pr Hilar nodes enl protecd S. P. 63 R Tale mine 119 Br sounds distant Not Mi Mo None Pr Talc mill 119 Rales basal enl by Zinc mine Emphysematous Normal 16 5.12 7.1 N Lt.V.H. pattern 16.5 5.2 7.8 N G. S. 73 R Tale mill Mi Mo Br sounds distant Not None Mo None Pr Normal 16 5.18 9.1 N . Other quarries P Rales basal enl copyright -17 W. 69 R Tale and zinc mines Emphysematous Enl S Pr Mi S Br sounds distant Mo Hilar nodes P Rales throughout enl Emphysematous Lt.V.H. pattern 14.2 4.61 8.8 N law 02 S. W. 63 W Tale mill Mo P Br sounds distant Not Mi Rales throughout enl Emphysematous Mo Bullae Pr Nonspecific 14.4 4.71 13.1 N wave changes B. M. 79 R Tale mill $ Mo Mo Emphysematous P Rales basal T1it7le R eennll enl R. 79 Tale mill $ None Mi Rales basal Not Mi Not Mi Mo Hilar nodes Pr enl Mi Hilar nodes Pr cavseeaee lee eee eee 12.2 3.5 10.2 Baso- philes % U.S. * Status Retired Working Minimal Moderate Severe Productive Present # Exposure to tale only Code the worker TALC TALC the Of the TALC 1954 B. chest Of worker ordinary 1954 extreme worker ordinary tersialFig infltraion chest note extrem M. extreme ordinary note a - ordinary 1A rays moderate 1954 PNEUMOCIS extreme moderate rays routine rays moderate routine 2. . interest moderate routine infltraion routine interest moderate interest routine infltraion interest Patient routine 1A 1A , giant Patient pericadlPatien ibasnicterest bulla and B. PNEUMOCIS basic and of degr physic basic degr v basic are degr physic basic are S. S. R Baso- philes% 13.1 10.2 4.71 3.5 12.2 14.4 12.2 patern Nonspecifwavechanges Pr Pr Pr nodes nodes enl Bulae Hilar enl Hilar enl Mo Mo Mi Mi Mi Mi Not em, Not enl. Not en] Emphyseatou Emphyseatou Emphyseatouthrougt througtdistant sounds Rales basal basal Rales Br Rales Emphysematous Rales Rales Presnt Pr Mo Mo Mi Productive MoP None $ f 25 51 mil mil Sevre mines Tale Tale S Working M R only Moderat 63 Retired tale to Minmal W. Staus Exposure * +* TALC PNEUMOCONIOSIS Fone : Fig Patient S. W. 1941 characteristic basal infiltrations are seen B Patient S. W. 1954 note giant bulla in R. U. and prominent hilar markings the ordinary routine physical activity of the worker to a moderate degree Of extreme interest are the findings in the chest rays The basic lesion is an in- terstitial infiltration of variable intensity located basally and in the midlung fields and of bilateral distribution with the apices relatively spared In several the infiltration is nodular in character Emphysematous bullae of varying sizes are observed in four Fig 2.A Fig B. Patient B. M. 1941 pericardial and diaphragmatic plaques are seen B Patient B. M. 1954 pericardial and diaphragmatic plaques are more pronounced Material may be protected by copyright law Title 17 U.S. Code A. M. A. ARCHIVES OF INDUSTRIAL HEALTH 1A and B A most striking finding is the presence of opaque densities varying from single linear strands in the region of the diaphragm to massive deposits bizarre in shape extending over a large part of the lung field and occasionally on the pericardium Fig 2A and B These deposits referred to as talc plaques by Siegal and associates are observed in all but one of the cases studied Cardiac enlargement is pres- ent in four persons in two of whom the cardiac configuration is suggestive of cor 1941. As mentioned previously two of the present chest rays showed cardiac con- figurations suggestive of cor pulmonale but of even added significance a markedly de- creased cardiac silhouette is noted in one pa- tient G. S. and is strongly suggestive in another The cause for this is not clear It is possible that pleural pericardial adhesions associated with the plaque formation and subsequent retraction and limitation of the pericardium may possibly account for this decreased cardiac silhouette Seo ina sie eo Fig 3. Patient J. J. 1941 progressive infiltration extending picture is one of cor pulmonale marked basal infiltrations are noted to upper lobes is seen there is a B Patient J. J. 1954 dilated heart clinical pulmonale The pulmonary arteries and branches are prominent in a number of the chest rays When comparisons are made with the roentgenograms taken in 1941 it is of interest to note that although variable progression occurred in the majority of the patients Fig 3A and B the most outstanding revelation is that what in retrospect had appeared to be severe pulmonary involvement in the original series cannot be so considered in the light of a year interval Furthermore the hilar adenopathy which is seen in six of the present series in retrospect was also present in three of the rays in 70 No correlation between symptomatology and ray findings is noted and this has been observed by others. Although the series is small there appears nevertheless a trend between the degree of clubbing and chest ray involvement those with severer clubbing show more extensive pulmonary in- volvement Six out of 11 show abnormal electrocardio- graphic configurations such as a pattern of right ventricular hypertrophy 2 b pattern of left ventricular hypertrophy 2 References 6 and 8 TALC PNEUMOCONIO c abnormal rhythm specific wave alteration suggestive trend betweel normal electrocardiogra five whose electrocardio only one shows clubbing mal degree; in the six wit cardiograms clubbing va ate to a marked degree the two with the right trophy pattern It is not latter two the clinical pict of cor pulmonale The in in tremolite pneumocon however histologic evide eral investigators confi relationship Jaques and reported not only genera all the pulmonary arterie largement associated wit monary talcosis but als involvement of myocardi of the paucity of the av data on human pulmonary anism underlying the d pulmonale is not clearly The peripheral blood f markable and indicate t blood does not reflect th changes associated with ta The workers presently developed and well nouri the observations made by ciates and no reason cai plain this apparent differ The results of the pre the findings of other inv a. per se does produce pneumoconiosis and it h that this slowly developi order may be allied to as ing to McLaughlin the e talc pneumoconiosis is c fibrous varieties of talc T of the talc found in our st explain the close resembl picture to that of asbestos that asbestos bodies fir talcosis by Gardner are present in cases of talcos Material may be protected by copyright law Title 17 U.S. Code OF INDUSTRIAL HEALTH tioned previously two of the rays showed cardiac con- gestive of cor pulmonale but significance a markedly de- silhouette is noted in one pa- and is strongly suggestive in cause for this is not clear It pleural pericardial adhesions a the plaque formation and raction and limitation of the ay possibly account for this iac silhouette noted B Patient J. J. 1954 e is a dilated heart clinical ion between symptomatology dings is noted and this has 1 by others. Although the , there appears nevertheless a 1 the degree of clubbing and volvement those with severer more extensive pulmonary in- 1 show abnormal electrocardio- gurations such as a pattern ricular hypertrophy 2 b ventricular hypertrophy 2 6 and 8 TALC PNEUMOCONIOSIS c abnormal rhythm 1 and d nonspecific wave alterations 1 There is a suggestive trend between clubbing and abnormal electrocardiographic findings In five whose electrocardiograms are normal only one shows clubbing and this to a mini- mal degree in the six with abnormal electrocardiograms clubbing varies from a moderate to a marked degree being severest in the two with the right ventricular hypertrophy pattern It is noteworthy that in the latter two the clinical picture is characteristic of cor pulmonale The incidence of the latter in tremolite pneumoconiosis is unknown however histologic evidence reported by several investigators confirms an etiological relationship Jaques and Benirschke have reported not only generalized thickening of all the pulmonary arteries with cardiac enlargement associated with progressive pulmonary talcosis but also a granulomatous involvement of myocardium per se In view of the paucity of the available pathological data on human pulmonary talcosis the mechanism underlying the development of cor pulmonale is not clearly defined The peripheral blood findings are not remarkable and indicate that the peripheral blood does not reflect the physiopathologic changes associated with talc pneumoconiosis The workers presently observed are well developed and well nourished in contrast to the observations made by Siegal and associates and no reason can be offered to explain this apparent difference The results of the present study confirm the findings of other investigators that talc per se does produce a distinct fibrosing pneumoconiosis and it has been suggested that this slowly developing fibrogenic dis- order may be allied to asbestosis.10 Accord- ing to McLaughlin the evidence favors that talc pneumoconiosis is caused only by the fibrous varieties of talc The asbestine variety of the tale found in our study may therefore explain the close resemblance of the ray picture to that of asbestosis It is significant that asbestos bodies first emphasized in talcosis by Gardner are almost invariably present in cases of talcosis in which talc fi- bers are of an appreciable length.10 This has been observed histologically by several investigators ' and by ourselves In essence this pneumoconiosis consists of a dense fibrosis which is particularly prevalent peribronchially and perivascularly and occurs in sheets occasionally assuming a nodular configuration the latter finding has been suggested as representing a reaction to the quartz content of the talc The hilar lymph nodes are generally described as showing no enlargement or fibrosis and on microscopic examination they are reported to contain talcladen macrophages and the tale content to be of considerable magnitude ; It is appreciated that some of the workers may have been exposed to a relatively high concentration of quartz at some phase of their operation but it appears highly unlikely that this was uniformly present for all the workers particularly in view of the consistent finding of low free silica content in both the mills and the mines Furthermore evidence has been presented by recent investigators / that moderately advanced pneumoconiosis is caused by talc in the absence of any silica in the talc mixture or in the atmosphere It is not unlikely that some of the commercial preparations of tale which have different mineralogic and chemical characteristics as pointed out by Hogue and Mallette may require a long exposure be- fore chest ray evidence or symptoms ap- pear From observations of Siegal and associates 10 years are required between ex- posure and onset of symptoms What the specific factors are in the causation of talc pneumoconiosis are not known There is need for more epidemiologic studies where environmental conditions are well con- trolled and the life course of the worker is closely followed This would permit a better statistical analysis of data than is now possible There is also a need for further experi- mental and biochemical research in this field and it is more than likely that the utilization of all three approaches will lead to the estab- || Kleinfeld M Unpublished data from personal observation { References 9 and 10 71 Material may be protected by copyright law Title 17 U.S. Code ARCHIVES OF INDUSTRIAL HEALTH lishment of better defined criteria and a clearer understanding of the mechanism and pathogenesis of talc pneumoconiosis SUMMARY AND CONCLUSIONS The health status of a group of 32 talc workers whose roentgenograms and histories were available after 14 years were restudied and the following data were ob- tained 1. Nineteen of this group had died their ages at death varied between 48 and 84 years In four whose death was believed due to pul- monary failure associated with talc pneu- moconiosis the ages varied between 60 and 79 years Of the living six are gainfully employed 2. The outstanding clinical features involve the pulmonary and cardiovascular systems Dyspnea and cough are frequent Emphysema basal rales diminished chest expansion and clubbing are the striking physical findings 3. The characteristic chest ray is that of a diffuse infiltration of the basal and midlung fields with occasional nodularities seen Emphysematous bullae hilar adenopathy and cor pulmonale are not infrequent Talc plaques located in the region of the diaphragm pericardium and extending over a large part of the lung field are consistently observed but do not reflect the degree of pulmonary involvement Likewise no correlation between symptomatology and ray findings is observed 4. Abnormal electrocardiograms are seen in six and include patterns of right ventricular hypertrophy two and left ventricular hypertrophy two abnormal rhythm one and nonspecific wave alterations one The two persons demonstrating a right ventricular hypertrophy pattern had other features suggestive of cor pulmonale There is a suggestive trend between degree of clubbing and abnormal electrocardiographic findings 5. The peripheral blood findings are not remarkable and do not reflect the changes in the pathophysiology of this disorder 72 72 6. In general the workers appear well developed and well nourished in contrast to observations reported in 1941 Although progression was observed in all the clinical course is relatively slow and in spite of the presence of moderate infiltration and pulmonary dysfunction six of the workers are still actively employed The marked improvement in engineering methods is reflected in an appreciable decrease in the dust exposure The pathological picture however did not retrogress with _ improvement of the industrial environment or upon retirement Assistance was rendered in the present study by Dr. Jesse R. Patton of Ogdensburg N. Y. by Mr. John Kean Superintendent and Miss J. Bishop of the Ray Department of Edward Noble Hospital Gouverneur N. Y. and by our Industrial Hygiene Engineering Unit REFERENCES 1. Thorel .: Die Specksteinlunge Beitr path Anat 20:85 1896 2. Marshall G. and Perry K. M Dis Chest London 262 1952 3. McLaughlin A. .: Cited by Doig A. .: Other Lung Diseases Due to Dust Postgrad Med J. 639-649 Dec. 1949 4. Dreessen W. .: Effects of Dusts on the Lungs J. Indust Certain Silicate Hyg 66-78 March 1933 5. Porro F. W Patton J. R. and Hobbs A. A Pneumoconiosis in the Talc Industry Am J. Roentgenol 507-524 April 1942 6. Siegal W Smith A. R. and Greenburg .: Dust Hazard in Tremolite Talc Mining Including Roentgenological Findings in Talc Workers Am J. Roentgenol 11-29 Jan. 1943 7. Mann B. and Deasy J. B Talc Pneumo- coniosis in the Textile Industry Brit M. J. 1460- 1461 Dec. 18 1954 8. Dreessen W. C. and Dalla Valle J. M Effects of Exposure to Dust in Two Georgia Talc Mills and Mines Pub Health Rep 131-143 Feb. 1935 9. Jaques W. E. monary Talcosis with and Benirschke K PulInvolvement of the Stomach and the Heart A. M. A. Arch Indust Hyg 451-463 May 1952 10. McLaughlin A. I. G Rogers E. and Dun- ham K. .: Talc Pneumoconiosis Brit J. Indust Med 184-194 July 1949 11. Hogue W. L. Jr. and Mallette F. .: A Study of Workers Exposed to Talc and Other Dusting Compounds in the Rubber Industry J. Indust Hyg & Toxicol 359-364 Nov. 1949 PneumoconiPo neumoconio South India _ GEOFFREY E. FFRENCH M. Oakville Ont Canada HULSE ALTA TT INTRODUCTI Pneumoconiosis has be condition in the Kolar 19410940 and continues to be only because up to now a be considerable dust ret lungs of underground wor of 10 to 10 10 15 years little countered It does not itself as a clinical disease of the word but rather as dition The potential dange dange - with tuberculosis which later The type of mining c c Kolar Gold Field require working of quartz The reefs varying from a few width which dip at a sha considerable length of time depths down to 9900 ft aannd d are being worked A dry-ddry-rdry-y- and bulb tempera tthehe the use of water dust cluded The quartz reef : ing widths of lode matter Recorded for publication Formerly Senior Kolar Gold Field Assista * The Kolar Field is border of Mysore State South 57 N. and 78 18 E. at he sea level Material may be protected by copyright law Title 17 U.S. Code