Document bB2yZNODR8jkj0kqXbvJQk14k

FILE NAME Talc TALC DATE 1943 DOC TALC004 DOCUMENT DESCRIPTION Medical Journal Article - Dust Hazard in Tremolite Mining LARY 1943 iate Proniversity we might ring par- organized no means New York done very organized our State upon the if I were e various side of our est of this ll sense of ' things for dals but I lone all of ne them so n back of it I to the fact an born on orn on the : had to go only a professional eat pleasure e American Harrington Fou. 49 No. F THE DUST HAZARD IN TREMOLITE TALC MINING INCLUDING ROENTGENOLOGICAL FINDINGS IN TALC WORKERS By WILLIAM SIEGAL ADELAIDE ROSS SMITH and LEONARD GREENBURG From the Division of Tuberculosis New York State Department of Health and the Division of Industrial Hygiene New York State Department of Labor FROM time to time the attention of the Division of Industrial Hygiene has been drawn through compensation claims to incapacitating fibrosis in talc workers Since silicate dusts of which talc is one have been considered relatively innocuous in the opinion of most authorities the single exception being asbestos the occurrence of these cases has naturally raised several questions obvious question as to whether this incapacity has resulted from talc exposure alone and the second more interesting question as to whether industrial hygienists with few exceptions have erred in considering asbestos to be the only injurious silicate dust In an attempt to answer these questions the study here reported was undertaken It consisted of an investigation of the talc industry and an examination of tale miners and mill workers in northern New York State St. Lawrence County made in 1940-1941 as a joint enterprise of the Division of Industrial Hygiene of the State Department of Labor and the Division of Tuberculosis of the State Department of Health NATURE OF TALC Talc is a hydrous magnesium silicate with the formula H M comg posed according to Ladoo,,of about 63 per cent SiO2 32 per cent MgO and 5 per cent H IOt is usually a secondary mineral re- sulting from the alteration of other mag- nesium silicates or carbonates While its own silica is present in the combined form most talcs mined commercially contain varying amounts of such impurities as quartz calcite dolomite iron oxide etc. Tale has a characteristic soapy feeling and a pearly lustre It may be pure white silvery white gray or green and when impure yellow brown or reddish The most common commercial variety is a massive foliated or granular type but it may also occur in a micaceous or in a fibrous form Soapstone is a closely related substance being essentially an impure talc and when pulverized it may be used for the same purposes Tremolite which is a calcium magnesium silicate changes over to talc It may be mined with it and subsequently ground and sold as talc GEOGRAPHICAL DISTRIBUTION The United States produces about 65 per cent of the world's supply of talc the leading states in its production being Vermont New York California North Carolina and Georgia THE INDUSTRIAL USES OF TALC According to the Minerals Year Book 1938 of the United States Bureau of Mines the use of talc and soapstone is steadily increasing Ladoo states that at least 60 different uses for talc have been noted though most of them are of minor importance Its value depends chiefly on its usefulness as a filler inert extender dusting powder and absorbent In 1921 according to Ladoo the marketed ground talc production in this country was industrially distributed as follows paper 38 per cent paint 23 per cent prepared roofing 18 per cent rubber 9.5 per cent textiles 4 per cent toilet powder 2.5 per cent other uses 5 per cent Siegal Adelaide Ross Smith and Leonard Greenburg JANUARY 1943 12 William talc is eight weeks No significant tissue changes were The other uses for which ground seen a filler in soap in foundry adapted are as in compounds Bethuneinin 1935 was able to produce pleural by blowing commer- in adhesions cats and dogs Miller and facings in insulating textiles cavity Miller adhesions dry lubricants as a filler in cotton cial talc into the pleural found that in the dressing and manufacture of leather leather Sayers quoted bei lnj oewcting adhesions dusts into polishing cleaning cleaning and manufacture agent for rice were produced by injecting various such adhesions as a coffee beans in making makinmg aking etc the peritoneal cavity but that behavior of peas peas , coffee beans not related to the subsequent peanuts windowshade colored crayons as a filler filler were a dusting agent in making candy the dust having observed granulo- = cloth as ingredient of Fienberg in 1937 of talc experimented chewing gum etc and as an mas from the surgical use mice and insecticides concrete plastics and with the injection of this substance in these Since 1921 there has been a marked in- obtained subcutaneous granulomas in in its use in the ceramic industry animals animals i crease thousand more tons of talc and Miller and Sayers in 1936 reported studies talc included Fourteen sold in 1937 than in which talc included was included among among thedusts dusts | related materials were this of this increased in which intraperitoneal reaction in guinea pigs intraperitoneal 1936 and about 10,000 tons where whose found that it produced an amount went to the ceramicceramic induindusstrytry where was studied They is the injected } amount chiefly the constituent of glazed used as constituent of glazedglazed inert reaction That to say did it initiate a talc is chiefly dust was not absorbed neither wall tile In the signifi- interpreting cellular proliferation OF the authors conclude OF LITERATURE ON THE EFFECTS cance of inert reactions REVIEW DUST that such dusts should be considered as poten- TALC TALC DUST Experimental harmful Studies During the last tally summarizing experimental work on Gardner Laboratory said a certain amount of experimental ten years has been reported but silicate dusts at the Saranac Laboratory Symposium Fourth work with talc dust of the in- at the Saranac few silicates like true on reviewing this literature most on Silicosis 1939 have are found to have minerals halation experiments tale and some of the clay of the lungs provoked been of insufficient duration to be helpful chronic inflammation after in regard to the probable effect of long con- but this reaction has tended to retrogress of to a stage industrial industrial tinued several months No progression B tinued industrial exposure fibrosis has been observed within periods In 1931 Haynes included talc in a series of guinea pigs true and there is no indication of one to two years will occur dusts studied for their reactions on were dusted two hours daily except Twelve pigs no that the progression an experiment in Policard in 1939 reported in- Sunday for a fortnight The author saw which he dusted white rats with foliated sign of pulmonary damage but found that removal occurred un- dustrial talc three hours a day for twelve days of the exposure was high He bronchial and lymHpehatciocncludes that the sub- The intensity irritating to the upper usually briskly talc are of a low degree found that the dust was a marked dysp- stances dissolved from obnoxious to neigh- respiratory tract and producesdacrificed two and of toxicity but sufficientlythe removal of cells nea In the lungs of animals he found dilata- boring tissues to cause six days after inhalation began and exuda- containing them the cellular re tion of bronchi acute emphysema Many animals died spontane- St^...berin 1934 studying of lymph nodes to various dust sus- tive alveolitis and foci of with pulmonary congestion sponse introduced into the lymphatics found ously The short duration of the pensions bronchopneumonia that tale caused no apparent cellular prolifera- tion within the lymph nodes after five days reported After 108 days the nodes were still normal and granulomatous showed no increase in connective tissue peritoneal Fossel in 1935 reported experiments in which guinea pigs were exposed to the inhalation of tale for one hour daily over a period of did not permit any conclusion con- ecxeprenirnigmetnhtes possibility of pulmonary fibrosis McCormick and Ramsey in 1941 in- postoperative tale in 2 cases flammation caused by intra- Schulz and Williams in 1942 injected VOL 49 peritoni comme nate ral ranging cases 1 holding cytic c type P fibrosis and lim terial develop contain and trei Clini cupatio this co and u Dalla talc wc Polic question the hur time a lished t tion of t of forty years in Thorel taining of certa tions m accumu nodular present of tuber In 19 stated t gerated opinion Zanel the conc to the fa dangero moconic Mere rubber t two yea ANUARY 143 anges were uce pleural g commerMiller and adhesions dusts into adhesions chavior of d granulo- erimented mice and in these ted studies the dusts umea pigs oduced an we injected initiate a the signifi s conclude as poten tal work on atory sand Symposium s like the erals have the lungs gress after after a stage of hin periods ' indication periment in olated inwelve days high He the upper arked dysp dysp ed two and and dilataand exuda| spontaneand foci of ation of the clusion con- iry fibrosis 41 reported matous in- ected intra- The Dust Hazard in Tremolite Talc Mining 13 , No. Citoneally talcs with pigs in guinea a series of seven Citoneally different silicate ratios Animals were sacrificed at intervals from ten days to fifteen months In all anging the pathological histology showed the , holding of talc particles in a focal area by phago- cytic cells of the macrophage and giant cell type Progressive fibrosis was not found The ibrosis which occurred was only enough to hold and limit the space for storing the foreign ma- terial The greatest amount of fibrous tissue developed in the presence of the two tales which contained the least carbonate and the most talc and tremolite respectively Clinical Reports Talc fibrosis as an oc- cupational disease has received attention in this country only within the past ten years and until the studies of Dreessen and " Dalla discussed later extremely few talc workers had been studied anywhere Policard says that it was in 1896 that the question of the action of industrial tale dust on the human lung was first considered At that time a pathologist of Nuremberg Thorel pullished the results of the pathological examination of the lung of a tuberculous woman patient of forty years who had worked for many years in soapstone dust According to Policard Thorel demonstrated the presence of cells containing soapstone dust in the cavity and walls of certain alveoli and the existence of formations more or less nodular resulting from the accumulation of cells filled with tale Other nodular formations of a tuberculous nature were present and Thorel pointed out a combination of tuberculous and pneumoconiotic lesions In 1915 according to Policard Hayburst stated that work in tale dust favored and exag- gerated tuberculosis but the basis for this opinion is not known Zanelli in 1931 quoted by Teleky came to the conclusion that tale dust though belonging to the family ofsilicates ought to be considered dangerous and likely to produce typical pneu- moconiotic lesions Merewether in 1933 reported the cases of 11 rubber tire workers exposed from ten to thirtytwo years to French chalk a fine granular * Since this report was written Porro F. W. Patton J. R. and Hobbs A A. Jr. Pneumoconiosis in the calc industry Am J. ROENTGENOL & RAD THERAPY April 1942 47 507-524 have described pneumoconiosis in 15 tremolite talc workers with a fatal termination in five variety of talc dust who showed diffuse interstitial fibrosis by roentgen examination without clinical evidence of anything more than a peribronchial increase in fibrous tissue Thirteen additional workers with exposures of from four and half months to eight years were examined and reported upon the following year,, confirming the original findings In 1933 a report was made by Dreessenof examinations ofa number of workers in silicate dusts including 57 men exposed to tremolite a hydrous calcium magnesium silicate containing no free silica The findings in this group were as follows more fibrosis than usual 67 per cent first stage pneumoconiosis 26 per cent second stage pneumoconiosis 2 per cent normal lungs 5 per cent Dreessen described the first stage pneumo- comosis as similar to that produced by cement dust softer than that resulting from silica dust a diffuse fine generalized fibrosis ... ... chiefly confined to the lower thirds of the lung fields In 1935 the same author together with Dalla reported on the effect of exposure to dust in two Georgia tale mills and mines The dust involved was agam a calcium magnesium silicate containing no free silica It was present in excessive amounts over one and onehalf billion particles per cubic foot in some operations the particle size averaging less than 1 micron Sixty workers were examined Among these 22 33 per cent showed pneumoconiosis 8 in stages two or three The conclusion was reached that exposure to tal^ dust was either too severe in the Georgia study or that this tale was a more dangerous dust than that previously studied No particular relationship between talc exposure and tuberculosis was demonstrated Middleton in 1936 referred to an unpub lished case of Cunningham's in which pneumoconiosis was found in a tale grinder who had been employed for nine years He also mentioned an autopsy by Sand in 1910 on a woman exposed to tale dust in which not much re- action was found In 1938 Nuck and Szczepanski,, reviewed the literature on talc fibrosis and added several cases of their own They concluded that this type of pneumoconiosis resembled asbestosis more than silicosis At the International Conference on Silicosis and Leonard Greenburg Javwants 1945 Adelaide Ross Smith William William Greenburg JANUARY 14 Smith and Leonard Greenburg JANUARY 1943 the Adelaide Greenburg Greenburg Greenburg JANUARY reported two at at Geneva Genevaiexaminnation Rexiaminatdion doefllRiddell reported results engaged engaged CASE CASE Aged forty four twenty years years CASE Aged had worked a bed laster two of the the workers grinding talc Thirteen years the claimant shoes were manufac- " grinding sembling sembling occasion said that of the tured tured factory factory White months of manufac- manufac- months at these during about dusting and Gardner Gardner on workers occasion occasion that films of workers he examined 300 evidence he used freely dusting no the shoes soiling the white leather The powder prevent 300 50showed showed about about suggested pulmonary of Industrial contain Division no reaction reaction which in . . literature appears silica silica Hygiene and faonudnidn contain no years before survey of literature com- that From survey studies appears For seven work experimental dyspnea hitherto while clinical have plamed of cough His have hitherto incionndcilcuasteivethat talc dust studies of necessitated necessitated hospital treatment finally showed of the fingers. capable capable tended examination producing capable injurious pulmonary Physical showed presence presence on changes cyanosis and clubbing fingers . dyspneaof lungs the changes DUE Examination Examination CLAIMS FOR DISABILITY TALC YORK STATE sides fremitus fremitus breath breath examination showed which IN NEW Roentgen examination chest showed The cases at- Roentgen of mottling showed nodular nodular ven- Industrial Hy- densities confluent The nodular giene to Divisionoriginally disability tricle distributed ven- tgiene from exposure was hypertrophied hypertrophied cor pulmonale resulting to talc dustare below Six diagnosis hypertrophied chronic pulmonary fibrosis fatally summarized such such cases have originated One during the past emphysema emphysema terminated fatally fibrosis months emphysema The terminated hospital hospital had admission few years powder talcum one the manuthe shoe shoe III Aged forty The claimant forty nine facture facture talc years industry and them and worked talc talc with fifteen fifteen with industry case Case Case v mining months exposure exposure milling one one probably significant significant previous exposure exposure there eight dust dust Five talc exposure exposure other began breat pyeraersviboefuosre death exposure Hisshiortnless lbnreeatshsbreath two cases containing free summaries summaries the and shortness productive productive productive two of available fatal cases are summariesare years the onset symptoms symptoms because because to a follows available CASE as folfollowosws CASE : 5 anceasse,s) 0 weakness after weakness and symptoms because CASE Aged sixty sanatorium sanatorium emaciated emaciated emaciated operating talcum years examination showed emaciated Phevital emaciated powder mixing mixing exhaust ventilation ventilation dust with individual provided capacity control The who looked chronically vital as 3,0007 1,800 normal estimated middle found dust Industrial Industrial The used middle contain Division Division cent thirds lungs dullness over middle middle anteriorly lungs showed second anteriorly and of posterioly Hygiene dust concentrations concentrations concentrations work posteriorly Five bacillus free silica concentrations concentrations at this work negative sputum posteriorly above specimens and tubercle tubercle bacillus ranged 13.9 to particles per million negative normal extensive For footfoot The dust quitting the The bi- years before temperature normal Roentgen examination extensive bi- For or four showed tubercu- the claimant lateral complained cough wit thhe infection probably tubercu- expectoration expectoration expectoration Examination Examination lungs lous this diagnosis twenty bases estimated capacity moist r^lesthe 4,000 vital CASE years IV Aged thirty seven one twenty-one claimant had worked twemnitneys mines as mines aS examination Roentgen examination the lungs showed an and foreman in years two years increase examination lower and mucker driller work had noticed cough markings gone quitting fields with areas increased increased density and before was areas in both both shortness had noticed cough breath and was These symptoms symptoms caused st. Fie was caused cu lipiodol lipiodol calcific deposits enter midlung of deposits to fatiguetdreatment treatment caused lung diagnosis was made in ab- hospital emphy- 17 bronchitis bronchitis revealed Physicalenter hospital normalties examination examination revealed hypertrophy no lung showed cardiac hypertrophy, chronic bation bronchitis made in hospital of hypertension and A diagnosis Was with acute exacer- bronchitis sema and chronic evidence nephrosis hypertrophy and nephrosis of nephrosis- hypertension bation. Vou. 49+ .y and i probat previo previo Roen fine no 49 fifi Roen Roen ca The central central The Cas probat previo mines. cough '6toms} and st Ph) indivi | were limite hess rales: was f Ro. micre with at th Th com) Di miss REP e AY 1943 two laster inufacar and on eather Division rain no e com- * weak- ospital ence of ingers less on breath .howed .odular ibrosis fatally ital nt had s with breath k two Luse of to iciated e vital 3,000 middle y and ns of acillus ve bibercu- one ines as years cough le was d him ng ab rophy : The Dust Hazard in Tremolite Talc Mining 15 examinationexamination of the chest showed Aulationthrough both lung fields below 1th posterior - Aulation rib more marked in the 1lth ung field an increase in hilum shadows hypertrophy cardiac The silicosis with diagnosis was early silicosis with clinical disease and obable infection hypertensive eerree nephrosis case terminated fatally The The claimant had ASE v Aged fifty ked in talc mines for seventeen years with a of ten years in zinc and iron Pe Crious exposure mes Illness began six years before death with cough and dyspnea Following the initial symp he developed pain in chest and hemoptysis and sought hospital treatment and Physical examination showed an emaciated individual appearing chronically ill The fingers ere slightly clubbed The chest expansion was mited Examination of the lungs showed dull- on the right below the seventh spine with ales and diminished breath sounds The sputum Roentgen oF was positive miliary examination showed a fine miliary type of increased density on the left a mass of increased density in the right middle lung field with evidence of excavation and heavy fibrosis Pat the right base complicated The clinical diagnosis was probable silicosis complicated by tuberculosis Death occurred twenty months after ad- mission to the hospital REPORT REPORT OF A STUDY OF TALC MINERS MILLERS IN ST LAWRENCE AND dustrial Hygiene Patterson high speed screens were used and exposures were made at a 60 inch distance and with an exposure time of tenth of a second Type of Tale Involved The type of talc produced in St. Lawrence County is of the fibrous variety known as asbestine It is noted for its clear whiteness and is used chiefly as an ingredient in the manufacture of paint and tile With it is found tremolite calcium magnesium silicate CaMgsSiO3 similar appearing mineral occurring in a fibrous or asbestiform state which in the course of time changes over to talc Gardner reports that anthophyllite another fibrous silicate is also present in the talc deposits of the St. Lawrence County region Analysis of representative samples of talc from two of the mines in the region sub- mitted by one of the mining companies shows the following composition Analysis Total silica Calcium oxide Aluminum oxide Iron oxide Manganese oxide Carbon dioxide Magnesium oxide Calcium carbonate Sulfur trioxide Ignition loss Sample A 6824 6824 2.72 _- Sample B 57-50 5.24 .27 .17 .16 .38 3.65 5.13 COUNTY NEW YORK 99.35 99.05 Scope of Study In the course of this in- The free silica con- vestigation studies of operations and dust * made by engineers Free silica content tent of commercial talc as found in indus- concentrations were of the Division of Industrial Hygiene in trial use is very low Schulz and Williams three talc mines and five talc mills Two report that of 51 samples analyzed quartz and men from seven was not found in 25 traces of quartz only hundred twenty plants received an initial roentgen examina- were present in 25 while one sample showed concentration of 3 per cent The tion In the case of 28 of these individuals a quartz free silica content of the talc in the mills and who showed positive lung findings a follow- mines included in this study was likewise examination was made at the end of ten up months which included a second roentgeno- found to be low Six samples from two talc by chemists of gram a medical history and physical ex- mines taken and analyzed the Division of Industrial Hygiene showed amination of the chest and a detailed oc- I per cent or less of free silica Two of these cupational history me The examinations were made samples were taken from long standing roentgen with a 200 milliampere machine mounted accumulations of waste rock two were ; on truck belonging to the Division of In- * Includes both free and combined silica and Leonard Greenburg January, 1943 William William Adelaide Ross Smith 16 Tremolite bundle-like Tremolite talc, Note Bic. 5. of fibers. (Magnifica- Tremolite like 1. talc Note Note bundle Fic. te stu fac ranging from {2 to 20 amounts quartz ranging waste 12 20 mines roc run quartz quartz ranging the qu: accumulations accumulations and and were from collec- cent samples samples from two mines tions destined destined the mills Six this area mineral explain find- difficult find- samples ground talc from mills marked difference Gardner's 1 gra samples and from several also analyzed ings and those difference between Gardner's ourselves ourselves were found be each the supposition Dreessen Co silica content was reported than than except upon the supposition that Gardner's Gardner's lon Dreessen also reported included per Dreessen or samples supposition quartz bear- deposit composition reported overlying overlying lel not ing stratum are free the the tale in in the composition such high percentages deposit the sh: That Gardner this region percentages percentages not by pei representative in Gardner Gardner other found representative Gardner,fion the 2,500 X. ) Magnification Magnification Magnification needle-like fibers. (Magnification 2,500%.) burg JANUARY 1943 talc Note bundle of fibers Magnifica- inch 10 microns The Dust Hazard in Tremolite Talc Mining ing from 12 to 20 les from two mines ult to explain the en Gardner's find- en and ourselves ion that Gardner's of the quartz the talc deposit ercentages are not , is shown by the fact that material from the mills where all rock is mixed and crushed showed low quartz percentages both in Gardner's studies and our own Microscopic appearance Photomicrographs of talc dust from St. Lawrence County show that it tends to occur in oblong or squarish particles made up of parallel fibers Fig ) which splinter off into sharp spicules Fig 2 Its microscopic appearance differs from that of asbestos Fig 3 in that asbestos fibers tend to be curved and tendril in form whereas those of talc appear straighter and needle in structure Tremolite talc fibers are also much shorter than those of asbestos In this study their maximum length was approximately 15 microns Asbestos fibers on the other hand may attain a macroscopic length In interesting contrast to both tre- molite talc and asbestos are the flake particles of mica dust Fig 4 another FIG 4- Mica Typical mica particies showing the very thin platelike structure Magnification 2,500 X. and {Leonard Greenburg Jancazy, 194d Adelaide Ross Smith William William 18 Greenburg JANUAry JANUAry Greenburg silicate and granular granular Smith and Leaonanrd d pushed it is JANUAry 1943 a magnesium magnesium the granular muck muck cars pushed along the haulage- ticles ticles granite granite dust the Fig combina- essentially essentially quartz ways the shaft where dumped dumped CO skip hoisted shaft where dumped to the surface tion Description Description of Industry into railroad cars Each trucks fifteen mills underground underground employs Talc Talc ore obtained seventeen men underground underground underground of to operations Talc Mining operatmiionnsing Inclined shafts obtained down Dust exposure exposure operations operations re- The The problem problem the best mining mining by underground various depths used used headings headings a ie silicate found form Granite. Shows lack of form form silica Fic. 5. Granite Shows Shows lack Von. 49, No. t Tale Mill No. a Talc Talc five m Talc Mill Milling a five lead The c DUST CC Opera- Mu tion Drilling 2 entering wtiitohnisn actual Thesreespirators sampling All Division Division In- of In- the attention attention In- Very homogeneous seams so that contact contact Hygiene Hygiene present present time Very Very three with hard rock limited that incurred incurred dust control was found the been been seam seam entered entered attempts had there no exposure exposure Once but talc studied Some dust during drift drift enter anything anything anything until becomes necessary necessary another drilling by means the small home made units means small these of these seam Since Since may worked for years hard but relatively few the amount drilling hard rock very were compared with the amount drilling drilling The drillers use during drilling operations operations small with the amount talc talc drilling Twenty Twenty two respirators were taken taken The headings mined by drift impinger samples various opera- opera- blasting blasting resorted resorted mucking and situations situations variouwsere counted counted hours Raising stoping stoping from pockets ten time of sampling sampling means means low power tech- tech- tech- obtain ore precaution nique taken since every precaution nique and gave results results shown shownTable in Table1. cannot device avoid avoid ore which dust counts where no exhaust device was milled wasted Drilling crews wasted was gave average dust concentrations concentrations concentrations concentrations two men drillers doing their 1,350 blasting blasting The used drillers mucked as as 1,290 general The then 1,290 follows for drilling stoping stoping for mucking 35 and cguebniecragenleral general required blasting is loaded into the mills mills air 17 particles particles cubic million . foot. or two is then into as blasting. The ore into million cubic foot air, 17 o rewqnuired by the mills. It is loaded JANUARY 1943 ie haulagenped into a id dumped hipment to fifteen to operations of control which is re- lsack of form icate and silica ation 2,500 X. ivision of Init time Very in the three ts had been during drift home few of these ig operations were taken arious operawere counted : of sampling ght field tech- wn Table xhaust device oncentrations > for stoping n the general cubic foot The Dust Hazard in Tremolite Talc Mining 19 No. 1 4Milling villing operationsoperations The milling processes tive mills were found to be essentially The ore is shipped to the mills in railor trucks and is dumped into ntes crusher leading to a jaw crusher From the crusher the talc in most mills passes TABLE II DUST CONCENTRATIONS IN TALC MILLS Operation Mill Dust Counts million particles per cubic foot Average Dust Concentration million particles per cubic foot TABLE I IN 1ALC MINES DUST CONCENTRATIONS Crushing crusher 1 876 2 876 76.5 46 Dust Count Opera- million Mine tion particles per cubic foot Remarks Crushing or 1 22 roller crushing 2 22 50 Pebble milling I 248 46 248 61 Upstream of drill Rate 2 per minute Bagging paper 3 Downstream of drill 1 3 upstream Using ex- + haust 110 Same as above Breathing Bagging burlap I level of helper . ... 600 Exhaust off 2700 Exhaust off Breathing level of helper downstream General air cylinder 1 5000 Exhaust of dust collector room 3 1500 Same as above 3 minutes 4 after drilling stopped 5 150 General air stream Separator room 4 Upstream air movement 50 per minute 265 Same as above Air turbu- Manual handling 1 lent 718 718 718 A 7.3.5 ** 875 * Mon Mon Mon 58 67.5 163 93 72 62 go Dead end drift Just off main airway 16 Main airway 100 Breathing level driller top of open stope 760 Dead end stope No air movement Top of dead end raise 40 Bottom of stope drilling at top Same as above Top of pile mucking only operation Downstream of mucker 24 Same as above through disc or roll crushers or both before entering rotary or trommel screens After passing the screens the talc is stored in garners before the final milling operation which takes place in pebble mills The final separation of the finely ground talc is accomplished with air separators from which the material passes to garners which feed bagging machines The bagging machines utilize open top bags or sacks which fit loosely onto the discharge spout of the machines Hand scoops are used to add or remove talc from the bags to obtain accurate weight The greater percentage of material is bagged in * Greenburg January, 1943 Siegal Ross Smith and Leonard William William 20 Leonard some shipped in Smith bags while paper fibro- 50 lb. larger shipped shipped bags operators Roentgen larger burlap larger stack operators operators of recording bagging machines the bags wheel 1s recording pulmonary Fibrosis pulmonary with slight or on Incidence Incidence fibro- fibro- hhaandndhand trucks and recording pulmonary among workers or e sis moderate degrees degrees fibrosis slight even fibrosis fibrosis dis- TABLE TABLE regarded regarded andonly those LENGTH EXPOSURE WORKERS WORKERS LENGTH FIBROSIS IN TALC which marked condition condition condition present . roentgen Upon survey survey 221 men es Upon the initial roentgen roentgen of survey 1940 1940 . Expo- fibrosis found in 32 i men Workers giving rate of 14.5 Fibrosis Examined Examined Examined Fibrosis sure The The exagmiinedving these cases according according m1. Exposed Group Cases xposed 5amined ber to length distribution distribution according in cent per cent per It length of exposure exposure shown shown occurred with seen that cases occurred * 11 exposure 11 ~ workers than ten years exposure 5 82 ~ The 32 cases fibrosis were found found talc 25.0 170 8 among the men fibrosis worked tale 15-19 a worked 3 63 39 for ten years longer who incidence incidence of 33 94 20 for group group giving giving incidence of men 25-29 2 10 33.3 rate years more more 30 3 15.6 29.9 per cent in 15.6 833 employment 3 9 40-49 6 3 who had worked cent Of the men 3 years 50-59 L 1900 showed showed thirty per more is a 21 \ talc fact per cent talc 14.5 Totals 32 make make the distribution talc of 100 0 14.5 32 the of tale producing ast Totals ee fibrosis fibrosis according distribution distribution talc into cases carpet factory storage . workers in group group ofcarpet factory the warehouse workers previously Dust exposure exposure ithne milling operations operations control exposure shown shown Table iv tv. Fibrosis only 2.5 cent cent confined Dust bagging various mills chiefly the machines machines and pebble carpet present present 4.9 per cent cent cent all carpet workers and several mills Some control control material several mills the the crushers material material transfer transfer IV IV points Dust samples were through- By ACE taken out the mills using wewreere technique already ACE FIBROSIS IN TALE CARPET WORMERS described The samples taken the level the workmen locations the Workers Workers Workers Carpet eee breathing breathing stationed locations where are usually concentrations found fibrosis Sbrosis fibrosis Num- fibrosis shows the concentrations concentrations Num- ber various e4xam- exam Num- Per Per throughout throughout Manual handling points . cent ined ber Num- ber cent centrations handling handling the producefousnd con- ined bers cent cent a excess operations those than 20 other operations fortunately fortunately fortunately there 20-29 20 _ 6 _ manual during normal pro- _ 57 4 - = cedure handling hanopderlaitinong pro- pro- 30-39 72 71 45 7 1 4 1.6 1.7 1 1.6 The dustiesopteration other man- 40-49 17 17.0 57 49 8.1 voo8s7 handling handling 13 46.1 7 8 4 49 66.6 9 33 _ _ average for three 70-79 3 63 33 _ was found concentration where 3 313 66.6 _ 3 cubic foot to 163 163 million particlfeosr Totals 221 2 14.5 266 6 2.5 concentration particles the averagfeoudnudstto be 163 million Totals 221 gz 14.5 a mills was _ per cubic foot. Vou. 49, No. of those fifty years ' . No. : in workers in this age gi those years o was present present o workers this age months months after after o study second visit tak for follow upe F histories time time poss were were tak previ histories made F silicec who was poss poss sh types had previ men cases silice inc of defined st ex other dusty inc dust ex inc talc ex we Signs and sympto T fibrosis wc wc Ir miners miners " to miners was re 0 Fre. 6. Case 200-28. 1 200-28.2 200-28.2 of fifteen. W W twenty-five five of breath breath breath Chest breath sounds d d igen examsnatir examinati on 2 diffuse are thicken JANUARY 194 nary fibro th slight or s were dis ncluded in ey in 1940 < 221 men : per cent according 1 Table III ccurred in exposure all found ked in tale 1 incidence or more of the 8 men e years in een ntt t talc is a ribution of ge in talc .5 per cent 9 per cent RS BY AGE st Workers With fibrosis present ifty of age and older while years cent of talc in 51.5 per examinations this age group months after the original roentgen second visit was made to the same Re selected forAt this time occupational and meditories tories were taken and chest examina- mademade From the occupational ries were to eliminate those ries it was possible who had previously been exposed to of siliceous dust In this way a types showing marked fibrosis of 18 cases defined in men who had not worked in other dusty industry and whose only EEfficantfficant dust exposure therefore had talc and symptoms Fifteen of the men proportion nowing nowing were fibrosis worked in the talc mills The miners entire of mill in miners how- workers to workers miners showing Efibrosis was in the entire group 2.3 to , approximately Efibrosis Efibrosis was relatively more prevalent ; , Fig 7. Case 198-3 Aged four Began work at age of fifteen Farmer sixteen years telephone linesman seven years talc mining sixteen years Complains of productive cough and dyspnea Physical examination Chest expansion inch Nails curved Roentgen examination Shows enlargement of the hilar nodes and exaggerated linear markings at the right base There is also a fine generalized diffuse fibrosis having a granular appearance among millers than miners With one ex- ception the men with fibrosis were all forty years of age or older and had been exposed to talc dust as noted above for at least ten fa 6. Case 200-28 Aged forty Began working at age of fifteen Woolen mill six years talc mill worker twenty years Complains of cough hortness of breath pain in chest fatigue Physical emination Chest expansion 11 inch respiration breath , sounds diminished Clubbing of fingers Roentgen examination Shows a very fine granular Vibrosis on a diffusely hazy background The hilar nodes are thickened years Thirteen of the 18 had one or more symp- toms referable to the lungs Ten complained of dyspnea 7 of chronic cough and 3 of pain in the chest In addition 5 com- plained of excessive fatigue On physical examination all 18 showed limited chest expansion Thirteen showed abnormal lung signs and 13 showed curving of the nails or clubbed fingers In one case cardiac hypertrophy was observed and in one auricular fibrillation The general appearance of the group struck the examiners as being distinctly different from the appearance of the usual of first and second stage silicotics group who are still able to work The latter usually present a robust appearance A substantial number of individuals in such a group are William Adelaide insshtaagngca iensen ss d wheirlear William dence Jee" 1943 Ross Smith and Leonard Greenburg show a Greenburg Greenburg JANUARY ( Smith Smith Leonard Leonard Leonard Greenburg Greenburg JANUARYJANUARY 1943 in or moderate and 1943 Figures show show a slight increase increase nodes slight moderate moderate Evi- oF dence pleuritis pleuritis and obliterative obliterative emphy- 15 presentpresent in cases ' cent or 221 shagginess the cardiac cardiac outline is were 29 (13-5 outline Tuberculosis Tuberculosis In group 221 (2-7 the talc workers there were cent type 2.7 of primary 6 cases healed healed tuberculosriesinfectiontuberreciunlfoescitsion type type the F tuberculosis tuberculosis healedper cent cases clini- groups teponi- Complains Fic. at age fourteen Talc expansion at forty one years examination examination Roentgen examination fifty Began working which considered the appearances clini- re- tuberculosis alone show in significant significant tuberculosis primary show healed incidence incidence primary and re- in lesions not e infew ctionaty ypebeingbeing similar remarkable remarkai ble n other industrial incidence fingers diaphragm right of elevation costophrenic costophrenic sulcus with diaphragm a fine granular granular fibrosis lungs fine, granulz likely to @ who showed the the fibrosis . None None workers overweight overweight showed contrary None them on bu t present undernourished undernourished they they tended appearance appearance appearance an the impressionimpresion drawn It examiners was of examiners also, dyspnea unusually unusually pronouncedpronounced 1n extent relation relation roentgenograms fibrosis s fiberoseisnseen i10 the roentgeRoenntgenoograpghic raRoemntgsenographic characteristics characteristics characteristics Roentgenographic fibrosis these roentgenograms is (YPE showing 1s diffuse very many appearance showing cases appearance appearance haziness 1 to many working ground ground 9. de- eight working n working car- term scribing asbestosis used sixteen sixteen Farmer sixty years years; cases scribing certain can in age talc milltwenty three map repair man repair ; This dyspnea illustrated well be applied penter numbernumber illustrated number examination expansion months months Complains laborer laborer and years Complains Physical Physical Physical respira- respira- respira- cases Figures and distinctly granular Chest Roentgen inches examination. distinctly appearance addition nodula- appearance and and some nodula- tion bases nodular Roentgen examination examination throughout FI appearance and Fig might might con-Shows diffuse finely fibrosis throughout is emphysema both with silicosis and which films certain films soft There the pleura apparent thickeningthickening thickening at density conglomerationsconglomerations atlhessoe ocecrctauirn Fig and)bbe e rriegghiotn shadows with several horizontal There area area increased from also the third interspace The fibrosis in cases tends more marked side extending extending second the and somewhat on the side side the seen possible at both apices reinfection tuberculosis . suggesting lung The lung fields and bases the right possible on reinfection tuberculosis rein fection tuberculosis: more marked on as seen possible somewhat fields and bases and in the mid-lung Vor. 49, NE losis (2.2 founidn No fou 1.2 per 2.2 in t fou per clinicall siz minima int showed six men six plicatii Tale in this becau: was per ce roent{ depos pleur. are $ the r in working years car- repair man a Physical s respiraamination -hroughout e left base cura at the ows in this ed density interspace suggesting cent is slightly higher than is in in pemorst industrial groups the average condition about ound for this being with individuals er cent Among the 5 be- icaly significant tuberculosis 3 ically of thirty and fifty showed en the ages one forty years of age imal imal lesions advanced lesions and Wed moderately sixty years of age showed what interpreted to be far advanced atypical berculosis Among the 18 cases of fibrosis berculosis men exposed only to talc clinically sig- Rificant tuberculosis appeared to be a com- cent plicating feature in 3 cases 16.6 per finding Talc plaques A most interesting workers Ba this group of talc interesting these investigators it was new because because to was the presence in 14 instances 6.3 roentgenographed per cent of the 221 talc workers originally of what appeared to be 3 deposits of opaque material on various pleural surfaces These deposits or plaques seen on the visceral pleura including the region of the diaphragm and occasion- FIG 11. Case 201-10 Aged forty Began work- ing at age of sixteen Farmer seven years talc mill laborer and foreman twenty years Complains of productive cough dyspnea and fatigue Physical examination Chest flat expansion limited dullness at apices otherwise hyperresonant R^lesthroughout most marked at bases Respiration 22 pulse 116. Heart negative Clubbing of fingers Roentgen examination Shows a fine soft mottling over both lung fields more pronounced at the bases In addition in the third left interspace near the periphery is a round homogeneous area of increased density about 2 cm in diameter EN FIG 10. Case 197-8 Aged forty Began working at age of fourteen Talc mill laborer thirty years Complains of dyspnea pain in chest fatigue ' Physical examination Chest expansion 1 inches y Nails curved Roentgen examination Shows diffuse finely nodular fibrosis with soft shadows suggesting bilateral clinically significant apical tuberculosis ally the pericardium Fig 8 and 13 to 17 Lateral and oblique views indicate that their location is definitely at the periphery of the lung not involving the parenchyma Fig 17 In size the plaques vary from a single appearing deposit of a few centi- meters in length in the region of the diaphragm Fig 8 and 12 to massive deposits bizarre in shape extending over a large part of the lung fields Fig 14 15 16 and 17 They are characterized not only by irregu- larity of shape but by marked irregularities in degree of density also and by the sharp- ness of their borders In this series of films the development of these plaques can be traced from small light scarcely noticeable deposits to the extensive opacities de- scribed William Siegal Adelaide Ross Smith and Leonard Greenburg JANUARY 1943 24 An analysis of the group of 14 talc r workers who showed these deposits revealed the following facts Their ages ranged from thirty to seventy years and their exposure in the talc industry from four ? to fifty years Ten were mill workers 4 * were miners Only one individual gave a history of having had pleurisy None had had empyema In 5 instances no lung path- : ology other than the plaques was noted A # marked degree of fibrosis coexisted in i cases Evidence of clinically significant tuberculosis was seen in one case and of 4 4 nbipaoney. primary healed tuberculosis in another case No symptoms or physical signs attributable to these deposits could be identified FIG 12. Case 200-20 Aged three Began work- ing at age sixteen Fireman three years farmer eight years talc mill laborer and repairman thirty years Complains of dyspnea and fatigue Physical examination Lungs hyperreso- nant Heart slightly enlarged to left rate irregular Clubbing of fingers Roentgen : Shows deposits of opaque material on the left diaphragmatic dome marked emphysema at the left base Both lungs show shiffuse granular fibrosis with irregular patchy shadows at right base and left mid- lung field It should be noted that roentgen appear- ances similar to the plaques herein described were apparently seen in Case I where mention is made of areas of increased density resembling lipiodol or calcific depositsin lung fields Similar appearances have also been noted in another group of workers who were exposed to talc dust in the making of material for electrical insula- tion So far as can be ascertained these de- posits bear no relation to any history of previous infection since they occur bath with and without such a history Nor are they necessarily associated with other pulmonary pathology The underlying lung tissue may or may not show fibrosis There is no associated enlargement of the hilar nodes in cases showing plaques without fibrosis FIG 13. Case 201-5 Aged fifty Began working at age of fifteen Farmer seventeen years repairman in tale mill eighteen years Complains of cough Physical examination Lungs show diminished breath sounds throughout especially on right Heart systolic murmur at apex Pulse 120. Clubbing of fingers Roentgen examination Shows a soft diffuse very finely nodular fibrosis throughout both lungs In addition there are irregular sharply defined deposits of opaque material in both middle and lower lung fields Lateral and oblique views show that these plaques are located near the periphery There are similar deposits on both diaphragms and in the region of the right spinal gutter VOL 49 No # since in the gro signs only occu whom there was parently the pl process responsi symptomless Fibrosis The study was cha scribed by a : granular or nod be more marked bases Dreessen tion somewhat of tremolite tal graphical area reported was m FIG 14- Case 196- at age of fifteen railroad four ye years No compl expansion 34 inc Curved Roentge pears to be an ex deposit of opaq~- . Stereoscopic vies periphery prob Bx that the lung be : fibrosis The righ fibrosis with interspaces sugg