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FILE NAME Talc TALC DATE 1949 Nov DOC TALC498 DOCUMENT DESCRIPTION Journal Article - Study of Workers Exposed to Talc & Other Dusting Compounds in the Rubber Industry BC Notes 1949 Published report by Hogue and Mallette A Study of Workers Exposed to Talc and Other Dusting Compounds in the Rubber Industry referencing 1942 and 1943 reports on NY talc miners by Porro and Siegal et al JIHT 31 359-364 1949 vol 31 no 6 at poison with tic renal and adily through tration should phere and no permitted thylene chlor- ommended for red continuous a chamber is nain on dur- nclude medical bols ER C. .: Note chlorhydrin by 945 Suggestions for ydrin treatment ntly harvested opson Institute DENNY F. E rates and time nternal factors 41 611936 three chemicals otato tubers to ms of the Boyce Sept 1945 A STUDY OF WORKERS EXPOSED TO TALC AND OTHER DUSTING COMPOUNDS IN THE RUBBER INDUSTRY WARREN L. HOGUE JR AND FREDERICK S. MALLETTE Firestone Tire and Rubber Company Akron Ohio ALC and similar minerals are widely used in industry In the Mineral Yearbook Johns- ton and Barsigian 1 report that in 1946 over 450,000 short tons of domestically produced talc pyrophyllite and ground soapstone were consumed of which 77 per cent was utilized in five industries rubber roofing ceramics and insecticides The paint industry alone used 23 per cent of the total 1,440 million particles per cubic foot in pneumatic drilling operations and as low as 4 million outside the mill proper He reported that in only three cases % were the ray findings within the limits of normal 38 67 showed evidence of an early or stage pneumoconiosis Only one that of an individual who had been in the tremolite mills for over 40 years fibrosis advanced beyond the first stage Dreesen con- CHEMICAL COMPOSITION cluded that the not disabling resulting pneumoconiosis was One should note that the mentioned re- port groups talc with materials of like commercial applications rather than with those of mineralogical or chemical similarity Actually talc is a hy-. drous magnesium silicate with the formula Mga- In 1935 Dreesen and Dalla Valle 5 reported dust concentrations varying from 32 to 1,672 million particles per cubic foot in two Georgia mills Among 66 workers examined they found 8 having advanced pneumoconiosis with disabil- SO Other minerals which have similar ity and 14 having roentgenographically demon- uses are pyrophyllite a hydrous calcium mag- nesium silicate Ca MgSsierpentine a strated slight pneumoconiosis without disability The dust was found by analysis to consist chiefly hydrous magnesium silicate MgaS andO7of soapstone but it also contained 10 per cent dolomite a calcium magnesium carbonate CaMg- tremolite The authors stated that the dust of the CO2 Tremolite frequently found in nature with talc has a fibrous variety which is used to some extent as asbestos 2 Soapstone is the granular to cryptocrystalline form of talc Apparently the physical characteristics of all these materials are so much alike that they may be used in almost identical applications and therefore are designated commercially as talc Schulz and Williams 3 pointed out that talc as used industrially generally refers to a substance which meets certain physical requirements rather than one which has a definite In an examination of 71 found extreme variation chemical composition analyzed samples they in composition PHYSIOLOGICAL EFFECTS Georgia mills appeared to be more injurious than that reported by Dreesen 4 However the study made in Georgia showed much higher concen- trations of the dust Furthermore quite a few of the miners had worked in hard rock although only 6 out of 13 showed pneumoconiosis stage I. Eason Trice and Carpenter 6 reported pul- monary fibrosis among miners and millers of pyrophyllite characterized roentgenographically by massive tumor shadows bilaterally situated in the subapical region or by granular densities distributed throughout the lungs Of 101 workers 35 per cent of those with two or more years of exposure showed evidence of pathologic changes in the lungs The pyrophyllite dust contained from 25 to 35 per cent quartz In general most silicates of this kind were considered harmless until 1933 when Dreesen 4 Porro Patton and Hobbs 7 found 15 cases of pneumoconiosis in two tremolite mines and studied conditions in tremolite mines and mills He found dust exposures averaging as high as mills in New York State According to them the composition and concentrations of the dust were * Presented at the Annual Meeting of the American Industrial Hygiene Association Detroit Michigan April 5-8 1949 the same as those reported by Dreesen 4 who had previously surveyed one of the plants Non- disabling pulmonary fibrosis was found in almost 359 359 359 Material may be protected by copyright law Title 17 U.S. Code 360 ' JOURNAL OF INDUSTRIAL HYGIENE AND TOXICOLOGY vol 31 no 6 all of the workers examined Of the 15 patients 7 were known to have worked in other types of mining operations Dyspnea was an almost universal complaint and several patients had cyanosis and club fingers In all of those tested with a spirometer vital capacity was very low 35-52 per cent In the 5 postmortem examinations asbestosis bodies were a fairly frequent finding in lesions of the lungs This may not be puzzling when it is recalled that tremolite is characteris- talc in the past to pyrophyllite were those of refiner operators strainer operators mill men truckers slab checkers and shipping laborers The results of the surveys have been averaged for the period 1943 to 1948 and are presented together with the number of years of total exposure of the various occupations in tables 1 and 2 It must be emphasized that before the installation of control ventilation the dust concentrations were probably much higher tically fibrous Further studies in tremolite mines and mills of northern New York by Siegal Smith and Greenburg 8 disclosed 32 cases of advanced fibrosis TABLE 1 AVERAGE DUST CONCENTRATION AND PERIOD OF EXPOSURE FOR WORKERS IN TALC in a group of 221. Dust counts in the mines varied from 6 to 5,000 million particles per cubic foot WORKERS EXPOSED MILLIONS EXPOSURE EXPOSURE CLES FI in milling The talc was of the asbestine variety and was mingled with tremolite and anthophyllite 6 tube machine operators 20-34 20 The fibrosis tended to be disabling and was fre- 3 tube bookers eee: 32-36 35 quently accompanied by dyspnea cough and 10 tube cure men 6... 10-34 eee | 15 fatigue 1 liner reroller see 14 50 Prompted by these reports and by proposals 11 AVERAGE for the inclusion of a limit for talc among dust TABLE 2 12 hazards in certain state codes 9 10 11 we made where workers had DUST CONCENTRATION AND PERIOD OF a study in two rubber plants WORKERS IN WETTING PYRO- 25 been exposed to talc and other dusting compounds EXPOSURE FOR PHYLLITE AND TALC 19 for periods as long as 36 years Talc dusting ex- 16 MILLIONS periments were made on laboratory animals the 18 results of which will be reported in a separate PT 20 18 18 communication DUSTING RUBBER 13 refiner operators 13-25 50 3 strainer operators 15-25 75 22-42223 As rubber is naturally tacky it must be coated with a lubricant to keep it from sticking together Many materials are used both in the wet and the dry state for this purpose Among them are talc 1 man 22ers 3232 1 trucker 6. - ee eee cece 3232 1 slab checker ee 3232 1 shipping laborer 3232 50 30 50 150 pyrophyllite mica clay walnut shell dust corn starch whiting et cetera Operations employing DUST COMPOSITION these materials in the dry state tend to be very dusty In recent years control ventilation has reduced the concentrations of the dusts but there are still operations especially of an intermittent or temporary nature which it is difficult or im- practical to control In these operations dust respirators must be relied upon for protection For the past six years periodic dust surveys The dusting compound used in the tube opera- tions and in rerolling liners is a pure talc from a deposit near Johnson Vermont and contains no free silica tremolite chrysolite chrysotile or ac- tinolite It has the following composition Tale Analysis Silicon dioxide . 34.86 have been made of several processes in the manufacture of inner tubes and in the reclaiming of Ferrous oxide ..- essere eters Aluminum oxide 6.30 1.22 rubber The occupations in which talc was the only dust to which workers were exposed were those of tuber operators tube bookers tube cure men and liner rerolling Those jobs in which the major exposure was to whiting and the minor to Manganese oxide .. e+: Sodium oxide . 0... ec eee ee eee Potassium oxide sense .....-60ee- Combined 66. e wates r eer Carbon dioxide cere 0.09 0.53 Trace 6.17 15.10 Material may be protected by copyright law Title 17 U.S. Code vol 31 no 6 ere those of , mill men ng laborers en averaged e presented I total expobles 1 and 2 installation trations were = PERIOD OF TALC MILLIONS | ES OP OF PARTI- / SURE CLES FT -34 8338 -36 8338 -34 8338 50 D PERIOD OF TING PYRO- MILLIONS RS OF } CLES CU 7501E OF FANTIFT -25 5-25 24 20 23 24 82285 82285 82285 82285 50 150 he tube operare talc from a ad contains no ysotile or ac- osition 34.86 6.30 1.22 0.09 0.53 Trace . 6.17 .. 15.10 Nov. 1949 TALC DUST EXPOSURES 361 Whiting calcium carbonate is the principal compound for dusting reclaimed rubber Until about six years ago pyrophyllite containing 65 per cent free silica was used for certain stocks but since that time tale has been used for these special applications but the use of both compounds amounted to only about 10 per cent of production CLINICAL INVESTIGATION The two groups of workers included in this study were specially selected for type and length of exposure Only those with the longest and heaviest exposures were included Complete physical posed of 20 men who had been exposed to talc alone for periods ranging from 10 to 36 years All of the men were working at the time of the study and were in apparent good health None of them presented any symptoms referable to the lungs such as dyspnea cough or shortness of breath None had clubbing of the fingers or cyanosis Only one member of this group had subnormal 71 per cent vital capacity This finding can perhaps be explained by the presence of an enlarged heart as determined by the Hodges formula In this group the roentgenographic findings were either completely normal or showed only TABLE 3 PHYSICAL EXAMINATION VITAL CAPACITY DETERMINATIONS AND CHEST ROENTGENOGRAMS ON WORKERS EXPOSED TO TALC 117R 8839883 25 118R 119R 126K 8839883 5 30 8839883 5 24 8839883 31 908K 8839883 25 251R 50 30 196R 8839883 20 167R =. 62 36 187R =; 49 30 205R 49 32 186R 49 25 246R | 51 10 209R | 47 32 207R | 52 31 17R 58 27 287R =: 50 24 206R 57 34 290R 43 14 292R 51 19 286R 39 18 20 144/92 86 Negative 35 152/80 | 105 20 112/68 | 119 +10 Coal miner years 35 132/78 | 122 20 142/82 : 71 +17 15 142/80 | 112 - 20 160/90 | 94 Normal 35 120/80 : 95 " , 44 " << Coal miner years 15 140/70 94 15 130/80 | 118 44 15 124/90 | 107 15 110/70 | 121| 15 95/65 | 86 15 112/80 | 102 | Normal 15 140/95 | 118 20 138/78 | 116 | Normal 20 194/94 85 50 104/71 105 15 110/65 | 93 15 120/55 | 114 { ( " " " " << Coal miner years examinations including blood counts urinalysis blood pressure readings and vital capacity determinations were made For the latter tests the McKesson apparatus was employed and readings below 85 per cent were considered indicative of disease of the heart or the lungs Roentgenograms of the lungs were made on 14 X 17 films and interpreted by a qualified radiologist with considerable experience in the diagnosis of pneumoconiosis TUBE WORKERS Physical and Roentgenographic Examinations The first group presented in table 3 was com- the chronic changes found in industrial urban dwellers See figure 1. RECLAIMING RUBBER WORKERS Physical and Roentgenographic Examinations The second group presented in table 4 was composed of 20 men with a major exposure to whiting and minor exposures to pyrophyllite and talc The exposure periods of this group ranged from 10 to 25 years All of these men were also working at the time of the study and none complained of or presented symptoms referable to the lungs such as dyspnea cough or shortness of breath No clubbing of the fingers nor cyanosis was noted Material may be protected by copyright law Title 17 U.S. Code a 2 FIG 1. This man is 62 years 35 million particles exposure of 35 million particles per accentuation of the lower lobes and cubic cubic has worked His foot His in vital vital rubber the capacity capacity industry for 36 years with an 95 was 95 per cent These These lungs lungs show show average talc only truncal truncal TABLE 4 PHYSICAL EXAMINATION VITAL CAPACITY DETERMINATIONS AND CHEST ROENTGENOGRAMS ON WORKERS EXPOSED TO WHITING Pyrophyllite AND TALC WORKER | 229R 244R 228R 953R 195R | 226R | 248R 170R 165R ! 18L 185R 247R 234R 231 232K 164R | 184R 235R 217R 972R | YEARS OF EXPOSURE 3238 3238 3238 24 3222 3222 3222 13 20 20 18 20 23 23 24 20 23 | MILLIONS OF PART- PRESSURE GENOGRAMS | FT VITAL PRESSURE | CAPACITY | HEART REMARKS . ; 160/100 _|_. % +17 _. Negative |e Previously coal miner | 158/86 104/56 60 25 85 | Normal 132/90 68 | : Pneumonocon- | Coal miner years iosis III 50 124/90 116 | Negative | 7550 | 50 140/70 | 99 | - 130/90 90 Normal 120/70 | 123 $ $ << 50 | 50 130/80 | 73 | << 50 112/62 | 110 | 6 50 ' 180/98 101 1-10 ' " 160/85 | 119 Normal | 120/70 110 1 132/80 | % | < 130/70 74 +21 1 142/95 97 Normal : 110/65 | 106 - | * 30 165/95 94 | Normal im 50 182/120 56 Coal miner years | | ' Foundry years Coal miner years , | | | ' Coal miner years _ * The subject was uncooperative The subject was 5 feet 2 inches in height and weighed 203 pounds 3362 62 Material may be protected by copyright law Title 17 U.S. Code Nov. 1949 TALC DUST EXPOSURES 363 Six had vital capacities considered subnormal of these 3 had enlarged hearts as determined by the formula mentioned above In this second group only one chest roentgeno gram showed abnormality which was considered stage pneumoconiosis The man also had lowered vital capacity but he appeared to be suifering no disability He had previously worked in the mining industry for five years See figure 2.) ) exposures restricted to that mineral In the New York mines and mills the dust was composed of equal proportions of tremolite and talc Porro et al 7 published illustrations contrasting the fibrous structure of tremolite with the granular nature of talc In the Georgia studies the dust was principally soapstone a form of talc but also con- tained 10 per cent tremolite The dust in the North Carolina studies was not tale but pyrophyllite and KERS EXPOSED \ miner years 3 years ears A years 19 years - FIG 2. This man is 49 years old and has been employed in the rubber industry for 24 years with an average exposure to pyrophyllite and whiting of 150 million particles per cubic foot He worked in coal mines for a period of five years His lungs show advanced pneumoconiosis diagnosed as grade III His vital capacity was 68 per cent In spite of the advanced pneumoconiosis and lowered vital capacity he showed no disability His work record shows that he has lost only three weeks from illness over the past 24 years Another group of 16 men engaged in the same rubber processes but with shorter exposure periods were examined in the same manner All chest roentgenograms were normal The producer of the talc discussed in this study stated that periodic roentgenographic examinations among his employees have failed to reveal any changes due to talc 12 DISCUSSION Previous publications reporting tale as a cause of disabling pneumoconiosis do not present furthermore contained from 25 to 35 per cent quartz In an excellent discussion of the entire matier Pendergrass and Robert 13 stated ... the occurrence of an asbestosis reaction following prolonged exposure to tale would seem unlikely Further controlled investigation designed to eliminate the possible complicating factors of quartzcontaminated dust and infection is however imperative before concluding with finality that the roentgen changes are the reflection of a specific and progressive fibrosis and that tale is the sole Material may be protected by copyright law Title 17 U.S. Code 364 JOURNAL OF INDUSTRIAL HYGIENE AND TOXICOLOGY vol 31 no 6 etiologic agent in their production In this regard it seems quite probable that the described coexistent nodulation may be silicotic in origin In the reported autopsy cases there had been other opportunities for the inhalation of dusts presumably contaminated with silica and in the mining of tale itself similar exposures have not been excluded SUMMARY AND CONCLUSIONS 1. A review of the literature indicates that dust exposures producing pneumoconiosis allegedly due to talc were not restricted to that mineral alone as tremolite pyrophyllite and even quartz were also involved 2. Physical examinations and chest roentgenograms of a group of 20 men exposed to talc dust hydrous magnesium silicate for periods ranging from 10 to 36 years in rubber inner tube produc- tion were normal for men of their age group and urban industrial environment Similar examinations of another group of 20 men exposed for periods ranging from 10 to 25 years to whiting calcium carbonate with minor exposures to pyrophyllite 65 per cent quartz and to talc in reclaiming operations disclosed all to be normal except one whose condition was diagnosed as pneumoconiosis stage III This man had the highest dust exposure in the two groups 150 million particles per cubic foot and had a previous occupational history of five years in miningmining 4. The findings of the present study indicate that long exposure to tale does not appear to produce pathologic changes in the lungs 5. Proposals that limits for silicate minerals be added to lists of maximum allowable concentrations should include careful definition of chem- ical and mineralogical composition REFERENCES 1 JOHNSON BERTRAND L. AND BARSIGIAN F. M Talc and Pyrophyllite Minerals Year Book 1946 Bureau of Mines United States Depart- ment of the Interior 2 DANA J. D Manual of Mineralogy revised by C. S. Hurlbutt 15th Edition John Wiley and Sons Inc. New York 1941 3 SCHULZ R. V. AND WILLIAMS C. R Commercial talc Animal and mineralogical studies This .. 24 75-79 1942 4 DREESEN W. C Effects of certain silicate dusts on the lungs This J. 15 66-78 1933 5 DREESEN W. C. AND DALLA VALLE J. M Effects of exposure to talc in two Georgia talc milis Public Health Reports 50 131-143 1935 6 EASON H. F. TRICE M. F. AND CARPENTER C. .: A Study of Effects of Mining and Milling of Pyrophyllite North Carolina State Board of Health Division of Industrial Hygiene and North Carolina Industrial Commission Raleigh > North Carolina 1939 7 PORRO F. W. PATTON J. R. AND HORAS A. .: Pneumoconiosis in the talc industry JR American Journal of Roentgenology and Radium Therapy 17 507-524 1942 8 SIEGAL WILLIAM SMITH A. R. AND GREENBURG LEONARD Study of Talc Miners and Millers in St. Lawrence County New York State Industrial Bulletin vol 22. November December 1943 9 Preliminary draft Proposed Ohio Industrial Public Health Hazards Code Ohio Department of Health 1946 10 Proposed California Safety Orders as amended Division of Industrial Safety California Department of Industrial Relations August 23 1948 11 Tentative Hygiene and Sanitation Standards Hygiene and Sanitation Section Division of Engineering and Safety Trenton New Jersey November 15 1945 12 Personal communication W. W. Magnus Eastern Magnesia Talc Company Burlington Vermont 13 PENDERGRASS E. P. AND ROBERT A. G Some considerations of the roentgen diagnosis of silicosis and conditions that may simulate it Radiology 50 736-745 1948 HIG HE effec of tin dustrial hy Thomas a tration cur of guinca bromide a Recently need for l pathologica mended thi of toxicity logical stuc establishing daily expos concen Briefer e contaminan in industria tions Frequ from the co In aviation because pas airplane unt the safety o pends upon air crew Th aviation ext responsibility Extinguish hydraulic fl which may i carriers cons logical stress insure the cc air crew in pheric contar detailed know to exposure 1 Presented Council New Received for * The opinio are those of th as necessarily 3 of the Civil Ae Material may be protected by copyright law Title 17 U.S. Code