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FILE NAME Owens Corning OC DATE 1935 DOC OC295 DOCUMENT DESCRIPTION US Gov Report - Effects of the Inhalation of Asbestos Dust on the Lungs of Asbestos Workers ~ . 2), a 3 U.S. TREASURY DEPARTMENT HENRY MORGENTHAU JE Secretary PUBLIC HEALTH SERVICE HUGH S. CUMMING Surgeon General 4 ^'s ae! Pt 2 aed po EFFECTS OF THE INHALATION OF _ ASBESTOS DUST ON THE LUNGS OF ASBESTOS WORKERS apt . ad - a t.7 \ strat .- . eet SS2 eC hate if Mpg Some ae i ae BY . atte vee ry 7 *** A. LANZA QUsi oo Assistant Medical Director -- vs WILLIAM J. McCONNELL . . a a Assistant Medical Director .~ J. WILLIAM FEHNEL Chemist Metropolitan Life Insurance Co. REPRINT No. 1665 FROM THE PUBLIC HEALTH REPORTS Vol 60 No. 1 January 4 1935 Pages 1-12 UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1935 For sale by the Superintendent of Documents Washington D. - + = - + = + @ Price 5 cents 01 501 0499 _ wpe oes 7 EDZILI INT v^ tan a^ ee ee , 3 sampai sasammpaipai aes aot Bae BL m^ el benotat benotat us 43 m sidion poi sampai iene 8G setur riding ta rastoinen aunt wil wil cu 2k tite fon, eleadthiek 1. : - te ete . ~- rf EFFECTS OF THE INHALATION OF ASBESTOS DUST _ 1. THE LUNGS OF ASBESTOS WORKERS . . ON Preliminary Study Rd By A. Chemist ant InsurMaendciecaCl oDi.rector woes, J. WILLIAM Chemist J. Lanza Assistant Medical Director William J. and 5 FEHNEL WILLIAM FEHNEL ew ( .. ee SY rers esOc See Aaeseres ~ McConnell Assist- Metropolitan Life Metropolitan a Seti ly abe ce ote va Co. was by the MINTRODUCTION MINTRODUCTION KLANTENA KLANTENA ah oe ara : Metropolitan tem jee wer oe E Insurance om approached paw be: In 1929 Metropolitan Life Insurance approached _, in officials representing the asbestos industry the United States who - were desirous ascertaining occupa of whetheranadsbestos dust tional hazard in their establishments so what was the nature of this hazard and what should be done to prevent or control it medical several articles About this time had appeared in English medical journals describing a pneumoconiosis due to asbestos dust While in one or two isolated instances the occurrence of this type of pneumo- coniosis had been described in American journals the industry itself appeared to be quite uninformed of the existence of any such occupational disease strani tt reference reference the The hazard of silica dust with special reference to the lungs has long been appreciated and a great deal of study and research has been applied to the problem in the metal mSitnaitnegs atnhde cBerrittaiinshotDhoe-r industriesandGrineoathter Bcroiutnatirniesthe TUhneitneadture of the effects of silica minions silicosis with the resultant extraor- dust expressed in the term tuberculosis is well known dTihneasrey efpfreecdtissphoasvietiboneentoaspsuoclimaotnedarwyith the inhalation of dust con- free silica in varying amounts The effects upon the pul- taining combined silicates monary tissue of dusts containingbut evidence is accumulating that still a fertile field for investigation distinct from certain of these dusts produce pathological results quite pneumoconiosis true silicosis The name asbestosis has been applied to the asbestos dust and it will be so used in this report Chem- caused by hydrated magnesium silicate ically the asbestos of commerce is a primarily of silica combined silica 44.1 perceinrtonmaagn-d consisting and water 12.9 percent while ferrous nesia 43 percent This commercial variety of nickel are present in small quantities 1 112414-35 oh Ot 01 501 0500 separ ~ a ASBESTOS 2 EFFECTS OF DUST ON THE LUNGS commonly chrysotile asbestos most encounteredis designated as and is one of the four varieties of the mineral serpentine in which it usually occurs in seams It should be bornein mind that silicosis and presumably asbes- tosis develops very slowly taking from 5 to 15 and even 20 or 25 - years to become established This rate of is influenced progress by the dosage of silica which the lungs receive and this dos- mainly age in turn depends upon three variables amount of silicain the the dust Individual quantity of dustin the air and the length of exposure might be included as a fourth idiosyncrasy variable however little is known of the variations in susceptibilityin those exposed to dust It might well be assumed that similar variables would influence the occurrence of asbestosis In places notwhere asbestosis mined or fabricatedin North America present there doesnot appear to be the clear clinical picture a communities w:hichso unescapable iinn with a true silicosis hazard communities mining suchas hard rock may , , be that some of the silicate dust typical asbestos plantsare of too recent origin for the to become manifest but this would olderminesor to all of the plants effects of a not apply to the it aid Jont fabricating Metropolitan The industrial health service of the Life Insurance Co. undertook the following investigation during the period from 1929 to January 1931 which included " October Canada conditions 1. A study of dust in in asbestos mines and millsin the andin fabricating plants along the Atlantic Seaboardin States United 2. Physical films examinations of asbestos workers including ray asbestos ' 3. A study of dust exhaustsystems designed to eliminate dust fabricating study Data on the plants only are includedin this are designatedin the report as plants A B C D and E. and Thisis a preliminary report A more extensive study of the asbestos industry is now under way DUST STUDIES Apparatus and methods of sampling the impinger 1 and the electric precipitator 2 were used for the collection of air samples for dusts at the breathing levels and in close proximity to the workmen Both of these forms of apparatus are adapted for this work as they are transportable easily set up and adjusted for the taking of the air samples at the proper level and are extremely efficient The impinger collects the dust by aspirating the air and then impinging it onto a flat surface covered by a liquid in a container The liquid used was distilled water containing 50 percent alcohol to . 01 501 0501 po cmenee weet tee WAR wear oe ee Eas see . . fb amen gaeeg cede ce EES ST alee Sr ree . mt ae =_ +; ws om . tL AAAA- t-- OF EFFECTS ASBESTOS DUST ON THE LUNGS 3 the solution of some of the dusts particularly any silica prevent which might be present The impinger was actuated by an electri- cally driven rotary pump and the rate of air sampled was measured by means of a resistance type of flow meter with an inclined manome- ter for measuring the pressure difference Each sample represents the dust collected from a volume of 100 cubic feet of air The electric precipitator is designed upon the Cottrell precipitator principle used for recovering dusts and fumes commercially This principle depends on electrifying the dust particles by making them an pass through electrostatic field and thus causing them to settle a of up out sheshe eett celluloid ' The electrostatic field is set by means of a transformer operating from the lighting lines on 120 volts alternating current Air is drawn through the apparatus by a small rotary fan run by a motor the quantity being measured by a flow and pipe of dust brushed from beams lines near the ceiling Samples also were secured for chemical analysis All samples were shipped to the industrial hygiene laboratory of the Metropolitan Co. and the to dust counts were made according the methods accepted by the United States Bureau of Mines and the United States Public Health Service 1 Particles in sizuep to 360 microns in the greatest diameter were counted Chemical analyses were made for total free and combined silica according to the accepted standard method of Hillebrand 3 In the first plant studied A only particles 10 microns and under in size were counted It has been demonstrated repeatedly that no silica particles exceeding 10 microns a micron equals millionth of a meter or thousandth part of a millimeter in greatest pdairatmeter enter the lung tissu ; for this reason the larger particles not considered when determining dust counts Later as usually are articles 4 English that it appeared from some of the published asbestos particles much larger in size were found in lung tissue it was decided to count all particles and make differential counts of all those 10 microns and under.,, cubic foot and the corresponding weight of the Total particles per relationship between the dust in milligrams were obtained Since no dust counts and the corresponding weights was found the weights are not included in the tabulations in this report Table 1 shows by plants and by departments the maximum and minimum dust counts in million particles per cubic foot of air Although the counts in plant A are of particles 10 microns and under and the electric precipitator were counted In addition Samples collected by both the impinger being projected upon a screen with a lantern- microphotographs of these dust particles were enlarged by measured with a ruler Knowing the entire enlargement by slide projector the enlarged particles being the original particle size 5 By the use of Hazen's 6 actual measurement it was easy to calculate be measured in this case microns are logarithmic probability paper the logarithms of the function to plotted as ordinates against the probability of occurrence as absciss^o t 01 501 0502 cae ee em ee oN yy + spa ws - - -- ee OL . 4 EFFECTS OF ASBESTOS DUST ON THE LUNGS and in the other plants are for all particles direct comparison is possible as in no sample taken were the number of particles 10 microns and under less than 94 percent of the whole .. - 6 heres ge lee a dy F i. Table Maximum and minimum dust counts in million particles per cubic foot of air by plant and department _ _ 1 . ad a The A B Plant Plant | . ' a Plant | Plant | * E Plant i ' - Department . * { 2 Fd Million | Num| Num- ber sam- of10 per| of|parti perbtearkenof parti per| ber of | of [foot . sam- F-:-- . NumNum clea ber under SAM- per plas Million | Million Num- . of cuble sam foot of a ++ part MillionMillion parti cubic foot of de Bir |, | Num- Million Million parti | cles foot taken ae ak: eg ber of sarb Million Million parti ples | clas per -- -- cubic foot of of . Birty fe mt t fegen dye - oot iff . 75-8 vay 8243 8243 i AK 8 8243 814-1536 ee 11 3 30 -82 326-76 326-76 326-76 14-1 ( 16-16 314-44 314-44 314-44 11 - 34 8834-10 834-10 8834-10 15 near 514-10 31816-7 31816-7 31816-7 1-7 s 8 1034-1934 2 one Included in spinning we on * Includes broad loom weaving . Whereas the dust in the preparation room is practically all due to asbestos the contrary is the case in the other departments In the carding spinning and weaving rooms asbestos comprises about 25 percent of the material used On special jobs the percentage of asbestos may be higher but in general the figure quoted is approximately correct the other material consisting principally of cotton In the insulating departments of plant A asbestos is but 5 percent of the total material used In the molded brake and clutch division of plant D asbestos comprises about 25 percent of the total material The actual exposure to asbestos dust therefore is considerably less than is indicated in the dust counts in table 1 CONDITIONS IN THE PLANTS The processes in these plants were very similar to those in cotton mills in general For illustration the process in the preparation room of plant B is here detailed at length Asbestos is received in bags These are emptied upon the floor and the asbestos is shoveled into pug mills and run for about 5 minutes in order to crush and open the fibers From there the asbestos is shoveled into trucks and wheeled to hoppers with either horizontal or vertical openers similar to those used in textile mills After passing through the opener the material is discharged into trucks Waste manufacturing material is first run through a garnet machine and 01 501 0503 we . vce # , Hamb = yer MAMAS cele a nee eT oe o- Sire F PS Benge wes EFFECTS OF ASBESTOS DUST ON THE LUNGS 5 . material discharged into trucks which are wheeled to the openers and the material is fed into these in the same manner as is the new After being discharged from the opener the material is put onto a vibrating or shaking screen where the long fibers are picked off by a suction hood and blown into a bin to be used again in textiles The short fibers falling through the screen are either sold as such or used in making an asbestos cement The cotton is received in bales opened and also run through vertical openers It is discharged into trucks The filled trucks from and horizontal the vertical openers containing either the asbestos the waste fiber the cotton or material are taken to separate storage bins As needed these materials are weighed and dumped onto the floor in proportion to the mixture desired and the resulting mixed . materials are then passed through a mixing picker As this mixture is discharged from the picker it is sprayed with a light mineral oil is The material then taken by a mechanical conveyor to the storage card room bin in the Two of these mixing pickers discharge onto this conveyor _ system while a third machine is equipped with a suction device which conveys the material to a storage bin in the card room The object of the two systems is to facilitate the handling of two grades of material at the same time The third machine is not equipped with an oil spray The object of the oil spray is pri- marily to entrap the small asbestos fibers and hold them enmeshed in the cotton fiber throughout the processes of carding spinning and weaving Incidentally it is apparent that it also diminishes the amount of dust The material is saturated with about 4 percent of oil at this point but by the time it reaches the looms the oil had diminished to less than 1 percent While mineral oil was used in the preparation room of plant C it apparently was not as efficacious as in plant B. In plant E oil was not used nor was there any attempt at humidification or any system of dust exhausting Carding machines were fed by hand In plant A there was a humidifying ventilating and heating system while plant B depended on natural humidity In plant E the carding machines were equipped with a exhaust system but it was not efficiently used In plant C carding was done in 2 buildings 1 of which was equipped with an conditioning system and in both a buildings the machines had exhaust equipment Two plants B and C had artificial humidity installations in their spinning rooms In the former the temperature was 76 F. relative had humidification system in humidity 78 percent One plant C a and also in the weaving department where the twisting department of the relative humidity was 76 percent with a bulb temperature 69 F. as compared with relative humidity of 44 percent in the weaving room of plant A. 01 501 0504 6 EFFECTS OF ASBESTOS DUST THE LUNGS Aside from plant E it would appear that the dust hazard was not excessive except in the preparation rooms of plants B and C. The dust counts are interesting too when considered in the light of the permissible standard for granite dust established by the United States Public Health Service 7 namely about 10 million particles 10 microns and under per cubic foot However we are not justified in assuming that because available information suggests that asbestosis is a milder disease clinically than silicosis the threshold of permissible dust counts is higher Asbestosis appears to be patho- far logically different from silicosis and the experience so does not warrant an attempt to define a standard of dustiness for asbestos dust jog ers i weblion, ers : Perera oc ^ nta DUST CONTROL t ! B N k aa ho ld et noi^-oqone di sonh as local exhausts measures humidification .. 4. Various tended such oiling and as Nevertheless evidentthat they dust Nevertheless humidification it was to reduce the were only partly successful If it is expected to control dustiness in these plants final reliance must rest upon properly constructed exhaust in equipment In plant one department an experimental installa- tion was set up In spite some obvious faults this equipment on the basis of comparative dust counts reduced the dust by 50 percent and with further alterations will probably be 75 percent effective In this case such a reduction seemed quite satisfactory It is neither practicable nor economically desirable to install such equipment as will make the air entirely dust free The normal defensive mechanism of the body takes care of a fair amount of atmospheric pollution It is when the body is exposed to an excessive amount of dust that this defense mechanism breaks down The application of exhaust equipment to textile machinery involves considerable difficulty especially where the construction of the plant is such that it is not possible to apply down suction to the looms It is desirable to install exhaust apparatus in any plant on an ex- 1 perimental basis first and then check its efficiency by dust counts This practice will result in saving a needless expenditure of money PHYSICAL EXAMINATIONS e ray films were made of 126 persons 108 men 18 women working - in asbestos plants in the United States All but five of these were given physical examination The cases were selected more or less at random from among those having more than 3 years of employ- SR ment in the industry It was soon obvious that the early diagnosis of asbestosis must rest to a large extent on ray pictures of the Tre chest As in the early stages of silicosis the clinical symptoms of the asbestos workers were usually indefinite and inconclusive The interpretations of these films are based on the readings of one competent roentgenologist but they have been reviewed by several 01 501 0505 w oo wee ~ . EFFECTS OF ASBESTOS DUST ON THE LUNGS 7 others experienced in this field The differences of opinion were of a minor nature and there was general agreement as to interpretation The films were read conservatively taking into account the physical examination and the age of the individual and were classed as positive only when there was no major disagreement All examiners were guided by their experience in silicosis and other types of pneu- moconioses The films classed as negative for asbestosis were further subdivided into doubtful : and negative Only time can tell whether the individuals classed as doubtful are progressing toward a definite asbestosis Particular attention was focussed on the presence or absence of indications of tuberculosis and in this respect all the reviewers of the films were in accord With the unhappy experience of silicosis in mind it was felt that a great deal of care should be devoted to ascertaining if possible whether or not asbestosis pre- disposes to tuberculous infectionaadisastrodajinfetctionadeisastrodajte sebi ni s''T -The cases of asbestosis were divided into two classes first stage and second stage The first stage embraces those who show by ray examination definite lung pathology sufficient in extent to warrant a diagnosis of pneumoconiosis but who have no definite symptoms The second cases exhibit more extensive lung pathology and also definite symptoms . ~ All these individuals' were actively engaged iin n factory work and it was not practicable to make any distinction on the basis of working ability or disability Had any individuals been found who exhibited extensive pulmonary involvement and marked physical disability or total disability they would have been classified as third stage but no such cases were found Of the total of 126 ray examinations 4 were diagnosed as second asbestosis 63 as first degree 39 as doubtful and 20 as negative There is a definite increase in the percentage diagnosed as positive relation to the years of exposure as shown in table 2. Small numbers make it impossible to determine how far the factor of age enters into this increase Table Classification of cases by years of exposure Years of exposure Percentage Number Positive | Doubtful | Negative Over 15 years 5.2... eee eee cnc n eee ceweuee 10 15 years oo eke eee 3 to 10 years Under 5 years een een w ence nee erecenccece 5889 5889 5889 5889 Total examined . 2.2.0... c eee cece cee ee nce fee seen eene ve 21-856 21-856 21-856 21-856 21-856 1 3 732 10 39 13 2 3 12 20 Part time 11 not continuous ? Ode asbestos worker second stage retired of his own accord to this study but is still active about his garden because of old age 10 years previous . 01 501 0506 Ge ee enn mene eummnaarenr es cere Stine ewe tmwdnens > myn NS mig aif te ee a oe antes en 8 EFFECTS OF ASBESTOS DUST THE LUNGS OfOf the 64 persons given physical examination and diagnosed as having positive asbestosis only 8 were entirely free from symptoms while 10 out of 37 with doubtful and 7 out of 20 with negative diag- noses were free from symptoms Dyspnoea and cough were the symptoms most complained of but none of these cases exhibited the urgent or evident type of short wind seen in true silicosis Several of those classed as negative stated that they were short winded and were so recorded but too much emphasis should not be placed on statements of subjective symptoms During the progress of the study physicians were practicing in the communities where asbestos workers lived were questioned and stated that they did not find an unusual amount of tuberculosis among these workers The . contrast between this state of affairs and that found in a community with : a silicosis hazard is notewort2h GSy Lae eate eate ... The incidence of tuberculosis based upon films is given in tuberculosis examined employ- table 3 40 of the 67 lessthan ment in TABLE Incidence - the industry wo eh Anes, 3. had Nr tal of 15 years of ele vee # yo . 7 T Positive Doubtful Negative Tuberculosis Tuberculosis active -- Tuberculosis Tuberculosis 7 1 2 11 0 1 87 ae 2 This case was diagnosed as probably active on the ray ^ ndings Table 4 gives information as to physical signs of chest trouble Table Chest findings Positive | Doubtful [| Negative Physical signs of chest trouble .....----- ec nsec ences ween ence enon No physical signs signs 0022. eee cone cee cee eee rece eer ecse cere nne Not examined . cere ce eee en- see eee wae nena seneceeecces, TotalTotal .. 1 At least 6 of these showed no evidence associated with asbestosis 12 of these not associated with usual signs found with asbestosis 16 of these not associated with usual signs of asbestosis 133 3376 3376 3376 19 +7 28 13 g q 39 { 20 What significance if any can be attached to the presence of asbestos corns on the hands of workers appears doubtful as 18 percent of the positives 12 out of 64 and 15 percent of the others doubtful 7 out of 37 negative 2 out of 20 showed such corns \ Each roentgenologist who reviewed the ray films called attention : to the fact that these films indicated a very unusual incidence of | enlargement of the heart It is probable that this is a compensatory enlargement due to the additional work put upon the heart in efforts 4 01 501 0507 EFFECTS OF ASBESTOS DUST ON THE LUNGS 9 to pump blood through the fibrosed lungs Itis possible that not effects beenpaid sufficient attention has upon the heart to the je otfe the pneumoconioses Many workers had changed from one department to another and from one plant to another during their years of employmentin the asbestos industry Since the amounts of dust collected at the only departments time of this survey in the various are known thereis no way of knowing the average amount of dustin the atmosphere inhaled by these people over the years of their employment Conse- individual definite correlate possible quently it is not to of dust ~~. amounts 3194 lh exposure SUM cegenlgg te eee se exposure tian tes cases with h ibada ibada we light cLAIMS asbestosis To throw Insurance ibada . 3194 ibada ibada tae ee 7074457 eee on the relationship between and pulmo- disability companies nary tuberculosis an analysis of death claims and manent claims was madein regard to group insurance and having available figures total and percarrying There were 2,099 lives involved with a total exposure of 7,019 life- years The death claims are so small in number that reliable con- clusions cannot be reached from any subdivision of the figures The same is true of the sickness claims under health insurance The number of claims for respiratory diseases is high in two of the plants studied but low for the others as compared with the Metropolitan experience of 1927. However during the latter part of 1928 and the first part of 1929 there was an epidemic of influenza The records of one establishment plant B showed that 6 of 36 death claims and 8 of 10 permanent and total disability claims were listed as due to pulmonary tuberculosis This appeared to be an inordinate amount of tuberculosis from this plant However many of the employees were Negroes and also tuberculosis claims are generally high in this section of the country Realizing the difficulty in diagnosing pneumoconiosis and the tendency to confuse it with tuberculosis these claims were studied individually The physicians who had treated the individuals were interviewed and the hospital and sanatorium records including available ray films were investigated with the following results Death claims 1. A typist not exposed to dust died of pulmonary and intestinal tuberculosis 2. Colored male age 27 worked in asbestos 1 year and 8 pulmonary months died of tuberculosis following a hemorrhage was in sanatorium 10 months Also had a four plus Wasser- mann No evidence of asbestosis 3. Colored male age 32 workedin asbestos plant 1 year and pulmonary 7 months died of tuberculosis after 1 month in hospital Cavitation both lungs no evidence of asbestosis e 01 501 0508 10 - : OF EFFECTS ASBESTOS DUST THE LUNGS in asbestos - 3. 4. Colored male age 34 worked plant 2 years and 275-6 2 months His physician believes this was a case of uncom- plicated tuberculosis Was not inmate of hospital or sanatorium No information coulbde obtained on the other two cases Total and permanent disability claims plant - in 1. Male employed asbestos plant years . His physician _. states that he first came under his observation with an old estab- lished case of tuberculosis about 2 years after asbestos employ- glands started Also had tuberculosis of the kidney and cervical glands glands glands a . , . ns earePee CY ee . ws ... 2. Male employed in asbestos plant 8 months His physician 7 states finding of old fibroid tuberculosis with tubercle bacilli in sputum No ray available but according to physician as- oe bestos bodies were found in sputum.v . oO 3. Male 10 years employment Two physicians who treated + 108 him at different times now inclined to believe this man is not has time physician .. -see tuberculous but asbestosis at time of investigation investigation His * : White male was reexamined at of investigation color His physician husky looking good color no reports well nourished _.. cyanosis no clubbing of fingers diminished expansion incessant -*"" cough ray shows fine mottling disseminated through both -e~ lungs No evidence of tuberculosis : Probably a second stage I + plant asbestosis 3% old asbestos boynor ora sanato- 5. White male 13 years in asbestos Is now in sanato- rium An interesting case His physician states that he has ex- tensive asbestosis and pulmonary tuberculosis cavity in right lung sputum loaded with tubercle bacilli and asbestos bodies believes tuberculosis long antedated asbestosis This patient is progressing in a satisfactory .. manner It was not possible to locate the other three cases of total and permanent disability who had been diagnosed as having pulmonary tuberculosis On the basis of the information obtained the deaths in claims cases appear to be due to uncomplicated tuberculosis three of them were Negroes who were probably tuberculous at the time their employment in the asbestos plant commenced Of the 8 disability claim cases 1 was uncomplicated tuberculosis and 2 were uncomplicated asbestosis who were put on disability because of a mistaken diagnosis of tuberculosis In this same community we know of one death due to uncomplicated asbestosis in an individual with many years employment in the industry. CONCLUSIONS 1. Prolonged exposure to asbestos dust caused a pulmonary fibrosis of a type different from silicosis and demonstrable on ray films Clinically from this study it appears to be of a type milder than silicosis 2. Cases of definite cardiac enlargement were frequently found to be associated with asbestosis "Personal communication tek, 01 501 0509 3 Oh ee tee ne meet tte Air a Sr * . * Shib o Te. - . - a EFFECTS OF ASBESTOS DUST ON THE LUNGS 11 predispositionto 3. A tuberculosis to asbestos ~ due dursetsulted of indicatedin this study 4. Asbestosis as observedin this series asbestos cod cases had not was not . cadet in in marked disabilityin any case 5. Itis not known how much asbestosis may add to the mortality of pneumonia and acute nontuberculous pulmonary infections 6. Itis not as to establish standards for the asbestos practicable as yet dust content of air 7. The amount of dustin the air in studied can reduced the asbestos plants be substantially ....... wet a Ci AS : ane gM Cee a en tebeel tat aye tesa ok fe RECOMMENDATIONS asti HOLE N67 < It recommended recommended HOLE Sorta Me sey cat andalu5 andaanlud5alu5 andalu5 mre? : ees piblre* recommended &Itis seriously vente problem dustcontrol 1. That the industry seriously facethe of in asbestos plants cana min yolm cook muddlede 18117 13 1989gik^ U ; 2. That new employees be examined physically including ray examination employment for of the chestand rejected for in tuberculosisor pneumoconiosis physicaly physically qui if theyshow every every physically preferably 3. That employees be examined every year but at least every 2 years this examination to include an ray examination of the chest 4. That the industry sponsor studies on known cases of asbestosis as well as studies on effects of asbestosis on the heart and circulation ACKNOWLEDGMENTS The authors wish to express their sincere thanks to all those who aidedin making this study especially the officials and em- possible ployees of the asbestos who cooperated to the fullest extent companies and gave every facility for securing data also to Dr. Pancoast of the University of Pennsylvania for his interest and valuable advicein interpreting ray films and to Dr. F. V. Meriwether of the United States Public Health Service surgeon in charge of the United States Picher Bureau of Mines Cooperative Clinicin Okla whose inter- followed pretation of all the ray films listedin this report is followed Ap- preciation is also expressed to Dr. W. Atmar Smith and Dr. Kenneth Lynch of Charleston S. C. for information and advice particularly asbestosis as to the pathology of * to Dr. W. W. Wild of Charleston S. C to Dr. Joseph H. Wyatt of Newark N. J. and Dr. H. H. Fellows of New York for assisting in interpreting ray films to Dr. Paul O. Snoke of Lancaster Pa to Dr. R. H. Stevenson of . Danville Quebec Canada and to Dr. L. U. Gardner and Mr. Donald E. Cummings of the Saranac Laboratory who have undertaken the study of the pathological effects of the inhalation of asbestos dust A sbestosis bodies in sputum and lung By Kenneth M. Lynch M. D. and W. Atmar Smith M. D. Jour Am Med Assoc Aug. 30 1930 vol 95 no 9 pp 650 861 01 501 0510 . ~ PPat+ ometrSpa pan mn nee n Mw taee Hee FWA om gp ye yee Ne . eg atiaaiiebeat ~~ ve >eee ro ~ . tee . ' 12 EFFECTS OF ASBESTOS DUST ON THE LUNGS through animal experimentation with ~ the aidofa grant from the _ Metropolitan Life Insurance Co. reerwie. Tet, t " REFERENCES 1 Greenburg Leonard and Bloomfield J. .: The impinger dust sampling ap- paratus as used by the United States Public Health Service Pub Health . Rep vol 47 no 12 Mar. 18 1932. Reprint no 1528 2 Drinker Philip and Thomson Robert M Determination of suspensoids by alternating precipitators Jour Ind Hyg, vol VII no 6 June 1925 3 Hillebrand W. F The analysis of silicate and carbonate rocks Bull 422 United States Geological Survey Washington D. C. ; 4 Cooke W. E Pulmonary asbestosis Brit Med Jour Dec. 3 1927 5 Green H A photomicrographic method for the determination of particle size of paint and rubber pigments _ JourFranklin Institute 1921 pp Sons Whipple Wiley 6 Russel G. statistics Exposure gra1n9i2t5e BriPttuenb Health tradNeos. The 7 ` Vital John and New York C. p 451 Britten H Thompson Thompson L and Bloomfield J. A. .: Britten R. H Thompson L R. and Bloomfield J. health of workersin dusty II to siliceous dust 187.1929 187.1929 Bull _ ata zdaj zdaj ats vee industry ivan aes Ps J13 oe a sayin: Sete? : chee WIL bc toe, wg + > ge aesqe re rete me 10% ws ANS ne 01 501 0511