Document G57gD0LZj6mgRymvjeNpp5rDn

FILE NAME: Garlock (GAR) DATE: 1947 July 11 DOC#: GAR028 DOCUMENT DESCRIPTION: Memo Supplementing June Report "Preliminary Dust Investigation for Asbestos Textile Institute" with Report Attached J2ZI PLAiiniiFFS f [ EXHIBIT ! - T'nuSTTiTAL HTOITMT TOOITDATIOX O* .VTRICA, XfC hhOO f i f t h Arams Pittburgh 13, Pa. Jnljr 11, 19^7 Maor*odna on 71ant of Th Oarlook p*oklag Coopaagr 8uppl*niing Th OtMTll PtMrt Prollnlnary TNit Investigation for Asbestos Toactllo Institute* Of Jaso. 1947 JoiU m m H ilo p lan t 1 designated m 0 l a the ganar*! report aad an appraisal o f It dastia 1 snanerltad la th at oolunrn o f Tabla 1 pago 5* Th dlffereaa htwn th rain aad tho of othr good plant ara, oa th whole, aat lgnlfleant and v* rets thl plant as average *good.* Hovvr, this do aot aena that dat control la entirely satisfactory In a ll respects a lndloatd la th* genaral report. Thr it an lnsaffloleat minbr o f dnt ooaat In tha oonpany fll to oonatltut aa adequate raeord of dustin. hemal rarlntleas require a nubr of eount at aeh operation to provide * useful average. Oar ovn slngls dust counts t&Vrsn at th tlaa of th v is it or giran below. Timber 1 ?. 3 4 Zlapeed Tlaa (Mins.) 5 5 5 5 Operation At operator nd o f 4 oardlng machine* (* . 1 , ? , 7 ad 8) General a ir In alsloe of tw isting aaohlaoa General a i r , along row o f loooat aost windows opa along th working a la i General a ir in a sla s o f spinning frenes IVist 1.5 3.0 3.1 1.7 iDhi-titiae, EXHIBIT NO^ZL L. FIELDS d e p o sit io n E X H IB IT 0 03840 2&Z1 'ost* al htoith: rxnnuTio o* .vtoica, iic I*t - (*LEXAHirI<BiIiTfFS l I M O O flfth Arsine Pittsburgh 1 3 , ?, Menoradua en Plant ef Dm Oarloek p*yla Conpsay Suppleeentln* Th July 11, 19*? g t a r s l B ttflrt Prtllainary !>it Inrastlgstlon fe r Abstes Tentile Institut" Of June, 19*7 Du U m u Thls plant 1 dsigntad m 9 la th *nr<0 report nd en appralsal e f Ita tastine* 1s nanerltsl la th*t oolumn e f tabi* 1, pece 5. Th diffrence betveen thsae relus* aad thoss e f ethr ood plants are, ea ths vhole, art sign ifierai and ve rate th ls plant as etra "oed." Koverer, thls do aet area thnt dust oeatrel 1 eatlrey eetisfaetory in a il respects as Indiente) la th* enarri report, There 1s sa ia m ffle le a t aunber e f dust oouats in ths eoapsay fila s to oonstituts aa adequate record of tastine**, Sornal variations rsqulre a irenbsr of oouats ai saeh opsratlaa te prerlda usefal erer.y*. Oar ova stagi* dust nouais taiesa et th ila of th r ia it ere glrra bslev. fcabar 1 ? 3 h Zlaptsd Tlaa \Hlns.) 5 5 5 5 Oseratlone rut At opereter end of h earding rmohlaas 1.5 (*0*. 1. ? , 7 d 8) Oenaral air in alslee of tvletln * 3.0 aaehlaas Oenaral a ir , sien rev of loonst aost 3.1 vlndove opea along the vorklng alelas General a ir in aslas of spinata* fraaes 1.7 EXHIBIT N O ^ Z . L. FIELDS ___________ , 0 03840 2 !\it Contro! Franila Oardlnf duat oontrol la dlaouaaad on pocaa 7 nnd 9 of tho conorai report. Boforano# la n*do- to th* axhanat ajrotas in thla niant vhlob aonoopllahat as fond dnat ooatrol no alnoat a il tbo othor *<ood* planta bat at ozhaaat rataa thnt veuld not bo praotlo*! for oth*r nartham planta. Tho duot oollantoro la uoo ai thlo plant ir> of *onldor-blo Interoot baeaaao tbojr laoludo ivo tjrcea not ln nao la ta/ othor plant (Air Mat and .Faraona) baooaao eooaenigr thoofbt to bo lapraotlool. foat data on thoao nnlt vould thoroforo bo raloablo. laclnoorlnc atndloa plnaaod for tho Ion to n lnroatlfotloa o f part Inalar lntoraat to thla plant and oatllnod ln tho conor*l roport roi doot ooatrol la rparation, tvlatln c nnd ve-rln *, ad afflatene? of daat eol^ootoro. J la al In tho nodloal aootlon of tho coneral rport reforaneo la nodo to tho aererai ooopanle vho haro ao InforaatloB aa to tha laoldonoo of potoatla1 aaboatoala la tholr niant. Thla Marenay la ono of thoao a'' thoroforo vlah to nndaraooro bora tho roeoanaadationa ceaeeral'VR porlodle r-ray oxonlnatloaa dlaouaaad partlenlnrly en paco Ih to 18. M.C.T., Booaon Hard Faclaoor 0 03841 PLAINTIFFS ) a m i nnxjsraiAL hygiene founiation of Am e r i c a , m e EXHIBIT MtOO Fifth Aveoua Pittaburgh 13, Pa. REPORT Of FREUKDiARY COST INVZSTIGATICW FOR ASBESTOS TEXTILE INSTITOTS JOKE, 19*7 RF WjCLt Heaeon Head Engineer Industrial Hygiene Foundation of America, Inc. By John F, M c M a h a n _____ Managing Director June 18. 19*7 ) EXHIBITNO I I - L. FIELDS 0 03842 REPORT of PRELIMINARY DUST SURVEY for ASBESTOS ITTITIE IHSTI W IB June, 19A7 O B J E C T Of I H E 8 TI 0 ATI 0 H This project was a preliminary larestigaticn at the asbestosIs problem in textile plants of members of the Asbestos Textile Institute, with the lsmedlate object of defining the specific nature and the magni tude of the problem in all its phases. From such a definition, the char acter of a long-term project could be outlined. An original objectlre of moot immediate importance vas to facilitate the exchange of Information between member companies on successful methods of dust control and othervise to promote a general laprorement in that field. BUMHARI The facta upon vhich this report is based vere obtained on rlslts, during the past three months, to all plants of Institute members (except one, vho wished, the rlslt postponed to a later date). Complete cooperation vas extended at all plants. Dr. C. Richard Valmer, Medical Director of Industrial Hygiene Foundation, participated in Ylslts to three plants and in development of the medical concepts of this report. The problem is seen to be composed at three aspects vhich are discussed in three sections of the report and sunaarlted herewith, as ERMHEEHUU}, MEDICAL, and PHYSICAL TE8TXN0. Preliminary Duet Survey for Aebeetoa Tortile Institute O June, 191*7 Engineering. -- Mechanical methods vere seen In use In cne or mare plants which effected practical dust control In all operatioca, bringing duet concentrations down to five million or lower vith one or two exceptions. It Is proposed to prepare formal detailed descriptions of these methods for gener al distribution to members of Asbestos Textile Institute. Medical Suuerrlslcn of Workers. -- Only five plants have had any medical x-ray surveys of employees. In ths others, therefore, there Is a serious lack of Information as to the Incidence of asbestosle. The lack Is more serious, In a sense, because In most of these plants no condensable cases of asbestosle have occurred to drew attention of top management to the problem. While the medical survey conducted by 000 plant recently shove only about three per cent of the employees with asbestosIs, two other plants appear to have about 20 per cent of their employees affected. Medical supervision of workers In this Industry is of utmost im portance for the protection of both employee and employer, not to mention other considerations. Therefore, It Is strongly rscasmended that each plant Insti tute a program of medical and x-ray examinations of all exposed workers as early as practical. Physical Testing (Dust Counts, etc.) -- The "maximum permissible dustiness" for asbestos Is commonly taken to be five million particles per cubic foot. This represents good attainment In the dust control program. It is em phasized, however, that dust elimination to this extent does not positively In sure that no aebestosls will develop In some workers after a long working life (greater than 20-25 years). Scientific evidence Is obscure an this point. It Is recommended, therefore, that studied be Initiated aimed to develop another D 03844 Preliminary Duet Survey for Aabestos Tortile Institute, June, 19k7 yardstick, because It is suggested that vhen control below five million is attained, present dust count methods m y not properly measure the remaining hasard. A detailed summary of reccosendatioas for a long-term investigation is given at the end of this report. D 03845 k. Preliminary Dust Surrey for Asbestos Textile Institute, June, 19^7 I- gyqiHBERIWO PHBSBTT MOB OF PUgf CCHTBQL Practically all plants visited hava had cos or more dust count sur veys made of their operatlcos and these data vers araliable far the present study. In addition, a fsv samples were taken by the Investigator In aost plants. These records vers studied and a range of concentrations Judged to be most representstire selected for the suanaxy given In Table I. Where relative ly extreae values appear It is an Indication of too fev data to permit a closer estimate. figures In the last column are selected to Indicate the magnitude of readily attainable dust concentrations vlth dust control measures now In ccmon use; or Judged to be most typical of an operation vhere no special dust control measures ars employed, e.g., ring spinning. Discussion of Concentrations The available dust count data for operations In the preparation roon are highly variable and reflect the poorer accuracy In sampling inherent In operations that are Intermittent and miscellaneous In character. These figures are, therefore, considered ouch less reliable than those far other departments. The figures far carding roon dustiness indicate that vlth reasonably good enclosure and exhaust of the machines, concentrations veil below three million are obtainable, four of the plants visited exceed the five million limit materially. All the data for mule spinners exposure indicate a vide variation in dustiness, ranging from tvo to eight million, but the volume of data are not D 03846 Preliminary Duet Surrey for Aabeatoe Textile Institute June, 19^7. Preparation Carding Mule Spinning Ring Spinning Twletlng Wearing Spooling, Winding TABU 1 PRESENT STATUS OF DUST CONTROL IH DIFFEREHT FLA1TTS: DESCRIBED IH TERMS OT AVERAGE DUST COUNTS A B C D X P 0 H 1-3 5-7 3-9 * 1-8 2-7 m 2-3 1-2 IQ-23 U-12 1*-J 2-* 2-3 2-3 W 6 ?-T 2 m 2-k 1-5 1-U 3-5 1-2 2-8 8 2.6 *-? 5-7 2 ?-8 2-A 2-10 1-2 1-5 11-15 2-5 W 2-10 I 90 30-50 m 13-18 13-18 m Moat Typical J vlth ^^Contro^^ 7-11 Belov 7 *-17 2-3 8 5-6 * 3-5 fc-9 k-7 2-1 1-3 2-U m 2 2-7 2 5-7 ___ l___ . . ? . m o o to oo *sj VJI Preliminary Duet ftirvey for Aebeetoe Textile Institute, 6. June, 19^7. great enough to yield a good average. Concentrations for ring spinning vary from one to five million although there le no strong Indication In the available data at narked differences between this qpezntlon and oule spinning. lhere is a similar vide variation in data for twisting (two to eight Billion), but there le sane Justification In these data for the opinion widely held that this Is one of the dustier operations In the finishing end of the Bill. It Is believed that occasional high values In both ring spinning and twisting reflect In sooe cases the ea&pllng procedure. If the large implnger Is naln- talned In one location and there Is a strand breakage In that lnaedlate vicinity, the resulting vhlpplng dust will be reflected In that single sample and would not, therefore, be representative of the worker's exposure. } Dustiness In weaving operations reflects the use of water for dust control In sons plants and exhaust systems In others. The lowest concentra tions of one to two million obtained In Plant A reflect highly efficient wet weaving methods there employed. Concentrations lees than four to five ml111on are readily attainable by local exhaust methods as indicated by the reeults in several plants. Ibe d a m for spooling winding operations are included for cco- pletenses, but reflect miscellaneous operations and conditions. The dust re ported Is often due to the effect of other machinery in the eaae rooo. Those canalderations therefore affect the reliability of theee dam, as in the case of operations in the preparation rooo. 0 03848 Prallrslnary Duet Surrey far Asbestos Tbxtile Inatitut, 7. June, 19^7. m S T D T O BUST CONTROL PRACTICES Th following discussion of dust oontrol practical In the industry 1 merely an outline. Tb he useful to thoae who are responsible for the engineering In each plant, they will need to he set forth In the f o m of detailed specifications describing details of construction, specifications for sheet aetal contractors, for purchase of fans of proper capacity and far deelgp and operation of dust collectors. Preparation Highly variable practices prevail In different plants and the mis- eellaneous character of operations vlthln a single plant makes It Impractical to fomulate annjr general statenants. However, it nay be said that such con trol as is realized results fron ths use of nodem equipment that is veil en closed and vixlch usually Incorporates pneuaatlc conveyors vlth celling con densers. The large movement of air Involved In p n ^ m t l e transport serves the useful additional purpose of preventing the escape of dust from the primary equipment. Discharge of stock from celling condensers into bins, stock boxes, or feed hoppers Is a dust usually not under control. The blending operation is another source vhlch is often not satisfactorily controlled. Vlth the ex ception of these two cacxaan operations, noet of the duet control procedures re quired vill be more or lese apedflo for each plant. Carding Aa has been noted, reduction of duetineae In carding to concentra tions of three million or lees Is easily attained by good enclosure of the -- and oarefully designed exhaust. Moreover, experience of several D 03849 Preliminary Dust Survey for Asbestos Tortile Institute, g June, 1947, companies proves that it does not Interfere seriously vlth manufacturing operations nor vith quality of roving produced. Our investigations indicate the superior advantages of having side- vails of the enclosure of vood to facilitate email clearance by rubbing con tact at the edge of the main cylinder, thus avoiding excessive air Infiltra tion at that point. Vood covers have Hie advantage of resistance to crushing, vhleh vas evident in installations vlth sheet natal covers. Connection of the enclosure to the exhaust system by means of chan- bers of aspls dimensions, l.e., large croes-sectional area is of major im portance to avoid localised high air velocities close to the vebblng in the main cylinder. This detail vas not always observed. ) In view of similar degrees of success, Judged by dust counts, be tween various installations, the best criterion of superior design as to de tails of exhaust from the machine vas in the relative economy respecting volume of air exhausted per machine. Our observations indicated rather ex treme variations as indicated in the following table of exhaust rates per carding set in five representative plants: Plant A B E O E Air Exhausted 1500 cfm 2200 cfm 3800 cfm 5*00 cfm 2000 cfm It is apparent from this investigation that 2000-2500 cfm per set of breaker and finisher cards is ample exhaust capacity if the system is properly designed. 0 03850 Preliminary Duet Surrey for Asbestos Textile Institute. June, I9U7 All five of the systems described in the table serve their purpose satisfactorily from the viewpoint of operation, but it does not mean that they would be equally satisfactory to others. Oras the plant vith high ex* haust capacity (0) has a unique interplant tunnel connection, so that excess heat from another plant supplies replacement air without added cost, for heat, or winter discomfort. Plant H controls dust by completely housing each pair of cards In a spacious room, exhausted at a rats of 2000 efm. Sidewalls are easily remov ed for repairs. Most plants would not prefer this arrangement. Aa far as the duet count data can show, the card room of Plant B with 2200 efts la equal If not superior to that of Plant E with 38OO cfm, a recently installed system. The fundamental features of best card dust control systems observed are ae follows: 1. Wood enclosure with hingeing arrangement. 2. Liberal clearance between worker rolls and curve of cover permitting air passage at low velocity. 3 . Large chamber connection on cover, to duct. 4. Duct branch not over preferably A". 5 . Ho blast gate dampers In branch line. 6. Exhaust influence over comb, either by extension of main cover or by separate hoods. 7. Exhaust specs under machine, not over A" duct. 8. Enclosure and exhaust of feed hopper, not over A" duet. TWo installations Include an exhaust branch to prevent the eecape of dust originating in the face between the ring doffers and the main cylinder. 0 03851 Preliminary Duet Surrey for Asbestos Textile Institute, June, 19^7 One pleat bee Installed ventilation for their ring spinning frames vhlch management believes has reduced dust la this operatlcn. It ccaslsts la e series of exhaust openings under the frame, near the floor, running the length of each frane. Time did not permit demonstrating to our own satisfaction whether a measurable Improvement had been effected or not. This should be done by a series of dust measurements vith exhaust on and off. The volume of air exhaust Is Insufficient to effect a true local ex haust action, and If It Is effective It oust, therefore, be an effsot of sizzle dilution, TVlatlng Interest In control at dust from twisters Is widespread In the In dustry and Plants A and B have Installed an exhaust system like the one de scribed for the spinning frames in Plant A, Bre again the operators believe a marked Improvement has resulted. Bust count data is needed that will measure the degree of improvement. Winders Cop winders have been exhausted in Plants A and B with reports of beneficial reduction In dustiness. We do not have quantitative data on this point. The exhaust arrangement far Poster winders was developed many years ago and la well known. The tendency to elimination of this machine makes the problem one of little practical Interest now. In moat plants, dust from other equipment, such as spinning and twisting which are commonly In the same room, Is of greater importance than that from winding operations. 0 03852 Preliminary Dust Surrey for Aabeatoe Textile Institute, n June, I9U7 Wearing One plant baa a superior method of suppressing duet In wearing ty wet methods and dust count records indicate a coexists suppression of dust. It lnrolres a water spray head mounted above the varp at the rear of the harness with a mechanical screw arrangement for constant movement of the spray head transversely to the varp. They believe It to be mare effective tbn the system coinnon in several plants wherein the varp is passed over vetted rolls. It Is apparently not practical to reccamend 100 per cent vet weaving throughout the lnduatry. Moreover, ve are satisfied that It is practical to control dust In this operation by local exhaust, where dry weaving is consider ed laperatlvefor special properties of the cloth. One of the best exhaust arrangements Includes an exhaust opening directly under the varp at the rear of the harness frame with a slot exhaust opening carried by the lay beam, the latter connected to the stationary part of the exhaust system, either by flexible hose arrangement or by an all metal swivel Joint. Duct Work The actual arrangement of duct work and exhaust fan present no un usual problems where good practice in sheet metal fabrication la followed. Two points are of sufficient Importance to require emphasis. Special care should be exercised In the fabrication to avoid sharp projections on the inside that create points of lodgement for fibers. Secondly, It must be designed to pro vide adequate transporting velocities. Velocities below 2000 fjsa, in the experience of the industry, may permit settlement of material and gradual clogging. Therefore, allowing a margin of safety, the design should provide for velocities of 3000 fpm. D 03853 Preliminary Duet Surrey for Asbestos Textile Institute, June, I9U7 .lbs problem of dlstributicn of planned air flows to the different bxanohes of the systea Is of importance In the deslga of all dust exhaust systems. - The use of daapers In branches to adjust air flows Is avoided In the best systems. Their function In effecting balance between branches Is best attained In the original deeign. Desi* procedures to effect ob jective are available but will not be elaborated at this point. IXiat Collectors Vive plants in the survey employ the well-known burlap dust house for filtering air from various exhaust aysteas. Bis favored filtering area Is determined on the basis of one square foot for each air flow of 2 cfm. Most arrangements are such as to permit cleaning by whipping with a bamboo pole or a buggy whip by men who remain on the clean air side of the filter cloth. 3b one system, the men are required to enter the duet elde for clean ing purposes, and finaleleaning la carried cut cnee weekly with the use of a central station vacuum cleaner. Practices In different plants are variable as to frequency with which the burlap filter Is freed of Its dust load by vhlppln While these dust collectors work well, we ere not prepared to recom mend them to the exclusion of sens comaercla1 types of filters having automatic shakers, Several engineering elements enter Into the design of a duet collect or system, Involving principally a proper estimate of pressure drop in all ele monte of the system and especially that through the filter proper (back presavx If the pressure drop estimate In the filter la incorrect, the system will not operate properly. If the basic resistance of the filter, l.e., that ins*late ly after shaking the cloth, is subject to a constant increase over a period 0 03854 Preliminary Duet Survey for Asbestos Textile Institute, June, 19U7 of weeks, the eyatem operation vlll suffer. Apparently, scoe of the older eoBBoerelal flat hag type of collectors did exhibit that difficulty. Modifi cations in the design of such units have, however, been Incorporated In more recent models and those difficulties may have been eliminated. TVo plants employ ccnaerclal collectors of the flat bag or envelope type. Another plant uses a cloth tube conacrelal collector and also one whose filtering element Is of paper, which is replaced at Intervale of eevezal weeks, A study of operating details of these comaercial collectors Is Indicated In this study, Including considerations at original cost and operating cost. Recirculation Several plants return air fren the dust collectors to the workrocn tc conserve heat In the cold weather. Ve are not prepared at this point either to condone or to condemn this practice except In cases where there la obvious ly leakage of duet through the filter and consequent recontaaination at the air inside the plant. The practice is generally frowned upon where duets that are hazardous to health are being handled. Ve believe there are certain circumstances where the practice might be permissible provided adequate safe guards are Ineozporated In operating procedures. The large volumes of air Involved In duet control represent a tremendous problem as to heat loss and boiler capacity which cannot be passed over lightly. 0 03855 Preliminary Dust Surrey for Asbestos Textile Institute, June, 191*7 1 H MEDICAL P1CSEHT MEDICAL PAdLITIES ASP PRACTICES Srex7 plant ha connections with a local specialist In radiology vho is esgjlcyed for diagnostic work cn an Irregular basis. Cues hare their own x-ray machines used by the local specialist, but only cos has a wellestablished schedule of periodic medical examinations. Half of the plants hams no positive Information as to the incidence of asbestosls among their workers. The situation is these respects is in dicated in Thhle XX. TUBUS n . ppusmr practices amp f a c h it o s Aa to medical X-RAY EXAMDIATIOHS IR VARIOUS HARTS Plant A B C D E r a H i J Ascent X-ray*' Survey Made Yea Ro Yes Yes Ro Ro Ro Yes Ro Yes Periodic X-ray Examinations Made Ro Ro Ro Ro Ro Ro Ro Yes Ro Ro Rave Own X-ray Machine Yes Ro Ro Ro Ro Ro Ro Yes Ro Yes ^Within last few years, and results available to plant or Its nhrslclan D 03856 Preliminary IXist Surrey for Asbestos Textile Institute June, 1947 S3ID4MZD m c m E H C g OF A3BBST0SI3 The Incidence of aebeetoale among employsea of thoee plants where employees vere examined In recent years, shears a narked variation as Indicate ed by the following: Plant A has recorded cases disposed as aebestoel* to the extent of about 20 per cent, and In the past nine years has compensated, on the average, two eases per annua. Total textile eaployment about 400. Plant C co the basis of a recent systematic survey, estimates aebeetoale Incidence to be about three to four per cent. Plant D has results fren an lneooplete survey In which four eases were found among thoee volunteering for examination with a total textile em ployment of around 150, They have compensated one case In about 10 years. Three more are pending. Plant H with a textile employment of 300 finds five or six cases T'rnvOTy that the physician believes show early changes due to asbeetoe. Plant J has counted potential cases of asbestoels amounting In number to about 20 per cent, ccsparable with Plant A. The other plants have conducted no syeteaatic x-rey surreys of their own and have no information as to Incidence among their employees. None of these has had cases requiring compensation. Vhils we have no coexists data on history of employment and labor turnover In the several plants, it la apparent that there is, at least superflclaliy, a marked Inconsistency In this picture. Also, It Is clear that D 03857 Preliminary Dust Survey for Asbestos Textile Institute. 16 June, 19Vf a serloue lack of information prevails generally cn thle aspect of the problem The atoiy In North Carolina la vorth special mention. state Instituted 10 years ago, a system of periodic medical examinations for all Yorkers in dusty Industries and, hence, all asbestos textile Yorkers have been x-rayed and clinically examined for a longer period, on a periodic basis, than any other asbestos textile plant In this group. If the state examination, finds that vorkars should discontinue their employment because of rapidly developing asbestosIn they have* the authority to effect this change. They also see to It that vorkore vho should recolve vortaoaa's compensation due to dis abling aaboatosls are processed. So far as ve have bean able to ascertain neither event has occurred to any esployee of the two North Carolina asbestos plants In this group. These observations suggest that there may veil be a marked divergence In medical procedures, Interpretations, and attitudes respecting the diagnosis of asbeetoels. There Is a very urgent need for a concerted cooperative medical, effort to develop improved diagnostic procedures and uniformity of Interpre tation. D 03858 Preliminary Duat Survey for Aabeatos Textile Institute, 1 June, 19U7 IMPORTANCE OF HEKIODIC MEDICAL ZIAKDIATIOWS Coe at the most Important elements of a program of protecting health of workers In dusty occupations la the periodic nedlcal examination, lbs lack of scientific lnfonmtlon regarding all aspects of asbestosIs Is serious* Oils casnot be orereemphasized. Oie obrlous procedure to help overcome t M deficiency Is to erploy eve17 tool now available that will throw more light on the facts* The lsportance of the periodic medical x-ray examination can per haps best be ez^haelzed by stating that duat count Investigations cannot, In the present state of knowledge, give us assurance as to the extent of our suc cess In eliminating the hazard. Regular examinations serve to protect the worker by giving early in dication of health impairment due to dust, and permit Intelligent action to be taken to avoid further serious health deterioration. This Is particularly true If the detection Is early enough and there la no progression to lata stage asbestosls. More Important, far the long term, the accusulatlcn of factual In formation regarding the health status of exposed workers, statistically inter preted in relation to duetiness studies and to mechanical developments in dust control equipment, will eventually indicate when the battle of aebestosie con trol Is being won. This aspect of the problem la elaborated In the following seotlon* The Inventory provided by such a medical program la Just as important to Intelligent action In this problem, as material Inventories are to the proper conduct of business. D 0385? Pral.lalnfl.ry Dost Surrey for Asbeatoe Textile Institute. June, 19^7 The question as to vhether a pleat should purchase Its ovn x-ray equipment Is aa economic one Involving consideration of cost of local outside nodical and x-ray facilities and of loss of employee tins In travel, etc. Diagnostic Panel To further the objective of Improvement and uniformity in dlagnoatie procedures, a medical section of the program Is proposed In the form of a MEDICAL ASBES10SXS BABEL to be conpoeed at outstanding medical man In field, and of the physician desl&iated by each company as the one responsible for Its medical and diagnostic vork. The composition, aa to cutails medical personnel, of this penal vould be determined by Its objectives: the assembling of the beet possible medical brains and the mutual education In diagnostic procedures that cooes from exchangee of scientific experiences and Information. The panel vould meet, perhaps semi-annually, and consider the sig nificance of x-ray films end other clinical data brought to the group by each participating physician. Dr. C. Richard Valmer's services vould be available for the organ!ration and other details. D 03860 Preliminary Duat Surrey for Asbestos Textile Institute June, I9V7 STATISTICAL 3TOD3B8 OF MEDICAL SBCOKPS There are two Tory lnportant questions concerning the physiological nature of aebestoe that hare not yet been answered by any published lnvestlgation: 1, What is the expectation of aabeatoels In workers exposed acre than 15-20 years to low concentrations of aebestoe dnstf Among the 500-cdd workers who ecspoeed the subjects In the U.8. Public Health Service study, there were abnormally few who had been expoeed for sore than 15 years axA practically none over 20 years. These facts seriously affected the conclu sions that could be drawn. 2, Is there a progression to advanced asbestoels after exposure oi an individual has beon discontinued or has been reduced to very low levels, due to action of dust deposits from earlier exposure! This question la of very great Importance to intelligent medical supervision of workers In these plants. It Is virtually certain that statistical investigations of existing records would throw valuable light an these questions. None of the plants visited during this inquiry have sufficiently extensive and systematic records to provide aatlef&ctoxy answers to these questions, but the medical department of Metropolitan Life Insurance Company, under Sr. A. J. Lanza, have x-rays of a number of men obtained in the early 1930's which could provide the nucleus of some useful information, depending on hew many of the original group are available for re-x-ray. D 03861 ProliBinary Dust Survey for Asbesto Tortila Institute, Juno, 19^7 The soot outatending toro of infornaticn la In the recorda of the Division of Industrial Sjgiene of the Worth Carolina Department of Health vho, In accardance vith state law have x-rayed worker In thla, and other dusty industrie, almost annually for the past 10 yean. A study of these records would undoubtedly east much light on the question of progression. Through officials of the company members In Worth Carolina, we already have assurances of their full cooperation In any investigations, and although vs have not discussed the matter with then directly as to details, there Is every reason to suppose that the desired Information would be mads available to us for the purposes described. In addition, a general x-ray and medical survey of workers In one or two plants with a long history of high order of dust control would be of great value for this purpose. D 3862 Preliminary Dust Survey for Asbestos Textile Institute 2 June, ISkl HI - P H Y S I C A L siamcAncg of dust countb Correlation between development of asbestoels end sene pertinent meaeure of dtaetlneea, e.g., duat counts, can be developed by periodically ob serving and recording data on both aapeeta -- periodic medical exaalaatlana of exposed workers together with the periodically measured duat exposure of each. However, to be useful for preventive purposes, tbeseprocedures have to be extended into the past wherever data is availab.e ibis was the proced ure eiqployed In the studies of the U.S.Public Health Service In Hearth Carolina plants (Public Health Bulletin Ho. 2bl, 1938). The main value of dust counts in asbestos plants is to obtain data on dust concentrations that can be compared with that study, and thus lead to conclusions as to probability of development of asbestoels in the particular plant being studied. In that study, dustiness of different occupations was measured in the usual manner, and also the incidence of aabeetoeis by medical and x-ray examinetione of the men employed. A statistical ccxaparlaan of the two sets of data led the Investigators to the conclusion that new cases of asbeatoels would probably not occur if duat control measures were undertaken to ensure that no dust exposures exceeded five million particles per cubic foot (measured In the same manner). D 03843 Preliminary Duat Survey for Asbestos Tbrtlle Institute, 22 June, 19^7 APPRAISAL OF mtXXD BUST HAZARD Having reached a degree of duet control represented by the duat count U n i t of five Billion, It la then proper to ask: *Vhat degree of assurance la afforded by existing knowledge that asbestosla vlll not, in fact, develop In the future If dustineas la kept below that level?" If there are factors, at present unknown, that will indicate a need for still better dust control,vhat will that H a l t bet The lnfomatlon available does not pemlt conplete assurance that five Billion la thoroughly safe nor has* infocnatlon been developed peralttlag a better eetlaate of safe dus tineas. It la nevertheless of the greatest Importance either that auch assurances be sought or a new yardstick of accomplishment be found for ac curately measuring any remaining hazard In tbs dust t o m below five million for the elimination of future asbeetoeis depends upon the degree of control 'effected now. Measurement of Dustiness One basis of uncertainty as to applying present conventional dust counting techniques to the measurement of aebeetoe dust hatards below the five million level la summarized In the question -- are the fibers of asbestos the causative agent or the non-flbrous "cubical" particle# that look like those of other industrial duets? The non-flbrous particles In most textile operations ccsprlse 80-9? per cent of the total duat seen in dust counting. While It Is proven that asbestos dust Is the cause of aabestoels, there is bo certain Infonsatlca as to what shape or else of dust is the causative factor. The correlation tudis of the U.8.Public Health Service 0 03864 Preliminary Dust Survey for Aabeetoe Textile Institute. ?, June, 19^7 " employed conventional dust count techniques which, in effect, rel&ted inr.i<^nr of aahestoels to the number of ncn-flbrous particles of a size ranging from one to five or 10 microns. For illustration, suppose the causative dust element la seething different, e.g., fibers that are less than 50-60 microns long, and less 1.2 microns in diameter. lhe conventional dust count method would be satis factory only if there were a fairly constant ratio between the two types of dust; it would, in that case, provide an adequate, index. Preliminary 8tudiee on Qualities of Asbestos Dust With a view to eventual development of supplementary methods for measuring asbestos dust concentrations cn a weight basis, ve have conducted some preliminary studies directed to the colorimetric determination of total alliea In the minute quantities of asbestos dust obtained in a typical atmos pheric easels. This required development since it could provide a valuable tool for further investigation. Sub-microscopic particles and fibers. Another aspect of the dust examinetlcn problem cn which preliminary work has been done Involved studies with the electron microscope. Ve posed the two following questions: 1. Ordinary dust particles, one to three microns in diameter, com prise moet of the particles in the dust count. They look like ordinary in dustrial dust and ve refer to them as "cubical" as distinguished from "fibrous" particles. The question is: are these particles In fact non-flbrous or are they bundles of fibers! D 03865 Prolidnc.r7 Duat Survey for Asbestos Textile Institute, June, I9U7 . 2. 8ecoodly -- since the H a l t of resolution of the microscope lenses used In dust counting does not permit seeing particles very ouch ssaller than one micron, one any ask If there are many fibers of great length, but of such small vidth that they are Invisible? Sangdes of atmospheric dust vere obtained far examination by the electron microscope, by mounting the small specimen sHde used vltfa this Instrument, In the dust collecting zone of the electric precipitator. In order to eliminate very large fibers, the air being sampled vas caused to pass first through a glass spiral coated vlth adhesive on Its Interior. This subjected the dust particles to centrifugal force and the largest ones vould be.pre- clpltated out, much as they might be In the nasal passages of nan. Studies vlth other Industrial dusts employing this spiral Indicate that very rarely do cubical particles larger than three to five microns suc ceed in passing through the several turns of the spiral. In sasplee obtalnedvlth this apparatus In a card room having a good dust control, ve obtained pictures, sons of vhlch are reproduced in the attached Figure. They demonstrate first, that the cubical particles seen by a low power llght-microacope are in fact bundles of fiber roecabling a life- size handful at partially opened fibers. The picture further demonstrated that there are many fibers of con siderable length, some fully 50 microns, vhose other dimension le only a fraction of a micron; the fiber is therefore Invisible In the dust counting microscope. D 03866 ELECTRON PHOTOMICROGRAPHS OF AIR-BORNE ASBESTOS DOST - MAGNIFICATION 5500 X c? 03867 THIS CIRCLE 1 MICRON DIAMETER - 4) Preliminary Duet Surrey for Asbestos Textile Institute, 25 June, 19lf7 They also showed sene fibers a fsv microns In length vhoee diameter Is only 0,01-0,08 mlcrcne, although the commonest particles are bundles of fibers about 0 .1 micron In width. In addition to the light theee Obeerrarlcns throw on the submicroscope character of asbestos duet, they are cited to Indicate the other qualities that might be pertinent to evaluation of dust exposure, to supple ment the duet count technique now in use. 0 03866 Preliminary Duat Survey for Asbestos textile Institute Juno, 19U7 INHERENT DUSTDES3 OF STOCK In Investigations of the type being presently considered, a primry ala suet be to develop Improvements In dust control vlth the 0f vasts notion and expensive experimentation on a plant scale. At the stage of develqpaent of the Industry, causes of dust are very often not obvious. An examination of dust count records aade available to us, ccabined vith the fev tests ve performed ourselves, provide numerous Instances of variation, the cause of vhlch Is not apparent. Ve undertook recently to aeasure the amount of dust In the roving of different manufacturers by suspending a measured quantity of roving In alcohol, then a dust count in the same manner as vlth air sasples. Die result vould be expressed in millions of particles per yard of roving or per gram, etr. and vould be of great advantage In relating differences in dustlneee to the causative factor. Such a measurement technique vould be essential In apprais ing the actual value of oil. Ve do not have sufficient data on this effort on vhlch to dzav con clusions. There are difficulties to be overcome, and the solution depends on more laboratory experimentation. Another test method vhlch vould be of value le a standardized mech anical abuse of roving in a small vessel vhile tucking a stream of air vlth resulting duat as in the sampling for ordinary duat counts. A teat of this kind, in conjunction vlth the dustiness Index vould be of value In evaluating the oiling practice, or It might take the place entirely of the procedure previously outlined. 0 03869 Preliminary Duet Survey for Asbestos Tortile Institute, June, 1947 OUTLIHE OF RECCMMB3TIZD PROCEDURES FOR ASBESTOeiS ETVE3TIGATI0B3 X, ENSPCOggNO A. Djaaenlnation of Existing Information Provide factual informticn to Institute members vith least possible delay; prepare bulletins vith dealga sketches cn sane or all of the several subjects Additional field required Hated below, to be distributed singly observations in many cases. as ready. 1. Carding dust control; for various m k e s of machines 2. Dust In preparation, miscellaneous operations 3. Vet veavlng equipment 4. Exhaust for Dry veavlng 3. Exhaust for vindere. etc. 6, Design of duct work 7. Design of dust house B, Development of Rev Techniques for Dust Control In this category, the problems far which there are no present ansvere: like twisting, spinning, appraisal of operation, efficiency and cost of cooaarclal dust collectors, etc. 0 03870 Preliminary Dust Survey for Asbestos Textile Institute June, 19U7 II. MEDICAL A. Institution of Periodic Medical Brawl nations Ibis la urgently recommended to all ccnpanles. Medical advice as to organ!rations procedures vlll be given by the Foundation upon request. B. Organization of a Diagnostic Panel for Aabestoels Arranged by the Foundation's Medical Director and organized to aest in Pittsburgh at suitable intervals for scientific review of diagnostic problems, reading of x-ray filas, etc. Panel to consist of Individual canpany physician or nodical consultants together vlth other medical authorities to be determined. C. Statistical Study of Existing Medical Records Designed to find answers to important questions concerning medical and physical nature of asbestosis; especially concerned with records of State of North Carolina, Metropolitan life Insurance Company, etc. III. HCfSICAI TESTING -- (Further Dust Studies) Studies of physical and chemical characteristics of asbestos dust designed, in conjunction with medical studies, to provide more significant information concerning the nature of the dust exposure; to develop supplementary techniques for measuring remaining aabestoels hazard after reduction of dust to meet the present standard; to insure that effective control of dust has been attained. This la a step by step program aimed at the elimination of aabestoels cases from the plants of Asbestos Tbxtile Institute members. C- 03871