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FILE NAME: General Electric (GE) DATE: 1932 DOC#: GE021 DOCUMENT DESCRIPTION: Transactions of the National Safety Council 1932 TRANSACTIONS National Safety Council Incorporated TWENTY-FIRST ANNUAL SAFETY CONGRESS Washington, D. C. October 3 to October 7, 1932 The Wardman Park and Shoreham Hotels Copyright. 1933, Platio.icil Safety Coitm :7. Inc. )! ' - -. CONTENTS PAGE Council Officers and Directors.............................................................................................. 3 Council Purposes and P olicies.............................................................................................. 7 General Sessions-- Annual M eeting of M em bers....................................................................................... 9 Annual Banquet.................................................................................................................... 21 Advanced Safety E ngineering....................................................................................... 23 General Round Table......................................................................................................... 33 Fire Prevention.................................................................................................................... 39 ^ Industrial H ealth Section................................................................................................ 45 ' Industrial Nursing Section.............................................................................................. 79 Safety in Forcmanship by the Conference M ethod........................................... 83 Accident Prevention Equipment Manufacturers' Section....................................... 107 Aeronautical Section.................................................................................................................. I ll A. S. S. E .--Engineering Section........................................................................................ 119 Autom otive and Machine Shop Section.......................................................................... 131 Cement Section ........................................................................................................................... 141 Chemical S e c tio n ......................................................................................................................... 157 Construction Section ................................................................................................................ 177 Delivery, Taxicab and Bus Section................................................................................... 191 Electric Railway Section.......................................................................................................... 201 Food Section .............................................................................................................................. 217 Marine Sc-ction ........................................................................................................................... 233 Meal Packing, Tanning and Leather Industries Section......................................... 251 Metals Section ............................................................................................................................. 263 M ining S e c tio n ............................................................................................................................. 277 Paper and Pulp Section............................................................................................................ 309 Petroleum Section .................................................................................................................... 327 Power Press Section.................................................................................................................. 347 Public Utilities Section............................................................................................................. 357 Quarry Section........................................................................................................... 379 Refrigeration Section ..................................................................................................................387 Rubber Section ........................................................................................................................... 395 Safety Section, A R A --Steam Railroad Section, N S C ............................................. 405 Textile Section ............................................................................................................................ 435 W oodworking and Lumber M anufacturing Section.................................................. 447 Index................................................................................................................................................... 455 * Although the National Safety Council endeavors to eliminate from discussion at its conventions matters which are not pertinent to its purposes or which are contrary to its policies, the Council accepts no responsibility for the views expressed either in the papers presented or in the discussions thereon. * ^ N O T E : The sessions of the Street and Highway Traffic Section, the' Child Education Section, and the Home Safety session arc published in a separate small volume of these Transactions, available on request. National Inci 20 North Wac HONORAI A ssociation or Ikon' and R obert 1 A rthur J. I. Banasii, President. OFFICER R(.meter I. Gatlin, Vice-President for Pul J. E. Culliney, Vice-President for Engi GH.oTw.arHdeBll. mFuotniid,aV, iVceic-Pe-rPersiedseidnetnftorlorBu1 J. E. Long, Vice-President for the Divis George H. W arff.l, Vice-President for It I.ir. C. H. W atson, Vice-President for I'. WA.ilWl .CWoopheirt,nTerye,aVsuirceer-.President for Edi W. II, Cameron, Managing Director and C. B. A.u.e..l..,....Pj^aisetiyPrDesiivdiesniot.n, Milwa J. I. Banash, Consulting Engineer. CE.rnWes.tBWer.gBqup.ciskt,, UPnaisttedPrSetsaitdeesntR. ubber ( C. B. Boulf.t, Public Utilities Section. RWo.iikIrf.t CWa.meCraomnp,beNlalt,ioPnaaslt SParfeestyideCnot.unci RFroabenrkt II.I.CCaotoliann,, AMeatnraineLiSfeectIinosnu.rance C W ii.t. Cnoi i.r, Stevens Hotel. --J. E. Cm unt.y, Bethlehem Steel Compan; ELedwwiasrdA.DDarn.Bat,.oBiso,stPoanstEPlerveastieddentR. ailway. .Marcus A. Dow, I 'ast President. HP.oIwIa. rGdi.Bat. fFelotnedra, ,YBourkrroCuoguhnstyWSeallfceotymeCo& I lit. H T hoGmuailsdeWrt. ,GTohselinPgu,llSmuapneriCnotemnpdaennyt. o G. aTr r. y H e l l m u t i i , Chicago, North Shore & W aiter G. King, Past President. Franklin M. Kreml, Evanston Safety Cot TFrhaonmkasJ.EL. aLnigaihitafono, tF, oMrtinPinitgt MSeacltlieoanb.le I John E. Long, The Delaware & Hudson E 4 :irn!y-firs! Concjress--National Safety Council \HV. . \ VW. . L M oarcmku, rD, eClal ewvaerlaen d S aSfeatfye t y C oCuonuc nilc. i l . Artman T Morey, Past Presi'lent. Lkw R. Palmer, T ail President. CJ.. JE. .P 1F.2fA.tKti,rPovarp.e.rP5a;stPuPlpresSiedcetniot.n. I t. EC.oeS.aHniemnmrjy, GAe.nRerfa.x!ixEglfe.crt,riPcasCt oPmrpeasnidye.nt. CErhnaersltesC1. !.S Simcoontto,rP, aNsetwPrHesaivdeennt.Safety Council. C. \V. S mith, Standard Oil Company (Indiana). 1R1.. TS.. SSmoj.irt.NhS,TAF.SKS, EA--ccEidnegnitnePerreinvgenStieocntioEnq. uipim-nt Manufacturers- Section. John II. T aylor, Birmingham Safety Council. A rthur M. T ouf.. Consulting Marine Engineer. CG.eoIr*g. eT oIIi..mWana,rPitals,t UPnrieosnidePnat.cific Railroad Company. Dr. Cassius H. W atson, Ameriean Telephone & Telegraph Company. WA.. WL.. WWhhiitten,eJyr,.,NCaetimonenatl SPencirtieoanu. of Casualty 8: Surety Underwriters. I)r. C.-E. A. W inslow, Vale Medical School. Arthur II. Young, Past President. DIRECTORS (1932-1933) AMu. gSu.stAucskeLr.mAabnb,oJtrt.,, SLte.hiLgohuiVs aSllaefyetySafCeotyunCciol.uncil. W si. F. A kdern, Safety Division. Milwaukee Association of Commerce. J1o. hI.nBRananakshs,, MCoandsiusoltninCg oEunngtyineSearf.ety Council. John W . B arton, Safety Department. Nashville Chamber of Commerce. Ernest W. Reck. United Slates Rnhhcr Company. W. A. B ennett, Worcester Safety ouncil. L. G. Bentley, Richmond Safety Council. CD.avWis. SR.r.UiiCk.vneurif,tL, ibWeretsyterMnutEulaelctIrnicsurCaonmcepaCnoym. pany. E. F. R lank, Jones & Laugldin Steel Corporation. WC.. RR. . RRoouviu.e,t,JrP.,ubAlmicerUictialnitiePsetrSoelcetuiomn. Institute. TR.11OAM. ABSrWya.ntB,rSewafeerty, HDrizvcisUioonu, SSayfreatycuCseouCnhcailm. hcr of Commerce. RGra.ol.phA.CC. B ush , E,leKcntroicxvRillaeilwSaafyetySecCtioounn.cil. \V. II. C \ amlf.drwo e x l. lN a t i o n a l Safety Council. Robert I, Cati.in , Aetna Life Insurance Company. WFrialnlkCoHo.peCr,ogSatenv, enMsarHinoetelS. ection. J. E. Cui.linf.y, Bethlehem Steel Company. EF\nwAA.RDn aDvaidnsao,nB, oCstoonnsuEltlienvgatEedngRinaeielwr.ay. Clifford D avis, Street S: Highway Traffic Section. LC.haWrl. eDs aDw.i.eDya, wRseofrni,geGrraatinodn RSaepctidiosn.Safety Council. J).al y E. AD. eDckeeRrl,oMis.asCoonnsCuilttyingSaEfentgyinCeeoruncil. 1 I I1 j * Officers j D r:..ikLso uLi i s DI o. uDciu ss, bli nT, h Me ePthroilpaodleiltpahni aL DErr.i.dCi.hraicrlWes. HE.asEtaomn,ksB, laTcekxsttiolencSeVcatiil Hakvf.y E llkrii, Armour & Company. Donald A. Finkreixer. Toledo Snfct TRahlopmhasT.FiFtizsghefr.arl, dE. aWsthesatyerSnafreetynnCsyo J('I.oIwfa. mGilaRt. feFlotnedra, ,YBourrkroCuoguhnstyWScallfccot Ernest I*. Goodrich, Consulting Eng'i Dr. 'J'homas W. Gosling. Child Edu< tVnm M. Graves, Quarry Section. ! ! I l 11\Kitv Guii.iif.icr. The Pullman Comp; Isaiah II m e. The Alehisnii, Topeka 8 D. T. H arrington, U. S. Rureau of M E. M. IIkixfki.man. Safety Rureau. J) <1. T. 111 i.i.mutii. Chieago. North Slim I.. HIGHTOWER. Petroleum Section. ('has. If. H ill. New York Central I.ii JIIc.imiiixryPDri.ceImJmaeclk,soDne,paNrtemwenYtoorfk l.Eadlimis RDoalnaandE.JoJnoense,s,WMooadnwufoarcktuinrgersanAdssLoucii Ira V. Kepnf.r. Pennsylvania Salt Ml I-'ranklin M. Kkf.ml, Evanston Safety TFrhaonmkasJ.IfL. aLxigaihitafnoo, tF, oMrtinPiintgt MScacltlicoael JK.. EM. .LLointgt,leT.hNe eDwelYaworakreDfetpaHrutmdseonnt II. W. Loumoic. Cleveland Safety Com WII.. TW. .MMaratcikn., DFieslkawRanrhehScrafCetoymCpaonuyn.ci F". W. Matson, Minnesota Safety Omni Paxton Mendelssohn, Detroit. Henry J.. Minf.ur, Food Section. W. S. Moki.lkuing. Fort Wayne Safety V uiian L. M oi.f.u, Dayton Safety Conn. K. R. Morlky, Industrial Accident I'rcv WMimll.eCri. MMccCCuunltio.acmk., EHliazravbaertdh SUanfievleyrs( I'. H. MfK ennf.y. Illinois Steel Comp A. D. McW horter, Safety Division, Mi CJoohln. *RAe.n P. N ic Oartel, klin, Chattanooga Sa Carnegie Steel Comp 'CI'iloiorso.k EC. . OAw. eOnp, pE. mThpeloyDeeetsr'oiPtuhEldieiasotinoi LJoehwn RC. . PPaalrmkeerr,. EBqrouoitkalbylne IS.aiffcetyAsCsuorm; CB.haEi.naPredttPirloantet,, ALmouerisicvailnle MSuatfueatyl TC.iaoF1. J. J. P lzaK. Paper & Pulp Section. C11h. aRr.. PEo. tRtefr.d.fBehanlt,imPorroevidSeanfectey SCaofuetnycilC. I.t ,-i>l. H enry Renin- er. Lehigh 1 6 Twenty-first Congress-- Xotionol Safety Council C. L. R ick, Chicago Safety Council.' D r. A. D. Ristf.kn, The Travelers Insurance Company. John Roach, Chemical Section. Chas. J. Ron, Newark Safety Council. Toni.vs Roth, Rochester Safety Council. John Russf.ll, Jr.. Construction Section. G. E. Sanford. General Electric Company. H enry G. Schaffnkr, Eric Safely Council. Otto Schenk, Wheeling Safety Council. Rorf.rt I.. Schmitt, Metals Section. Charles. 15. Scott. Bureau of Safety. Gen. John H. S hekourne. Massachusetts Safety Council. D r. L. A. S houdy. Bethlehem Steel Company. E rnest L. Simonus, New Haven Safety Council. Gforce P, Singer, Reading-Berks County Saiety Council. O liver T. S kkllkt, Safety Division, St. Paul Association. Charles F. S mith, Rubber Section. C. W. S mith, Standard Oil Company (Indiana!. E. J. S mith. Power Press Section. H. S. S mith. ASSE--Engineering Section. R. T. Sclf.nsten, Accident Prevention Equipment Manufacturers' Section. E. C. Spring. Lansdaie, Montgomery Co., Pa. George I\. Stephens, The Saiety Bureau. Buffalo Chamber of Commerce. Etiif.lrf.rt S tewart, Washington. D. C. Carl Storck, Automotive & Machine S'.top Section. I. rcius S. Storks, United Railways St Electric Co. -A lfred H. S wayne, General Motors Corporation. John H. T aylor, Birmingham Saiety Councii. H enry D. T f.fft, Meat Packing. Tanning & Leather Industries Section. Norman F. T itus, Hudson County Safety Council. Arthur M. T odf.. Consulting Marine Engineer. W. D. T urreville, San Antonio Saiety Councii. W illiam F. V eecii, Rahway Safety Council. V incent W akefield. Kansas City Saiety Council. George H. W arvel, Union Pacific Railroad Company. Dr. Cassius H. W atson, American Telephone & Telegraph Company. H arry M. W f.erer, Illinois Bell Telephone Company. C arroll V. W ells, Delivery, Taxicab c Bus Section. Alrert C. W hite, Jr., Springfield Saiety Council. WS. . EL.. WWhhiittien,gJ.r.L, ibCeermtyenMt SuteucatilonI.nsurance Company. AW.. III.I.WWhiintannesy,, UNnatioionnaCl aBrbuirdeeau&ofCaCrabsounalCtyorCpcoSrautrioetny. Underwriters. CD.r.TC. .W-E.inAeg. aWr. iDnseltroowit, IYnadluestrMiaeldiScaalfetSychCoooul.ncil. J. M. W oltz, Youngstown Sheet & Tube Company. 50 Twenty-first Congress--National Safety Council a proper staff, ami not by some enthusiastic person who has not been trained for the work. Why not use more registered nurses in the smaller plants? The registered nurse is much better qualified to interpret a physician's plan of medical service than any lay attendant. Much depends upon the physical condition of the employees. I am of the opinion that the physician, by reason of his professional attainments, is best qualified to handle some of the problem cases among employees. Mental symptoms, brought about by worry over home affairs, quite often produce accidents. In many cases the fear and worry of sickness in the family can be greatly allayed by a talk with the doctor or the nurse. Many of these cases have come under my personal observation. It should also be absolutely the part of the physician to say when a man shall return to his regular employment after injury, and this decision should not be in oflruernecceodrdi.n Tthheesseligchotnetsetstbsyarites pproospseibrleanadffehcatveonbraonuygh"tnoa-blooustt toimutestaancdciidnegntr"escuoltnsteisnt the reduction of lost-time frequency figures. However, there have been cases of injured employees being urged unduly to return to some form of work meroly to prevent the marking up of a lost-time accident. Nothing should be allowed to inter fere with the employee's welfare. The physician has every motive to return the employee to his regular work as promptly as possible, but his higher duty is to cemonpsleoryveer. both the physical and economic welfare of the employee as well as the coT-ohpeersaatefetaynddirseecetkortohabs rninegedaobfoutthea mmeduitcuaall sfeerevliicneg, aanmdonthge thtwe oemshpoluolydeees.arnBesottlhy departments are striving by all possible means to prevent economic waste chargeable to the disabilities and hazards of industry. TUESDAY AFTERNOON SESSION October 4, 1932 The delegates first attended an informal luncheon, and then gathered for the after noon meeting in a Joint Session with the Metals Section. This session was devoted to a symposium on the dust problem in industry. Chairman Greenburg immediately introduced the first speaker. _ - - 1- ' - ' The Effects of Inhaled Mineral Dusts By LEROY U. GARDNER Director, Saranac Laboratory for the Study of Tuberculosis, Saranac Lake, N. Y. As long as men have worked in stone it has been appreciated that an unusually large proportion of them suffer from disease of the lungs. It was natural to assume that such disease would be caused by the dust generated, and this belief was strength ened by the discovery of black, grey or red pigments in- the lungs, sometimes accom panied by the formation of scar tissue. The term, pneumonokoniosis was introduced to describe the lung pigmented in this manner. With further observation pathologists attempted to classify various forms of pneumonokoniosis on a basis of the type of dust inhaled and such names as anthracosis, siderosis, chacicosis and even byssinosis and tobaccosis made their appear ance. It was recognized that some forms of the disease were attended by severe symptoms and result in death but there was no correlation between the clinical and pathological pictures and the causative dust. Finally, statistical study demonstrated that of all kinds of industrial dusts silica generally produced a definite type of disease with a characteristic pathological lesion and complex of symptoms. 1 Industrial Health Section 51 I a trained tor Today the clinical entity known as silicosis is one form of pneumonokoniosis which is quite clearly defined. Moreover, within the last three or iour years asbestos Just 1l .'he registered J service than has also been shown to produce another specific type of reaction attended by symp toms differing in sonic respects from silicosis. at the opinion iified to handle ' The other forms of pneumonokoniosis still lack complete definition. The wide spread use of radiography has brought together a mass of descriptive data from indi ught about by tlie fear and ; ! viduals exposed to many kinds of occupational dusts but these findings have not yet been correlated with pathological anatomy, chemical studies of the tissues and de i the doctor or .tion. | tailed analyses of industrial atmospheres. There is a tendency to assume that many of these pulmonary changes are due to the action of silica perhaps modified by the r. a man shall ild not be in- j chemical components of the dust. We shall only be in a position to speak with assur ance about them when the pure types of dust and their various combinations have -ident" contest ;mg results in i been studied in human beings or in experimental animals. For the sake of clarity no mention lias been made of the infections which so fre been cases of rk merely to j quently complicate some forms of pneumonokoniosis. In the prcbacteriological era of medicine the use of such terms as "grinders' consumption" and "miners' phthisis" ` wed to interto return the I reflects the popular association of pneumonokoniosis with tuberculosis. The names were justified both by clinical and pathological observation for it has been subse .r duty is to . well as the j 1 quently shown that, in silicosis at least, a super-imposed tuberculosis may cause death in perhaps 75 per cent of the cases. Some observers even go so far as to state that silicosis itself docs not develop unless the lungs are previously damaged by a latent ':.>uld earnestly .loyees. Both ! j tpurboderuccueldouisn itnhfeecetixopne.rimTehnistalisanpirmobaalbblyy atnheeixnahgagleartiaotniono,f fsoilricatypwicitahl osuitlicinosfeiscticoann. be The role of asbestos dust as an excitant of tuberculous infection is not as clear i 1 iste chargeable ! cut as that of pure silica. While there are numerous reports oi death in asbestosis III due to a terminal tuberculosis, nevertheless surveys of living workers have failed to fh demonstrate any excess of such' infection. Simple anlhracosis is said to prevent the . r> i progression of tuberculous infection. Statistics from coal mining districts do show a tuberculosis rate much lower than that `'normal'' for the ace group. As yet corrobo rated experimental proof of protective action of coal against tuberculous infection . [or the attcr- is lacking. Not only the tubercle bacillus but other bacteria seem to develop with special I n was devoted rg immediately facility in the tissues previously damaged by silica. For example, the pneumonia rate among silicotic native laborers of South Africa is many times that in noil-silicotic natives living under similar conditions. In coal miners, likewise, pneumonia is a common and often fatal complication. -1 What has been said of the effects of inhaled inorganic dusts would indicate that the reaction of the tissues is not merely a response to mechanical irritation hv par ticulate matter. Today it is generally accepted that the injury is chemical in nature .! i:. and that only certain of the common types of industrial dusts assess properties ac Lake, N. Y. at an unusually * capable of exciting reaction. In the cases of silica and the silicate of magnesium or asbestos the slightly alkaline body tluids probably effect a slow solution of the dust . particles liberating silica in colloidal form. This substance irritates the connective l . 'l: ..:urwaalstostraesnsugmthe- j tissue cells which respond by multiplying. The result is an overgrowth of the sup porting framework elements at the expense of the more delicate cells specialized for metimes accom- | specific functions. gmented in this j For these two types of has been carefully worked dust out. the In cshialircaocstiesr and the form of essential the pathological changes tissue change consists of various forms - h names as an- nodules of connective tissue which develop first in the lympoid tissues situated in the drainage apparatus *of the lungs. These nodules interfere with the physiological le their appearnded by severe ^ removal of foreign bodies and subsequently inhaled particles accumulate in the framework of the lung itself. Such reaction gradually decreases the normal elasticity i! . the clinical and !y demonstrated ! of the organ and encroaches upon its functional elements. As a result the cardinal symptom of the disease, dyspnoea or shortness of breath develops. Because of the :type of disease excessive amounts of scar tissue formed in the lungs the right side of the heart I t1: 5- / fitly-first Lont/rcss--Wilionnl Sofcty Council encounters increasing difficulty in forcing Idood into the organs. In an attempt to compensate the overworked heart muscle becomes thicker and heavier and unless ifnrofemctitohnisinctaeursvee.nes the time eventually arrives when the heart fails and death occurs The reasons for the prevalence of infection in the silicotic lung are not altogether clear. It is obvious that when the drainage system is so obstructed by nodules of scar tissue that more dust particles can only be removed with difficulty, the same must he true of bacteria which may be inbalcd. As a consequence they remain in the lung and set up progressive infections. Tint this is not the whole story. The silicotic tissue apparently offers a peculiarly favorable soil for the continued multiplication of tubercle bacilli and perhaps other bacteria. Experiment has shown that even at tenuated organisms of this type will produce rapidly fatal tuberculosis in a silicotic guinea pig. Furthermore, inhaled silica dust will cause a pre-existing latent tuber culous focus, harboring a few attenuated bacilli, to become progressive and spread. The cause of this effect upon tuberculous infection has not yet been ascertained but probably it is in some way associated with the death of tissue caused by the toxic silica. Associated with this factor is an increased activity of the phagocytes which arc stimulated by the irritating silica so that these cells tend to migrate rapidly and carArsybctuslbnefrcdleustb,acpielrlihainptsobpecraevuisoeuoslfy itusnifnibvroolvuesdstprourcttiuornes, of is the not lung. transported very far within the lung. It tends to lodge along the walls of the finer tubes and little of it is i removed by the lymphatic drainage system. Tissue reaction, probably initiated by the solution oi the fibers, occurs in their immediate vicinity. As in the case of silica this reaction consists of an overgrowth of the connective tissues which is later transformed into leather-like scars. Aluminum oxide will serve admirably as an example of a nnu-siliceous dust whose particles are a? hard and sharp as those of crystalline silica. When a measured quantity of such particles. 1 to 3 miera in diameter, arc injected into the car vein of a rabbit the majority of them come to rest in its liver and spleen. There they remain, apparently harmless, collected in large phagocytic ceils and producing no reaction of the connective tissues for at least two years. Injection of the same quantity of the same sized quartz particles excites the formation of so much scar tissue that the '... I 1 functional elements are almost completely destroyed and tlie organs are reduced to nodular masses of leather-like consistence. Carborundum, the carbide of silicon, when inhaled by guinea pigs for periods as long as four years, likewise fails to excite significant overgrowth of the connective tissues. It produces only a low grade inflammatory change with no nodules. Instances such as those cited constitute the basis for believing that, the cellular response to dust particles is not due to their hardness and sharpness but to chemical substances liberated by the action of the tissues upon them. The case for solubility has not been proven directly, for the detection of soluble silica in the tissues offers technical difficulties which today are unsurmountable. Nevertheless this substance is known to be a cell poison and in weak concentrations it will provoke an overgrowth of the connective tissues. Mention should be made of the effect oi inhaled coal dust. Most city dwellers cborneasitdheerainblseuaffriecaiesntofquthaenitritliuesngosf. thDisepmoasittesrioafl dgrueryingorabnlaacvkerdaugset lwifiel-ltibmeefotuonpdigamloenngt the course of the lymphatic drainage system but this pigmentation is associated with little or no new growth of connective tissue. The coal miner's lung is much blacker :i but in most instances it afso develops no deforming scars. When such reaction does occur analysis usually reveals appreciable amounts of silica in the lungs. Tbe presence of excessive quantities of carbon dust apparently influences the localization of mod erate amounts of silica so that the latter is not deposited in nodules as in pure silicosis but in streaks along lymph vessels as pure coal would localize. Coal miners' fibrosis, due to relatively small amounts of silica, is therefore dif- H . :< ! Pfi ww>mum wwunmwmMweptw .n id i' In an attempt to I heavier and unless 1 .its and death occurs are not altogether i ucted by nodules oi . i ilty, the same must they remain in the -torv. The silicotic ..lied multiplication diown that even at- ' .ulosis in a silicotic ; .stint? latent tuber- -essive and spread. : ' ren ascertained hut , caused by the toxic : he phagocytes which j migrate rapidly and ! mg. .ransported very far , ' cs and little of it is ably initiated by the hie< claatseerotfrasnilsifcoarmtheids ; -Wlicheeonus adumsteawsuhroesde :Tohtehree ctahreyverinemoafina. ing no reaction of me quantity of the -car tissue that the :ans are reduced to pigs for periods as -h of the connective j :gio tnhoadtutlehse. cellutar | .esrsasheutfotro scahheimhiilcitavl , in the tissues offers t '. -s this substance is ' nice an overgrowth i Most city dwellers j '.iie-time to pigment j > will be found along j i is associated with * r-i.nsgucihs mreuacchtiobnladckoecrs lj 'uiigs. The presence ! ' calization of mod- j ' > as in pure silicosis ! a. is therefore dif Industrial / (calili Section ferent from that of the pure quartz worker. When the amount of inhaled silica is excessive, the effect of the coal is negligible and the reaction approximates that in [Hire silicosis. There is said to be more reaction to hard coal than to the bituminous variety hut there is evidence to suggest that this is due to the greater amount of siliceous rock which must be worked in mining anthracite coal. Finally, consider the silicosis of granite cutters. This develops somewhat more slowly than that of the pure quartz miner and it has been maintained that this is due to the relatively small amount of uncoinhincd silica in granite (25 to 40 per cent). Rut it is believed that other components of the glomerate granite may neutralize or at least inhibit the effects of the silica so that only after prolonged exposures to high concentrations does significant reaction occur. While typical silicotic nodules develop in guinea pigs inhaling pure quartz for a year, not even the earliest sug gestion of nodules have appeared in the lungs oi animals inhaling comparable concen trations of granite (40 per cent silica) for four years. This brief discussion of some of the problems involved in pneiunonokoniosis draws attention to the limitations of our present knowledge. It indicates that the reaction to an inhaled dust is determined by the chemical and probably physical composition of that dust. It emphasizes the need to further study of different types of dust both in the pure state and in measured combinations. The ultimate aim of such a study should be the neutralization of the toxic action of such dangerous substances as silica. The Dust Content of the Atmosphere in Var-io_usDu's-Vtryvz!Industries By J. J. B L O O M F IE L D Sanitary Engineer, United States Public Health Service, Washington, D. C. The speaker said in part: The properties of a given dust which determine its capacity to produce pulmonary' pathology are, the nature of the dust, that is, its chemical and mihernlogical composition, its particle size, and finally the quantity of the dust dispersgd in the atmosphere. One of the outstanding results of the last 20 years of research in the field of dust inhalation is the demonstration of the fact that,, in general, the degree of health hazards associated with the inhalation of any dust, all other factors re maining' constant, is dependent upon the nuncralogical composition of the dust. For example, it is now well established that the inhalation oi certain types oi dust, such as granite dust, will in time produce fibrosis oi the lungs, at times associated with tuberculosis. In other cases exposure to dust may result in the production oi much less fibrosis without notable tendency toward subsequent tuberculosis; this is true of cement dust. And finally, there arc certain types of dust, as typified by marble dust, which in the quantities and lengths of exposure so far observed produce little lung fibrosis. In general, it has been iutmd that those dusts which are high in qreuaadritlzy. content are the ones which produce a disabling fibrosis of the lungs most So far as the size of the dust particle is concerned, it is apparent that in order for any given dust to produce injury to the lungs, it mbst gain access to the pItariesnckhnyomwan othf atthenoltunagll, otfhethseitepawrthicelrees tohfe inhhaarlmedfulduesftfegcatsinoaf ctcheess dourstarteakreetpalianceed. sbiyzethoef thhuemdanustlupnagr.ticIlens tphriessecnotnninecttihoen initduisstroiafl imatpmoorstpanhceere.to have regard to the With reference to the quantity of dust present in the air of a workroom it is gaprepaatreerntquthaanttitwyhienn athgeivdeunstpecroinodcenotfrattiimone tihsanhighhe twhiell ewxphoesnedthpeerdsuosnt cwoinllceinnthraalteiona of the atmosphere is relatively low, and since the rate of production of the fibrosis 54 Twenty-first Congress--Xational Safety Council is partially dependent upon the rate in which the dust is inhaled, this latter item plays an important role in predicting the relative danger of different environments. pHheenrceeisthoebvnieoeuds. for the evaluation of the quantity of dust in the industrial atmos Research on the problem of industrial dust inhalation has indicated that so far as their fibrosis producing qualities arc concerned, dusts may be divided into three groups: f l) those composed completely oi combined silica, that is silicates, such as pure asbestos: (2) those containing free silica in the crystalline form known as quartz, (granite contains approximately 25 per cent of quartz) : and (3) dust con taining free silica in a non-crystalline form such as diatomaceous earth. In general, it has been found that the harmfulness of a quartz containing dust is in direct proportion to its quartz content. For this reason, in attempting to evaluate the harmfulness of a dust, it is oi the utmost importance to ascertain its exact min er.iogic.nl composition. It has been our experience thaf to determine accurately the exact mincralogical composition of a dust one should resort to a combined chemical and petrographic analysis. By no other method have we found it possible to determine the amount r.f quartz present in a given sample. In certain instances, such as when one is dealing with a mixture of quartz and pure potash feldspar, it is possible to deter mine the amount of quartz present in such dust merely by a chemical analysis. However, most dusts which come into question are mixtures of quartz and silicates. Take granite for example. The average granite is made up chiefly of three min erals in about the following proportions: feldspar 60 per cent, quartz 30 per cent, and mica 15 per cent. Chemical analysis shows that this average granite contains "A per cent of silica. Oi this 70 per cent. 30 per cent is present as quartz (free silica) and the other 40 per cent is present as combined silica, in chemical com bination with the other minerals that make up granite: it is possible to determine these proportions only with the aid oi the petrographic microscope. We find in practice that samples of dust settled out of the asmosjihcrc at the breathing level of the worker serve admirably for both chemical and mincralogical determinations. Table 1 presents the quartz content oi dusts obtained in various industries which we have studied. I TABLE 1 Percentage of Quartz Present in Various Industrial Dusts Kind of Dust Percentage of Quartz Rock drilling dust ( bituminous coal m ine)......................... Granite cutting dust............................................................................. RBroacsks dfroiullnindgrydudsutst(.a..n...t.h...r..a..c..i.t.e.....c..o..a..l....m....i.n...e..)............................................................ DSluastte fmroilml druaswt m(Vilelrsminonctemreednstlaptlea)n..t........................................................................................... Silverware polishing dust..................................................................... Anthtacile coal dust.............................................................................. Bituminous coal dust............................................................................. Cement dust ........................................................................................... Slate mill dust (Vermont greenslate)................................... TMaalrcblme ilclutdtiunsgt..d...u..s..t..................................................................................................................................................... 54.0 3c.2 31.0 19.0 63..50 1.7 1.5 1.2 1.0 trace nonenone It is evident from this table that rock drilling occupations in the coal mining industry and certain occupations in the granite cutting industry and in brass foun- ;< dries would be in the hazardous class as judged by the proportions of quartz in - the atmospheric dust.- i n k rlo; tr ot m ac in mill:! ph s!i| In mtioe me. cmuar; / atm the F qua: size reqt will the olisc indu the . and This sounceh-! mininaal bySotl dimei size 1 who silicoi and a majoi The : in coi tides mills, by N; In I nifican or int .. il Industrial Health Section 55 I this latter item ent environments, 1 It has been demonstrated that particles of dust of a size greater than 10 to 12 microns in longest dimension arc very seldom found in the lungs. This absence of industrial atmos- | larger particles is partly due to the fact that the numbers of such particles ed that so far as -iivided into three greater than ten microns in size present in industrial air is. as compared with the lower sizes, comparatively small; furthermore, these larger particles do not pene trate to the terminal portions of the respiratory tract. Hence we need only concern is silicates, such | form known as ... omuernsseilovne.s with those dust particles that are less than ten microns in longest di :id (3) dust conirth. In general, : In order to ascertain whether or not an industrial dust is capable of gaining access to the lungs, it is necessary to know something of the size of the particles lust is in direct _ to evaluate the ; in the dust under consideration. In practice the samples for particle size studies may be obtained by the use of the Owens jet dust counter. The advantage of this in its exact min- j instrument over other devices is that the Owens apparatus projects the atmos I act mineralgica! i and petrographic pheric dust in unaltered condition directly on a microscope cover-slip. This coverslip may then be properly mounted and examined by any one of several methods. In another method a microphotograph of the dust is mane at a high magnifica nine the amount i as when one is j tion: the particles revealed on an enlarged print or screen may be measured by means of a millimeter scale. No matter which method one uses for particle-size nssible to deter- _ iicmical analysis. f measurements the results may be treated in the customary manner. The-particles may be grouped in classes according to size, from which a percentage distribution :irtz and silicates. ily of three min- !' ; curve is easily obtained. As pointed out earlier, a knowledge of the quantity of dust dispersed in the ::irtz 30 per cent. granite contains j atmosphere is very important, since with any given dust the rate ot production of the injury will be dependent upon the total quantity inhaled. as quartz (free chemical comble to determine ! < From the practical hygienic viewpoint, the particle count is at present the best quantitative index of the degree of atmospheric pollution. The decision as to the size range of the particles which should be included in the dust count is a question :.nodosmphienreeraalotgitchael . requiring careful consideration. Obviously the size ot the smallest visible particle will depend on the magnification and type of illumination used in the microscope, ' wined in various ; the refractive properties of the dust and to some extent on the visual acuity of the observer. Wc must bear in mind that our chief interest in this problem is in the industrial hygienic aspect. Primarily wc are interested in differentiating between ' the dust content in the ordinary normal atmospheres, not yet known to be harmiul, Dusts and certain industrial dusts which are known to be associated with lung damage. This difference is sharply marked so far as the dust particles between approximately ,b -ccntage of Quartz one-half and ten microns in diameter are concerned; but the difference between such normal and abnormal air is masked and lost when we include in our deter 3i lSo.2 mination tiie particles of ultra-microscopic size which are present in vast numbers in al! air. 3119..00 So far ns the tipper limit of particle size is concerned it has been demonstrated by the South A trican studies that particles greater than ten microns in longest 63..50 dimension are, as a rule, of negligible importance. The data concerning the lower size limit of potentially hazardous dust is not so conclusive. Moir of Soutli Africa, 11..57 . wlto examined microscopically 120 dust particles obtained from two specimens oi silicotic lung, found that only 13 per cent of the particles were less than .0.5 microns \2 and about 36 per cent of the particles were less than one micron in diameter. The majority oi the particles. 00 per cent, were between one and three microns in size. 1.0 trace none The median size of the dust was found to be 1.2 microns in diameter. Drinker, in comparing the size frequency of the particles measured by Moir with the par none ticles measured by him of the dust found in tiie sputum of men employed in ore mills, found a close correspondence. These findings have also been corroborated the coal mining ,..l in brass foun- by Navrogordato. In connection with the lower limit of particle size of dust of pathological sig < tsons of quartz in nificance the following pertinent question arises: Aside from the evidence direct or indirect of the non-retention of minute particles of dust by tiie lungs, what I . : 56 Twenty-first Canr/rcss--National Safety Council TABLE 2 Average Dust Counts in Certain Dusty Trades Industry and Occupation Talc Mining and Milling: . Jack-hammer drillers ................................ Packers ........................................................ Muckers ........................................................ Crushernicn and cvlindermcn................. Slate Finishing Mills: Floonnen ...................................................... DLoisacdecrrsush...e..r....o...p..e..r..a..t..o..r..s................................4......................... Quartz Grinding Plant: Mill operators ............................................ Laborers ...................................................... GranPitaeckQerusarr.y...i.n..g.....a..n..d.....F...i.n..i.s..h...i.n..g...:................. I.cvner drillers .......................................... Jack'-haminer drillers ............................. Hand pneumatic tool finishers............... Machine pneumatic tool finishers.......... Plug drillers ............................................... Attendant labor (indoors)....................... Anthracite Coal Mining: Miners and helpers . : . . . ....................... Attendant labor ................... ..................... Bituminous Coal Mining: Coal cutters and loaders.......................... Attendant labor .......................................... Marble Cutlers ....................... .......................... Cotton Cloth Manufacturing: SilveWrweaarveersMaanndufsapcitnunreinrgs.:.............................. Dustv trades .............................................. Non-dusty trades ...................................... Dust exposure in millions of particles per cubic foot 2,160 50 45 14 1.598 1.2/6 312 173 83 144 112 59 36 37 17 232 31 1124" 33 0 ... 5 ... 5 Average per cent of quartz in dust None None NNoonnee N3one 3 3 3 99 9999 99 35 35 35 35. 35 35 35 1.5 1.5 1.5 1.2 1.2 1.2 None Xonn NNoonnee 11..77 1.7 evidence is there that appreciable percentages of ordinary industrial dusts ever fragment into those minute sizes less than 0.5 microns in diameter? The best answer to. this question would be data of actual measurement of such dust. Un fortunately we have but scant published data on the particle size frequency of dusts in the air of industrial establishments. In 1929 Fchncl made some particle size measurements in connection with the dust study of hard rock drilling in New York City. He reported the findings on three samples, which showed the dust which was less than 1 micron in size to vary from 1 to 15 per cent. Most of the dust in these hard rock drilling operations was between 2 and 5 microns in size. Badham, in studying the dust hazard among sandstone workers in Sydney, Aus tralia. measured some 16,000 particles of dust .in the air of work places and found that 67 per cent of these particles were about 1 micron in size. In a particle size