Document xKV5XbqON2kmvbOaNaE4DjEm

FILE NAME: National Safety Council (NSC) DATE: 1934 Oct DOC#: NSC154 DOCUMENT DESCRIPTION: Transactions of the NSC - 23rd Annual Safety Congress 1934 TRANSACTIONS National Safety Council Incorporated TWENTY-THIRD ANNUAL SAFETY CONGRESS Cleveland, Ohio October l to October 5, 1934 The Cleveland, Carter and Statler Hotels Copyright, 19S5, National Safety Council, Inc. Publication Plan T H E T R A N S A C T IO N S of the Twenty-third Annual Safety Con gress, National Safety Council, 1934, arc published in two volumes. The first, containing the General Sessions, the Special Subject Sessions, and the Industrial Section Sessions, is presented herewith. It is sup plemented by a smaller volume containing the sessions of the Street and H ighway Traffic Section, the Child Education Section, and Home Safety. The large volume is being sent automatically to the Industrial mem bers of the Council; the smaller volume is sent automatically to mem bers who are believed to be chiefly interested in those sessions. It may also be secured o n request by other Council members. For the benefit of many members who have found it advantageous to distribute copies of these T R A N S A C T IO N S to supervisors, fore men and others among their personnel, who may keep them for contin uous reference, the following quantity prices are quoted: 1 to 10 copies of the large volume, $1.50 each; 11 copies and over, $1.25 each. Copies of the smaller volume, $.50 each. T H E P L A N O F P U B L I C A T I O N is the same as that followed for the last three years. It is a condensed record. The papers of each session or division of the Congress have been assembled, edited with care and discernment to eliminate extraneous matter and abbreviate the less essential portions, and the concise remainder is presented for study and reference. Although not "complete" in the sense that every word is reproduced, it is an interesting and valuable record which em phasizes the memorable parts of each paper or address. The original manuscripts are on file in the Council Library, available for additional reference as desired. 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 cannot ac cept responsibility for the views expressed either in the papers pre sented or the discussions thereon. NA TIO NAL SAFETY COUNCIL, INC. 20 North Wacker Drive, Chicago CONTENTS PAGE Council Officers and Directors.......................................................................................... 4 Council Purposes and Policies.......................................................................................... 9 Annual Meeting of M e m b e r s . . . . ...................................................................................... 11 Annual Banquet ...................................................................................................................... 21 Subject Sessions-- Dust in Industry............................................................................................................ 23 Eire Prevention in Industry........................................................................................ .51 Fusion Welding and Cutting...................................................................................... 41 Industrial Nursing ....................................................................................................... 45 Industry and Its Motor Vehicle Accident Problem ......................................... 51 Maintaining Interest in S a fety .................................................................................. 59 Mechanical Methods of Handling Materials................................................... 67 N ew Workers ................................................................................................................. 73 Poisonous Fumes and V a p o rs.................................................................................. 79 Safety Equipment ......................................................................................................... 85 Safety Organization and P ro g ram ........................................................................... 93 Safe U se of Chemicals in Industry.......................................................................... 99 Safe U se of Electricity in Industry......................................................................... 103 T he Injured W o rk er..................................................................................................... 113 W h y People F a ll............................................................................................................ 121 All Ohio D a y ............................................................................................................................ 127 F E R A Safety Conference................................................................................................... 131 Industrial Safety Lectures-- Selling the Safety Idea.................................................................................................. '135 T he P sychology of the Safety Movement in Changing T im e s .................... MO Accident Prevention Equipment Manufacturers' Section....................................... 119 Aeronautical Section ............................................................................................................ 153 A. S. S. E.-- Engineering Section.................................................................................... 159 Automotive and Machine Shop S ectio n ......................................................................... 163 Cement Section ...................................................................................................................... 177 Chemical Section .................................................................................................................. 187 Construction Section ........................................................................................................... 199 Delivery, Taxicab and Bus Section ............................................................... 209 Food Section .......................................................................................................................... 219 Marine Section ........................................................................................................................ 227 Meat Packing, Tanning and Leather Industries Section........................................ 245 Metals S e c t i o n ......................................................................................................................... 255 Mining Section ........................................................................................................................ 209 Paper and Pulp Section ........................... 289 Petroleum Section ................................ 307 Power Press S e c t i o n . . . . ..........................: .................................................................... 325 Public Utilities Section......................................................................................................... 337 Quarry Section ........................................................................................................................ 349 Refrigeration Section ............................................................................................................ 357 Rubber Section ...................................................................................................................... 305 Safety Section, A R A -- Steam Railroad Section, N S C ............................................. 383 Textile Section ....................................................................................................................... 413 Transit Section ....................................................................................................................... 419 Wood Products Section........................................................................................................ 435 I n d e x ................................................. 415 National Safety Council Incorporated HONORARY MEMBERS Ar-'iit I.VI ION o r lloi.N ANIl S t I-.KI. Kl.l-.Cl Kll'.M. Nnniaer W. Camhiku. A ktiiitm W ii.i.ia m s ENGINEERS OFFICERS (1934-1935) John H. Long, President. I{<uir.Ki' 1. Cati. ix. Vice'President for Public Safety. 1). I). Fennell. Vice-President for Public Relations. Lew R. P almer, Vice-President for Safely Councils. A i.hert S. Rkgula, Vice-President for Engineer ill". C. \V. S mith, Vice-President for Tmlustrial Safety. j R. T. S olkxstex, \'ice-President for Menil>crslii|>. 11k. C. II. W atson. Vice-President for Health. A. W. W hitney, Vice-President for Education. W . E. W orth. V ice--President for Finance and Treasurer. W. II. Cameron, Managing Director and Secretary. EXECUTIVE COMMITTEE (1934-1935) A. L. A rmstrong, Eastman Kodak Company C. B. A uf.i, Past President. J. I: B an ash, Past President. C. W. B kkc.ouist, Past President. F. W. B raun, Wood Products Section. W. H. Camf.hon, National Safety Council. Rorert W . Cami-dell. Past President. T. H. Cakkow, American Railway Association. Ruiikht I. Catlin, Aetna Casualty & Surety Company. J. E. Culljnev, Bethlehem, Steel Company, I.kwis A . D f.R lois, Past President. Marcus A. How, Past President. D D. F ennell, Consulting Engineer. I). (.. 1'inn km ., Kansas City Safety Connell. C.U'T. li. W. Fiskk, Jit., Marine Section. R. B. F ortuin, Lehigh Valley Safety Council. H arry Guii.reiit. The Pullman Company. M erle C. H ale, Automotive & Machine Shop Section. G. T. H f.llmutii, Chicago, North Shore & Milwaukee Railroad t o . H on. H arold G. H oi-tm a n , Street & Highway Traffic Section. T homas P. K earns. Industrial Commission of Ohio. W aiter G. K ing. Past Pres idee' 4 Officers mid Directors $ I'uAXKt.iN M. Km: mi., li\a ns ton Safety tn unc il. John l. I.uno, The Delaware X: Ilmlsnii Railroad Corp. Tiios. II. MAcDnNAi.it, United Slates Department of Agriculture, l. .1. M fiikkx. Portland Cement Association. I W. M ii.i.ahh. Accident Prevention Manufacturers' Section. llAiiOi.n !.. M ini:!!, l. I. tinl'ont de Xcuiinn's X: l.'n.. Inc. Ain unit T Mnitrv, Past President, l i te K. Pai.mi it, Past President. C. l P ii i ii t o N i . Past President. ('. l. IsAl.sioN. W estern Pennsylvania Solely ( nnucil. A im HT S. Kkuiii.a. Industrial Relations Counselors, Inc. I I. Coi.. II. A. IsiANINta It, Past President, t i t o li . i. l. S a xi ni;11, Cenerai llclcric Company. Rui-.iut I., `' f i l m u t , l.ottiseille Safety Council. 11Aititv A. S e l l i n i / ., Uniteti Slates Steel Corporation. Cii.Mtn.s 1!. S cott, Past President. I. r.sm; D. S fv.moi'k. Aeronautical Section. C. \V. S mith, Slandard Oil Company ( liitliaiia'I. W'ai.tkh Di:xt S mith. Delaware Safety Council. U. T. Soi.i:x.sTi:x, lillinlt Service Company. Ci.Atti xti: P. T.wi.oit, Massachusetts Safety Council. C. P. T h| man, Past President. J. A. Voss, Metals Section (ii inti.r If. W'akifi.. Union Pacific Railroad Company. Dit. C. II. M aison. American Telephone X Trivi; rapii Company. A. \V. W'iiitnfv. Xational Ilureaii o f Casualty X Surely Underwriters. W. l. W'ninil, International Harvester Company. \ it 1111 -it II. Vt if.\ii. Past President. DIRECTORS (1934-1935) PmoficU'k AitciiFtt. C hild lithication Section. W i n am F. Ai.-nitin. Safety Die.. Milwaukee Association of Commerce. A. I.. AitMs'iitoNt;, Kastman Kodak Company. M n.i.iAM II. IiAKFit, Quarry Section. .1. I. P ana sii, Consultili; iineiuecr. II D. P.axta, Paper X: Pulp Section. I.i;s;I si M. P.FCK, United States Ptihher Products, Inc. W . A. IIfnnftt, M'orccsler Safety Council. ( . W. Pi unpriST, Western !ilt-c trie Company. D n.Hi S. ItiAMt, I.ihertv Mutual Insanirne Company. I'., h. P i.ank, Jones X: l.auphlin Steel Corp. ( I1. 1toitKFNiiaofw Kenosha Safety Coonicl. I . W . 11it \ f N, Wood Products Section. I or. Pm i. II. Itl;(If KMAX. St. I.ouis S a n i e t oiiucil. I'i.'i.sIon D. Cai.i.p .m, Ilallimoi'e Safety Conned. M. II. C amiis'N. Xational Safety Council. I . J. t Ait \T.v. ( 'liic.TNo Safety Council. I. II. C.uu.oW, American Railway Ass.a iation. 6 Turn tv-third Annual Safely Congress--National Safety Council R odent I. C ati.i n , Aetna Casualty & Surety Co. Caw. C. C lements, Refrigeration Section. Kiiscok D. Co.Nt.iN-, Kalnvay Safety Council. H. H ewiekt Corson, Safety U e p t N a s h v i l l e Chamber of Commerce. J. K. C iii.l i.nev, Bethlehem Steel Company. E dward D a n a , Boston Elevated Railway. K. A. D aviuson. Consulting Engineer. R ichard H. D avis, IJlackstonc Valley Safety Council CttAULES D. D aw son , Grand Rapids Safety Council. L ew is A. D kB lois, Consulting Engineer. J ay E. D ecker, Mason City Safety Council.. J ames B. D ouglas. The Philadelphia Gas Works 'Company. Louts I. D u p l in , Metropolitan Lite Insurance Company. C harles II. Kames, Textile Section. D. D. F en n ell, Consulting Engineer. 1). L. F en n ell, Kansas City Safety Council. D onald A. F in k h e in e r . Toledo Safety Council. C a it. E. W. F is k e , J r., Marine Section.. H oward U. F onda, Burroughs Wc-llcoinc & Co. ( U . S. A .) fne. R. B F outuin, I.cltigh Valley Safety Council. F. . N. Goi.dstine. Construction Section. I O n t o M. G raves, T he General Cnishccl Stone Co. H arry G lti.hert-. The Pullman Company. Tsaiaii TIai.e, The Atchison, Topeka Sr Santa Fe Railway Co. M erle C. H ale, Automotive & Machine Shop Section. Major Tiou-ixa H. H andy, Richmond Safety Council. D. T. H arrington, United States Bureau of Mines. G. T. H e l l m u t ii. Chicngofi North Shore & Milwaukee R. R. Co. C h a s, E. H ill, N ew York Central Lines. 1Ion. H arold G. H o f f m a n , Street & Highway Traffic Section. C laude J. H olding, Albany Safety Council. J u lius W. I I okke. Hudson County Safety Council. H arry D. I m m e l , Pennsylvania Dept, of Labor S- Industry. Lf.x J e n s e n , Berkeley Traffic Safety Commission. E dgar P. K.mu.E. York County Safety Council. T homas P. K ea rn s , Industrial Commission of Ohio. K. T. K eller, Detroit Industrial Safety Council. Ira V. K eener. Pennsylvania Salt Manufacturing Co. E. J. Kkf.h , Public Utilities Section. F r a n k l in M. K me.ml. Evanston Safety Council. C. L. LaFount.mnk, Great Northern Railway Co. F rank J. I . a n a i i a n , Fort Pitt Malleable Iron Co. J o h n L aukrman, Meat Packing. Tanning & Leather Industries Section, S imon L azarus, Safety Council. Columbus foilin') Chamber of Commerce. J oseph L ti.i.ic ii, Rochester Safety Council. D r. K. M. L ittle. N ew York- Department of Education. G. O. Lockwood. P e t r o le u m Section. J. L._ Long, The Delaware & Hudson Railroad Corp. IV. K. I-ovd, Safety Div., Birmingham Chamber of Commerce. Officers tnttl l)irectors 7 A. E. I.iinhsti apt, lli livcry, T;i.\ir;il/ X: Bus Section. Tims. JL M.u Donau), United States Department of Agriculture. L. T. McA rthur, I'curia Safety Council, Milt.Kit McClintock, Harvard University. T. IT. McKk.vnev, llliiii/is Steel Company, Sontli Works. A. 1). McW horter, Safety Div., Memphis Chamber of Commerce. II. T. M artin, 1'isic Rubber Company. I. O. M a rtin , Employees' Publication Section. F. W. Matson. Minnesota Safety Council. K. J. M kiirex, Portland Cement Association. T. O. M eisnek. Power Press Section. W m. G. M f-tzck, Mining Section. I. \V. Miu.Aitn, Accident Prevention Etpiipmcnt Mamifacturers' Section. 11Aitoi.D I.. Mtni.h, E. T. dnPonl de Nemours X Co., Inc. H enry .1. MixKfit. Elizabeth Safety Council, l.AWttK.NCF. M. M oore, Easthay Safety Conncil. K. I'.. Mmti.KV, Industrial Acciilent Prevention Associations. J o hn A. C art el, Carnegie Steel Company, CirottrK C. A. Ore, The Detroit Edison Company. I. kw R. P ai.mek, Ei|nitalde Life Assurance Society. J ohn C. P arkek, Brooklyn Safety Council. Davhi A. P a t io x , Newark Safely Council. C. E. P ei i i i :o m :, American Mutual Liability Insurance Company. CiEX. G eorc.i: 1!. PiLi.smtitv, W ar Hcpartmcnt. J. H. P ower. Seattle Traffic & Safety Conncil. C. E. Ralston, Western Pennsylvania Safety Conncil. At.liner S. Rixui.a, Industrial Relations Counselors. Inc. I. t. Cot.. 11 eNItv A. R eninger, Lehigh Portland M a r in l s R iteii, Paterson Safety Council. (i. E. S anforu. General Eletcric Company. H enry G. S c iia ff n i it. Erie Safety Council. T. A. Sc hen DEI., Food Section. Cement Company. Rouirt L. Sen m itt, Louisville Safety Conncil. II. V. St n itr.ini.it. Transit Section. 11 Mtitv A. Sciilu.TZ. United States Steel ( 'orporatinn. Cii mci.es II. St orr, Bureau of Safety, Inc. L ester 1). S ev.moi.'r, Aeronautical Section. Hare S. SiiAitrzKit, Utica Safety Conncil. R ay II. S heets, Madison Comity Safety Council. Dit. L. A. Sitounv, Bethlehem Steel Company. E rnest L. S im on d s, New Haven Safety Council. Lei: h. S keei., Cleveland Safely Council. (.. W. S m i t h , Standard Oil Company (Indiana). W alt tit P i nt S m i t h , Delaware Safely Council. R. I. Shi.enstin, Elliott Service Company. F. C. Si-niNi;, l.ansdulc. Pa. t i i o m. E R. Sri.l-ilENS, S a f e t y ll i i rean, llnlValo t ' l i aml i er of C oiiiiim rce. L ia m s S. S torks, United Railways X Electric Co. S 7 y-thiril . innttil Suft ' l v C -- Xa/ioiial Stifc/v ( mtnf D r. F. M. S ui.zma.v. Troy Safety Council. At.n;ri> H. S waynf, General Motors Corporation. C i.ark.vck P. T avi.oi!, Massachusetts Safety Council. A rthl'r XL Tout-:. Cuusultmy Marine Enyinecr. XX'. XXL T kf.nch. Schenectady Safety Council. \ \ \ I). Ti;ttin:vn.i.F.. San Antonio Safety Council. I. A. X'oss, Metals Section. H. A. XX'.m.kkr. Rubber Section. G f.orof. H. XX'akffi., Union Pacific Railroad Company. D r. C assius II. XVatsox, American Tclcpbone A Tcleyvaph Company. H arry M. XX'f.iuu-'.r. Illinois Hell Telephone Company. At.rtF.RT C. XX'niTK. Jn.. Sprinyficld Safety Council. S. E. XX'imtinc, Liberty Mutual Insurance Company, A. XX'. XXTiitnf.v. Xational Ilnrcau of Casualty A Surety Underwriter.-.. XV. H. XX'i n a n s . Union Carbide A Carbon Corp. Ur. C.-K. A. X\tins!.o\v, X'ale Medical School. H arry XX'isf.. S r., Chattanooga Safety Council. J. M. XX'oltz. Youngstown Sheet A Tube Company. XX'. E. XX'ortii. International Harvester Company. E. J. Z auft. Safety Ilurcau. Duluth Chamber of Commerce. Kari. XX'. Z immkrmas". Safety Die.. Syracuse Chamber of Commerce. J. r.. Zi'.ok. Cement Section.  m id i ' , mu to p'.it otmcil re in>rs of tue to lay ben developed 'i action in 'Ingram for Regales and I from the F. 1934 . in session tgs and my it you are program to ady taken h, because with the c solution citizens is -'i:; toll of grim that bway coinsure. and id disaster, mend your . :ion with upon our . LT. Hoffman, aslmaster. b. of New surpassed, America.' dar mono- evening; uc Council Tl !' li N T ) ' - T II l R U A N N U . U, S A T T T Y C O N G R E S S NATIONAL. S A T RT Y COUNCIL t Dust in Industry V FRIDAY AFTERNOON SESSION October 5, 1934 Tlie session devoted to a discussion of llust in Industry was called to order l>v Dr. E. (4. Meiler, Director, Industrial Hygiene Laboratory, Employers Mutual Lia bility Insurance Co., Milwaukee, who presided. Dr. Meiter briefly welcomed the delegates and then introduced the first speaker. Types of Dust That Cause Occupational Diseases By LER O Y U. GARDNER. M.D. Director. Saranac Laboratory for the Study of Tuberculosis, of the Edward L. Trudeau Foundation, Saranac Lake, N. Y. The speaker -aid in part: Experience lias demonstrated that the lung lb-ties can lolcrii'e very large amounts of most kinds of foreign dust particles without serious interference with iunction. The lung may be intensely pigmented by colored dusts with no evidence that respiration is impaired. Lut du-ts composed, in whole or in part, of silica have been shown to be dangerous because tiiev stimulate the growth of the connective tissues of the lungs and bring about the formation of scar tissue. This destroys the normal elasticity of the organ which is necessary for respiration and it thickens the deiieatc membranes so that a free interchange ot gasses is impeded. Fortunately, these results only follow the prolonged inhalation of very large ipinntitfi s of silica. Experiments have demonstrated that the Injection,.)! -iiie;. into tiie tb-iao ol anitn-Pi kids *)) ceil- where the substance lodges and evc'.P's ng intln.i.mr.t*- n. When healing takes place a very dense and characteristic kind of sear tissue forms. Most non-siliciou- du-ts produce no iiulammation and very little scar. It has keen shown that such changes do not follow the injection of silica unless the particles are very fine, three microns or less in diameter, and unlos enough of them localize in one area. With larger particles the rale of reaction is so slow that little change occurs within a year. As a general rule, the finer the particles, the more rapid the cellular response. The reaction to line silica begins within four or five hours and it continues for a period of years. It the silica is combined with bases in the form of silicates, it rarely produces such active and progressive changes. The silicate of magnesium, asbestos, does cause the formation of scar tissue iu experimental animals and in the human lung, hut most other silicates are not generally recognized as irritating. Recently it has been claimed that a hydrated silicate of aluminum and potassium, called scricitc, is responsible for mo-t of the cases of silicosis. This silicate, a transformed feldspar, is oiten associated with quartz and it has been identified iu the lungs of persons suf- 4 Tieenly-lh'ietl . Iiuutal Safely Coiujress-- Xalionat Safely Caain:! ferine from silicosis. However, ;it least two types of senate have failed i`> exeitc significant changes when injected into animals. Experiments with this -ubstance are still in progress. Kaolin, an altmuno-silicatc of potash, lias also produced quite characteristic changes in the limits of rabbits, lint our present knowledge docs not permit us to assume that silicates as a class will produce serious tissue damage. Most observers now believe that uncomhincd silica, or quartz, is poisonous to the tissues because it is slowly dissolved in the thuds of the body. Certainly the majority of the experimental observations suggest a chemical injury, hut it is diffi cult to understand hmv enough of such an insoluble substance as quartz could he dissolved within eight hours to produce a well marbed. acute inllaiimiatiou. [f solubility were the only factor one should discover a more active response after the injection of the more readily soluble silicates, hut such is not the ease. For merly it was held that silica produced its effect mechanically. The hard sharp quartz particles were believed to ahraid the hum surfaces and excite the forma tion of scar tissue as a manifestation of healing. This theory is no longer tenable for when animals arc injected with other hard, sharp particles like diamond, carbo rundum or aluminum oxide, there is no inlianimatimi and practically no i rmatinn of scar tissue. Ultimately it may he shown that the irritation of silica b due to some unrecognized property possibly related to its atomic structure. When quartz particles are inhaled they produce three specific effects which are not excited hv any other type of dust yet studied. They alter the behavior of the pulmonary phagocytes; they stimulate the formation of circumscribed nodules of scar tissue: aitd they subsequently increase the susceptibility of the lung to infection, espe cially tuberculous infection. Phagocytes that ingest too many quartz particles are killed by this irritatitte substance. As the cells die they liberate their burden and several new phagocytes come out to take it up again. I!y a repetition of this process enough phagocytes accumulate so that many of them ingest only a few particles. Under such circum stances the stimulus is not strong enough to kill but merely accelerates tin- motility of the cells. They naturally tend to leave'thc air spaces, enter the lymphatic vesst Is anti accumulate in the lymph nodes. This process becomes more rapid tattler the iullueuee of the irritating silica anti very considerable numbers of particles are consequently localized in the turtles. After six or eight years the quartz in the nodes has caused a marked over growth of the (bruits elements in these structures. Ultimately the reaction develops to such an extent that the node is entirely replaced by a mass of coarse, glassy scar tissue fibres, often several limes as large as the original node. Stieit nudities en croach upon and compress the lymphatic vessels. The drainage system of the lung is choked and effective removal of subsequently inhaled dust is gradually diminished. Dust now accumulates around the lymph vessels and sheets of scar tissue develop in this location. These preliminary changes do not constitute tire disease, silicosis; tit. . uvoive only the lymphatic system. The respiratory tissues are not appreciably aoV.-tvd. In good stent X-ray hints these preliminary changes may he visualized as a thick ening and heading of the shadows cast by the blood vessels together with a widen ing of the shadow of the. root of the lung. The blood vessels arc thickened because the most important lymphatic vessels course through their walls. The beading is due to the minute nodules of silicotic scar tissue in the lymph nodes within the lung. The root shadow is widened because of the silicotic reaction itt the lymph Modes in this location. If still more dust is inhaled it can no longer he effectively carried off through the lymph vessels. The phagocytes now carry it into the walls of the air spaces. Often the cells group themselves in nodules but sometimes they arc scattered. In these loeations the silica again stimulates the formation oi scar tissue. The result is a general thickening of the septa between the spaces and Modulation throughout the functional portion of the tune. This change seriously interferes with function as interchange of gas cannot take place through the thickened walls of the air spaces and the tissues lose their normal elasticity. Less involved air spaces dilate and their walls stretch, producing the condition known as emphysema, which is also incom patible with effective respiration. With the formation of silicotic nodules in the functioning parts of the lung the ' Climn-* ailed to excite this sui.stahoc yrodured quite mowledge does' tissue damage. poison, ms i.i Certainly the . hut it is rlilti.uartz could he Animation. If response alter die case. I'nrie hard sharp tc the forma longer tenable umnud. carho11 formation -ilica is due to rts which are `iiavior of the nodules of scar infection, espe- this irritating phagocytes :ph phagocytes r such circum- the motility .`wnphatic ves ratiid under ' of particles narked overu'tiuii develops -r. classy scar nodules enn of the nine -llv dimini.-hed. '.'sstie develop . they involve -ihly attected. i as a thickvith a. widenAcued because no heading is les within the in the I\mpit 1 off through die air spaces. -cattcred. In The result n throughout with function he air spaces iilatc and their also incom- the lung the ./ ( t . ' ; l> n s l 11 h n li is lr v disease, silicosis, is said to begin. On the X-ray lihirsiidi nodules east clear cut, round shadows. As they increase in miuihcr and size they Idol out the formerly accentuated linear shadows o| the Idood vessels. In a well marked ease hold ping 11elds may he thickly seeded with hundreds of such sharply defined, rounded, nodular shadows. ^ Where there is emphysema, often at the liases, no markings are visible and the film appears Idaek. Jhe condition of silicosis is a progressive one and it continues to develop niter a man has left his dusty occupation, Serious results only follow, however, when he leaves witli many nodules in the Inns* tissue itself. As such nodules increase in size they replace important functional elements. Obviously the continued growth oi only a few nodules situated in the lymphatic system could have little cited other than to increase the obstruction already present. I he serious part ol silicosis is its frequent complication by tuberculosis. This may arise from reactivation of a pre-cxistant latent infection or it may result from a new infection from without. The dancer ol infection increases with the amount of silicosis present. The course ol the infection in the silicotic is usually chronic and it'often tails to produce characteristic symptoms for mouths or years aider its onset. Many times it is accidentally discovered in routine X-ray examination ot .croups of active workmen. However, evidences of disability are much more marked in silicotic individuals with infection than in those with uncomplicated disease. Occa sionally tuberculosis may run a very acute course in the silicotic subject Imt this is also true in other persons. The cause of the susceptibility of the silicotic lime to tuberculosis is not perfectly understood, hut it would seem that- the action of the silica on the tissues creates a medium favorable for the growth of the bacteria. The tubercle bacilli multiply and a slowly progressive tissue reaction ensues, hut the usual clinical symptoms of tuberculosis are often held in abeyance for a long time because the chances for absorption of poisonous products of infection are mini mized hv tile obstructs'! lymphatic system. It is also possible that some of these poisons may he absorbed on the silica particles, as Omnibus has suggested. Ulti mately the infection pains the upper hand, symptoms develop and death from tuber culosis ensues. The only other, type of dust which is generally recognized ;is a cause of severe pulmonary injury is asbestos, a silicate of magnesium. This substance is fibrous in character and is more readily soluble than quartz. Apparently the jVoteetivc upper respiratory mechanisms seem inadequate to prevent the inhalation of many such (litres and even quite lonp sites may penetrate into the liner bronchial tubes. These structures have irregularities in their walls which seem to hold the fibrous dusts. In this location the asbestos particles are surrounded and inpesled by phago cytes. The cells do not seem to he particularly irritated for they are not espe cially numerous nor do they liberate rapidly into clumps as in the ease of phagoeytes dealing with quartz. Apparently most of them carry their burden of asbestos irapmenls directly into tile walls of the tubes in which they lie. The mildly irritatiue dust sets up a proliferation of the connective tissue cells in the wall- re-.ul:inp in eollar-like thickening of ib.- tubes. i V-utraetioii of the new connective tissue narrows or closes the tube ami thereby sinus off the inpress of air to the more peripheral air spaces. These spaces then collapse, a condition known ns atelectasis. This in itself is a cause of fibrosis or scarring of limp tissue. The result is a fibrosis oi numerous relatively small areas in the bmp due to the. eollar-like coiistrietinp fibrosis about many small terminal bronchial tubes. The lymphatic system seems to play little part in disposing of asbestos dust aiuL-^-.-miisipiiilicaiit amounts of this dust are found in the lymph nodes. Not a tew eases of ashestosis die of tuberculosis or bronchopneumonia hut the prevalence of the former infection is probably much less common than in silicosis. Surveys of-large roups of asbe-tos workers fail to reveal such a high incidence of tuberculosis as found in similar studies on silica workers. The inhalation of unusual amounts of non-siliceous dusts apparently fails to pro duce significant alterations in the lung. It is of course possible that injurious ones may ultimately he discovered, hut none arc recognized today. The uon-siliccous particles enter the lung and arc ingested l>v phagocytes as . in the case of quartz. The cells are not stimulated to move very rapidly and as a consequence tunny of them remain within the air spaces for a long time. Some, particularly those con- I / 26 Tw enty-third Am inat Safety Comjress-- A'atioual Sa fe ly Cuancil taming relatively lew particles. make tlieir way into the lymphatic system a:nl accu mulate in the lym[ih nudes. In sufficient concentration. or perhaps because they are mixed with small amntmt.- oi silica, they set ni> a low trade, iiiiu-prugrcssive chronic ndammatinii. Hut this reaction results only in a little thickening in the lymph nodes and about the lymphatic vessels. The lung tissue may lie variously pi.ementcd, b.ack irom coal ur red irom iron, hut there is no formation nt scar tissue that inter feres with function. The susceptibility to tuberculosis oi the person with such, pig mentation is not increased hut it is apparently quite definite that pneumonia is unduly prevalent in coal millers and that chronic bronchitis results from the iniinlat'.-.-n of cement. The X-ray films oi men working in non-siiiccutis dusts shows cither nothing at all or a more or less marked accentuation of the linear shadows cast hy the hlcod vessels. This, uf course, is due to the chronic intlammatorv changes about the lymphatic trunks in walls of blood vessels. 1 he eliccts of mixtures of free silica and non-siliceous materials are less cieariy defined and should receive more serious attention. It would seem unwise to assume, as has been done in the past, that the non-siliceous substances serve only as inert diluents and that only the quartz component of a dust is of significance, Expcrimental and clinical data are accumulating which suggest that at least some other dust# may materially modify the action of quartz, both in its capacity to produce nodular fibrosis in the lungs and to increase (lie susceptibility to tuberculosis. For example, animals inhaling heavy concentrations of a mixture of equal parts of pure silica and hematite dust for eight hours a day over a period of 14 mouths have shown not even the slightest indication of nodule formation in the lung, whereas pure quartz dust, inhaled for only two hours a day. .proLuces definite nodulatinn. It also seems to he true that animals uhaiing such a mixture arc much less susceptible to tuberculosis than those exposed to pure quartz. In the ease of the human iron miner, some lungs show definite silicotic undulation, others only a very few nodules and many no nodules at all. AH exhibit heavy deposits of iron particles with a cellular connective tissue reaction. When these findings can he correlated with chemical analysis of the lung tissues and the approximate amount oi rock work .'.inch these miners have performed, some relationship between the exposure to silica and the fibrous nodule iormnliou may be established. Tuberculosis in these iron miners is apparently less prevalent and much less severe than in men exposed to pea- silica. What has been said of iron miners is also probably' true of foundry workers and coal miners. It is generally accepted that men in the latter occupation have less tuberculosis than the average for the age period: lummins believes that they have the infection hut that it is so atypical and benign in its manifestations that it escapes diagnosis. Mention should also he made of mixed 'lusts like certain slates and granite c- teaming large amounts of tree silica in combination with silicates. Experimentally these sn!ii:mecs behave atypieaily ami do not produce nodular fibrosis unless there is complicating infection. The same may also lie true in human beings. Unques tionably site'n dusts are capable oi producing typical silicotic nodules and tt;ey predi-pose to tulii-reulosic. Frog! a theoretical standpoint they should reeeice much more intensive study to clarify our views on the whole subject. At the present time it appears that the action of their quartz component is modified and partially neu tralized by the other substances which they contain. Using Exhaust Systems and Respiratory Equipment To Protect Workers Exposed to Dust By S T U A R T W. G U R N E Y and D A V ID S. B E Y E R Liberty Mutual Insurance Company, Boston The speaker said in part: A number of our states have had references to dust elimination in their labor laws for a good many years, hut no state has as yet thoroughly enforced these laws. The codes oi live states which wc investigated provide that grinding, huffing and polishing wheels should he exhausted, although two of the states exempt irom these provisions wheels on which water is used. Mtuiutj relatively few particles, make their way into the lymphatic system ami accu mulate in the lymph nodes. In Millicieiil <.oncriitrati"n, or p< rhap< because they are mixed with small amount'' *t silica, they -.el up a low prude, nun prupressive chnnuc mllamm.it i- *ti. lull this reaction result- 111\ in a little tlncl-cmm; in tin* lymph nude* and about the lymphatic \c>-c!s. The lunp ti-'Mic may he variously pipmeiited, Mach in-in coal nr red trmu treat, hut iIutc is no formation of scar tissue that inter* :ercs with iuiulioii. The Mi-roplihility P* (iihcn uhsis ol the person with such pit;mentation is nut increased Imt it is apparently <piile dchnilc that pncmuniiia is tmdtdy prevalent in coal miners and that chronic bronchitis results from the inhala tion of cement, The X-ray hints of men working in non-siliceous dusts shows either nothing at all or a mure nr te-s marked acceutualum t( live linear shadows cast hy the blond \cssels. This, of course, is due f<> the chronic nllaminatury changes about the lymphatic trunks in walls of blood vessels. The elfects of mixtures of free silica and non-silircuus materials are less clearly defined and should receive more serious attention. It would seem unwise to assume, as has been done in the past, that ihe non-siliceous substances serve only as inert diluents and that only the quartz component of a dust is of significance. Experi mental and clinical data are aeeumulatiup which support that at least some other dusts may materially modify the action of quartz, both in it- capacity to produce nodular lihrosis in the limps and to increase the susceptibility to tuberculosis. 1*Tr example, animals inhaling heavy concentrations of a mixture of equal parts of pure silica ami hematite dust tor cipht hours a day over a period oi 14 months ha\e shown not even the slightest indication of nodule formation in the lime, whereas pure quartz dust, inhaled tor only two hours a lay, produces definite undulation. It also seems to be true that animals inlulmp such a mixture are much less susceptible to tuberculosis than those exposed to pure quartz. In the case of the human h"U miner, some limps show definite silicotic undulation, others only ;v very few nodules and many no nodules at all. All exhibit heavy deposits of iron particles with a cellular connective tissue reaction. When these findings can be correlated with chemical analysis of the limp tissues ami (he approximate amount oi rock work which thcM* miners have pertormed, >mr relationship between the e\pi>Miiv to "ihca and `the hbrons nodule formation mav lie established. Tuhereulons in these ir`*n miners is apparently less prevalent ami much le>s severe than in men exposed to pure >ili<;a. What has been -aid of iron miners is also probably true of foundry workers ;uu! coal miners, ft is generally accepted that men in the latter occupation have less tuberculosis than the average for the ape period; Cummins believes that they have the infection hut that it is so atypical and benipn in its manifestations that it escapes diagnosis. Mention should also be made of mixed dusts like certain slates and pranito containing lar.ee amounts of free silica in combination with silicates. Experimentally these substances behave atypically and do not produce nodular fibrosis unless there is complicating infection. The same may also he true in human hemps. Unques tionably >uch dusts arc capable of producin'* typical silicotic nodules ami they predispose *ci tuberculosis. Emm a theoretical standpoint they should receive much more intensive study to clarify nur views on the whole subject. At the present time it appears that the action of their quartz component is modified and partially neu tralized by the other substances which they contain. Using Exhaust Systems and Respiratory Equipment To Protect Workers Exposed to Dust Hy S T U A R T W . G U R N E Y ami D A V I D S. B E Y E R Liberty Mutual Insurance Company, Boston 'Ihe speaker said in part: A number of our slates have had references to dust elimination in (heir labor laws for a c.nod many years, hut no stale has as yet ihnrouphly enforced these, laws. The cdvs of live states which we inveMipated provide that prindiup, bnflinp and polishing wheels should he exhausted, although two of the states exempt from these provisions wheels on which water is used. This seems ill-advised, sinee a study of wet and dry grinding in Connecticut by Winslow and fiicenbmg lias shown that the application of water does not by any means eliminate the dust hazard. It may he remarked that, with everything else equal, a high static suction will nice a higher velocity at the point of origin of the dust, fume or pas than a lens one; hut this alone is not a measure of the effectiveness of any exhaust system. Wisconsin has adopted the principle of specifying a limit to the numher of dust particles of respirable size per cubic foot of air. After all, this is what we are primarily interested in, to keep the dust contamination down to a point where it will not he harmful. 'Hies, variations and conllictiup provisions in slate codes merely reflect the pen- era! lack oi authoritative standards. It is aeeordin;dy fortunate that definite steps are now heius taken by the American Standards Association to develop the propel basis for such codes. There are two committees working on this problem; the Ventilation Code Committee, sponsored by the American Society of Heating & Ven tilating engineers, and the Exhaust Code Committee, sponsored hy the Inter national Association of Industrial Accident Hoards and Commissions. It is also arranged to appoint sub-committees to take up five specific subjects: Abrasive cleaning, chromium plating, granite cutting, rock drilling, and spray coating. Itf addition, a Sub-Committee on Fundamental Principles of Design and Operation and Maintenance of Exhaust Systems will lie appointed. The two most important considerations in an effective exhaust system arc: 1. Velocity of air How; 2. Arrangement of the inlets (from the standpoint of near ness to the dust source, shape, etc.). Many au installation that is otherwise all right fails to remove the dust success fully merely because there is not enough air being drawn through the system. In a series of tests that were conducted under actual working conditions by Theodore E. Hatch, Department of industrial Hygiene, Harvard School oi Public Health, a machine used in dressing stone was employed, and it was noted that with au air llow through the hood of 2.10 cubic feet per minute, there were over one hundred million dust particles in the surrounding air. When the air llow was increased to a little over 251) cubic feet per minute, the dust concentration had dropped to b>rlv million, a marked improvement. As the air llow was further nena-id. the drop In dust concentration was relatively slower, and it tools a volume of about ah'O cubic feet per minute to bring the dust concentration down to ten or lit'teen million particles per cubic foot, which was considered reasonably safe for this type of dust. It is accordingly possible sometimes; to take an installation that is not satis factory and. if the remainder of the system is well designed, by merely speeding up the blower or adding a larger one, to bring about the desired results. Another very important consideration is to get the inlets of the exhaust system as close as possible to the source of the dust. The drop in efficiency as we get further away from the inlet is really surprising to one who has not studied the prin ciples involved. It should be remembered that if we have the open end of an ex haust pipe or air duct in operation, the air tends to flow in from all sides, even from behind the opening. As we move away from the end of the pipe, the velocity drops very rapidly, so that even at a distance of five inches from the hood the velocity may he less than 10 per cent of that right at the hood inlet. This is the most important consideration to keep in mind and one which is frequently lost sight of in designing exhaust systems. It is not unenmmon to see an exhaust inlet a few inches in diameter with which the person making the installation hoped to draw dust from a distance of. several feet, hut the air flow 'even a foot or two away from the entrance to the inlet may he negligible. * Still another important consideration having to-do with (lie design of the inlet, is the addition of a llange. The effect of this flange is to ml down the air that would llow in from behind the opening, thus drawing it nearly all front the front. Thus the efficiency of the system Is substantially increased and the scope of the e x haust extended appreciably, without Increasing the power consumption or otherwise adding to the expense of keeping up the system. There are also other considerations of perhaps lesser mporlnncc. For example air cannot he `"pulled" from a distance by merely directing an exhaust pipe toward the point in question, but it can he "pushed" or blown, directionally, for a consider- Ji> T u 'i'u t y -t in n t .'im n m i . S u / r / v ( r>iw/n*>\<-- A ii/m iu tf u ij c ly CoiuirW ible distance. T h is |>rinciplt' mav he m o l adsanta.^omisly in dm.-ctui" the diM ward the opening fit the cxhnu>t inKt and thus ellini! the <lrsin.il icsnlts uith a haver exhaust velocity and power c n-uinpt i<>11 than would hr requited if suet i>n lie were <lr|*en<lr'I upon. J his principle h.t< hern applied rlleeti\rly it dNlh:iq material cotUammp ad>esP>s, where tin* cxhaiM inlrt is placed at me side <*f the drdl an! a small air jet at the opposite >iI: of the hlnwin;.' aerss the tabh turn< the particles that would lie out im m this side ami directs them hack into the exhaust system. It is al-o heine. applnd t* foundry shake-out work. Other eimsidei at inns in dr-dcniim xluiM systems include the elimmatinn " I Miinm''>;ii'y hemh nr curves. lit' prv i--ioii ni rlc.iu out door--. ami the prnper `on* structinu ni jnil its. Where there is a eemrat ventilating installation and one *r iuor*- exhanst systems, care must he taken in m-c that they do not eniitliid with earl other. Alter an exhaust system has lurn installed it shntihl he tested by takim; ;udial 'Imt om its to see that the lust is really beim* cut down to the desired point, and such rouuts should he taken at intervals alter the installation has hern made, to see that it is still funetioiiiiiu properly. '1 lie fact that the dust particles that cause the (rouble are so small that they are invisible under ordinary conditions (less than 10 microns or l/`25dOi!i <.i an ineh in diameter) olteii makes it hard to convince the practical plant manager that there is any dust present: it also m akes it unpo-dblr to tell, without the Use *i spe cial instruments, whether the completed exhaust sv>tem is actually ruin vim* the (hi't. It mieht seem like an insult t> one's intelligence t say that alter an exhaust system has once been installed it should he maintained in ipn>d operating condition. However, the numerous eases one encounters in the plants where this ulviou> nee:-., site is nn( carried nut. indicates that it is really one of the majnr considerations in connection with the elimination of hist nr fumes. Cases are not unknown where the hlnwer has in some maimer become reversed so that the air is heme, ejected and dillusine the dust, rather than drawing it in; other instances where tin* clh* eiency of the system has been lowered or it< value tinllifwd by ehiauim! up. dis connection or weariim out of the pipim;. etc., are all to cimm*n. One concern, of which the writers have knowledge, lias a "l.*" lube permanently installed in one ot its main exhaust systems so that the foreman nr safety man can tell at a ehmev whether there art* any changes that would indicate a hreak-d*wn in the systun. All such iiistallations should have regular inspections hv some compe tent person as a routine part ot their upkeep. It will he sufficient here to di.-cu-s respiratory equipment very hriclly. The simplest form of this equipment is the Idler respirator. Such respirators have a definite value for temporary u-e such as sweeping up, clcatmii; out bins, shovetiui* materials, etc., but they require careful fitting and constant supervision to sec that they are hem;: properly used. it is our opinion, after watehim; tin- sincere efforts in a number of plants to enforce tin- me of these respirators, that it is rather impracticable to require them I he used on full time operation. One notice-' the men. under these conditions, -nrTc`ptitioii'ly puduiu: die respirator aside and .qaspiir.; in free air like a lidi out of water. <Vrtainly. il* they are to he uwd any considerable leueth of time, fre quent rest periods shuild he allowed where the men can el out iut the free air hr a few minutes refreshment. There are also the larr.e air-lVd hlm ts. with which iu-l of us are familiar used for saiulbladme, etc., which have hern carried to a Inch slat* of perfection for the purposes to which tiny are adapt d. We believe, however, that much more use could he made advantageously of the type ot apparatus that lies midway betweenthe filter respirator ami theair-led helmet, namely, the Ii;<ht, air-fed re-pirator which covers the nose and mouth and leaves the rest of the face exposed. W itha liidit hose attachment, this device oilers considerable freedom of movement, and if air outlets were supplied so the hose could he. quickly transferred from one outlet to another it wouhl seem to. he practicable to use them over a considerable area. They afford the advantages of a pure air supply without excessive weight and without the restriction to breadline that*!-; imposed by the filter respirator. u uji in i nauMt j The Medical Supervision of Workers Exposed to Dust By w. j. McCo n n e l l , m.d. Assistant Medical Director, Metropolitan Life Insurance Co., N ew York City Tlie speaker said in part: The harmfulucss of dusts varies widely in accord ance wi111 the physical and chemical natures id each individual substance. Certain dusts are soluble or slightly soluble in the body fluids and their harmful ellects are proportional to the toxicity ot tile compounds Inrun d. I.ead. mercury, and arsenic are examples of poisonous dust. Other dusts- exert then harmful c ite d ' locally on the skin and mucous membranes and through irritation to the respiratory pa- axes. Chronic acid and alkalies are examples. Attention recently has been railed to tin: probably harmful clfed of dusts arising from radio-active ores. A fourth groin) of dusts which are insoluble or very difficultly soluble in the body fluids may initiate harmful pathological lung conditions. These may he subdivided into non-lihrosis and lilu osis producing dusts. , The organic dusts, mainly the vegetable libers, such as cotton, jute, hemp, etc., arc non-librosis producing dusts. The fibrosis producing dusts arc limited, so far as we have evidence, to a few of the inorganic mineral dusts, such as free silica, crystalline silicon, quartz. and certain combined silicates. Of the fibrosis producing dusts, those having a high percentage of tree silica are admittedly the most important l>ccaiisr exposure over a period of years to sitcli dusts distinctly predisposes the individual to tuberculosis. The effectiveness of dust control measures in preventing diseases produced Ijy iInsts rail lie determined only by careful physical examination of the workers so exposed under the guidance of competent medical supervision. The benefits wliii b accrue to the employer and employee, alike, as a result of the physical exaniinatii m of all applicants for employment, as well as periodical examination of those already engaged, would indicate very careful consideration by industry of a program fur control of sickness. Such a procedure protects the employer from engaging an applicant already physically or mentally impaired who later may claim d'-al'dit' for a condition either not associated with employment or contracted dining a pre vious employment. The applicant's physical and mental condition is cstahli-hod and by keeping record of his .subsequent illnesses and accidents, the question of re sponsibility for injuries and sickness need never arise. The applicant is protected from engaging iit work tor which he is jiliysicaUv ill adapted which, if undertaken, might easily bring about serious impairment e i bis health. For example, an applicant with an arrested lithrrcu!osj.s who sci work in a certain dusty occupation, if allowed to engage in such work might readily convert ail inactive tuberculosis into an active 011c: thereby endangering life nr at least seriously impairing the applicant's future efficiency and earning rapacity. Whereas the same applicant if assigned to a position that involves no mcli e x posure, might lie expected to continue for years as a useful and productive work man. The examination of applicants for employment likewise protects those that are already employed from the risks of couinmiiieahh: diseases such as tuberculosis and various acute respiratory and other infections being introduced into their midst by a new applicant. Many of the younger individuals who seek employment haw never before re reived a thorough physical examination and consequently are unaware of the de fects from which they suffer. As a result of physical examination-, many defects are located which may he removed or corrected liefore they haw cau-ed iirvparaMi damage, thereby increasing- the ellieiencv of the worker and often averting definite and finally chronic diseases. Furthermore, incipient luhereulo-i-. nn-u-pwtrd dis eases of the heart, kidneys, and a host of other diseases of a similar nature, are discovered and the applicant referred for proper medical care and treatment which otherwise might have been positioned until too late. Of even more importance than the initial physical examination of applicants is the periodic examination and care of old employees by an indu-lry. Such a pro cedure serves to check the cflieicncy of preventive measures designed to prevent occupational diseases. It offers the most effective wav of ronlrohing the health of .30 Tw il lv - thi nl .'inuntil Stifrlv toniirt'ss-- A'tiluntil Saft'ly Couuril large groups of workers liy discovcring early not only occupational (senses, but ninny oilier conditions that go umliseovcred until llie worker is acutely ill or hc- coiues disabled. if the various contagious conditions go unrecognized others be come infected, therein- causing serious economic loss, as well as endangering the health of a group of individuals. The information obtained in mi physical examinations affords the medical super visor the opportunity to make certain that employees are engaged in suitable work out of which they arc getting maximum results, to correct the cHeels ot undue ex posure to harmful environmental conditions, and generally to lessen all occupa tional hazards. As a public health measure, it is impossible to over-estimate the value of periodic examinations in establishing interest in sickness prevention. The set-up of a proper program for medical control of workers exposed to dust depends upon the number of employers involved and individual plant conditions. A series oi articles under the title, of ``The Medical Department Manual" by Dr. Hart I-.. Fisher, appearing in current numbers of "Industrial Medicine." gives a com prehensive account of the organization and operation of a medical department. 1. The establishment of a medical department with adequate facilities and med ical personnel who have qualified in the. field of industrial medicine. A process analysis of all operations in the plant should he made and the medical supervisor should list all possible health hazards and familiarize himself with their physio logical effects. If necessary, he should conduct research studies to determine the harmful effects of new substances introduced into plant, processes about which little is known. In cooperation with other departments, lie should investigate the extent of the hazards ami devise measures of control. 2. The routine examination of all applicants for employment. The procedure should include a detailed history of the applicant's previous illnesses and accidents classified under fa) diseases of childhood. (ID general infectious diseases, fci respiratory diseases, fill venereal diseases, and (V) accidents and resulting physical defects. A detailed history of previous occupations engaged in is very important. A mere .statement of the type of industry in which the applicant was engaged has slight tnlue. if any. The exact duties perionned in each occupation should he noted and information aseerlained as to the probable length of exposure to hazard ous substances. Alter the history lias been taken amt a photograph for identifica tion purposes til part of roiilimD is made, theapplicant should he directed to tiie examining room where he is instructed to remove his clothing for physical exam ination. This examination should he made as complete as is considered necessary to determine the applicant's physical condition. If the applicant has been or will he exposed to dusts which induce lung dis eases. an X-ray picture of the chest is an important part of the examination. This part ot the examination mav he referred to an experienced veemecnelneist. as the value of lids method of diagnosis depends upon the type of pictures i.-iken and the experience --i the reader wlm interprets them. The examining physician aisn may need additional inforinalion obtained In- laboratory aualy-. oi the blood, simtum. and the urine. These aids to diagnosis should he provided or made avail able when desirable. a. The rating and plaremeiit of applicants. Tn cooperation with the personnel department, the applicant should he rated ami placed, not only on his raining and last experiences, hut also mi his physical and mental ahililies to fill vacancies occur ring from lime to lime. The record of hi; physical-and mental examination should he the rotifidentiid property of the medical department. 4. Periodical physical examinations. The frequency of periodical examinations necessarily must depend upon individual circumstances according to the need for such examinalinns as determined hv the supervising phvsician. Where physical examinations are made for the first lime, the employees of long standing should he given ample explanation of the benefit; of such examinations and he given assur ances that their jobs are secure. a. Prnvis'oit for the disabled. Kmfdoyecs who develop disabilities during the course of emplovment should he re-assigned to orcupalimis which will not interfere with or aggravate the disability, or they should lie provided for in other ways. i T^rnty-thinl Annual Safely Coin/rcss-- National Safety Council The Dust Hazards in Industry By DR. R. R. S A Y E R S Medical Officer in Charge, Office of Industrial H ygien e and Sanitation, United States Public Health Service, W ashington, D. C. lie .speaker said in part: Realizing the importance of the dust problem in -try. the I'uited States I'tihlie Health Service in cooperation with the Bureau fines began its first study of the health of workers in dusty trades in 1614, te mines of Joplin, Missouri; ami later, in 1623. the Public Health Service united a series ol dust studies. These later studies were all conducted in the manner in order to permit as detailed a comparison as possible between the 'cut investigations. riefly, these methods of study may he divided as follows: (1) examination to mine the general physical condition of the workers under observation; (2 ) ll physical examination to determine the prevalence of specific diseases of the atorv system and the lung pathology resulting from exposure to the particular hazard; (.5) record of the nature and severity of the disabling illnesses; (4) sis and detailed study of the occupational environment; (5) occupational lity statistics relating to the specific-dust; and (6) autopsies, ic first >ix intensive investigations carried out by the Service dealt with the of workers exposed. I" dusts in a cement plant, granite cutting industry, tcite and bituminous coal mining, silverware maniifacturiug plant, cotton cloth acturing, and in municipal street sweeping. Brief studies were later conducted tain slate, granite, marble and talc ipiarries, while more recently a rather ivc study of the health of anthracite coal miners was completed, esc six-dust studies showed that the workers in the granite cutting plants ere e x p o s e d to the highest dust concentrations were found to suffer from an of pulmonary tuberculosis after 15 years or more of exposure and developed s . front 2 to Id years. In the group exposed to a lesser amount of dust, s developed only after prolonged exposure, with no excess of tuberculosis, found that a close relationship existed between the degree of dust exposure e extent and severity of the pulmonary damage. Anthracite coal miners 1 from dyspnoea and other signs of pneumoconiosis and experienced a high respiratory sickness; in addition, an excessive mortality from influenzania and possibly tuberculosis .was found. Bituminous coal miners experii generalized fibrosis of the lungs and an excess mortality from influenza tunoitia. Cement workers showed some signs of early pneumoconiosis with ss of diseases of the upper respiratory tract. On the other hand, workers jttoii cloth and silverware manufacturing plants and municipal street sweepers gativc for respiratory conditions and other illnesses when compared with ral industrial population. Dritliu//- For five years, the United States Bureau of Mines studied lead miners in the Tri-State District, Oklahoma. The ore here is high in free If the 7.722 men examined, a group of 1,647, or 21.3 per cent, was definitely 1 as having silicosis, not including those diagnosed as having tuberculosis, men diagnosed as having first-stage silicosis had worked an average of . hut Ihove men -tarting in the mines after -411 years of age worked an of r.nly S years. vork of rock drilling in subway and tunnel construction in New York i some respects similar to that of some of the activities in the hard rock- least in so far as the maimer in which dust is evolved, the type of the resultant hazard. Recently the result of a study of rock drillers, mil excavators was reported by the New York Tuberculosis and Health m. An examination of 208 rock drillers. Masters and excavators showed or 57 per1cent of the men had silicosis in various stages of progression, mre of most of these men (75 per cent ) had been for 2(1 years or more. ;-/iy. No study of the health of sandblasters has been reported in the ates; however, a study of the dust exposure of sandblasters was recently by the United Slates Public Health Service in cooperation with the Otturrv Section National Safety Council. Tins investigation indicated that, judged hv the nature of the dust and dearer of the exposure, a real hazard exists in this occupation. 'Phis study also brought out the fact that it \< possible to conduct sandblasting with safety. provided properly designed and well inaintaiiied equipment is used. Diufninueenu:c S ilieu Porkers, Most of the data oil silicosis have been Kalhcrcd from studies made both iu industry and experimentally on dusts containim; tree silica in the form of quartz. Such studies have been made in the pranite industry pottery trades, hard r*vk drilling, etc. There are other tree silica minerals in existence that are not crystalline in nature hut of an amorphous composition. In Santa liarhara t'ounty, ( ahioruia. there cxi-ds the largest and purest <liaiHm;uvott\ silica deposit in the world. This substance en>ist> ot about *S." per cent tree silica. Recently an examination was made of 108 workers selected amom; those employed less than 1 year. 1 to 2 years. 2 to 5 years, and more than 5 'ears. All of the workers were Mexican laborers and the examinations consisted of x-ray determinations, social and medical histories, ami clinical examinations of the chests. Ihisl determination's were also made lmi these were not reported. The outstanding nature revealed by the examination was the splendid physical condition of the men. Kiyhty-four per cent of the workers were reported in excellent physical condition. It was fvmnd that b0 men showed situis of early pneumoconiosis: 15 were in the moderately advanced stnjtc ami 0 in the advanced static. TItis latter findim* was amoii! workers with a history of exposure of more than 5 years. Past Uncord in the (inutile (Jtnnry Industry. It Is a common belief that yranite qnnrryiin* is not so dangerous an industry as granite cutting in enclosed sheds; quarry work is done outdoors and hence may not he attended with very much du<t exposure. However, certain quarry operations require the use of pneumatic tools, which are usually associated with the formation of considerable quantities of dust. It was thought that a study made in a representative ranito quarry mieht ca-t some li.eht on our problem. Accordingly. a study of a clinicradiographic nature of 6a quarriers was made and occupational dust expoMircs were ah obtain}. The hot detenninatious show that marly 58 per ccnt%oi the workers (drillers') were rxpn>cd tr* many times the amount of <lust considered safe at the present time. Drillers were the only persons showing pathologic lunj* chances. Half of these workers with an exposure of 5 to lb years had silicosis, ami -I uf the 5 mm with more than 20 years of such trade life showed this condition. This study sueeeMs that quarry drillers may experience as hieh a death rate fnm pulmonary tuberculosis as do pnenmatic-iool workers in jirauitc cuttinir sheds. / : ,7c7 i/ Intuited M m ide Dust. The pulmonary lihrotic changes dm- to the inhalation of marble dust appear to be slight iu comparison with those caused by stone duM containinj: a Inch percentage of silica iu the form of quartz. A recent study made by us amonir marble workers showed that although marble dust, when inhaled in concentrations avcratiine about 25 million particles per cubic foot of air. produced a mild bilateral, linear fibrosis in a certain number of the NO men examined, m* serious lunj* changes were noted and there was di>alilitv due to .the dii-t. even after many years of exposure I more than *10 years iu some c a se s). Tin* marble du-t under consideration consisted of (,S per cent calcitc and 2 per cent dolemitc. with im silica present. hist Uncord in .I b n i s k r Industry. Artificial abrasives arc widclv Used in indu trv and for this reason the cflcct of the inhalation of du>U produced in the tiKinm'.ii'Mirc or preparation of these products is oi pieal importance. In 1(,25. lnjq and a:.\iin iu l*'51. Dr. Clark of the Norton t'emp.mv at Worcester. Mass., made mvcstie.Umns of workers exposed (o aluminium oxide and silicon carbide dust produce! iu the manufacture of yrimlin^ wheels, which showed that during a jM-riod of 15 years there were proportionately twice as many cases of pulumnary tuber culosis amoii;: those working iu the abrasive thi^l departments as in departments where no abra-ivc dust occurred. In 1951. k e " l e r , ot New jersey, reported the occurrence ot ver luO cases ol allege! silico^i-. in the abrasive powder imlustrv. in whit'h the dust consisted f 9b j>e r cent tree sdica. /: \ y><\w e t,i Silietite /hist. It has luvn the h l i e i that the inhalation f diuls c.on|M'l t silicates fcombine! silica), iu comparison with silica (free silica in th form .*f tput t / ) . was innocuous. Of icceut years many in\a >ti^at*rs have heeomc toiiui/ant <*f the hazards.m silicate hist exposure. Adiestosis. a fdr<sis 2 I'wiily-thinl Annual Sajely ( ont/irsx--A'attonal Safely Coinial the lungs caused by the inhalation of asbestos dust, lias already been described l\ in its clinical and roctnei-nogrntihic manifestation!: by imestimators in other intrics, but to date no studies have been reported in the United States. Cement t, which contains about 22 per cent combined silica, lias been studied, and the cts of the inhalation by workers lias been discussed here. In March, 19.13, csseii. of the United States 1'tihlic Health Service, reported the results of a ly conducted among treiuolitc talc and slate workers. The slate dust to which ;c workers were exposal consisted mainly of silicates, there being less than r vent of ipiartz in the dust. T he talc was a hydrous calcium-magnesium silicate, g 45 per cent talc and 45 per cent treiuolitc. with no quart?, present. The ills of the study seemed to indicate a relationship between the amount of dust led and the effect of this dust on the lungs ut workers. itulislienl .SVm/iV.t. Recently, l.anza ami Vane estimated that there are some Kid workers engaged in the minim;, quarrying and manufacturing industries his country in which air exposure to silica dust to a harmful decree is eitd. Their analysis of mortality experience of twelve life insurance companies the period 19)5-1926 showed that the actual mortality from respiratory tuberis among the silica expo-cd persons was alnmt three times that of a noni dust croup. It one considers- their data for certain occupations in metal s and granite ami sandstone quarries, occupations known to he exposed to concentrations of hazardous dusts, then the comparison is more striking, since ictnal deaths among these workers was found to lie ten times that of the e.xd deaths. More detailed statistics on occupational mortality as reported hv the .lrar-Gcttcr.'il of Kngland and Wales (1921-1923), and summarized by llrittcn. the high rate of l.fiSti per KKl.OflO fur tin and copper miners, while the rate all occupied and retired males" was only 150. Other occupations with silica lire showed an excess. tun the evidence just presented concerning the injurious effects produced by ihalatimi of certain dusts, it is apparent that a knowledge of the properties given du-t which determine its capacity to produce pulmonary pathology is ial. Numerous investigations of the industrial dust problem indicate that propel tie- are the chemical and mincralogical composition of the dust, its itratioti in the imliMria! atmosphere, .and its particle size, alt earlier portion of this discussion evidence was presented which indicated dose relation existed between morbidity and mortality rates front various itorv diseases and the exposure to certain dusts in industry. In the study dust hazard in the granite cutting industry, it was definitely proved that is a direct relation between the magnitude of the dust exposure and sickness rath resulting from tuberculosis. It is quite evident, as a result of these . that the remedy of the dust evil lies in the effective removal or suppression dust to concentration considered safe. However, no set rules may lie cstahfor the mechanical protection to he instituted in an attempt to control indusust. Specific conditions encountered in a plant will determine the type of ion to he employed. protection of workers against certain dusts known to lie toxic may at ie accomplished by the substitution of a lion-toxic material for the toxic one. :nmple of such a procedure is the possible use of a metallic or other type icial abrasive for sand in the sandblasting process in those operations in it is not essential to use sand, a substance high in quartz content. Again, ebatiical enclosure of the dust-creating process also serves to protect the An excellent illustration of this type of protection is afforded by the sandblast barrel used in the cleaning of small objects. Sometimes it is to protect the worker by the substitution of wet for dry processes, as wet instead of dry. In one instance, in the granite cutting study t previously ed. an operator using a diamond point tool worked the stone wet; the : dust amounted to 22 million particles per cubic foot. The same operator n r>quested to work the stone dry; a> a result, the amount of dust rcacbed i figure of 45 million particles per cubic foot. In the weaving nt asbestos has been possible to reduce the amoiml of dust in the air by wet weaving nrth of the amount present win n the process is conducted hv dry methods., example (d this procedure in allaying dust is the use of a spray of water OII../TV . ut l ht h in leyuer ami jack-hammer drilling in hard rock. although the new type of K?l|\ duM trap is now tmdiug imidt favor for ilis kind of work. I he Kelly trap consists of a metal chamber designed to enclose the drill steel * at the rock surface. N o attempt is made to secure a mechanical seal with the rock or between the trap and the drill Meek l he dust is removed hy an air stream and is earned into an exhaust system connected to the trap. Kscape u| dust particles through openings between the uneven rock surfaces and the trap is prevented by the air seal produced by the billowing air. Tests made on this trap under actual working conditions show that the dust concentration at the worker's breathing zone may be kept down to less than 10 million particles per cubic loot with a h() cubic foot per minute rate of air (low through the hood. 'Hus trap is a step forward in the program **t duM remov'd; however, in underground work, stub as in mines ami subways, there is still the need to solve the problem of compact dust disposal equipment. In certain cases, such as in .the sandblasting of large castings in sandblast rooms, the practical safeguard to the worker is to provide him with a mask or helmet of the positive air pressure type. In the sandblast investigation previously men tioned. it was found that when from 5 to 6 cubic feel of practically dust-free air per minute are supplied to the helmet, the worker receives ideal protection. H o w ever, one ntitM always bear in mind that the ultimate criterion oi protection should he the dust determination of the air within the helmet during blasting anil not the tjuantily of the air supply itself. In most dusty processes, however, the most effective means of dust elimination are by the use of properly designed exhaust ventilation systems. Since in many instances it is difficult, costly, ami at times an unnecessary procedure to remove all the dust in the vicinity of a worker, we need first to determine the minimum amount of a certain* dust which the worker can apparently tolerate with impunity. Such miormation can he made .'nailable by the type of studies carried out by the l 'uhlic Health Service. l:or example, in the granite study already referred to, it duM at the breathing level of about HI millin particles per cubic toot (35 per cent free silica). Studies of 'dust removal devices Used in granite cutting plants at the time this work was conducted showed that a linear velocity of 1.5ni) feet per minute aiiif.isiirnl by an anemometer at the fare of the duM-removal hood, would keep the duM at the breathing level to an amount less than III million particles per cubic foot A word should be said concerning personal respiratory protection agriuM dusts. It has already been shown that in the tise of positive pressure respiratory devices in sandblast me. it is important to have a well -designed device supplied with about h cubic feel of duM-irec air per minute to give full protection to the worker. With reference l respirators-of the filter type, there is still much to be accomplished in the design of an efficient ami comfortable mask' for continuous ` use. Of great value arc standard methods for the testing of the ef/icieney of respiratory pro tection devices. JJrinker advocates teMing a device against the particular duM which the respirator is to encounter, these tests to he made both in the lahnrap *r> and under actual industrial conditions. He further suggested that -omc impartial agency should conduct such teM> and certify the devices ior imtiistrial u>e. the work being done on a cost basis. The U. >. Jhu'cau of Mines lias prepared such a schedule lor to tin g and approving' respirators. 1 wish to stress the importance oi good housekeeping in the et'iort 1. combat the dust hazard, (ood housekeeping >botdd not only imply the removal of accuumlalid duM about a workroom bin should also embrace efficient maintenance dust removal devices and respiratory protective equipment. Systematic in-pceh'-i of all duM suppression equipment should In* an axiomatic princinle in e u r e i11:-1y industry rather than the casual attention which it now receives in many instance*. Report of the Nominating Committee 'l lie chairman called inr the report ni die Nominatin'*: ( iinmittee at this point, ami new oifieiT-* for the set {ion to seive during the ensuing year were ii.iimiiand and t levied as |u|l.>w s :