Document da1YeMb47Rxykp7zr0O6bV0kq

FILE NAME: National Safety Council (NSC) DATE: 1934 Oct DOC#: NSC162 DOCUMENT DESCRIPTION: NSC Transactions 1934 TRANSACTIONS National Safety Council Incorporated TWENTY-THIRD ANNUAL SAFETY CONGRESS Cleveland, Ohio October I to October 5, 1934 The Cleveland, Carter and Statler Hotels Copyright, 1935, National Safety Gouncil, his. Publication Plan T H E TRA N SA C T IO N S of the Twenty-third Annual Safety Con gress, National Safety Council, 1934, are 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 Highway 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 on request by other |CounciI members. For the benefit of many members who have found it advantageous to distribute copies of these T R A N SA C TIO 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 kach. T H E P L A N O F P U B L IC A T IO 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. NATIONAL SAFETY COUNCIL, INC. 20 North Wacker Drive, Chicago CONTENTS PAGE Council Officers and D irectors....................................................................... 4 Council Purposes and Policies..................................................................... .............. - 9 Annual Meeting of M em bers.......................................................................................... 11 Annual Banquet ................................................................................................................. 21 Subject Sessions-- Dust in I n d u s tr y ........................................................................................................ 23 Fire Prevention in I n d u s tr y .................. 31 Fusion W elding and C u ttin g .................................................................................. 41 Industrial Nursing ................................................. 45 Industry and Its Motor Vehicle Accident P roble m ....................................... 51 Maintaining Interest in S afety.............................................................................. 59 Mechanical Methods of Handling M aterials................................................... 67 New Workers ............................................................................................................ 73 Poisonous Fumes and V a p o r s .............................................................................. 79 Safety Equipment .................................................................................................... 85 Safety Organization and P r o g r a m ........................................................................ 93 Safe Use of Chemicals in I n d u s tr y ...................................................................... 99 Safe Use of Electricity in I n d u s tr y ...................................................................... 103 The Injured W o r k e r ................................................................................................ 113 W hy People F a l l ....................................................................................................... 121 All Ohio D a y ....................................................................................................................... 127 F E R A Safety Conference.......... ................................................................................... 131 Industrial Safety Lectures-- Selling the Safety I d e a ................... '135 The Psychology of the Safety Movement in Changing Times. . . ............. 140 Accident Prevention Equipment Manufacturers' Section..................................... 149 Aeronautical Section ........................................................................................................ 153 A. S. S. E.--Engineering Section................................................................................ 159 Automotive and Machine Shop Section...................................................................... 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 L eather Industries Section...................................... 245 Metals S e c tio n ................................ ................................................................................... 255 Mining Section .................................. 269 Paper and Pulp Section................................................................................................... 289 Petroleum Section .............................. 307 Power Press Section...................................... 325 Public Utilities Section............................................................... 337 Quarry Section ......................................................................... 349 Refrigeration Section ....................................................................................................... 357 Rubber Section ............................................................................................... 365 Safety Section, A R A --Steam Railroad Section, N S C ........................................... 383 Textile Section . ............................................................................................................... 413 Transit Section ............................................................................................................... 419 Wood Products S e c t io n .. .. ......................................................................................... 435 I n d e x ..................................................................................................................................... 445 National Safety Council Incorporated HONORARY MEMBERS A sm I.ITIIi.N OF Ikon AND STEEL ElFXIKIC.U. Robert W. C ampbell A rthur W h.i.iams KNOINKER OFFICERS (1934-1935) J oh n K. Long, President. Robert 1. Ca t u x , Vice-President for Public Safety. 1). D. F ennell, Vice-President for Public Relations. Lew R. P almer, Vice-President for Safety Councils. A lbert S. R egula, Vice-President for Engineering. C. IN'. S m ith , Vice-President for Industrial Safety. R. T. S olexsten, \'ice-President for Membership. D r. C. H. W atson, Vice-President for (Health. A. W . W hitney, Vice-President for Education. W. E. W orth, Vice-President for Finance and Treasurer. W. II. C ameron, Managing Director and Secretary. EXECUTIVE COMMITTEE (1934-1935) A. L. A rmstrong, Kastman Kodak Company C. B. A i;el, Past President. J. I: B a n a s h , Past President. C. W. B ergcjuist, Past President. F. W. Br au n , Wood Products Section. W. H. Cameron, National Safety Council. R obert W. Campbell. Past President. T. H. Carrow, American Railway Association. R obert I. Catlin , Aetna Casualty & Surety Company. J. E. Culliney , Bethlehem, Steel Company, L ewis A. D f.Blois, Past President. M arcus A. Dow, Past President. D D. F ennell. Consulting Engineer. I). L. F e n n e l l , Kansas City Safety Council. C apt. E. W . F iske, J r., Marine Section. R. B. F ortuin, Lehigh Valley Safety Council. H arry Gu h .bert. The Pullman Company. M erle C. H ale, Automotive & Machine Shop Section. G. T. H fllmuth, Chicago. North Shore & Milwaukee Railroad Co. H on. H arold G. H offman, Street & Highway Traffic Section. T homas P. K earns, Industrial Coimnfssion of Ohio. W alter G. K ing, Past Preside! 4 Officers and Directors F m .nki.in M. Kkk.ml, Evanston Safety (_ouncil. John E. Long, The Delaware & Hudson Railroad Corp. Taos. Id. MacDonald, United Stales Department of Agriculture. K. J. M f.mrfn, Portland Cement Association. 1. W. M illar, Accident Prevention .Manufacturers' Section. H arold I- Mixnt, If. I. duPont de Nemours & Co., Inc. A rthur 'I' Murky, Past President. I.t.w R. P alm Fit, Past President. C. I . Pi ti tno.N't:. Past President. ('. If. Ralston, Western Pennsylvania Safely Council. A i.iii ut S. R kgui.a, Industrial Relations Counselors, Inc. I.t. Cm.. 11. A. Ri:ninc.ir, Past President. ( i|..iiia;1-, If. S.aniorii, fi'eneral Ifletcric Company. Roia ni I.. ^ c 11m ITT, Louisville Safety Council. IIakkv A. Sitiiii.tz, United Slates Steel Corporation. C hari.its 1!. Scott, Past President. I.fstkk D. S lymocr, Aeronautical Section. C. W. S mith, Standard Oil Company fludiana). W.ai.tku Di:nt S mith. Delaware Safctv Council. R. T. Solf.NsTKN, Elliott Service Company. Ct.ark\ ck P. T aylor, Massachusetts Safety Council. C. P. Tot.man, Past President, j. A. Voss, Metals Section (ii.oRi.i: II. W arkfl, Union Pacific Railroad Company. D r. C. 11. W a i s o v , American Telephone & Telegraph Company. A. W. WTmtnkv, National Jlurcau of Casualty & Surety Underwriters. W. If. W orth, International Harvester Company. \in lin t II. Young, Past President. DIRECTORS (1934-1935) I'kkiiKrick A rc'iif.r. Child Education Section. Wit.i.iA.u E. A kukux, Safety Div., Milwaukee Association of Commerce. A. 1.. A rmstrong, Eastman Kodak Company. W illiam H. Rakkk, Quarry Section. .1. 1. I'.anasii, Consulting Engineer. 11 D. B.axt.a, Paper & Pulp Section. E rnksi W. P>f.ck. United States Rubber Products, Inc. W. A. Bfnxftt, Worcester Safety Council. C. W. Bfkoouist, Wi'stern Electric. Company. D \ , m S. P.fvfr, Liberty Mutual Insurance Company. If. b. Blank, Jones & Laughlin Steel Corp. C I'. Borkfnhagkn, Kenosha Safety Connie!. L. W. Braun, Wood Products Section. i oi.. Pn ii. H. Brockman, St. Louis Safety Council. I'rfston 1). Cali.hm, Baltimore Safety Council. W. 11. Cami-.rox. Kational Safety Council. T. .1. Carvin', Chic.ago Safetv Council. T. 11. Carkow, American Railway A smiciation. 6 Twenty-third Annual Safety Congress--National Safety Council R obert I. Catlin, Aetna Casualty & Surety Co. Carl C. Clements, Refrigeration Section. Roscok D. Conlin, Rahway Safety Council. H. H erbert Corson, Safety Dept., Nashville Chamber of Commerce. J. E. Culliney, Bethlehem Steel Company. E dward D ana , Boston Elevated Railway. E. A. D avidson, Consulting Engineer. R ichard H. D avis, Blackstone Valley Safety Council C harles D. D awson, Grand Rapids Safety Council. Lewis A. D f.Blois, Consulting Engineer. J ay E. D ecker, Mason City Safety Council.. J ames B. D ouglas, The Philadelphia Gas Works Company. Louis I. D ublin, Metropolitan Life Insurance Company. C harles H. E ames, Textile Section. D. D. F ennell, Consulting Engineer. D. L. F ennell, Kansas City Safety Council. D onald A. F inkbeiner, Toledo Safety Council. Cart. E. W. F iske, Jr., Marine Section., Howard B. F onda, Burroughs Wellcome; & Co. (U. S. A.) Inc. R. B F ortuin, Lehigh Valley Safety Council. E. N. Goldstine, Construction Section, f Otiio M. Graves, The General Crushed Stone Co. H arry G uilbert, The Pullman Company. I saiah IIai.e, The Atchison, Topeka &' Santa Fe Railway Co. M kri.e C. H ale, Automotive & Machine Shop Section. M a.tor B olling H. H andy, Richmond Safety Council. D. T. H arrington, United States Bureau of Mines. G. T. H f.i.lm u th, Chicagofi North Shore & Milwaukee R. R. Co. Ciias. E. H ill, New York Central Lines. 1Ion. H arold G. H offman, Street & Highway Traffic Section. Ci.audf. J. H olding, Albany Safety Council. J ulius W. PIorre. Hudson County Safety Council. H arry D. I mmei., Pennsylvania Dept, of Labor & Industry. L ex Jen sen , Berkeley Traffic Safety Commission. E dgar P. K aiile, York County Safety Council. T homas P. K earns, Industrial Commission of Ohio. K. T. ICf.llf.r, Detroit Industrial Safety Council. Ira V. K eener, Pennsylvania Salt Manufacturing Co. E. J. K reh, Public Utilities Section. F ranklin M. K reml, Evanston Safety Council. C. L. L aF ountaink, Great Northern Railway Co. F rank J. L a n a iia n , Fort Pitt Malleable Iron Co. John L aukrman, Meat Packing, Tanning & Leather Industries Section. S imon L azarus, Safety Council, Columbus ("Ohiol Chamber of Commerce. Joseph L ii.i.tch, Rochester Safety Council. Du. R. M. Little, New York Department of Education. G. O. L ockwood, Petroleum Section. J. F.._ Long, The Delaware & Hudson Railroad Corp. W. K. Loyd, Safety Div., Birmingham Chamber of Commerce. Officers and Directors 7 A. E. Lundsteadt, De livery, Taxicab & Pus Section. Tnos. H. M acD onald, United States Department of Agriculture. L, T. McA rthur, l 'eoria Safety Council. i M iller McClintock, H arvard University. T. if. McKknney, Illinois Steel Company, South Works. A. D. McW iiortf.h, Safety Div., Memphis Chamber of Commerce. H. T. M artin, Fisk Rubber Company. J. O. M artin, Employees' Publication Section. F. W. M atson, Minnesota Safety Council. E. J. M eijrkn, Portland Cement Association. T. O. Meisneu, Tower Press Section. W m. G. Mf.tzcer, Mining Section. I. W. M illard, Accident Prevention Equipment Manufacturers' Section. H arold L. M iner, E. I. duPont de Nemours & Co., Inc. H enry J. M ixeur, Elizabeth Safety Council. Lawrence M. M oore, Eastbay Safety Council. R. 15. Morley, Industrial Accident Prevention Associations. John A. Oartel, Carnegie Steel Company, George C. A. Oi*r, The Detroit Edison Company. Lew R. P almer, Equitable Life Assurance Society. John C. P arker, Ilrooklyn Safety Council. D avid A. P atton, Newark Safety Council. C. E. F kttiuone, American Mutual Liability Insurance Company. Gf.n . Georc.e 15. P illsuury, W a r Department. J. P. P ower, Seattle Traffic & Safety Council. (.'. E. R a lston. Western Pennsylvania Safety' Council. Albert S. R gula, Industrial Relations Counselors, Inc. Lt. Col. H enry A. R enixger, Lehigh Portland Cement Company. Marines R iter, Paterson Safety Council. G. E. S anford, General Eletcric Company. H enry G. S ciiaffner, Erie Safety Council. T. A. Schexdki., Food Section. Rorkrt L. S chmitt, Louisville Safety Council. 11. V. Sen rei her, Transit Section. H arry A. S chultz. United Slates Steel Corporation. Charles 15. Scott, Pureau of Safely, Inc. L ester 1). S eymour, Aeronautical Section. F ari. S. S iiartz. er, Utica Safety Council. Ray II. S heets, Madison County Safety Council. D r. L. A. S iioudy, Bethlehem Steel Company. Ernest L. S imonds, New Haven Safety Council. Lee E. S kkel, Cleveland Safety Council. C. W. S mith, Standard Oil Company (Indiana). W alter D ent S m it h , Delaware Safety Council. R. T. S oi.ensten, Elliott Service Company. K. C. S pring, Lansdalc, Pa. Giorgi; k. S tephens, Safety Pureau, Buffalo Chamber of Commerce. Lucius S. Storks, United Railways & Electric Co. 8 Twenty-third Annua! Safely Com/rcss--National Safely (. amici! D r. F. M. S ui.zm ax, Troy Safely Council. A lfred H. S wayne, General Motors Corporation. Clarexce P. Taylor, Massachusetts Safety Council. A rthur M. Tout:. Consulting Marine Engineer. 'V T r k c | i. Schenectady Safety Council. ^ ^ urrbvlle, San Antonio Safety Council. .1. A. Voss, Metals Section. H. A. W alker, Rubber Section. George H. W arfel, Union Pacific Railroad Company. Dr. CASsrus H. W atson-, American Telephone & Telegraph H arry M. W ebber, Illinois Hell Telephone Company. A lbert C. WJhite, J r., Springfield Safety Council. S. E. W iiitinx, Liberty Mutual Insurance Company. Company. ' w ' ,\YmTXEY'TNatio,,al Bllreau "i Casualty & Surety Underwriters U. H. W ixaxs. Union Carbide & Carbon Corp. D r. C ,E . A. WYnslow, Yale Medical School. ' H arry W ise. S r., Chattanooga Safety Council. J.^M. W oltz, Youngstown Sheet & Tube Company. Wr. E. W orth, International Harvester Company. E. J. Zauft. Safety Bureau, Duluth Chamber of Commerce Earl W. Zimmerman-, Safety Die., Syracuse Chamber of Commerce. J. b. ook, Cement Section. m iciL ' , :'ll to Alt i ouncil reaors of ti.e to lay Lieii developed ''I action in 'I'ogram for 'legates and i from the 27, 1934 . in session igs and my it you are program to . adv taken h, because ! with the e solution citizens is -'tig toll of grim that hway coin sure, and ad disaster, mend your . .ion with upon our ..LT. Hoffman, Kistmaslcr. is. of New surpassed, America.' ilar mono- evening: me Council T IV L X T Y - T J I I RU AN XU X L S A W TV (.'ONURLSS N ATIO N AL SA V LTY COUNCIL Dust in Industry . FRIDAY AFTERNOON SESSION . October 5, 1934 The session devoted to a discussion of Dust in Industry was called to order by Dr. E. G. Alciter, Director, Industrial Hygiene Laboratory, Employers Mutual Lia bility Insurance Co., Milwaukee, who presided. Dr. Meiter bricHv welcomed the delegates and then introduced the first speaker. ' Types of Dust That Cause Occupational Diseases By LEROY U. GARDNER, M.D. Director, Saranac Laboratory for the Study of Tuberculosis, of the Edward L. Trudeau Foundation, Saranac Lake, N. Y. Hie speaker said in p a rt: Experience has demonstrated that the lung pssucs can tolern'e very large amounts of most kinds of foreign dust particles without serious interference with function. The lung may be intensely pigmented by colored dusts with no evidence that respiration is impaired. But dusts composed, in whole or in part, of silica have been shown to be dangerous because they 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 ami it thickens the delicate membranes so that a free interchange ot gasses is impeded. Fortunately, these results only follow the prolonged inhalation of very large quantities of silica. Experiments have demonstrated that the injection,of silica into the tissues ot annuals kills the cell" where the substance lodges and excites an infiamm -1>-n M hen healing takes place a very dense and characteristic kind of scar tissue forms. Most non-siliccous dusts produce no inflammation and very little scar. It lias been shown that such changes do not follow the injection of silica unless the particles are very fine, three microns or less in diameter, and unless enough of them localize in one area. With larger particles the rate 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. T he reaction to fine silica begins within four or five hours and it continues for a period of years. If the silica is combined with bases in the form of silicates, it rarely produces such active and _progressive changes. Tile silicate of magnesium, asbestos, does cause the formation of scar tissue in experimental animals and in the human lung, but most other silicates are not generally recognized as Irritating. Recentlv it has been claimed that a hydrated silicate of aluminum and potassium, called sericite, is responsible for most of the cases of silicosis. This silicate, a transformed feldspar.' is often associated with tpiartz and it has been identified in the lungs of persons suf- 23 f :S ;! O'; gW&pN ?"ci ' A c -Ic: -'.fMt:,' r A 'D 24 7 wcnty-lliinl Annual .Sajcly Conyrcs.s--National Saj'clx Council SnlficinT"-hn!i^iS' , H WCVcr' a t .lcast `VO `n>cs of soheito have failed to excite 'ip1 ''LS wll.c," '"Jectod into animals. Experiments with this substance , sh l progiess. Kaolin, an alunnno-silicate of potash, lias also produced quite characteristic changes in the lungs of rabbits lint our >resent l- t i not permit us to assume that, s i l i c a s as a c i ^ i wii'^produc u^ ^ d L ^ T Most observers now behevc that uncombined silica, or f|u a rt/ is poiso o s to he tissues because it is slowly dissolved in the fluids of the body Ccrn v the soluhih ty were. t l ^ < V ^ n ^ r t - p l d rnimsmmmmm n ^ r lT T Z V S ft mLhanically'^The " ?Ci quartz particles were believed lo abraid the 1 ng ^ * 1 excite t l forma1' smne imrecocimccl property possibly relateil to its atomic structure ' ' ,,A!Sc3V l , C S of" *S s i r SE s f t i f . T ^ S T i" E ; :: S lhagocjtes that ingest too manv < quartz i ^ ~ particles ' S S ,J!rj s are Hlleel In- tic % z accumulate so that many of'lheni mgest^onlvT few `nrticlc?*' *',llilcr.oc>-tcs s iare consequently localized in die norlcs. ` f S W s ^ * .. r cf,nsK,l`ral,lc m,mbcrs particles gr(, w ^ M Si L (hhn;ustelen"n,st in l l l e ^ 's t r u c n ^ "`'' n t T T ' a m a rtel ' CI" to such an extent that the n o d e V e ih r e K r e p la c e d , w o f ' ti.s>ue fibres, niton several times as lar^e as the ori-nml t1fIri,, c* ^ scar croacli upon and compress the lymphatic vessels Thf lV ' - ucn nodules on , fhesc preliminary changes do not constitute the disease silicosis- d - llr,,i,., only the ymphatic system.. The respiratory tissues a r e no, a p p ^ h . K ! ' a iVmoH xu ^nud styio A-ia\ iiims these preliminary chanties mav hr visinli/ .,i u V." enmg and heading of the shadows cast bv the blood vcss'el toeetli 1 i1'' a ing of the shadow of the. root of the lung. Hie h i l l " o iel ire tl id'e! ' r , " "TM' the most important lymphatic vessels course through their wills Tbe I r CaUS-e hose locations the .silica again stimulates the formation of scar tissue r is a 's a r /^ r f* i i T T ' r l TV L * -8 2 With the tormat.on of silicotic nodules in the functioning parts of the lung the Coit iic 'ailed to excite this substance produced quite mowledge doestissue damage. ' 1 poisonous to Certainly the hut it is difti;uartz could he animation. If response alter ihe case. For te hard sharp ite the forma1 longer tenable ainond. carho . no formation -ilica is due to cts which arc Vhavior of the nodules of scar infection, espe- this irritating !,,w phagocytes :gh phagocytes r such circtimles the motility lymphatic vese rapid under !s of panicles marked overiction develops -e. glassy scar ' nodules tu rn of the lung lly diminished, t'ssue develop : they involve ably affected. t as a tliickwith a. widi'iikcued because 1nc heading is les within the in the lymph d off through die air spaces, scattered. In The result n throughout with function die air spaces Mate and their is-also incom- thc lung the />nsl in I ml us/rv 25 STMm c f,,s h l l wr ? ' V ', t thl1oy ,n<:rt'!lse >"U',"h"VheXr-raan>d' size thev 'Mblot sout^ the formertlty. accentuated linear shadows ot the blood vessels. In a well marked case both limb slutdotvs*1"' \\V ere 'Ihe?TMdC<1 and Z film lu" ulrc,l-s s,,d ' sh arl>ly defined, rounded, nodular " l" at thc ~ - visible a maie h a r i f t T i s 0 Hn'!iCOSiS '* pr0TrCSsive one ami it continues to develop alter b n v e s \ ?tt f y .ccl,!,;Ul,in- Venous results only follow, however when be hev rm 1 -e"any " Z CV " thc hm* tisse itself. As such nodules increase in size oidv important functional elements. Obviously thc continued growth oi o ............ * .. .. may i r i s ^ t Z , r e s e t , \SdiC f iS itS f.rcl'ue,lt complication by tuberculosis. This a new infecdo f r o m ,T' ? aJ ,1'C',;x 'staut latent infection or it may result from otd silicos s Z e n t r r ' 1 hfC ilan?ef ! -Teases with the amount and it oftenPl'ails to ,V i `'" " T ' mfcct"m ,n lhc dlicotic is usually chronic onset t l , 7 produce characteristic symptoms for months or years' after its groups rff active'r'vorkm *n discovered in routine X-ray animation ,n id l b ! ' ' However, evidences of disability are much more marked slllC0tlc individuals with infection than in those with uncomplicated disease D m >ery aci,te r i,rsc , h e s i b j S r b m S ; tuberculosis is not DertVrtl ^ ^ cailsc oi the susceptibility of the silicotic him? to silira o ? th V Perfectly understood, but it would seem that the action of the si tea on the tissues creates a medium favorable for the growth of the bacteria l ie tubercle baciil, multiply and a slowly progressive tls u e 4 t m n e ^ u ^ b n t ie usual clinical symptoms of tuberculosis are often hold in abcvance for i ' lone mized' i w X 1` s t r u Z l i r a,l,S"rpti'm of I" TM " " Products of infection are' min - cuiosis ensues!' RaU,S " U,,|,lT ha,,d- s-vniPtf>" 's rlcvcl..p and death from tuber- nnbm'nir"1''- 'tIu`r'-typc > dust which is generally recognize,1 as a cause ,,f severe h Z r a c l c "'a'd " ^ p, ',ll,catf < magnesium. This substance is fibrous upper respiratory 5 X 5 ^ 1 * ^ r p r Z . f t K S l i sueli fibres and even quite long ones m a y ' penetrate into t h f i n e r nch,- i X f hese structures have irregularities in their walls which seem to hold the fibre i f ~ r ' s r s s - i x & B rvtps' T1 1 1IS loca!'un thc mshestos particles are surrounded and ingested In pha,,o- fragmeiils directly i n X t h e inX hich 'd iev' He.'"'Th" mSldh'Xu- i1nI1g, iinn ZCOl iiull "Z1lXs.0 htilX10KTMCMlil`t?' Xof uf 'I f (`IlfiHl,isCt c`"(.,noclive tiss,.C` e.Kc_lls, in the walls resultnarrows or .closes the tube and thereby shuts' off X n i Z s ' oi X X Z m o " S liiS f ^ dustTare found i'n thePlymi5, nodes!'*105 a"lL-- T^>*''Rnif.cant amounts of this ^ leL bcrr ! r ^ r s ,T .S r ib e inhalation of unusual amounts of non-siliccous dusts apparently fails to nro- ma\ uI minSatcly bheee!(Hhs,c0o',vScr'c"dS, ' ?hut,U,n,So-ne Rar1e5 rpfmCo0-m"r*s.i',! partides enter the lung and arc ingested"y tha ,,imfoims* nes the 'iuZZ dthleumi iremain uitbmi , fthre ka!ifrd spt nacems T for VaC7lonrga ' )tii<ml,ye. a "S(1om- e, a pacrotnicsuelaqrZlyc oth,o,,se Vconm-- f-i 5.4-;.:* 26 1 ti'cnty-thi) d xlmiiitil Safety Cougrcss--Aa!lonal Safety Council tauiing relatively lew particles, make their way into the lymphatic system and accu mulate m the lymph nodes. In sullieicnt concentration, or perhaps because they are mixed with small amounts of silica, they set up a low grade, uou-progres.sive chronic mt animation. But this reaction results only in a little thickening in the lymph j.odes and about the lymphatic vessels. 1lie lung tissue may he variously pigmented, y.ack from coal or red from iron, hut there is no formation of scar tissue that interleres with junction. I he susceptibility to tuberculosis of the person with such pig mentation is not increased but it is apparently quite definite that pneumonia is unduly prevalent in coal miners and that chronic bronchitis results from the inlialat'OU ot cement. 1he X-ray films of men working in nun-siliceous dusts siiows either notnmg at all or a more or less marked accentuation ot the linear shadows cast by t.,e Ulood vessels, this, of course, is due to the chronic inflammatory changes about the jympnatic trunks m walls of blood vessels. 7 ' ? efl!:ct,s mixtures of free silica and lion-siliceous materials are less clearly uctmed and should receive more serious attention. It would seem unwise to assume, la* Jetm. , e tllc, l'ast' t'lat tl'e 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 accumulating which suggest that at least some other ." ' , matcnally n!0(hl-v the action of quartz, both in its capacity to produce ' , fibrosis m the lungs and to increase the susceptibilitv to tuberculosis For example, animals inhaling heavy concentrations of a mixture of equal parts of pure smWownn' onnoit evmena" t!hfe tlslrlig7hterst Ciingdl!itcaht0ioUnrSofa n(olad-vuleovefrorma atPio^niodin oft1he14luinngo,ntlwishehraevaes I ure quartz dust, inhaled tor only two hours a day..produces definite undulation. It aiso sceins to be true tli.-it animals inhaling such a mixture are much less susceptible to timercuiosis than those exposed to pure quartz. In the case of the human iron miner, some lungs show definite silicotic nodulation, others onlv a verv few' nodules r e ' 'n h r lly " '10tUl f at al1' AU exhibit heavy deposits of iron particles with a v`.`l a connective tissue reaction. When these imdings can be correlated with ,.'qmpCafi analys.,s 01 .,he lung tissues and the approximate amount of rock work ...ncn t.icse miners have performed, some relationship between the exposure to smea and the librous nodule formation may be established. Tul.crculos.s in these ir,Si miners is apparently less prevalent and much less severe than in men exposed w ri'i-ers ! ! ? ' V 'aS f 1'1-' Sa,(1 irr,n In,uors ls als,) probablv true of foun.lrr n v ^ l e i / ' ' ' ' '' o ' h | ,s "cneraiiy accepted that ,,,c,, in the latter occupation .are css t merculosis than the average lor the age period; Cummins believes that ,.e have the injection but that it ,s so atypical and benign in its manifestations tnat it escapes diagnosis. Mention should also be made of mixed dusts like certain slates and granite cr.naming large amounts of tree silica m combination with silicates. Experimemallv mese su stances _behave atypically and do not produce nodular fibrosis ,,,,less there is complicating infection. The same may also be true in human beings Unques tionably such dusts arc capable of producing typical silicotic nodules and ti ev nre- . ' '-s.c.s.i .'iain11um ti. m i i M iu u u i r r i 'r i v o n m e n iimre intensive study to clarity our views on the whole subject. At the present time it .appears that the action of their quartz component is modified and paniailv neu tralized by the other substances which they contain. ' Using Exhaust Systems and Respiratory Equipment To Protect Workers Exposed to Dust By STUART W. GURNEY and DAVID S. BEYER Liberty Mutual Insurance Company, Boston The speaker said m p a r t: A number of our states have had references to dust elimination m their ,abor laws for a good many years, but no state lias as yet thoroughly enforced these laws. The codes of five states which we investigated provide that grinding, buffing and polishing wheels should be exhausted, although two ot the states exempt Irom these provisions wheels on which water is used. 2b 1 li'cnly-third slnnual Safety Congress--National Safety Council '..lining relatively few particles, make their way into the lymphatic system and accu mulate in the lymph nodes. In Mit'ficient cunrentrati'm, or perhaps because they are mixed with small amounts of silica, they set up a low grade, non-progressive chronic mtlammation. Hut this reaction result-' only in a little thickening in the lymph nodes and about the lymphatic vessels. The lung tissue may he variously pigmented, ''lack from coal or reel from iron, hut there is no formation of scar tissue that inter feres with function. The susceptibility to tuberculosis of the person with such pig mentation is nut increased but it is apparently quite definite that pneumonia is unduly prevalent in coal miners and that chronic bronchitis results from the inhala tion of cement. The X-ray films of men working in non-siliceoiis dusts shows cither imiliing at all or a more or less marked accentuation of the linear shadows cast by the Mood vessels. This, of course, is flue to the chronic inlkimniatory changes about the lymphatic trunks in nails of Mo</d Vc^.-cJs. The effects of mixtures of free silica and imn-siliccous 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 the 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 arc accumulating which suggest that at least some other dusts may materially modify the action of quartz, both in its capacity to produce nodular fibrosis in the lungs and to increa>e the susceptibility to tuberculosis. For example, animals inhaling heavy concentrations of a mixture of equal parts of pure silica and hematite dust for eight hour.- a day over a period of 14 months have >hown not even the slightest indication of nodule formation in the lung, whereas pure quartz dust, inhaled for only two hours a day. produces definite nodulatmu. it also seems to be true that animals inhaling such a mixture are much less susceptible to tuberculosis than those exposed to pure quartz. In the case of the human iron miner, some lungs show definite silicotic undulation, others only a 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 lung tissues and the approximate amount of rock work which these miners have performed, some relationship between the exposure to silica and -the fibrous nodule formation may be established. Tuberculosis in these iron miners is apparently less prevalent and much less severe than in men exposed to pure silica. W hat 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; Cummins believes that they have the infection but that it is so atypical and benign in its manifestations that it escapes diagnosis. Mention should also be made of mixed dusts like certain slates and granite containing large 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 be true in human beings. Unques tionably such dusts are capable* of producing typical silicotic nodules and they pre dispose to tuberculosis. From a theoretical standpoint they should receive 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 STUART W. GURNEY and DAVID S. BEYER Liberty Mutual Insurance Company, Boston The speaker said in part: A number of bur slates have bad references to dust elimination in their labor laws for a Rood many years, but no state lias as yet thoroughly enforced these laws. The codes of live slates which we invesliRated provide that grinding, buffing and polishing wheels should be exhausted, although two of the states exempt from these provisions wheels on which water is used. Dust in 1industry This seems ill-advised, since a study of wet and dry grinding; in Connecticut by Winslow and (irecnlnirg has shown that the application of water docs not by any means eliminate the dust hazard. It may be remarked that, with everything else equal, a high static suction will give a higher velocity at the point of origin of the dust, fume or gas than a low one; but this alone is not a measure of the effectiveness ofany exhaustsystem Wisconsin has adopted the principle of specifying a limit to the number 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. Thes' variations and conflicting provisions in state codes-merely reflect the gen eral lack of authoritative standards. It is accordingly fortunate that definite steps arc now being taken hv the American Standards Association to develop the proper 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 by the Inter national Association of Industrial Accident Boards 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. lit addition, a Sub-Committee on Fundamental Principles of Design and Operation and Maintenance of Exhaust Systems will he appointed. The two most important considerations in an effective exhaust system are; 1. Velocity of air flow; 2. Arrangement of the inlets (from the standpoint of near ness to the dust source, shape, etc.). Many an 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 scries of tests that were conducted under actual working conditions by Theodore F. Hatch, Department of Industrial Hygiene, Harvard School of Public Ilcnllh. a machine used in dressing stone was employed, and it was noted that with an air How through the hood of 230 cubic feet per minute, there were over one hundred million dust particles in the surrounding air. When the air flow was increased to a little over 250 cubic feet per minute, the dust concentration had dropped to forty million, a marked improvement. As the air flow was further increased, the dreg; in dust concentration was relatively slower, and it took a volume of about 580 cubic feet per minute to bring the dust concentration clown to ten or fifteen 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, bv merely speeding up the blower or adding a larger one, td 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 wc 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 uncommon to see an exhaust inlet a few inches in diameter with which the person making the installation hoped to dr.aw dust from a distance of several feet, but the air flow -even a foot or two away from the entrance to the inlet may be negligible. * Still another important consideration having to-do with the design of the inlet, is the addition of a flange. The effect of this flange is to cut down the air that would flow in from behind the opening, thus drawing it nearly all from the front. Thus the efficiency of the system is substantially increased and the scope of the ex haust extended appreciably, without increasing the power consumption or otherwise adding to the expense of keeping up the system. There arc also other considerations of perhaps lesser importance. For example air cannot be "pulled" from a distance by merely directing an exhaust pipe toward the point in question, but it can be "pushed" or blown, directionally, for a consider- ~S 1 i^cnty-third Annual Safety Congress-- National Safety Council lblc distance. This principle may lie used advantageously in directin'-; the dust `ward tile opening* of the exhaust inlet and thus getting the desired ivsiilts with lower exhaust velocity and power consumption than would he reipiired if suction done were depended upon. This principle has been applied offecthcly in drillin'-; material containing asbestos, where the exhaust inlet is placed at one side of the ; drill and a small air jet at the opposite side of the drill, blowing across the table ! turns the particles that would IIy out from this side and directs them hack into / the exhaust system. It is also being applied to foundry shake-out work. / Other considerations in designing exhaust systems include the elimination nl unnecessary bend' or curves, the p r o v i s i o n o f ele.iu-out doors, and the proper con- structioii of joints. Where there is a general ventilating installation and one or more exhaust systems, care must he taken t" srr thal time do not cnnlliet with each other. After an exhaust system has been installed it should be tested by taking actual dust counts to see that the dust is really being cut down to the desired point, and such counts should lie taken at intervals after the installation has been made, to see that it is still functioning properly. The fact that the dust particles that cause the trouble are so small that they are invisible under ordinary conditions (less than 10 microns or i/25(K)th ot all inch in diameter) often makes it hard to convince the 'practical plant manager that there is any dust present: it also makes it impossible to tell, without the use of spe cial instruments, whether the completed exhaust system is actually removing the dust. It might seem like an insult to one's intelligence to say that after an exhaust system has once been installed it should lie maintained in good operating condition. However, the numerous cases one encounters in the plants where this obvious neces sity is not carried out. indicates that it is really one of the major considerations in Connection with the elimination of dust or fumes. Cases are not unknown where the Idower has in some manner become reversed so that the air is being ejected and diffusing the dust, rather than drawing it in; other instances where the effi ciency of the system has been lowered or its value nullified by clogging up. dis connection or wearing out of the piping, etc., arc all too common. One concern, of which the writers have knowledge, has a "U" tube permanently installed in one of its main exhaust systems so that the foreman or safety man can tell at a glance whether there are any changes that would indicate a break-down in the svstem. All such installations should have regular inspections by some compe tent person as a routine part of their upkeep. It will he sufficient here to discuss respiratory equipment very briefly. The simplest form of this equipment is the filter respirator. Such respirators have a definite value for temporary use such as sweeping up. cleaning out bins, shoveling materials, etc., hut they require careful fitting and constant supervision to see that they are being properly used. It is our opinion, alter watching the sincere elTorts in a number of plants to ! enforce the use of these respirators, that it is rather impracticable to require them ! to he used on full-time operation. One notices the men. under these conditions, i siirrcptitioudy pushing the respirator aside and gasping in free air like a fish out j of water, (.'crtainly, if they are to he used any considerable length of time, fre- t qneiit rest periods should he allowed where the men can get out into the free air for a few minutes refreshment. There are also the large air-fed helm ts. with which most of us are familiar, used for sandblasting, etc., which have been carried to a high stale of perfection for the purposes to which they are adapted. We believe, however, that much more use could he made advantageously of the type of apparatus that lies midway between the filter respirator and the air-fed helmet, namely, the light, air-fed respirator which covers the nose and mouth and leaves the rest of the face exposed. With a light hose attachment, this device offers considerable freedom of movement, and if air outlets were supplied so the hose could be quickly transferred from one outlet to another it would seem to be 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 breathing - that k; imposed by the filter respirator. JJitst in lnattsn y The Medical Supervision of Workers Exposed to Dust By W. J. McCONNELL, M.D. Assistant Medical Director, Metropolitan Life Insurance Co., New York City .The speaker said in part: The hanntulncss of dusts varies widely in accord ance with the physical and chemical natures of each individual substance. Certain dusts are soluble or slightly soluble in the body fluids anil their harmful eftccts are proportional to the toxicit} of the compounds formed. Lead, mercury, and arsenic are examples of poisonous dust. Other dusts- exert their harmful eftccts local!} on the skin and mucous membranes anil through irritation to the respiratory pa- aces. Chronic acid and alkalies are examples. Attention recently has been called to tile probably harmful effect of dusts arising from radio-active ores. A fourth roup of dusts which are insoluble or very difficultly soluble in the- body fluids may initiate harmful pathological lung conditions. These may he subdivided into uon-fihrosis and fibrosis producing dusts. The organic dusts, mainly tlie vegetable fibers, such as cotton, jute, hemp, etc., are non-fibrosis producing dusts. The fibrosis producing dusts are 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 free silica arc admittedly the most important because exposure over a period of years to such dusts distinctly predisposes the individual to tuberculosis. The effectiveness of dust control measures in preventing diseases produced by dusts can he determined only by careful physical examination of flu- worker.-, so exposed under the guidance of competent medical supervision. The benefits which accrue to the employer and employee, alike, as a result of the physical examination of all applicants for employment, as well as periodical examination of those already engaged, would indicate very careful consideration by industry of a program for control of sickness. Such a procedure protects the employer from engaging an applicant already physically or mentally impaired who later may claim disability for a condition either not associated with employment or contracted during a pre vious employment. The applicant's physical and mental condition is established 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 in work for which he is physical!} ill adapted which, if undertaken, might easily bring about serious impairment ot his health. For example, an applicant with an arrested tuberculosis who seu work in a certain dusty occupation, if allowed to engage in such work might readily convert an inactive tuberculosis into an active one: thereby endangering life or at least seriously impairing the applicant's future efficiency and earning capacity. Whereas the same applicant if assigded to a position tint involves no stic-h ex posure, might be 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 communicable diseases such as tuberculosis and various acute respiratory and other infections being introduced into (heir midst by a new applicant. Many of the younger individuals who seek employment have never before re ceived a thorough physical examination and consequently are unaware of the de fects front which they suffer. As a result of physical examinations, man}- defects are located which may he removed or corrected before they have caused irrepat ahlf damage, thereby increasing the efficiency of the worker and often averting definite and finally chronic diseases. Furthermore, incipient tuberculosis, misuspcclcd 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 tare and treatment which otherwise might have been postponed until too late. Of even more importance than the initial physical examination of applicants is the periodic examination and care of old employees by ail industry. Such a pro cedure serves to check the efficiency of preventive measures designed to prevent occupational diseases. It offers the most effective way of controlling the health of 30 Tu'cnly-tliird Annual Sajctv Cont/rcss--National Safety Council large groups of workers by discovering early not only occupational diseases, but many other conditions that go undiscovered until the worker is acutely ill or be comes disabled, if the various contagious conditions go unrecognized others be come infected, thereby causing serious economic loss, as well as endangering the health of a group of individuals. The information obtained from physical examinations affords the medical super visor the opportunity to make certain that employees are engaged in suitable work out of which they are getting maximum results, to correct the effects of 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 employees involved and individual plant conditions. A series of articles under the title of "The Medical Department Manual" by Dr. Hart Is. 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 be 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, he should investigate the extent of the hazards and 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, fb) general infectious diseases, to) respiratory diseases. (<D venereal diseases, and fe) accidents and resulting physical defects. A detailed history of previous occupations engaged in is verv important. A mere statement of the type of industry in which the applicant was engaged has slight value, if any. The exact duties performed in each occupation should be noted and information ascertained as to the probable length of exposure to hazard ous substances. After the history has been taken and a photograph for identifica tion purposes (if part of routine) is made, the applicant should be directed to the examining room where he is instructed to remove his clothing for physical exam ination. This examination should be made as complete as is considered necessary to determine the applicant's physical condition. If the applicant has been or will be exposed to dusts which induce lung dis eases, an X-ray picture of the chest is an important part of the examination. This part of the examination may be referred to an experienced roentgenologist, as the value of this method of diagnosis depends upon the type of pictures taken and the experience of the reader who interprets them. The examining physician also may need additional information obtained by laboratory analv-, of the blood, sputum, and the urine. These aids to diagnosis should be provided or made avail able when desirable. 3. The rating and placement of applicants. Tn cooperation with the personnel department, the applicant should be rated and placed, not only on in's (raining and past experiences, but also on bis physical and mental abilities tn fill vacancies occur ring from lime to time. The record of his physical-and mental examination should be the confidential 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 examinations as determined hv the supervising physician. Where physical examinations are made for the first time, the employees of long standing should be given ample explanation ot the benefits of such examinations and lie given assur ances that their jobs are secure. 5. Provision for the disabled. Kmplnyees who develop disabilities during the course of employment should be re-assigned to occupations which will not interfere with or aggravate the disability, or they should be provided for in other ways. .injO C R N M B X T OSlnSCAif Wr.-ioi.J.-.r.n.eii i ' - *,, -P A f t v sr r <Jt. V 3 '.v. b V ; <s t Tcnty-third Annual Safety Congress--National Safety Council The Dust Hazards in Industry By DR. R. R. SAYERS Medical Officer in Charge, Office of Industrial Hygiene and Sanitation, United States Public Health Service, Washington, D. C. The speaker said in part: Realizing the importance of the dust problem in strv. tlie United States Public Health Service in cooperation with the Jlureau times began its first study of the health of workers in dusty trades in 1914, he mines of Joplin, Missouri; and later, in 1923, the Public Health Service .unrated a series of dust studies. These later studies were all conducted in the e manner in order to permit as detailed a comparison as possible between the rent investigations. friefly, tbe.se methods of study may be divided as follows: (1) examination to rmine the general physical condition of the workers under observation; (2) ial physical examination to determine the prevalence of specific diseases of the iratory system and the lung pathology resultiijg from exposure to the particular hazard; (3) record of the nature and seventy of the disabling illnesses; (4) ysis and detailed study of the occupational environment; (5) occupational tality statistics relating to the specific dust; and (6) autopsies, l'he first six intensive investigations carried put by the Service dealt with the lb of workers exposed to dusts in a cement plant, granite cutting industry, iracite and bituminous coal mining, silverware manufacturing plant, cotton cloth nifacturing. and in municipal street sweeping..1 Brief studies were later conducted certain slate, granite, marble and talc fjuarrics, while more recently a rather nsivc study of the health of anthracite coal miners was completed. These six: dust studies showed that the workers in the granite cutting plants i were exposed to the highest dust concentrations were found to suffer from an :ss of pulmonary tuberculosis alter 15 years or more of exposure and developed osis from 2 to 10 years. In the group exposed to a lesser amount of dust, osis developed only after prolonged exposure, with no excess of tuberculosis, eas found that a close relationship existed between the degree of dust exposure. the extent and severity of the pulmonary damage. Anthracite coal miners ered from dyspnoea and other signs of pneumoconiosis and experienced a high of respiratory sickness ; in addition, an excessive mortality from influcnza- mtonia and possibly tuberculosis was found. Bituminous coal miners experi- :d a generalized fibrosis of the lungs and an excess mortality from influenza pneumonia. Cement workers showed some signs of early pneumoconiosis with excess of diseases of the upper respiratory tract. On the other hand, workers. ic cotton cloth and silverware manufacturing plants and municipal street sweepers e negative for respiratory conditions and other illnesses when compared with general industrial population. , riock DtiUini/. For five years, the United States Bureau of Mines studied lead zinc miners in the Tri-State District, Oklahoma. The ore here is high in free a. Of the 7.722 men examined, a group of 1,647, or 21.3 per cent, was definitely rnosed as having silicosis, not including those diagnosed as having tuberculosis, the men diagnosed as having first-stage silicosis had worked an average of rears, but those men starting in the mines after 40 years of age worked an age of only 8 years. The work of rock drilling in subway and tunnel construction in New York is in some respects similar to that of some of the activities in the bard rock es, at least in so far as the manner in which dust i.s evolved, the type of t and the resultant hazard. Recently the result of a study of rock drillers, ;ters and excavators was reported by the New York Tuberculosis and Health ociation. An examination of 208 rock drillers, blasters and excavators showed 118, or 57 per'cent of the men had silicosis in various stages of progression. exposure of most of these men (75 per cent) had been for 20 years or more. Sandbh~/iinf. No study of the health of sandblasters has been reported in the ted States; however, a study of the dust exposure of sandblasters was recently ipleled by the United States Public Health Service in cooperation with the Quarry Section 3S i National Safety Council. This investigation indicated that, judged by the nature of the dust and degree of the exposure, a real hazard exists in this occupation. This stud}' also brought out the fact that it is possible to conduct sandblasting with safety, provided properly designed and well maintained equipment is used. Dialowaceatis Silica IVorkers. Most of the data on silicosis have been gathered from studies made both in industry and experimentally on dusts containing irce silica in the form of quartz. Such studies have been made in the granite industry, pottery trades, hard rock drilling, etc. There arc other free silica minerals in existence that are not crystalline in nature hut of an amorphous composition. In Santa Harliara County, California, there exists the largest and purest dialnmaceotrs silica deposit in the world. This substance consists of about Sa per cent free silica. Kcccntly an examination was made of 108 workers selected among those employed less than 1 year. 1 to 2 years, 2 to 5 years, and more than 5 years. All of the workers were Mexican laborers and the examinations consisted of x-ray determinations, social and medical histories, and clinical examinations of the chests. Dust determinations were also made hut these were not reported. The outstanding feature revealed by the examination was the splendid physical condition of the men. Eighty-four per cent of the workers were reported in excellent physical condition. It was found that 0(1 men showed signs of early pneumoconiosis: 15 were in the moderately advanced stage and 6 in the advanced stage. This latter finding was among workers with a history of exposure of morethan 5 years. Dust Hazard in the Granite Quarry industry.It is a common belief that granite quarrying 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 dust . 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 granite quarry might cast some light on our problem. Accordingly, a study of a clinicoradiographic nature of 65 quarriers was made and occupational dust exposures were also obtained. The dust determinations show that nearly 58 per cent, of the workers (drillers) were exposed to many times the amount of dust considered safe at the present time. Drillers were the only persons showing pathologic lung changes. Half of these workers with an exposure of 5 to 19 years had silicosis, and 4 of the 5 men with more than 20 years of such trade life showed this condition. This study suggests that quarry drillers may experience as high a death rate from pulmonary tuberculosis as do pneumatic-tool workers in granite cutting sheds. llliect of Inhaled Marble Dust. The pulmonary fibrotic changes due to the inhalation of marble dust appear to be slight in comparison with those caused hy stone dust containing a high percentage of silica in the form of quartz. A recent stud} made by us among marble workers showed that although marble dust, when inhaled in concentrations averaging about 25 million particles per cubic loot of air. produced a mild bilateral, linear fibrosis in a certain number of the 80 men examined, no serious lung changes were noted and there was no disability due to .the dint, even after many years of exposure ('more than 40 years in some cases). The marble dust under consideration consisted of 98 per cent calcitc and 2 per cent dolemitc. with no silica present. Dust Hazard in Abrasive Industry. Artificial abrasives arc widely used in industry and for this reason the effect of the inhalation of dusts produced in the manufacture or preparation of these products is m great importance. In 1925. 1<129 and again in 1951. Dr. Clark of the Norton Company at Worcester. Mass., made investigations of workers exposed to aluminium oxide and silicon carbide dust produced ill the manufacture of grinding wheels, which showed that during a period of 15 years there were proportionately twice .as many cases of pulmonary tuber culosis among those working in the abrasive dust departments as in departments where no abrasive dust occurred. In 1951. Kessler, of New Jersey, reported the occurrence of over 100 cases of alleged silicosis in the abrasive powder industry, in which the dust consisted of 99 per cent tree silica. /fr/'i'.viov hi Silicate Dust. It has been the belief that the inhalation of dusts ciimposed of silicates (combined silica), in comparison with silica (free silica in tin- form of quartz), teas innocuous. Of i cccnt years many investigators have become cognizant of the hazards of silicate dust exposure. Ashcstosis, a fibrosis 52 ixocnt y-third Annual Safety Cantjress-- N otional Sa fety l oiuiat f the lungs caused by the inhalation of asbestos dust, has already been described ] itIt in its clinical and roentuenogranhic manifestations by imestigators in other / .untries, but to date no studies have been reported in the United States. Cement ust. which contains about 22 per cent combined silica, has been studied, and the Tects of the inhalation by workers has been discussed here. In March, 1933, irecssen, of the United States Public Health Service, reported the results of a udy conducted among tremolite talc and slate workers. The slate dust to which lese workers were exposed consisted mainly of silicates, there being less than per cent of quartz in the dust. The talc was a hydrous calcium-magnesium silicate, ing 43 per cent talc and 45 per cent tremolite, with no quartz present. The suits of the study seemed to indicate a relationship between the amount of dust haled and the effect of this dust on the lungs of workers. ,,StulIslii'iit Studies. Recently, T.anza and Vane estimated that there are some >0.0(10 workers engaged in the mining, quarrying and manufacturing industries this country in which an exposure to silica dust to a harmful degree is en ded. Their analysis of mortality experience of twelve life insurance companies r the period 1915-1926 showed that the actual mortality from respiratory tliherilosis among the silica exposed persons was about three times that of a non- lica dust group. If one considers their data for certain occupations in metal ines and granite and sandstone quarries, occupations known to be exposed to gh concentrations of hazardous dusts, then the comparison is more striking, since c actual deaths among these workers was fobnd to be ten times that of the cx- cted deaths. More detailed statistics on occupational mortality as reported hv the egistrar-General of England and Wales f 1921-1923). and summarized by Ijritten. ow the high rate of 1.886 per 100,000 for tin and copper miners, while the rate r "all occupied and retired males" was only 150. Other occupations with silica iposure showed an excess. j From the evidence just presented concerning the injurious effects produced by e inhalation of certain dusts, it is apparent that a knowledge of the properties a given dust which determine its capacity to produce pulmonary pathology is scntial. Numerous investigations of the industrial dust problem indicate that esc properties tire the chemical and mineralogical composition of the dust, its ucentration in the industrial atmosphere, and its particle size. Ill an earlier portion of this discussion evidence was presented which indicated at a close relation existed between morbidity and mortality rates from various spiratory diseases and the exposure to Certain dusts in industry, In the study the (hist hazard in the granite cutting industry, it was definitely proved that ere is a direct relation between the magnitude of the dust exposure and sickness id death resulting from tuberculosis. It is quite evident, as a result of these udies. that the remedy of the dust evil lies in the effective removal or suppression the dust to concentration considered safe. However, no set rules may be estab- bed for the mechanical protection to be instituted in an attempt to control indus- ial dust. Specific conditions encountered in a plant will determine the type of otection to be employed. ' The protection of workers against certain dusts known to be toxic may at lies lie accomplished by the substitution of a non-toxic material for the toxic one. lie example of such a procedure is the possible use of a metallic or other type artificial abrasive for sand in the sandblasting process in those operations in lich it is not essential to use sand, a substance high in quartz content. Again, e mechanical enclosure of the dust-creating process also serves to protect the irker. An excellent illustration of this type of protection is afforded by the idem sandblast barrel used inthe cleaning of small objects. Sometimes it is ssilde to protect the worker by the substitutionof wet for dryprocesses, as wet illing instead of dry. In one instance, in the granite cutting study previously entioned, an operator using a diamond point tool worked the stone wet; the suiting dust amounted to 22 million particles per cubic foot. The same operator is then requested to work the stone dry; as a result, the amount of dust reached e high figure of 45 million particles per cubic foot. In tbe weaving of asbestos 1 .th it has been possible to redttee the amount of dust in the air by wet weaving I i.ne-fourth of the amount present when the process is conducted by dry methods.,| lother example of this procedure in allaying dust is the use of a spray of water Uimny .uditm .k">j in Icyner and jack-hammer drillini^ in hard rock, although the new type of Kelly dust trap is now finding much favor for this kind of work. The Kelly trap consists of a metal chamber designed to enclose the drill steel at the rock surface. No attempt is made to secure a mechanical seal with the rock or between the trap and the drill steel. The dust is removed by an air stream and is carried into an exhaust system connected ! to the trap. Kscapc of dust particles through openings between the uneven rock surfaces and the trap is prevented by the air seal produced by the inflowing air. 'Jests made on thi> trap under actual working conditions show that the dust concentration at the worker's breathing zone may he kept down to less than 10 million particles per cubic foot with a 60 cubic foot per minute rate of air flow through the hood. This trap is a step forward in the program <>f dust remov'd ; however, in underground work', such as in mines and suhwavs. there is >till the need to solve the problem of compact dust disposal equipment. Jn 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 feet of practically dust-free air per minute are supplied to the helmet, the worker receives ideal protection.' How ever, one must always bear in mind that the ultimate criterion of protection should he the dust determination of the air within the helmet during Masting and not the quantity of the air supply itself. In must 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, and at times an unnecessary procedure to remove all tlie 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 information can he made available by the type of studies carried out by the Public Health Service. For example, in the granite study alreadv referred to. it dust at the breathing level of about 10 million particles per`cubic fo ot (35 per cent free silica). Studies of (lust removal devices used in granite cutting plants at the tunc ibis work was conducted showed that a linear velocity of 1.500 feet per minute a< measured by an anemometer at the face of the diisl-removal hood, would keep the dust at the breathing level to an amount less than 10 million particles per cubic loot A word should be said concerning personal respiratory protection against dusts. Jt lias already been shown that in the use of positive pressure respiratory devices in sandblasting, it is important to have a well-designed device supplied with about 6 cubic feet of dust-free air per minute to give full protection to the worker. With reference to respirators of the filter type, there is still much to-be accomplished in the design of an efficient and comfortable mask' for continuous use. Of great value are standard methods for tiletesting of the efficiency ot respiratory pro tection devices. Drinker advocates testing a device against the particular dust which the respirator is to encounter, these tests to he made both in the laboratorv and under actual industrial conditions. He further suggested that some impartial agency should conduct' Mich tests and certify the devices for industrial use. the work being done on a cost basis. The U. S. Jhireau of Mines has prepared Mich a schedule for testing and approving respirators. I wish to stress the importance ot good housekeeping in the effort t<> combat the dust hazard. Good housekeeping should not only imply the removal of accumu lated dust about a workroom but should also embrace efficient maintenance <>' dust removal devices and respiratory protective equipment. Systematic inspecte-i. of all dust suppression equipment should he an axiomatic principle in every dusty industry rather than the casual attention which it now receives in many instances. Report of the Nominating Committee The chairman called for the report oi the Nominating Committee at this point, and new officers lor the section to serve during the ensuing year were nominated and eheted as follows: