Document 1gwqJd4pVwV3yVoy4mvZ9gvOK

NATIONAL SAFETY COUNCIL, Inc. KANSAS CITY, MISSOURI OCTOBER 11 to OCTOBER 15, 1937 Municipal Auditorium Copy'ifHl, 19JT, National Safety Council, Inc. ojrewordi THIi Transactions of the Twenty-sixth National Safety Congress, 1937, are published by the National Safety Council in two volumes. This, the first, contains the general, the special subject, and the Industrial.Section sessions. The second volume contains the sessions of the Child education, Home Safety, Street and Highway Traffic, Commercial Ve hicle and Transit Sections. * All'industrial members of the Council automatically receive ( Volume I. Volume II is sent to members believed to be inter ... ' estei.1 chiefly in the sessions it covers. Other Council mem " hers, however, may obtain it upon request. . .. Many members have found it worth while to distribute *, copies of the Transactions to supervisors, foremen, and others in an administrative or supervisory position who may make practical use of them for reference purposes. The fol lowing quantity prices are quoted on extra copies: 1 to 10 copies of the large volume (Volume 1), $2 each; 11 copies ' or more. $1.75 each; copies of the smaller volume (Volume 11:1, 75 cents each. THK Transactions arc published as a condensed record of the proceedings at the National Congress. The papers of each session or division of the Congress have been edited carefully to eliminate extraneous matter and to abbreviate the less essential portions because of space limitations. Thus the material herein presented is not a verbatim report of all the speeches presented at the Congress, but rather an abridged version made as compact as possible, yet without injury to the technical aspects of any address. The original manuscripts arc on fide in the Council's llureau of Informa tion, where they are available for additional reference. Where illustrations were sent by the speakers to the Council, these also arc on file. The National Safety Council at its Congresses seeks to ' eliminate from discussion matters which are not pertinent to the aim of the Congress or which are contrary to Council policies. It cannot accept responsibility for the views ex pressed either in the papers presented or in the discussion', based upon the papers. NATIONAL SAFETY COUNCIL, Inc. 20 North Wacher Drive Chicago , Council Officers and Directors...................................................... 4 Council Purposes and Policies...................................................... 9 Annual Meeting of Members.........................:............................ 11 A'nnual Banquet ............................................................................... 31 Subject Sessions--- After Work Accidents........................................................... 33 Agricultural Safety................................................................ 41 Community Safety Organization......................................... 51 Fire Prevention ...................................................................... 59 Healtlj.Servicc'in Industry............................ 71 Industrial Dusts ..................................................................... 85 Indusj^,ial Fumes, Gases and Vapors.................................. 99 Industrial Safety Lectures................................................. ..109 Mainlining Interest in Safety..............................................141 Pressure Vessels ..................................................................... 157 Safety Fundamentals ............................................................... Safety Inspectors ................................................................... 183 Safety Training ................................................................ J93 Safe Use of Acids.............................................. 7...................201 Aeronautical Section...................................................................... 211 A.S.S.E.--Engineering Section.....................................................221 Automotive and Machine Shop--Power Press Sections..........225 Cement and Quarry Sections..........................................................249 Chemical Section ................................. 271 Construction Section....... .............................................................. 285 Food Section............................ ;..................................................... 307 Industrial Nursing ..........................................................................323 Marine Section . ........................................................................... 341 Meat Packing, Tanning and Leather Industries Section....... 371 Metals Section.................................................................................381 Mining Section..........................................................................-....401 Paper and Pulp Section...................................................................429 Petroleum Section ..........................................................................489 Power Press Section........................................................................ 535 Public Utilities Section.......................... 537 Quarry Section.........................................|.....................................557 Refrigeration Section ...................................................................... Rubber Section ................................................................................. Safety Equipment Section................................................................... 581-- Steam Railroad Meeting............................ '...................................587 Textile Section ............................................................................... 501 Wood Products Section................................................................ .. Index ......................................................... I................................... 821 i> \ r Ikes. HONORARY MEMBERS Assort \tios ok Ikon" .\ni> Su.i:i. Engineers \ Rom kt W. Cvmi'HI 11 Lew R. I'ai.mi.k . OFFICERS (1937-1938) I). .). I'i.nst.ii, President . C. W. Di.mpesv, Vice-President tor Pittance and Treasurer Hakuv ("lull.nt.KT. Vice-President for Membership KiiwK II. I Iaukiso.v. Vice-President for Industrial Safety 1 Ion. Harold G. Hoitmax. Vice-President for Public Safety ' U'.M.mi S. Paine. Vice-President for Engineering A. V. Rhiiweiilh, Vice-President for I.ocal Safety Councils A. \V. Win 1 xt.v. Vice-Pre-ident for Education W. H. Cameron', Secretary and Managing Director . EXECUTIVE COMMITTEE (1937-1938) H. W. As'ULkMiN, General Motors Corporation J. I. Banasii, Past President C. \V. lir.RGouisT, Past President Ilt.N'KV W. Boggess, Pclroleuin Section C. ft. Ilnt'ixr, ASSE-Engincering Section H. \V. Boulton, Automotiec and Machine Shop Section Harold S. IiunESHtm, The American City Magazine W. H. Cameron, National Safety Council, Inc. Uom kt W. Camvhlll. Pa-i President KoiiikT I. C.\li.in', Aetna Casually *v- Surely Company U. A. ClIU'HN, Metals Section Lewis A. Dr.Ui.ot>. Past President C. W. Dempksy, The Liquid Carbunic Corporation M Mill's A. Dow, I'.i't President 1). 11. piNSLl.i, Consultin',' Engineer Jonx It. Gtnsos', Western Ekvlric Company Harry Clui.lour, The Pullman Company Frank If. Harrison, International Harvester Company P. L. G. H \s>Kski, Lehigh Valley Safety Council IIi>n, Hamiii) G. IIoit'.ma.v, Governor, Stale of New Jersey S. II. IIorkeli, l:ood Section Waiter G. King, Past President . 4 OFFICERS AND DIRECTORS, Continued Wm. C. Knuei.k, Milwaukee Safety Commission . Jims' E. Long, Past President Tuns. H. MacDonald, U. S. Department of Agriculture ' Wai.ti:k B. Martin, Peoria Association of Commerce Safety Conn I. W. Mii.i.ako, Industrial Gloves Company Harold L. Miner, E. I. du Pont de Nemours' iV Co. Prol. Roger L. Morrison, Street & 1 lights ay Traliie Section E. J. O'Buien, Jr, Louisville Safety Council ` WAt.|Ljt S. Paine, Aetna Life & Affiliated Cos. I.kw R: Palmer, Past President C. KtifcljElTliiONE, Past President Ai.ulrt S. Rlgui.a. Industrial Relations Counselors, le\ I.t. C/yl. Henry A. Rfnincer, Past President A. V. Knit weoer. Do hull, Missahc & Iron Range Railway Co. Gldhgi: E. Santoro, General Electric Co. Charles B. Scott, Past President Gen, John H. Sheriiurnf, Massachusetts Safety Council ,, Judge Lee E. Skeei, Cleveland Safety Council C. W. Smith, Standard Oil Company (Ind.) Walter Dent Smith, Delaware Safety Council R. T. Solenstex, Elliott Service Company "* C. P. Toi.man, Past President _ Georoe G. Traver, Greater Chicago Safety Council, Inc. Dr. C. H. Watson, Past President A. W. Whitney, National Conservation Bureau T. A. Wilson, Textile Section W. E. Worth, International Harvester Co. Arthur H. Young, Past President DIRECTORS (1937-1938) George J. Adams, Paper and Pulp Section II. W. Aniilkson, General Motors Corp. A. L. Armstrong, Eastman Kodak Company 11. II. Bailey, Chattanooga Safely Council I. I. Banasii, Consulting Engineer Carl Barker, St. Louis Safety Council Ci. J. Bvrrlit, Mining Section Ernest W. Beck, United Slates Rubber Products, Inc. C. W. llERGrjiasT, Western Electric Co. ,-,E. I'. Blank, Jones & Laugblin Steel Corp. I [i nks' W. Boor,ess, Petroleum Section H(, E. Bolt, South Bend Civic Safely Council S Il fFICERS AND DIRECTORS, Continued C. 15. Roui.lt. ASSE-Enginccring Section , H. W. Boulton, Automotive S: Machine Shop Section 1'. S. Meows, Standard Accident Insurance Co. \V. A. liuows, Safety Department, Nashville Chainhcr of Commerce W. T. I'i.cKi.kiui'.i:, F.inploxces' Publication Section S. W. Iti'KCiiiM., Sat'ctx Department, Automobile Club of Rhode Island ll.uiuf.ii S. Ilia rKNiinxi, The American City Magazine 15. J. Cxi t-M.iixs, Contra Costa County Safety Council \V. H. Cameron, National Safety Council, Inc. U.xv Carney, Kenosha Safety Council Kom iir I. C x u is. Aetna Casually S: Surely Co. I{. A. Cii.xms, Metals Section Kt.NSK.iii 1>. Coi.man, Seattle Traffic & Safety Council J. E. Cui.i.inev, licthlehcm Steel Co. . Lewis A. DkUi.ois, Consulting Engineer ,' J.xv E. Decker, Mason City Safety Council C. W. DemflsY, The I.iipiid Carbonic Corp. James U. Doui.i. xs, The Philadelphia Gas Works Co. Dr. Louis I. Duhi.in, Metropolitan Life Insurance Co. O. M. Edwards, Jii...Safety Div., Syracuse Chainhcr of Commerce W. \ Ki-Siux, Public Utilities Section I). 1). Flnnli.i.. Consulting Engineer D. I.. Fennell, Kansas City Safety Council Don.xi.ii A. 1"inki;i:im:r, Toledo Safety Council Dk. II.xkt E. Fisher, Chicago Rapid Transit Co. . Cnisri.ic C. Fisk, Merkeley Trailie Safety Commission IIiixv.xku 15. 1'oniix, Murroughs Wellcome & Co. (U.S.A.) Inc. Alexander 1;ostu:, Ju., Quarry Section . John 15. C.insnx, Western Electric Co. Howard F. Gii.iiert, Elizabeth Safety Council Onto M. Grams. The General Crushed Stone Co. W. A. Griffin*, American Telephone S: Telegraph Co. . Harry Guii.iikrt, The Pullman Co. IsAt aii II alu. The Atchison, Topeka & Santa Fc Ry. Co. C. H. H xritr. Refrigeration Section D. T. IIxhrinoion, U. S. Mureau of Mines Frank H. Harrison. Inlerualioual Harvester ('. P. L. G. IIasskxri, Lehigh \'allcy Safety Council R. C. Havln. Commercial Vehicle Section G. T. Ilri.l.xiLTH, Chicago, North Shore & Milwaukee Rli. Co. CltAS. E. llll.l, Nexx York Central Lines llo.N. 11 XRol.n G. Hoffman, Governor, Stale of Ncxv Jersey K. C. Hoi hex, Jr.. Maiinc Section 6 OFFICERS AND DIRECTORS, Continued Evkkutt Horii, Madison County Safety Council S. 15. Hokrmi., hood Section H. C. Hoxvsaxi, Puxxcr Press Section Fred II. Hunt, Cement Section Major Norman A. Ixiiiii:, Columbus Safety Council R. D. Jlxvi.tt, Springfield Safety Council Thomas P. Kkakns, Industrial Commission of Ohio Thus. L. Kei.i ey, Paterson Safely Council J. M. Kekriu.xn, Rubber Section Wm.'Cc Knoli.k, Milwaukee Safely Commission W.xi^j. Knudsen, Detroit Industrial Safety Council C. L. CaFountaine, Great Northern Railway Co. Mill,xrd C. Leei.eh, Child Education Section BarnA* Levy, Jr., Rochester Safety Council A. Aucustus Low, Lirooklyu Safety Council . TltOS. H. MacDonald, U. S. Department of Agriculture Walter B. Martin, Peoria'Association of Commerce Safety Council F. W. Matson, Minnesota Safety Council R. A. McArthur, Transit Section . Miller McCi.intock, Harvard University - I. W. Millard, Industrial Gloves Co. J axils K. Mii.i.lk, Grand Rapids Safety Council Harold L. Miner, E. I. du Pont do Nemours & Co. R. 15. Mori.ev, Industrial Accident Prevention Assns. Pkok. Roger L. Morrison, Slrcet & Higlmay Tralbc Sectiou Ernesr Mhkitiy, Albany Safely Council E. J. O'Brien, Jr., Luiii.-ville Safety Council Georoe C. A. Opp, The Detroit Edison Co. Walter S. Paine, Aetna Life & Affiliated Cos. Lcxv R. Palmer, The Equitable Life Assurance Society of the U. S. David A. Patton, Ncxvark Safety Council Mrs. G. if. Pei.to.n, Exauston Safely Council Charles W. Pendock, Safety Div. Milxxaukec Association of Com merce C. E. Plttioonk, American Mutual Liability Insurance Co. Gi n. Gi.okgi: 15. Pii.i.siil kv. United States Engineer Office Arthur Pgttektox, Hudson County Safety Council Ai.reut S. Recui.x, Industrial Relations Counselors, Inc. , Lt. Col. Henry A. Kf.mnt.eh, Lehigh Portland Cement Co. Bestor Rouinson, Eastbav Safety Council ,-,A. V. Rouwr.bEK, Duluth, Missahc & Iron Range Ry. Co. Walter Roseniiaum, Western Pennsylvania Safety Council Ci E. Sanford, General Electric Co. i \ 7 OFFICERS AND DIRECTORS, Continued Henry G. ScilAKFNr.it, Eric Sufclv Council Karl G. Schoefit.ur. Rahway Safety Council Hakry A. Schultz, United States Steel Corp. H. E. Seely, Wood Products Section ' Earl S. Shartzf.r, Utica Safety Council Gen. John H. Sherburne. Massachusetts Safety Council Dr. L. A. Shoudy, Bethlehem Steel Co. ' Ernest L, Simonds, N:ew Haven Safety Council A. E. Sinclair, Meat Packing, Tanning & Leather Industries Section .. Judge Lee E. Skeei, Clcvelantl Safety Council C. VV. Smith, Standard Oil Company (Ittd.) Edwin C. Smith, Blackstonc Valley Safety Council Walter Dent Smith, Delaware Safety Council W. A. Snow, Construction Section R. T. Sot.ENSTEN. Elliott Service Co. E. C. Spring, Lansdalc. I'a. George R. Stephens, Safety Bureau, Buffalo Chamber of Commerce Joiiif'STH.wixi, Greater New York Safety Council Arthur M. Tode, Consulting Marine Engineer George G. Tkaver, Greater Chicago Safety Council. Inc. # Major R. D. Trimble, Richmond Safety Council Frank E. Vitz, Superior Safety Council Dr. C. H. Watson, American Telephone & Telegraph Co. Harry M. Webuek, Wilmette, 111. Dk. David E. Wegi.kin, Baltimore Safety Council S. E. Whiting, Liberty Mutual Insurance Co. . A. W. Whitney, National Conservation Bureau Howard R. Whitney, Worcester Safety Council T. A. Wilson, Textile Section \V. H. WtNANS, Union Carbide & Carbon Corp. . I-\ B. Winslow, Safety Die., Birmingham Chamber of Commerce W. E. Worth, International Harvester Co. K. J. Zauft, Safety Bureau, Duluth Chamber of Commerce t>. L. Zwick, St. Joseph Safety Council purpo The throw. - prever plies tdirectl lation. Rcr condit. diseas> accidc tive it. The profit. tion. It ha sentin. of the 400 fw hcrslu indiv;. hers oi tions. cerne. the mi the V and r. The the fir under Tron i wauki Cone. organ inemlx bersl.i; The gram unnedevu. make Tin expat. Industrial Dusts j WEDNESDAY MORNING SESSION October 13, 1937 The meet ini' was railed to order by Chair- York City, and Vice-President tor Engineerman A. S. Eegula, Executive Secretary, In- ing, National Safety Council, who introdustrial delations Counselors, Inc., New dneed the speakers. What Industrial Dusts Are Harmful? Why? By SENIOR SURGEON R. R. SAYERS Chief, Division of Industrial Hygiene, U. S. Public Health Service . While dusts exist everywhere in the at is difficult to establish a comprehensive mosphere, it has been recognized for cen definition for toxic dusts. Sollmann,' after turies that workers in certain dusty analysis of various definitions for poison, occupations are less healthy than those not felt that it is very difficult to give a definition so, exposed. ^The number of persons ex which will not be ambiguous in some cases, poseddusty occupations comprises one but believed that the following covers most of the largest industrial groups. The occu of the points which must be considered in pational diseases of workers in dusty at classing a substance as such: r. mospheres have been found to be due to entrance of dust into the system by inhala tion. by ingestion, by direct absorption through the skin, by irritation of the skin, or by a combination of the foregoing. The suspensions of particulate matter in air have been broadly termed dusts, fumes, and smokes. Such a classification is neces sarily arbitrary, since'the line of demarca tion between them is not very sharp, and the chief differentiation is based on the size of the particles. Investigations by the Pub lic Health Service in dusty industries' re "A poison is any substance which, act ing directly through its inherent chemic properties, and by its ordinary action, is capable of destroying life, or of seriously endangering health, when it is applied to the body, externally, or in moderate (loses (to 50 Gin.) internally." Some dusts arc known to be poisonous, while others, in the concentrations usuallv encountered, are comparatively harmless. 1 lowevcr, it may be stated that breathing dust in high concentration is not desirable. vealed that about 70 per cent of the dust According to Fairhall, the damage arising particles examined were between 1 and 3 from the inhalation of toxic dust may be microns in size, only about 20 per cent were either local or remote, and depends upon less than 1 micron, and the median size was whether the material is a protoplasmic poi 1.3 microns. Industrial dusts arc mainly less son, whether it is caustic in reaction, or than 10 microns in size. However, fibrous whether it is absorbed into the blood stream dusts in the air, such as asbestos, have been and carried to other centers which arc in found to contain particles as large as 200 turn affected.' 400 mireous in the greatest diameter. It is now well established that exposure While, generally speaking, according to to certain kinds of dusts, such as those con Collis, tlusts arc more injurious as their taining considerable quantities of free silica, chemical composition differs from that of has increased the morbidity and mortality the human body, or from the elements of rate from respiratory diseases; while me which the body is normally composed,1 it tallic dusts, such as lead and its compounds. 35 have been associated with general systemic poisoning.* Dusts may be sw allow cat with .'alien, water, or food, and direct poisoning lias been traced to absorption I'V Ibis niclliod; oilier dusts may act as irritants and produce affections of the skin, irritate mu cous membranes of nose, eves and throat,. often causing inflammatory diseases of these organs.* Some inorganic dusts arc able to pene trate the deep lung tissues and arc sufficiently insoluble to be retained there. Some of these may be active in the human tissues, causing definite and permanent in jury. while others arc inert and may he retained for years, apparently without seri ous damage; some are gradually absorbed without causing pathological changes.' All inhaled particles are soluble, at least to a small extent. If harmless, cell activity is stimulated so that phagocytes remove the dust. If the solute is toxic, the viability of the phagocyte is affected and an ineffective accumulation results. At the same time, further solute may diffuse into neighboring tissues, setting up an irritation and subse quent fibrosis. The nature as well as the solubility of the solute is an important fac tor, but of two substances of approximately equal toxicity, tbc more soluble form causes the greater damage. However, sub stances of such low solubility as silica may ultimately produce extensive injury.' Kettle has stated that harmful dusts, if inhaled into the lungs, may activate a latent tuberculous infection; they may exaggerate on active tuberculous lesion or a coincident infection. If sufficient quantities of a harm less dust arc inhaled, some of it remains in the lungs and causes a mild degree of fibro sis merely through mechanical irritation, but such fibrosis is never sufficient to inter fere with the function of the lung." Some writers state that while the influ ence of iioiipoisouous dusts on health is a debatable subject, abnormally high death rales from bronchitis and pneumonia arc sometimes attributed to chronic exposure to nontoxic dusts. Large amounts of dust arc occasionally found in supposedly nor ntal lungs, at autopsy.* According to Drinker, there are four dif ferent types of reaction produced in man by the inhalation of dust. The first ami most important arc the pneumoconioses, such as silicosis and asbeslosis, which cau;c sprrific lung pathology and often are followed by pulmonary tuberculosis. .The second type of reaction is caused by toxic dusts like lead, cadmium, and radium. A third type of mal ady follows the inhalatiotV. of finely divided metallic fume particles sueli as zinc oxide, and is known as metal finite fever. The fourth reaction, allergic id character, is caused by breathing organic dusts such as pollen and certain types of pulverized wood and flour. In all four cases the sole cause of the disability may be dii't inhalation, but the reactions from toxic dusts result from swallowing as well as from inhalation." I-'or various reasons it is difficult to set up an absolute classification for dusts. Opinion is rapidly changing regarding socalled inert or harmless dusts and further investigation may prove some of them to he injurious. Some dusts may have both a toxic and an irritant action; while on the other hand, the poisoning resulting from ex posure to a dust may he the combined effect of more than one mode of entrance into the body. However, the following classification of dusts, according to physical character istics and physiological effect, is used for convenience. I. Organic Dusts . Organic dusts are those which contain carbon, and were originally supposed to come from organized substances derived from animal or plant life. Living dusts route under this classification, and arc thought to be of tbc same order of size as industrial dusts, with which they arc fre quently associated. Haclcria arc usually be tween 0.5 and 3 microns, except jn a few rases, such as the anthrax bacillus, which ranges from 1 to P.25 micron in breadth and 4.5 to 10 microns in length and 10 or 12 .microns in diamclrn.jjJ low ever, it is possi ble that tbc larger and heavier varieties, like tbc larger aml.-jigavicr dust pat tides, settle slue to gravity/ and do not remain suspended in the air. Many thousands of organic substance-, rarhon-coiitaiuing, are marie synthetically by chemical processes, such as dyestuff-, explosives, etc. I. XnS Ul IXG ORG.IXIC IH'STS. As lire name implies, these are comprised of iionviahlc particles, which may oi may not be inherently toxic or irritant, but wbirli nevertheless produce untoward effects in lire human organism. ``Allergic" dn-ts, or those to which only certain person arc oi may become hypersensitive, with resulting dust, or powder form of the prcparatioi asthma, rhinitis, or other disturbances, are erting a direct irritating clTo I on the s included in this classification. Dermatitis due to other vegetable < a. Toxic nitd/or Irritant. Toxic or irritant such as vanilla, powdered arnica, ; dusts arc all organic dusts which produce thrum, etc., have been reported." untoward symptoms, either systemic or Dental lesions, of occupational or local. Those producing local symptoms are have been reported among workers in si usually described as irritant; those produc The gingivitis caused by sugar dust is ing general or systemic symptoms are sified as purely mechanical, with I. termed toxic. A dust may be both toxic and developing caries. Digestive dison irritant. respiratory conditions, and cutaneous In reported eases of injury or death fol ditions (especially of the face) were lowing inhalation of dust from organic com found." pound*. among the chief offenders are Dock workers, transporters of g paranitranilinc, the dinitrobcnzcncs, chloro- workers in grain and flour mills, etc. diuitrobenzcncs, trinitrophcnol, and nilro- exposed to dusts during their work. I) unphtliaU'MC. Eye damage due to inflamma from cereals may contain many impuri tion of the cornea has occurred among which may cause an irritating action on workers exposed to methyl violet dust. The respiratory passages, as well as inflam dust from paraplienylcnc diamine derivatives lion of the skin. Digestive disturbar is particularly irritating and dangerous, dental defects, diminution in hearing, causing not only a severe form of derma conjunctivitis have been observed an titis where the dust comes in contact with millers, ami have been attributed to the rl the skin, but also producing acute inflamma to which such workers arc exposed." tion of the mucous membrane of ' the respiratory passages.* Toxic dusts may be generated during the handling of powdered dye* ami in preliminary dyeing operations, particularly the hydro-extractor process, where particles arc disseminated in all di rections." Coal tar and indigo dyes are substances most frequently used. b. Allergic. Many apparently innoct substances may produce reactions in i sons of peculiar personal susceptibility. ' term "allergy" is used to describe this r dition of hypcrscnsitivcnc*' or susrcp!i,'i' and allergic phenomena most freque manifest themselves in skin reactions, lb ever, they may cause nrutc reactions r Cases of amblyopia have been reported where in the body. When the rcspir.it from exposure to inhalation of tobacco tract is involved we have such wrll km dust." It lias been found that inhaled to diseases as hay fever or asthma. Tb bacco dust exerts a nicotine action on the diseases may develop as a rcsi.lt of by; organism fifteen times greater than that sensitiveness to such substance, a* poll produced by tbc same quantity of smoked irom plants, horsehair, rabbit'., fur, fi tobacco with an equal nicotine content." feathers, ctr. j Severe dermatitis is experienced by many workers handling powder containing T.N.T., which is used in making high explosive*. Picric acid, which is also used for this pur pose, requires drying, and in this latter state has been found to produce a dermatitis. Picric acid is also the oldest synthetic or ganic dyestuff." Dermatitis occurs among handlers of silk with varying frequency. Sails determined that a ra*h occurring among workers in a silk factory was due to b'or instance, furriers, workers hi cloth industries who arc expo-oil to wool ib etc., may stilTcr from bay fever or a-llur It i< umieeessary for the ollri'ding du-t rcaeli tbc depths of tire lungs--pnlb for example arc reported to produce lb effect after being cajigbt in tin upper r piratorv passages. Should such : a offend substance be finely ground it < viild re: the alveoli and as a result probably physiologic reactions would be accelerate dust . from silk cocoons imported from In a survey of a plant where rr-in Africa." mixed, ground, and molded, it was ton Persons engaged in the manufacture of that 811 per cent of the occupational dent quinine and quinine preparations suffer from titis there was due to hef>er.rrisilii ity skin phenomena, which occur for the most hexamethylenetetramine a.id formablvliy part on exposed parts of the body, and contained in the dust to which the worki may he caused by ingestion or hv quinine were exposed." During the first proec'- cut ton spinning. collon-strippcrs are ex- liiehum dermatodcs), which is scattered d lo dust arising from cotton husks and when the hark is stripped off. This powder ris. which produces a typical form of is irritating to the skin and mncuu< mem iunn.' ! branes. M)celia and spores of (.moulds arc irdinary wood du-t has been of interest commonly fuiind lo cause rashes: for in r to its purely mechanical action, but stance, the black powder eoiniiig from II greater care is required in handling macerated sugarcane stalks. Among basket- Inin hinds, especially woods coming from makers. the mycelium and spores, in the road, because of the essential oils impreg- form of a white mould (hjphomycete) from ting limn, which when freed in the dust the rlintlan canes used, get shaken out when v affect the health of the workers con the canes arc split, hammered, and cut, ned. Some of the woods capable of causing painful fissures lo develop on the nine -kin lesions arc Brazil wood, satin- skin where they alight." .'<1. leakwood. cuniaru or tonka wood, A form of asthma or spasmodic cough, ck ebony wood. West Indian mahogany, suffered by cotton weavers 'and known as .ane-c lagavasan, coccoloba, cliestmitwood, aspergillosis, has been considered due to in vcwood. California sequoia, etc. All per halation of spores of a mildew which some ns who handle these woods are not in- times occurs oil the threads." In a study red, only those particularly susceptible to of silicosis among miners, made by the e substances they contain becoming Public Health Service, a number of eases rectcd." - of typical miliary calcification were en 2. LIUSC. ORG.-IS1C DUSTS. These ntain particles capable of exhibiting the lenomena of life' (especially the property ' reproduction or multiplication), such as icteria and fungi. They are usually found low concentrations and are associated .th nonliving dusts in the air. countered. Unstained smears of those cases examined were positive for fungus, two types of Aspergillus fungi being identified. All of the subjects but one were farmers, teamsters, fccdini 11 workers, or residents of small agricultural towns where grain is marketed. Farmers are exposcil to fungi in threshing wheat, baling hay,' or handling a. Bacteria. One of the most important various small grains." nong these is the anthrax bacillus, which contained in the dust from skins, furs, ool, and animal hair, horns, hoofs, bones. This disease may occur in two forms: -lancauf (in which the organism affects e skin), and pulmonary (when it is inhaled, s in the form of anthrax known as wool- Some other fungus diseases such as actino mycosis and blastomycosis are associated with occupational exposure to dust. The former occurs among workers handling straw, hay, grass, vegetable debris contami nated with mould, etc. Actinomycosis is likely to affect people engaged in commercial rters' disease)." handling, storing, and cleansing of grain Cases ot tetanus, reported in connection (grain distilleries, Hour mills, grain crush ith jute manufacture, were traced to the ing, breweries,'and malting houses, etc.)." iw- material, the bacillus having been found i the factory dust.'1 Diphtheria, tubereu- II. Inorganic Dusts sis. smallpox, typhoid, or other bacillus-oduced diseases, may result from exposure infccteil dusts. Inorganic compounds arc ol mineral origin, not requiring a living organism lo produce them." A number of dusts not Bacterial sensitization can he the cause of usually classed as toxic may, under some ty of the allergic diseases, namely, asthma, conditions, produce untoward effects on the vrcimial. hay fever, urticaria, angioneurotic human organism. Classified under inorganic lcina, eczema, or migraine headaches." arc toxic and/or irritant, fibrnsis-pioduc- h. Fungi. Dusts containing the mycclia ing, and nonlilirosis-prodiicing dusts. id spores of parasitic fungi give rise to a. Toxic and/or Irritant. Toxic dusts arc iinoyancc and discomfort. ".Maltster's" itch those which are inherently toxic when in om the dust alone has been reported. In haled. ingested, or otlici wie absorbed. rovence, reeds used for ceilings arc stacked Among those which produce systemic poi hilc still wet and undergo fermentation; soning, some of which are also irritant, arc :ey become covered with a while powder the dust'- from heavy metals and their salts, a dry fungus of the Mucor family : Sporn- such as lead, inercui<. arsenii, cadmium. zinc, etc. Irritant dusts arc injurious by reason of their strong irritative or corro sive properties. As a rule, inhaled irritant substances im mediately cause a reaction in the upper respiratory tract of such severity that they are prevented from reaching the lungs, al though they may cause lung damage by extension of iunamiiiatioil if the mucous membrane is corroded.1 Lime, calcium oxide, and the di-cliromalrs are examples of irri tant dusts. An inorganic dust may possess both toxic and irritant properties, and the poisoning produced may be the combined effect of more than one mode of entrance into the body. Of the directly poisonous dusts, the most widely prevalent are those of certain lead compounds, particularly the oxide, carbon ate and the chromate. The dust is readily absorbed hv the mucous membrane; some dust passes into the stomach and is dissolved by the gastric juice.* According to Fairhall, perforated nasal septum is a common occurrence among workers with bi-chromate dusts.* In a study made by the U. S. Public Health Service it was foi^nd that continuous daily exposure to concentrations of chromic acid mist greater than 1 milligram in 10 cubic meters is likely to cause definite injury to the nasal tissues." It is believed that a similar concentration of the dust would be equally toxic. . In the case of poisoning from some heavy metals, exposure may be to both dust and vapor. For instance, investigations have shown the safe limit of total exposure to lead oxide dust and fumes to be less than 1.5 mg. per 10 cubic meters of air, except for prolonged exposure.*" In exposure to mercury dust and vapor, it was shown that the incidence of chronic mcrcurialism in creases rapidly with increasing mercury concentration, after such concentration ex ceeds 2.0 mg. per 10 cubic meters." Alkalis and metallic oxides arc common causes ot dermatoses. Lye. potash and lime arc known to cause irritation to plas terers. rement-makers. bricklayers, masons, stonecutters, modellers, and metal platers.'* Ulceration and perforation of the nasal sep tum occur among workers exposed to the dust of soda ash; systemic poisoning also occurs from inhalation of calcium cyanimidc dust." Cases of dermatitis, scleroderma and can I cer are reported' to have, been t.' cd by exposure lo dust of arsenic eon pounds. Certain aluminum salts are skin ; rilanls and aluminum dusts may coutrilmjn to the infection of skin and mucous men, .r,mc. through mechanical action." h. Fibrosis-Producing Dusts. The ino-t important of these are the inorganic, slightly soluble du-ts which cause fibrous changes in the lung tissues, some of which are seri ous, and some of which cause little or no disability.1 So far as is known, no inorganic substances other than silicon derivatives cau-c more than a very moderate degree of fibrosis of the lung. Morcovci, there 'ccms lo be no evidence that any oh.er constituent of ordinary dusts can influence so unfavora bly a pulmonary infection.' Although other dusts, when inhaled in sufficient concentrations over a long period of time, have been shown capable of pro ducing a pulmonary fibrosis, nevertheless, the pneumoconiosis characterized by nodu lar fibrosis has to date been shown clini cally and experimentally to be associated only with the inhalation of dusts containing free silica. Since this dust, to exert its harmful action, must enter the finer divisions of the lung, the particle size of the atmospheric dust may hear a definite relationship to the in jurious effect produced. The silica must be present in tlc air in particles small enough to enter the finer air spaces and of stub dimensions that the phagocytic cells may engulf them. The greater majority of par ticles found upon microscopic cxaiiiinnliov of the lung fall within the limits of Irom 1 to 3 microns." Examples of siliceous dustare granite, quartz, sand, pumice, slate, etc. In a recent study among anthracite miners, the correlations between exposure to dust (which contained silica) and the evidencof constitutional changes left little doulc as to the etiological significance of the dust in the air breathed. Like correlations were found between the silica exposure and tinextent of pulmonary changes." \\ hen tin inhaled dust consists of silica combined with base', silicates, some degree of change in the pulmonary tissue may result. In this respect asbestos dust seems to he unique among silicates in the prevalence and se verity ot the disease it causes." The chief distinction between silit .-is an 1 conditions due lo simple reactions cau-i by other dusts is the active prolifciati' oaclion in the tissues which result! in .ingicfsivc iiodiitation. Silicosis, when onct .`tnldished, strongly predisposes tin: lungs o infection, especially witJi tlic tubercle 'ucillus. Chronic interstitial pneumonia, hronic bronchitis, and emphysema arc fre- pient complications of advances! degrees of -ilicosis. The relation of the acute respiratory iu- 'cction* to the reaction due to dusts oilier han free silica has never been established, hough a heightened incidence has often vvn shown statistically in workers in dusty miles. It is fairly certain that a dust dam- <cd Inns;, whatever the cause, fares much ..irsc if an acute infection does supervene ni'iiii it.' , ' In a study conducted by the U. S. l'nlilic Health Service among marble finishers in Vermont, it was loimd dial marble dust when inhaled in (he concentrations found in die examined plants produced a mild, biateral, linear fibrosis in some cases, but no -crious lung changes were noted and there was no disability due to the dust, even alter years of exposure." c. .Vonfibrosis-Producing Dusts. These ire inert, that is. they do not cause fibrous tissue to he produced, hut may become encapsulated or lie free in the tissues; or they arc absorbed without production of fibrous tissue. Included among them are alundum, coal, corundum, emery, limestone, magnesite, marble, plaster of paris (gvpmtt), nod polisher's rouge. Dust may be entrapped at its source by .Miction devices and thus removed and col lected. Familiar examples are exhaust hoods in grinding operations, anil the devices used in rock drilling. '* Generally speaking, the exhaust ventila tion method, where applicable, is to be pre ferred in controlling a dust hazard. Water may be used to entrap dust and prevent its dispersal, and under certain circumstances it may be of advantage to combine the ti-e of water and the use of suction. .Sometimes a dusty process can he completely enclosed in a sealed room or roinparlment. It mu-t he remembered, however, that any mechani cal device of this kind offers adequate pro tection only if it is properly designed, installed, ami maintained. A great deal of attention has been given the subject of individual protection from dust, ami there are many types of respira tory protective devices now available. These are generally of two types: those which provide fresh air from an 'unconlaininatcd source and those which rely upon a filtering medium for removing dust from the air breathed. Where the use of such a device is indicated, only one of the .types approved by the U. S. Bureau of Mines should he used. As a rule, it may he said that masks, respirators, or other such protective device should be used only where exposure to the dust is intermittent and brief, or where some unusual condition makes a more ade quate dust control impracticable." Dust Control Engineering and medical control arc the two most important factors in combating (lie industrial dust hazard. and are to a large extent complementary. lim/inerriini Control. As I.aura'1 has fated in a recent paper, "It is a basic principle in dealing with a dust hazard that she dust should be attacked at its point of vrigin and thus prevented from being dis`emulated into the atmosphere." After the dust lias been spread throughout the air it is difficult to deal w ith it, and reliance inii't he placed on individual protection, which is never wholly satisfactory. Lanza further cites various methods used :i controlling dust. These will lie reviewed out briefly, since a paper dealing with the object of dust control in detail, will follow jo this program. Where bacteria or other living dusts in the air are associated with a process, steri lization methods such as increased tempera ture, ultraviolet radiation, and chemicals like chlorine or other bactericidal substances, may he of use. Pasteurization temperature (about IdO* F.) will kill most organisms except those hearing spores. Steam disin fection is used for horsehair, and proves to be practicable if the temperature lines not exceed 2.10* F. Wool fibers, however, lose their elasticity bj steam disinfection, and the "1 bickering" process now ncd in F.ngland includes soaking of the wool in a form aldehyde solution, and drying in a rurrent of air at a temperature of 160* F.`: There nre few occupations in which there would he a sulficiYnt concentration of dead bac teria to cause untoward effects in man. In the ease of dusts producing external irritation, auxiliary protective measures may include the use of' protective clothing. gloves, goggles and aprons; as well as pro tective salves, ointments, or other coin pounds to delay or diminish the irritant action. General rules for hygiene and good housekeeping should also be observed. Medical Control. Equally important, and clo-clv interrelated with the engineering phase, is medical control of occupational hazards. In addition to directing the proper placement of new workers, and guarding the health of all employees, medical control is a check on the efficacy of the engineering control methods already instituted, or a mva-ure of the need for new protective de vices. It has been stated that "Industry has found that the best way to treat industrial injuries and illness is to prevent tlitNi,''M and medical control, through prccmplovmrn! aiul periodic physical examinations, is one of the most important factors in such prevention. The prccmployment examination is made to determine the employee's physical and mental fitness for work. It serves to dis close the presence ol any contagious dis ease. reveals any minor physical defects which might Inter become serious, or whetherthe examinee's condition precludes his,em ployment in certain or in all types of work. It should be remembered that such preem pt; ttient examinations arc not to lie made for the purpose of eliminating an employee, but rather for allocating him to the type of work for which he is physically suited. A 'worker should be given employment unless totally unfit, or unless his disability, even though slight, would cause him to be a haz ard to himself or his associates. Further more, the practice of prccuiploymcnt examinations^should be extended to include executives and officials of industrial organi zations. "The purpose of periodic physical examinations is to secure and maintain physical fitness and thereby lengthen work spans."* Reexamination of employees some times results in the discovery of defects and disabilities which were not observed at the time of employment. In such eases, an oc cupational adjustment should lie made to provide continued employment, hut remove (tie risk of permanent injury. Reexamination of employees is required by law in certain occupations in which the handling of poisonous or otherwise deleteri ous substances may result in the contraction of disease." f^iiicc sonic occupation.! eases tend to clear up and recur, reroi previous occupations should he inrlud the phy-ical examinations. The fnqi of examinations should he det'ennine the medical director, unless otherwise s fied by law. Those exposed to known < pationn) disease hazards may have wi or monthly examinations." "It should always he kept in mind that basic principle of physical examination industry is to keep men on the job and allow the physical examination to he me a weeding out profess."'1 References * m>liyM. J. ami Ii.ill.iV,It.-. J. V. " and C?*ntri| f Industrial S. Public Ifr:tfITi ItuHrlm No. 217, April. fVJL 9 CoUis, Killer L. "Indu-lciil PnritinnCOni'i with special reference to Di*f riithiMv" Mil Lecture.*, |015. II. M.S.O . London. * Sollmann. Toraht. "A Manual of Phan cnlmry." W. II. Sannderi (k Co., Philadelphia, IT * l airhaM, Lawrence T. "Toxic Jin*!* 1 Fumes.." Journ.il of lnfhistri.il Hygiene and To eolnev, November, 1936. 1 Bloomliriti. J. J. "Ttie Sampling and An.dv of Industrial Diutv" American Public Health A ci.Ujon, Vrirbonl;, 19)5-.V>. IP. M. Har.m| in fndmfry." Fro- IJenn, Ltd. I-orfInri, 1925. ^ I Air Kycicnc Foundation of Amcrir.i. Inc. "S* cod* and Allied Disorders." Medical Series Rid tin No. I. Pimboreh, Pa. Af>r| Kettle. K. Jl. "The Action of H-vnifnf Dint Jn*t. of Mining and Mctallirrcy, Lon *n# lout J m*. ` * "Diimj, Fumes, and Smoke*.'* Or upitinn a* Health Series, International Labour O Sce. t< tu * mo. , . . * Drinker. Philip. ''Causation of hicumnrnt oaij." Journal ol Industrial Jlygicii, and To eolocv. October, 1056. , II "Dyeing." Occupation amt Health Feu- International Labour Office, Geneva, FUG. VJ Lecce, Sir Thomas. "Industrial, Maljdi*' Oxford University Prcs, London, 19J*L ** Durstein, A. "Nicotine Action front lnh.il. Tobacco Dut/' Journal of Industrial H voicin'. I1 cetnber. 1927. li White, R. Proper. "The Dermitvf Occtip.itton.il Affection* of the Skin." JL K. Lv* & Co. Ltd., f.ondon. 19.U, ^ " Sebwarir. Lout*. "Skin Har.ird* tit Atiwri* Indu*tr>*." U- S. Public Health Uttllclin No. J) October, 1911. l* UrtH ttirijr, J. G. '*ft\diwtraf Derinato*'>: Ttr ment and Local .V-pcct%: Review of Kccent Lite- litre.'' Journal of )du~tri;d a Toxicology, July, 1955. t 4 tf "Occiipatiouaf f.c*ion in Worker* in Sitev Jlclcium Letter, Journal of American Medical A* ciatintt, Sej*t. 10. 19-*7. Abvt. Journal of li*di*U Jlvcirne. 1-ebrn.iM*. J9JS. _ "Flour MivM Ocrupalinit tn<l Hetbb Sen InterHJtioiial Labour Office, t*cn'v.i, J^IO. ,#Mavcr*. Mav R. ".Stiierprthibre rn fb-rtnitili' The Indtnirial lLtMctin, Albany, N. V. I eh. 19' vol. 1 ft. no. 2. ^ Drinker, Philip, and Hatch. Theodore "Ind* trial DiKt.'* Mcitraw-lltll Ilook C'oinputy, !' New York. I9if*. . u SchwartrK Lfi*. "Skin ILirird. to Amer* Industry. Part II." IJ. S. Public llralflt ftulb No. 229, Sept. l.K . c "Po*ottmii Wood*." Orettpatioit ami lira Series, lnicrnation.il Labour Oflice, Geneva 1930 a Hopr, F. W.. Hamij, H\, and Stallyhra**, C. . ''IndiiMn.il Medicine and Hygiene." flaiilicft, indilj and Cox, London, 1923. * Drown, Ct. T. "Tlie Diagnosis of llaclerial iler*y.` Southern Medical Journal, Vol. 27, No. 1. t>cr. 1931. , s Slier*. R. R. and Mcrcwellier, F. V. "Miliary me Pue to Unknown Came. U. S. I'ublic iralih Report*, Dec. S, 1930. M "ActinmnyfOMS." Occupation and Health Sen'c, ntcrnauoiial Labour Office, Geneva, J9J0. " Holland, J. W. "Textbook of Medical Cbemiitry nu Toxicology." W, B. Saunders Company, Phila* elnhia, 1920. " Bloomfield, J. J. and Blum. W'm, "Health Hat* *d* in Chromium rioting." U. S. Public Health -rvicc Reprint No. 12 IS, Washington, 1930. * Rmsell, Tone*. Bloomfield, Britten and Tbomp* n. "Lead Poisoninc in a Storage Badcrv Plant." '. S. Public Health Hullctiit No. 20$, June, 1933. ** Neal. Jones, Bloomfield, DatlaValte and F.4* \rd, "A Study of Chronic Mercuriali*ti in the f.ilicM* Fur Cutting Industry." U. S. Public 'alth Bulletin No. 2.14, May, |M7. ,** Saycr*. R. R. and Jmie. R.'K. "5dico*i* and Similar Dint Diicaie*." National SilifO'ii Con* fercncc, Waihintjion, P. C-, April M, 1936. ^S-iyen, Bloomfield, PaltaValle, Jone*, l)rer^cn, Brundagc and llritten. "Amhiaco-Sihcni among Ilarl Coal Miners." II. S. Public Ifcaltti Dulivtin No. 221. December, 193V >. Middleton, F.. !. "InduMriil Pulmonary Pis* eae due t< the lubalation of The Lancet, July 4 and II, I9J6. ,, H Dree*sen, Waldemar C. "Lficct of Inhaled Marble Oust ax Observed in Vermont Marble Finishers." U. S. Public Health Service Reprint No. 1630. " Lanta, A. J, "Control anil Prevention of Sili* cods/* Symposium on Silicods. California Tid-er* culom Association, San Francisco. 193*. H Neivquixt, M. N. "Medical Scrvieedn Industry and Workmen's Compensation Law." American College f Surgeon*. Chicago, 1934. _ ( w."Medical Care of lndmtri.il WorL*r." Na tional Industrial Conference Baird, Inc. New Vork, 1926. The Engineer's Part in Eliminating Dust Hazards By ARTHUR S. JOHNSON Assistant to Manager, Engineering Department,'American Mutual Liability Insurance Co., Boston, Mass. W lien one realizes that control of the dust .azard depends upon the combined coiitrilmons of the physician and the engineer, he aprecialcs that the solution requires scientific reatment. By scientific treatment I mean the cchnical analysis of the hazard to discover he causes which contribute to injury or ill :calth, and the development of control meth ods which obey physical law and physiology, nd which will lx: directed at causes that **-liiiit of most immediate and economical reatment. That goes for handling the dust hazard in ' "iven plant. It goes double for acquiring aiowlcdge to the end that the whole problem lay reach ultimate solution. Right now our nowlcdge of the problem is in big chunks, oosely put together and largely empirical. There arc estimates only to judge the maglitudc of the dust health problem, and it is so loselv associated with other health problem* dial a clean-cut estimate of it alone is imusiblc. Wc do know that it is great in the Sgrcgatc, and for the individual plant it may c very bothersome and expensive. H hat actually makes quartz, dust cause ilicosis is not known. It docs, so the air `ireathed by workmen must not contain harm 'll quantities of respirable quartz dust. Inex pensive methods for making tlie air clean are -till in the realm of dreams. Much work must lie done to know more about silicosis ami more bow to make atmospheres safe iiir.r/viish'cly. z\s an accident prevention job. dust control lies almost entirely within the admin istrative responsibility. Tlie control measures are capital expenditures of considerable size. A plant with a dust hazard is sick, it needs an expert diagnosis and scientific treatment, which may include expensive major opera tions. I foinc remedies arc seldom much good, and supervision and employee safety con sciousness alone cannot accomplish anything. There may be observed iigyountlcss shops installations for exhausting' dust which are derisively called "tin knocjtqr" jolts in which the horsepower dissipated is'out of all pro portion to the air-borne dust moved. Tonnage cllicicncy of material moved may be the proper yardstick for pneumatic conveyor- hut if the material to be moved is air, contaminated with nearly weightless particles of lust, the entire health hazard can lie in the half of one per cent of material not moved. I do not mean that unless a dust supression job was engineered it can be no good. There arc many good installations that were never figured at all blit grew likr Topsy. The re sulting freedom front dustiness was -o \ati-factory that efficiency held little interest to the owner. This is exceptional, however, and I offer the opinion that dust suppression jobs should he engineered. A dii-t-siippressiou installation is a safely desire, designed and operated to provide pro tection against possible disease and provide a sense of security which must be absolute. Its safety is not rushing air and rattling chips but a minimal' residual dustiness. There is no more pathetic defeat for a du-t control job than to find faith in its effectiveness so low that workers must wear respirators to find the rca-onahlc safety that was expected from the hoods, duets and fans. Diagnosis and Control l.et ii- examine some of tlie features Iiy which we recognize this dust hazard problem, leaving out tlie soeio-legal aspects. In order to develop more fully the engi neer's place in this du-t control program, il -ecu's desirable to separate as sharply as we can the diagnostic considerations from tlio-e which deal, with control. In the first com partment wc can place all the analytical com ponents which describe the hazard and its exposure,\hc probability of its producing ill health and all the rest of the mcdiral and industrial hygiene facts which make out a case against the existing dust. In the second compartment place the knowledge of physics and engineering necessary to plan the dust control program and so design it that when .installed its performance follows prediction that the probability of industrial disease is reduced to insignificance. The Industrial Hygienist Our first fca(ure of interest would uaturally be the specific and relative toxicity of silica, silica-bearing and other dusts which make up the dust health hazard. Much might be said to advantage about tlie quality and quantity of hazard in many dusts. The acquiring of this knowledge has been, and must remain a medical problem. It involves gross and micro scopic pathology and x-rays, and experimental animals. Engineers do not talk that language. -'Industrial hygienists do; they arc a happy combination, half doctor and half engineer. Many of them are quite capable of handling the dust health hazard in all its phases of investigation and control. For the purpose of this discussion I throw their interest in with the doctors. I want to g/> so far in ir:y opinion as state that the engineer .-lumlc not attempt define the quality of health hazard in a gn plant or industry, nor should ,hc estahli thre-hold limits of safe or permissible iluiic-s. This may he debatable, hut I shall o lend that the engineer who writes the spo firations of hazard and dust tolerance is real an industrial hygienist, and is using a sc much broader knowledge than cngineerli alone. In the fir-1 ca-c the quality of the heal hazard is an opinion arrived at aher sludyii all the environmental conditions inhaling t general sanitation, occupational a. alysis a a scientific analysis of the du-t exposur In flit* exploration of du-t exposures, t nature l du-ly operations mu-t lie view from physical, eheiniial and inerli.aiili a-pect-, the determinations of (lustiness mi he not only counted and rlas-ifird by partic late sizes, hut chemically and ruiucralogical analyzed. The plant layout mu-t be -Midi, with re-pcet to dust production and di-irili tiou, and the housekeeping and existing *lq control equipment evaluated. The presence specific hazards, such as toxic gases, alum mat temperature and humidity conditions. el> must lie explored for their c uiplicating cfTc upon the whole picture. This is distinct Iv a industrial hygiene job, and some of die um critical data requires only medical view polo This is absolute in the case of tuhvrculo. study and the qualifying of men for employ nicut. So far. not one atom of engineering i suppress du.-t is iiuolved. ft is entirely ana ysis of hazard. The diagnosis mu-t be th the du-tiness is hazardous to health or that is safe. If it is hazardous, it must be brougl down to a specified residue. If it isn't, Icai it alone. Oil the second point, if the hygicni-i can not specify threshold limits gradual' upwanI for relatively less hazardous dnsl let the engineer not worry about it. Th diagnosis is dust which is harmful and to much of it. The remedy is control of the dus The engineer designs controls which wi produce the lowc-t practical residual du.-i ness. He should not attempt to write his ow specifications of threshold limits or permi siblc (lustiness. This may lie an inqiortai goal in the study of dust health hazards. Safe Limits At the present time the medical men ai hygienists believe that quartz du-t is -ai below five million particles. They seem will trical phenomena which bear upon dust be ing In graduate upward to 20 million for havior. medium silica and 50 million for low silica Tlmst arc all principles of physics which percentages. Five million particles is virtually explain the behavior of dust'pml upon which dust free, and is very difficult and expensive engineering practice must be based. They In achieve and maintain. The declaration of must be understood and be taken into account. saiety of the installations must remain in the . Dust control is not a matter oiil) of general hands of the medical and hygiene groups in vcutilatmn; the engineer must study the pro whose hands now lies the responsibility for. duction as well as the dispersion. The problem determining the hazard. should he analyzed to determine the applica We now enter the chapter of our discussion bility of Segregation, enclosure, wetting, local intended to demonstrate that dust control is exhaust and general vcntilatioip an engineering job, that it must be given scentitic treatment, not guess work, applying engineering methods which arc based upon a know ledge of physical law, the behavior of dust, the perfoymancc of air-moving machin ery, etc. In some instances, substitution of nuti-hazardotts material, or non-t|ust-produeiug oper ations may have specific application, and they should be explored first. This implies plant engineering. 1 am convinced that many bail installations arc bad because plant engineering Prerequisite Knowledge was not used. In (lie designing of exhaust systems installed to capture the dust at the I.et me recite hriclly, a few of the things which, in my opinion, the engineer should know to do this job correctly, fie must know bow to make a survey. Surveys depend upon sampling, and sampling is not a catch-as- ratcli-can proposition. It involves the place, the time, the frequency, the amount in a sam ple. and the number of samples so that maxi mum. ininimmn and average data mean some points of generation, the physical behavior oi air moving toward hoods and in ducts must he known, and that knowledge used, leach system must consist of collection hoods, pip ing. air-cleaning plant and a source oi suction. Before selecting a hood for a job the engineer must know dust dispersion by dynamic pro jection as well as dust dispersion by air cur rents, and design the hood accordingly. thing. Mi that credibility can be given them. For the type of sample involved be must Knowledge Needed know how to weigh or count respirable dust, The acro-dyuamic characteristics of suction as distinguished from large masses of lion- hoods appear to be little known because little respirable dust which complicate the picture, thought was given to them in designing lie must know how to observe the sources of thousands o( hoods which can be found every iltist floods as distinguished from conditions where in industry. All the possibility for of normal dustiness. Me must know the entrapping dust and much of the efficiency oi sources of dust and the principles involved the system lies in this fartor. Air velocity, in the dispersion of dust. Ife must determine static suction, and rate of air flow arc all how much dust enters the problem because it related, and they must he known. It is essen is part of the material, and what dust is tial to use high velocity of air in certain types created in the process by the fracturing of the td exhaust systems to entrap dust projected material. at high velocities as in the case of a granite Any less survey cannot tell the engineer surfacing machine, and low velocities must he what bis task of dust control is. To visualize used in others, as in the case of cleaning that task intelligently he should know the asbestos fibre of dust to prevent waiting physics of Brownian motion, laws of ri-sj-t- material. aoee to the mution of particles moving in air. Quantity of air and its velocity must he both when the air is in turbulence ami for determined, then the piping should he de stream-line motion. He should know terminal signed to lake into account the behavior oi velocities, movements due to centrifugal mo nir-llow through pipes at low' and high veloc tion; flocculation and the effects of air motion ities. Where the problem is complicated by an<l the effects of humidification bn it. He the large sized particles which go along with must know all about the difficulties of welting (he- fine dust, how these behave must be taken and what is known about overcoming these into account. Pressure losses are very impor difficulties. He should know the several elec tant dements in the design of an exhaust system. I.oss at die hoods, loss at the bends, and loss in the ducts must not be guessed at. Pipe design must take into account the gage of the metal and reinforcing to withstand pressures and erosion. The selection of a fan and its motive power is a mailer of calculation, not guess work. Power consumption in the system is calcula ble. fans follow certain laws, so the engineer must know the behavior of axial flow, pro peller type, radial flow, paddle wheel and other fan performance. More physics and engineering calculation goes into the air-cleaning apparatus. The selection of gravitation, inertial or filtration method depends upon what the dust is, the calculation for any methods requires knowl edge of discharge through stacks, the deter mination of sizes of settling chandlers; the behavior of cyclones. The use or non-use of a filler, and if so, what type, how it should perforin, how big it should lie. wliat kind of resistance and how much each kind offers, to say nothing of their proper location with relation to cleaning, accessibility, etc., are all items for accurate engineering determination. Apparatus to check the beiiavior of iustalla- V lions must be known and used.' Pciiofiuui cannot be left Ri guess work.' Supplying mi cicnt air to be exhausted is part of the pn lent. The same may he said of heating Do f give the problem too severe a hm up? I think not. Remember diesc two lliim 1. Vou are dealing with hazardous nu rial so small in size and so little of it weight that it is as invisible as the air ll hears it. . 2. Physical laws involved in the beliav of du-t and air do not permit incxpviiM methods of control. I ant acquainted w budgets set up for this purpose which anun to more than a quarter of a nv'lioii dnlla and l know of many where 60 tc 80 tlum-a dollars is involved. The need for this much cngincc ing is ri ognized by men who know. Ah ady mu has been done toward getting the know led into handbook shape. Perhaps the he-t j of this sort to date is "FtmdameirnN Relate to the Design and Operation jf F.xliai Systems" developed under Amcr.can Stan ards Association procedure. The Doctor's Part in Controlling Dust Hazards By A. D. LAZENBY, M.D., F.A.C.S. Chief Surgeon, Maryland Casualty Co., Baltimore, Maryland Considerable confusion has existed in the past as to just what is the physician's func tion in the prevention of dust diseases, and just what is 'the engineer's. It is very ob vious upon even casual thought that the two sciences must work hand in hand in their eflorts to solve the problem. The physician through his special training must be able to tell the engineer what dusts arc dangerous ami what are out. He must know liovv those dusts enter the body and the manner in which they do their harm. He must be trained in the examination of per sons who are to be employed to work in dust, and to discover those who arc already diseased, or arc peculiarly susceptible to dust disease. He must be able to detect the first signs of disease in workers who arc exposed to dust, and must be prepared to recognize the disease when it is I idly <h vclopcd. . It is not necessarily the physician's fum tion to analyze dust. That is a task for ll chemist and the petrographer. It is not ll physician's function to count the particles < dust in a given industrial atmosphere. Thn in reality, is the function of the engineer. 1 is not the physician's function to devi- vcntilating equipment for the removal < dust, nor even to he more than an advi-i as to the means that must lie adopted t render the atmosphere safe. The physician nevertheless must correl.n with his medical knowledge and with h studies of the imhi-trial worker the fimfin of the engineer. A diagnosis of silico-is. (< example, requires not merely charactcrisr occupational history and characteristic phj - i ll findings, bul lilt knon ledge as lull that We have nu real know ledge as (u true I ho patient lias been exposed to hazardous figures, but as a simple rule, wc can adopt du-ts hi dangerous concentration*. v for practical purposes the thought that the Alt dusts when inhaled in excessive human body can withstand successfully a i|iianlilics may be considered as harmful, hut couerutrntion of dust cunlHriiiing 100 per cent only a few can be regarded as dangerous. silica ilioxidc in a particulate size less than From the standpoint of their dangerous 10 microns, in a concentration not in excess properties, they may he dii ideal into three of 5,000,000 pat tides per cubic font. If wc general groups. , decrease the percentage of silica dioxide 1. Tlnisc which arc dangerous because of their poisonous action, such as h ad, arsenic, meremy, and similar snhslaiiees. present in the dust, we ran correspondingly increase the eniircutraliuii with comparative safety. Wc must, of com sc, take into ar count the portion of the worker's time spent 2. Those which cause only irritation in the respiratory tract, resulting in such condi tions as bronchitis or local inllammation; such substances as vegetable fibre, cork dust, Hour, starch, and other relatively innocuous organic or inorganic materials. 3. Those which tend to produce fibrosis ot the lungs, thereby predisposing to respira tory in lections, especially tuberculosis, such in the dusty atmosphere. To arrive at a rough conception of a safe atmosphere, we multiply the percentage of free silica in a given dust by the total num ber of particles per cubic foot. If the result is under 5,000,000 the condition may he con sidered relatively safe. If the result is over 5,000,000 the condition must he regarded as unsafe. dusts as asbestos, silica dioxide ur mag nesium silicate. I shall confine my remarks chiefly to dusts occurring ill the latter category. Hear in mind loo that silicosis i- essentially a disease of great chronicity. Except in a few exceptional instances it will require from seven to thirty years for a worker to It has been generally believed that the develop advanced silicosis. It is evident too harm lid clTccts of dusts inhaled into the that coincident dusts may cither retard the longs depended more upon their physical structure than upon their chemical. It was believed, for example, that silica dioxide, or quartz, was particularly harmful because of its crystalline structure, and the hardness and sharpness of its particles. This concep tion is now known to be faulty. The dusts development of silicosis or hasten it. Recent research seems to indicate that the admix ture of aluminum dust to a silicious dust will greatly inhibit the reaction of the latter; whereas a silicious dust combined with some alkaline coincident dusts may hasten the de velopment of silicosis. which cause their damage by mechanical in Much research is now under wav in prob terference with function arc the dusts which lems such as this. Wc have never learned how arc relatively innocuous, whose symptoms to cure silicosis, but wc are learning rapidly are transitory, and which subside upon re how to prevent it. Our knowledge in this moval from exposure to the dust. respect seems to he limited to the removal of Chemical Effect Is Harmful dust from the breathing zone of the worker. Later discoveries may show us how to The disease of particular interest to us miodify existing dusts with contaminant today, silicosis, owes its harmful effects very dusts that will render silica dioxide innocu largely to a harmful chemical reaction oc ous. . ` curring between silica dioxide and the body tissues. It so happens that silica dioxide is decidedly a tissue irritant to the body, re gardless of the part of the body it invades, it causes local irritation, local destruction of tissue, and the replacement of that tissue bv scars. Thus, given a dust containing silica diox ide in sufficient concentration, in sizes small enough to permit its entrance to the ultimate Owing to its very great chronicity, it is only the rare case who actually develops disabling silicosis during his industrial life time. It is realized, of com.sc, that excep tional instances lake plate, hut the coincident ravages of age usually keep pace with the effects of dust, so that much r't the dis ability usually attributed to silicosis is often, in fact, actually attributable to other dis eases or incapacities which advancing years air spaces in the lungs, we have a situation bring in their wake. To me the great peril of which offers danger to the worker. silicosis, the peril not only to the industrial uorker himself, but his family, co-norker* and the public generally, is the accompany ing .susceptibility to tuberculosis. Complicated by Tuberculosis Silicosis per sc docs not kill. Tuberculosis as a complicating factor of silicosis rarely recovers despite treatment, and the indi vidual so afflicted is not only totally dis abled bim'clf, but n definite menace lo all with whom he comes in contact, particularly the fellow worker who may have silicosis. So pci haps the most important places in which the services of the physician in a dusty trade arc necessary arc--first, along lines of discovering and barring from exposure to a silicious dust those persons who may al ready have arrested tuberculosis; and sec ondly. discovering those persons already ex posed to dust, possibly already silicotic, in whom tuberculous infections may have de veloped. It is well rccocnizcd that tin individual should be exposed to dust containing silica dioxide until lie has undergone a thorough physical, examination, including carefully made and interpreted x-ray films of his chest. It is likewise obvious to anyone fa miliar vlith silicosis that no person who is exposed to silicious dust should be denied the privilege of frequent physical examina tions and x-rays of the chest, not entirely to discover the existence of possible silicosis, but to discover a coincident tuberculosis if such exists. A man so diseased should, in protection to himself and to all with whom he conics in contact, he removed from industry. Let me emphasize the uselessness of a physical examination, unless it be accompanied by properly taken x-ray films, except in rases of gross tuberculosis. It is llic function of the physician, there fore, to conduct in a thorough and an intelli gent manner the prc-einployincnt examina tion ot all persons who are to be engaged in a dusty trade. The purpose of this ex amination should be threefold. First, to discover and bar from cinploj merit in dust, any person who is suffering from tuber culous in an active, a quiescent or an ar rested state. .A possible exception might be made in individuals suffering from a so called healed primary complex, or a healed childhood in fection. It is well known that exposure to silica dioxide is vet) Id.) Ii `to esirile activity a liir'ficrculoiis li -ii-u uhuli nu ipiie-cent or arrested, and n> c -urI, a |( is tv activated, the i hance- ot uvnvcri remote. . The second problem which confront, physician at the prc-cmplov ment pliv-ica animation is whether a given imhvidn. by reason of secondary physical del more susceptible to the development of cosis than a normal. Is lie suffering f diseases of the nose or upper rrspira ti act, such as chronic sinusitis, disease o lungs or air passage*, or obstructions w produce mouth breathing? Wc must remember that silica dioxii not dangerous until it reaches the lungs, that the normal individual retains in nose and the upper air passage* a I quantity ot (he dust inhaled from tfic at phcrc. In instances where this nasal r< lion is disturbed, exposure to silica die dust may be dangerous to that indivi where it would not he to another. It is believed that certain diseases ni heart and circulation, of the kidmvs, p hly syphilis, chronic coincident disease the lungs, all may render a man more ceptible to silicosis than normal. The pi cian at his pre-employment examination i follow certain established criteria m respect, and liar from exposure to d.mgc dusts llipsc persons who through c.xis disease may be more ready prey to silic or tuberculosis. Re-Examination Needed After the applicant for cmplov incut successfully passed his physical vxamiua and is engaged in a dusty trade, the < of the physician is not yet ended. This w. man must be periodically rc-cxamincd. to discover the early appearances of nionnry fibrosis, but what is even more port.mt, to detect the early evidences complicating tuberculous infection. A man should not be dismissed from ploymcnt in a dusty trade merely hecaii' has evidences of non-disal ling silic Workers in dusty trades, especially s cutters, moulders, pottery workers, similar craftsmrn, ate usually ..ighly ski and it .seems unfortunate finin' a 'nria! economic point of view to dn.y tin m plo) incut so long as they are plivsfiallv to carry on. especially since the actual abling qualities of silicosis arc in doiilu Tmiily-sijrtlt Xalinna! Sofely Congress They should iic denied employment in a lusty trade it that condition is found at pre-employment examination, hut they should not be barred from continuing an employment in which they are already en cased. Of course, in such instances you. as engineers, must realize that you have failed, because if you had kept the breathing zone of the worker free from dangerous dusts, silicosis would not be present on physical examination. In this work of preventing dust diseases in industry, it should be evident that the closest and most intelligent cooperation between the physician and the engineer is necessary. The physician must, through his knowledge and research, tell the engineer what dusts, or. for that matter, what other substances used in industry are harmful. He must tell the engineer how such dusts or other materials enter the body, how they leave the body and what they do in their passages through or their residence in the body. Must Make Analyses The engineer must in turn tell the physi cian of the harmful /dusts and other sub stances surrounding his .workers. He must make chemical and petrographic analyse* ot the dust*, and other indicated analyses of the atmosphere in the workshop. He mut make lust counts urn! check his counts at regular intervals, conferring with the physician in an effort to discover whether, in the light of their joint knowledge, working conditions arc dangerous. He must develop and install carefully designed ventilating equipment. He must arrange tor modification of chemical and other industrial processes, where such modification is possible, and must bend his efforts toward removing from the danger zone of the worker the offending substance, whatever it may be. Too many engineers construe this function loosely. They pass on to the physician as his responsibility certain functions which es sentially arc theirs; such functions as dust analyses, dust counts, and similar technical duties. All too often it is considered ade quate merely to install a tan. Ventilating devices in dusty work rooms must he constructed only after careful en gineering study has given a knowledge of the physical properties of the air and of substances polluting it. It is possible to calculate to a vert" tine point the volume of air that must be removed from a given spot trr-removc the dust originating at that place, anti the engineer mast approach his task "from just as scientific an angle as the physi cian approaches his. 'j There is no room in industry tof hap hazard methods on the part of either the phy-iemii or the engineer. ADJ 01) A'.Y ME .V T .y checked and rc|iairccl t>nc. and e will give it v.ition. In addition. 1 sug11C a man from each dou him in to <>nr ^atety ;s. rotating these men so !>iallv have them all meet .g these men a closer inetv work and permit ns to Mso. I will, until further s.v meetings with all the we can make clear the adat you men must assume, e to see that your men are mtr safety rules and the employees. We can also lividuals who do not Seem one hundred per cent. -.fety Work?' iephone Co., Chicago > difficult problems facing rn to the foreman his re ar safe doing oi the joh measures, we have taken :lc must feel that the '.He his res|K.ii'ihilIty and feel to do something about it. i' there an accident on a sidcrcd .particularly haz- '(line that the foreman or imw to conduct the work e sure that lie does ami I a proper training pro- nie that a majority of all accidents arc directly or ile to tlie failure of supervel to function properly, that supervisory training ing accidents is necessary. of a supervisory training more dillicult procedure it of a technical or vocng;. Apart from the tecli.cd. there does not seem formula. There is, of Cemciit and ()mirr\ Sections 2 57 course, some similarity of procedure in di recting die work of any man on any joh: but different industries employ such different types of people, under such a wide variety of eirrumstanees. and place such a diver gence of rci|iiircmrnts upon them that the problem of supervisory training in its more comprehensive aspects is peculiar to cacli type of industry. The general treatises on leadership give tite groundwork, but the subject matter for any supervisory training course lor any par ticular industry lies within that industry. We must go out and see Imw our job is being supervised now; analyze the procedure of every foreman and supervisor: compare them and .select the best: look u|>u supervision as a process in itself, and see how best to direct the work of the people. It is a long, tedious, ami costly process. Imt one which, carried flirriitiifi to completion, will pay dividends in the end. WEDNESDAY LUNCHEON SESSION October 13, 1937 The Wednesday Luncheon session of the Cement and Quarry Sections was addressed by Isaiah Hale, Superintendent of Safely, Atchison, Topeka and Santa Fe Railroad, who spoke on "The Common Sense of Safety.'' The address was substantially the? same as another address by Mr. Hale before the Steam Railroad Meeting. The complete paper will lie found in the Steam Railroad section of this volume. . WEDNESDAY AFTERNOON SESSION October 13, 1937 . Work of the Nations! Silicosis Conference By R. CAMPBELL STARR Assistant Safety Engineer, U. S. Department of Labor, Division of Labor Standards, Washington, D. C. Silicosis is strictly an occupational disease. Medical science lias not reported silica dust as affecting any individuals except those who, over relatively long periods of time, have worked in an atmosphere where the air which they breathe contained excessive con centrations of free silica. The interest of the U. S. Department of Labor in a broad social and economic prob lem such as this has its origin in the Organic Act, elfectivc March 4, 1913, which created the Department. This act, among other things, gives the Department of Labor the fluty "to foster, promote, and develop the welfare of the wage earners of tiie United Slates, to improve their working conditions, and to advance their opportunities tor profit able employment." With this in mind, and believing that through joint effort of all concerned, much could lie done to eliminate the hazard, the Secretary of Lalior called together in Wash* '4* t! l i 11 iiiglon on February lit, I9J0 a group of visors, one oil labor problem.' and one on al)i)ii( 75 invn representing leaders in iiiilos- v mining matter'. tric-s having a silica problem, labor leaders and outstanding representatives of the medi I liesc committee iiieinher' 'erved without cal. legal, and engineering prol'essions, as compensation and gave freely of their lime well as insurance carriers and State adminis trators. and cltort in studviug the problem from their respective viewpoints. After nine nmnllis of careful and searching sliidx; these commit After considering various phases of the tees advised the Secretary of Labor that silicosis problem, Ibis group generally agicrd they were ready to repot I. Coiiseipieiilly. that through a pooling of knowledge and a on I'chruary .1. I`.>7 die Second .National Irani, di-cn-sion through the coulcicmi: Silicosis t. onfcmii'c was called ill Washing metboil important advances could be made ton. At this time summary committee re toward, first, overcoming the hysterical at ports were presented to the Secretary and titude on the part of employers, labor, and Considerable discussion was given them. others; second, after careful investigation, to consolidate in one place all known data with regard to the preventive engineering methods; third, analysis and recommenda tions in connection with adequate standards of compensation for those workers disabled as a result of the disease. ' Shortly after this second national confer ence the Department published, as l!iillelin No. 1J of the I tivisiou ol Labor Standards, the summary reports of the lour committees referred to above, together with an abstract version containing the principal findings and recommendations written in imn-tcchnical As an outgrowth of this initial meeting, language. another group, similar in composition to the first conference, but expanded to include some AH) individuals, was invitvd to come In Washington on April 14, 19Jb to outline ways and means of attacking the problem. After bearing silicosis discussed from the stand point of .the employer, labor, ami the medical 1 lie full reports of the committees, com prising several llioiisnnd typewritten pages, are nhw living edited and will go to the printer very shortly. It is expected that they will lie issued in four separate volumes sometime (luring the fall or earl) winter. profession, by outstanding experts in the field, this large group endorsed the confer Nature and Extent of Silicosis ence method as proposed, and as a result four main working committees were ap Physicians generally agree that silicosis, pointed by the Secretary of Labor with (lie in the layman's language, is a disease of the advice and consent of the group to invcsli- lungs, caused by breathing air containing -ntc and report upon the outstanding phases silica dust, in which the normal long tissue of the silicosis problem. These committees is replaced by fibrous or scar tissue. were: Silica dust is found in many industrial operations, but the hazard is acute only in (1) Committee on the Prevention of such industries as metal mining; anthracite Silicosis through Medical Control, mining; quarrying, drilling, and tunneling in (2) Committee on the Prevention of granite, ganistcr. and sandstone; smelting Silicosis through Engineerin'* Control, and refining; foundries; potteries; glass (J) Committee on the Economic, Legal works; stone-products industries; grinding; and Insurance Phases of the Silicosis hulling; and sandblasting. Problem. (4) Committee on the Regulatory and Administrative Phases of the Silico-is Problem. Of the 40,000.001) workers in the L'nilcd Stales, only 1,000,000, or 2 per ronl, it is es timated, arc in any way exposed to the haz ard of silicosis. About ball of this number, or 1 per cent of the total mimher of workers A fifth committee, known as the Correlat in the country, are exposed to a serious haz ing Committee, was named. It was under the ard, and approximate!) 110,000 of these have chairmanship of \V. H. Cameron, Managing silicosis in some degree. Medical examina Director of the National Safety Council, and tion `uf men actually at work indicates that consisted of the chairman of the four tech bet ween 4,000 and 5,000 workers arc seri nical committees just mentioned and two ad ously affected hv (lie disease, in addition to I hose already permanently detached from their employment by reason of disabling sili cosis. ' The status of the 1,000,000 workers ex posed to the hazard of silicosis was analyzed thus by the committees making the survey: A percentage of the 4,000 to 5,000 workers having silicosis arc completely or pai liallv disabled because of this disease ami have their dil'lii ullics further com plicated with liihciculosis. The remainder of the 4,000 to 5,000 have silicosis and disability in some degree, hut no tuberculosis. Approximately 105,000 have silicosis, hut no disability and no tuhe.rciilosis. Approximately 900,000 arc exposed to silica dust, hut have not contracted the dis ease. Contrary to popular belief, silicosis is slow to develop. Usually it takes seven years or more of exposure to silica dust for a worker to contract the disease. A few rases that have been known In develop in ns short a period as one and one-half years occurred under extreme and unusual conditions." On the other hand, many workers have labored iimler ordinary exposures to silica for more than JO )c:irs without demonstrating any trinihlc whatever that could be diagnosed as silicosis. gineers, insurance companies, legislators, a miuistrators, and others. The reports of the conference' cniuliiillc on engineering control and medical toiilr recommend specific procedures for altac ing the problem through those two avrmi of prevention. A partial list of these rccon inrudatiiiiis follows; Survey the working conditions In dele mine llic severity of the hazard and iml vale w hat needs to he done to leerea<e i Secure information on best p peednre. Design plant for (lust control-'l'rovidc building ventilation. * Store dusty materials in dusttit 'it bins. Enclose material-handling equipment. Isolate dusty processes. l'rovidc wet methods of opcralion.- W'atcr, oil, ami other liquids may lie use effectively-- 1. To suppress dust at the point of oi igi in such operations as rock-drilling; hni dling, pulverizing, and milling rock an ore; grinding metal on grindstones abrasive-wheel cutting of granite and sand stnnc. . 2. To prevent the redi'persiou of >lu(hat has settled on the Ilnurs, walls, am oilier surfaces such as in the granite in dii-try aiql in foundries. Silicosis Prevention ' Silicosis can lie prevented in three general ways: First, by preventing the creation of silica dust; second, by preventing the dis persion of (lust into the atmosphere of a working area; and third, if it is impossible to apply the first two methods, by the use of personal protective equipment such as respirators, to prevent the inhalation of the dust. . In carrying out a prevention program, many agencies must cooperate. In the view of the committees studying the problem, the employer is called on to do most of the vvoik and to spend most of the money. Hut his work and money will never accomplish the maximum results unless the worker is will ing to cooperate and carry his share of the responsibility for helping to control dust and for using the personal protective equip ment. Design equipment to control dust. Establish good maintenance and house keeping procedure. Provide respirators. Instruct the workers. Responsibility of Workers The cooperation of the workers is neecs sarv if the hazard of silicosis is to he re (lured to the minimum. The worker slioiih realize that the safe practices rcrnntmcndc< and the equipment provided arc ( csigntd t< prevent injury to himself and to his fellow employees. The equipment should .<e used a directed and every effort should h.- made l< maintain it in good working order.'Further more, the worker is frequently in a po-i lion to observe faulty equipment and uiisafi practices, and lie should make it a point t( report all such conditions to his supervisor. Statutory Regulation In addition, physicians can play a definite While the primary approach to the proh part in preventing*silicosis, as can also en lent mii't he the prevention and diminution 260 / a'ciily-sixllt 'Yalimial Safely Coiujrrss of the hazard, tlie fact must be recognized that until silirosis has been wiped out. workers who now have the disease, as well as those who may ronlrncl il, must receive workmen's compensation just as do those workers who ate injured in accidents. Accordingly, the committees of the silico sis conference wore unanimous in presenting the following recommendations: Coverage for .silicosis in the compensa tion acts of all States. This coverage should be compulsory. Because of competition between the same or similar industries in various States, the laws, rules, and regulations of the several States should be as uniform as practicable. Should Be Insured . The employer should insure his obliga tion for compensation cither through self insurance subject to the posting of adc quate iunds, or with an authorized in surance institution. Insurance should not he denied any em ployer. provided the State authorities certi fy that he complies with the State require ments as to proper safe working condi tions, and pays the premiums involved. Workers having active pulmonary tuber culosis and silicosis should he removed from employment. Such workers should he granted suitable compensation payments ami mediral care. Workers disabled from silicosis (Inti with no tuberculosis) should ultimately he granted the same amount of compensa tion as those disabled by accidental in jury. Two years i* a reasonable minimum limitation period for tiling claims subse quent to the dale of the last exposure. Further Activities of the Department of Labor In carrying out its duty as stated in the basic law, the l'. S. Department of Labor has conceived that there is immediate need for the conversion of known facts in the medical and engineering fields working toward prevention, and in the legal, insurance and regulatory phases looking toward ade quate workmen's compensation, into a prac tical. readily understood program which will adequately take care of the silicosis prob lem. fit its program of cooperation with the IS States, the Department of Labor lias in cluded a section covering silicosis and simi lar dust diseases. This breaks down into three main sub-headings: (1) Assistance in the preparation of reasonable and adequate codes, rules, and regulations prescribing methods of prevention; (2) assistance in the establishment of equitable standards of workmen's compensation for those em ployees disabled as a result of the disease; (3) a general educational program among State officials, factory inspectors, etc. so that they will be equipped with adequate knowledge concerning the disease, its method of prevention, and its proper treat ment under the workmen's compensation law'. Follows Two Lines This application program, which is just now getting under wav has been commenced along two principal lines: (1) The compiling of practical information concerning actual dust control installations in typical silica hazardous plants, together with approxima tions as to cost, not only of installation, hut also of maintenance of (lust control equip ment in such plants; (2) a program of visual education supplementing the summary and full committee reports of the National Sili cosis Conference. It is contemplated that in tins liehl such media a- film strips, lantern slides, po-tcrs, illustrated bulletins, etc. will he utilized. Further, in connection with the various exhibits of the department, shown at various large expositions, trade association meetings, labor and technical organization meetings, etc., il is contemplated that much factual information will he used, pointing toward ways and means of correcting the hazard and of establishing adequate stand ards of workmen's compensation. Following the address bv Mr. Starr a hazards in quarry operation took place. This round table discussion of outstanding concluded the Wednesday program. Steam Railroad Meeting WEDNESDAY AFTERNOON SESSION . October 13, 1937 Tlic session wa* called In order l>v \V. \V". more, Md,, who presided, introducing the Wood, Ballimorc and Ohio Railroad, Balti speakers and directing the discussion. The Past, Present and Future of Railroad Safety - By J. M. SYMES Vice President, Operations and Maintenance Department, Association of American Railroads, Washington, D. C. .y No industry in the world requires more pcndability; grades and curves have been diversilied study and more exacting applica- eliminated or reduced; signal systems have lion of safety principles than the steam rail been modernized and extended; other safety road industry. Picture a quarter of a million clcvicrs have been installed; new and more miles of railroad line covering in a virtual powerful locomotives, cmhracing all modern network the vast expanse of the United safety devices, have been purchased; new Slates. Over this network are operated a cars, both ircight and passenger, have been . billion train miles annually. Vast yard and installed. Tbis capital improvement program i terminal operations arc necessary to make up lias cost the railroads about eight billion dol the beginning of the journey of passengers lars since 192J, and a large part, if not all, i and goods, and to break tip at the end of that of that huge sum had a beneficial effect, di ' journey the 12 million trains that accumulate rectly or indirectly, on the safety of opera that billion miles. These trains carry 500 tions. million passengers and one billion tons of But the engineer's job is ntvr done. As freight annually. It requires more than one soon as new equipment, new rail, or other . million railroad employees to run the trains. devices aic installed die engineers go to make them ready for road movement, stt- work to develop more efficient and safer I pervisc and safeguard their movement and units. The railroads spend millions of dollars maintain the equipment and roadbed, as well annually in research and laboratory work j as perform the many other duties incidental experimenting with engineering improve to the production of railroad transportation. ments. In all this work safety is of primary Safety has in the past, is today, and always importance. An invention which might mean 1 will he the first principle in railroad opera- great economics to the railroads would not t lions. P,ut it is within the past fifteen years find its way to a single locomotive or car . that greatest advances have been made in if its ttc in any way lessened the opportunity '> railroad safety. During that period we have for safe operation. Conversely, any improve ! seen a complete remodeling and modcruiza- ment, mechanical or otherwise, promoting i lion of railroad physical properties. Road- safety of operation immediately commends j beds have been strengthened; bridges. itself to railroad officers and employees. The trestles and culverts rebuilt; tracks have search for greater safety will continue so | l>ccn laid with heavier rail and with long as railroad transportation is used. ; treated ties of greater service life and dc- About a quarter of a century ago, the 5S7 i1 .1 .)' i- j. j kji.. ' !t ` * urn, iij x zzi ir/i W$: . .. iKarc _ jCnscl: tf&'pxz, =r-:T- .lii^eaa t: !<;> jyym T*> V^'Ssc >:-7'i -->t ;.C2li^C7 wrk. vcfFiz5h3 wrvj '^*tfac. rev: TM#: 'Jtc r =;5 he 1Wrv Ycu --ait jrUua se career -^pnfflc=?iy t- ^nfiTwwi;nlv trg> c^f n:"'J. set se repeated runal cisr. si.:d: aK<or ase. ' ay -geytrar same old ~ tpea aod c.-irig Straw luulriutd Mrrliiit/ 1 THURSDAY AFTERNOON SESSION ' October 14, 1937 ,V>3 Safety, An Executive Operating Problem By R. C. WHITE Assistant General Manager, Missouri Pacific R. R., St. Louis, Mo. Safety is an obligation of management. Without the constructive leadership ami dayto-day urge from the executive and operat ing heads, the movement would lapse into a perfuntory activity. The safety movement is recognized liy executive and operating officers as a medium for building up and maintaining that rela tionship, that fellowship, which broadens our views, enriches character, and brings the Golden Rule into practical application. Management recognizes that our economic system must.enable mgtt to live on an.in creasingly high i3hnc. :.ft must enable them tu fulfill their desires and satisfy their rea sonable wants, antrgivc them that feeling of security which is essential to happiness and efficiency. . Having made the decision that safety is an executive problem and responsibility--that accidents must stop--it is then essential that management promulgate, and follow through, a plan that will definitely fix this decision in the minds of all the individuals who collectively comprise the industry. The follow through must be such that department heads, superintendents, am! every member of the supervisory force will appreciate the need for a constant, active interest in safety; will understand that passive interest will no more produce results than would the same interest in production. Supervisors must be made to feel that the prevention of accidents demands the same type of hcads-up super vision that is given to the other problems affecting cost and service. The executive must find a wav to indicate directly that it is the responsibility of the department heads lo carry out management's program, that authority is placed in each superintendent's hands to put accident pre vention on the same basis as production. A complete.factual and descriptive report of each accident must be made. This must be followed by a thorough analysis to find the direct and underlying causes and the pro cedure necessary to prevent a recurrence. Proof of its sincerity will depend pri marily on whether management will make the first essential move in the program-- that is, authorize the expenditure of money necessary to make the maintenance and op erating plant a safe place to work. Safety and Efficiency Analysis of the underlying causes of in dustrial acridents and preventive measures to be applied has made it. increasingly appar ent that those factors which are producing accidents arc very largely the same factors which tend to lower the quantity and quality of production. Expressed in another way, safety and efficiency arc as inseparable as though one word. * In coupling safety with efficiency I have not minimized it as an executive problem, but have endeavored to indicate that its solu tion is an executive responsibility, both to his individual industry and to the employees that make it a going concern. Rail transportation is a scientific business in which laboratory research, expert engi neering, trained builders, and skilled workers share a part. One of the main factors is a group of employees who are loyal--who appreciate that their railroad must give the kind of service that will stimulate and accelerate the development of the territory traversed. The successful solution of our problem de mands the type of aggressive individualism in executive leadership that will attract and command loyal, collective , cooperative effort on the part of all who produce rail transpor tation. . Our major concern is leadership--Icader- H *f ; r. I ;; -. * .. )