Document 4vXYEk78MNEGkLLXjnM8Dv52Q

FILE NAME: General Electric (GE) DATE: 1933 DOC#: GE022 DOCUMENT DESCRIPTION: Transactions of the National Safety Council I 1933 TRANSACTIONS National Safety ) ; I I I Council i t I Incorporated f. tr TWENTY-SECOND ANNUAL SAFETY CONGRESS Si ta Chicago, Illinois I % i October 2 to October 6, 1933 A: j The Stevens Hotel V* t Copyright, l'K il, X n lio im l Sajcly Council, Inc. Plan of Publication T H E T R A N S A C T IO N S of the T w enty-second Congress of the National Safety Council are published in two vol um es. The first, containing the General, the General Subject, and the Industrial Section sessions, is supplemented by a sm aller volum e con tain in g the session s of the Street and H igh w ay Traffic Section, the Child Education Section, and Hom e Safety. T H E L A R G E G E N E R A L volume is being sent automatically to the Industrial members of the Council; the smaller volum e is sen t autom atically to m em bers who are be lieved to be chiefly interested in those sessions. It may also be secured on request by other Council m em bers. T H E P L A N OF P U B L IC A T IO N is the sam e as that adopted for the session s of the T w en ty-first Congress and found to be very satisfactory. It is a condensed rec ord. The papers of each session or division of the Congress have been assembled, edited with care and discernm ent to ab breviate or delete the less essential portions, and the concise re sults are presented for study and reference. Although not "com plete" in the sen se th at every word is reproduced, it is a readable, interesting record w hich em phasizes the memorable parts of each paper and address. T he original manuscripts are on file in the Council Library, available for additional reference as desired. A L T H O U G H T H E N ational Safety Council endeavors to eli minate from discussion at its conventions matters which are not pertinent to its purposes or which are contrary to its policies, the Council cannot accept responsibility for the view s expressed either in the papers presented or the discussions thereon. 2 I CONT Council Officers and Directors................. Council Purposes and Policies............... . Annual Meeting of Members.................... P,anquet and Dance.............................. Subject Sessions-- Accident Records................................ Dermatitis ........................................... Dust Problem in Industry................. Falls of Persons.................................. F ire P rev en tio n ...................................... Handling Materials.............................. Hoisting Chains.................................. Maintaining Interest in Safety........ Practical Medical Program for Ind Industrial Nursing............................ S afety E q u ip m en t.................................. Safety Organization and Program.. *>Safe Use of Chemicals in Industry. Safe Use of Electricity in Industry. The Eye and Its Relation to Safety. Mental Training for Safety..................... Accident Prevention Equipment Manufa l Aeronautical Section................................ A. S. S. E.--Engineering Section...........' Automotive and Machine Shop Section. Cement Section.......................................... Chemical Section........................................ Construction Section................................ Delivery, Taxicab and Bus Section........ Electric Railway Section......................... Food Section.............................................. Marine S e c tio n ................................................. Meat Packing, Tanning and Leather In Metals Section............................................ Mining Section........................................... Paper and Pulp Section........................... * Petroleum Section.................................... Power Press Section............................. Public Utilities Section............................ .Quarry Section............................................ Refrigeration Section.......................... . . . Rubber S ection ..................................... . Safety Section, ARA--Steam Railroad S Textile Section............................................ Woodworking and Lumber Manufacturi Index ............................................................ National Safety Council Incorporated 20 North Wacker Drive, Chicago Honorary Members ASSOCIATION. OI 11:ON ANll StKEL FULIRKAI. E ouert W. C amer ku . A rthur W illiams Kni;|\'K.HIS OFFICERS (1933-1934) J o h n K. Lose.. President. Kmiifht I. O ri.i.v , Vice-President for Public Safely. .1. E. C i 'U . inf.y . Vice-President for Engineering. G. T. Hn.i.MCTii. Vice-President for Finance. Lew ){. P a l m e r . Vice-President for Safely Councils. K. T . S oi.e x s t e x . V ice-P resident for Membership. ( \ W. S m ith. Vice-President for Business Adminislration. Gvnm.r. 11. W.surF.i., Vice President for Industrial Safety." D r. C. H. W atson, Vice President for Health. A. W. W iiitnkv, Vice-President for Education. W. I-'.. W orth, Treasurer. W. H. C a m e r o n , Managing Director and Secretary. EXECUTIVE COMMITTEE (1933-1934) C. P. A v ti., Past President. I. L P a n a s h . Past President. C. W. llF.Kr.rjrisT, Past President. E arl E. P l a n k , Metals Section. W. II. C ameron, National Safety Council. Eoin'.iiT W . C amerf.i.l . Past President. Until ur I. I'.mt.i n . Aetna Life Insurance Company. J. E. C im.lin f.v . Pethlehem Steel Company. (Juitoru D a v is . Memphis Safety' Council. I.favis A. ltr.P.i.ols, Past President. M arcus A. Plow, Past President. J) D. F en m i.i . Chim e Safely ( oimril. Donald A. Pi nki:i.i nit;. Toleiln Safely I'nnncil. IIowauh Pi. 1'oNiiA, Burroughs Wellcmne ft I n. (U .S .A .) Ine. O h i o M. C r a ve s, Tin? firm-nil Crushed Stone Company. H akrv G iti.iikrt, T he Pullman Company. G. T. 11f.i.lmvth . Chicago, North Shore ft Milwaukee Railroad H arold G. H offman. Street ft Highway Traffic Section. \V. D. J u m p s , James Manufacturing Company Company. 4 / i 1 ^ t ?! -VK>j! : Office, W.-.i' H G. L lN i, ."ast President. Franklin M. K rf.ml, Evanston S (.'. L. I.aFountaixf., Great Northc John JC. J.ono. The Delaware ft L M. J. McCarthy, Automotive ft A H k.nhy M inf-cr, Elizabeth Safety A rthur T. Mokf.v, Past President P. W Ni;rr. Accident Prevention L ew R. P alm er, Equitable Life A E. M. P kiter, Public Utilities Sec C. E. P eitiuune. Past President. Ai.iikkt S. R eoula. Industrial Rela I t. Cm. H enry A. R eninoer. 1'a John B i/ ssei.e. J r., Newark Safety t'tiAS. E. k i r n , Delivery. Taxicab Giouoe E. S anford, General Elcctr Haiiiiy A. Sitiit.tz, United Slates C harles P. S cott, Past President. Lester D. S eymour, American Air F. L. S imo.nus. N ew H aven Safety l '. W. S.MJ n ff Standard Oil G>mp; K. T. Soj.enLi kn, Elliott Servit e C A rtiii'h M ./ Toiie. Consulting Mari C. P. T ulman. Past President. Gitm-cf. II. W arff.l, Union Pacific Dr. C. II. W atson, .'.inoncan Tele S. K. W iirrixi;. A SSF-Enginccring A. W . W hitney, National Bureau W. E. W orth. Internationa! Harvc A riiiit! 11. Y oi-.no, Past President DIREC" W i i i .iam F. A rmern, Safety Divisit P, M, A r t h u r . Mining Section. J. I. P vnasii. Consulting Engineer, L. A. P aknjtz, York Safety Comic Ernest W . B eck, U nited Slates 11 II. W. P kkkman, Berkeley Traffic W. A. Bennett. W orcester Safety I . G. Bentley, lsn-lnm>ml Safety C C . W . Bt Rc.Qiusv, W estern Electric ItAcm S. B eyer, Liberty Mutual In K. W. B lack, Petroleum Section. E mu. F. B l a n k . Jones ft Lmtghlpi W arren S, B i.anvf.lt, Troy Safety N athan P, B loom. Louisville Safet C. F. Pollkenhauen, Kenosha Safe Cm.. I"mi. 1 L -B ro ck m a n , St. Loni 6 '1'ocnly-sccoiid Coiii/ress--National Safely Council R. A. B ryant, Safety Division, Syracuse Chamber or Commerce. . W. H. Cameron, National Safely Council. Knn.Rr I. Catlin, Aetna I-ift: Insurance Company, i rank II. Cogan, Marine Section. U h i. Cooper. Marshal! Field & Coni|iany. W . F zei.l Craig, Safely Dcparlrneiit, Nashville C"liamlier of Commerce. J. F. Culli.xey, Bethlehem Steel Company, him .ncn D an a . Boston Elevated Railw ay. I1. A. 11 widson, Consulting Engineer. Cmitoru Davis, Memphis Safety Council. Richaud H. D avis, Blackstone Valley Safety Connril. 1.. W. D awley. Refrigeration Section. CtiAHi.ES D. D aw sov. Grand Rapids Safety ("oitneil. 1.1. wis A. D eB i.ois. Consulting Engineer. J ay F. D i c k e r , Mason City Safely Council. J ames U. Douglas, The Philadelphia (ins Works Company. D r. Louis I. D ublin, Metropolitan Life Insurance Company. C iiahi-ks H. F ames, Textile Section. H arry \Y. E n i n s , Meat Packing, Tanning & Leather Industries Section. I). D. F ennell, Chicago Safety Council. Ray A. F ixcii, Electric Railway Section. Dox.m.d A. F inkbeiner, Toledo Safety Council. T homas F itzgerald, Western Pennsylvania Safety Council. Howard B. F onda, Burroughs Wellcome & Co. f U .S .A .) Inc. R. B F outuin, T.chinh Valiev Safety Council. 11. G. G ilso n . Paper & Pulp Section. k Du. T homas W . G osling, Child Education Section. Otiio M. Graves, The General Crushed Stone Company. H arry Gun.inner. The Pullman Company. Isaiah H ale. T he Atchison, Topeka & Santa Fe Railway Company. D. T. H arrington', United States Bureau of Mines. G. T. IIellmuth, Chicago, North Shore fv Milwaukee Railroad Company. ( 'has. E. H ill. N e w York Central Lines. IIaroid G. JIo it m a n , Street & Highway Traffic. Section. Ci.aiuie I. H olding, Albany Safely Council. J u l i u s W. TIorre, Hudson County Safety ( otiucil. I Iahrv 1). Imm ei., Pennsylvania Department of Labor &. Industry. W. D. J ames, James Manufacturing Company. A. L. Kaems, Power Press Section. K. T. Keller, Detroit Industrial Safety Council. tra V K ii- . kr, Pennsylvania Salt Manufacturing Company. Louis W . K lruerg, Woodworking & Lumber Manufacturing Section. F r a n k l i n M. K r e m l . Evanston Safety Council. C. L. LaI'oi;ntaine, Great Northern Railway Company. Leonard C. L amb, Knoxville Safety Council, h rank J. L anaitan, Fort Pitt Malleable Iron Company. M, G. L ick teig , Fastbay Safety Council, R alph \Y. Linnt-E, Employees' Publication Section. D r. R. Little N ew York Department of Education. Office .. A. I.CHIMA':. Madison Cou.ily i John F. Long, The Delaware & H. W. Low, Rubber Section. W. R. Lloyd, Safety Division. B H. T. M autin, Fisk Ruhhcr Com F. W. M atrox, Minnesota Safely Paxton M endelssohn, Detroit. H enry Minki.% Elizabeth Safety W. S. Moeli.ering, Ft. Wayne Sa R. B. Mokley, Industrial Accident M. J. McCarthy, Automotive & Miller McClixtock, Harvard Ui T. II. McKennev, Illinois Steel C 1!. W. Nurr. Accident Prevention John A. O artei.. Carnegie Steel ( George C. A. Opp, Detroit Fdisoi Lew R. I'.m. mer. F(|uilablc Life A John C. P arker, Brooklyn Safet; E. M. P epper, Public Utilities Sc C. E. P etthione, American Muti: J. B. P o w i j , Seattle. Traffic & Sa A lbert S. Lnegula, Industrial Rei I/r. Col. H enry A. R eninger, Lc Mauinus Riter, Paterson Safety John Roach, Chemical Section. Charles II. Roloson. J r., Ballimi T hujas Roth. Rochester Safety C< John R ussell, J r., Newark Safet; C iias. II. R im i . Delivery, 'fasica (j. E. S anmiud. General Electric ( H enry G. Sciiaitxek, Erie Safet} T. A. S uhendel. Food Section. Orni Schenk, Wheeling Safety C H arry A. S chultz. United States t iiaki.es B. S cott, Bureau of Saf Ir Min I). S eymour. American A F ari. S. S uautzkk, Utica Safety Gen. John II. S iikkhuhxe, Massa Dr. L. A. Siiounv, Bethlehem Ste E. L. S imoxds, Southern New F 11 George P. S inger. Reading-Berks I. e.e F. S kk.el, Cleveland Safety G C. W . S mith, Standard Oil Comp W. D. S mith. Delaware Safety C R. T. S olexstf.n , Elliott Service ( W. D. S peight. Peoria Safety Coi l. C. S pring, Lansdnlc, Pa. George R. Stepiif.n s, The Safety Luciu s S. Storks, United Ruihv.v A lfred II. S wavnk. General Motors Corporation. A rthur M. T our, Consulting Marine Engineer. W. W . T rench. Schenectady Safety Cmincil. W . D. TritnF.vtLLK, Sail Antonio Safety Council. W illiam I \ V f.k.ch, Rahway Safety Council. V incent W akefield. Kansas City Safety Council. George H. W arffi., Union Pacific Railroad Company, Or. C. H. W atson, American Telephone & Telegraph Company. H arry M. W f.uuf.r, Illinois Hell Telephone Company. S. E. W hiting, Liberty Mutual Insurance Company. A. W . WuiTNF.v. National Bureau of Casually & Surety Underwriters. W . H. W in a ns. Union Carbide & Carbon Corporation. D r. C.-E. A. W inslow, Yale Medical School. H arry W is e , S r., Chattanooga Safety Council. J. M. W oltz, Youngstown Sheet it Tube Company. W. E. W orth. International Harvester Company. E. J. Z ai.t t , Safety Piiireau, Duluth Chamber of Commerce. J. B. Zook, Cement Section. '.'Cl/ i:ct clothes, etc., Tv in air. uld he sterilized, 'from the hands iic skin and open ip plenty of such muing hot water Is for cleansing I'cfore mentioned. -nal diseases and important occupampossihlc because ntinuous contact complete listing "inplctc chemical w processes. stances that are a non-irritating known irritating. : of time of exrk. - surfaces. Make free as possible .lie worker with -lily cleaned and lirt, and keep it and laundered .g Mill Company nailable in comk loads. .ich worker has . d equipment but thing into work leaner who docs mpany time; you .ill find that the in efficiency will T I I ' l i X T V - .S' /; C O X I I . I X X C A L S A / l i T V C 0 X C R l i S S X A r i o X A L S A /' l i T V C O U X C l I. Dust Problem in Industry __________________ FRIDAY MORNING SESSION . *> . . ./ / October 6, 1933 The special session devoted to a discussion of the dust problem in industry was called to order by J. R. Allan, assistant manager. Industrial Engineering and Con struction Department, International Harvester Company, Chicago, who presided. He briefly outlined the purposes of the session'and then presented the first speaker. The Mechanical Control of Dust I B y E. O. JONES Consultant, National Founders Association, Chicago The speaker said in part: During the last lew years, much lias been written about the pathological effects of dust. From this material there seems to be some lack of agreement among scientists as to tiic pathological effects of tiicsc types of dust, their dangerous dimensions, the length of time one must lie exposed to their inhala tion, the density of concentration which is dangerous, and the extent to which they arc directly causative or contributory to disease. / It is unfortunate that in the twilight zone between ethics and non-ethics, there | are certain members of the legal and medical profession who are willing to take advantage of these uncertainties and capitalize on them largely for their own benefit. M heu the foundry ittuustry was cc.u; routed with tlie ru;cuSao'it dial it ..r1jurto! a potential health hazard, its leaders immediately took steps to study the problem, witli the object of eliciting all tlsc facts and determining upon a course of procedure to eliminate the causation. This study lias been under way in some localities lor some time, hut its procedure presents many difficult problems. The mechanical control of dust is not our only problem, nor does the accomplish ment of such control depend upon large expenditures of money. Wc know from experience that gradually human ingenuity will provide ways and means to this part of the problem. Rut let us digress from the subject to consider the amount of dust we as indi viduals create. Take the moldcr. for instance, who goes to his bench at the start of his day's work, li e reaches lor his air hose, and starts the day by removing, with its force everything he can from his equipment. In close proximity to his bench, i oS Tw'iily-.uroiiii Conijri's.s-- Xiilioiiiil Sufcly Council " the window sill in irnnt nf liini, you will usually find a varied collection of relic?. He will usually wet down his sand pile, hut seldom his door or gangway. When he is through with his shift lie usually .crabs the air hose and proceeds to take a compressed air hath. , And we have the foundry laborer: lie has many menial tasks to perform. 'When he sweeps or uses a shovel he seems to be of the opinion that his efforts are judged hy :'ne atmosphere he creates. If he does sprinkle the door it is usually done very 1 sparingly. i pkake-i ut men and crane men seemingly give little attention to the results of their thoughtlessness. Grab buckets are usually lifted to the limit of their lift and then I iumped. Many companies have furnished equipment, such as positive pressure i helmets anil respirators, to employees who work in extremely dusty atmospheres. , -- \ Hut it is surprising to note the apparent lack of interest on the part of the employee t for whose protection this cipiipmcnt is furnished. From tiicse remarks some may say "Why shift the rcsponsihilin f" Xot a bit. 11 We have merely cited these few facts as an indication that possibly \vc can improve P the supervision. If we make every man responsible for the cleanliness in the vicinity . 11 in which he works, and every foreman responsible for his department, and then in r' turn make the superintendent answer for the cleanliness of his shop, we will not ^ rave to worry about the increase in labor cost. After dust gets into the atmosphere. it is. of c u r se , very difficult and expgMsivc to remove. Keeping the foundry floor 11 off the ceiling is a man-size job. Ve:itiia:i"n Is a problem everywhere. A diligent survey of our existing equipment t may devekp the tact that by small expenditures we ran improve conditions. Inspect your dust-arresting equipment. See that the rapping device is in order, that the screen? arc in good condition, we suggest that they are rapped and the hoppers emptied regularly. Repair any leaks in pipes. Sec that the valves close properly. Chutes sin mid he kept in good repair and when emptying arresters, respirators should D be worn hy the men whose duty it is to perform this work. If refuse from the arrestors is not removed at once, keep it in containers or wet down until it is re moved. .Move all. watch your air velocities and make sure you arc removing at * (j; the source as much of the dust as the equipment was originally designed to do. You pay the current the motor consumes to operate your suction equipment, therefore get the proper return for that expenditure. l'lo nr.; store or allow sand to accumulate around your, blasting equipment. Make jj, sure you are receiving the proper air changes in your sandblast rooms. Inspect your ^ masks f the amount of air purging through. The wearer is prone many iimes to t ., just crack or partially open the valve, and when this is done lie is not getting the pj, full protection for which the helmet was designed. Wc suggest that the helmet he pj, removed from the sandblast room and stored at the end of the day in a dust-tight f cabinet, instructing the wearer to clean before re-using. tj,. In your cleaning rooms where tumbling barrels are used, we ileal again with air velocities. Piping should he diligently inspected anil kept in good repair. Make sure traps are performing the service they were designed for. It might he well to keep Hours in this department wet down. Remove the day's accumulation of refuse at the end of the day's run. When cyclones are used, make sure you are not exhausting an. at the level of windows which may he opened in other parts of your plant. Af W e wili have to look to/fu rth er co-operation from the foundry equipment maim- pi" fnc'.urer? who serve our industry. Equipment will have to he sold to us net to eai  OUlicil varied collection of ;s floor or gangway. Ilose and proceeds to to perform. When !u's clTorts arc judged ;> usually done very the result.-, of their ' their lift and then as positive pressure dusty atmospheres, part of the employee oility?" Xut a hit. :!>ly we can improve diness in the vicinity rtment, and then in - shop, we will not mto the atmos]ihcre, .. the foundry floor ' existing equipment I conditions. Inspect i in order, that the I and the hoppers Ives close properly. respirators should If refuse from thy own until it is rc- ; are removing at 1 signed tn du. You { u.iipmeiit, therefore ! ! equipment Make nns. Inspect vonr ; ne many times to t, is not getting the I hat the helmet be I lay in a dust-tight .j ,al again with air repair. Make sure ' t he well to keep ition of refuse at arc not exhausting >r plant. v equipment maim- | ^Id to us net to ! Ihi.-il J 'i o h lc in hi I m h i s l r y 39 meet existing codes, hut as dust-tight as Imman ingenuity can design them. After the equipment is installed, it will he the purchaser's responsibility to see that it is reeulnrly inspected and maintained to perform the service for which it was originally designed. And we icier again to the employee's responsibility. When he elects to work in a foundry, he should he willing to co-operate and wear the saicty devices which arc provided hv his employer, and it will lie the purchaser's responsibility to see that the equipment is well cared for and properly maintained. Our industry is a basic one and we hope that it will long continue to he essential. For this reason we want to assure those who arc sitting on the side lines that it is our determination and hope that, with the help of those in the medical profession who have given so generously oi their time in scientific study, we can soon determine the actual extent of the hazard. -- In the meantime, while many diverse opinions arc heing brought into agreement, it is imperative that wc give more than passive assent to suggested measures of precaution or improvement. The accomplishment of worth while results depends upon the diligent and active co-operation of everyone concerned and the utilization of all known means of prevention and control. Only through united effort can we hope to accomplish an effective program which will give maximum of advantage to employers and employees alike, and to such an end wc arc confident the foundry industry will continue to dedicate its earnest and conscientious efforts. How to Determine the Dust Content of the Atmosphere in Dusty Industries ' t, ' - By DR. E. G. M E IT E R J -y . Director, Industrial-Hygiene Laboratory, Em ployers Mutual Liability Insurance ~ Co., M ilwaukee, W is. The importance of atmospheric dust as an agent in the causation of respiratory disease has long been known. However, il is only within the last few years that this subject has achieved medical and legal importance in dusty industries. I'.ceause oi the extension of compensation laws to include occupational diseases, and through an everincreasing number of legal suits against industrial concerns by employees claiming disability due to dust inhalation, there is need for a severe attack oil the problem of eliminating or otherwise combating the dust hazard. In order to intelligently control the dustiness of the air, the amount of dust present must he determined. With a given dust, two inctors are usually considered; f l ) the number of dust particles in a given quantity of air, which is usually expressed in millions of particles per cubic foot of air: (21 particle-size, usually expressed iu a size frequency distribution curve, that is the percentage less than stated size is plotted against the size of particles. Instruments Used for Determining Atmospheric D usts Many instrument'; have been devised for determining the dust concentration in air and it may lie well to give a brief historical review of this subject. The South African investigators began using the sugar lube method for the sampling of atmos pheric dust iif I b ll; the same method was used by the U. S. Bureau of Mines as early as 1914. By this method a measured volume of the dust air is. passed through 40 Tsvenly-secontl Congress--National Safely Council a Ini' containing granulated sugar, which filters cm the suspended 'list. At the laboratory, the sugar is dissolved in water and the mnnher of dust particles arc deter mined by counting those in a small volume of the sugar solution tinder a microscope. This method of dust sampling had certain disadvantages, the chief of which was the fact that the purest commercial sugar contained a certain quantity of dust, which introduced considerable errors, especially in those samples containing a low dust concentration. To overcome the limitations of the sugar tube method various other devices were developed, one of which was the Palmer apparatus. Tins apparatus consisted essentially of a pear-shaped glass bulb, the lower end of which terminated in a U-tuhe or trap. Suction was applied to the glass bulb by means m" an electric exhaust fan and the volume of air measured by means- of a Tetot tube. Pust-frce dis tilled water was put into the U-tube. The air drawn through the water in the trap broke it up into a spray within the larger portion of the sampling bulb, which washed out and retained the dust. The dust so obtained was analyzed by the usual methods. T he Palmer apparatus also had certain disadvantages, the chici of which was that its efficiency as a dust catcher was low. Tn the search for a more portable type of in strument. which at the same time would yield rapid results, the South African in vestigators introduced in 1916 a new instrument known as the ICotze konimeter. The konimeter samples dust by impinging a small volume of air against the surface of a vaseline-coated glass plate, the vaseline serving to catch the dust particles. The dust retained on the glass plate was then counted under the microscope at a suitable magni fication. The chief disadvantages of tire konimeter are that in atmospheres containing a high concentration of dust, the spots are too dense to allow counting the individual particles and the method can. therefore, dot he used in such eases, also tunny samples had to he taken to secure a correct average determination in places where the dust concentration was variable. A s a result of the different methods of (lust determination being used by the differ ent governmental bureaus and others, it was soon found that the various bust-sampling methods did not yield absolute results, consequently some confusion arose in inter preting the various dust studies. In order to arrive at some basis of comparison the U . S. Tlurcau of Mines conducted a laboratory study of dust-sampling instruments. The results of this study were published in Public Health I'.ullctin Xo. 144 entitled "Comparative Tests of Instruments ior Determining Atmospheric Dusts." (1925 > During the course of this study two of the investigators. Dr. L. Grecnhurg and G. \V. Smith, devised a new apparatus called the impingcr. In the comparative study the dust collecting efficiency of the impingcr was found to he high, and in addition the method offered several advantages over previous methods. After several modifica tions to meet special requirements, this instrument was adopted by the Federal Public Health Service ami I'.urcatt of Mines as the standard technique for the sampling of dust in air. The instrument has been used in the study of a number of dust trades, and is the commonly accepted method in use today, t Size of D ust Particles Taken into the Lungs It has been observed from a study of silicotic lungs that most oi the dust particles that have penetrated into the air sacs are less than 10 microns in longest dimension (1 micron is l/lDOOth of a millimeter, or l/2500th of an inch). It is generally agreed, therefore, that we need not bother with particles larger than 10 microns in measuring the concentration of a dangerous dust. S o that you may visualize the size of these small particles consider a 2S0 mesh ni nctl nded dust. A t the particles arc deter- tmder a microscope. ; IT of which was the uity of dust, which 'taming a low dust | icthod various other i n s . This apparatus j 'f which terminated J ..leans of an electric 1 tube. Dust-free tlis- i he water in the trap* | bulb, which washed , ' (lie usual methods. which was that its portable type of in- South African in- t v konimeter. The ist the surface of a articles. The dust ir a suitable rnagni- spheres containing ting the individual also many samples ecs where the dust j j used by the differ- :ous dust-sampling ; .-n arose in inter- - of comparison the i ..ling instruments. 1 : No. 144 entitled o- Dusts." (1925) . . Grecnburg and comparative study j and in addition the ' several modifica- the Federal Public r the sampling of cr of dust trades. the dust particles longest dimension ' generally agreed, rons in measuring % r isider a 2S0 mesh j 1 Pus/ Problem in Imluslrv 41 screen in which the screen openings arc 50 microns. In the absence'of a beam of light, an atmosphere containing these tiny particles will appear clear to the naked eye, and therefore is extremely deceptive. Only a powerful microscope can make such particles directly visible. It is necessary, therefore, to make a microscopical examination of the atmosphere to learn how badly polluted it may he. Larger particles such as are visible to the naked eye are essentially harmless in the causation of silicosis, as these arc caught by the membranes provided by nature in the nasal and other respiratory passages and are eventually coughed up or eliminated before any damage is done. When small dust particles are dispersed in air, they are carried about like smoke and settle out very slowlyr- Ifow long such particles will remain suspended in quiet air can he roughly determined from Stokc's law. Assuming a round particle to he one micron in diameter, it can lie calculated hv means of this law that such a particle will fall only 20.3 feet in 24 hours. It can he seen, therefore, that any fine (lust dis persed into the air is not only a momentary hazard but remains in the air for an indefinite period. This faet is often overlooked by workmen, ns it is usually assumed that as soon as the dust cloud is no longer visible all dust has settled out. The term "dusty working place" is only a relative one. Most air. both inside and outside of factories, contains some dust. It is, therefore, necessary to adopt a standard content for the dividing line between slightly dusty and dusty working places. The Wisconsin dust rode prescribes a "tentative figure of 15 m illio n countable dust par ticles under 10 microns in longest dimension with tree siiiea content of 35 pc- cent in a cubic loot of air as determined by Public Health Service technique. Variations in free silica content will make proportional inverse changes in this standard.'' Tn ac cordance with this standard Hie permissible count for practically pure silica would he 5.250.000 particles. H ow D ust Samples are Collected As mentioned previously, the instrument used in collecting the dust samples is that known as the "fippinger." With this instrument the air to be sampled is drawn through a glass tube and impinged at a high velocity on a glass plate which is im mersed beneath a suitable liquid contained in the collecting flask. The impingcr. therefore, combines tbc principle oi collecting dust by impingement with a water-washing or bubbling method and so possesses the advantages of both principles. The dust is thus trapped and remains in the collecting liquid. Suction is applied to the impingcr by means o f-a steam ejector operated by compressed air. Where compressed air is not available, a small electrically-operated vacuum pump may he used. Tbc rate of air flow is measured cither by means ni a small vacuum gage or an orifice-type tlow meter. The entire apparatus is calibrated before use against a standard gas meter, so that a known volume <>i air may be sampled. The rate of sampling is approximately one cubic foot of air per minute. The dust-collecting device is placed in close proximity to the breathing level of the workmen involved while performing their respective duties, so that air samples representing actual working conditions may he obtained. After a MilTincut volume of dust-laden air has been sampled, the collecting liquid is placed in a suitable container and removed to the laboratory for the necessary analysis. When the dust sample reaches the laboratory, the entire sample is filtered into a clean graduated flask through a 2R0-inesh screen so that only particles smaller than 50 microns arc permitted to pass; particles larger than 50 microns arc not considered injurious and are, thcrcfurc. removed from the sample. After proper dilution, the contents of the graduated llask are thoroughly shaken so that a uniform suspension is obtained, and two portions of about one cubic centimeter arc removed with a pipette to just fill two Scdgwick-Kafter counting cells. The cells arc allowed to stand at least 20 minutes and the dust particles are then counted by means of a microscope. The microscope with-an Abbe condenser is provided with an eyepiece micrometer, a Id-millimeter objective and a 7.X eyepiece. The eyepiece micrometer has a large' si Itinre engraved on it. and this square-:* divided into lilt) sipiares. one of which is fur ther divided into 23 smaller sipiares. The proper tube length of the microscope is determined hv calibration with a stage micrometer, so that a side of the large .square of tiie eyepiece covers l millimeter (1,000 microns'). The large square of the eyepiece micrometer, therefore, encloses the dust in an area of one square millimeter, and since the counting cell is one millimeter deep, all the dust suspended in one cubic millimeter of the sample is under tiie ruled field. All particles visually less than 10 microns iu longest diameter in one quarter of the field arc counted at five points on the cell, namely, near the lour corners and the center. T w o cells of each (lust sample arc counted and the average of 10 counts is obtained. Control counts are subtracted front the average sample counts, giving finally, average net counts of the number of particles which arc then calculated in terms of particles per culiie foot of air sample'll. Having determined the concentration of dust particles less than ID microns in diam eter in a given atmosphere, it^fs also necessary to obtain information regarding the mineral composition of the dust hciorc any evaluation of the health hazard can he made. In general it may he said that the harnituhiess of a quartz containing dust is usually iu direct proportion to its free-silica (SiO:1 content. It is. therefore, neces sary l" distinguish between "free silica", that is the silica that occurs as quartz, and "combined silica'1, or the silica that is combined with other elements in the various silicate minerals. It should he borne in mind, therefore, that the total silica reported in tiie customary chemical analysis is no measure of the amount of free silica. The quartz content of fine dusts is usually determined he a combination of petrographic and chemical methods. Each dust presents individual problems and no individual technique applies to all dusts regardless of their composition. Those interested in thi> problem should consult Reprint No. 1560 of the Public Health Re ports. February 2-1. 10,1.1. entitled "Tbe Quantitative Determination of Quartz (free s i l i c a i n Pu*l>" hv Adolph Knopi, Professor of Physical Geology, Yale University, and I'niwultaut. United States Public Health Service. . ;. r Discussion of Dust Problems '/r/g By DR. LEONARD GREENBURG Yale University, N ew Haven, Conn. T h / speaker said in pari: On the technical side of this problem you have been presented with two excellent papers by Mr. Jones and Dr. Mciter. There is little that I should add from this point of view. Perhaps the most valuable contribution that 1 can make is to present to yon my own personal view of the broader adminis trative aspects of this problem gained as a result of many years of close contact. In order to (In this, let us analytic the problem in its simplest terms. C o itH x il -4 * > proper dilution, the a uniform .suspension | .'.re removed with a j cells are allowed to ' noted by means of a i eyepiece micrometer, 'iTomctcr has a large i . one of which is fur- | - of the microscope is j .e of the large square ! i loses the. dust in an millimeter deep, all r the ruled field. All v quarter of the field rs and the center. Id counts is obtained, iving finally, average in terms of particles 1 10 microns in diam- mation regarding the I ealth hazard can lie 1 I ' containing dust is ' is, therefore, neccs curs as quartz, and uents in the various total silica reported of free silica. v a combination of Mnl problems and no composition Those Public Health Ke- -on of Quartz (free ; -y. Vale University, l>lcm you have been her. There is little -'.tillable contribution the broader adminisu's of close contact, terms. D:i.tl Problem in fminslry 43 We may begin by agreeing 'lltal piilmnnary fibrosis results hum die inhalation nf certain dusts in known coiimilralinn over a sufficient period oi time. This fact has hren demonstrated repeatedly hy means of imhistrial. kJj'.ratory and pathological studies. On this simple fact. 1 take it, there is complete agreement. Such legitimate eases of disabling pulmonary fibrosis arc held in many states to he the responsibility of the employer. Further, a perusal ..f the compensation laws makes it evident that there exists a decided trend in the direction of broadening the compensation acts throughout the Union for we ;iml from time to time that additional states are being added to .the list of those holding silicosis to lie a com pensable disease. W e would certainly he blinding ourselves to the facts were we not to admit the existence of this trend in social legislation. It should lie pointed out lure that this is a very wholesome and desirable state <: affairs. The insurance principle has justified its existence in spreading the burden of ill fortune over a long period of freedom from catastrophe and surely in the case of industrial accidents it has freed us from the deplorable state of affairs in existence prior ti. 1912. In the case of the occupational diseases we may hope for equally satisfactory results. Nevertheless, compensation insurance is not the complete solution of the problem at hand. The only adequate means of avoiding the burden of silicosis is by the preven tion of this disease. All other methods do not touch the crux of the problem and they carry inf their wake a vast amount of litigation, il'me-s. ami a large financial burden on industry. If what we have agreed upon to litis point is true it is obvious that industry must prevcm*tlic dissemination of dust in hm workroom air l>v such adequate engineering techniques as arc available: or in certain eases where ibis s not possible industry must provide, and tone the workar to :;.r, mu-Ii menus of personai protection as will adequately safeguard him again-: the inhalation of dust, it i- only hy these means that we ran guarantee a nature free of istthiing pulmonary disease due to dust inhalation. In spite oi the very best efforts of industry to .s..jvc this problem there will un doubtedly lie a certain number oi eases brought to the e-uirts and presented as legitimate eases of silicosis. While some oi these are true cases oi silicosis others. ! have been informed, arc not, but are designed merely as a means of obtaining funds t'r.iin industry. A consideration of such eases brings us logically to the second part of the present discussion. What is the ideal method ! handling compensation eases with reference to occupational disease ami more particularly silicosis? if e.r examine (he development m the-compensation nets we find that a technique designed primarily to ad.iudiealc cases of industrial accidents has hy degrees been given jurisdiction over occupational diseases. In fact, it; onr.e states diseases are regarded us injuries so that thee may be brought within the scope of the original compensation acts, lint on close examination it becomes apparent that diseases are far more difficult to adjudicate than are the ordinary injuries arising in industry. They present many technical facets and often require a detailed knowledge of this partieular branch of medicine with which the average commissioner is very often unfamiliar. As a result we find ill practice that the Court is presented with highly technical evidence hy experts for the plaintiff and for the defendant which is very difficult if not impossible to satisfactorily evaluate. Often the commissioner is caught between the conflicting views of such witnesses and is not provided with his own experts to aid hint in arriving at the real scientific background of the problem at hand. 44 Tteciity-jcroiid Cont/icss--National Safety Council What we really need is a strengthening of the technical side of tile compensation acts to eep pace with the increased tactual understanding regarding the occupational diseases, This does not merely refer to the Courts themselves Inn should begin with the promulgation ot accurately worded compensation acts which clearly define the diseases for which compensation is to he paid. Compensation commissioners should he assisted hy hoards of technical experts composed ot engineers appointed hy the deans of the various engineering schools and of physicians appointed hy the deans of the recognized medical schools. The engineers selected should have a very com plete knowledge of factory conditions and the field ot ventilation, and the physicians should ho experts in the field of industrial hygiene and occupational disease, ft is only with the aid of such highly specialized hoards, or their equivalents, that the compensation commissioners may he aide to do complete justice to both sides in these highly technical cases. It is the belief of the speaker that employers and em ployees alike would benefit greatly from the establishment and use of such hoards. In order to hasten the establishment of this system employers are justified in ap pealing to their legislatures with this end in view; certainly such a legitimate demand should receive the hearty support of all concerned. Frequently one is asked, what should he done with those claims which arc based on little or no real evidence of injury to the worker hut which arc merely reared by some very enterprising attorney? Such claims are, l have been told, becoming very common of late and constitute a real problem to industry. It is obvious that the compensation advisory boards sueecslcd rarlier will, as soon as they are formed, serve the future as a healthy bulwark against this type oi baseless claim and I venture to predict that few such cases would he favorably acted upon hy a.board of real experts in this field. At the present time factory oiiieiais should employ the very best legal talent available and should reinforce such legal talent with technical and medical experts thoroughly versed in the field oi silicosis. Many cases have been lost hy a failure to bring to hear the requisite technical aid required to prove the non-existence of a hazard. Here is an excellent example of a case in which money may he saved in the end hy increased expenditures. W e now arrive at the final steps in the control ot this problem, the physical and X-ray examination of the worker, lsverv factory should have pre-empioyment and routine post-examinations. It seems obvious that the burden oi the health of tire worker should not be placed on the plant without the privilege of the pre-employment examination. How can industry he legitimately expected in hire a worker "in tiie blind" to iiis or her physical condition and then a day later he expected to shoulder the burden c.f the worker's health? Hy repeated physical examinations it is possible to discern the faint early deviations from normal health if any lake place. In this manner the employer would be forewarned very early it any workmen showed lung changes suggestive of early silicosis. The routine industrial health examination on a brtjfl'd scale throughout the major portion of American industry would constitute a public health procedure of major significance. Ily its means a very large propor tion of the population would be aided in the prevention of the degenerative diseases of middle life which today constitutes such a real menace. 1DJOURSMENT