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/ AIR HYGIENE FOUNDATION OF AMERICA, Inc. FIFTH ANNUAL MEETING^OF MEMBERS i . # . f* PITTSBURGH, PENNSYLVANIA NOVEMBER 12-13, 1940 g;  0) ... I -*' > o co , t, n d *3 ft d s 4* s d rH P* O 3 c s o 3 3 (o0 m 60 .o d o a o *1 ft ft +-H d H rl +3 SO a Hi o ad 4d 0 1 .+d3 f? rH H CdO Xt fk CO trH rH 0} *a a 4a> a o dc> p 9Q 8 3 +> a to S3 p <d *a o a en a s fc d co a o d o >3 d o a xt o 6- 0>> H 1 t-t O O .H H a O o r< 4* *dd o ft a . fc) M 4 s3 ^ 8 ++> -r4 ^ fk r~i O rH > 304 1 / PROCEEDINGS OF FIFTH ANNUAL MEETING OF AIR HYGIENE FOUNDATION OF AMERICA, INC. NOVEMBER 12-13, 19-10 s Oiio r Sj I - --1-|- ! I I in r I* -*- `  t CONTEXTS Introduction-- Roger A. Hitchins ..................... Foundation Activities in 1940-- II. B. Mcller ............................... Report of Membership Committee-- C. E. Ralston ........................................................................................................... Report of Preventive Engineering Committee-- Philip Drinker Foundation Researches at Harvard University-- Significance of Particle Size in Silicosis........................................ Control of Fumes and Gases from Arc Welding with Coated Rods ..... Design of Lateral Exhaust Hoods for Industrial Tanks............. Page 1 3 6 9 10 12 Report of the Medical Committee-- A. J. Lanza, M. D......................................................................... ......................... 17 Foundation Study of Sick Absenteeism in Industry-- Dr. W. M. Gafafer ....................................................................................... 20 Foundation Research at The Saranac Laboratory-- Individual Susceptibility to Toxic Dusts-- Leroy U.Gardner, M. D................................................................. 26 Foundation Research at University of Pennsylvania-- Further Developments of the Observation of the Reaction of Living Tissue to Silica Granules in the Living Mammal-- Eliot R. Clark, M, D. and Darrow E. Haagensen................. 36 Discussion ......................................................................................... 39 Review of Recent Occupational Disease Legislation-- Theodore C. Waters ........................................................................................... ' 42 Activities of U. S. Public Health Service in the Defense Program-- P. A. Neal. M. D................................................................................................ 56 Health of Electric Arc Welders in the National Defense Program-- Gordon C. Harrold, Ph. D; Stuart F. Meek, M. D; and Carey P. McCord. M. D......................................................................................................... 63 Industrial Hygiene and the Navy in National Defense-- Captain Ernest W. Brown (MC) U. S. X.................. .......v.......................... 77 Absorption and Excretion of Volatile Solvents-- Howard W. Haggard. M. D........................................ 85 Health Requirements on Government Contracts, Including Importance of Good Working Standards in National Defense, and Health Requirements under the Walsh-Healey Act-- L. Metcalfe Walling ........................................................................................... 92 Protection of Civilians in War-- W. P. Yant ............................................................................................................ 302 ' < rr? Trr < A y-'i.-r 0ii04 1/V r T.riiW.Y -lit % PROCEEDINGS OF FIFTH ANNUAL MEETING OF AIR HYGIENE FOUNDATION OF AMERICA, INC. NOVEMBER 12-13, 1910 TUESDAY SESSION NOVEMBER 12, 1940 The Tuesday morning session was called to order by Chairman Roger A. Hitchins at 10:00 o'clock. INTRODUCTION ROGER A. HITCHINS* The activities of the Air Hygiene Foundation are particularly important at this time when all of our attentions are devoted to the defense program. It is well to remember that the men behind the machines of industry are as important as the men behind the guns. National preparedness depends upon production, and production depends upon able-bodied, able-minded workmen. Therefore, what can be more vital to the success of the whole defense pro gram than the defense of employees' health? In the first World War it is estimated that eight to ton workers were required in mines and mills keep ing one soldier supplied at the front, and even a greater number is necessary now that war is so thoroughly mechanized--perhaps twice as many. There is also the acknowledged shortage of-highly skilled workmen like tool and die makers. The services of highly skilled employees become all the more vital because of their scarcity, which is all the more reason why their services should not be lost through preventable illness or occupational disease. Another significant phase of this Foundation, too often overlooked, is the fact that it is a voluntary undertaking by American employers for the protection of employee health. You will find nothing like it in the totali tarian countries. The day of voluntary action in those countries is gone. Employers are told what to do and they do it--or else! Voluntary action by employers in dealing with social-economic problems might have helped avert the failure of democracy in those unhappy 'lands: There is no need for high-handed Governmental edicts when employers recognize their responsibility and face such problems themselves and deal with them intelli gently as is being done through this Foundation on the problem of employee health. In my opinion, industry generally recognizes these days its social re sponsibly to employees, and based upon my experience in the affairs of the Foundation, industry U practically unanimous in its approval of the work being done by the Foundation. At the same time when we look at the Chairman, Board of Trustees. 1 01x05 vurr-r rr Si li Foundation's membership and fmd only 225 company names we are incline, to wonder why industry in recognizing its responsibility permits this Four, dation's work to he hampered by a lack of support. Instead of only 20C companies there should be 2,000 participating in tin's work; which leads us to the question of what can be done about it? In our opinion two things can be done: Jet every member of the Foundation take a more active interest in this work and let every member try to secure another member who will support the work of this Foundation. . .* - > ... A' FOUNDATION ACTIVITIES IN 1940 H. B. MELLER, Managing Director Membership and Income The total number of members remained the same as at the close of 1939. During 1940 eleven members resigned {1 each in membership groups 3, 4 and 5; 2 in group 7, and 6 in group S). Meanwhile eleven new members affiliated (1 in group 4, 2 each in groups 5, 7, 8 and 9, and 2 insurance companies). The income from fees and dues in 1939 was S32,999.81; in the first ten months of 1940 it was $32,234.52, a slight increase over the same period in 1939. Digest of Literature Popularity of the monthly digest of literature, which cont?:t approxi mately 1,000 abstracts per year, has been sustained. An index was prepared of all items included in the Digest to the end of 1939. This index will be continued annually. The news letters and short, timely discussions of specific health prob lems have met with approval. Inquiries The number of routine inquiries for information or assistance in spe cific problems is increasing. Many of these inquiries come from non-mem bers, whom the Foundation is glad to help as far as practicable. In some cases this has led to membership. I urge that executives see that members of their technical staffs are aware of this "question-and-answer-service." Surveys Survey sendees also are increasing and are broadening in scope as members become aware of their value. An industrial hygiene survey is to a plant v.hat a physical examination is to an individual. Such a survey discloses the presence or absence of potential hazards to workmen. Followed by indicated remedial measures to make safe working conditions and periodic checkup to see that safe work ing conditions are maintained, it constitutes a permanent, official record, to be available as evidence should occasion arise--and who knows when it will? I should like to ask each of you; If claims for damages due to air-borne dusts, fumes, vapors, mists or gases were filed against you tomorrow, do you have dependable evidence to chow to what concentrations your employees had been exposed? The fact that "it never happened before," or the belief that the plant is free from health hazards, makes poor evidence and is a poor substitute for a factual survey report, supplemented by checkup at proper intervals. If you don't know, find out! A company that does not know its hazards, or does not know positively that its operations are free from health hazards, is like a company that does not know its costs. One large member company, which has had its own department of industrial hygiene, has made its own surveys and applied corrective meas- 3 02x07 T> mwmrna^rI urcs in its numerous plants, now turns over to the Foundation the.respy^. sibility for periodic checkins, determination of any additional hazards tl. may arise and recommendations for correction. Another company can* upon the survey services several times a year so as to "play safe" and huvt a continuous record. Several other members are considering similar action; in case a companv has made no survey of its own, the Foundation will start with a comp'tij.. study of existing conditions as regards occupational disease hazards. The Foundation welcomes such action on the part of its member?, believes it can be of Teal service to them, and will add to its staff of field and laboratory men and consultants as may be necessary. Research l Research under the auspices of the Foundation continued at The Saranac Laboratory, Harvard University, and the University of Pennsylvania. The 1 study of sick absenteeism progressed. All of these will be reported upon later in the program. Funds were not sufficient to begin the study of existing exhaust sys tems in industry, which was authorized last year. This will be gotten under way at the beginning of the new year, and it is hoped it can be done without seriously curtailing any other research work, which has brought such val uable results. Cooperation in Defense Program Through a special committee, consisting of Dr. A. J. Lanza (chairman), Mr. V. P. Ahearn, Dr. A. G. Cranch and Prof. Philip Drinker, the services of the Foundation were offered to the Government in the National Defense Program. Dr. Lanza will report upon the activities of this committee. Various of the medical and preventive engineering committee members are actively cooperating on National Defense work. For example, Dr. Selby is chairman of the Industrial Medical Committee of the National Defense Council and among the members are Dr. Lanza, Professor Drinker and Mr. Yant. A series of brief bulletins has been inaugurated on Industrial Health Defense. These are not intended so much to inform as to remind, lest important health items be overlooked in the break-neck rush of increasing production. They are simple one- or two-page summaries touching a few high points and presented as popularly as possible. Some are in a form that can conveniently be placed on plant bulletin boards; a number of companies ; did just that with the one-page circular on the common cold. Public Interest The amount of attention which the Foundation's work is accorded in the journals and the daily press is gratifying evidence of the soundness of our policies and the general public interest in our work. I For this reason, and because of the close cooperation which the Founda p tion enjoys with federal and state agencies, as well as its friendly relations with labor, an increasing amount of goodwill is attached to Foundation membership. (j It has been suggested that we issue membership certificates which mem ber companies may exhibit, if they desire, in their offices or on their bulletin 4 0 AUo I till .'nfl T/rr'**"" ' / 'i Ji, Vf * boards. Accordingly, we have drawn up such a certificate. These will be issued at the first of the year to member companies, and as many duplicates as may be desired will le supplied on request. Not a "Silicosis Institute*' A handicap suffered by the Foundation in its earlier years, but which could not be avoided at the time, was the quite generally held opinion that it was in effect a "silicosis institute." It is believed that this erroneous idea has been changed and that now it is fairly well understood that the Founda tion's work extends over the entire field of employee health. The content of the Foundation's bulletins and monthly Digest proves that point. DR. MELLER: We will have next the report of the Membership Com mittee, by its chairman. Mr. Ralston. . y 5 0ii09 -T& It '>* 'W J"*T fr~n i REPOUT OF MEMBERSHIP COMMITTEE C. E. RALSTON,* Chairman Eleven new members affiliated with Air Hygiene Foundation during ths past year. The new members are: Allegheny Pittsburgh Coal Company American Mutual Liability Insurance Calco Chemical Company Colorado Mining Association Industrial Tape Coi'poration Liberty Mutual Insurance Company Maryland Self-Insurers' Association Powers X-ray Products, Inc. Pullman Company Rustless Iron and Steel Corporation Toledo Scale Company Company Meanwhile, eleven companies failed to renew their membership in January. With the business upturn--increased production creating increased need for health protection--a number of these companies are expected to return to the fold. While the resignations balanced the additions, maintaining the total membership at 225 companies, there was an increase of about 400 a year in income. This is accounted for by the fact that most of the companies that resigned were small firms. Six of them were in the $50 a year class, whereas most of the new members are larger companies in the higher dues bracket. As Dr. Meller has announced, there has been a pronounced increase in the Foundation's survey service to its members during the year. This is a significant development. It links the benefits of Foundation membership more firmly with every-day plant operations. An industrial concern which does not know its health hazards, or its lack of them, and have this informa tion in a scientific, specific form, is like a company that does not know its costs. Industrial hygiene surveys are simply inventories. Like inventories, they must be made periodically. The advantages of such a procedure are manifold. In case of claims, you have a record showing what the health conditions actually were at the time of alleged injury. That is, you h.ave this informa tion if you have been making periodic checks over a period of time. The report you receive from the Foundation removes the "guess work" and speculation as to whether there was or wasn't a hazard at the time in ques tion. Further, as Mr. Fletcher pointed out here a year ago, a survey report from an outside, independent agency carries more weight in Court or before a compensation commission than does a report prepared by your own people. In other words, an outside party can talk with greater weight about you than you can talk about yourself. You all know man's capacity for spreading rumor, how tales grow when Safety Director, Pittsburgh Plate Class Company. C 0 Ll X 1 0 , jut'.' 'll-^ t Bn i :1 , I : 4 i :;4 P4 "-a repeated and how sensational they can become. Sill, working in one corner of your plant, says, "there's a lot of dust here." Joe say:-., "maybe it's ?,i!ioa dust.*1 Tom says, "maybe we'll got silicosis." Art cv.jb'..1., and says, "may be I've got silicosis." Bill excitedly suggests, "r.'.&y.ve we've all got .=;)<cosist" And so on and on. Tins sort of thing stir- alarm, unrest ar.d may stimulate claims. In order to assure their workmen that they r.eed r.ot fear for t'r.'-.ir health, some member companies not only have the F'.-wiation make peri v,.'c surveys, but they post a summary of the findings or. plant bulletin board*., in all the Plants of the Pittsburgh Plate Glass Company, we have endeav/r*:'! to explain in detail to the employees the conditions prevailing around thorn. When surveys were being made we explained the purpose, as well a.-; tr.e results, and in all instances the response from employees was vory pleasing. The survey service is developing to the point where the Foundation being asked by some companies to take over ali of their survey * .. h. relieves them of thy responsibility. After the completion of a broad hea.t-o survey of all of our operations, an Industrial Kyjri%.*i'-t was added V. my staff. We continued this arrangement for five years and during that per.od placed all the operations on a high plane from a health standpoint. At v.e present time we find that only an occasional check 1* required--aside frvm special surveys in connection with new installations. Our present program calls for using the facilities of the Air Hygiene Foct-iari-.r. for survey wvta in addition to our Medical Advisor, Dr. C. P. McCord, " ho made our oriiri* % health survey. Some companies have joined the Foundation :*..* the purpose of havlrg a small survey made and, gratified with the results, arpar.ded the work vo cover a whole plant or group of plants. But surveys are just one reason for Four.dar.;r. membership. Th:>. A the only national association of private industry that I >r.c*w that is sur>pc-r>* Ing broad research on industrial health. At this m.n-.rir.g you will h*%r progress reports on the findings from this resc-ar;*. research or. In dustrial health may not excite you, it may be hart u: .wl but rems.v..'.*%v this; research is the only path to progress in industrial health. Obvicu someone`must do it. Now is it to be done by ir.cusury. vie-** problem or are we to join the ranks of those whose solution f:r every problem. _ "let the Government do it"? That philosophy i= clva e.-s.ry way out bun .o leads to tragic results. When we get to the point wb*re Government la doing everything for us, then we have some form, of state socialism. 71v..t country has become great on the philosophy that gt-^.-r-ner.t exists for *->.<* people, not the people for government. One of the brilliant features of Air Hygiene Ftu-'tuarkc: :? this: It is a voluntary undertaking by industry to cr-.v-vt industrial heak-r.. And where industry attacks a great social-eccr.cm.i? r.mtlem vclur.tar.lv there is no necessity for Government to step a.tri rwrulai*. Ir. cv.em words, are we to do these things for ourselves tr i-e we to sit back v*t have someone else do them for us ? There is nc-th:.* t :'.i '-latched about v.- * Witness the fact that democratic Britain has recently. r T-v"?rr.rr.er.t decw told English industry that it must meet certain rvru-.rvrwrcs in ircu.'T.-M. health, and that it must retain the counsel of ccm-.*rz**r.u:$`.z :r. v..field. But there are more patriotic motives for Four*;j.u':r membership. 7 f r *> i y.. .T-rifc a g>*rv >g .ne health of workers is as important as the health of soldiers in girding Ar.<ica. Deien.se production demands the defense of employee health, for . is a war of workers and machines. Hence, the health of workers is important now. Air Hygiene Foundation can be of vital assistance to industrial concern in helping safeguard the health of its workmen. DR. MELEER: Next will come the report of the Preventive Engineer;'-. Committee, which will be presented by Professor Philip Drinker. *" f A tv $ E I -V t-- REPORT OF THE PREVENTIVE ENGINEERING COMMITTEE PROFESSOR PHILIP DRINKER, Chairman During the past fiscal year of the Foundation, one fellowship has been maintained at the Harvard School of Public Health. The incumbent is Bernard D. Tebbens, who is a candidate for the Doctorate of Science Degree at Harvard. He has worked on two problems, one involving a study of par ticle size in relation to silicosis, and the other comprising a study of the gases and visible fume evolved in arc welding with coated rods. I. For the studies on particle size and silicosis, dust samples of finelyground flint, 99.37c SiO were prepared as follows: 3.3, 1.7, 1.0, and 0.6 microns. As stated in our 1939 Report, the object of Mr. Tebbens' work with sized particles was to study the relationship of size to potency (with respect to silicosis). It was generally admitted that the potency increased as the size decreased but, so i?v as we know, no studies had been made cer tainly none published) which attempted to answer this question with patho logical proof. We are indebted to Dr. R. Z. Schulz, of the Department of Pathology, Harvard Medical School, for his cooperation in this work and wish to make clear that he will be joint author with Tebbens of a paper detailing the complete study. For each size group, nine rabbits were used and each received 400 milligrams of dust in saline suspension injected in two equal doses at threemonth intervals. No animals died from the injections. One animal from each series was sacrificed at about three-month intervals. Histological sections of the liver of animals sacrificed early in the exper iments showed differences in liver damage. After the first three months, animals receiving 0.6 and 1.0 micron dusts showed small though definite evidence of scarring. Microscopically, they had small areas of necrosis and fibrosis distributed particularly in the portal areas of the liver. On the other hand animals injected with 1.7 and 3.S micron dusts showed no gross pathological changes. On microscopic examination, only numerous macro phages and giant cells were found scattered throughout the organ. As the experiment progressed further, gross pathology became increas ingly evident in the animals which had received th two finer sizes, and even to some extent in animals haring 1.7 micron dust. This pathology was par ticularly evident as fine wrinkling of the liver surface, merging into clearlydefined nodulation and white areas of fibrosis. A gradual enlargement of liver and spleen was also noted. In the last group of animals, such striking gross pathology was evident that there is no doubt as to the relative importance of these dust fractions in producing tissue damages. These animals had lived about 17 months since the original injections. The animal receiving 3.3 micron dust had slight enlargement of liver and spleen with negligible other appearance of pathology. Those receiving 1.7 micron dust had very noticeable enlargement of the } organs, and the liver was coarsely nodular with white fibrosed areas. The 1.0 micron animals showed complete fibrosis of about Vs of the liver, the remainder being distinctly nodular. The spleen was enlarged about three or four times normal, but was otherwise not remarkable. 0 ins 1 * *- ; *" *%*'*'% .7 . * T. ' s' f r ir* % 4?VrA,' MM The O.C animal functioned on about U of the liver, which itself va, coarsely nodular. The remainder of liver tissue had been completely <.?, eralcd by fibrosis. The spleen was enlarged several times and showed v.'. miliary tubercules over its surface. Other organs, such as lungs and i, marrow, showed distinct evidence of fibrosis. Kidneys of all animals hi. appeared normal throughout. Engineers are concerned with particle size in the causation of silic.->because we, and not the physicians, are responsible for dust control and : making estimates or counts of dust concentrations. From the resuits Tebbetts and Schulz, it is evident that methods and apparatus designed abate dustiness or to estimate dust concentrations should be directed e.-pcially against the particles well below and not above 1 micron in size. II. A part of Mr. Tebbens' fellowship work has been devoted to a stu-: of the nature and quantity of the fumes and gases liberated during ar welding with coated rods. Not all electric welding today is done with coats-, rods, but their use is increasing rapidly. In the case of alioy steels anci ci non-ferrous metals, coated rods are the rule and the exception. L general. primary purpose of the coating is to shield both the arc and hot metal from reaction with constituents of the air> Time would not permit studying the full list of the coatings used cr. modern welding rods or the products they give off in the arc. With the he/, of welding experts from the General Electric Company, who supplied the equipment needed for this study, we selected a number of representative rods, of which the makers generally furnished the approximate analyses. Ithose few cases where analyses were not available, it was not difficult t: determine the essential ingredients and to check them against the products of combustion in the arc. Every effort has been made not to divulge any trade or manufacturing secrets regarding the exact nature of the coatings. A. Low-Carbon Steel Electrodes: Seven different electrodes were stud ied in three sizes, 5/32", Vi", and 5/16". The coatings contained the following: Ferromanganese, the Mn serving as a deoxidizer. Various silicates, including asbestos, with small amounts of free silica. Sodium silicate as binder. Titanium dioxide as an arc stabilizer. Carbohydrates to furnish a reducing atmosphere. i B. Steel Alloys and Non-Ferrous Alloys: The coatings of these rods all contain fluorides, usually carbonates, and some silicates. The coating cf rods for welding aluminum contained chlorides, while one alloy rod, a 90 Cu 4 Si rod, contained borates. In general, all rods and all coatings gave off a visible fume or smoke of which the qualitative composition was predictable from the analyses of the rods. In addition, we looked for any volatile fluorine compounds, as well ^ as carbon monoxide, chlorine or hydrochloric acid, and especially oxides of nitrogen. | Welding was done in a gas chamber equipped with a special exhauster r and a hood placed near the welding work. Beads were welded across small metal plates and the gases and fumes from the arc were drawn into the hood by the exhauster. Samples of gas and of the visible fume were taken from the flue pipe and analyzed. From a considerable series of such analy ses, it was possible to construct a table: < io j i 01114 ; ..... . Jjnmim ? c: f** If welding wa done at various distances from the hood it was py. to determine at what suction velocity, measured at the arc, all visible and pas entered the hood. H was also possible to predict, with fair ac-ciar. the gas and fume concentration after a definite time when welding uad:.-' particutar condition. It follows, therefore, that one may write specificai;^.for the necessary ventilation to bring about any desired condition. In general, we believe that modern electric welding is a safe job, pr.viding that the worker observes certain simple rules: He must avoid ultraviolet light from the arc and his skin, especialhands, face and neck must be iirotected. We have no fault to find with t.v conventional safety practices with regas-d to these items. He should not weld in confined spaces, like tanks, unless they are we; ventilated, or unless he is supplied with an air mask. If the concentration of visible fumes is kept within reasonable limitby means of appropriate ventilation, there will be no risk of poisoning N02. This does not mean that N0.> gas and visible fumes are given off in a:.-, constant ratio. They are not. But low concentrations of visible fumes, as 20** mgs./cu. m., preclude any possibility cf narm irons breathing gaseous impurities. We had formerly a second fellowship, held by Leslie Silverman, be: this was stopped at my suggestion because Mr. Silverman was appoint*; Instructor in this School and had to devote a large part of his time to teach ing and not to the research in which the Foundation was interested. How ever, his original thesis work, made possible by the Foundation's generosity, will be published. The purpose of Mr. Silverman's work was to study the factors affect:::^ hood design for single-slot unheated tanks, such as those used for cold plating, pickling, acid-dipping, alkali baths, and wash tank?. The effect temperature and of solvent characteristics on ventilation requirements, together with the performance' of double-slot hoods, is being studied further. Ventilation requirements (Q) of unheated tanks with lateral exhausts were found to vary as follows: Unflanged hoods .... Q = 2.3 (width)1-1 (length)055 (velocity)* Flanged hoods........ Qf = 1.9 (width)'*- (length)0-7 (velocity)* The optimum height of flange is that equal to tank width and the opti mum flange inclination is the maximum allowable without interference with itKlustrial operations. Slot velocity or slot width are unsatisfactory criteria of hood perform ance. The important factor is the quantity of air handled. The depth of liquid surface below the slot does not affect greatly the characteristics of hood performance, but may have an important effect on evaporation and entrainment of liquid. I am assured that one fellowship and perhaps two will be continued at Harvard, and I should favor, in this case, departing from perhaps our straight engineering and including something that is a little more biochem ical, particularly a problem on how the human system handles solvent vapors when exposed to a compound such as carbon tetrachloride. That is, if an individual is exposed to a certain concentration, how soon does his blood become saturated at that concentration, and if be leaves, how soon does ho 12 it * in.* iiir 11 inn, M.-i^-yrThiiV, L .- i*\ i . 4 "t t '_' 4 ;. < t I -: i I -'. 1 .., i J - 3 l A * ,4 *-'t> ` '- become desaturated? The fundamental data on such matters now are badly lacking. I am also informed that our Engineering Committee next year will be able to make the survey of exhaust systems which we projected last year and which we were unfortunately prevented from making purely by lack of funds. I am informed that such funds will be available this year, and we shall go foiward with that as projected in our annual report of a year ago. The Foundation has liberally continued its support of the Journal of Industrial Hygiene and 1 think I can say to the mutual advantage of the Journal and of the Foundation. From my standpoint, as editor of the Jour nal, it is a most desirable cooperative effort. We exchange data ail the time and each helps the other materially in the abstract work, thereby considerably reducing the cost of the combined effort. There is one item in which I would bespeak your support it* it should come up. In the general field of industrial solvents, particularly of common organic solvents, new ones are being introduced continually. Every now and then a lawsuit such as this will arise: An individual, unknown to V*'m<elf, has a tubercular lesion. He receives an exposure to some solvent vapor or perhaps an irritant gas as from electric welding. He does not know that ha has tuberculosis at the time, but a month or two or three later he breaks down and is examined by a physician and is found to be in an advanced stage of tuberculosis. Human nature being what it is, he looks about for some one on whom he can pin the blame and he picks on the employer at that time. That is perfectly natural. You have experienced such suits. We may have our opinions about those things, but to prove them is a very difficult matter. I can number in my own experience two or three such occasions. The proof of the thing is highly embarrassing, even if the firm has worked in the utmost good faith and is of the opinion that it has kept working conditions as they should be. The answers to vexing problems like that might well be obtained by research, especially at Saranac Lake, of the type .that Gardner has done so successfully with dusts, namely, the treatment of experimental animals inoculated with tuberculosis virus in accordance with Gardner's technique: treatment of animals with known concentrations of solvent vapors such as we would permit our workmen to have in their ordinary work, and then seeing whether their condition is adversely affected. You may say that legally you cannot draw inferences from animal experimentation. I'd like to say that you can and it is being done with great success in defending unjust claims. It is the one way you are likely to be able to answer the problem with even a shadow of success. I think that the Foundation could very well interest itself in that prob lem. It is one which is most vital to the engineer, because sometimes we are called upon to take responsibility for a ventilation installation which we have put in in the utmost good faith. Later we find that the individual for whom it was designed, perhaps, is a little below par. tubercular, if you wish, and he breaks down and then they say, "Well, the engineers didn't ventilate this job. If they had done it the way they should this fellow should be all right." I don't think it is our fault, but nonetheless they hunt around for blame and they pin it on us, sometimes with a good deal of success. I note in the program that at the conclusion of what I have to say, and we have reached that point, the meeting is open for discussion. If I or col leagues in the audience can answer questions on these matters, we will be glad to do so. 33 17 I. "V ! .1 J yr kf. W r ^ ^ Yi DR. MILES: When you discussed the effect of those fine dust par on the liver, in what way did you say the dust was got into the rai. Injected? PROFESSOR DRINKER: Yes, into the ear vein. That is an old nique that lias been used for many years in the study of toxicity of va: types of dust. Of course you can produce fibrosis from silica in various j of the body. Putting it in in that way it can be done with precision with quantitative accuracy. The reason we didn't dust these animals b; air-breathing route is because the samples of 0.6 micron dust were mens literally by the milligram and not by the gi-am and we didn't have enc dust to permit inhalation experiments. DR. WILKIE: I'd like to ask Mr. Drinker if he did find anything ir lungs. PROFESSOR DRINKER: Not of any consequence. They showed s! evidence, macroscopically, of fibrosis. DR. SELBY: If it is so difficult to make this fine dust does it acV. exist ;r> industry? PROFESSOR DRINKER: Yes. That is a very good question and a practical one. The trouble is that fine and coarse particles are .intima tied together, and what we wanted were the individual sharply defined : tions. In any place like a foundry or mine, all air-floated dust will con plenty of the 0.6 micron dust. We wanted to get it by the milligram gram if we could, and to get it and separate it from the other size extraordinarily difficult. It is very tenacious. They just stick together. DR. MILES: In your conclusion, then, while you actually examined liver you would say that there was an analogous change in the lungs, mean it would cause fibrosis in the lungs were it breathed in. PROFESSOR DRINKER: I am sure it would. DR. MILES: But there would be no liver change? PROFESSOR DRINKER: if you. breathe it in, the most import damage will be in the lungs, whereas if you take it intravenously the impi ant damage is always in the liver. MR. BAILEY: The inference is that the dust particles larger than microns are harmless? PROFESSOR DRINKER: That is certainly what I think--not tot* harmless but, compared to the others, yes, they are harmless. MR. BAILEY: Isn't that something new? PROFESSOR DRINKER: I don't think so. I think all we have dc is put a hunch that everybody had on a slightly more quantitative basis. DR. LEROY V. GARDNER: May I say a word about this? This subject (toxicity of fine particles) that Professor Drinker k reported this morning is one that we have investigated also. You confir the findings that we have already made with the exception that we felt th if you allowed particles up to three microns in diameter to act long enou they would produce definite and progressive changes in the liver. I hs forgotten how long your maximum observation was. PROFESSOR DRINKER*. A year and a half. 0 i i 1 8 r-. .... -: 'O. - - .' * * -r-- ----------- . -,\y DR. GARDNER: We found that in a year's time the particular quartz with which we worked was active. We set three microns as the upper limit of activity. Four microns to six microns were inert. We all agree, 1 think, that the smaller the particle the more active it is and the more rapidly it produces changes in various organs. The liver that Professor Drinker has used as a test organ is one that wc have used also. When you come to apply this knowledge to inhalation, how ever, you have got to consider whether particles under a micron or a half a micron, perhaps, arc going to remain in the lung in sufficient quantities. We tried some years ago an inhalation experiment with some exceedingly fine silica, whose average particle size was said to have been of the order of 20 angstroms. This material was prepared and measured by a method that I am not in a position to discuss just now. The point I want to make is that when we made animals breathe this exceedingly fine silica we didn't get what we expected, that is, almost immediate death, within a few weeks. We found that relatively little of it stayed in the lungs. There was enough there to produce some changes in the phagocytes, the formation of giant cells, and what not, but no fibrosis developed. There was not enough of the very fine silica i?i the lungs to cause any death of tissue. While it is perfeclt.v uac that the finer the quartz particle or the silica particle the more active it is, it seems to me that our application of this finding must also be conditioned by what can be expected to remain in the lung after inhalation. I quite agree with yon that the engineer ought to be prepared to trap the finest dust that is in the atmosphere and that he needn't be much con cerned about anything over three microns, even though the lung may contain some ten micron particles. Those three to ten probably arc pretty inactive. Whether it is going to be 1.5 or 3, I cannot say, but I certainly feel that it is in that range that we are going to define the upper limits of activity. PROFESSOR DRINKER: I think that engineers feel that we trap the fine dust, but I don't think that we feel that we measure it when we go out into a plant. I think if we catch the I's and 3's we will catch the 0.5's too. But certainly, if we make estimates of relative hazards of one job and another, we don't come anywhere near laying the emphasis on the fine mater ial that we ought to. In defense of my having infringed on the field which Dr. Gardner has so well covered, I should like to say that we were guided in our choice by the fact that in the experimental work which he cited, I am distinctly under the impression that he stopped at three microns. He said that the others were more toxic, but his published data, quantitatively, are on the three microns and over. That may seem like splitting hairs to you gentlemen, but it isn't to me. MR. FRAZIER: I should like to ask if you have actually correlated the different rates between the size particles on those particular animals you have experimented with. In other words, by 0.5 on up. PROFESSOR DRINKER: You mean correlated in a mathematical sense? MR. FRAZIER: Yes. PROFESSOR DRINKER: You can't. I don't think we would ever be able to. You can't do much more than got the results and just present them as you see them, either in gross preparations or histological size, and say 15 s. that one is .<( much worse than the other. To make any precise mathemat ical correlation I am afraid is beyond any skill that we have. DR. FRAKY: Does that not imply that the examination and dust count ing should be done on a dark field rather than light field? I understand you can't get much under one micron on bright field. Some dusts which look very well if you look only in the bright field become very bad if you look only in the dark field. PROFESSOR DRINKER: In defense of the pvesent counting technique, which is light field and does pay particular attention to material that is bigger than one micron, the results of such counts, when they show high f dustiness, correlate fairly well with such data as we have on incidence of silicosis and the like. After all, dust counting as it is done today is not to measure how much dust is in the air. It is to estimate what the silicosis risk is, and from tho present way of looking at things the two haven't a whole lot in common. From the standpoint of precision, I agree very warmly with Dr. Frr.ry. From the standpoint of public health, perhaps the present counting technique will do. PR. RUSSELL: Have the pathological effects of amorphous silica dust and diatomaceous earth been determined by experimentation? PROFESSOR DRINKER: IVc haven't tried any. answer that much better than I. Dr. Gardner can DR. GARDNER: We have tested the effect of diatomaceous earth by this method and found that it is capable of producing a progressive fibrosis that looks very much like that caused by quartz. That is the only form of amorphous silica that 1 know of that will produce this reaction. It has been suggested that the reason for the greater activity of this particular form of amorphous silica is due to the tremendous surface exposed to contact with the animals. The diatom shells are pierced by tremendous numbers of exceedingly fine tubes and as these particles are brought into con tact with the tissues the tubes' surface is added to that of the outer surface. All the other amorphous silicas that I know of are incapable of producing a progressive reaction. A few of them cause a little chronic inflammation, l but that tends to subside rather than progress. PROFESSOR DRINKER: A year or so ago, at the last Saranac Silicosis Symposium, Dr. King, from England, took me, among others, pretty severely to task for the unscientific way in which we made dust estimates. His language was diplomatic, but the implication was that we were somewhat stupid ar.d that the British method of thermal precipitation, which caught very easily the fine materials of 0.5 microns, was superior to ours. Dr. King said that their technique deliberately ignored the bigger sizes, say above three, and took the finer ones, whereas the impinger did its best work beginning at about two microns and going on up to ten. He took us to task, and I think with reason, for the unscientific methods we wore using. On the other hand, we can maintain with some justification that with such as we have we can control silicosis and measure the degree of our control fairly satisfactorily. DR. MULLER: The next section of the program is in charge of Dr. Lanza, Chairman of the Medical Committee. 10 REPOUT OK THE MEDICAL COMMITTEE A. J. LANZA, M. D., Chairman During the year we have succeeded in getting our studies on sick absen teeism in industry well under way. Fifteen firms are now cooperating with the Foundation and with the United States Public Health Sendee in putting into effect what will be a comprehensive record which will show the extent and nature of sick absenteeism in industry. The importance of this is self-evident when we consider the enormous economic loss involved. We will hear in detail of this activity from Dr. Gafafcr, who is on our pro gram today. The Foundation has continued to sponsor research activities at the Saranac Laboratory and this very important piece of work will be described to you by Dr. Gardner, who is also on our program. We also have continued to support the extremely interesting studies on the effects of toxic materials on the living tissue carried on at the University of Pennsylvania, which, will be described to you in detail by Mr. Hangensen. As you know, the studies on x-ray which have been carried out a* Uni versity of Pennsylvania have been completed and are available to the mem bers and to the public in bulletin form. For the coming year we propose to carry on our studies in sick absen teeism, in cooperation with the United States Public Health Service and with those member firms who have requested participation in this under taking. We also propose to carry on Dr. Gardner's studies at Saranac and Dr. Clark's and Mr. Haagensen's studies at the University of Pennsylvania. I should like to discuss very briefly recent advances in the status of the industrial health program throughout the country. The American Medical Association, through its Council on Industrial Health, is continuing its various efforts in this field. The Council not only carries on educational and informative activities at its headquarters in Chicago, but has inaugurated a broad campaign"of education through the state and county medical societies all over the country, having in mind par ticularly the needs of small plants wherein, as you know, some eighty per cent of all our industrial wage earners arc employed. The activities of our own Air Hygiene Foundation are well described in the program of today and tomorrow, but I should like to emphasize for your attention that this Foundation is the only national association including in its membership all types of industries which is actively supporting and financing fundamental research in industrial health problems, without which continued progress in the field of industrial health is not possible. A committee composed of Sir. Ahearn, Professor Drinker, Dr. Cranch and myself, representing the Air Hygiene Foundation, recently went to Washington and had an interview with Governor McNutt, who is at the head, as you know, of the Social Security branch of the Government. We went to see Governor McNutt because the Public Health Service, whose interest we were endeavoring to elicit, is now in that division of the Government. One of our objects in talking to Governor McNutt was to try to make the respon sible people in Washington appreciate the importance of industrial health work in industry and to prevent as far as possible industrial physicians, industrial hygiene engineers, industrial safety men, and other technicians 17 being diverted from their activities in industry into some other form ernmcntal service. Furthermore, we also hoped that the industrial physicians, the ir; hygiene engineers, the safety engineers, and others, who carry enormously important work, which is just as essential a part of .. defense as carrying a gun. would receive some credit or some reco; so that they might not feel that they had not been doing their part general defense program. I might say that Governor McNutt gave us a very sympathetic h and I think some advantage may come out of our visit. The National Association of Manufacturers is continuing its acti-.j stimulating and educating its member firms. This association also is j> its emphasis on the needs of small industries. On the official side, we have the Division of Industrial Hygiene United States Public Health Service. I don't have to talk to you afcimportance and far reaching activities of this division, which have beer, ifested by the energy and thoroughness with winch they have been i mental in setting up divisions of industrial l..-feiciie ir. some thirty governments. Every phase of health in industry is covered in the act. of the Public Health Service. The Department of Labor, through the Bureau of Labor Standard the Bureau of Statistics, is continuing its important activities in the f. industrial health, both through field work and educational publications. Now comes a new factor in the field, and I am referring to the C: on National Defense. Industrial health is a major portion of the nc: defense program and is contained under the Health and Medical Com:* of the Council. The Health and Medical Committee includes a sub-corr.:: on industrial health, the importance and scope of whose activities car.:, overestimated. Two members of the Medical Committee of the Air Ky. Foundation are also members of this Industrial Health Committee it Council on National Defense, gnd one of them, Dr. Selby, is the Chairmi the Industrial Medical Committee of the National Defense Council. This committee is tied in with the National Research Council on ir\ hand and with the military services on the other. Liaison officers have detailed to work with the committee by the National Research Cour.-n. by the Surgeons General of the Army, the Navy, and the Public Ih Service. At no time in our history has the health of the industrial w:: whether he may be employed in plants owned by private industry or in r: operated by the various departments of the national government, rec? so much caveful consideration as at the present time. It is safe to say as a result of the national defense program and its coordinated activ industrial health and hygiene will be established on a firm and perms* foundation throughout the United States. In conclusion I wish to make just a few more comments on the h. phase of the national defense program. Physical selection is an integral part of the program, applying to f ian as well as military forces. The present employment examinau" becoming more thorough and thereby move valuable for diagnosis ar.* for therajieutic purposes. The importance of this, from the standpo-'* public health, is inestimable. Many men with minor and even major defects must be utilized i= 18 oi Q p. AJ f - "JMSMXVC- ''i.'i defense industries, both in the general interest and in their own interest. Men must work where work is available, and it is the function of industrial medicine to see to it that those who present special needs or problems secure the help and supervision that will enable them to keep on with their work. It is important that those who are concerned in the administration of private and governmental industries keep well in mind that the function of a physical selection program is not to bar men from work but to determine what kind of work they can best do and to provide adequate medical supervision, while they are at work. It is extremely important that those who are found unfitted for work-- and I am thinking particularly of those who will be found to have tubercu losis and other general organic diseases--receive adequate care, care that will have for one of its objects as far as possible physical rehabilitation. The defense program provides for our national security. As an essential part of that program physical selection and medical supervision must con tribute a positive force for health that will serve to raise the general health standard of the entire industrial population. That is our goal, and we must strive toward it. I DR. LANZA: We will continue our program. The next paper will be by Dr. Gafafer, the Senior Statistician of the United States Public Health Sen-ice, who will speak on the sick absenteeism study. i I ! i ?m, 1S.V4 FOUNDATION STUDY OF SICK ABSENTEEISM IN INDUS! DR. \V. W. GAFAFEli* Since the last meeting of the Medical Committee progress ha.made in connection with the solution of various problems raised by posed study of sick absenteeism among the member companies of x'< Hygiene Foundation. Thus far 15 companies, representing approx-::. 00,000 employees, have indicated their willingness to cooperate in the the disability plans of these companies including prineijmily mute*.; benefit associations, managed either by the employees or the compar.v contracts with life insurance companies. The Manual, "A Proposed Plan for the Recording of Industrial A teeism,*' edition of May, 19-10, prepared by the Division of Industrial Ky. of the National Institute of Health, was distributed among the repv*-tives of various member companies at the meeting of May 27, 1940. I: explained at that time that the plan as presented in the Manual wa? objective which should be aimed at and that for the time being suiTicie-: be supplied by the companies agreeing to cooperate with the Foundatimake possible the analysis of 8 calendar day or longer disabilities by c: and specific for color and sex. In addition it was strongly emphasized the number of employees under observation should be made avails':-;, color and sex, to make possible the calculation of rates. The numb-.-: workers under observation includes those workers, and only those wo.v whose absences would be reported should they at any time be absent i: calendar days or longer. Thus the analyses with respect to age, occupy and department would be reserved for the future, and only disabilities calendar days or longer would be included. The Medical Committee has given thought to the matter of the met: logy of reporting the requisite information on the absences by the cc<; ating companies to the central-office. It was agreed that the clerical v should be reduced to the lowest possible minimum. For this reasc-n : punch card method of reporting as indicated in the Manual was scruti:: and some members of the Committee seemed to favor the substitution simple report form devised to carry the information on a dozen or so ; sences, the filled-in forms to be used by the central office in the punch: r the cards. Moreover, in the meantime practical knowledge of the ap?`. bility of the punch card method of reporting has accumulated. This ex;ience has shown principally that the use of the punch card outside of : central office has necessitated the repunching and rewriting of not a $r.> number of the punch cards submitted for analysis. It is therefore roc' mended in the interests of reducing clerical labor to a minimum and to a-the possible maltreatment of punch cards that in the matter of report::: form be substituted for the punch card. The decision to use a reporting instead of a punch card lends to a number of consequences not eutirA unfavorable. Thus, it will be possible for a company to keep copies c- r reports, cases will be less easily lost, not-ended cases will be more cachecked, the punch card in the central office can be made more flexible ' special studies, and punching will be facilitated. The form referred to has been made. It is in two parts: Form I carinformation on all 8 calendar day or longer absences that terminated du: Senior Statistician. United States Public Health Service. 20 0 Q /. fj - * P P1 m *--~'IW >`?n*ir 1~fr -'-*1 J--TT*--- HTT i. I c i ,<< l i | $t C S 3 f I fl u i ! a particular month, while Form 2 carries the information on those absences which may have begun at any time and were carried over into the following month. Figures 1 and 2 show the front and back, respectively, of Form 1. The front shows the form proper and the back the instructions necessary for.fiHing in the form. It will be observed that the form refers to a partic ular month. There is space to enter the number of workers under observa tion by sex and color, and the various items related to 14 absences. These items include for each absence, the employee's social security number, his color, sex and age, the date of beginning and date of termination of absence, calendar days absent, hosv the absence was terminated, reason for absence, diagnosis and by whom the diagnosis was made. Symbols that are used in the filling in of the form appear on the back of the form as shown in Figure 2. Thus to indicate how the absence terminated R is used to mean "Returned to work," D for "Died," M for "employee received Maximum benefits," 0 for "Other termination," and U for "Unknown." The front and back, respectively, of Form 2 are shown in Figures 3 and 4. This form, which is the second part of the reporting form, is used to report those 8 calendar day or longer absences which were carried u\er into the following month, 'there is sufficient space to carry 23 unendc'd absences and the particular items covered form a part of those shown on Form 1. The symbols to be used in filling in the form appear on the back of the form as shown in Figure 4. The question now arises of the content of the tables which might be sup plied by the central office to the cooperating companies. Three basic rates should be presented, namely, the frequency rate or average number of absences per 1,000 employees, the disability rate or average number of days absent per employee, and the severity rate or average number of days per absence. With regard to the time periods which the tables should cover, it is recommended that tlio frequency rate by cause, and specific for sex and color, be presented every six months with a particular company compared with all cooperating companies. It is recommended further that the 2 rates Involving time cover a whole year and be presented by cause, specific for sex and color, and showing a comparison of a particular company with all reporting companies. With respect to some of the tables it would be neces sary to combine specific causes when the exposed population of employees is too small to yield data of a magnitude sufficient for the calculation of reliable rates. Thus the number of workers reported upon may be so small that meaningful rates will not be yielded for specific causes in which instance it would be necessary to express the rates for broad cause groups only, such as respiratory diseases, digestive diseases and nonrespiratory-nondigestive diseases. This observation is obvious as soon as stated. In conclusion, it should be stated that for present purposes Forms 1 and 2 as described are recommended in the reporting of absences of 8 calen dar days or longer caused by sickness and non-industrial injuries, these forms to replace the punch card which is to remain in the central office. The Forms should be filled in at regular intervals, preferably every month. Since Form 1 makes provision for the number of workers exposed, Forms A and B as described in the Manual may be ignored for the time being. (This report was illustrated by lantern slides.) r V,JI, ,l . 21 TTT 'P 0 25 ; s i -kiv'ci' o c .55 fig go e*s .S g`E *0^1 o S K g Oii BO. a ^v v O c fe. a. O o Z u o .c > tO. o- to X X o 2 <D CtO OO +> to to CO CM: U o 9 >- tt zo zc- <D <U u -f-> o O -- CO o: to .G CD ^ t-> , Reason i Cor . absence H j= Wo Oa ~t 6 3o O fj (0 <U `5o c Q) bt> 3 x: O a(3 H *-> H o >> T3 i-. O O rt Uo G u 3 b3 O a> d o. o t> Si Q. H c 3 B w 3 ci u 3 a. O [& J o w CO Z CO 10 r-( CO H CM C (t > s Q z> O cc Z o ^ 2 . g o e , e fe** C\J to o CO o t- t> CM H O r. to P bO c C? *o o O O o o c v T \ z _ a ** i1 i1 CD lO CM .r-n to tf 5 D o 3 w R O .S Da c CV 1 H i CM 1 H fW 11 Q C3 , B W *3 5 o o O o o r-t H H r-i 1--1 o *$ < _ID-* Crt 2 s <7) o o O o S S < S to -c *r c V zN 1Ji11 o to CM to to Jx. ci X O Qf; *> aU CM u XI r I 1 1 1 K <3 o CO o o o > c 11 H HHH (0 ft e. to K 1 eo to CD CM to o O5 o Z o r-t < CM to to 63 2e<a? mX4> 2 2 B. S *c cL == S O z & <3 0 u c C zG .o s Z Employee's Social Security Number O to to e' <y> t- to t- en N co CD CT) CO CD CD CO CO CD I11 11 to to to to LO M* ^r M1 V V 1\1 \\ to to to to to CM CM CM CM CM r--( r~| rH mi rH 22 01 i 2 C v'. _ . , II -- I I i "I'l 'mnast^i .- hj^iwii hi '".!~ g',~'JT. -V> w^,*-TW7i'laii iv '*----r n i n i " ~~i ^ i 'ifi'M i CJnu''7rt'r~r~r^~^* } FORM 2 This Form applies to absences of 8 calendar days or longer on account of sickness or non-industrial injury among the group of workers under observation. The Form is designed to carry information on those absences which may have begun at any time and have not as yet terminated. The absences are, therefore, those whose records are carried over into the month following the current reporting month. Instructions COLOR: Insert the appropriate letter. O = Other. W = White, N = Negro, SEX: M = Male, F = Female. AGE: Enter age in years at last birthday. DATE ABSENCE BEGAN: For example, 10-14-40. REASON FOR ABSENCE: S = Sickness, N = Non-industrial injury. DIAGNOSIS: Give the primary cause of disability; complications should also be recorded. i' .w i Division of Industrial Hygiene, National Institute of Health, !?; i United States Public Health Service i 3 t Figure 4. -- Back of Form 2 25 oi 129 W.W.IW K rr DR. LANZA: The next paper is by Dr. Gardner, dealing with research at Saranac Laboratory. INDIVIDUAL SUSCEPTIBILITY TO TOXIC DUSTS DR. L. U. GARDNER* I am going to talk to you this afternoon on one phase of the activit; at the laboratory which I believe may have some practical significance, is the one question as regards silicosis which I still believe needs furth clarification. We have a good deal of information now on this subject. If we coo put that information to work in most places we would be able to contr silicosis pretty effectively. However, whore funds are not sufficient to ins: tute all of the methods of control that are known, we are pretty apt to hasome silicosis persisting. For that reason I believe that it would be important for us to kuo whether there is such a thing as individual susceptibility to the action i silica dust, and, if it exists, whether we are able to detect it by any metric If this were true, it might be possible in the pre-enipJoyment examir.atic to discover the individuals who are unduly susceptible to silica dust and it action and to place them in jobs where the exposure would not be as great. There seems to be more or less evidence for thinking that reaction : silica dust, like reactions to other environmental conditions, may not be tk same in every individual. It is pretty common experience that out of an; group exposed to silica dust only a small proportion of that group will react With the high silica exposures of hard rock mining, we find that pretty mud the world over only about a quarter of groups, as a whole, develop demon strable silicosis. It is also true when we break down exposures for individual groups that we find that the longer men have worked the more of the particular group will be involved. It is also true that the higher the concentration of silica in the atmosphere, the greater percentage of the group will be involved. Even with these reservations, we find that there are some men who have worked all their lifetimes under conditions that seem to involve pretty severe exposures and yet they have escaped. It is also true that there are some individuals who seem to be exposed to relatively slight amounts of silica dust and yet in a very short period of time, long before any of their fellow workmen, these individuals develop advanced stages of the disease. Slide No. 1--Classical nodular silicosis in the lungs and lymph nodes of a granite cutter employed in Barre for 12 years. Slide No. 2--No evidence of silicosis in the lung but some nodulation in the lymph nodes. This subject had worked for 28 years in the same indus try with apparently equal opportunities for inhaling granite dust but no pulmonary disease developed. Slide No. 3--A higher magnification of the lung shown in slide 2 to indicate the localization of the dust cells in the walls of the bronchioles and blood vessels. director. The Saranac Laboratory. 26 0 -i J. s% ?*n> 'iTniS7*n>i irt'~ ------------"^nTi - > y r i T T ' * j r v y " 1',/;. *, % Slide No. 4--A still higher magnification from the same lung to demon strate the quantities of dust in cells collected in a blood vessel vail. The shadows of such perivascular accumulations are responsible for the pattern of exaggerated linear markings seen in an x-ray film of the lungs. Slido No. 5--The usual picture of the modified silicosis seen in iron miners who have drilled in rock formations. History of such drilling for 30 years. Slide No. C--Minimal silicosis, too slight to be demonstrable in ante mor tem x-rays, in an iron mine>- employed in the same mines, at the same job, for 30 years. Most of the reaction con>ists of foci of p'gmentatiA'without fibrosis. Only 2 or 3 minute nodules of silicotic fibrosis are seen in this entire section. Slide No. 7--A localized focus of tuberculosis in another part of the same lung shown in slide 6. Here the presence of preexisting tuberculous reaction has caused the retention of unusual amounts of inhaled silica . and iron resulting in localized silicotic nodulation. The silica, acting on the latent infection, has caused it to progress after a time. The section demonstrates a focus of active tuberculosis which is about to break down and form a cavity. During life an x-ray picture would demon strate only the overshadowing tuberculous changes. Vi Slide No. S--Another instance' of the effects of inhaling silica dust into a Jung with a latent focus of tuberculosis. Occupation: sand miner for 15 year's. Death from tuberculosis which progressed fairly rapidly after once it had become reactivated. Evidence of silicotic nodulation largely confined to parts of lungs about the old focus of infection. Slide No. 9--Another section representing conditions in other parts of the lung whose apex is shown in slide No. 8. Here the changes are very x largely due to tuberculosis and only a few of the smaller nodular areas are silicotic in origin. An associated lymph node reveals extensive silicotic changes. Presumably there was insufficient fine, silica dust generated in this occupation to have affected abnormal subject. The individual illustrated retained effective quantities only in the region of a partially healed tuberculous focus. In this locution, however, the dust was dangerous because it presumably caused a latent infection to become progressive. Slide No. 10 shows the complete absence of silicosis in the lung of an individual exposed to dust containing calcined gypsum and quartz. There is a slight amount of pigmentation about the lymphoid tissues within the lungs but no fibrosis. In the lymph nodes at the root of the Jungs arc clusters of silicotic nodules. In spite of a theoretical silica 1 hazard which caused us considerable concern in surveying the plant where the man had worked, r.o effect is apparent in his lungs. He has no scars of old tuberculosis and his lymphatic system has drained away such silica as he has inhaled. Only his lymph nodes show evidence of reaction and in this location the effect is harmless. Slide No. 11 comes from the lung of a man with a history of exposure as a sandblaster for 7 years--part of the time with improper protection. He had been previously employed for 6 years in a railroad shop and before that had worked 8 years as a coal miner. An ante mortem x-ray of his chest showed no evidence of nodulation. This section, typical 27 0 * i rv A iidi --. .1-' \ * -V '*- :. of the vest of his lungs, reveals only minute areas of black pigmenta tion without fibrous reaction. There is no evidence of silicotic nodulation. Apparently his previous exposures had conditioned his lungs to the silica subsequently inhaled in sandblasting so that they did not react by forming fibrosis. While there had been some dyspnoea the man was well along in years and it is doubtful whether inhaled silica was the cause. The slides just shown are examples of the absence of generalized reac tion in the lungs of individuals exposed to concentrations of silica dust that are theoretically hazardous. In most cases the exposures are known to have produced silicosis in other men exposed. In these cases they have either caused no silicosis or only localized reactions about areas of infection. In the last two cases the influence of other minerals in the dust were probably responsible for inhibition of the silica, in No. 9 the effect was probably chemical inside the lungs and in No. 10 atmospheric phenomena presumably prevented silica from being inhaled. Slide No. 12 is an example of the reverse where silicosis develops rather rapidly in only an exceptional member of a group. This young man, still alive, had worked for 5 years in several talc mines where evidence of typical silicotic nodiilation is never found. He then began drilling in a hard rock mine but was not examined until 3 months later. At that time his chest film showed a well developed generalized silicotic nodulation. It is true that the drilling in hard rock might readily have pro duced silicosis but not after 3 months' exposure. Apparently the prev- . ious exposure to talc had conditioned his lungs so that they reacted with surprising rapidity to subsequently inhaled quartz. One might also ; imagine that his tissues were unduly susceptible to silica for others in his location with similar histories have not had the same experience. There are various theoretical explanations which have been offered for these appearances. It is generally considered to be the case that these indi viduals who do not develop disease, in spite of their apparent exposure, have worked in parts of the plant where they do not get as much dust as their fellows. Sometimes that may be the case. Sometimes it may be true that the modifying action of other minerals associated with the silica in the atmosphere may have prevented these individuals from getting as much dust. But it is pretty hard to understand why those protective actions, about which we know a little, should be exerted on one individual and not on all members of the group. t i The other possibility that we have to think of is modifying host factors. Lehmann, as you recall, proposed the hypothesis that some individuals had better noses than others. In some instances the nose would filter out a good deal more dust than another and prevent it-s being inhaled. He made sonic rather elaborate measurements of the amount of filtering action of the upper respiratory tract and thought he was able to correlate the amount of pul monary reaction with the effectiveness of the nose as a filter. Professor Drinker and his students made a similar study among granite cutters. They were not able to confirm these findings of Lehmann's as fully as they would like to have done. Another possible host factor is that of coincident infection of a chronic nature. We all know that scars in the lung of old tuberculosis tend to hold and retain a good deal more dust than normal lung tissue does. 28 It is a very I 0 o oy A t, ' yi'J ~ --*-iVi - 1 .oj.iuj*`i ; "vj--j-f 1 - -r , JV Ilk familiar experience to all pathologists to find in the top of the lungs old scars that are deeply pigmented ly the soot and coal that most city dwellers inhale. It is also common experience to find variations in the amount of dust that is eliminated from the lungs by the lymphatic drainage system and deposited in these lymph nodes. Presumably, then, infection may have two effects. It may hold the dust in the lung locally. The infection may also disturb the function of the lymphatic drainage system ami prevent effective elimination. Then there is, finally, a third general possibility. That is that the tis sues of some individuals are basically more able to react to the stimulus of silica than the tissues of other individuals. The Saranac Laboratory, during the past year, has been carrying on a more or less detailed investigation of these possibilities to find out whether any of them are capable of absolute proof. We have in the laboratory, as you know, dusting chambers where we can control pretty well the atmos pheric concentration of dust to which all members of the large group of animals are exposed. We are making dust counts at very frequent intervals in different cages and in different parts of these rooms, so that we know just about what the dust exposure is. In spite of those controlled conditions we find that normal animals ?vn/--<-.d for the same periods of time do varv in their capacity to react. This is especially true of animals with long tracheas, like the rabbit. It is not so true of the smaller rodents, like white rats and guinea pigs. In the next slide which you will see I want to show you the variation in the reaction in rabbits after four and a half years' exposure to a concentra tion of one to three micron quartz particles averaging 144,000,000 per cubic foot. The amount of dust varied from time to time, but the concentration throughout the different parts of the room was essentially so similar that I don't think the differences were significant. We will see in the animals' lungs differences in reaction. I will say that there are thirty rabbits in this experiment and these represent the variations in the picture which one sees. They all have been exposed to the same quantity of quartz under as nearly identical conditions as we could produce. Slide No. 13--This one has a heavy generalized discrete noclulation through out his lungs. Another on this slide has a slighter degree of the same reaction, and another has nothing that I could identify as silicotic. Slide No. 14--We determined the amount of quartz in these animals' lungs, using x-ray diffraction, which we have been doing recently, and we found that the amount of quartz is comparable to the amount of reac tion present. Here is the first animal, with the two quartz lines showing very strongly, corresponding to the heavy reaction. The second animal has a smaller amount of quartz. The third shows just a faint sugges tion of the heavier quartz lino. It is very, very slight .in amount. Some animals vary in their response even though the concentration of dust in the atmosphere is pretty constant. We find that the amount of variation is greater as the quantity of silica from the atmosphere decreases. We found with our mixture of calcined gypsum and quartz that not more than a quarter or perhaps a third of the animals developed any silicosis. This type of observation seems to indicate that host factors rather than environmental factors must be responsible for this variation. In the animals 29 that I have just shown you the factor of infection has been excluded, haven't discovered whether there is any variation in the structure of upper respiratory tract in these three rabbits or others like them, h pretty difficult thing to do. Wo have tried to find out, but without r. success. Wt. have thought of the influence of differences in the efficacy of lymphatic drainage system of different animals. We are attacking problem by comparing the relative amounts of silica in the lungs and k; nodes of animals exposed for the same period of time under practie identical conditions. We have also considered the possibility that the di: ence in the amount of disease may be due to variations in fundamc. capacity of tissues to react. I shall show a few illustrations of our v. in these fields. In Slide 15 you see an example of the effect of a healed tuberculous sea: retaining dust within the lungs. The scar, which extends from pleura to the root of the lung, is heavily pigmented with iron <1 Similar effects have been illustrated by the cases with more active fection just shown. I have indicated that possibly such retention is due to interference v. the function of the lymphatic system. We can see in this case that fibrosis involves the lymph nodes draining the pigmented part of the 1Possibly the central obstruction in the node or the pressure on the del:, lymph vessels inside the lungs has prevented elimination of the inhaled d- These effects all have to do with chronic infections but the acute . are also puzzling. One frequently sees very little dust in the lungs of a mals dying of an acute pneumonia at the end of a dust exposure of 2 cr years' duration. The infection has apparently lasted only a few days a could have exerted no effect upon the dust inhaled previously. Was : infection present in latent form from the time when the animals were picin the dust room, or did these particular individuals possess some pectilk ties which prevented dust from accumulating in their lungs? Slide No. 16 illustrates the effect of subacute bronchitis in white rats excluding dust from the lungs. It demonstrates the effect of expoito quartz dust in four of these animals. Two with no trace of infect: present well-developed silicotic nodulation; two more with subac. purulent bronchitis show none. Apparently the secretion in the bro;x has prevented effective quantities of silica from entering their lun? In view of such observations"in animals it is possible that the chrobronchitis of which human silicotic subjects complain may be a rr tective mechanism. We have also considered the possibility of valuation in innate capac'.. of tissues to react to silica. To make certain that the same quantity * quartz particles reached the tissues of every animal we have employed ' intravenous injection technique mentioned by Professor Drinker this imp ing. We have substituted guinea pigs for rabbits because we could aff"~ to use a much larger number of animals. First we determined the mini'-' effective dose of quartz that would produce reaction by this pathway. T'' we injected 100 of these animals with a measured quantity of a suspeti?.* of carefully graded 1 to 3 micron quartz particles. All of them will be ki` after or.e year and their spleens, livers and lymph nodes will be ana!y-" individually for their silica content and degree of tissue reaction. 30 Slid No. 17 shows the device of variation in the amount of silicotic fibrosis observed in three of the guinea pigs used in the preliminary test to establish a proper dosage. Ill-action is illustrated in the livers 8 months after the injection of 50 mg. of 1 to 3 micron quart?:. One of them has barely visible foci of reaction scattered through it. The second has somewhat larger ones and in the third the nodules are very obvious. Chemical analyses indicate that these quantities of silica in all three livers are apparently adequate to have produced a maximum reaction. Confirmation of these results in a much larger series of animals would indicate that more subtle variation? in capacity to react to silica are responsible. "We have tried to find out wherein these differences might lie. We have felt that possibly the diet of the animal might affect its capacity to react. It has been claimed that in the presence of a vitamin C deficiency scar tissue forms les? readily than on an adequate diet. As a consequence we have put some animals on a C deficiency diet, exposed them to quartz, but we have found ho difference in their capacity to react. For this reason, I think we V can exclude C deficiency. Then we tried vitamin B and its effect. We did this because some one had shown that feeding high vitamin 13 diets would prevent the development of cirrhosis of the liver by various irritants. We were getting cirrhosis of the liver by injecting quartz into the blood stream, as Professor Drinker showed you this morning. Feeding vitamin B did not do very much. It prevented the most widespread and destructive changes in the liver, but it did not prevent the formation of these nodules in the liver, such as you have seen here. This work is still in progress. It looks to me now as if the variations which animals and human beings undoubtedly do manifest were pretty largely due to host mechanisms rather than environmental factors. It looks to me as if possibly the effectiveness of the upper respiratory filtering mechanism were very important in determining whether one individual got more dust than another. I also feel, however, that the effectiveness of the lymphatic drainage mechanism has to be taken into account, that old healed infections may alter the effectiveness of drainage and allow more dust to stay in the lungs. Just what this last observation will eventually turn out to mean I don't know. We are going ahead and as soon as these hundred animals have had a year's contact with quartz we will make our analysis and draw our con clusions. Whether we will be able to apply any of this work in pre-employ ment examination I do not know. But it does suggest that respiratory infec tion, even though it is inactive, may be of importance. I have illustrated one line of- research which has been going on with your assistance at the Saranac Laboratory. There are ma.ny other subjects that I could have chosen to discuss. Perhaps some of them would have inter ested you more. We have work progressing in the field of asbostosis, which I think is going to be of definite significance as to the etiology of this disease. The fourth year of this program is just about completed. There is still more to do. We have been studying the effect of carbon arc ash of low concentration, similar to that to which motion picture booth operators may be exposed. Nothing has happened, as one might anticipate. We have been working on the effect of inhaled glass wool. Apparently 31 0 i : i o O 0 * even the finest textile glass set up as an atmospheric dust is not inhale** appreciable concentrations and does not produce any dangerous effects li the lungs. As Professor Drinker indicated this morning, 1 believe there is a r. field for investigation of the effects of various respiratory irritants i;-. tuberculosis. I have been so impressed myself, as probably most of v have, with the growing importance attached to tuberculosis in ind.i-t that we have proposed this year, in place of the regular silicosis sympo-iwhich wo have held from time to time in Saranac Lake, to offer a sympo-;_ on this subject. There seems to be a very considerable interest in the pr-.lent and I think we can assemble a group of speakers who would makedefinite contribution. The symposium might be developed along the following lines: An introductory review of the fundamentals of tuberculosis and i diagnosis; the routine methods of control; a discussion of the known fac influencing tuberculosis susceptibility, theoretical as well as practical. Then a presentation of conditions in different industries where statistic; evidence *?.tes that the tuberculosis rate- is hign; an analysis of tlv.-- industries to discover whether industrial factors arc responsible. Finally, a discussion of the subject of control from insurance and com pensation angles. If there seems to be a sufficient interest for such a program the Sarar.i Laboratory probably will offer it some time during the early part of June. DR. LANZA: Wc will now have a discussion of this paper. I do hop-, .4 that you will ask Dr. Gardner such questions as may appeal to you. DR. DAVIS: I should like to ask if in the development of this worl there doc-s appear to be another illustration of what Jerome Alexander l:.v spoken of as the "optimum colloidality." He points out that a great man; phenomena, when plotted against particle size, as you go down in panic's size go up in intensity. As I understand the discussion this morning, you. get a marked increase in the silicosis effect when you reach a particle size of three microns or less. Then away over on the other side you have practically none at all. I wonder if that might represent a method of attack or if it has already been proved or disproved. A further factor that seemed to occur this morning is this. I wonder f if there is an item of crystallinity in our silica. We know we have silica occurring in different forms. Cristobslite is the only one I happen to remember now. I was wondering if'the effect had been associated with or.* or other or is it independent of the crystalline forms of the silica presented Arc there manifestations that that may be a suitable attack? I personally would be greatly interested if you could outline, if possible. . those materials which when added to quartz, such as quartz and asbestos. . which you mentioned, give silicosis reaction and some similar material5 ; which do not give it. | I-hope I haven't covered too much ground. t DR. GARDNER: The first question dealt with variations according to particle size, such as Professor Drinker discussed this morning. I think that is unquestionably true. The smaller the particle injected into the tissue the more active it becomes. As far as inhalation is concerned, presumably there is an uncstablished lower limit of particle size beyond which we do r.ot 32 OiiSG ; 1 i * ---------- - T - 111V1 * i~'i I'-* I '"*! 1*1 4 have to be concerned, because the particles smaller than this minimum si2e wiJl be exhaled again about as fast as they are inhaled. Hut in the inhala tion experiment which l was discussing I don't believe that the matter of particle size was responsible, because we have made size frequency determin ations of the dust in the atmosphere in these rooms and wc find a sufficient quantity of fine particles at all levels in our dust house to produce disease. The capes are not over five feet above the floor in any place and the lowest one is about eighteen inches above the floor. Furthermore, the animals arc moved around from time to time, so that they have exposures at different levels. I therefore feel pretty strongly that it is a difference in host factors that is responsible for the variation in the animals' lungs that you saw rather than any difference in the atmosphere or in any dust in the atmosphere. All this dust has been ground first and all of it is agitated in a hopper. The room is not over eight feet square and eight feet high. The chances for variation in atmospheric concentration are pretty slight. Does that answer that phase of the question? DR. DAVIS: Yes. DR. GARDNER: Would you mind repeating your second question? DR. DAVIS: Crystallinity. DR. GARDNER: We have tried a great variety of free silicas to see what their effect might be by injection techniques that already have been discussed. We have found that normal quartz, the cryptocrystalline free silicas and the vitreous silicas, cristobalitc and the other inversion form, tridymite, are all equally active; that of the amorphous silicas only diatomaceous earth produces a silicotic type of reaction. Opal, which is now reclassified as cryptocrystalline rather than amorphous, as they used to tell us, will produce a moderately severe type of reaction when ground. All of these tests were made with materials ground to one to three micron particle size and all injected in the same dosage. As far as I can see any inversion forms of quartz are just as active as the norma! quarts itself. Then you had one other question. DR. DAVIS: Are any of the silicates-- DR. GARDNER: None of the silicates, by the injection tests, have given a significant degree of reaction. A fe\v of the clay minerals will pro duce a chronic inflammation but this is not generally a severe one and does not progress to the formation of scar tissue. I think there is. however, a. very real and urgent excuse for doing an inhalation experiment upon the clays, because clays have such a varied industrial use and because so many roentgenograms come to us of men who have been exposed to clays either in refractories industries or in potteries. These roentgenograms show shad ows. The roentgenologist is quite sure that the industrial exposure is responsible. There have been no autopsies reported on human beings ex posed to clay alone. We don't know the basis of these shadows. In many instances the exposure has been not only to the clay but to flint and various other forms of free silica. We may be seeing the effects of combined expos ures to quartz and clays. I am quite sure that were it possible to do inhalation experiments with pure clays, both of the refractory group and those used in the potteries, we S3 0 37 r-.'.VS# as. a, 1 1 * -fiV.WTVrfa Ai< 1 i i : 1 V J . i ,vf >' V -f- ;> would have sonic valuable information. 1 think probably what would f, pen, us the result of our experience with injections, would be that we w., see in the lungs evidences of sliglit amounts of chronic inflammation i that these chronic inflammatory changes would not be associated with ! nile fibrosis; they would not give rise to conditions which were disable However, this needs verification ami needs proof. The only way I know getting it is to do it by inhalation rather than by injection. Of course- we do have too the effects of mixtures of the sukstnnemixtures of free silica with other materials, like clays and many <>tl things, that will modify the picture. J was talking at lunch this noon u group interested in iron oxide and recounted an experience which we had h. We injected one group of animals with a mixture of equal parts of heme.:, and quartz ground together dry in a ball mill. Injection of a saline susp. sion of this material caused no reaction whatsoever. In the second expo ment we ground the two substances separately, then mixed the suspense of particles together and injeeted the same quantities. We now got progressive silicosis. The same amount of quartz was there in both instances, but the meth of treatment in the first case had neutralized the quartz. It had simp plastered the surface of every quartz particle with a thin layer of ir. oxide, which had prevented reaction. It is obvious that effects like this may occur in the process of grindh in industry and that inactivation of quartz does occuf, so that'the story isr as simple as just having a given amount of quartz particles of a given si and a host exposed to it. MR. ItOUTSOXG: I. was very much interested in the slide which had do with the sand blaster's lungs and his previous industrial history. Yc said that the previous history had conditioned the lung to resist sjlicos: Could you expand that a little for us ? DR. GARDNER: I wish I could. I was trying to cover my ignoraru with a phrase. I don't know wliat happened. AH I know is that that hr had, by chemical analysis, a very appreciable and what I felt was signifies.: amount of quartz in it but there was no evidence of specific reaction t that quartz. Now it might be that through the mechanism of the body ce: the coal dust became applied to the surface of. the quartz grains and tr quartz no longer reacted. Years ago Dr. Haldane called attention to the same thing. He had set a few cases where men were exposed first to coal dust and then to quart, and nothing happened. He thought that the effect was due to stimulate of phagocytes which carried the quartz out of the lung, because the ccc had stirred up these dust cells to carry the stuff out. The effect isn't asimple as that, because we know the quartz is in this lung. Chemical analy sis shows it is there, and yet no reaction has developed. It may be that we have something taking place in the body comparable to that coating of the quartz that I just described by mechanical grlndia? We know that the body tends to bring inhibitory substances into the sar. locations as the quartz, which prevents irritation. We have done quit a bit of Work, which I have discussed here before, with aluminum hydros?" as inhibitor. We can put quartz in the body by one pathway and alumina: hydroxide by another and, provided the pathways are such that the t* substances get into the same organ, inhibition results in no silicosis wh.~ 34 0 : X : JL o Q ) *"' 7." : :v-" i `hi ifcni'nr.fi) hi aiui soever. 1 presume that something like that has conditioned this sand blast er's lung. MR. KUMLER: Dr. Gardner, do we have to change our counting tech nique in the case of silica in order to more accurately estimate these three to one-half micron sixes? DR. GARDNER: I doubt whether we will. As Professor Drinker said this morning, our method of control seems to work. Probably it is suffi ciently accurate to establish what we need to know about dust in the atmos phere. If these very fine particles which can only bo seen by dark field or some other technique are actually retained in the lung the scientist would like to know how many of thorn there are there, but the engineer probably >* doesn't need to know because his present rules of thumb seem to take care of the situation. We know, as a general vule, that rather constant ratios exist between dark field and light field counts. Generally the dark field count is three to four times that of the light field count. We still use dark A -e field counts for cur experimental work and in some other places. If we find a disturbance in that ratio and there are many times more dark field parti cles than those observed by light field, we think there is sanitary signifi cance to the variation. But I doubt whether it is necessary to change. * 'it DR. HAYTHORX: I should like to add one comment. I have seen a .._2 :j5 number--I wouldn't say a great number, but I have seen several lungs from the coal mines around Pittsburgh which show practically the same picture that we have just discussed. That is, there is plenty of pigment there-- coal pigment, I think, largely. We incinerate the sections and put them under the petrographic microscope. There are plenty of silica crystals there and yet there is no nodulation in the lung. That has caused me to wonder what is the difference--the actual differ- .. ence--between silicosis that is prominent, as Dr. Lanza himself has shown .* in his surveys, in the anthracite mines in the east and the bituminous mines f that we have in this district. We do get the silica inhaled and we do get the carbon there in large quantities. While I have seen more of it sir.ee -V they have been sending in a good many lungs on account of compensation than I did previously, the actual silica nodulation is not common in this dis trict in coal miners' lungs, as compared to those that are reported from the eastern part of the state. On the other hand, we just had a sand blaster's lungs, within the last two weeks, that is as typical a case of silicosis as I have seen. There is something in connection with that soft coal'dust- inhalation and the pres ence of silicosis in the lungs and its effect. DR. GARDNER: I suspect, Dr. Haythorn, that some day we will have a method of determining the physical relationship of the silica to the other minerals and perhaps we will find a way to discover whether coating effects actually exist or not. I really believe that is the explanation. How it comes about I don't know. DR. LANZA: Are there any more questions? Thank you very much, Dr. Gardner, for your paper and your discussion. The next paper is the account of the research that has been carried on in the University of Pennsylvania, by Mr. Haagensen. 35 0 j_ j. 3 9 FURTHER DEVELOPMENTS OK THE OBSERVATION OF THE REACTION OF LIVING TISSUE TO. SILICA GRANULES IN THE LIVING MAMMAL ELIOT R. CLARK, M. D.* and HARROW E. HAAGENSEN, M. S." During the past year additional work on the observation of the reacUo: of living tissue to silica pinnules in the Sandison-Clark rabbit ear chambchas been carried out along two lines. First--A more detailed study of cellular reactions has been recorded particularly with respect to macrophages and giant cells. Second--An additional sample of silica obtained through the courtesy o: Dr. L. U. Gardner, Director of the Saranac Laboratory, lias been used. Thi. sample was lOOG SiO., of particle size 3^ or less in diameter. The results may be illustrated by a number of slides considered to fc. representative of the large number of photographic records obtained in tL past 12 months. Series A # This series of slides at a low magnification illustrates two points: Slide 1--The vascular pattern was growing downward. This exposur-. was taken immediately prior to insertion of the silica particles in the chamber. Slide 2---Four days later the blood vessels and the connective tissue have grown downward leaving one of the silica fields in a vascularized area. Slide 3--Nine days after the insertion of the silica particles the blood vessel pattern had started to grow through the large central field of.silica. This field of silica had been inserted purposely in a lower region containing only extravasated material, the result of the original insertion of the cham ber in the car. Slide 4--On the 18th day, the large field was above the growing edge. However, as the first point, the growth of blood vessels and connective tissue had not been influenced by the presence of the silica in this centra! field. If the silica particles had through some mechanism caused rapii connective tissue growth the growing edge would have been uneven in tincentral region. This was not the case. Slide 5--On the 68th day the chamber connective tissue bed had a clear space because of the retraction of the tissue near the growing edge. Slide C--On the 93rd day this space was completely filled in by the production of connective tissue fibers through the activity of the fibroblasts normally found in the living tissue. For the second point of interest, while the rapid tissue growth took place to fill in the space, there was no indica tion of unusual connective tissue growth in the region of the large centra! silica field during the same period of time. ' Series B However, this series of slides at a much higher magnification illus trates tissue response to a relatively small field of silica. IVpartmvnt of Anatomy. School of Medicine, University f Pennsylvania. (Road by T>. E. Ha.iRenscti.) 36 w 4 3 Slide 7--In this slide the particles were scon 7 days after placement in the chamber. They were widely dispersed, mostly within the phagocytic cells. Slide 8--On the 24th day the grouping effect of these silica-laden cells was seen. This point has been cheeked a number of times in other chambers. Slide 0--On the %th day the field of cells was dispersed. The connec tive tissue pattern was not influenced by the presence of the silica field and there was no indication of a concentric arrangement of connective tissue fibers. Series C Slide 10--This scries illustrates the tissue reaction with a larger field of silica in the same chamber. In this slide the field was on the 7th day fairly evenly distributed. Slide II--On the 45th day the field was in the stage of aggregation of the living cells with their contained silica. Slide 12--On the 95th day the field was again in the dispersed phase. There was n indication of a specific response on the part of the fibr'4U--t Scries D For contrast this series illustrates the tissue reaction to a comparatively very large field of silica particles varying widely in size, however, of which 87.55} were under 6m in diameter. Slide 13--Fifty days after insertion the connective tissue bed along the periphery of the field was uniform from left to right. Slide 14--On the 71st day the field appears relatively stable. Slide 15--On the lOStli day the connective tissue formation in this region was not greatly changed. The silica field was dispersed. Slide 16--The same day another exposure in a region free of silica was taken. The connective tissue differentiation from left to right appeared similar to the field of the previous slide. Series E Slide 17--For purposes of comparison 2 slides are shown of the reac tion which followed the use of the 2 silica samples. This slide from a cham ber in which silica sample A was used was taken 151 days after insertion of the silica. Slide 18--This slide from a chamber in which we used silica sample B obtained from Dr. Gardner indicates the tissue response 353 days after insertion. Series F For a period of 8 weeks the movements of a large multi-nucleated giant cell containing a number of small silica particles were recorded. Slide 19--On the 46th day the cell was rather faintly visible with the previously ingested small silica particles. Slide 20--On the 71st day the cell was larger in diameter and the silica particles were more clearly defined. The cell had moved upward over a large venule. 37 0 J.V ir.zTji: n* nr iitia IW Slide 21--On the $2nd day the cell showed signs of degeneration. The boundary was indistinct and a number of macrophages were sticking to the periphery of the cell. Slide 22--On the 108th day the cell was obliterated. The silica parti cles which had been ingested S weeks previously were then either deposited on the connective tissue bed, or taken up by phagocytic action of macro phages. There is no evidence of any irritating residue left by the degener ation of the giant cell. Motion Pictures Several references in the literature on silicosis indicate the sticking of leucocytes to the endothelial colls lining the blood vessels in regions where silica particles are present. The film about to be shown was taken of a silica field in the living tissue of a rabbit ear chamber. The incorrectness of that conclusion reached from dead tissue studies of rabbit ears is evident from the film. The silica had been placed in the chamber several weeks previously. The last part of the film was taken of another chamber by Dr. Clark. This illustrates sticking of leucocytes caused by artificial means and not bv the presence of silica particles. Conclusions It may be concluded from observations for a period as long as 370 days following a single insertion of silica granules in a series of rabbit car cham bers that the following points are evident: The endothelium of the very extensive complete vascular system found in various chambers does not show increased growth or differentiation into epithelioid cells. The granular, leucocytes do not show a specific response to the silica particles. Neither the lymphatic capillaries nor their contained cells show a spe cific response to the presence of the silica particles in the living connective tissue. Visible reaction to the silica has been almost exclusively confined to macrophages. As described last year, these cells take in or phagoeytize the silica granules in varying numbers, and retain them for weeks or months. They become very sluggish in their movements and show a pronounced ten dency to form permanent groups in the tissue spaces. Such groups have been followed for nearly a year without showing any significant changes. During the first few weeks, before grouping has occurred, and in lesser degrees in later stages, there are seen many giant cells. They do not develop until after the macrophages have taken- up most of the silica, and are prob ably formed from macrophages, either by coalescence -or by nuclear division, as W. H. and M. R. Lewis have described. While they may contain large numbers of silica granules, the evidence indicates that these granules have been taken up by the individual macrophages, and not by the giant cells themselves. Giant cells may persist for days or weeks, during which time they may manifest a very slow amoeboid movement. They may then dis integrate, the remains being taken up by new macrophages, or the silica granules may be left in the tissue or incorporated in connective tissue fibers. Following the disintegration of giant cells there is no visible evidence of a deposit of any irritating residue. , It should be pointed out that giant cells are invariably observed in the 38 'A \J a. ') J IK.UIII.4 1 .W^r'tl,71, *~ Awrvir.'^.- t-.l11.'.*1. i- -1 "M * <**;. v'>. .2; s*. c; . * *T ~ r- A % ** v* -x* *' .^.rn I -1 n,nn farVAsagg t The the rtiitod ;roicr- : of ere f a ess ent eks Dr. ans lays ara- und into ilica spetive 1 to the iths. teniave sser elop robion, irge iave tells -ime disilica ers. ? of the v E chambers in the rabbit's ear whether or not silica granules are present. It should also be mentioned that the supply of macrophages is probably inex haustible, since they undoubtedly come from the large mononuclear leuco cytes of the blood stream whose number remains constant normally, with replenishment to excess following depletion. The pattern of the connective tissue growth in the neighborhood of the silica injections shows no noticeable difference from that in other regions, or in chambers without silica.. Whether the groups of silica-containing cells are large or small, nothing has been seen, cither in our living specimens or in those of our preparations which have been fixed and stained, which indi cates even a tendency toward the appearance of the typical silicotic nodule. DR. LAXZA: This very interesting paper will now be discussed by Dr. Eliot R. Clark. DR. CLARK: The results of these experiments are not considered by us to be necessarily in conflict with the results of the injection experiments of the many investigators who have described the formation, in rabbits and guinea pigs, following intravenous (Gardner, Simpson and Strachan), intraperitoneal (Sayers and Miller) or subcutaneous (Fallon and Banting) injec tions of silica* of characteristic nodules closely resembling the silicotic nod ules found in the lungs in cases of silicosis; and who failed to find nodules of similar character following injections of many other types of granules. Rather it seems to us that the absence of the typical reaction in the particular set-up of our experiments furnishes an unusual opportunity to investigate the various possible accessory factor or factors which apparently must be added to the simple long-time presence in the tissue of silica gran ules, in order to produce typical silicotic nodule formation. That the complete explanation has not yet been found is evidenced by the variety of unproven hypotheses which have been proposed. These in clude among others: (1) the possible slow dissolving of the silica with pro duction of colloidal silica which may have an effect upon the tissues; (2) some sort of slowly developed direct toxic action of the silica which eventually injures the cell; (3) the production by the cell of a phospho-lipid which becomes the irritating substance; (4) the suggestion that the silicotic nodule is produced not in reaction to silica alone but to silica along with something else: living bacteria such as tubercle bacilli or their products, gaseous substances, or various other chemical substances. Each of these hypotheses is held by one or more active investigators or group of active investigators at the present time. All of them are. in need of crucial testing. In anticipation of the desirability of having available an arrangement by which, in addition to having access to the living tissue for the insertion of granular substances, we might have a container, open to the tissues, we have developed a combination chamber which makes this possible. Without mechanical disturbance to the tissue, we can place in the container any desired chemical substance, can leave it, as long as desired, in contact with the tissue, nrsd can then recover the contents of the chamber for chemical analysis. The device, which is an adaptation of one in successful use for some years in our laboratory in the hands of Dr. Abell, solves the problem of a way to subject tissues to the prolonged action of fluid substances, which (Fallon and Bunting ch-nril.e nodtilt-s formed in the can* of rabbits six months after single suboitt:m<<!* Injv-ctlmm rf *ui<-n. and (-notion against th- use of too large a dose--in which c.-i-e the granular masses sc-cm to act only as foreign bodies.) 39 i?. f T.1T IrUi tiS&e*n I 1 J i J ii 5 . \i i <. cannot be achieved satisfactorily by subcutaneous, intravenous or intraperitoneal injections. With this new chamber we can, for example, subject to a new test the question of the reactions of living colls ami tissues in the living animal to a combination of long-retained silica granules and freshly introduced colloidal or dissolved silica; we can study the reactions to phospho-lipids; we can observe the effects, on the cells with long-retained silica granules, of living or dead tubercle bacilli or their extracts--to mention only a few of the possi bilities. A rabbit with this new chamber installed is on demonstration at this meeting. There is reason to hope and to expect that, building on the foundation, already laid in the studies which have been reported today and at last year's meeting, vc may be able to make further contributions toward an under standing of some of the puzzling problems presented by the reactions of living tissues to silica dust. DR, LANZA: Is there any discussion now or any question on cither of these two authors' remarks? DR. GARDNER: I show this slide to illustrate different stages in the reaction to direct injection of larger quantities of 1 to 3 micron quartz particles. The early phase consists of a tubercle-like collection of macro phages or dust cells filled with quartz of the same size used by Dr. Clark. After about 2 or 3 weeks the center of this mass breaks down with the liberation of fatty material demonstrable by special stains. After 6 months the center of the area has become soft and semi-fluid so that it has fallen out in preparation of the section. Surrounding it, however, is a definite layer of more or less concentrically arranged fibroblasts (connective tissue cells). One year after exposure the whole area has been replaced by a mass of silicotic fibrosis, so dense that the tissue is torn in preparing the section. I cannot remember the exact dosage in our experiments but they wore of the order of 0.1 cc. of a 1 per cent suspension, which means an enormous number of particles of the size employed. I believe that the fact that so many observers have obtained silicotic reactions on injecting excessive amounts of silica directly into the tissues while Dr. Clark has failed to do so with smaller quantities indicates an indirect mechanism as the cause of the injury. Fallon proposed the hypoth esis to which Dr. Clark has referred, i. c., that in silicosis the primary irri tant was silica. This substance acting within the phagocyte poisoned it, liberating non-specific phospho-lipids. Phagoeytosed tubercle bacilli might have a similar effect and likewise liberate phospho-lipid. It was the latter substance, non-specific in character, which then acted upon the connective tissues to produce the nodular type of reaction which characterizes both silicosis and tuberculosis. We are testing this hypothesis at the present time. Dr. ClaTk has an exceptional opportunity in the method that he has developed to-study the further stages of the reaction to silica and to test the Fallon hypothesis. I shall watch with great interest the further developments of his work. DR. HAYTHORN: I should like to produce at this time an unpremedi tated hypothesis. Repair and reparative processes, and I think that the nodule of silica Is a reparative process, depend on some injury or destruction of the circula tion. Dr. Gardner's dosage, aside from considering the quantity of silica, 40 0ia4 f -r.n -4^ ******f**-'iiii rwfr`ii>ii n~ L jh. was large enough to injure the local circulation. We can see from the doses used in the ear, in these motion pictures, that the circulation was still intact. It might not amount to anything, hut I should think there was a chance that those, when introduced, should injure some of the vessels. DR. GARDNER: I think, Dr. llaythorn, that you are undoubtedly right. I think that there is an effect on the circulation, but I think it is a specific one, because the same dose of the same size particles of aluminum oxide, for example, will not have this effect.' Nor will the nodule be formed if you coat your quartz particles with aluminum hydroxide or with iron or with any of the other known antidotes. I think the injury is the result of soluble silica continuously deposited on the surface of the quartz grain and that that injury manifests itself on the cytoplasm of the phagocytic cells, dust cells. I quite agree with you that there is an effect on the circulation, because we see the vessels swell out with these big doses. DR. HAYTHORN: On the other hand, if we make a cut with a razor that destroys the circulation, we will get a scar at that point. DR. GARDNER: Surely. DR. CLARK: I should like to say in connection with Dr. Gardner's dis cussion that we have been very much disappointed that we didn't have nice silicosis nodules develop with our method. We thought that here was a chance to watch the development of the nodules, perhaps add something to the mechanism. Then if we could get them produced we would have a chance to experiment with substances that might prevent the development of the nodules. 1 think that we should go on and use more massive doses, although, as you saw from some of the pictures, for the amount of tissue involved some of our doses were pretty large. I still think that the fact that silica gran ules, in the doses that we used, can remain in this environment for months without producing any specific response does furnish a basis for a series of experiments in which we may see what it is when added to that silica-- maybe it is more silica that may be the answer--that does lead to the result of this specific reaction in the connective tissues. DR. MELLER: This is where we have planned to stop for the day. I want to call your attention to the symposium on industrial health defense scheduled for tomorrow, which will be intensely practical. I am sure none of you will want to miss it. w The meeting is adjourned until tomorrow morning. WEDNESDAY SESSION, NOVEMBER 13, 1940 The Wednesday meeting of Air Hygiene- Foundation of America, Inc., was called to order at 10:00 A. M. by ]>r. H. B. Mellcr. DR. MELLER: Mr. Waters is detained in court this morning so we will ask Mr. J. Dewey Dorsett to be kind enough to read Mr. Waters' paper. REVIEW OF RECENT OCCUPATIONAL DISEASE LEGISLATION I r THEODORE C. WATERS* \ The maintenance of the health of workers engaged in industry has become an essential part of the program for national defense nd, during the past year, there K_- '-een extensive activity on the 4>art of Federal, State and private agencies to perfect the methods for health control. These programs have created new responsibilities for employers, and I have ben requested to submit, on behalf of the Foundation's Legal Committee, a report dealing with current developments relating to the legal liability of employers for health injuries sustained by employees. For this purpose I have selected the following subjects for discussion: 3. State Legislation 1. Occupational Disease Compensation Acts introduced in State Legislatures in 1940. 2. Legislative Resolutions authorizing the appointment of Recess Committees to study the problems of occupational disease, and submit reports to the 1941 State Legislatures. 3. Activities of State Bureaus of Industrial Hygiene. :V -L a.v* IX. Important Court' decisions construing compensation statutes. r_ I. STATE LEGISLATION X Occupational Disease Compensation Acts Introduced in State Legislatures In 1940 i No additional States, during 1940, enacted new occupational disease com -7? t pensation statutes and, therefore, there are now twenty-four* States and the Member Legal Committee; Chairman, Maryland Occupational Diseases Com 1 mission. i ' 1. Arkansas-15S5Cftlifornia-1515 Connecticut-1?1"? Delaware-1527 Idftho-1535 tWnols-15?. Jntliana-1037 Kentucky-1531 2. District of Columbia-192S Maryland-1333 Massachusetts-! 532 Michigan-UC." Missouri-1531 Minnesota-!!*?? Nphraskn-1933 New Jevsey-152! New York-1520 42 North Carp!lna-l?3S North Dakota-1535 Ohio-1521 Pennsylvania-1537 Rhode Islartd-153? Washington-1537 West ViiKinfa-1533 Wisconsin-151?' a 1) J*L J*L 4 Vn s-S ; 'j ? ! . x ii . - -=* ft*-- - -t <t--i *rLt. - r- -'-rii-^ii m IT" District o Columbia- whore occupational diseases are specifically compen sable by statute. The State of Arkansas, included in this number, enacted its occupational disease law in 19;'*,lt but this law will not become effective until approved by referendum at the time of the general election this fall.* During the p;\<t year, bills that would have made occupational disease injuries compensable were introduced into the State Legislatures of Louis iana and Virginia, but failed of enactment. In New Jersey, several bills were offered to make the pneumoconioses compensable, but up to the present time none of these bills have been favor ably acted upon bv the Committees to which they were referred. Mew York State enacted an important amendment to the section of the statute providing compensation for the dust diseases. Prior to the 10-10 amendment, compensation for partial disability from these diseases was denied, ar.d a limitation of monetary liability of an employer was established in the amount of $500.00, accounting from June 1, 1930, with progressive in creases at the rate of S50.00 per month until a maximum of $3,000 was reached. That maximum w--sM have been reached in August of 1C 1_, but this amendment increased the maximum limitation of liability to 85,000, the progressive increases at the rate of S50.00 per month continuing until the maximum is reached in December, 1013. This amendment also provides for the appointment by the Industrial Commission of a board of expert con sultants on dust diseases, consisting of three members, who are required to examine claimants in all controverted claims. The findings of this board of expert consultants are then filed with the Commission and become presump tive evidence upon the hearing of the claim. During the coming year, the Legislatures of all the States will be in session, except those of Alabama, Kentucky, Louisiana, Mississippi and Vir ginia, and it is highly probable that bills will be offered to make occupational diseases compensable in some of the States where they are not at present compensable, while in other States efforts will be made to liberalize the laws and extend the benefits of compensation thereunder. I would suggest, therefore, that the members of the Foundation follow carefully these legislative programs in the respective States in which they are engaged in business. 2 Legislative Resolutions Authorizing the Appointment of Recess Committees to Study the Problems of Occupational Disease, and Submit Reports to the 1941 State Legislatures During the year 1940, legislative resolutions authorizing the appoint ment of Recess Committees for the purpose of studying the compensation laws and recommending revisions thereof have been passed in the follow ing States: Louisiana Oregon Michigan Tennessee New Hampshire Texas Utah In Louisiana, House Resolution No. 614 and Senate Resolution No. 387 provide for the appointment of a Commission, to study the workmen's com pensation law and to draft a new Act for that State. To date this Commis- This law was approved In the November, 1910 election. 43 0 i i 4 7 ' w'r '-I sion does not seem to have been active nor to have prepared any report. In Michigan, House Resolution No. 52 and Senate Resolution No. 3S provide for the appointment of a Committee to study the Workmen's Com pensation Law. No personnel was appointed, and the Standing Committees terminated upon the adjournment of the Legislature. The State Lar Associ ation of Michigan appointed a Committee upon Legislation and Law Reform j to study the proposed revision of the Michigan Workmen's Compensation Law. This Committee has been active and, while its final report has not | been submitted, it has prepared and submitted a progress report which | includes the following reference to occupational diseases: i "Your Sub-Committee has under consideration and has tenta- s tively agreed upon the following genera] proposition, detailed * recommendations as to which will be included in our final report: . . "We believe the law should cover accidental injury which may (be definitely, located as to time when and place where the accident occurred, as well as 'v>unatio:disease clearly due to the of the employment. We recommend that the schedule of occupa- ! tional diseases be eliminated from the statute and that the te `injury' or `occupational injury' be clearly defined by statute in such manner as to include accidental injury as indicated above and occupational disease peculiar to and resulting from the employ ment. Such definition should clearly exclude disabilities common to members of the public generally, except where it is clearly aggra vated by the employment." I In New Hampshire, Joint Resolution No. 04 provides for the appoint ment of a Commission of nine men to study occupational diseases. This Commission has been appointed by the Governor but to date has not pre pared its report. In Oregon, House Joint Resolution No. 13 provides for the appointment of a Committee of five members to study the Workmen's Compensation Law and the advisability of including occupational diseases under the act. This Committee is now actively engaged, but to date has not prepared its pro posed report. In Tennessee, Joint Resolution No. 42 provides for the appointment of a Committee to study the Workmen's Compensation Law and presumably to consider the recommendation for compensating occupational disease injuries. A Commission of three men has been appointed recently by the Governor.* -- In Texas, House and Senate Resolution No. 256 provides for the appoint ment of a Committee of five members to investigate the operation of the Workmen's Compensation law. I am advised that this Committee has not been active and probably win not prepare or submit a report because of the lack of an appropriation to carry out its work. In Utah, Senate Resolution No. 249 directed the State Board of Health, in cooperation with the United States Public Health Service and the Indus trial Commission to make a survey of industry in Utah, and to determine the nature and extent of the occupational disease problem it\ that State. It is * The Governor's appointees arc as follows: I>r. Roy C:u iXMt, of TYaUoily College of Nashville. J,ev l.orins:. I.M-or I.earl.i- of MrmpMs. IV. T. Kciin.i ley, n Knoxville attorney. 44 0114 8 % h assumed that the- State* Board of Health will submit to the proper LegisJative Committees a report dealing with this problem at the 1941 session. 3 Activities of State Bureaus of Industrial Hygiene State Indus:::a! Hygiene Units have been established awl are now active in thirty-one States. To this report is appended a list of those units with the names and addresses of their directors. During :h-,- pas: year there have- teen many instances where the services of these units have beer, made available to industry for the purpose of assist ing in the cor.:r>! of specific occupational disease problems. The utilization of these sendees should be of material assistance to small industries with out medical or engineering departments qualified to advise them in the methods of centre.) of disease hazards. The Divisions of Industrial Hygiene in several of the States, during 1940, have promulgated Codes and Buies for the protection of employees from occupational disease injuries. In Xew York State the State Depart ment of Labor has submitted to the Board of Standards and Appeals for approval three proposed industrial codes relating to the following subjects: 1. Control of dust, fumes and gases in foundries. 2. Control of silica dust in the stone crushing industry. 3. Control of silica dust in the stone cutting and stone finishing industry. These Codes were prepared pursuant to Section 29 of the Xew York Labor Law and include standards of dust concentrations permissible in the given industries. Public hearings upon the Codes were held during the past summer and closed on Aagut 1, 194^. The Codes are now before the Board of Standards and Appeals for final action and, upon their approval, will have the force and effect of law. The New York State Department of Labor is now giving consideration to five additional Codes as follows: 1. A Code on temperature, humidity and ventilation. It is believed that this Cede will be very narrow in its scope and will apply solely to underground operations. 2. Revision of Code No. 12 on dust, fumes and gases. This matter is being studied by the Department and additional data is being obtained to lay the groundwork for the new Code. 3. A Code to control dust in the Ceramics industry. The basic data is now being procured for the preparation of this Code. 4. Code or. respiratory protection. The need for the approval of respiratory equipment has come to be recognized and the use of such equipment may be approved and recommended in certain types of industrial operations 5. Carbon Monoxide Code. The proposed study of this subject is being planned by the Department. Mo Committees have as yet been appointed to draft these Codes, and the present departmental activity is confined to accumulating information relat ing to these subjects for the purpose of submitting such information to the Cotie Committee* when appointed. In Maryland the State Department of Health and the Department of 45 ! Health of Enltimnre City have recently promulgated rules relating to per missible concentrations of vapors, fumes and gases hazardous to the health of employees. These rule? have been advertised for public hearing on November 25th, after which they will be adopted or amended.- The proposed rules arc patterned upon the Connecticut Code for similar control. II. IMPORTANT COURT DECISIONS CONSTRUING COMPENSATION STATUTES During the past year there have been many interesting Court decisions relating to the legal liability of an employer for health injuries sustained by employees in the course of employment. Some of these decisions have construed the Workmen's Compensation Acts to cover what appear to be occupational disease injuries under the theory that such injuries arc acci dents; others construe general coverage occupational disease compensation statutes as purporting to provide compensation for many of the human ills to which we may all be subject, unrelated to our employment or the indus trial processes in which we may be engaged; while others relate to the estab lishment of the date from which the period of limitations runs for the filing of claims for oc^upcti-aa; disease injuries under the comnenr.:t:cr. riatutes. In the time given to me it is impossible to discuss many cf these decis ions or to discuss even a few of them in detail; however, I believe they are so indicative of judicial trends in construing an employer's liability for such injuries, that I would like to call your attention to those that to me seem most important. The case of Neill McRae v. Unemployment Compensation Commission of North Carolina. (19-10). 9 S. E. (2d) 595, was a workmen's compensation i ! The followJii>r nd-s and regulations were jppr.v--d at the hearing November 25 to apply l-ot'i to the State- and City: Regulation 1. General. Ni* prs*>tt, firm. corporation or other employer s-hall 1 use or permit to be used in the conduct of his business, miinufat-turing establish ment or other plare of employment, any prows*. material or method of working known to haw an adverse effect on health, unless arrangements have Wen made to maintain the occupational environment in such a manner that injury to health shall not result.' Regulation 2. Threshold limits. Exposure* to dusts, ftnnes. mists, vapors, gases, or arty material* that may affect health shall be kept below the foil*-wing concentration limits. a determined by accepted procedure: Material Concentrations l Pension* (Honzol) ________ 75 parts per million Carbon Tetrachloride ........ I(' parts per million Carbon Monoxide ........ 100 parts per million Chlorine ............ ....................... l-part per million Chromic Acid ................ h.l mg. per cubic meter Kormaldehvde ....................... 2'1 parts per million Gasoline ....................._............ 10(W parts per million Hydrogen Cyanide -............ parts per million Hydrogen Chloride -........ lfl part* per million Hvdrogen Klnoride ..S parts per million Hydrogen Sulfide ______ 2* parts per million Lead .................................. 0.1." mrs. per cubic meter X Methanol ..........-___ l*'h parts per million Nitrogen Oxides .................. 1C parts per million r, Phosgene ..........-............... ..... I part per million Sulfur Dioxide ________ 10 parts per million This regulation, ns it whites to Chromic Acid, shall be construed to apply only to that branch of industry concerned with Chromium plating. Exposure to other materials not Included in the above shall be kepi below injurious concentration*. Dusts of minimi.si. :<t composition and organic dusts shall not exceed concen tration limit* which shall be stipulated. de)H-n<Iing on the nature of the dust. 40 ; 01x59 j.r li . . -- A.W.II TV BiV claim for tuberculosis alleged to have been contracted as the result of work ing with a fellow employee suffering from this disease. The claimant was employed bv the State Unemployment Compensation Commission, and evi dence was offered to show that its olliccs were crowded and tiiat, during February, lli.'JU, the claimant, with a fellow employee named Tyson, were placed across from each other at a very narrow table to do their work; that on or about February 15, 1030, Tyson, who was suffering from active pulmon ary tuberculosis, coughed into the face of the claimant on several occasions; that, thereafter, the claimant, who had previously been strong and healthy, commenced to suffer bodily fatigue and general debility; anu that, on June 5, 1939, upon physical examination, his case was diagnosed as being pulmon ary tuberculosis. An award in favor of the claimant was made by the Com mission on the theory that the injury so sustained was an accident within the meaning of the North Carolina Workmen's Compensation Act. Upon appeal, the Court sustained the award, holding that the tubercu losis suffered by the claimant was directly attributable to his infection when his fellow employee involuntarily and unexpectedly coughed into the claim ant's face, such coughing being "untoward, unfortunate and unusual in it* proximity to and it* effect upon the plaintiff," thus constituting an accident within the meaning of the compensation statute. The case of Vogt v. Ford .Motor Cr>., St. Louis Ct. of App., (April 2,19-10), 13S S. W. (2d) 634, was an appeal from a decision of the lower court, affirming an award of the Workmen's Compensation Commission in favor of the claimant, Vogt, who had applied for compensation for injuries, holding that his contraction of bronchial asthma, allegedly due to cold air, dust and paint fumes, to which he was exposed during the course of his employment, was an accident compensable under the Missouri Compensation Law. The evidence showed that the plaintiff worked in the "trim room" where he assembled parts 2nd put them upon cars as they passed along a 1 conveyor lino. He was stationed near an open door leading into a paint spraying room from which a fan blew paint spraying fumes through the door. Medical testimony was offered that the claimant had allergic bron chial asthma; that the working conditions to which he was subjected had caused this asthma. The Court affirmed the opinion, finding that there was sufficient evidence to justify the Commission's finding that the claimant's condition was the result of his employment. It was further held that, since the claimant's condition was due to an allergy, it was not an occupational disease, since "asthma is not a disease, which from the common experience of humanity, is known to result to others engaged in the same work; in other words, the disease is not a general concomitant or the result of the work which he was doing" and was not a disease known to bo incidental to that particular em ployment. However, the Court found that the injury sustained was an acci dent because it was "an unexpected and unforeseen event happening sud denly and violently with or without human fault and producing at the same time objective symptoms of an injury" found in the act. It was further found that the claimant could not have expected or foreseen that in his phys ical make-up there was a dormant allergy to the particular dust and fumes of his employment. The case of Wolfe v. Brohman (Sept. 18, 3940), Supr. Ct. App. Div., 22 K. Y. S. (2d) 403, was an appeal from an award of disability compensa tion and death benefits in favor of the widow and minor child of the deceased 47 0 51 r y. Tw f employee, made by the State Industrial Board under the Workmen's Com pensation J.av. The deceased employee was engaged as a butcher and meat cutter, which occupation* required him to go in and out of a refrigerator cooler, thereby subjecting himself to sharp variations in temperature. On March 20, 1937, he was compelled to remain in the cooler longer than usual and longer than ho had ever remained on any previous occasion. While in the cooler he suffered a severe chill and was sent home and a doctor called. Pneumonia developed, from which he died. The State Industrial Board found that this pneumonia was the result of an accident and was also an occupational disease, which opinion was affirmed by the Court. There are several cases wherein appellate courts construe occupational disease acts, which are of particular interest. The case of Blassingame v. Southern Asbestos Co., et al. X. C. Supreme Court (March 6, 1940), 7 S. E. (2d) 478, was an appeal to the Xorth Carolina Supreme Court from r.n opinion of the Superior CouTt, running an award by the Workmen's Compensation Commission in a claim for death from lobar pneumonia, allegedly due to asbestosis. The claimant's decedent had worked for the defendant for a period of seven years, and died on April 1, 1937, a few days after having driven to the State of Georgia for a vacation, and suffering with a heavy cold at the time of his trip. An autopsy was performed on May 10, 1037, and medical evidence was ottered showing lie was affected with the early stages of asbestosis. Notice and claim were made out July 19 and filed on July 20, 1937. The claim was referred to the mem bers of the Advisory Medical Committee under the North Carolina Compen sation statute, whose testimony estsiblished that asbestosis was not a factor in causing the decedent's death. The case was first heard before one mem ber of the Commission, who denied compensation. The full Commission then reversed the decision of the individual Commissioner, finding, as a fact, that decedent's asbestosis lowered his resistance to the pneumonia. This decision was affirmed by the Superior Court and later affirmed by a four-three deci sion of the Supreme Court of North Carolina. The two phases of this case that are of particular interest to this dis cussion are as follows: J. The findings of the full Commission reversed the decision of the individual Commissioner to the effect that the decedent's asbes tosis was a contributing cause of death, because of his lowered resistance to pneumonia, even though the Advisory Medical Committee had testified that the decedent's asbestosis had played no part in his death. Therefore, the majority members of the Compensation Commission, in fact, overruled the medi cal findings of the Advisory Medical Committee. 2. The North Carolina Occupational Disease Act, Sec. 0O-I2 (o), provides: "Unless written notice of the first distinct manifestation of an occupational disease shall be given to the employer .... or to the Industrial Commission within thirty (30) days after such manifestation, and, in case of death, unless also written notice of such'death shall be given to the beneficiary hereunder to the employer or the Industrial Commission within ninety 4S (90) days after occurrence. . . ." the right to compensation for disability or death shall be barred. In this ease it will be noted that death occurred on April 1; that the autopsy was performed on May loth, and that notice and. claim were not made until July 19th. The Court found that the notice given was timely, on the theory that notice of death had been given within ninety days after the widow dis covered her husband was suffering from asbestosis, even though the statute established that such notice should be given within ninety days after death. The majority opinion based its con clusion on the ground that the want of notice did not prejudice the employer. The case of Moffett v. IJarbtsou-Walker Refractories Co., 14 Atl. (2d) 111, decided June 14, 1910, by the Supreme Court of Pennsylvania, was an appeal from an order sustaining a statutory demurrer to plaintiff's state ment of claim in a common law action against his employer for alleged par tial disability from silicosis. The Pennsylvania Occupational Disease Com pensation statute denies compensation for partial disability, and yl. ' 'tiff's declaration alleged such partial disability sustained while in the defendant's employ. The plaintiff contended that, since the injuries sustained by him were not compensable under the occupational disease compensation act, he retained his right of action for such injuries at common law. In denying the right to the plaintiff' to maintain his action the Court said: "It is common knowledge that in the early stages silicosis is difficult to detect. A Commission on Compensation for Occu pational Diseases which reported to the Governor in 1933 recog nized that silicosis and miner's asthma, because of their slow development, presented the `greatest difficulties as administra tive problems.' The Legislature recognized the difficulty of the subject and provided, in relief of the possible burdens on the employer, that the Commonwealth would contribute $100,000 for the purposes specified in Section 7. It also provided, in the circumstances stated in Section 10, for the appointment of a Medical Advisory Board to report to the com pensation authorities on silicosis cases on trial, and in Section 11 .for the `entry of any physician, surgeon, or expert upon the premises of the defendant employer in order to ascertain the facts in any case arising under this act.' We think it is clear, therefore, that the legislature intended to bring all silicosis sufferers, whether partially or totally disabled, under the Act and that by accepting the provisions of the compensation acts, an employee agreed to look solely to the Act for compensation and to give up any remedy he might otherwise have had." In the case of Peter Tomsic v. II. C. Frick Coke Co^ decided by the Workmen's Compensation Board of Pennsylvania on September 6, 1940, the claimant filed a petition on January 17, 1939, alleging total disability resulting from silicosis or nmhraco-silicoMs, which he contracted during his employment with the defendant. The claimant offered medical testimony that he was suffering from chronic bronchitis, better known as "miner's asthma," and admitted that he was not suffering from silicosis or asbestosis. The Act of July 2, 1937 (P. L. 2714, Sec. 2), which was the Occupational Disease Compensation Act effective during the time of the claimant's em- 49 ploynient, did not provide compensation for miner's asthma. That act was amended by the Act of June 21. 1939, the amendment .defining: compensable occupational diseases to include "silicosis or anthraco-silicosis (commonly known as miner's asthma and hereinafter referred to as anthraco-silicosis)." The Board held that since this act did not take effect until October 1, 103'J, it was not retroactive and that, therefore, the employer was not liable for the compensation sought in this case. I would like also to call to your attention two decisions of the Missouri Appellate Courts, establishing the time from which limitations run for the filing of occupational disease claims under the Compensation Statute. In the case of Cleveland v. Laclede Christy Clay Products Company, 129 S. tV. (2d) 12, claim for silicosis injuries was made. The claimant operated a truing machine for the purpose of grinding and finishing tile, lie was first employed in 192$ and in 1933 began to develop symptoms of chest pathology. He was attended by a physician on January 30, 1933. and advised to discontinue work. He laid off for a period of five weeks during which time roentgen examinations were made of-his chest. At the end of five weeks lie returned to work, but his condition became g--J'i-.lly worse and he discontinued work on June 22. 1936. He was again examined on January V, 1937, and advised by his doctor on that date that he had siiicosis, this being the first time that he was told the name of the disease from which he was suffering. Claim was filed on January 2$, 1937. The Compensation Commission awarded compensation, which award was reversed by the lower Court, the reversal being sustained by the Court on appeal, because the claim had not been filed within the six months period required by the statute. In passing upon this point, the Court said: "According to his own testimony, claimant knew more than six months prior to the filing of his claim, that he had this trouble in his chest, and that he had been treated for it. He knew that the chest trouble was the cause of his inability to do his full work and that the nature of the work aggravated this condition." The Court further said: "This section (Section 3337) has been construed as a limita. tion on, and an extinguishment of the right itself to maintain the action when not exercised before the six-mor.ths period of limitation has run against it. It seems to be the well settled rule in rc-spect to latent injuries'that-the six-months limitation for filing claim for compensation commences to run from the time it becomes reasonably apparent and discoverable that the employee has sustained a compensable injury." The case of Renfro v. Pittsburgh Plate Glass Company, 130 S. IV. (2d) 165, indicates the attitude of the courts with respect to a construction of the six-months limitation period in a manner as favorable to the claimant as possible in order to protect his claim. That case involved a claim for sili cosis, the claim having been filed September 1, 1937, alleging that disability began January 4, 1937. The Commission found, as a matter of fact, that disability began January 4, 1937. On March 11, 1937, the employer and employee had entered into an agreement providing for voluntary payments to the employee, such payments, however, not to be construed as an ndmis- 50 sion of liability on the part c*f the employer for compensation. Payment? wove made to the employee under this agreement until December 12, 1937. In passing upon the question of limitations, the Court said: *'Jf we were to adopt the employee's view in the case at bar, that tho Commission's award as for an injury in December, 1935, is correct, although there was no disability or loss of earn ing power until January, 1037, then a proper regard for the law would require us to hold that the employee's claim herein is barred by the six-months statute of limitations, because his claim was not filed until September 1, 1937. It is extremely important that we should not adopt a rule which would result in claims of employees being barred by the Statute of Limita tions under such circumstances as appear in this case. We arc of the opinion that the statute of limitations is not involved at all under the evidence herein because we are bolding that the Commission's award of compensation, based on an injury as of December, 1935, is incorrect. Such award as for permanent total disability contradicts the Commission's own findings of fact that t'nero was no disability until January 4, 1937, ur*H ?<s not supported by the evidence. Furthermore, the evidence shows that the employee's claim was filed `well within six months from the date of last pavmc-nt' as provided bv Section 3337 R. S. Mo. 1929." CONCLUSION It is apparent that the trend of judicial opinion is toward a liberal interpretation of our compensation statutes, in providing compensation for those injuries to health that are peculiar to the employment, and may be aggravated by conditions of the employment. It is also apparent that in those Stales having general coverage occupational disease compensation laws, compensation will be awarded for health impairment that is common to every-day life, provided there is medical testimony in the case expressing the opinion that the injuries so sustained may have been caused or aggra vated by the conditions of employment. If this tendency continues substan tial unanticipated expense will be imposed upon employers and their insur ance carriers because of awards for tuberculosis, pneumonia, asthma, and other similar respiratory diseases. During the State legislative sessions of 1941, we will find, undoubtedly, that many bills relating to this subject will be introduced and pressed for enactment, proposing to liberalize benefits and .broaden the scope of com pensation coverage. These developments emphasize the fact that it has become and will continue to bo good business for industry to concern itself with the protec tion of the health of industrial workers and, in giving consideration to the legal responsibility that arises from injuries to that health, we come to the full appreciation of the importance of comprehensive programs for industrial hygiene. 51 c x0 STATE INDUSTRIAL HYGIENE UNITS STATE AND EXECUTIVE ALABAMA Dr. John R. Cain, Director, Division of Industrial Hygiene, Department of Public Health, Montgomery, Alabama.' CALIFORNIA Dr. J. I*. Russell, Chief, Industrial Hygiene Service, Department of Public Health, 2002 Acton St., Berkeley, California. Dr, V. A. Nasatir, City Health Department, Los Angeles, California. COLORADO Robert J. Owens, Industrial Hygienist, Division of Industrial Hygiene, Colorado State Board of Health, State Office Building, Denver, Colorado. CONNECTICUT Dr. A. S. Gray, Director, Bureau of Occupational Diseases, Connecticut Department of Health, Hartford, Connecticut. IDAHO Dr. E. L. Berry, Director, Division of Public Health, Boise, Idaho. ILLINOIS Dr. M. H. Kronenherg. Chief, Division of Industrial Hygiene, Department of Public Health, 1800 Fillmore St., Chicago, Illinois. **' ** INDIANA Dr. Louis W. Spolyar, Director, Bureau Industrial Hygiene, Indiana State Board of Health, Indianapolis, Indiana. IOWA P. J. Houser, Industrial Hygiene Engineer, C. L. Campbell. Chemical Engineer, Department of Health, Division of Public Health Engineering and Industrial Hygiene, Des Moines, Iowa. 52 REMARKS STATE AND EXECUTIVE REMARKS KANSAS Dr. Krnti-t Boyce, Engineer & Director, Division of Sanitation, State Board of Health, Marvin ilaii, University of Kansas, t Lawrence, Kansas. MARYLAND 4# Dr. John >1. McDonald (Medical Department), City of Director, , Baltimore only Bureau of Occupational Diseases. Dr. Wilmer II. Schulze, Director, Sanitary Section, Baltimore City Health Department, Baltimore, Maryland. MASSACHUSETTS Manfred Bowditch, Director, Conducted in a cooper Bureau of Occupational Hygiene, ative, joint approach to Department of Labor and Industry, problem by labor and Boston, Massachusetts. health departments MICHIGAN Dr. Kenneth E. Markuson, Director, ' Bureau of Industrial Hygiene, Department of Health, 1151 Taylor Avenue, Detroit, Michigan. MINNESOTA Dr. A. J. Chesley. Executive Department of Health, 469 State Office Building, St. Paul, Minnesota Officer, Service available after January 1, 1941 MISSISSIPPI Dr. J. \\\ Dugger, Director, Date service will be I Industrial Hygiene & Factory Inspection, available not yet an- State Board of Health, nounced Jackson, Mississippi. MISSOURI Dr. Hafry F. Parker, State Commissioner, State Board of Health, Division of Engineering, Jefferson, Missouri. Health MONTANA Dr. Lloyd M. Farner, Director, < Division of Industrial Hygiene, State Board of Health, t Helena, Montana. \ i NEW HAMPSHIRE Frederick J. Vintinner. Industrial Hygienist, Industrial Hygiene Unit, State Board of Health, 'i'- Concord, New Hampshire. 53 0 W i W:-V.W !.W W W -nii. h STATE AND EXECUTIVE NEW YORK Dr. Leonard Orienl>urg, Executive Division of Industrial Hygiene, Department of Labor, 80 Centre Street, New York, New York. Director, NORTH CAROLINA Industrial Commissioner, Nortii Carolina Industrial Commission, Raleigh, North Carolina, OHIO Dr. Ji B. Kistler, Chief, Adult Hjgiene Division, Ohio Department of Public Columbus, Ohio. Health, OKLAHOMA Dr. G. F. Mathews, Commissioner of Health, H. J. Darcev, Chief Engineer, Director, Bureau of Sanitation, State Health Department, Oklahoma City, Oklahoma. PENNSYLVANIA Dr. John J. Shaw. Secretary of Health, Department of Health, Commonwealth of Pennsylvania, Harrisburg. Pennsylvania. RHODE ISLAND Charles L. Pool, Chief of Division, Division of Sanitary Engineering, 'Department of Health, State Office Building, Providence, Rhode Island. SOUTH CAROLINA Dr. Harry F. Wilson, Director, Division of Industrial Hygiene, State Board of Health, Columbia, South Carolina. TENNESSEE W. C. Williams. Commissioner. Department of Public Health, State of Tennessee, Nashville, Tennessee. TEXAS Dr. C. A. Nau. Director, Division of Industrial Hygiene, State Department of Health, Austin, Texas. 54 REMARKS Even though the Division of Industrial Hygicne is a department of state health depart ment, Industrial Com mission allocates cer tain funds to it. y Ai.i iiLoOil STATE AND EXECUTIVE UTAH J. L. Jones. M. n,, I). V. H.t Director. Industrial Hygiene, State Board of Health, Salt Lake City, Utah. VERMONT Harold W. Slocum, Director, Tuberculosis Divioion of Industrial Department of Health, 348 College Street, Burlington, Vermont. Hygiene, VIRGINIA It. T. Homewood, Engineer, Bureau of Industrial Hygiene, Department o Health, Richmond, Virginia. WEST VIRGINIA Dr. Arthur E. McClure. State Health Commissioner, Department of Health, Charleston, West Virginia. WISCONSIN Dr. P. A. Brelim, Supervisor, Division of Industrial Hygiene, State Board of Health, Madison, Wisconsin. REMARKS The following City Health Departments also have industrial hygiene divisions: Flint, Grand Rapids, Newark, Saginaw and St. Louis County. DR. MELLER: Thank you very much, Mr. Dorsett. Is there any dis cussion? We go then to the Symposium on Industrial Health Defense. Professor Drinker will preside. ^ PROFESSOR DP.INKER: Regardless of our jobs or our political affili ations, the general topic of this symposium is one of enormous interest to us. We have the advantage of having with us, as participants in this sympos ium, several men whom we have never had the pleasure of hearing at these meetings and some of whom have not attended the meetings at all before. The first speaker, Dr. Neal, who is no longer acting chief but chief of the division of industrial hygiene, is the successor of our very good friend and ardent supporter. Dr. Sayers. It is especially pleasant for us to have him here with us today. His subject and the activities of the Public Health Sendee in the national defense program are perhaps one of the chief guiding points for those of us whose professions He in industrial hygiene. We look to them constantly for advice and for direction. It is especially pleasant for us to have the chief of the division with us today. 55 o 0 f -J activities or TJiK public health service IN THE DEFENSE PROGRAM PAUL A. NEAL, M. D.* One of the outstanding developments of the present national defense pro gram has been the recognition on the part of the leaders of our Nation that health is an essential element of preparedness. On September 15, 15-iO, the President approved an order establishing a Health and Medical Committee to advise the Council on National Defense, and to coordinate medical and health activities affecting national defense. This Committee consists of the following members: Dr. Irvin Abel!, Chairman; the Surgeon General of the Army; the Surgeon General of the Navy; the Surgeon General of the Public Health Service; and the Chairman of the Division of Medical Sciences of the National .Research Council. This Committee and its many sub-committees have the responsibility of advising the Council on National Defense regard ing the health and medical aspects of national defense, and of coordinating health and medical activities affecting national defense. One of th.. import ant subcommittees set up by the Health and Medical Committee of the Council on National Defense is the one on industrial medicine. Inasmuch as the program for national defense has already served to emphasize many problems pertaining to the public health, the Surgeon General of the Public Health Service, Dr. Thomas Parran, catled a special conference of the State-and Territorial Officers on September 1C and 17, for the purpose of reviewing plans and agreeing on a program of action. Dr. Parran enunciated the keynote of the conference in the introductory para graph of his address. He said: "The most impelling problem which we face today is that of maintaining the safety of this country and its institutions. For their aggressive defense, wc are gearing up governmental methods, mobilizing resources and manpower. For the first time in ail his tory, world events have thrust upon us the concept of a total war. t In preparing a total defense, all factors ultimately rest upon the } one fundamental resource of the country, manpower. Medicine and i public health, through the centuries, have been devoted to the con i servation of manpower and its socially constructive use." ] In any discussion of methods planned for effectively carrying out a pro gram it is essential that the problem to be solved be definitely outlined. The various health problems confronting the Nation-as a result of the present emergency were clearly defined at the Conference of State and Territorial Health Officers meeting with the Surgeon General last September in Wash ington. These may be briefly summarized as follows: Rehabilitation EMERGENCY HEALTH PROBLEMS One of the pressing problems we are faced with is the physical rehabili tation of registrants disqualified for duty with the armed forces. Based on the experience of the last World War, we may expect approximately 25 per cent of those examined to be rejected, with about 55 per cent examined hav ing one or move defects. Of the 17,000,000 registrants, probably 0,000,000 Chief. Division of Industrial Hygiene, National Institute of Health. 56 A/: will he examinee!. Hence, we may expect approximately 1,500,000 persons to bo rejected, or placed on limited-service, because of physical disability. We may also expect that GO per cent of the disabilities will he due to such fac tors as eye and ear defects, mechanical defects, and heart and kidney condi tions. Tor example, it is estimated that 140,000 men will bo rejected because of tuberculosis. It is evident that the problem of rehabilitating such large numbers is of paramount importance at this time, especially when we realize the fact that many of these individuals not lit for military service will find their way into industry. A plan for the correction of those defects which arc remediable will serve to improve the health of our manpower, thereby also increasing the efficiency and productive capacity of this man power. Civil Defense The health aspects of civilian defense are primarily a responsibility of the communities and their respective local governments. Among some of the problems which need to be dealt with by civil authorities are emergency police measures, fire protection, safeguards for public utilities, transporta tion, and provisions of health and medical services in the 0f disaster. There is also the problem of protection of local residents against gas attacks, air raids, and the evacuation of refugees. The effectiveness of the entire effort of civilian defense will depend upon the thoroughness of organization, training, and discipline of the local residents. Communicable Diseases Another topic which was thoroughly discussed at the Surgeon General's conference was the control of selected communicable diseases. Army and Navy personnel attending the meeting disclosed their plans for immunizing the newly inducted men against smallpox, typhoid and tetanus. It was shown that not a single case of tetanus was reported among men of the French army who received the liquid tetanus toxoid. The problem of meas les and mumps among young men in the Army was discussed, and plans for the control of malaria in some of the southern training centers were pre sented. Assurance was given that there is at present a sufficient supply of serums and drugs for meeting our requirements. Health Administration One of the most important problems confronting public health and mili tary authorities arises from the mobilization of armed forces and industry. Some of these problems will be due to rapidly expanding industrial centers as well as in zones surrounding cantonments and maneuver areas. These rapid increases in population are already taxing the milk supply, the water supply, and the sewage disposal systems of the communities involved. Hous ing has already become a serious problem in such communities. It is a wellknown fact that the health of civilians in a community surrounding a can tonment will have an influence on the health of those in the camps. This is particularly true of such diseases as syphilis. All of these problems will be a responsibility of official local health agencies, but funds and personnel from the States and the Federal Government will be needed. In this connection the Conference of State and Territorial Health Officers at its last meeting included among its various recommendations the follow ing: "That the U. S. Public Health Service be urged to secure the necessary funds to reinforce existing State and local facilities for the efficient and expeditious inauguration and operation of those emergency health activities 57 i i / i i & in military and industrial mobilization areas." The Conference further urged the coordination of activities pertaining to industrial hygiene and stres>cd the necessity for supplementing the efforts of the States. Industrial Hygiene It is now a well established fact that military mobilization and expan sion is impossible without industrial mobilisation and expansion. The present industrial expansion has already brought in its wake many now problems in employee health. To insure maximum physical fitness, the industrial worker needs to develop a high sense of personal responsibility. Industry must continue and accelerate its efforts to protect and promote physical welfare among workers, and the various health agencies, both gov ernmental and private, must give every (possible assistance through scientific research, through the expansion of community sanitation measures, and through the application of our developments in both the prevention and treatment of disease. Despite continued progress in the field of industrial hygiene, we still have in this country 17,000 occupational-deaths from acci dents every year; 75.000 permanent disabilities; and 1,400,000 tempever,. dis abilities. Recent surveys conducted in industry show that the working en vironment of about 1,000,000 persons requires investigation by trained indus trial hygienists to determine whether or not the presence of silica dust in the air constitutes a health hazard. The conditions of work of 800,000 persons handling lead and its compounds also need study. Similar information is available on many other potentially hazardous exposures. For example, it is well known that many millions of workers are exposed to materials which, if improperly used, are capable of causing skin diseases. Furthermore, it is well known that industrial workers have higher rates of physical defects than non-industrial workers and that the death rate from all causes among unskilled workers is 100 per cent or more in' excess of the death rate among agricultural employees. The many studies of illness among workers recently completed show that the average worker in this country loses 10 days a year on account of sickness. In fact, general illnesses have been found to account for 15 times as much time lost as that due to both accidents and occupational diseases. This problem of lost time from disability among workers is of vital importance now that our industrial machine is playing such a prominent role in the defense effort. Our recent studies have also shown clearly that although industry is cognizant of the problem and is making progress, much still remains to be done. For example, only 25 per cent of our workers have full time safety direction sendees, only 15 per cent have full time medical services, and only 33 per cent have nursing services. Engineering studies have also brought out the fact that protection against exposures to hazardous materials and conditions is still far from adequate. The present industrial activity on defense orders has already augmented these problems in industrial hygiene. Able-bodied men are being mobilized into our armed forces and these will have to be replaced in industry by older men, by young adults and, in some eases, by women. Many of these newly inducted industrial workers will not be as physically fit for arduous tasks, nor wili they be as skilled. The problem of fatigue, so important in the first "World War, will again reappear as the result of the rapid tempo of indus trial production. Many hazardous chemicals, both old and new, will be intro duced into irdustry. We may expect crowding in factories and we must fight the tendency to relax in the vigilance so necessary to prevent accidents 58 0 J. J. 6 3 " ' 1111 1 ~ TV,.--**,--t-- rrll,Vnrtifr, and diseases among workers. Dr. Parran has stated that our industrial machines are rated to be the most efficient in the world, and he rightfully insists that the men and women who operate these machines should have a comparable efficiency. Those, in brief, are some of the problems facing us today in our health preparedness program. The Committee on Health and Medical Preparedness recently established by the President, and its many subcommittees, are already coping with thee various problems confronting us. The work of coordinating existing machinery both as to public health and medical facili ties is under way. Insofar as industrial hygiene is concerned, the ground work laid by research during the past quarter century and the machinery developed during the past several years for the application of this research by the States and by industry finds us better prepared to cope with indus trial health problems than at any time in our industrial history. We know that every job can be done safely if we only apply our present knowledge. THE PROGRAM With reference to those activities on health and medical preparedness concerned with the civilian population and our armed forces while in nam ing, the Public Health Service is working very closely with the Army, the Navy, and the Stale and local health departments. The Surgeon General of the Public Health Service has already appointed medical and engineering liaison officers to each of the Army corps areas, for the purpose of expediting the solution of the various problems discussed herein. Reconnaissance sur veys are even now being made by the Public Health Service and State health department personnel in the various areas to determine the exact needs in each locality. Fortunately, the industrial hygiene program could be launched immedi ately, in view of the fact that the various States in organizing their indus trial hygiene services had already made detailed surveys of the problems in each locality. The States are therefore in a position to know where these sendees are needed. Furthermore, many of the research activities of the Divi sion of Industrial Hygiene, which are carried out during peace time, furnish us with the key to the solution of problems of a military nature and some of our findings can .also be applied to emergency problems in industry. For example, the study this Division recently completed on the fatigue status of truck drivers has furnished us with a great deal of information applicable to fatigue problems which may arise in industry as a result of increased activities. The industrial medicine subcommittee established by the Health and Medical Committee of the Council on National Defense has already been assured the fullest cooperation of the Industrial Hygiene Division of the National Institute of Health. All of the facilities of this Division will be put at the disposal of the committee, and a greatly expanded employee health program is being developed in close collaboration with the 31 State indus trial hygiene units, with industry, labor, and numerous official and unofficial agencies. In other words, a program has been developed for coordinating the work of all the Federal and local agencies, of industry, of labor, of the medical and engineering professions, and of all organizations vitally con cerned with industrial health. Insofar as the Division of Industrial Hygiene of the National Institute of Health is concerned, its functions may be considered as partly adminis- 59 C trative, concerned with coordinating all activities both at the Federal and State level, a ml mostly concerned with the promotion of industrial hygiene services in State and local health departments, and with scientific investiga tions conducted both at its laboratories and in the field. The Division of Industrial Hygiene is already carrying out urgent research directly related with defense and it is working very closely with both the Army ami the Navy. In addition to fundamental laboratory research on toxic materials of direct importance to national defense, some of the Division personnel are being employed to supplement the work of those States which have been con fronted with emergency problems too great for successful handling by their own efforts. If tiie necessary funds for this phase of the work are obtained, it is planned to have at least 15 units in the field, each consisting of a trained physician, an engineer and technical support, for the purpose of assisting the State industrial hygiene units on emergency problems. Several such units are already doing work with the States. In brief, the work which the Industrial Hygiene-Division is already per forming, and which it hopes to expand, may be summarized as follows: 1. Industrial hygiene services to Government.'.a&fenals and other Federal project-'-. 2. Assistance to the States on industrial hygiene problems in defense industries. 3. Toxicological research on defense materials. 4. An appraisal of the fatigue status in relationship to the national defense program. 5. The determination of methods for the absorption of handi capped persons into vital industries for national defense. 0. The preparation and dissemination of information on various toxic materials and processes, including approved designs of exhaust systems for the control and elimination of atmospheric contaminants. Practically all of the States having industrial hygiene divisions have already submitted programs to the Public Health Service for assisting indus try in maintaining healthful working conditions and healthy workers. These programs differ in no way from those already practiced by the States in the past, except that emphasis will be given to directing their efforts to indus tries engaged on defense contracts. In other words, the work in the States will embrace the following activities: 1. The evaluation and control of the various health hazards aris ing from exposure to dusts, fumes, ga$es,,and vapors. 2. Advice to industry in the construction of new plants and in the renovation of old plants in the interest of safety and health. 8. The promotion of physical examinations and medical services to workers by industry. 4. The promotion of measures for the control of communicable disease, such as syphilis, pneumonia, tuberculosis, and others. 5. The preparation and dissemination of information on various toxic materials and processes, including approved designs of exhaust systems for the control and elimination of atmospheric contaminants. Industry is thoroughly convinced of the fact that it pays to control acci dents. In reducing the frequency, severity and monetary losses involved in 60 industrial accidents industry attacked the problem from two viewpoints: First, by the provision of well guarded equipment, and second, by the educa tion of workers in safety measures and practices. We arc thoroughly con vinced that the same tactic* will materially aid in reducing lost time from occupational diseases and other illnesses. In other words, first, wc must pro vide a safe and healthful environment, and second, wc must educate the worker in safe practices and healthful living. It is quite evident that insofar as public health and medical prepared ness are concerned, plans have been created which are not emergency impro visations, but are designed to be an integral part of our national life in the future. This is especially true of our industrial hygiene program, and it is hoped that we will not forfeit the gains wc have made so for for the sake of expediency. All of us, be we public health workers, private medical practi tioners, engineers, chemists, industrial managers, or factory workers, must assume leadership and responsibility and coordinate all of our efforts, so that the men and women in our industries will attain a high level of efficiency and health. PROCESSOR DRINKER: I am sure that Dr. Neal will be glad to answer questions as to the matters which he has brought out. MR. CONNOR: I should like to ask the speaker whether or not he can tell me this. I have about sixty young men of draft age who arc receiving regular routine treatments for syphilis. They are continually asking me if when they are called the government will continue their treatments in active service or whether they will be rejected. 1 can't tell them. I'd like to have some help. DR. NEAL: I can't speak for the Army, naturally, on that. My opinion would be, and I think it is the present thought, that each individual case is decided on its own merits in connection with this communicable disease, as others. If the men are not disabled, and we assume these arc not--in other words, they don't have cardiovascular disease---they will receive the same treatment they are getting now after they are inducted into the service. Whether they will be inducted into the service or not I don't know. I think it will be decided on each individual case. PROFESSOR DRINKER: Dr. Sayers, I think we should all be glad to hear a word from you. DR. SAVERS: I am very much interested, as you know, in the program that has been outlined by Dr. Neal for you and to vou. It is one that has .been developing for a matter of years. There are many of you sitting around here who have been associated with us in the development of that program. Most of you in the room have had something to do with it. The program is not new and it is not a program that is just for defense alone. As in all industry, as in all the work that we arc going to do, it must be speeded up if it is going to accomplish the purpose we are to have. In answer to the question, if I may expand a little on Dr. Neal's state ment, I think that whether any individual who comes up is inducted or not will be determined by your local draft board to a great extent. I don't think we need to worry very much about those people with syphilis. They will receive treatment. They will no longer be communicable from one to another in the army. I don't think we need worry too much about it. I do think that we all have a real problem in regard to industrial 61 ***** hygiene. I think we ail must get behind it and push it. We cannot succeed in this war unless we have our workers in good health. Whenever a man is away, it doesn't make any difference whether it is occupational disease, accident, or just illness that causes him to be away, it interferes with pro duction, and production is important to us' today, it is a very serious thing. Again, we are not here to scare anybody. We just want to work along efficiently, ami scared people are not efficient. Wo have a job in front of us, and it is a big job. Wo must all work. I hope we can support all the group. There are several here on this medical defense who belong to the Advis ory Committee, I believe, of the Medical Defense Commission--or is it the Defense Council? You know the Defense Council is made up of secretaries in our cabinet. There is an Advisory Commission to the Defense Council. Then they have special committees .in the Research Council that advise them, and the Medical Committee is one of that organization, as I understand the J i present group. . Then there is a sub-committee on Industrial hygiene. The program is being worked out, I believe, expeditiously. We cannot work h: fast. The groundwork has hen laid the period of years that has gone by and part of that groundwork is within this organi zation here. Dr. Neal has emphasized to you the importance of cooperation and coordination. That must be had if it is to be efficient. It is a great pleasure for me to be here with you today. I thank you all. PROFESSOR DRINKER: If there are no further questions we will proceed with the next paper. Thank you very much. Dr. Neal. Our role as a nation in this present emergency, whether we are helping the Allies or whether we are simply helping ourselves, is distinctly up to the present time one of production--production of armaments. It has been said by those in position to know that there is probably no single operation that is more important to the production program than welding, both electric welding and gas welding. Dr. McCord, with his colleagues, for some time has been engaged in the study of the health aspects of arc welding. The first paper that they have published on this subject appeared recently, in the Journal of Industrial Hygiene. Perhaps some of you have had the oppor tunity to read the paper. It is particularly pleasant for us, therefore, in the Foundation, to have had Dr. McCord accede to our request that he come and talk to us today on his own work. I have much pleasure in introducing to you Dr. Carey P. McCord, Director of the Industrial Health Conservancy Laboratories. THE HEALTH OF ELECTRIC ARC WELDERS IN THE NATIONAL DEFENSE PROGRAM GORDON C. IIAIIROLD, Ph. l).,c STUART F. MEEK, .M. V.t" and CARET P. McCORD, M. D.f Introduction Arc welding in itself cannot defend a country or win a war, but neither of these national enterprises well may be prosecuted without reliance upon ore welding for many essential fabrications. The extent of arc welding in this country may be gauged by live fact that in 1939 152,863,-10') pounds of welding electrodes were utilized, with -tt|:ebrrespending figure for the first six months of 19-10 of 6C,044,600 pounds. From another,jource has come the statement that the total production oL.A''ulding rods,';lnclu<ling automatic welding rods, was, for the year 19:19,157030,200 pounds, of which 129,030,211 represented heavily coated carbon steel^ods, with only i0*!o-l,186 pounds of bare washed or dust coated rods. Tlicsfe^gures indicate`that les* S'.c of the country's urc welding is carriedout with bare rods. However, this marked shifting to heavily coated rods is not true for all industries. In one automobile plant, where the greater portion of welding is accomplished by spot or pressure welding, thus calling for no electrodes, more than a minion pounds of bare welding rods were applied in a recent 12 months' period, but of this total poundage of welding rods only 0AKV was represented by coated rods of all varieties. Every modern standard automobile possesses more than 5,100 welded points with, however, only some 140 arc welds, but several of these arc welds are ninny inches long. This year of 1940 sav; the first all-welded ocean-going steamer, the 17,000 ton Exchequer, launched in Mississippi in June. Commercial naval construction technology of this war period in some measure may become symbolized by this first all-welded freighter. The extent of welding, with out at this time specific reference to arc welding, again is reflected by the fact that about 200,000 welders are now employed in the United States. To express this in military terms, these welders represent an army of approxi mately 23 stream-lined divisions or seven army corps. As welding applications increase, more and more the need is for a better understanding of the hygienic exposures that may arise. The world of industrial hygiene is not in a happy position in its knowledge of the nature and extent of exposures for arc welders. Apparently many of us are hampered by too much reliance upon traditional standards, particularly with regard to nitrous gases. Examination of the original publications upon which some of these much advocated standards are based reveals a scantiness of evidence far in disproportion to the significance long attached to them. In facing the actuality of industrial hygienic shortcomings with regard to the exposures connected with arc welding, several things contribute to the obvious complexity of the situation. First, the quantitative determination of some welding gases, such as the several nitrogen oxides and ozone is far more difficult than for many other substances. Second, the coating materials applied to welding rods are so diversified and so rapidly changed as to baffle almost any attempt to keep abreast of developments. Third, alloyed steels, Chrysler Industrial Hygiene Laboratories. 4 industrial Health Conservancy Laboratories. 63 / i il \ i \ 4 3 It: such as nickel-chrome steel, or metals that have Keen coated, such as in gal vanizing, ave introducing new difficulties in connection with welding opera tions. As a result, the attending industrial hygienic situations arc far from simple. In general, the potential sources of injury from arc welding oth-r than from trauma ami thermal effects, seemingly may be grouped in the following categories: Oxygen deficiency. Carbon monoxide. Nitrous gases. Ozone. Metal fume from alloyed steel. Metal fume from the metal electrodes. Silica from welding rod coatings. Harmful substances other than silica in rod epatings. Injurious substances coated on to the metal being welded. Radiations. Possibly other gases such as cyanides theoretically produced in the electric arc. From fairly extensive first hand experimental work and medical depart ment experience with several hundred welders, we have reached a number of conclusions soon to be presented, but unfortunately space does not permit adequate presentation of the evidences upon which these conclusions are based. Before entering upon any further discussion of some arc welding exposures, it is here emphasised that arc welding does not preempt the field of possible injuries related to welding and that gas welding in particular may provide danger? under fortuitous circumstances. Brief Review of Out Recent Experimental Work with Bare Iron Electrodes1 In our welding experiments, welding was carried out for six hours a day, five days a week, in a metal gassing chamber 10x10x10*. In these experiments, the welder was located on the outside of the chamber perform ing welding with arms inserted tlirough portholes. Animals in cages protected against ultraviolet light from welding were exposed for six and one-half hours daily. The exhaust system of this exposure chamber was dampered to less than two changes per hour. The rate of-welding was represented by the maximum number of rods that might be burned in a unit of time. In one experiment with a vukage of 44 and an amperage of 300-000, 48 to 50 bare rods were burned in 24 minutes of every hour, which aggregated approxi mately 19 pounds per welding day. In four major experiments, limited to uneoated welding rods, 250 animals (rabbits and albino rats), including 87 controls, were observed over a period of 20 months with the longest experi ment continuing 9 weeks (45 exposure days). These experiments established that nitrous gases (reported as nitrogen dioxide IXOt0), increased with every increase in voltage across the arc as Utilized. At 27 volts (1S0-200 amp.) the average ppm. were 29; at 31 volts (200-225 amp.), 33 ppm.; at 33 volts (250-275 amp.), 40 ppm.; and 44 volts (300-350 amp.), 70 ppm. While the average concentrations found were as Just indicated, concentrations at times ranged much higher, averaging 97 64 Ur ppm. under some conditions with an extreme maximum of a single sample of 135 ppm. with a duplicate of 127. While suitable tests were made for carbon monoxide, excess carbon dioxide, oxygen deficiency, excessive temperatures, chlorine, etc., chief deter minations made were the quantities of nitrogen dioxide, ozone and metallic fume. Nitrogen dioxide was determined through the nitrate method and samples collected throughout the day, immediately at the cessation of every welding cycle, 4", 10" and 16" thereafter, that is, in every hour there were two welding cycles, each with welding continuing for 12-14" and sample taking from 16-18". Thus, in a single hour, as many as 8 samples for nitro gen dioxide alone at times were collected. In the aggregate, approximately 2,400 determinations were made for welding gases and fumes. The quantity of particulate iron ^present as a-ume:and arising from the arc ranged from 35-305 nigms. per cubic meter The quantity of iron fume constituted no measure of the quantity-of.pilous gases present. Likewise, the quantity of fum across the arc. Ozone (0*) both hr.: b phere about the electric arc. In our experience, from 10-32 ppm. were found within 1" of the arc, from 0.5 to 9 ppm. 4" from the arc and from 0.1 to 1 ppm. in the center of the chamber, all samples being taken during the /lam ing of the arc. Unlike nitrous gases, increase in voltage apparently did not create increased Quantities of ozone. No product of this experimental welding, regardless of voltage or of the prolonged duration of exposure produced any obvious changes characteristic of the action of nitrous gases. With a voltage of 44, the experimental ani mals were exposed for 125 hours to a concentration of 70 ppm. of nitrogen dioxide, including 33 hours in the aggregate at 84 ppm. of nitrogen dioxide and with the exception of a portion of the first hour of every welding day. no exposure to nitrous gases during the 40 days of elapsed time was lower than 46 ppm. In 8ll experiments, the survivors exceeded 90r,i of the animals at the beginning of the exposures, not including those deliberately sacrificed at various intervals. Death rates did not exceed those for control groups. In general, we sought to produce as high quantities of nitrous gases as were possible under any conditions resembling practical arc welding. We utilized voltages well above those commonly utilized in practical welding. We burned rods at a much higher rate than any welder is likely to do. We carried out such experimental welding in a confined*area as represented by -a thousand cubic feet with only about one change of air per hour. Notwith standing, we were unable to produce any gases or fume from bare welding rods that brought about'any readily observable injurious action on exposed animals except for the formation of methemoglobin, the significance of which is discussed in a later section. In view* of the significant absence of pathology after several weeks of exposure to nitrous gases in excess of those quantities regarded as harmful for even brief exposures, wc are disposed to question the standards that are now widely accepted and promulgated. While a few hours have been spent by humans of our own group in the gassing chamber with concentrations of nitrous gases at 84 ppm. for 3 hours, 93 ppm. for 40 minutes and 103 ppm. for 5 minutes, and while many scores of casual observations have been made upon practical welders, it is to be recognized that our outstanding evidence r. * / as to the action of nitrous puses originating in arc welding is limited to ani mals. Within these limitations, we are disposed to regard arc welding in open areas carried out with hare mild steel rods on isneoatod common types of steel as little associated with practical dangers from nitrous gases. Coated Welding Hods Thus far we have had opportunity to expose animals to the gases and fumes of but one coated welding rod. This rod presented the following approximate analysis: Moisture and volatile matter .... .......... ,SiO......................................................... .......... TiO-, .................................................... .......... MnO., ................................ ......... ....... .......... CaCO-j ................................................ ........... Mg3(P04) (theoretical) ......... ................. 8.44 20.20 43.12 11.00 4.87 13.30 100.43 The last item is open to considerable question. It is known that phos phorus is present, but in what quantity and in what form has proved to be difficult to establish. The mild steel on which this coating has been applied has not been analyzed, but it believed to conform to the common type of steel rod with approximately 93^ of iron and the remainder being made up of the following: Carbon ........................... Manganese ..................i Silicon ............................ Sulfur ........................... Phosphorus ............ . 0.13-0.1SC7 0.40-0.60'i 0.06 c/e maximum 0.04 (/e maximum 0.04 '/< maximum This coated rod was burned in simulated welding at a voltage of 45 at the rate of 46 rods per welding hour or 23 pounds per day (ignoring rod stubs). Forty animals (rabbits and albino rats) were exposed for 6.5 hours daily, 5 days per week, for 45 days. The chief atmospheric determinations were for nitrous gases and ozone. At this voltage the bare rods burned at the same rate yielded an average concentration of. TO parts of nitrogen dioxide per million. The arc shielded by the gases from this particular rod led to the formation of considerably less nitrogen dioxide, the average quantity being 33 ppm. It appears to be generally true that the shielded arc is associated with the formation of smaller quantities of nitrous, gases. Insofar as nitrous gases are the offending agents in arc welding, a prefer ence may be expressed for the coated welding rod. * . At this time, unusual interest exists in the nature of the coating mater ials for welding rods. Many partial analyses have been published, but some of these arc highly confusing since the findings on addition may total from 40 to 140f<. The chemical nature of many rods is still a well guarded secret, but it is known that an almost unlimited variety of substances have been tried out ns welding rod coatings. The number includes silica, asbestos, other inorganic silicates, organic silicates, titanium, calcium, magnesium, manganese, fluorine, aluminum, columbium, nickel, iron, barium, chromium, phosphorus, borax, wood meal, cellulose, gum arabic. sage, tea leaves, asphalt, cotton, jute, paper, cereals, string, starches, sugars, etc. Whatever 66 5* constituents enter into the rod, it is generally conceived that they serve some of the following purposes?. 1. To provide a slag coating of the metal weld during the period of freezing. 2. To furnish alloy material not present in the metal core in the rod in order that the weld itself may conform to the original metal. 3. To confute or stabilize the arc itself so that the size, of the arc is within reason constant and the flow of electric power essen tially uniform. 4. 3t is usually stated that the shielded arc excludes atmospheric nitrogen and oxygen. This possibly may he doubted and in stead possibly the shielded are alters the action of ultraviolet rays upon the atmospheric gases. To meet those various purposes served by the rod coating, highly differ ent substances enter into the coating mixture. Thus, to produce visible cloud about the are, there may be present such ingredients as cotton lint, paper, powdered cr>ke, etc. Tor the protecting slag layer immediately over t"* -vt. ing point, inorganic substances chiefly are used including borates, barium, calcium, aluminum and manganese compounds along with many others. In order to make up the deficiencies of the welding rod itself in relation to the metal to be welded, manganese, chromium, lead may enter into the coating itself. Lastly, it is necessary to b::sd these ingredients on to the rod, which calls for another class of materials, some of which in addition to being binders are gas generators. The number includes asphalt, resin, casein, ethyl silicate, sodium silicate, etc. By way of practical objections to the use of heavily coated rods, welders have indicated that it is difficult, to (1) observe the weld being made because of the overlying slag; (2) the cleaning of welds made with heavy coated rods is mere difficult than, the bare rod; (3) the increased visible clouds from the coated rods are disturbing and unwanted. A somewhat representative analysis of the coating for rustless steel rods is the following: Organic materials .................................. 19.2 % Silica (SiOa) ........................................... 22.02% Fluorine....................................................... 14.4 'A Calcium oxide and carbonate ............. 30.1 % Iron oxide ................................. .............. 1.7 % S' Manganese oxide .................................. 2.46% Aluminum oxide .....................................~ 11.1 % "V100.98% An analysis of a similar coating material for high chromium nickel rods as furnished by Captain Brown, the next speaker, is as follows: Lime ......................................................... Sodium fluoride .................................. Ferromanganese ............... .................. 30-35% 30-35% 6- 7% Silica ........................................................ Sodium silicate ................................... Cellulose ................................................. 6-7% 11% 4% 100% 67 r A**, 0^71 From the same source were obtained analyses of coatings; lor carbon steel rods: Cellulose ........................................................ 30% Asbestos ........................................................ 15 Ferromanganese ........ -.............................. 12% Titanium dioxide .................................... 12'/' Sodium silicate ............................................ 30% Lime ........................................................ Iron oxide .............................................. Ferromanganese ....................-..... Asbestos ............................'..................... Feldspar (silicate) ................-............ Sodium silicate ..................................... Pyrolusite (MnO) .......-................... 99% 5- 6% 20-25% 15-20% 8# SO# 11# ',$& + 100% While many of the varied substances that enter into the coating of welding rods well may be looked upon with suspicion as sources of injury to welders, our personal observations and conclusions are restricted to four Items related to only one type of coated welding rod, namely: 1. The shielded arc apparently diminishes the quantity of nitrous gases. 2. Significant weight and growth deviations occur. 8. The quantity of free silica present in the dust from arc weld ing with coated rods containing free silica appears to be insuf ficient to stimulate any proliferative reactions on ir.traperitoneal injections. 4. Methemoglobin is produced in the blood of animals exposed to the products of welding with coated rods. (This statement does not imply that methemoglobin is not formed from the products of welding with bare rods.) The last two items above have been made the object of further comment in two sections now following. .Methemoglobin ~* Methemoglobin and methemoglobinemia long have been associated with nitrous gases and at least casually with welding. In our early experiments, no opportunity arose for any blood counts or methemoglobin determinations. In the sixth of the series of exper iments already mentioned, methemoglobin determinations were made with the Pulfrich-Zeiss photometer, standardized respectively for male and female rats and rabbits, at the end of 45 days of exposure when the con centration of nitrous gases averaged 25 ppm. and when the voltage utilized was 45 (300-350 amp.) Table I presents the quantities of methemoglobin found in 10 male rats, together with results one week after the cessation of exposure. However, on other occasions, subsequent to exposure, the per centages of methemoglobin were in some instances higher, but always within the limits of experimental error. At the time the experimental animals were 68 01*73 t'-1 J+U r *"Si." TABLE X METIIE.MOGLOMN IN MALE UATS Percentage Methemoglobin Rat Identification 8-13-40 After 43 Exposure Days (63 Elapsed Days) to 25 ppm. NOj from Coated Rods 8-20-40 Seven Days After Last Exposure Date 1955 21.7 2.7 1953 17.5 1.5 1930 10.4 2.5 197S 14.7 4.2 1957 11.5 3.8 1969 16.0 4.2 1936 1992 | i 19SS 1963 | 16.3 10.4 13.0 18.7 0.0 0.7 S.l 2.3 - 1 Rat Identification j Controls -- Percenta8 Mathemogiobin 1945 j 0.0 (S-13-40) | 4.2 (8-27-40) 1985 0.0 (8-13-40) 3.5 (8-20-40) 09 0:1^7? 5Ci* tested (8-13-10) two control malt* rats presented no measurable trace of mcthcmoglobiu, but on other occasions methemoglobin lias been detected in. control rats up to a maximum of 4.2. However, this figure embraces the probable error circa 27t. The assumption was that the occurrence of methemoglobin was in nowise peculiarly associated with coated welding rods, which caused us to repeat for a few days an earlier experiment with hare rods using a voltage of 45. Table II presents methcmoglobin percentages just prior to exposure, at the end of one day of exposure, and three days after the cessation of a three day welding period. Although the results shown are sometimes within the limits of experimental error, the uniformity of results suggests that one day of exposure may increase the blood content of methcmoglobin, which quickly disappears by the end of the third day after exposure. During this period the average quantity of nitrous gases was 70 ppm. In the case of four welders, samples of blood collected during the period of welding work revealed respectively 2.5, 2.3, 2.3 and'2.6 per cent of methemoglobin. One human control yielded r.o methemoglobin at thi< time. 0; 13 determinations for nitrous gases made in connection with the possible exposure of these welders, the highest was 13.3 ppm. of nitrogen dioxide ir. a sample collected from an automobile body in the course of construction. The inference is that some methemoglobin formation is a common result from mild exposures to welding gases. This statement scarcely applies to experimental rabbits, which animal appears to be more resistant to methc moglobin formation.2 Should the need arise, it may prove possible to utilize the occurrence of methemoglobinemia as qualitative proof of exposure to welding gases. In the absence of other sources of methemoglobin causation, the presence of any considerable quantity of this substance in an arc or gas welder suggests exposure. The nature and physiologic significance of methemoglobin in the blood is far from dear. In congenital or familial methemoglobinemia, as much as <407cs*4 has been reported as continuous and little associated with any evi dences of ill effects. However, in many publications dealing with clinical methemoglobinemia, the method of demonstrating the quantity present may 4 be open to question. It has been stated that methemoglobinemia up to 60C5.fi of saturation is compatible with life. Other publications indicate that the behavior of the body in the presence of methemoglobinemia con forms In general to the pattern that governs carbon monoxide hemoglobin."S.M0.11.12.13.14.in It is frequently asserted that methemoglobin is a precise antagonist to cyanide action and that its presence in the blood in cases of cyanide poison ing is a fortunate occurrence. It has been claimed that methylene blue as a treatment for cyanide poisoning is efficacious from its causation of methe moglobinemia, which substance in turn combines with the cyanides with resulting body protection through the prevention of internal asphyxiation. Thus if it be true that some cyanides may be produced in connection with arc welding, the presence of some methemoglobin may serve a beneficent rather than detrimental purpose. Granting some possibility of an anti-toxic action of methemoglobin under some circumstances, it may not be inferred that the oxygen requirements of the tissues of the body may be met in the presence of any high percentage of methemoglobin, since the combination of methemoglobin and oxygen provides little or no available oxygen for tissue use. It is here emphasized that the present state of evidence is far from conclusive.TM.^!* 70 I ri& J Rat Identification 2078 2069 2082 2065 20S-1 2071 TABLE II METHEMOCLOMN IX MALE RATS 9.4.40 Prior to Exposure Percentage Methemoglobin 9-4-40 ; 9-6.40 (3 o'clock) (3 o'clock) - After 1 Day of After 3 Days _ ' _ : Exposure Exposure to 70 ppm. NOsj 'to 70 ppm. NO., i. from Bare Rodsifrom Bare Rods- A.A _ .. ,, Cessation of _ ;6*P5Ure 0.5 2.4 2.3 0.0 2.0 3.8 2.4 0.0 0.6 3.0 3.5 0.0 0.0 2.1 3.1 0.0 0.0 1.0 3.6 0.1 0.4 0.0 3.1 0.2 Rat . Identification 1964 2060 2055 1981 Controls Percentage Methemoglobin 0.5 0.0 1.5 1.8 71 0 ^ j. 7 o f j i i it f I J t i i \ * i i i f; X] SMT L& Ate. Intraperitom-al Injection with Welding Dust after Welding wilK SilicaContaining Coated Rods. Large numbers of coated rods contain Mlica or silicates. The prime use of silicate.' is as a binder for other coating materials. Organic silicates are used for tins same purpose, but this use is limited. The high temperatures (circa 0,500' F.) of the cleetrie arc may convert the greater portion of combined silicon to silica. In the analysis of rod coating materials used in one of our series of experiments, the SiO.. ranged between IT and 2Q',<. It has been computed that from the burning of a single 14", 5/32" coated rod more than 150 mgms. of fine particulate matter is introduced into the atmos phere. While this figure in itself is of little significance, it leads up to the statement that arc welding is or may be a dusty operation. Because of a maximum content of 20f< of free silica of the totai weight of the electrode of the one rod utilized by us, we collected with the electrical precipitator sufficient quantities of this dust for intrapericonoa! injections. On analysis, this dust proved to have a content of only S',;- silica, a larger percentage consisting of iron dust from the mild steel rod on which the coat ing was implanted. This material in 0.2 gram amounts suicd in saline solution was. introduced imraperitoneally into six rats, using the technique described by Miller and Sayers,TM and extensively used by us in other experi ments.1'0--1 For comparative purposes, injections were made of similar quantities of free silica, iron oxide and saline solution. Between the GOth and 70th day, these animals were sacrificed and examined. The silica used for control purposes created the expectable typical proliferative nodulation, the iron oxide induced only an inert reaction with deposits on the anterior peritoneal surface in the omentum, on the genitalia, etc.; the collected weld ing dust proved to exert only an inert reaction closely resembling that from the iron oxide. There was no suggestion of proliferation. It was concluded that dusts from coated rods containing silica or silicates, of the type used in our experiments, are unlikely to constitute any practical threat of silicosis. Welding on Steel Alloys and Welding Rods of Other than .Mild Steel In arc welding, it is frequently but not necessarily desirable that the constituents of the welding rod conform to that of the materials being welded, that is, both the metal being welded and the rods themselves may give rise to greater opportunity for injury to welders than in the case of essentially pure steel welded with mild stec-1 rods. In addition to alloyed steel, the same type of problem may arise if the metal to be welded pre viously has been coated, such as in galvanizing. The outstanding example of the adjustment of welding rods to an-alloyed steel is to be found in the relatively high percentage of chromium and nickel in welding rods for use on rust-proof steel. Such a rod may present the following approximate analysis; Carbon ........................... 0.05 n Manganese ........ .......... 1.1 Vr Phosphorus ................. 0.031'/r Sulfur ............................ 0.09 Silicon ............................ 0.43 Nickel ............................ 9.4 Chromium ..................... 19.7 <y< Copper .-.......................... 0.08 % Vanadium ......... ........ . 0.03 * Remainder Iron 72 C n o x ( L: i'i ' Vi -rf\v<-^-v:' Jm. ica- use are ires . of I in It rod tosthe ght ical >ns. g?>atline quo eriilar ;oth :SCd ion, rior 2ldom ded scd sis. the ing lay of red re* pie the jse ate A type of welding rod widely used in welds on cast iron is represented by the following: Carbon ........................... 0.11 */< Manganese ................... 1.70 ' Phosphorus .................. 0.03 *:t Sulfur ......... .................. 0.018',r Nickel ............................ 58.52 '/ Cobalt ............................ 38.5 f/e Iron .............................. 1.2 f/f 1 100.8 An analysis of another rod designed for use on chrome-nickel steel has been borrowed from the work of Captain Brown: ... ...iw...... Carbon .................................0.09 f/e JTnnfrcriAse 3.64 V Sulfur ............................ O.OOS'i Silicon ............. 0.32 f/c Nickel ........... ;............... 21.14 *,< Chromium ..................... 26.04 r.t Remainder Iron In view of the high temperature of the welding arc, almost any con stituent of the metal being welded or the welding rod, to say nothing of its coating, may be introduced into the atmosphere to some degree. Among other possibilities are zinc, cadmium, manganese, chromium, nickel, copper, molybdenum, iron, arsenic, aluminum, phosphorus, selenium, silicon, titan ium, vanadium and tungsten. Without intending to culpate any of these metals or in the case of coatings, non-metal material, it is pointed out as obvious that many of these substances arc dangerous and that some of them are present in the atmosphere about welding operations in quantities suffi cient to induce harm.-- Thus when welding is carried out upon galvanized steel more than 75'c of the fume may consist of zinc oxide. In general it is believed that in this domain may be found the truly disturbing situations connected-with arc welding. Already some complaints are arising over the possibilities of chromium from chrome-nickel steel; lead may be measured in the atmosphere near to welding on leaded steels.-,;j However, ns yet there is no reliable case record clearly associating injury with either of these metals in welding. A few deaths have been connected with welding on gal vanized steel, but to associate these deaths directly with the galvanizing or any other individual aspect of welding certainly is not warranted at tins time. Practical Applications and Implications 3. In our experience and from our appraisal of the literature, it does not appear that the health of arc welders as a class may be set apart as especially different to metal workers in general. Although occasional records of deaths appear associated with some aspect of welding as the cause, we have no evidence of any prevailing diseases characteristic of the work of the arc welder (radiation effects excepted). 2. In our experimental studies, with the rate of rod burning much higher than in practical welding, and with welding confined to a compara tively small chamber of 1,000 cubic feet, with at times only one air change 73 7? 6 * *u. per hour, \vc have not been able to find any suggestion of oxygen deficiency. 3. The much discussed point of ozone formation in the welding arc has in our experience resolved itself as follows: Much ozor.c (10-32 ppm.) is produced immediately in the are, but quickly is diminished (1-9 ppm.) a few inches (-1") away from the are and in the center of the chamber the residual is not more than 1 ppm. of ozone. Although this exceeds the somewhat accepted threshold of injury of 0.4 ppm., no injury from this gas has been determined by us. 4. Kunv-rous tests for carbon monoxide have been made under various conditions--always without any significant results. 5. Other things being equal, low voltage and amperage are desirable in arc welding, since it appears to be true that low voltage is conducive to the low formation of nitrous gases. 6. Our best efforts to produce from arc welding sufficiently high con centrations of nitrous gases to induce injury to animals after long exposure were not successful. Practical arc welding in open areas seldom V*Js to higher concentrations r.l -..i'.vous gases than 20 ppm. 7. It is cur observation that concentrations of nitrous gases near the widely accepted threshold of 39 ppm. are quite harmless to laboratory ani mals after prolonged exposure and further that double this quantity for. prolonged exposures and treble this quantity for limited exposures likewise are without discernible ill effects on animals. Human beings exposed to such quantities ns 84 to 103 ppm. of nitrous oxides for a few hours (three) suf fered no ill consequences. 8. TVe possess some evidence that mothomoglobin is formed both in laboratory animals and human beings exposed to welding gases, but the quantity of this methemoglohm appears to be without injurious propensities and further there is theoretical evidence that comparatively low percentages of methemoglobin in the blood may under some circumstances serve benef icently. 9. Limited experimental observation is unfavorable to any belief that silicosis may be brought about from silica dust exposures incident to arc welding. 10. The heavy iron content of the air incident to animal exposure in welding has not been shown, from clinical, x-ray and autopsy observations, to produce any injury beyond pigmentation., _ 11. Apparently coated rods are to be favored over bare rods insofar as the production of nitrous gases is concerned. 12. Finally, in appraising arc welding as an Industrial procedure essential to national defense and with particular reference to hygienic prob lems we at least are convinced that some over-emphasis in the past may have been placed on the significance of nitrous gases, carbon monoxide, ozone and iron fume. To the contrary, if there be practical hygienic problems related to arc welding (in addition to the obvious ultra-violet emanations) these may be expected in the little explored field of the constituents of coat ings on rods, coatings on metals, and special constituents of the metal weld ing rod or the metals being welded. 74 /) n v j.1 j U VAVW!? -'V^TT ySll s y. rc ut in e. ),4 us / !e to >nire to the .nifor 'ise uch uf- in the ties *es lef- hat arc * in mis, >far lure rob* nay ;or.e ems ms) CITATIONS j. Jlnirold, G. C.: Meek. S. F.; and MoCnul, C. t\: A Chemh-al ami Physiological Investigation of Fleet! Ai** Welding. I. Bure. Washed Welding Rods. J. Indus. Ilyg. & Tux. 22: 34; (Ort.) )94j. 2. Heubner, W.: Formation of Methcir.oglobin. J. Pharmacol. 30: 273, 1027. 3. llitzenbergor. K.: Autotoxie Cyanosis (ttitraglobulnr methemoglobinemia). Wien. Arch. Inn. Med. 22: $3. 1022. 4. Hensley. E. II.: Rhea. I- J.: and Mills. E. S'.: Familial Idiopathic Methemo globinemia. Quart. J. Med. 7: 323. 1013*14. 5. Rosenberg, V. X.: The Detoxifying Action of Methemeglnbin Forming Agents in Sodium Azide Poisoning. .1. Phjsiol. <1.*. S. S. H.) 22: 1S4, 1037. 6. J.lpschitx, W.: Aromatic Niiro and Amino Compounds as Blood Poisons. JJentr. Cewerbehyg. I'nfaUverhat 14: 11. 7. Sotandt. O. M.; Rolandt. p. v.: Hess, K.: nnd Gerjtrd, R. W.: Mcthemogiobln ami Methylene Flue as Cyanide Antagonists. Proc. Soc.Exptl. Biol. Med. 31: 539. 1934. R. HaurowJtz, F.: XIX. Methmioglobin and Its Combination with Hydrogen Per oxide, with Cyanides. h.?.imrs and Sulfides. 15. Physiol. Che:::. 222: ms, 9. Hup, 1'.; and Morenzl, A. R.: The Fixation of Hydrocyanic Acid by Erythro cytes Containing M.-thvmo"lobin. Compt. rend. soe. tiol. 114: $4, 1933. 10. Warhu.;:. O.: Kubowiiz. F.: and Christian. W.: The Catalytic Action of Meth ylene Blue in Eiving Cells. Bioclicm. Z. 227: 245, 1930. 11. Moller, K. O.: The Significance of Methemoglobln Formation in the Intoxica tion of Cyanic Acid by Methvlene Blue and Sodium Nitrite. Skand. Arch. Physiol. 73: 2G7. 12. Wendel. W. R.: Oxidatbns by Erythrocyte* and the Catalytic Influence of Methylene Blue. II. Meth. ninglobln and the Effect of Cyanide. J. Biol. Chem. 102: 375. 1933. 13. Karasik. V.; Rozhkov, V.: and Vinogradova. O.: Preventive Action of a MethemogloWmxlrg Ac>tu. Sodium Xitrh-. in Fluoride Poisoning. Compt. rend, soe. bird. 119: SOT. 1935. 14. Vinogradova. 0. G.; and Rozhkov. V.: Methemoglohin Builders as Antidotes in Fluoride Poisoning. J. Physiol. (L\ S. R. R.) 19: 5S3, 1935. 15. Frlofeld. H.; R'-hiU-wa. A.: and J.udwlnowskv, R.: Heinz Bodies and Methemo glohin Formation in Poisoning bv Compounds Containing Amino and Xitro Groups. Folia Haematol. 56: 323, 1937. 1C. Roche, J.: Physiological Action of Methemoglohin Formation in the Blood. Areh. Intern. Pharmacodynamic 37: 335, 19S. 17. Rabbono, A.: and Rappeport-I.ewey, S.: Metbemogb'Mnizing Effect of Sodium Nitrite in Vivo. Boll. soe. ital. biol. sper. 11: 34, 1S3C. IS. Kcilin, I>.: and Hartree, E. F.: Reaction of Nitric O^ide with Hemoglobin and Methemoglobin. Nature 139: 54S, 193". 19. Miller. J. \V.; and Sayers. R. R.: The Physiological Response of Peritoneal Tissue to Busts Introduced as Foreign Bodies. U. S. Pub. Health Rep. 49: Sfi, i;i54. 39. McCord, C. P.; Fleming. R. I*.; Atnslee. U.; and Johnston. J.: The Measure ment of th<- Harmftdncss of Dusts for Humans Through the Agency of Animal Reactions. Ruig., G>ne. ar.d Obstot. 63: 129 (Aug.) 1934. 21. McCord. C. P.: Kasper. J. A.: and Brosius. W. L.: A Biologic Test for the Determination of the Fibrog**notic Properties of Bust. Ohio State Med. J. 33: *94 (April) 1557. 22. Ptibre, R.: and Kalian*. M. E : A Toxicological Study of the Principal Constit uents of Si*viin) Steels. Arch. ds mal. prof. 2: 265, (Special No.) (May) 1939 (French). 23. Halley, J. W.: ami Martin, E. D.: Read-Bearing Steels: Control of Possible Health Hazards During Fabrication. Metal Prog. 37: 412 (April) 1949. 75 PROFESSOR DRINKER: We welcome any discussion on tins paper or questions to I)r. McCord. DR. SANDER: I should like to ask Dr. McCord what he meant by the possible protective action of mcthemoglobin formation. DR. McCOKD: 1 am very clad to go into that, blit I do want to confess that nobody can be sure of that situation and instead of relying upon my own offhand comment here I wish to refer to my notes in that connection. In the first place, methcmoglohin may not be highly dangerous in itself. There are several cases on record of familial methcmoglobin anemia which, according to methods that were usyd for testing, and some of those may be doubted, yielded up to forty per cent of methemoglobm in the blood without any apparent disturbance to the owner of that particular congenital defect. In a much larger number of cases the quantity of mcthemoglobin contin ually present has been on the order of twenty or thirty per cent. From the work on methylene blue in the treatment of cyanide poisoning and that type of poiau.xug, it apparently has been established or may be established that the only good or the chief good that the methylene blue does is to form mcthemoglobin, and the methcmoglobin in turn acts as a direct antagonist to the cyanides. We have no proof yet that cyanides or nitriles, which are about the same, are produced in connection with welding, but we have some vague belief that such is the case. On the assumption that these cyanides or nitriles may arise we believe that they might be overcome or destroyed because of their combination with or because of an antagonistic action of methemoglobin, which apparently readily combines with cyanides and that type of chemical in the body. PROFESSOR DRINKER: One of the largest, if not the largest, em ployers in the country today, in the factory sense, is the United States Navy. The Army will shortly be, if it is not already, in just about the same cate gory. In the production program and the accomplishment of our desire to have a two ocean navy, our navy yard.* have necessarily become enormous producers and enormous employers of labor. Their industrial hygiene prob lems are therefore just those that would be created by such a huge expan i sion necessarily made without as much time and preparation as we would like. I personally have had the pleasure of knowing the next speaker. Cap tain Brown, for a number of years. In industrial hygiene matters I first met him in connection with the dismantling of ships and the industrial hygiene problem that that created. Nowhe-is in charge of the medical aspects of one of the largest yards in the world. - It is a great pleasure to us to have here today Captain Ernest W. Brown, of the Medical Corps of the United States Navy. ; 76 01*09 '*'w` .i tv a ,, INDUSTRIAL HYGIENE AND THIS NAVY IN NATIONAL DEFENSE CAPTAIN ERNEST \V. BROWN (MC), U. S. N. J. Introduction One of the most important concerns of the Medical Department of the Navy today is industrial hygiene and especially in Navy Yard practice. This is a situation of ever increasing moment in view of the present era of enor mous expansion in naval construction, unparalleled in the history of this country. This is bringing about a vast increase in the industrial force of our Navy Yards and, in all probability, new problems in industrial hygiene will emerge, incident to new materials and processes. It should be remembered in this connection that the policy of the Navy Department is to allot new naval construction on an equal basis to govern ment and commercial yv/is follows that the commercial establishments are also undergoing rapid development with an enormous rise in industrial personnel. They will therefore be confronted with the problems of industrial hygiene similar to many of those arising in Navy Yards. Industrial hygiene is a field which is now undergoing rapid development. This appears to be due to certain significant trends, the most important of which has been the recent setting up of many Industrial Hygiene Units in state or city Departments of Health through funds released by the pas sage of the Social Security Act. These trends, in fact, particularly that just mentioned, reflect a definite renaissance of industrial hygiene as a phase of public health in the United States. This movement is receiving increasing recognition in naval industrial circles, and industrial hygiene is now listed as a specialty of the naval medi cal officer along with other specialties outside of the purely clinical fields, such as aviation medicine, submarine medicine, chemical warfare medi cine, etc. Those just mentioned, however, are concerned primarily with naval personnel. Industrial hygiene, on the other hand, is largely occupied with federal industrial personnel. It therefore follows that the status of the Senior Medical Officer of a major Navy Yard in relation to the Industrial Depai'tment is analogous in many respects to that of the Medical Director of a large commercial industrial plant. The object of this paper is to pre sent an outline of the administration of industrial- hygiene in Navy Yards which are the chief industrial units of the Navy. Mention should he made in this connection of the Sub-committee on Industrial Hygiene of the Health and Medical Committee of the National Defense Council which has recently been established. The Surgeon General of the Navy is represented by liaison officers in conjunction with this Sub committee. Important recommendations pertinent to the Navy and indus trial health will result and many of them will undoubtedly be put in effect. . The term, industrial hygiene, as applied in the present discussion, is used in the specific sense of the prevention and control of occupational disease. The fact may be of interest that the first compensation law for occupational' diseases in this country was one passed in 1003 by Congress for U. S. Civil Sendee employees. Compensation laws for industrial diseases have lagged far behind legislation covering accidents. Only 36 states of the Union pro- f / Si f f; vidod compensation for one or more occupational diseases up to the year 1937, although all but two provided legislation for .accidental injuries; 2. The Industrial Organization of Navy Yards The mission of a Xavy Yard is primarily the construction, maintenance and repair of naval vessels. The central administration of Xavy Yards, and in fact, of all industrial shore stations of the Xavy, is vested in the Assistant Secretary of the Xavy, in whose office is the Shore Establishments Division of the Navy Department. There are eleven Xavy Yards located as follows: Portsmouth, X. H.; Boston; Xew York City; Philadelphia; Washington, D. C.; Norfolk, Va.; Charleston, S. C.; Mare Island. Calif.; Puget Sound, Wash.; Pearl Harbor, Hawaii; and Cavite in the Philippines. In addition, mention should also be made of the following specialized in dustrial plants: for the building of submarines at Portsn>Quthf X. H. and Mare Island, Calif.; the Naval Gun Factory at the NavyYard,'Washington, D. C., for the production of I.IBh v.wiber naval guns, torpedo tubes a ru accessories; the torpedo factories at Newport, R. I., and Alexandria, Va., for the manu facture of torpedoes; the powder plant at Indian Head, Md., for the produc tion of Xavy smokeless powder; the aircraft factory at Philadelphia for experimental air craft construction and tepair; the naval armor plant at Charleston, W. Va.; and the Naval Clothing Factory at Brooklyn, X. Y. Organization of the Xew York Navy Yard: The organization of the New York Xavy Yard may be taken as typical of a major yard. It falls under two departments, j. e., the Industrial Department headed by a naval captain of the engir.vcrir.g branch and an Operations or Military Depart ment under the direction of a naval line captain. As a conservative esti mate it may be stated that 90r> of the activities of a Xavy Y'ard are Industrial. Under the Industrial Manager there are at present twenty-three shops of different types with a force per shop varying from 30 to 3,200 men. The total of civil employees of this yard is now 17,000. This is rapidly rising and, it is estimated, will exceed 20,000 in 1941. 3. Extent of the Civilian Industrial Force of the Xavy The combined industrial force of all Xavy Yards is now approximately 100,000. In view of the pending program of naval construction it is esti mated that this will reach 130,000 in 1941. If inclusive of all shore stations this would probably be close to 160,000. In addition to the industrial force of Navy Yards we should also con sider the employee volume in the commercial naval ship building plants such as the Newport News and Dry Dock Co., the Xew York Shipbuilding Corpor ation at Camden, X. J., and the Bethlehem concern at Quincy, Mass., which now employ from 12.000 to 15,000 men each. It is a conservative estimate that the combined industrial personnel of all such plants on both east and west coasts will reach a peak of over 100,000. 4. Organization of the Medical Department of a Xavy Yard The medical staff of the Xew York Yard consists of 10 medical officers, 5 dental officers, 1 nurse, 45 enlisted men and 2 civilian clerks. The chief activities with reference to industrial personnel may be summarized as fol- 78 fowl 4-iirIfawa; lows: (a) Pre-employment physical examinations: all applicants for federal jobs are examined physically, although the standards for acceptance vary to some extent for different occupations, (b) Periodic physical examina tions: these, of course, are conducted with the object of medical supervision of certain groups of employees exposed to definite potential health hazards, as foundrymon and spray painters, (c) Physical examination of federal employees for retirement: this is for evaluation of degree of disability and opinion as to disposition when total disability is alleged, (d) Diagnosis, treatment and disposition of industrial injuries and occupational diseases, (c) Administration of compensation cases. <f) Industrial hygiene and plant sanitation. 5. The Industrial Medical Officer An officer of the medical staff of the Navy Yard is specifically detailed for industrial hygiene administration subject to the direction of the Senior Medical Officer. The accompanying slide outlines the. scope of his activities. (a) Advisor to the Engineer: The adequate practice of industrial hygiene in Navy Yards, as in civil industry, is dependent upon the close and efficient correlation of the safety engineer and the industrial medical officer. It is essential to obtain a grasp of the functions of both of these officers in order to properly visualize industrial business administration. (b) Inspections: The industrial medical officer is responsible for the general supervision of plant sanitation, i. e., ventilation, illumination, water supply, general cleanliness, adequacy and condition of sanitary facilities, etc. He also conducts shop inspections for occupational health hazards and their measures of control. He cannot expect to evaluate working conditions and thereby detect occupational health hazards early unless he makes periodic inspections through the plant. In this way he can observe the adequacy of existing measures against specific hazards and whether such methods arc being prop erly utilized. These inspections also have a.psychological value in that they create greater respect for the medical service in the minds of the employees. (c) Supervision of Special Physical Examinations: pre-employment cases when the applicant reports previous exposure to potential industrial health hazards such as lead fumes or foundry dust; periodic examinations of groups exposed to such potential occupational hazards, as spray painters and sand blasters; examination of cases referred for transfer to other shops where there is a question of occupational disability; clinical studies for a decision as to industrial origin in obscure cases. *** (d) Medical surveys of occupational groups; this will be discussed later. (e) Administration of the medical aspects of compensation claimed for occupational disease pending before the U. S. Employees Compensation Com mission. (f) Supervision of preparation of accident and occupational disease reports for the Navy Department. 6. The Safety Engineer A civilian Safety Engineer is stationed at the Navy Department as the advisor to the head of the Shore Establishments Division. A naval officer is assigned to each Navy Yard as the safety engineer. 0) Accident and unsafe practice control: Safety engineering is one of 70 to;.- MR law. the divisions of the Navy Yard organization*. The Safety Engineer conducts an investigation of ail lost-time accidents with a view to fixing the cause and advising as to measures to prevent their recurrence. The basic features of approach to the safety problem in Xavy Yards are provision of safety devices, such ns mechanical guarding, and the safety education of workmen and their supervisors. Another important aspect is the competitive approach which has proved very effective in stimulating interest in accident prevention. The Xavy Department publishes the comparative safety scores of all Xavy Yards monthly. The accompanying slide emphasizes the advance made by the Xavy Department in accident reduction beginning with an intensive safety cam paign in Xavy Yards in 1926. We find the frequency accident rate lowered from 20 to practically 10 per year in a 12 year period; the severity rate reduced from 2.2 per year to 0.5. On the other hand it will he noted that the total man hours worked during the period increased to 115 million from 65 million per year, tire average number of employees-rising from approxi mately 30,000 to- 66,000. .... (2) Occupational Health Control: The control of occupational disease in Navy YaTds naturally lies within the sphere of both the safety engineer and the industrial medical officer. Although the safety engineer is adminis tratively charged with this task, the medical officer is actually coordinate with him in this phase. As a matter of fact, the medical officer is the key man in the prevention of industrial disease in Xavy Yards, in that he usually discovers its exis tence. The diagnosis having been made, the occupational history and the pre-employment examination record are carefully reviewed in order to reach a decision, if possible, whether the hazard can be traced to present or past employment. If ascribed to, or aggravated by environmental conditions, the medical officer confers with the Safety Engineer and an industrial hygiene survey is usually recommended to the Commandant. 7. The Industrial Hygiene Survey - Such a survey is of course a combined medical and engineering task. (a) The Medical Survey. This consists of a complete clinical study with detailed occupational histories of all exposed personnel as a case finding procedure under the supervision of the industrial medical officer. Although not directly responsi ble beyond the matter of the medical survey, it is important that the medical officer have a reasonable grasp of the entire problem so that he will be in a position to utilize all data that have any bearing on the interpretation of his medical finding*. In addition, he may act in an advisory capacity to the safety engineer with respect to certain technical phase's in the planning and conduct of the engineering aspects of the survey. (b) The Engineering Survey. The engineering phases of an industrial hygiene survey in a Xavy Yard fall, naturally, under the direction of the safety engineer. As in a commer cial industry, this embraces essentially a complete story of the occupational duties, physical conditions of work, and the materials, processes, and equip ment of the individual shop, in other words, the environmental conditions. Laboratory facilities: There are no facilities provided for technical 80 studies tn the Xavy Yard organization ami there is no central laboratory unit in Washington which could supply industrial hygienists for field studies, 'this is an urgent need and recommendations have recently been made to the t-nd of setting up such an agency. The Department has been most fortunate in the past in securing the services of the Division of Industrial Hygiene of the Public Health Service to conduct such technical studies much in the same wav that industries in the states utilize the facilities of State Bureaus of Industrial Hygiene. The safety engineer formulates the control program of the health haz ard on the basis of the data of the survey. After all, once the etiology is disclosed prevention of occupational disease is largely an engineering problem. t 8. The Reporting of Industrial Accidents and Illnesses An important advance in accident prevention by the Navy was initiated on July 1st of this year when the Secretary directed that a report of each accident and illness, bc*h "lost-time" and **no lost-time," occurring among civil personnel of Navy Shore Establishments be made to the Bureau of Medicine and Surgery. The report of each accident is submitted on a form, known as F-C, shown in the accompanying slide. This presents the diag nosis of the injury and the essential details as to the cause. Punch cards are made up from these records for mechanical tabulating and indexing through a sorting machine. This provides facilities for the statistical analysis of these accidents and diseases, and the data obtained promise to be a farreaching contribution to the subject of accident control. Prior to this system a crude form of accident reporting to the Department was in effect but it was not adapted to statistical analysis. 9. Occupational Health Hazards in Navy Yards The chief potential occupational health hazards in Navy Yards will now be considered, the data being based chiefly on reports to the U. S. Employ ees Compensation Commission over a series of years. It hardly requir-s emphasis that industrial medical officers must be constantly on the alert for new hazards. (1) Dust Diseases. (a) Silicosis: Important units of all Navy Yards are iron, steel and brass foundries. The dust control problem is a major concern.in these plants as in civil industry. One of the difficulties met with in combating the foundry dust problem in navy yards is the fact that silicosis dust is not particularly irritating or obnoxious in concentrations which may ultimately lead to pulmonary dam age. As a result we find a tendency to an indifference on the part of the workers and even supervisors and executives, which must be overcome in order to accomplish effective and permanent dust control. Another reason for this attitude is the long period of time necessary for those foundry work ers exposed to only moderate concentrations of dust, such as molders, to develop silicosis. A medical survey of the foundries of the Navy Yard, Washington, D. C., was conducted by the speaker in 1939: of 525 men x-rayed, approximately 60# had a record of 10 years or over; and 30# a record of 20 years or over SI / - *# of total foundry employment. Twelve case* of silicosis were found or 2.4't of the total--nil in Stage I or II; these data leading to recommendations for improved dust control methods. Industrial hygiene surveys in foundries other than the Washington Navy Yard have not as yet been carried out hut would, in all probaVnlvly, disclose a certain incidence of silicosis, oven if not of disabling type. The medical control of silicosis in the naval establishment consists of an x-ray of the chest before employment and an annual radiograph of all men. exposed to the higher silica dust concentrations such as sandblasters and shake-out men. It is believed that medical surveys of foundries in all Navy Yards will soon be required. / (b) Asbestosis. i This is a potential occupational disease hazard from the inhalation of asbestos dust among workers engaged in the manufacture of asbestos insu- latihg covers for flanges, valves and high temperature steam turbines. f The speaker recently conducted a medical survey of the workers of the j Pipe Insulating Shop of the New York Yard inclusive of x-ray st*'*1'"-. the | maximum working period of exposure being 17 years. No asbestosis eases I were found. Similar findings have been reported from two other yards but the study should be extended to all men in this trade. Medical control consists of an x-ray of the lungs annually. The asbestos is moistened and localized exhaust ventilation is installed over the work area. A respirator is worn during the dustiest aspect of the process. (2) Lead and Lead Compounds. Lead poisoning has become comparatively infrequent in recent years both among industrial and service naval personnel; apparently due in part to changes in materials and methods, and partly to improved measures of control. Zinc and titanium paints have largely replaced leaded material Iot ship interiors. Ked lead paint is still in use as the priming coat on hull exteriors but the finishing coats contain either no lead or a greatly reduced proportion. All painters regularly handling lead-containing paint are exam ined semi-annually for evidences of lead absorption. (8) Volatile Organic Solvents. Lacquer spray painting occurs .on an extensive scale in Navy Yards and therefore demands rigid medical supervision. Another important appliea tion is in degreasing measures. All spray lacquer personnel are subject to -semi-annual physical examination. (4) X-ray and Radium Hazards. The x-ray and radium are continually utilized for the detection of flaws in castings and pipe welded joints for high pressure steam installations. Radium has an advantage in the small size of the equipment in that it is adapted to tests in the confined machinery spaces of ships. The question of protection from irradiation of the operating and other personnel working in the vicinity of the apparatus has received thorough study, the practice of the Bureau of Standards being generally followed. Complete blood counts of all technicians are conducted quarterly and special pre-employment examinations are prescribed. Another potential hazard of radium is that of ingestion incident to radium painting of luminous dials, more especially for fire control instru- 82 o ^ -- j< 'a mcnts and aircraft. The control measures advised by the Public Health Service are generally in force, plus certain local regulations. (5) Welding. The hygienic supervision of welders is another outstanding feature of medical responsibility. Approximately 2,500 welders were on the rolls of tho combined shore establishments as of January 1, 1910, including 653 at New York. This number has progressively increased and will continue to rise. The immense volume of work in confined spaces is characteristic of naval welding. A battleship of 35,000 tons displacement under construction contains approximately 500 compartments in which electric welding is mandatory, certain of these spaces being extremely small and forcing the welder to work in very cramped positions. ^These conditions complicate the question of effective preventive control of the hazards. The chief hazards which have to be considered at presenti.are "nitrous fume" poisoning, zinc fume fever, as it is popularly termc4^and actinic ophthalmia from ultraviolet radiation of the Welding are. - "Mtrous fume" poisoning, while comparative., raic, is a serious condition. No accent need be placed on the fact that these injuries would be still further reduced in number if the control measures provided were properly utilized. It may be of interest to note that of SIT cases of actinic ophthalmia reported at the New York Yard in 9 months of the current year, only 2Gr/c occurred among welders; the remaining 80^ among men exposed in spaces adjacent to the welding arc but not utilizing available protective goggles. Chronic poisoning among naval welders from manganese, fluorides or silicon, which might be ascribed to inhalation of these metallic or mineral oxides in the welding fumes originating in the rod coatings, has not been reported. Such a possibility, of course, cannot be denied. The limitation of time prevents mention of additional hazards. 10. Annual Examination of Crane Operators, Enginemen (Hoisting and Portable) and Locomotive Engineers These classes of workers are physically examined annually with special emphasis on blood pressure, hearing and vision. In view of the nature of their duties, pliysical failure, such as sudden collapse, might involve critical injury to themselves and others; and in addition, damage to material. If corrective measures are impracticable the worker is retired or transferred to'some other type of employment for which he may be suitable. A crane operator, for instance, presenting a marked hypertension.'would be referred to his private physician and transferred to other duties. 11. Time Loss from Industrial versus Non-industrial Disabilities In a limited study of 116 industrial companies in various parts of the United States conducted by the American College of Surgeons a few years ago, it was found that the time loss from non-industrial types of illness was approximately 15 times that industrially connected. The speaker in his capacity as Senior Medical Officer of the Washington Navy Yard made the following observations for the calendar year 1935: Total industrial force, 7,000; number of days lost from industrial accidents, 0.14; number of days lost from non-industrial illness or accident, 5.20. The number of days loss from non-industrial disability was therefore 37 times that from industrial 63 causes. A simitar study by the speaker at the New York Yard for 1939 ;j'Cvea!od that the non-industrial loss was roughly four times the industrial figure. The possible factors in the difference between the two yards have .not been analyzed. Disparities of the same general order have been reported in recent sta tistical studies by certain large commercial industries and reflect an enor mous economic loss. Much of this, non-industrial illness is preventable. It is believed that in the naval establishments this wastage of preventable illness can be greatly reduced, if the problem is attacked by an annual physi cal examination of all employees, referring cases requiring corrective treat ment to their private physicians or other agencies. This would require a heavy increase in medical staffs but it would be a profitable investment by naval industry in the saving of man power for national defense. It is a question worthy of being explored. PROFESSOR DRINKER: We were informed the other day in Wash ington that the Navy is now in the mining business and is confronted with the conventional mining hazards as well. Therefore we can say that tneir hazards are about all those we meet in all of our industries. J am sure that Captain Brown will be glad to answer questions. MR- WEIL: I should like to ask Captain Brown what his eye test con sists of for his men in so-called key positions. We are using a keystone and we are a little at a loss as to how to interpret some of the findings. CAPTAIN BROWN: I didn't get the drift of that. f MR. WEIL: I want to know what the eye examination consists of and what is your experience in interpreting the keystone test, if you use it. CAPTAIN BROWN: I don't think we have had any contact with that particular test. We simply use the ordinary southern test, with definite i \ standards. PROFESSOR DRINKER: A teacher always judges the value of a book, first, by his ability to keep it in his own library or in his own laboratory. They have a way of disappearing, particularly if your students are eager for it. One also judges the value of a book by the general appearance of the .cover, whether it begins to fall apart after a month or two. i Haggard's "Noxious Gases" is the standard book throughout the Eng lish-speaking world on the subject. I am on my fourth copy. I don't know how the rest of you are doing. Two of mine have been stolen, one is worn i \ out, and the one I have has been rebound once. The University also has a number of them at the Medical School and at the Engineering School Libra ries. I state this to show you how eager we are to use it and how much we do use it. It is pleasant to welcome to our group--at least it is for me as a pro fessor at Harvard--a professor in a sister university and one with whom we have friendly rivalry of all sorts. In this case I have to admit, with a good deal of professional jealousy and very sincere admiration, that there isn't any rivalry. The lead is entirely with Yale. It is to me, therefore, a great personal privilege to be able to introduce to you Dr.' Howard W. Haggard, of Yale University, who will speak on the "Absorption and Excretion of Volatile Solvents." 84 o t * () k i *.* T I ! 3 It 1 t 1 I 5 > l ABSORPTION AND EXCRETION OF VOLATILE SOLVENTS HOWARD W. HAGGARD, VI. D.* As I look over the program for this symposium, I am struck with the fact that the title assigned to me seems a little incongruous among the other titles, which are definite, practical, ami immediate in their bearing on the problems of Industrial Health Defense. Air contamination with volatile solvents and kindred substances is a potential and real hazard in many industrial occupations. It is a practical problem of growing importance, ltut here I deal with no occupation, with no particular solvent, and with no particular situation. And for very definite reasons. There has been in this field far too much empirical, tabular information, and far too little concep tion of fundamental principles. The general problems of thc-se hazards-- and the specific problems--cannot be dealt with intelligently by treating each volatile product as an entity with as many individual and separate problems as there are individual volatile products. Rather, I believe, the problem should be approached by way of general principles applicable to all volatile solvents. These principles deal mainly with the peculiarities of respiratory physiology--with the peculiarities of the process by which volatile solvents get into the body and by which they leave the body. It is only in the light of these principles that such features as concentration in the air and dura tion of exposure take on significance. These, then, are the reasons for my topic. But I offer no similar defence for the fact that in dealing with it I shall at moments descend to some very elementary physiology and to some very obvious situations. Toxic substances, aside from surface irritation, with which I shall deal separately, exercise their detrimental action or.ly after they are absorbed into the body. And, so far as ultimate effects are concerned, the body makes little distinction as to mode of entry. Thus ethyl alcohol, to deal with a fairly familiar volatile solvent and the one with perhaps the lowest toxicity of any-- when absorbed into the body causes certain physiological effects, the severity of which are roughly proportional to the amount of alcohol absorbed. This action--again barring local irritation--is not exercised at the point of entry. When alcohol is taken by stomach it passes through the walls of this organ and of the intestines and dissolves in the blood. By the blood it is carried to every part of the body. If it remained exclusively in the blood, no intox ication would occur. But the blood exchanges with the tissues ali soluble S substances. Consequently, part of the alcohol leaves the blood and dissolves i in every tissue of the body to an amount proportional to that in the blood in the relations of the solubilities of alcohol in blood and tissue. The body is thus permeated wiih alcohol and a tension of alcohol built up iiu the tissue?. This tension, and correspondingly the amount of alcohol in the tissues, are proportional to the amount absorbed. The alcohol c.vuses little or no disturbance in the functions of most of the tissues of the body, but on one in particular it has an especial effect-- the hrain. Brain function is altered; the various symptoms of drunkenness develop. Those functions which have been acquired last in evolutionary development appear to be affected by the lowest tension; thus judgment and reason are impaired early, then temperament, then coordination, then con sciousness, and finally, if the tension increases sufficiently, the nervous center * Director, Laboratory of Applied Physiology, Yale University. So 0 of respiration is paralyzed and breathing stops. Many other solvents are likewise anesthetic and exercise their action In this manner; and some have additional toxic actions. The point I have tried to make here is that what I call the ultimate effects--the distribution of the solvent throughout the body by way of the blood and its particular action on some tissue or function of the body--are independent of the manner in which the solvent enters the body. To con tinue with the solvent which I have chosen for illustration--it may, and often is--taken by stomach; but it can just as well be absorbed into the blood, and the man will be just as drunk if, instead of being swallowed, it is injected hypodermically, intravenously, intrapeiitoneally, or taken as an enema. Hut there is one important point in regard to these forms of absorption. A man can choose what he swallows and when he will swallow it; he is rarely insulted with the other forms of absorption that I have mentioned. But there is one mode over which he does not have this discretion--that is, absorption from the respiratory tract. A man cannot select and choose that part of the air which, he wisnes to breathe or refuse entirely to breathe; 3e must breathe the air under the conditions in which it is present. Conse quently any volatile solvent in the air enters the lungs and from the lungs it is absorbed into the blood and by the blood it is distributed to every tissue in the body. It does not follow in consequence that the man so exposed will be ren dered ill or poisoned. That will depend upon how much of the solvent he absorbs. Ami that in turn depends upon the principles of absorption and their concomitants: concentration, length of exposure, volume of breathing, and solubility of the solvent. In dealing with these* principles, consider with me first the general arrangement of the respiratory system. This system, is first and foremost adapted for the instantaneous absorption of gases and vapors; that is the normal function to which it is specialized. The absorbing surface, which is that of the minute air sacs of the lungs, has an area approximated at SO square yards; it lias an infinitesimal thickness. On one side of it is an in credibly fine network of capillaries through which at every round of the circulation all of the blood passes from the right to the left side of the heart. On the other side is the air of the lungs. To all practical purposes the blood and air are in contact; they are in gaseous equilibrium. In breathing, a stream of atmospheric air passes into the lungs but not continuously; instead, intermittently with the reciprocal movements of breathing. On expiration the lungs are not emptied of air; only a small part of the total amounr present is displaced and renewed with air drawn from the outside. The membrane of the air sacs is extremely delicate and would be injured by contact with air at the extremes of temperature and moisture which exist in the atmosphere. The remainder of the respiratory tract--the nose, tra chea, and bronchial tubes--are much less delicate and they serve as a highly effective air conditioning device to warm the incoming air to a temperature nearly that of the body and to moisten it to nearly lOCK-o relative humidity at this temperature. I shall not pause to dilate upon the marvelous efficiency of this system; I bring it up here because I want to deal with it in a digres sion on local irritation from volatile solvents present in the aiv. The air passing through the upper respiratory tract is buffeted against the walls of this tract so that all of the air comes in contact with them. These walls are moist with a clear mucous secretion. This mucus dissolves some of the solvent; the amount thus dissolved, the concentration developed 86 jn the fluid bathing the surface, depends upon the concentration of the sol vent in the air and its solubility in fluid. And as I continue here, I .shall emphasize and re-emphasizc the important part that solubility of the solvent plays, not only here but also in the process of absorption, to which I return in a moment. As I said, some of the solvent in the air dissolves in the film ef fluid in the nasal passages, the trachea and the bronchi. If it is very soluble, a considerable amount will dissolve. It may be absorbed from the surface, but it may also irritate it if the solvent is of a sort that on contact will injure tissue. And I have only one remark on irritation. The initial injury to the surface may be too slight to be perceived; the ill effects result from the inflammation that follows. Inflammation is a vital response; it does not occur in the dead body. The situation here is precisely as it is with sunburn; the initial injury from the actinic light may not be particularly evident; the "burn" develops sometime later when the body responds to the injury with inflammation. In respect to solvents--if they are irritating--the irritation is greatest ir. the upper part of the respiratory tract if they arc highly soluble in water, and in the deeper part of this tract if they are only slightly soluble. This dis tinction, which depends upon site of major accumulation on.the and upon the sensitivity of the deeper surfaces, is far more evident with some noxious gases than with the volatile solvents. Thus ammonia gas, with its high solubility, causes immediate and intense irritation of the nose and throat,, while phosgene, with its comparatively slight solubility, is not so completely absorbed in the moisture on the surface of the upper respiratory tract and consequently exercises its major, and far more serious, damage on the lung3. And here I ask you to visualize with me the essentials of the respiratory system in a little more detail than in my discussion of a few moments ago. First: an enormously large membrane--the air cells of the lungs--with blood on one side and air on the other; and with free and immediate diffu sion of any gas or vapor across the membrane into or from the blood. Second: a regulated volume of blood--which I shall henceforth call the rate of the circulation--flowing through the lungs and exposed to the air for the exchange of volatile substances. This volume varies somewhat as be tween different men and it varies in the individual as between rest and exer cise. But for practical purposes here it may be assumed that the volume of blood and the volume of air brought to the lungs in one minute are approxi mately .equal. The blood, as I have stated before, not only -comes into gas eous equilibrium with the air in the lungs but, as it continues its round, it comes into gaseous equilibrium with the tissues of the body. The stream of blood thus acts as a medium of transportation of volatile substances from the lungs to the tissues and from the tissues to the lungs. Volatile substances can reach the tissues or'leave the tissues no faster than they can be carried in the blood. Third: in this system which I describe, is a regulated volume of air reaching the lungs. This volume--which I shall henceforth call the volume of breathing--varies with the activities of the man; when he walks slowly the volume is approximately double that at rest and when he walks vigor ously, approximately triple. We do not here need to put much emphasis on the fact that because breathing is reciprocal, only about two-thirds of the air breathed actually reaches the lungs. The last third of inspiration and the first third of expiration represent air that has been only in the upper respiratory passages and bronchial tubes. Next, with these three fundamental facts of respiratory physiology in 87 mind, I turn to those specific features which concern the absorption of volatile solvents which contaminate the air. The first of these is solubility-how soluble is the solvent in blood? This'is a highly important feature in determining the rate at which it will be absorbed and eliminated, and also a determining factor in some of the peculiarities of absorption and elimina tion and of allowable concentrations. Now what I have in mind by solubility is this--and this is the way we determine it: some of the solvent is evaporated into air just as it would be evaporated if it were exposed in an industrial occupation; a measured quan tity of air containing a known amount of volatilized solvent is brought in contact in a suitable apparatus with blood held at body temperature. The sol vent dissolves in the blood just as it would if this contaminated air were breathed into the lungs. Eventually an equilibrium is reached between the blood and air; the amount of solvent in each unit^redume of air and blood is then determined. The ratio between these amoutite-is what 1 call its solu bility; the solubility tells what proportion of the solvent in the air will pass into the blood when the contaminated, air is breathed. The solubility of sol vents varies enormously: thus for .alcohol, a highly'soluble solvent, the rela tion is 1 in the air to 1,300 in the blood--the blood will take uy 1,3CQ times as much as that in an equal volume of air. Such a high solubility means that virtually all the solvent will be absorbed into the blood as rapidly as it is brought to the lungs. Toward the other extreme in solvents is ether; the ratio here is 1:15--the blood will take up only 15 times as much as that in as equal volume of air. With this low solubility the solvent will be absorbed into the blood comparatively slowly. Using these two substances with their different solubilities I come to the next two features in absorption--the concentration in the air and volume of air breathed. Concentration in the air--air contamination by the solvent --can be expressed by many convenient terms, the values of which can be converted one to the other: per cent, parts per thousand; per ten thousand, and per million, and also by weight, as milligrams per liter. This last is not much used but I shall employ it here simply because it is more conven ient for my purposes. Purely for purposes of exposition we shall assume that we deal with two men and two atmospheric contaminations. The air in one instance contains 2 mg. per liter of alcohol vapor; and in the other, 2 mg. per liter of ether vapor. These are the concentrations--the expression of the extent to which the air is contaminated by these solvents. We shall assume next that the men exposed to these contaminated atmospheres each breathes 10 liters of air per minute. Ten liters of air with the concentrations given will hold 20 mg. of alcohol or 20 mg. of ether. These are the amounts of the solvents brought to the lungs in 1 minute at these concentrations. Now notice, if you will, the influence of change in concentration and in breathing on the amounts brought for absorption. If the same volume is maintained but the concentration is doubled or halved, the amounts brought to the lungs are correspondingly doubled or halved; likewise, if breathing is doubled the amounts brought to the lungs at any concentration are doubled. And notice further, if you will, that it is the volume of breathing which at any concen tration is the limiting factor to the amount brought for absorption--no more can be brought than is carried in the air breathed. Now I return to my original situation--10 liters of air breathed per min ute and 2 mg. per liter of the solvent in the air. Twenty milligrams of alcohol or 20 mg. of ether will be brought to the lungs in 1 minute. But how much 88 / S& will be absorbed? There is where solubility comes into play. With alcohol, the 20 mg. brought to the lungs in 1 minute will be distributed between approximately the same volume of blood and air in the ratio of 1:1,300. A little mathematics will show that under there conditions 1*0.33 per cent of the alcohol brought to the lungs will be absorbed. For ether, with its lower solubility of 1:15, only CO per cent will be absorbed. Thus if these conditions remained unchanged--which they do not, as 1 shall point out in a moment-- at the end of 1 hour the man breathing the air contaminated with alcohol would have absorbed into his body 1.19 gm.; and the man breathing ether only 0.72. Solubility, as well as the volume of breathing and concentration of the solvent in the air, is a primary factor in determining the rate at which a volatile solvent will be absorbed. With substances that arc very insoluble --far less so than the volatile solvents--such as nitrogen or helium, the volume of the blood flow is a more important feature than the volume of breathing in determining the rate of absorption. A moment ago, in comparing rates of absorption over a full hour, I made one reservation: I said that the rate of absorption would not continue at that established for the first minute of absorption. What I had in mind was the approach toward an equilibrium. And it is in this respect ti.at absorp tion through the lungs is markedly ditferent from absorption through any other channel. It has important practical corollaries. I return to my some what crude illustration, used in the first part of my talk, of the man drinking alcohol as compared to the man inhaling alcohol vapor. If he drinks the alcohol he continues to absorb it with no upper limit except that of such complete intoxication that lie can no longer drink. Such is not the situation when the vapor is inhaled; absorption stops here when an equilibrium is reached between the amount in the body and in the air. Let me illustrate this: the man who is breathing air containing alcohol vapor absorbs a certain amount during the first minute--the amount is determined by the concentra tion and the volume of breathing. The blood leaving the lungs passes through the tissues and shares with them its burden of alcohol. The blood returning to the Kings in the next round of the circulation carries back some alcohol; it can then consequently take up less alcohol from the air in the Jungs. As alcohol accumulate.' in the body, absorption becomes slower and slower and finally, after many hours, it ceases since an equilibrium is reached. The body is then saturated throughout with alcohol to an amount corresponding to the concentration inhaled. If you wish a figure for this, a little calculation supplies it. For a man weighing 154 pounds (70 kg.), equilibrium would be reached at the concentration which I have given for the air of 2 mg. per liter, when his body had absorbed 124 gm. of alcohol. He would then be fairly drunk. It would have taken him some 200 hours of exposure to reach this equilibrium with this highly soluble substance. In contrast, for ether, with its lower solubility, the total amount accumulated In his body at equilibrium would not be 121 gm. as for alcohol, but only 2.1 gm., and the equilibrium would be reached, not in 200 hours, but in 30 or less. Two and one-tenth grams of ether in the body would cause no appreciable HI effects. The man could thu breathe the concentration of ether given here for the air indefinitely without ill effects. No matter how long the exposure, no matter what his volume of breathing, he could never accumulate more than this amount if the concentration in the air rose no higher. These equilibrium values are the basis of permissible concentrations in industrial occupations for indefinite exposures. They vary with the solubility of the solvent and with the amount of the solvent that can be tolerated in the body without harm. For all concentrations in the air higher than those which can be inhaled 89 on o .vi J* i *; % \ 1 3 i 4 * -- ~ - i ... indefinitely, a tii.-.- limit of exposure must be placed. This time limit is established so that at the higher concentrations no more than the allowable amount will be absorbed into the body. If we assume--and it is merely an assumption--that, for ether, 2.1 gnu, the equilibrium value for a concentra tion of 2 mg. per liter of air, is the highest allowable amount and then we doubled the concentration with indefinite exposure, twice this amount would accumulate in the body--an undesirable condition. For the higher concentra tion we should then shorten the time--and it would necessarily be consider ably less than half the equilibrium time--for the permissible length of exposure. Following these principles it becomes possible to formulate practical re lations between concentration and time of exposure so that safe rules for industrial procedures may be established. There is just one final point to be covered. So far I have dealt only with the absorption of the solvents; I deal next briefly with their elimina tion. A few solvents--of which ethyl alcohol is one of'the rare examples-- are burned or otherwise altered chemically in the body. The remainder an? eliminated in the same lorm as that in which they are absorbed. A small portion passes out in the urine, but by far the greater portion passes out through the lungs in the expired air when the man ceases to breathe the contaminated atmosphere. The principles of elimination through the lungs are essentially the reverse of those of absorption through the lungs. There is, however, one marked di/Terence. A great many different concentrations in the air breathed and a great many different lengths of time could result in the absorption and accumulation of the same amount of solvent in the body. Thus a man might breathe ether vapor in the concentration that I have dealt with here. 2 mg. per liter, for SO hours and accumulate some 2.1 gm. But he could also accumulate this amount in 1 hour if, instead of 2 mg., there were about 7 mg. of ether vapor in the air. On the other hand, during elimination, barring variation in volume of breathing, it is the amount accumulated in the body which--quite indepen dent of any condition of absorption--determines the length of time for the particular solvent to leave the body. It would take just as long, and no longer, for the 2.1 gm. accumulated during SO hours to leave the body as that accumulated during 1 hour. It is occasionally a point of some importance that the length of time the solvent remains in the body, and therefore acts n the tissues, may be far greater during the period of elimination than dur ing the period of absorption. And now a very few words on the principles-of elimination. The hypo thetical man whom we have been discussing has absorbed a solvent and accumulated a certain amount in his body. He then goes into uncontam inated air. The solvent diffuses from his blood into the air of his lungs and, with exhalation, a portion is eliminated into the surrounding air. The blood leaving the lungs, having lost some of the dissolved solvent, contains less than the tissues; the solvent accumulated in the tissues then diffuses from the tissues to the blood. As the blood returns to the lungs, part of this sol vent passes to Iheair and is eliminated. This process continues at a pro gressively slower rate until all of the solvent is removed from the body. If the solvent is highly soluble it is eliminated very' slowly. There are few substances that leave the body more slowly than methyl alcohol, which has the high solubility of ethyl alcohol, but is not oxidized in the body. On the other hand, substances which are only slightly soluble leave the body' in a very' short time. Tims ether leaves much more rapidly than alcohol. DO * For a soluble volatile solvent the volume of breathing is a determining factor in rate of elimination; for one with only slight solubility, far less than that of ether, the volume of breathing has Utile influence* but volume of circulation a marked influcr.ee on rate of elimination. The explanation of this difference is in these facts: the volatile solvent which is highly soluble diffuses from the Mood slowly and only in proportion to the amount of air in which it can diffuse. Only a small portion leaves the blood during any round of the circulation and therefore* the rate of circulation makes little difference. For the substances of low solubility nearly all that is in the blood reaching the lungs diffuses at once into the air of the lungs--the limiting factor to rate of loss is the rate at which the blood brings the sol vent from the tissues to the lungs. J have given certain approximate values for rate of absorption of alco hol and ether, which I choose as typical solvents. Let me supply similar and equally approximate figures for the rates of elimmatibh.but substituting methyl for ethyl alcohol. I shall assume as before that 2.1 gm. of each sol vent has accumulated in the body. Nearly all of this amouht:0f ether would leave the body in less than a half hour; but more thah'6 hours would be required to get rid of *k- same u.ioi:nt of methyl alcohol. It is because of this slow elimination of highly soluble substances that they are spoken of as accumulative. If the man had absorbed sufficient methyl alcohol to pro duce any evident effects, he would not have got rid of it over night; with exposure the next day the concentration in his blood would rise and it would rise day by day with an accumulation up to the point of final equilibrium or serious injury to the man. In this resume I have tried to illustrate some of the basic principles involved in absorption and elimination of volatile solvents. And the points I have tried to stress particularly arc- those which have in their application some practical importance; the influence of solubility and of volume of breathing and the significance of equilibrium values and of concentrations. PROFESSOR DRINKER: Practically every firm today is interested directly or indirectly in contracts for materials for the government to be used in some phase of the re-armament program. Some of us do not under stand as fully as we should like the possible ramifications of the WalshHealey Act,'nor are we aware of the extent of the control which is possible for the government to apply in industrial hygiene directions. The government can be of the utmost assistance to us in this work, whose interest is in the maintenance of industrial health. I suggested the next speaker, Mr. Walling, as a man who is perhaps best posted to talk to us on this subject. I happen to have known him for some time myself and it is a special privilege and pleasure to me to be able to present him to you today. Mr. Walling. bt: FJv h THE IMPORTANCE OF THE WALSIMIEALKY PVttLlC CONTRACTS ACT AND ITS HEALTH REQUIREMENTS IN NATIONAL DEFENSE L. METCALFE WALLING* I have noticed in the program of almost every convention which is meet ing this Fall that the central theme of discussion revolves around the national defense program. In the threat of danger from abroad, of which all Americans are now aware, our entire thinking is colored by the problem of how to make ourselves impregnable before any attack comes. Industry, of course, as the source of supply for the physical materials necessary for total defense, against the now technique of total attack, has been in the midst of the now whirl of activity. The Air Hygiene Founda tion. which has played such an important part in the stimulation of better health conditions in the physical equipment of factories, will have an oppor tunity tc play an increasingly important role, not only in its usual field of encouraging health, work in the even more important field of sneerting up the whole defense program. I need not emphasize to this audience the importance of good physical conditions in plants as a means of keeping production up to the level required. As a matter of fact, I suppose we all agree that the present level of production will prove inadequate in the months to come to meet the neces sities of the situation and, if the additional strain on our present resources and industrial output is not going to cause an actual decrease in efficiency and in total output, we must take the steps which you and I know are so necessary to cut down occupational illness and the appalling toll of accidents which cause wastage, damage to machinery and a general slowing down of production. During normal tin.es, if the times we have been having In the last ten years can be designated by so polite a term, the nation can perhaps 3tTord the luxury of 10,000 industrial deaths and a million and a half disabling accidents a year as we had in 1939, but certainly under the stress of a pre paredness economy we can not permit the loss of efficiency and the slowing up of potential production which these figures indicate. The impetus of the defense program has once more focused attention forcibly on the standards which are required of industry by the Government in supplying it with its necessary material. Many people have become so accustomed to the Walsh-IIenloy Public Contracts Act after its four years of operation that they have almost forgotten, about its provisions. Most of American industry is now operating on a 40-hour week with time and or.ehalf for overtime beyond that point as now required of interstate industries under the Fair Labor Standards Act. This, of course, has been the provision of the Walsh-Healey Act for more than four years and has affected a large part of American industry which has been contracting with the Government in amounts of over $10,000. and I suspect that this is one of the reasons why the general adoption by industry of the 40-hour week caused so little flurry and necessitated so little readjustment. In this period of time over 30.000 contracts valued at about S3.000.000.000 have been awarded subject to the labor stipulations required by the Act. These include the S-hour day ar.d 40-hour week with unlimited overtime at Administrator, revision of Piddle Contracts. U. P. Department 'f l,ah.-r. 02 01 o **** ' ' t,-:- , I. time and one-half; the payment of minimum wages determined industry by' industry by the Department of Labor in accordance with the prevailing scales--about 2,000,000 workers in 54 industries have felt the benefit of the minimum wages required in contracts; the prohibition of child labor and of convict labor--incidentally so far no convict labor has been employed on a government contract and very few children; and finally the performance of the contract under safe and sanitary working conditions. This last is the requirement which most interests you as it is the only requirement in Federal law which affects the actual physical conditions of work. The Wage and Hour law deals only with hours, wages and child labor, and no matter how high a company's standards may be in this field it can have the worst health and safety record in the country and still be in compliance with the Fair Labor Standards Act.. As you know, a great many, pc-rhayfs most of the States have very little legislation with regard to health and safety matters in, in&ustry. Although under tlie terms of the Public Contracts Act'-'the :stahdaVd of;tho State where the government contractor is operating is prima facie thesiandard of com pliance by the contractor with the health and.safety,.jrt'O^^Ons of the Act, only one-thircl of all the States are in a position !? advise us about the phys ical conditions of work in plants receiving government contracts. If private* industry 25 years ago, under the stimulus of the workmen's compensation acts, which opened its eyes to the wastage of production through industrial deaths and accidents, had not taken steps to make its workers safety conscious and to provide good physical working conditions, the safety record of the country would not be what it is today. Some of the States have the power to adopt safety codes along recognized standards which have been worked out by industrial safety experts but many of them have no such power, and the number of States which have r.o jurisdiction whatsoever over the physical plant conditions is far too large. For these reasons, among others, the health and safety requirements under the WalshHealey Act assume tremendous importance at the present time. Although few people were thinking in terms of an industrial prepared ness program four years ago when the Act became law, it was a happy foresight which led to the inclusion of the requirement that articles sup plied the Government will not be "manufactured or fabricated in any plants, factories, buildings, or surroundings or under working conditions which are unsanitary or hazardous or dangerous to the health and safety of employees." As I have indicated, contractors are required at least to comply with . the standards of the State in which they operate but naturally where these standards were inadequate or non-existent we have had to adopt the standards which are generally recognized by industry'as -reasonable requirements. Frankly, until rather recently health and safety conditions have not been important problems in the administration of the Act. Many of the com panies dealing with the Federal Government .are leaders in their field, not merely in the product which they sell but also in the maintenance of good working conditions in making it. Our typical factory inspector who visits the contractor's place of busi ness is not a trained professional safety expert nor an industrial hygienist. He must be somewhat a Jack-of-all-trades. as he has in the first place to be an ambassador of good will capable of discussing with the employer his problems under the Act and making him realize that it is for his own pro tection against the destructive competitive practice of other employers as well ns for that of the worker. He must be familiar with payroll procedure . < / J '%i } 1 .3 1 t i 4 and be able to determine whether the minimum wages required or the* neces sary overtime are being paid. If he suspects, as unfortunately we have found reason to do in a small number of cases, that the records have been falsified to cover up violations, or if he limbs the records so inadequately kept that it is impossible to determine whether the Act lias been violated, he must be able to talk with employees and gain their confidence so they will tell him frankly without fear of the loss of their jobs whether their employer has been complying with the requirements of the Act. We have had several safety schools as a part of the in-training program of our field men, but obviously the training which can be given in this way is cursory compared with the wealth of information and experience which the professional industrial and safety man in the best establishments is able to accumulate over a period of years. Wo have had, therefore, to limit our selves to the correction of the most obvious hazardous conditions, such as: fire hazards; unguarded moving parts of machinery; lack of remote controls to enable shutting off machinery at a spot away fromthe scene of the acci dent; lack of guards on exposed electrical equipment or lack of proper insu lation; lack of safety H-*hing and equipment; poor ventilation allowing dust, fumes, gases and vapors to collect; poor housekeeping with blocked exits, improper lighting, accumulation of waste materials and moisture; disrejiair of buildings, with holes in the floors and lack of guards on ele vators and elevator openings; disorderly stacking of material in stockrooms; lack of first aid facilities; and so forth. Of course in four years* time--and it must be remembered that many of our field men have had considerable industrial experience before becoming investigators under the Public Contracts Act--considerable experience is acquired from the mere doing of the job; and our men, therefore, can make intelligent suggestions to management for eliminating some of the more obvious hazards. In some cases where the problem was complicated and technical, management has asked for suggestions ami in such cases we have been glad to refer the problem to recognized health or safety experts in the Division of Labor Standards of this Department, which has been able* to offer practical advice. If there is a State standard applicable, we, of course, require in the first instance that it be complied with and ascertain from the State Depart ment of Labor what its record of the company in question is or, if possible, find out directly by observing the certificate of inspection left by.the State Department of Labor representative. In any case we advise the State of f unsanitary or hazardous conditions which are found so that whatever action is appropriate and just can be taken by the State.'and in every case an order Is issued to the company that the changes recommended be made as soon as practicable. I am glad to be able to say to you that in no case so far has an industrial establishment raised a question as to the reasonableness of the order issued suggesting corrective measures. In view of the importance which you and I know good working condi tions bear on efficiency of production every effort must be made from now on to encourage better physical working conditions. I need hardly remind you of the situation during the last war, which threatened to become ser ious, where production slowed down because of the long hours of work which were required in certain industries under poor working conditions, although in many cases we did not have enough knowledge then to realize that the conditions were not only had from the standpoint of health and safety of the worker but also were incificient from the productive standpoint. We did not 94 Jf / i\ realise then as \vo do now how poor lighting and bad ventilation produce fatigue which slows down production, it was put until we were well under way in the war in 1917 that we realized that Jong hours actually decreased production instead of increasing it, as we had always .supposed. The situa tion assumed such proportions that in 1017 the Chief of Ordnance of the Army issued a statement urging industry to keep its hours of work as short as possible in order to get the utmost etliciency from the available manpower. As many of you know perhaps, only recently the British Factory Acts, which correspond to our hour ami wage legislation, had to be reinstated after a temporary abandonment of them, as it was fouud that production decreased so seriously, There was no question of sabotage involved but a sheer inability to turn out as much work during the longer work week as was possible under the old standards! It is of the utmost significance that A nation like Britain, which has been backed into a edrher and is fighting a desperate battle for survival, has found as a result of sheer necessity that the World War experience is being repeated and that short hours, decent wages, and good working conditions are the first line of .defense in industry. Fortunately, recognition of the importance of these things hs uv-ady been given in this country and the Secretary of Labor lias appointed a National Committee on the Conservation of Manpower in Defense Indus* tries, composed of 24 members who are concerned in the problem of good physical working conditions. The country has been divided into 8 regions under the general direction of volunteer safety experts from private indus try who have generously donated their services in an attempt to make the defense industries more health and safety conscious. They have assembled local committees of volunteer exports whose services are available on a free basis to assist particular companies which have not yet done very much in the safety field in setting up programs. Although the Walsh-Healey Act has plenty of teeth in it, if it is neces sary to use them, we arc not using coercion to bring about the desired result. I am sending a letter to every company which has a defense contract advis ing it of the free and expert service which is available to it in giving assist ance in a program to lessen its accident and death rates. We must remem ber that the Government is now dealing with many new and small companies which have not been in the government market before but who are being consciously drawn in by the Government through its policy of negotiating contracts directly as well as by competitive bidding to provide as many sources of supply as possible. Large appropriations have been made to the War Department for edu cational orders, which are placed for the very purpose of enabling companies ' which have hitherto not dealt with the Government to become experienced In making the kind of supplies which the Government is now buying and which it desperately may need in the event of an even .more serious emer gency than the one in the midst of which we now are. Many of these com panies are not safety conscious. Many of them have no health and safety program and, of course, no safety expert whose job is to watch like a hawk the industrial accident and death figures. It is earnestly to be hoped that this opportunity of receiving free assist ance from men who are experienced and recognized experts in the safety field will cut down hazardous working conditions in many establishments which are now giving little thought to them. It is essential that this be done if production is to be continued at the level which the nation has a right to expect from the superb industrial equipment which it has. 95 0lx9 o rr We arc dealing with ail kiwis of companies, from the mill which one of our investigators recently reported to me whore the drinking water supply was purposely kept so tepid that the employees would not drink it and were induced to purchase* Coca Colas sold by the company for a small profit, to large companies with all the most modern safety equipment with a personnel aroused to the importance of keeping accidents to a minimum awl with almost perfect safety records. It is fortunate that we have the machinery already functioning to handle the many industrial problems involved in the sudden incidence of govern ment buying on all industry. You might he interested to know tjiat in July, August and September of this year contracts valued at almost the amount involved in the first two years of operation of the Act were reported to our office and in one week we had contracts valued at almost half what we had the entire first year of our activities. This is growing by leaps and bounds. It is estimated that of the S10,000,000,000 already appropriated for defense purposes, about fwm and a half million manhours of labor wiii oe created, of which nearly two-thirds will be skilled or semiskilled workers and only one-third unskilled. Four hundred thousand men received employ ment in manufacturing industry alone in August of this year, which is the largest employment increase for any August on record. Apprentices are being trained on all sides to fill the skilled jobs that are opening up. Many skilled workers who had become "rusty" during the thirties by having run hot dog stands or clerked in drug stores are finding their way back to their old jobs as tool makers. Hordes of young people who have never worked in industry before are finding their way to profitable employment. All of this raise? new problems to be faced. The influx of this large body of new workers who have not had previous experience in industry, who are not familiar with machinery, and who haven't yet developed the "feel" of the factory is going irevftahly to raise the accident rate as it did during the last war. We know from the accident figures that the incidence is higher in this group because of their immaturity and carelessness. Certain other problems which arose suddenly ir. 11*17 and had to be dealt with by setting up temporary machinery fortunately will not plague us now. There will not he the disastrous competition between industries and between the industries and the Government which wad characteristic in the last war, as there will be uniform labor standards which will tend to iron out the r advantages to be pained by shopping around from place to place to get the best job. The Government will thus be assured of continuous sources of sup ply in vital industries and will be able to buy for fair prices kept in line by the stability and continuity of the labor supply. No machinery wns in existence to handle such matters or to deal with industrial disputes during the last war. I think we are fortunate in having such machinery which has been smoothly operating for four years, and to which both industry and labor have become accustomed. We now have a nationwide free public Employment Service where the job seeker and the job giver can get together. We had to set up such an employment exchange hastily during the last World War in an attempt to fill the sudden needs for workers that developed. I think 1 can safely predict that the more general recognition of the wage earner's fundamental rights will minimize industrial disputes and that we will not have the record of strikes which we had in the last war. At any rate the record to date certainly justifies this optimism. - 96 X * i \ ** ... ^ 4. --'ir-'-WV .. In the final analysis, however, all those things depend not on the sanc tion of law hut on the inherent desire of the American people to pull together in the national objective. In the particular field of health and safety, we can legislate until the cows come home hut until we really arouse industry and labor to a consciousness of the importance of being awake 2-1 hour* a clay to the need of constant improvement of the physical conditions of work we shall have accomplished only a small part c-f the task before us. I know only too well how frequently employees arc reluctant to use the safety devices which arc supplied them. Goggles and respirators are nuisances and safety devices sometimes slow up production so that earnings on piece rates are lower. One of your main problems is not only to install tho best safety devices but to see that they are used and to make your men health and safety conscious. After all. the largest number of accidents are still of the slip-stumble-fall variety. Even if there is not grease on the floor the worker who is careless may fall and injure himself. I think we have a real opportunity out of this emergency to make the nation health and safetv conscious and to improve the-physical conditions of work in a wav which will have lasting benefits and pay dividends to industry as well as labor. In any event, in this emergency production must not be curtailed by the inefficiency of lost time through sickness, accident, occupational disease and death. We must have less than 16,000 deaths and a million and a half disablements during the coming year. It will be difficult not to exceed this figure because of the greater pressure under which we will be operating ar.d the untrained personnel with whom we will be dealing, but this should only be a challenge to us to increase our efforts. I hope and expect that it will r.ot be necessary to use the teeth in the provisions of the Walsh-IIealey Act requiring good physical conditions in the coming year any more than it has been in the last four, but the teeth are there if they have to be used and the results must be achieved. The Government must get its supplies on time and that is why we are doing everything that we can to promote the factors which we know will make efficient and speedy production possible. The Air Hygiene Foundation can make no more helpful contribution to the national welfare and the defense program than by continuing its intelli gent and vigorous efforts to encourage better health conditions in American industry. PROFESSOR DRINKER: Mr. Walling told me that he will welcome discussion of his paper and holds himself in readiness to answer questions. I should like to ask if the government has any position with respect to the Walsh-Healey Act with regard to physical examination of new employ ees, or are you just watching that? It is dynamite, isn't it? MR. WALLING: We haven't taken any position. As a matter of fact, I doubt very much if we will. That is a matter somewhat remotely con nected with the obligations of the employer under the Act and it is so defi nitely tied up with workmen's compensation matters, for instance, which are of course the subject of state legislation and not federal, that I think we would not make any requirement one way or the other about physical condi tions of workers. I read you the very general provisions of the Act pur posely to show you how general they were and the fact that it is necessary in ever>* case to implement them. I think in this case it is better to make haste slowly and not attempt to lay down too precise rules until we are more 97 oa o i .. ,-,-rrr lifTWii,Ti-,,a, Tf iifcn i'ii'i'1 1 i 4 / **'* sure of the legitimacy anil reasonableness of the requirements that can as a practical matter be carried out. There is bound to be n tendency to use this legislation to achieve the millemum overnight, and while I am in favor of milleniums--I suppose we all are--1 think we have to recognize that it takes more than one night to Achieve it. I don't think we should try too much. I don't think >ve should bite off more than we can chew. . I think we should recognize our own limita tions in the field. We have thousands and thousands of factories all over the country, so that we cannot cut the brushes too fine to make the sweeping. For those reasons and many others I think we will not attempt to lay down any standard? about physical examinations, one way or the other-- aside from the fact, as you suggested, that it is dynamite. MR. AHEARK: Mr. Walling referred to the fact titli^only a few states, comparatively speaking, have satisfactory safety and- health standards. What is the government going to do with respect to those^Staies where there are no satisfactory standards? Will you write thoser-st&bdavds? Will you make them familiar to th<* contracting companies as well as tne sub-con tracting companies prior to the inauguration of the contract? MR. WALLIXG: That is something to which we are giving some con sideration now. Our system is this. In the case of about sixteen states we have regular and periodic reports of the office records which they have about factories within their jurisdiction, so that we know something about what the physical conditions are. In other states the state factory inspector may stamp the inspector's card indicating that he has been there and has approved the standard. But even in those cases we don't always accept that standard. I am thinking of one state where we found extremely hazardous condi tions from every standpoint--from the standpoint of occupational disease, from the standpoint of bad housekeeping, front the standpoint of a firetrap-- from the standpoint of almost every one of the classical things not to do that you can imagine. We politely called the matter to the attention of the state, and they equally politely replied that they had sent an investigator there and as far as they could see everything was lovely. Conditions were in com plete compliance. In that case we had to go ahead and say, "Even though you have been certified by your state as meeting the state standard, we don't consider it sufficiently high to meet the standards of the Walsh-Hoaley Act." In that case we issued specific instructions in detail of the measures which should be taken to correct those hazards. As I have indicated, we have been doing this somewhat on a hit or miss basis. AVe merely have been trying to correct the most obvious and most dangerous things. How much farther we can go is a question, with the limi tations of personnel and the increased load of work which all this program means. Certainly I think we should give serious consideration to the adop tion of standards which are pretty generally recognized by industry. After all, we have 8 considerable body of industrial law on the subject. There are standards which everybody would recognize to be reasonable, which we can use and adopt and perhaps even specifically make a part of the contract form which is signed, so that the company that makes the contract will know that A. B and C. by way of physical conditions, must be complied with If they are to perform the contract satisfactorily. That is somewhat in the future, Mr. Abeam. MR. BAILEY: What is the attitude of labor in general on the applica tion of this act ? OS o: JW MR. WALLING: Of the Wnlsh-llealcy Act? MR. BAILEY: Yes. Arc you getting a good response from labor? MR. WALLING: Wc have had a surprisingly small number of com plaints from labor about its violation, if that is what you mean. MU. BAILEY: Yes. MR. WALLING: I think that is partly due to the fact that very fre quently the employees in a factory do not know that they arc working on a government contract and do not know what the requirements are, in spite of the fact that by one of the provisions in the contract a labor poster setting forth the labor provisions is required to be posted. We have made a drive to get those posted during the time performance of the contract is being car ried out, but frequently the period is`rather short and the contract may actually be over with before the poster arrives. The'; employee doesn't always know' that he is working on a contract and what hls rights are. The small number of complaints is no indication, however, of the number of violations, which have greatly exceeded the number of complaints. In general I tnink that labor believes that the standards of the Act are reasonable standards, standards which ought to be retained. Certainly I am very conscious of the fact that labor is watching that these standards be preserved, particularly in the defense program, where there is of course great pressure in some places to skip over them. We have had a decided in crease in complaints which have been filed with us, which I think stems directly from the large number of new companies which have come into the government market, which I referred to earlier. I don't know that the num ber of complaints which are valid, that is, which actually point out violations, has increased, but the volume of those filed certainly has increased in the last few months. I might say also that wc have only begun to feel the increase in the program. To be sure, we had in the first three months of this fiscal year, that is, July, August and September, contracts valued at about the same amount that we had in the first two years of operation of the Act. That is as many hundreds of millions of dollars in three months as we had in the first two years. As a matter of fact, in one week we had about half as much as we had during that sanm period. In spite of that very large figure, I am sure we are not getting the full impact of the reports, because the Army and Navy clerical offices are so swamped with the inquiries that they have had that they are not able to report the contracts to us promptly. I assume that you all know that we hare nothing to do with the making of the contracts, except to require that these stipulations be included as a part of them. The particular contracting officer of the government, whether it be the Army. Navy, or the Department of the Interior or what not, actually makes the contract and then sends the report to' us in the Depart ment of Labor, so that it can be enforced and administered from that time on. MR. JOHNSON: I should like to ask Mr. Walling if in the case of states which have no labor standards now he would dare estimate that the regula tions to be imposed by the Department of Labor would not exceed the stand ards embodied in the American Standard Safety Codes now in more or less general use. MR. WALLING: I think we would go very slowly in exceeding those standards, if that is what you mean. Those standards, I should say, were 99 pretty generally recognized as what it is possible for industry to reach toward at the present time. We must remember that any standards which we adopt of a general, nation-wide nature must take into consideration not only the most progressive states with the highest standards but they must not be too impossible of attainment by industrial establishments in states which have had practically no standard or absolutely no standard at all. That is one of the difficulties of nation-wide regulation. MU. JOHNSON: By the same token, might it not be likely that your requirements would not come up anywhere near to the standards of the A. S. S. code? MR. WALLING: I think if they wefre nation-wide on!y, that would prob ably be true. However, on the* basis upon which we havic^bpen operating up to the present time we have, of course, taken into consideration in the states where the standard is best what that standard is and jWb have required that without any question. We feel that all industriid'est^lishments within the same state, whether they are competitors in the samo lino of or not, should be held to the same physical standards. It may not be possible or fair to hold industrial establishments, even though they are competitors perhaps, in a state which has not had any standards at all to that high standard. That is one of the difficulties with a nation-wide code at the present time, where there is such divergence of establishment of it and following of it. That is one of the reasons we think perhaps the absence of too specific regulations, as far as safety is concerned, may be a more satisfactory approach to the problem, unless we can go into it in a very thorough way and attempt to bring about the millenium. MR. BAILEY: I intended to go a little further on my question than I implied. We have heard repeatedly of the greater amount of lost time due to non-industrial causes than industrial causes. I wonder if this may not be a means of bringing that forcibly to the attention of labor itself. The non-industrial, rather than the industrial, loss of time is a contributing and really a major problem. Has anything been done on that? MR. WALLING: Just what do you mean by "non-industrial*'? MR. BAILEY: Sickness and non-industrial accidents and all of that kind of thing, which causes loss of working time. Wo have heard at our meetings repeatedly that that loss is so much greater. Qnc speaker said it was fifteen times as great, another four times as great, and so- on. We al! know that non-industrial causes result in much greater loss of working time than in dustrial causes. I am wondering if that matter, through this organization, can not be brought to the attention of labor, so that you will get better cooperation in that regard. MR. WALLING: Another division in the Department of Labor, of course, has the matter of industrial standards as one of its main functions, and it is doing what you might call propaganda or educational work in that whole field. I don*: think it would he practicable or desirable, as a matter of patting into effect a standard of law under the Walsh-Healey Act, to attempt to engage in a health program and a safety program to cut down sickness and disease outside industry, as a part of the obligation of a con tractor In the performance of his contract with the government. After all. 100 3 '------------ our jurisdiction in the administration of the Public Contracts Act begins and ends with the performance and completion of the contract, and we cer tainly haven't the time, nor do I think it would be wise for us, to extend our activities beyond these points and attempt to engage in a nation-wide health campaign. There are other agencies of the government and other agencies of industry itself which are concerning themselves with that problem. I think certainly we wouldn't put ourselves into the midst of that situation. MR. ISAILEY: I wasn't suggesting that it could be done by law, of course, but I was wondering if there couldn't be, in connection with this, some educational or instructive work to call attention of labor to it or to stimulate the activity of the other departments that have that in charge. MR. WALLING: I see Dr. Snycrfe of the Public Health Service here and I know he will be able to give you a very stimulating lecture on what the United States Public Health Service is doing along those lines for the gen eral health of the workers and people of the nation., PROFESSOR DRINKER: We are all concerned with the protection of civilians in wartime. Many of us have seen the recent movie of London Can Take It." If you have not, I urge you strongly to do so. We don't like to visualize such things for ourselves, but it will be folly not to prepare for them. We have asked Mr. Yant if he would accept an assignment along those directions of describing civilian protection. Since he has been interested in gas masks and the like since the previous war and has done much on it himself, it is fortunate for us to have him as a member of our own Founda tion family to talk to us. 101 * o a o o PROTECTION OF CIVILIANS IN WAR W. P. YANT* When the Air Hygiene Foundation of America invited me to-talk on the subject of Protection of Civilians in War, I accepted with some 1Hesitancy because it is the policy of our company to take no part in creating any hysteria relating to war. We know how to make war gas masks and other protective equipment, and if the time conics when our facilities are needed, our company will meet its responsibilities. However, through our industrial work and our contacts in this country and abroad we have gained some information on the subject which I am pleased to discuss briefly in an informal manner and largely from a personal viewpoint, because it is a matter in which every person that is here today should Tie tfoncerned. The course of international events might easily indicate that wc-ato already late in becoming informed and in making plans and preparation's; There are two ways in which we may protect our^civilians and civilian interests, which broadly ii.Juuc* the lives, homes and industries vf ui country: one is to keep out of war, and the other is to keep our civilian interests away from injurious contact with the implements of warfare either through impenetrable military defense or by movement to safe locations. The first way is almost passed. The second way is very difficult to attain, because today it is possible to fl\ from England to Italy, drop bombs and return. There are rumors that airships will soon be available that can stay in the air long enough to fly to Japan and return. It is apparent today that all persons whose nations arc at war are subject to the implements of war. Times have passed when* a person is safe if he is away from the range of bullets or guns. Now it is a matter of hundreds of miles--in fact the entire earth becomes the battlefield. Accordingly, if a nation is at war, the protection of its home interests must be considered not from the viewpoint of complete defense, but from the viewpoint of minimizing and controlling injury and damage. The suc ceeding discussion will deal briefly with some of the common implements of warfare to which civilians may be exposed, and with some of the things that have been done abroad to protect civilians and property. The implement of warfare that is usually thought of first in connec tion with civilian protection, is gas. Gas has not been used in the present war but it can and undoubtedly will be used any time that it will give mili tary advantage, whether this be for offense, for defense, or for harassing and destroying civilians. War gases are classified generally according to their predominating effects, as lung irritants, nose irritants, eye irritants, and vesicants or blister gases. Some are gases or vapors, others are smokes. They may also be classified on the basis of their persistency in remaining in the area gassed. Chlorine or phosgene, for example, are non-persistent because they disperse in vhe air and are carried by the air currents. When the contaminated air becomes diluted or is carried away by the wind, the area is immediately habitable. Mustard gas is a persistent type. It is a liquid material that evaporates slowly and will persist for days or weeks in the area and on objects with which persons come into direct contact, thereby making the area uninhabitable unless decontamination procedures are effected. Director of Research and Development. Mine Safety Appliance* Company. 102 n 0 /v V 0 L % / The implements to which civilians have bctn exposed the most hi the present war are high explosive and incendiary bombs. A high explosive bomh may range in size from 50 pounds to a ton or perhaps larger. From these there are hazards from percussion waves or shock, from splinters and fragments of the bombs themselves, from flying debris, stones and bricks, and from falling walls, chimneys, and other' structures. The incen diary bomb is designed to start fires. They are in general similar in design to high explosive bombs but are filled with substances such as phosphorus, thermite or other common pyrotechnic material which on ignition will burn rapidly to produce an intensely hot mass. Incendiary bombs arc usually much smaller in size than high explosive bombs, ranging in weight from two to 50 pounds so that an aeroplane- can^arry matiyvof them at one time. Some ignite immediately on impact! othc-r^re .^^^a^trating type with a delay in ignition so that they can be^ and then ignite the interior of buildings.'' for example, It is apparent that gas bombs^lvigh e^l<&ive^^mbs, or incendiary bombs might be used alone or might;beJ|?ed;-to^|ft^^pFor example, blister gas (mustard gas) bcrr.',,j may be used witli high cxploiive and in:./.diaries, in order to make rescue and fires more difficult to deal with or decontamina tion more difficult to carry on. In addition to hazards from gas, high explosive and incendiary bombs carried by aeroplanes or shells from long range guns, there is strafing and machine gunning of civilians by aeroplanes together with many other direct and indirect hazards and discomforts. Very important among these is the disruption of essentia] commodity and community services such as water, gas, electricity, and food supplies. Other influences arc the loss of sleep, fatigue, noise, exposure to cold, sanitation, crowding, and contagious diseases. The foregoing discussion is too brief to be complete but will serve to Indicate the many problems to be dealt'with in civilian protection. Fortu nately, some of the problems have already been given consideration, and much experience is !>emg acquired abroad in others. Gas masks for protection from war gases are in general similar to industrial gas masks, with which many of you are familiar. The canister must contain sorbents that will take out acid gases, such as phosgene and chlorine, and vapors such as mustard gases and blister gases, and also a very efficient filter for removing the irritating smokes. As the concentra tions ofwargases and smokes encountered are in general very much lower than the concentration of industrial gases that are frequently found in industry,: it is not difficult to make a mask for protection of civilians. Every country at war today has considered the need^sf such protection and the principal countries have issued masks to their civilians. In addition to needing masks for respiratory protection from gases, special clothing is needed by special sendee personnel such as firemen and others who may be required to remain in areas infested with blister gas or similar gases, for duties such as decontamination work, fire fighting, and making utility repairs. These persons must be completely protected, in other words, no skin part can be exposed. Fabrics that are either impervious to the gas or are impregnated with substances that will take out the gas are available for clothing of this nature. Shelters of various kinds are used widely for civilian protection. Many of these shelters are essentially barricades made from boxes or bags filled with sand, or trenches and dugouts, for protection from bombs or machine gunfire. If gas protection is required, cither the civilian gas mask is used 105 or some means of tens prolection is incorporated in the design of the shelter. The simplest form of gas shelter u--cd is merely n room of the home that has been made practically gas tight by scaling cracks anti openings with tape. A more elaborate design consists of an underground bomb-proof space of concrete or masonry with either gas tight doors or with ventilation facilities that will remove war gases and smokes. This type is either con structed according to plans suggested by the Government or is available commercially in sizes ranging from family to large groups. Use has also been made of exi.-ling underground structures such as subways and tunnels. / i> I .'1 i . Considerable work has been done on ventilation requirements and equipment. It is apparent that the factors of consideration are the oxygen consumed and the carbon dioxide liberated by respiration, and the heat and water vapor given oft by the person to his surrounding environment. The simplest form of a shelter is an air tight spaeowithoufc ventilation or puri fiers of any kind. Obviously a room of this; nature-would have to be large enough so that livable conditions are maintained for. a^r^tsonable period of occupancy, say six hours. By building the shelter underground advan tage is taken of the cooling effect of the earth, the -temperature being approximately Go degrees Fahrenheit. Under these conditions, it has been established that 75 Square feet of wall space\per peisdhfis featisfacr''**y <or six hours; while 100 square feet per person is satisfactory for 12 hours. When effective ventilation and air purification is employed, the size of the space can be reduced to the minimum required for a person to occupy, approximately 6 square feet of floor space. It would appear, however, that a person would be a little cramped in the designated minimum space if he had to stay very long. In constructing an underground shelter, con sideration should always be given to materials with poor heat insulation values--in other words, good conductivity, like masonry or concrete blocks. Room equipment seems to be a very important thing and is stressed everywhere. - The necessities of life must be provided: food and water, pro vision for sanitation and hygiene, protective devices, first aid materials, fire extinguishing equipment, repair materials for the room, and finally amuse ment and rest. Upkeep of morale is an important factor. Aside from the material aspects of civilian protection, a very important part is the organization. They began to form these organizations in Ger many as early as 1932 and 1033, and in England in 1035 and 1036. In their plans they considered what they should do at the present time (1035 and 1036), what they should do as opportunity affords, what they should do when emergency is imminent, when warning of danger is sounded, what they should do during the raid and after the raid is past. England has .passed through all of these stage? now. . It is .a fair question to ask, "in what stage are we?" **" It Is apparent that we are in the stage, at least, where we should be doing gome thinking, where we should be making definite plans, ar.d where the public should be better informed. This is not a matter for technologists alone. It is not a matter for a few people. It is a matter that affects every civilian who might come within the scone of warfare and it is a matter that must be handled largely by civilians. Why should we be any more immune than the civilians of our neighbor country north, where they are already making some plans? We perhaps have some, but they are not as generally known as I personally think they should be known. The organization in England for dealing with air raids and attacks on civilians is about the same set-up as that required for military operations. Vt 104 { 0 n Q fa U C \ "rrr if i *F~ --Tr~ / / ! ? : i In other words, they have facilities for the treatment of casualties, movable first aid unit*, first aid posts, casualty stations, base hospitals, ambulance service, laundry and decontamination services, and clerical and record ser vice. Jt is very important to keep records in situations whero there is panic, demoralization, people chased out of homes, and general scattering of m:h, women and children. After taking care of immediate casualties, there is the matter of rescue service, demolition service, decontamination service, lire fighting, gas detec tion, emergency communication, protection of civilians and employees, lighting restrictions, air raid warnings, and other things. This gives yuu an idea of the magnitude of the problem. As a key organization used in one country, they have a well organized home defense and home security branch. In a community the first important tjgent is the .local warden, lie is the man who knows all about his particular community assignment. lie is supposed to know all about the police department facilities,^rc fighting facilities, hospitals and where the doctors live, who the pepplc hre and which ones are aged, infirm and can't be moved; where thevgasdipts arc and how they can be shut off: whether there is a^thihgcpartieaUiiiy vulnerable in that district; and ?!> such things of importance. In other words, I'-' *>': key man that guid-.-i all of the work for that particular region. The warden is a selected man of good responsibility* and trained for his work. He has equipment for dealing with putting out fires, decontamina tion work and other necessary duties. He has at his command and call a number of other services. He has a rescue -service. That includes a motor ized squad equipped with jacks, torches, crowbars, and tools for recovering persons from debris, for demolishing buildings, and for tearing down walls that are hanging and creating additional hazards. There is a decontamination service. This consists of another squad which the warden cal is on to go out and decontaminate an area that is. infested with gas. The personnel have special training in anti-gas work. There is a gas detection squad that gives service and advice regarding whether gas has been used, what kind of gas, and what is to be done ab-'ut it. This is a trained technical service. In addition, there are other special ized sen'ices available on call. Protection of industrial workers and property is apparently handled to a large extent by the industries themselves, but through the general regulations that have been put ont for civilians. That is, industry organ izes its protection on the basis of the individual industry, somewhat the same as they organize in American industry for safety work or fire pro tection. Any work of this kind that reaches so broadly into the civilian popu lation requires much time and effort of an educational and training m-.ture t make an effective, functioning organization. Many publications and information sheets have been issued abroad and in language that civilians can read and understand. There are books on civilian gas detection, kinds of gases, kinds of shells, kinds of bombs and what they do, how deep a bomb will penetrate, how to construct shelters, first aid, lighting, protection of children, care of animals, food contamination, and practically every phase of civilian protection work. In this discussion I have endeavored merely to indicate some of the problems and answers relating to civilian protection. In this country there ore many available facilities that can be utilized. In New York and many other cities we have tunnels and subways. Here in Pittsburgh we have the 105 % .*1 0 &' i Liberty Tunnels, the Armstrong Tunnel, nml the old Wabash Railroad tunnel. Under Herron Hill and other places we have old mines that could be opened up. In Pittsburgh we are also fortunate in that the land is hilly. It is much easier to build a bomb shelter on the side of a steep hill or cliff than on level ground. It is easier to get further underground and construct a pro tection roof and it is more difficult to attack with bombs and shells. It is hoped that we will never have to use these and other required facilities or to function as a nation in the capacity of actually protecting our civilian population and industry from the implements of warfare. However, it has become necessary for us to at least begin to think and plan. \ l / DR. SAVERS: What proportion of civilian masks dh you think should be provided? MK. YAXT: Of course in a country jlikc England amt-:more densely, populated places it is pretty high. I think'England made something on the order of thirty million, or r.tar'... enough for every person over thc-ie. .New, " I am not so much afraid of that. In fact, if I were out in the good open spaces around Iowa and Nebraska I think I would trust to my legs about as soon as a gas mask in a case of that kind. But where you don't have open spaces and where shells or bombs might be used to more advantage I think you should have masks. In densely populated districts, in cities and in places that might be in the path of invasion I think they should be sup plied. But out in the country I wouldn't worry much about it. I don't think they would waste any shells there to begin with. You could dodge them and get out of the gas cloud very easily if they did. I am not so sure that you can cause any widespread gassing even in a city. The main thing, of course, that can happen is to cause a panic among the people. One important thing the civilian gas mask does is to preserve morale and give a sense of security. In other words, they have`a psycho logical effect as well as a practical effect. If there are no other questions I will turn the meeting back to Dr. Meller. DR. MELLER: I want to thank all of those who have taken part in the two*day program, which I am sure the listeners have found most interesting and instructive. The meeting is adjourned and will be followed by a short business session. K r { i ( I l 106 0 X. t'o % J4L f\ .1 r *