Document YGRVaGMRJZj66QeEg5oaxB2wk

9< .i; 4 tfc**9*# vp* conc*m*9 ttrMt A0 IlMHtflK gyfff)r. To "C1 it til * liicUt. ** *4 K#r 'Por,J- 9*t*r witK ditort' ooo*tfc. Tht riiorl po`- 4CT u to *'* <rk OutwM On thi eort*tM*l,o*l` ** * "O c* n* ccw*c> c* ou tw* >* H ** #.f oo-r.ent o' c* i ft on >o* e* #.< v vi--<p> o>*o' .!..IP > '* e** *fc o* tt>p tp i*f lk. f r The Journal of Occupational Duetto and Trtumttic Su-gerv With which ere consolidated "The Industrial Doctor" end "International Journal rl Mcoicmc and Surecry." The Science, the Law and the Economics of Industrial Health Volume 9 FEBRUARY, 1940 Number 2 General Motors Corporation Medical Conference --Dayton, Ohio, Novnuhfr 2 mill 10JO-- THE recent Meukwi. Conference ok General Motors Physicians, held at the Biltmore Hotel, Dayton, Ohio, November 2 and 3,1939, comprised five meetings and 18 presentations. The Program was as follows: Thursday, November 2: MORNING Session: Chairman, 1.1, M. Shafer, M.D.. Medical Director, Frigid.nre Division. Dayton. 1. "Recent Developments in Relation to Silicosis." LeRoy U. Gardner. M.D.. Saranac Lake, New York. ;. "A Plan lor the Control of Tuberculosis in Industry." Max Buhnell. M.D.. Medical Director. AC Spark I'iug Division. Flint, Michigan. 3. "X-Ray in Industry," M. Willxajvi Cur:. M.D.. Hurley Hospital, Flint. Michigan. 4. "Preliminary Report on Hygiene Studies of Weld ing." L. B. Case and V. J. Castrop. Industrial Hygiene Laboratory. General Motors. Detroit. AFTERNOON Session: Chairman. A. L. Brooks. M.D.. Medical Director Fisher Body Division, Detrar,. j. "Rrccnl Developments in the Occupational D rni.i- toses," Marion 3. Sclzbehccr. M.D., New York City. 6. "The Course of Disabling Morbidity among Indus trial Workers. 1921-1938." William M. C.ArArEii. D.Sc.. L\ S. Public Health Service, Washington. C 7. "The Industrial Nurse." Harold M. James. M.D.. Medical Director. Delco Products Division, Dayton 8. "The Doctor s Part in the i'crsunucl Prugum." Georce A. Cosurk. Personnel Director. Delco-Remy Di\ .sion. Anderson, Indiana. EVENING Session: Chairman. Walter M. Simpson. M. D.. Director. Kettering Institute for Medical Re search. The Miami Valley Hospital. Dayton. 9. "Relationships of Industrial Medicine to Private practice," Stanley J. Seecer. M.D.. Chairman Council on Industrial Health. American Medical Association. 10. "Unfinished nusmess." C. F. KrrTniiNC. Dirreiur General.Motors Research Laboratories. Detroit. Friday, November 3: /rORNING Session: Chairman. G. L. Btnn. M.L.. Medi- IYI cal Director General Mi-lors ul Canada. Ltd.. Osita- a, Ontario, Canada. 11. "A Practical Approach to Supervision of Mental Health m Industry " F. S. Parney, M.D.. Chief. Division of Industrial Hygien Dvpt nf Pensions and National Health. Ottawa. On. g `van fcxamok - C nnda. :try's Participation in the Anti-Sy, Ctrnr............... : < -t. M.D.. Medical Du i ciu.. Fisiu-i HoCy Lansing Division. Laming. Mich.gan. 12 "Study of the Factors of Emnloyabiht.v. Espccialiv Disabilities and lnlirr...:,es of the Elderly, and Problems Arising from Employment of the Same," Gconcc A Paul. M.D.. Medical Director. Hyatt Bcnnncs Division. Harrison. Ni w Jersey. 14. "Early Diagnosis of Acute Appendicitis." Rusk McAdam. M.D.. Medieal Director. Fisher Body St. Llui* Division. St. Louis, Missouri. AFTERNOON Session- Chairman. F. B. V.'isii/.no M E . Medical Director. Delco-Remy Division. Ar.acrson. Indiana. 13 "Relationship of the Length of the Inguinal Liga ment to the Occurrence of Inguinal Hernia." C. M. Hillexeranb. M.D.. Medical Director. Harrison Radiator Div,sion, Lockport. New York. 16 "Hernia in Industry; Review of the Cases During the Paul Ten Years." R. L Joiinston. M.D., Medical Director. Inland Mfg Division. Dayton. 17. "Antiseptics and Their Action." R. M. Freeman. M.D.. Medical Director, Linden Division. Linden. New Jersey. 18. "Mnnaevment of Fractures of the Spine." R W PononsKY. M.D.. Medical Director. Electro-Motive I>iv,Mim. La Grange. Illinois. Except fur Dn. Sulzdercer's address on "Recent Developments in the Occupational Dermatoses" all of the papers given at this Conference are in cluded here in full text, in the order of their places on the Program: Recent Developments in Relation to Silicosis LeRoy U. Gardner. M.D.. Director. The Saranac Laboratory jor rite S:ucy oj Tuberculosis. Saranac Lake. Ketc York WHEN your Chairman asked me to speak of new developments in the field of silicosis I was perplexed because all but a few cf the pathological, clinical and diagnostic aspe of th:s disease are now well established. ! reakred Prgc 46 INDUSTRIAL MEDICINE Fertruc *4m ; A:' that you had become better acquainted than 1 with ill lltc btiiiiclin'lv' As 11 .*:i Uimiin .11,J y. the practical problems of diagnosis because you tract*, the air spares an obliterated b> scar were dealing with them every day. After sunie >ui. In expel mn. 1.tal animal:., .it icuM. this el.ai.ee deliberation I decided to tell you of some of the is nut a progressive unr afte: cessation of expo: .in experimental work in prepress at the Saranac to the dust as is the ease in the response to qua:'./. Laboratory and to permit myself to speculate as Perhaps the reason is the deposition of the |.- to its significance. These experiments are incom culiar iroii-enr.tanhng coaling on ti>e surf..ee ot plete and no conclusions are possible now. but the inhaled fibies giving rise to the charaeteust:. perhaps they may ultimately lead to a better un- "asbeslosi> hoiiics*' Dr Timothy I.ear\ mrsi.i. cicrslanding of the action "1 irritant dusts upon er.v` that the resultant Mnoolii nuu.ucii enci:. oi '.he lungs. those bodies are no lunger capaule of scruicnmg As for as I have been able to discover, it is Mill tiic delicate surfaees of me air spaces. true that only certain forms of free silica anil the Finally it is inns! suggestive that among ilu/ons group of fibrous silicates known as asbestos, are of different silicate minerals only the five known capable of producing fibrosis in a normal hint: as asbestos, winch are unique because they are Many other silicates have been incriminated by fibrous in structure, should be commonly lecng- roentgenologists, but when autopsy specimens nized as pulmonary irritants. The variation ::i have been examined it is discovered that there chemical composition within this group is greater is associated chronic infection or that the inhaled than that between them and many other silicates dust contains significant quantities of free silica. In fact chrysotile asbestos lias the same cheum.il I shall first compare the action of chrysotile as formula as a non-fibrous silicate, serpentine, bestos with that of quartz upon experimental ani which is physiologically inert. Ohvinusiy irrita mals and review rniisiilernhlr evidence bennn;; tion would .eeiii to he a: ..oei.iled with the phi ..1e.1l. on their respective modes of action. A few of rather than the chemical, composition of these these observations now have urnctical significance: minerals. others may prove to be quite unrelated to the One point of practical significance may be indi pneumoconioses found in human beings. cated by these observations, namely, that very finely ground asbestos is not dangerous. This FOR the last year or two we have been coming conclusion has support in clinical observation, lor to the conclusion that inhaled asbestos fibres it has long been known that at the Thelford mills j are irritating not because they are silicates but bethere was no clinical asbestosis even though m j cause they are stiff fibres which mechanically ir former years the atmosphere was very dust;, ant! ritate the lungs. Unlike the free silicas, these the dust was extremely fine. The tact that :ahri- ' minerals will not stimulate fibroblasts in anv part cation of fibres of the same mineral in American of the body; only those in the lungs are affected. plants could produce disease was one of the puz It was inferred that these organs were affected zling features of this disease. But these experi because the movements of respiration arc so much ments offer a plausible explanation. The fine dust more rapid and continuous than those of other in the mills is composed of serpentine and ex viscera. Then it was discovered that if asbestos tremely short chrysotile fibres; that in the spin was ground very finely so that few of the fibres ning and weaving mills contains many more lme. were longer than 2in length the irritating prop fibres. erty of the asbestos was practically destroyed. In I ufr halation experiments with such fine chrysotile N THE case of ;ree silica everything points to asbestos have now been continued for three years. a chemical form of irritation although the solu 'To fibrosis has developed in spile of the fact that bility hypothesis as now conceived is not com an average atmospheric concentration of 125 mil patible with all the observations that have been lion particles per cubic foot of air has been main made. In experimental animals inhaling or in tained. In contrast I would point out that in a jected with excessive quantities of pure quartz previously reported experiment* one third this or flint in exceedingly fine state of subdivision, it concentration of long fibre asbestos dust produced can be observed that tissue reaction takes place well marked fibrosis after about two years. in two stages. First there is an acute inflamma If the effect of asbestos were chemical, one tion resulting in necrosis. Following it there is would expect that a decrease in size would ac healing with fibrosis in the form of a granuloma celerate tissue response. With free silica large whose end product is the silicotic nodule. The particles have little effect, but as their size de collagen laid down by the connective tissue cells creases cellular reaction becomes more vigorous is modified in a peculiar way analagous to tha; in j and even constitution?.! symptoms may ensue.- the tanning of leather, and this is responsible for With fibrous asbestos the reverse is true. the characteristic hyalinization of silicotic fibro The histology of early asbestosis does not -ig- sis. Incidentally, leather has been tanned with gest a chemical injury. Even under the most ex silica and sections of such leather reveal that the treme conditions that can he created by artificial collagen has undergone a similar hyaline trans injection there is no preliminary phase of tissue formation. In human subjects only cases of rapid J necrosis with infiltration of leucocytes as occurs ly developing silicosis show evidence of a t\v 1- with high concentrations r* v*ng fine quartz. The stage reaction. In those with ordinary chronic connective tissue L>ills merely multiply very slow disease, degenerative changes are slight and ow: - 1 ly in ar"* v:.ert.Tru 5 fibres :se. CC-u^Kt -hadowed by the formation of connective tissue j Vol. No. 3 JN1H .STKIA1. mkdicink /'mic ** The solubility hypothesis is based sulci'- upoll tides u! larger size ai d it has not been noserwd indirect evidence. 1: is known that colloid;.: s.hc.i on in ted mg suspensions <>f several oilier nm.Lrais is toxic and that quartz will dissolve to .--me ex gii-uiM lo the same particle size tent in slightly alkaline llouls nl the same | M Sv inplu'ti.. an- imli.ded even before eompielmg those of '.he body. Hut it has never been possi the injection bv the iii.se! of rapid, labored lesiui- ble to prove that silica has dissolved wilhm the .iI uni. Tin - skin ol tin- .ind r\; remitii a becomes body, because the solubl" material is immediately pale. Tin* animal displays uncoordinated mus combined with local tissue elements. It is now cular movenieiHs and spoi.idie convukmn-. i,-i- generally accepted that the .soluble silica ! teele.l mm.ilie:: in iii atb il the tlo-.i- e. sliflieient When in the urine and blond probably comes li"in in smaller Joses are udiomislci ed complete i eeoverv gested food and dm:k rather limn from inbalcd take.- place. dust. Aulopsv nl fatal cases iIisi-Iom-s an mtri.se en gorgement of the spleen, omentum and subnen- WE have made a pond many experiments wlmsc tone.nl tissues which are deep jnirplc-rc-d in color. results are diiTirult to reconcile with the solu Tin- liver, and in fact practically all the remainder bility hypothesis. They do not necessarily invaolfi ilie bmly, is almost bloodless. Counts of tardate it because we iniiv mil have all the facts and vcin blond show only about half the number of do mil know Iiiiw |o inlorpi ol lltoili. For examplo. leuroryn-s present iusl before the injection and wc have found llial collnl.n n."linns 1 n t;111 wilhm i roi i e-.piiinlinr leducli"!- III ii-d blood cells The 13 to 3(1 minutes after injecting line particulate blond ii" longer clots. There is no homnlv-us silica. In the test-tube traces of dissolved silica Animals that .have recovered from one reaction are only discoverable by nr. t-scrrdingly srnsilive seem to acquire a tolerance so that in some in colorimetric rcacliun alter 13 to 34 hours. Possi bly "vital" factors may accelerate the process, hut no means of evaluating them has yet been dis covered. No one has ever produced fibrosis by single or repealed injections ul Use various forms of soluble silica. The effect is apparently not due to the quantity of silica dissolved. for many of i Ininert silicates in vitro are more soluble than quart/ or flint. Evidences of alteration of the surlacc of quartz particles long in contact with living tis sue have thus far escaped detection. In years of experimenting to discover the mechanisms by which lice silica exerts Us pe culiar effects upon living tissues we have re peatedly observed evidences of a specific toxicity. Guinea pigs, injected inlrapenloneally with largedoses of fine quartz particles are often obvmuslv sick for some hours. When Mr. Cummings and Mr-. Rcd!in: were seeking an avenue for the stances at least twice the former dose may be in jected without symptoms. The degree of toler ance. however, varies widely in different indi viduals. Tiiese symptoms are not influenced bv the in jection of adrenalin. They arc not reproduced by transfusing the blood of an animal dyinc m shock .nto another one of the same species. Taw are or.lv exhibited or. injecting .suspension:: of quartz particles less than 3" in diameter. They are not produced by injecting the supernatant salt solution from which the quartz particies have been removed by centrifugation. The seventy of the reaction does not vary with the age of the par ticle suspension, although the amount of soluble silica increases on standing. The toxic effects of quartz can be more or less effectively neutralized by adding small amounts of different substances. Colloidal aluminum hy quantitative inliuduclion of silica they tried in travenous injections into rabbits and discovered the method which we now use as a standard for comparing reactions to different dusts. But in cidentally they found thai Iht-se animals would die very promptly if the unit dose of quartz par ticles were too large. These deaths were not em bolic because they did not occur with large par ticles but only when the quartz grains were 3,. or less in diameter, and they did not develop on in jecting suspensions of other minerals ground to the same size. Mr. Dworski and Mr. Delahant have extended these early observations in a long series of ex periments that have yielded interesting though droxide gives complete protection in a dilution of 0.03',; ; colloidal ferric hydroxide is much less effective. Animal charcoal cannot be injected, be cause it flocculates with the quartz and produces emboli. The finely ground metallic aluminum, used by Denny, Hobson and Irwin4 in the preven tion of silicosis has no influence upon acute in toxication. Further experiments are in progress to verify the conclusion of these authors that aluminum coats the surface of the quartz particles with insoluble material.* Recent observations indicate that all species of animals arc not equally susceptible to intravenous injections of quartz. Dogs, which develop sili cotic fibrnsis very slowly and under conditions puzzling information. They have shown that line silica injected into the left side of a guinea pig's heart acts like a strong poison. not vet defined, tolerate intravenous injections of comparatively large doses of fine quartz without symptoms of ant' kind. Rabbits, guinea pigs and Symptoms of shock followed by death within a few minutes to one hour occur when a 400-gram white rats all die of shock. Soluble colloidal silica m dispersed phase is also guinea pig receives an intracarduic injection of or 4 cc. of a suspension of 1 to 3,< quartz par ticles in physiological salt solution. The reaction * Subsequent experiments have shown tnat stcrihaims mmus nf nicinllic aluminum Iy hrat oestn**** t! *i |K\vi*r nf iHMJiralutn^ ;hr actum if .sihea. Unhcnum su>* is sp-cifttM thai'- iSrtatpnAjuzed by quartz par- IX'nsmn* nf the mrtal an* tost ;* i*fTTUvr ns th<- hv't4.. V l* I c bauc 4$ INDUSTRIAL MEDICINE Fv :r*< toxic, and intravenous iniivlmiii produce thr rc- )"i.ri-ti i>* l> i|Uile unin.lui iu i u e\ iin iccvsieu actions just described with t-xtu-melv small buses. n.aUTial 1m me case of particles o., nr u:uicr me With larger ones death occurs promptly with number inside each phagocyte was countless, and symptoms referable to the respiratory tract. The there was marked evidence of degeneration of the lesions are then confined l<> over-disteniiun of cytoplasm of those cells. In other words, the cf- the limps anil swlipli-ural |<-t<< 11i;i 1 hemorrloipes fecl of surface an a hail to he exerted inside of !he cell and not upon the body fluids as a whole. Ex THE results produced by injecting particulate tra re! lu la r quartz seemed to have little influence, silica into the circulation all suggest a rela and oven mli .icelluiar particles of a l.irgc run tionship to a large amount of mineral surface sudproduced no visible evidence of irritation. denly brought into contact with the blond or tis sues. This is borne out both by the absence ol reaction to large particles in excess of .V in diam eter and possibly by the observations on neutral THIS observation brings us bacr. to the cans'of these progressive changes. Apparcidiv they are initiated with degeneration in the pri ization. Any effect due to preformed soluble mary phagocytes, an efTect which is exui fly paral silica liberated in the suspension before injection leled in the histogenesis of tuberculosis. Some has been eliminated, and no active soluble silica tours ago I published a paper calling attention could be demonstrated in the hi nod of an animal to the similarities between silicosis and tuber dying in shock by transfusion into a second host. culosis.'' In both of these diseases the primary Everything now suggests an effect taking place irritants. (piarU grains or tubercule bacilli, as very rapidly at the interface between the quartz the ease may be. intoxicate the phagocytes. In and some element in the blood or tissues. Whe tuberculosis the cells thus poisoned are commonly ther this is due to the very rapid production of designated as "epithelioid cells." in silicons liu colloidal silica in this location or to unique elec morphological cflcct ;s similar. Visible lut trical properties of quartz is still a fascinating droplets accumulate in the cytoplasm and the subject for speculation. In the same category is elements siainablc by supravital dyes undergo the demonstration of the tolerance conferred by rearrangements in characteristic patterns. Giant previous injections. The manifestation of acute toxic symptoms by those species of animals which develop silicotic fibrosis most readily and their absence in the dog, which appears to be much more resistant, sug gests that these immediate reactions may have some bearing on the etiology of silicosis. Until more is learned about the reactions in the dog no cells of the Langhan's type are produced in each disease by stimulation and repeated multiplication of the nucleus. In each disease many cells die and their degenerated products are liberated in the tissue spaces. Incidentally it is the paoulum of necrotic cells in silicotic lesions on which tu bercle thrive so well, an effect which is responsiole for the high frequency of complicating tuber inference is possible. The influence of particle size is just as signifi cant in the production of advanced silicotic fibro sis as it is in eliciting acute symptoms of intoxica tion. Many injection experiments have convinced us that quartz particles over 3m in diameter arc of little or no physiological significance. The fact that the lungs of persons exposed to most dusts contain few particles larger than 10m in diameter has been responsible for the establishment of tms size as the maximum important in dust counting. As a matter of fact we know that with some dusts there may be many larger ones. While it would be just as well that any large fragments should be excluded from the lungs, it is felt that only ones 3m or less in diameter are responsible for causing silicotic fibrosis. We have long maintained that particles of this size are irritating because they present a suffi cient surface of silica to the fluids. Recently Mr. Dworski decided to test this reasoning further by injecting graded coses of different sized quartz particles which would all present the same total surface area. He found, however, that regardless culous infection in silicotics. In the tubercle it is in the necrotic or caseous tissue that tubercle bacilli are most frequent. Perhaps they not only cause such caseation but they themselves thrive on it. Coincidentally more cells migrate to tinarea and proliferate to form the granulomatous nodule that is characteristic of each disease. Finally the production of necrotic tissue, high in lipoids, by two very dissimilar primary irri tants recalls the experiments of Fallon* and his hypothesis that it is these lipoids which are di rectly responsible for the formation of the granu loma. He showed that the injection of such lipoids, freed at least partially of contaminating silica particles, was capable of producing a granu lomatous nodule. Such mechanisms may be involved in the pro duction of both silicotic nodules and tubercles. It still remains to demonstrate the nature of the primary injury by each of these irritants, and it is this problem that will probably engage our at tention for some time to come. Bibliography: of the total surface, silicotic reaction only dr*, 1. CAiuiNr.it. L. U.. and Cimminck. 15.E.. Studir- mi veloperi when the size of tin- particles was U,, nr F.xm*nim*til:il TVnriimm-nniiiMS1 V! Iiili.il.ilmn nf Axlir-ai*- less. On examining his material it was discov ered that with particles 4 to 5m in diameter or larger there were only two to fqur visible in a thin section of each phagocyte. These cells ap- I5usl. Ilf LilU-ct upon Primary Tubitiuluus lulalmn J lutlust. Hun.. 13.G3-G8 and ST-114, February and Marcn. 1S31. Z G-Viiiixui:. T.. 1'.. and Cummiscn. 15 F..: The Rcarlimi !>' Kmc and Medium-Sized Quartz and Aluminum Oxim Vol. . No. - INDUSTRIAL MEDICINE Poop -iP ftrUClbi. Silicone CurlioM <>: I hi Livrr. A "> J Hath . jg33;9. Supplement l>*ili- nuinucr 54. Til-Tt*3 J. Timothy Liaav perw-nai Communication 4. DtNKY. J. J. Hopson. W P . ami Inwin. 1i A Tii- Prevention of Silicuus by Metallic Aluminum. Canad. iS.A /-37:1-11. 1937 5. Gardner. LrL\. The Siirnhiriiy of the u-sioiu Pro duced by Silica and tin- Tubercle Uacillu*. Am. J 1`ath.. 13:13-22. January. 1S3T. g Pau.on. J. T.: S|-rific Tissue neaetioii to l'liuspholipids: A Suwesied L.\pl;in;itin for the Similarity of the Lesion* of Silicosis and Pulmonary Tubci culosis. Ccnad. M. A. J- 3C.==3-=2. 1MT A Plan for the Control of Tuberculosis in Industry Max R. Burnell. M.D., Medical Director, /.C Spark Piny Division, General Motors Corp., Flint, Mieiityan IT IS a proud day when it can be stated that one of the safest places lo be in this country is at work. Statistics from the National Safety Council seem to bear this out. The reduction the frequency and severity accident rates in uur industrial institutions has been nothing short of remarkable. Prevention has been the watchword. With such improvements, the consideration of the medical departments in industry has more re cently been drawn to the general health of its em ployees. Attention to the control of tuberculosis has been a very major issue. We believe that m no adult group throughout the rountry can so much be accomplished in prevention and early recognition of this disease ns in our industrial in stitutions. Legislation varies in the different States regard ing occupational disease but the ultimate objective of this legislation is clear: The general health of the employee must increasingly become the re sponsibility of the employer. While the status of tuberculosis has been debated by many legisla tive bodies, silico-tuberculosis is definitely com pensable. In the state of Illinois the new occupa tional disease disability compensation law went into effect on October 1, 1936. Dr. C. 0. Sappington states that "during the first year of the ODeration of this law, 10.9'r of disability claims filed were for pulmonary tuberculosis while silicosis claims were 15 9c of the total."1 The corporation that is looking toward the fu ture with the best interests of its employees m mind certainly should be actively engaged in the problem of the control of tuberculosis. Many of our industrial institutions have already shown, by marked reduction of the incidence of pulmonary tuberculosis, just how this can be accomplL.ied. Our own corporation has a very definite program concerning tuberculosis. THE PROGRAM: 1. ' Physical Examwtatic ls givt"' '.her. Pre - Employment -y prospective :ics* :r.a- tior.. This is done with the inu-iit of placing that individual in industry where lie or she is best physically as well as mrntallv luted. Tin* exar.- mation is not done for the purpose of eitner pass ing or rejecting that person ior employment. Tms pre-c:iipld>ment examinati :i gives the examn.ing physician the best possible opportunity to netect nulmonary tuberculosis. Dr. Robinson Boswortli. President of the I:iinuis Tuberculosis Association, state:::- "C5'i of adult pulmonary tuberculosis has its beginning in the ai'.e group 11) lo 'Jll. In ihc vast majority ol case:! there arc no symptoms and no physical i.irivs " it is exactly this age group that concerns us most in our pre-employment physical examina tion. for it is during this age period that mo*: em ployees first enter industry. We therefore lee! that such an examination is not complete w::hnui an x-ray of the chest. We believe, with Dr. Andrew R. Riddell, of the Industrial Hygiene Department. Ontario Dip.iriinenl of lie.illli, that Die wholesale lubcieulm testing in industry ha:; many disadvantages. He states that3 "the individuals must present them selves at least three times--there is considerable disruption of work--even after most careful ex inplanation as to the meaning of the test, the em ployees wiio react positively are greatly dis turbed." Applicants in whom active pulmonary tuber culosis is discovered are sent to their family r. ys.cian. Our roentgenogram is at his disposal, but must be returned to our files so that we can later compare the progress of the disease and determine at what future time those persons may be pro nounced employable. Applicants with arrested or quiescent tubercu losis arc placed at work after being informed of their condition and instructed to return for pe riodic examinations. These examinations for new employees, in this classification, are conducted every three months. It has been increasingly evident that our re sponsibility does not end there. We explain to the employee that while he now has an arrested tuberculosis, it was once active. We encourage him to have the members of his family examined by the family physician. We feel that not until then has industry wholly discharged its duty to the community. 2. Periosic Examinations for Old Employees. These examinations are made at different times and for varied reasons: (a) Upon returning to work after vacations. (b) After absence caused by an illness. (c) Re-employment following seasonal lay-off. (d) Transfer from one type of work to another. (e) Medical department requesting the exam ination for some definite reason. (f) Volunteer requests by the employee for such an examination. Little comment is necessary concerning these examinations except to stale that every employee comes into our medical department for a general physical check up at least once each year. Two types of periodic examinations deserve