Document 1yY2BKNo8R91oXDOmXQVRBm5E

MECHANICAL ENGINEERING Published by The American Society of Mechanical Engineers VOLUMB 57 Number i Contents for February, 1935 LABOR-MANAGEMENT COOPERATION IN METHODS DEVELOPMENT . ......................................................................................... R. C. Nyman THE AUTOMOBILE OF 1935 .................................................................................................... 73 78 APPLICATIONS OF SCIENCE TO THE MAKING AND FINISHING OF STBBL . ..........................................................................................John Johnston 79 engineers' business contacts...................................................A. G. Christie 87 OCCUPATIONAL DISEASES-----PROBLEMS OF PREVENTION . . F. R. JonCS 90 administration of occupational DisBASB control . . A. S. Gray 92 toxic dusts--origin and sources in industry . . R. C. Stratton 95 progress in power............................................................................. C. F. Hirshfeld 99 THE APPLICATION OF CENTRAL-STATION PRACTICE TO DOMESTIC HBATING ......................................................................................... M. K. Drewry 103 EDITORIAL............................................................69 ENGINEERING PROGRESS .... 110 LETTERS AND COMMENT . ... 122 A.S.M.E. BOILER CODE..................................125 BOOKS RECEIVED IN LIBRARY . . . 128 what's going on ..................................129 DISPLAY ADVERTISEMENTS .... WHAT'S NEW...................................................14 1 PROFESSIONAL SERVICE...................................29 CLASSIFIED ADVERTISEMENTS ... 30 INDEX TO ADVERTISERS .... 32 OFF1CBRS OF THE SOCIETY: RiOH E. Flanders, Prttidtnt Eric Oerro, Trtaiurtr C. E. Davim, Stmtary PUBLICATION STAFF: Georob A. Stetson, Editor Frsdbrice Last, Adrtrtiimg Mfr. COMMITTEE ON PUBLICATIONS: S. W. Dudley, Chairman S. F. Voorrsbs W. F. Rtan G. F. Bateman M. H. Robert* ADVISORY MEMBERS OF THE COMMITTEE ON PUBLICATIONS: E. L. Ohlr, St. Louii, Mo. E. B. Norrii, Blaceseuro, Va. Junior Member, O. B. Schiee, 2d A. J. Diceie, San Francisco, Cal. Published moorbly by The American Society ot Mechanical Engineers. Publication ofice at 20tb and Northampton Streets. Easton, Pa. Editorial and Advertising departmeOta at tilt headquarters ot the Society, 19 Weat Thirty-Ninth Street, New York, N. Y. Cable address, "Dynamic," New York. Price 60 cents a copy, $3.00 a year; to members and a&liaccs, 30 cents a copy, $4.00 a year. Postage to Canada, 73 cents additional, to foreign countries, $1.30 additional. Changes ot address muse be received at Society headquarters two sreeka before they are to be effectiee on the mailing list. Please scod old as well as ocw address. . . . By-Law: The Society shall not be responsible for statements or opinions advanced in papers oc . .. printed In Its publications (Bl, Par. 3). . . Entered as second-class matter at the Post Office at Eartoo, Pa., under the Act of March 3,1179. .. . Acceptance for mailing at special rate ot postaitr provided for In acctioo 1103, Act ot October J, 1917, authorised on January 17, 1911.. . . Copyrighted. 1933, by The American Society ot Mechanical Engineers. OCCUPATIONAL DISEASES1 The Problems of Their Practicable Prevention in Industry By F. ROBERTSON JONES association of casjaltt and sum Etaamvas, nhv itaz, n. r. NDUSTRY has so many ind such a wide vancry of major chargeable to health-hazards which industry itself creates. I problems these days that to many the problems presented by occupational diseases among workers may seem com Even that is too broad a subject for me to deal with in a brief introduction. Therefore I will restrict my remarks generally paratively insignificant. This is, however, far from being theto prevention of occupational dust diseases of the lungs, with case. Hither from the standpoint of cost or of social better particular reference to silicosis--since those diseases, of which ment the situation confronting many employers as a result of silicosis ranks first, have now given rise to s problem of such their growing liability to provide compensation for or pay magnitude and pressing importance to industry as, temporarily damages to the victims of occupational diseases is equally as at least, to relegate other occupational diseases to s position of serious as the ever-increasing tax rates and the prospect of relative immateriality. soon being compelled to contribute to unemployment insurance From what I can learn the disease now known ss silicosis is funds. Speaking as a representative of the largest stock as old ss history. But whether because of s recent increase casualty insurance companies of the country, I can assure you through the use of modern machinery, or because of s growing that these companies are well aware of the almost overwhelm public recognition of its seriousness, or because of these two ing burden of cost which seems about to be heaped upon factors in conjunction, and possibly others also, silicosis has industry by the general extension of the compensation system now become a mortal menace to induatry. Whether under a to cover occupational diseases of all kinds. Our companies, system of employers' liability for damages or under a system of course, have only what might be called an indirect interest of compensation--"regardless of fault"--for occupational dis in the problems you are discussing, but they will be adversely eases, rile cost of silicosis is becoming to heavy ss to entail affected if necessary insurance costs grow so great that they the rapid or gradual ruin of many indnstries, unless die inci will be "more rhan the traffic will bear." They are naturally dence of the disease can be radically reduced. The cure of tremendously interested in these problems and anxious to silicosis, once it has progressed beyond a very early stage, is, cooperate in their solution. It is my opinion, which I believe according to the preponderance of medical opinion, practically firmly to be well founded, that the primary essential in meeting out of question. Consequently, for silicosis, fmtmfum is most the problems of occupational diseases is prevention. If these emphatically the primary and principal problem. diseases, through engineering and the medical sciences, can That problem has engineering, medical, economic, legal, be reduced to the level of exceptional misfortunes, the remain educational, and political aspects all of which need to be ing economic and legal problems can be readily solved. It realized by all concerned in the cask of prevention. therefore seems to me that most intensive consideration should In its engineering aspects, the principal problem in inven be given to this phase of the situation immediately by the tion of silicosis is the removal or prevention of inhalation outstanding experts of the country, so that suffering by work of dust. As a layman I cannot imagine how, practically, all men from preventable maladies may be reduced to a minimum dust can be removed or kept from inhalation. Therefore, and so chat industry may not avoidably be drained of its primarily at least, efforts should probably be directed princi resources. The character of this meeting and the program pally to the elimination of harmful dusts. Here you sie con to be presented indicates clearly that The American Society of fronted with several difficulties. The preponderance of medi Mechanical Engineers is alive to the situation and has the cal opinion is that, of the inorganic dusts constantly gencratsA cooperation of the medical fraternity in its most laudable in industry, only dust of free silica (silicon dioxide;), and objective of prevention. perhaps asbestos dost--and these dusts only when in minute The specific subject for discussion at this meeting is the particles--are harmful, that is, harmful in the setae sod to "Engineering Aspects of the Prevention of Occoptdonal the extent of cau*m&_ipedfic disabling,diseases of the-lungs. Disease." It is not my purpose to much to enter into this But that is merely a majority opinion, from which there are subject as rather to lead up to it by calling to your attention dissents; and it is open to doubt. Only a Jew months ago a some aspects of the psoblem not special to engineering but high authority1 on this subject in Gnat Britain declared: which industrial engineers should study and bear in mind. "We need a scientific `recessional' in which to reexamine From the start, it needs to be borne in mind that all forms with an open mind many of the generalizations now accepted of ill health--"occupational" or of ordinary life--to which as current coin in relation to tllicorie and `miners' phthhus.' " industry in any wise contributes, as, for examples, through Moreover, silicosis is, in colloquial language, "all mixed up defective lighting or ventilation, or excessive exertions, or with" tuberculosis. Apparently, tuberculosis induces silicosis, exposures to the inclemencies of the weather, are marten for sod silicosis lessens resistance to tuberculosis, or something prevention. That, however, is a cyclopedic subject. You like that. But tuberculosis may be caused by organic dost or, have advisedly restricted your discussion at this trssioo to the for`all that I can leans to the contrary, may be indirectly topic of tctsfstimsl diseases--which I construe to mean--in activated by other dnsta. Consequently, how hr all dusta, popular phraseology--those diseases, not of ordinary life, or, if not all, then what data imperatively need to be elimi Contributed by the Safety Conuaictes and mans* at the Aaaaal Maatiafe Saw Turk. S. T., Doccnbm 5 id 7.1954, of Tms Asoucam c----------- M--| -- |, Ewnar--s nated is, aa yet, a problem to be determined largely by etpexi- Prof. S. L. Adviser to the British Tsbtrcatoris leearth Committee, quoted in ImJmjtritl Madfcfer, April, 19)4. 90 Fbbxvajlt, 1935 91 mentation, not based i priori oo praeat medial opinion, bat ou the faults of experience on the results in the way of reducing morbidity from the use of specific mesas for preven tion, engineering means among others. A problem of vital importance in the study of engineering mrn of prevention is the determination of what is practi cable--economically and humanly. Economically, the bat means for prevention may often be impracticable. Industry cannot afford to be continually replacing its machinery to experiment with the latat gadgets. It would be a jump out of the frying pan into the fire to load an industry to death to prevent exposure to an occupational disease; and some means of prevention may be such that the workmen simply cannot be induced to use them properly and consistently. This prob lem will be particularly acute in the smaller undertakings. What is practicable in large and well-organized establishments is often impracticable in minor operations. Thus in the prevention of lead poisoning, the well-established paint fac tories have been almost completely successful, whereas among the job painters the incidence of that disease has been very lictle reduced. Results will probably be similar as to silicosis. In South Africa, where silicosis seems to be concentrated principally in mines, generally large establishments, measures of prevention are succeeding in reducing the incidence of the disease, encouragingly; but in Cumberland County, New South Wales, where a scheme of compensation for silicosis applicable to such small-job trades as quarrying, rock drilling, sewer excavation, etc., is in force, it seems that little progress in prevention is being made, though strenuous medical means are resorted to. It may turn oat to be a job for engineers to discover means for prevention of silicosis practicable for the "little fellow." At least that point will require study. This question of what is practicable, as distinguished from the ideal, leads up to another aspect of the matter. In my opinion, besides studying the bat practicable ways and means for prevention, engineers should alio give consideration to the formulation of mrnimm standards, and to ways and means for procuring their observance. Authoritative formulation of such standards is needed for many purposes--to impress backward industrialists, to guide and support insurers in granting or refusing coverage, and to furnish a scientific basis for regulations to be enforced by public authoritia. A code of such standards needs to be elaborate, so as to fit different conditions, and to be open to continual revision, to keep abreast with the developments of research and experience. A present obstacle to prevention, not often realized but of no mean importance, is that many states have laws which imptw upon employers itUt/inin obligations for the protection of the health of employea, such as to provide "adequate" venti lation, and to do this where "practicable" and to do tha t where "reasonable," subject to liability for damages for non-com pliance, leaving it to juries in litigated casa to determine what is "adequate," "practicable," or "reasonable" under the circumstanca. How can any of you expect an employer to go to much expense to follow your advice when an ignorant and misled jury may mulct him in damaga for not doing differently? In my opinion, it is practically essential to pre vention by engineering means to procure the replacement of such laws as these by public regulations prescribing dtjmttt standards, for the development of which your cooperation is requisite, and to get rid of the disturbing influences of jtiria in determining engineering quacions by means of the adoption of "compensation" as the exclusive remedy for occupational diseases, for which your assistance would be of great weight. All this chat I hare had to ssy has been discursive as a whole and speculative in parts. I hope, however, that it will be of some use to indirate to you the ramifications of your subject and how the particular topia to be discussed today fit into the broad problem of prevention, in the solution of which technicians in many lino most all cooperate. a aaTnax o> uacxixts that cohvuet solotions o* csutaca nttxats ox cmxtmaa acaxaxa nrro raxNtsAUMT, fLExntM nut aasx. raoase mxk, moaEsrm, sr. r. NDUSTRY, in order to stay in business and I Tpairmin its position in the economic world of today, most avail itself of all the materials sad processes which have been shown to increase The Administration the efficiency and speed the output of its produc tion. New substances and processes and new uses for of OCCUPATIONAL older ones are constantly being utilized by in dustry. New chemicals, plating solutions, dopes, solvents, degreasers, condensation products, varn ishes, paints, lacquers, dyes, abrasives, and DISEASE CONTROL fabrics--substances used to increase and broaden production--are often employed without a knowledge of their possible effects upon health. A fixe hazard is eliminated by replacing an in By ALBERT S. GRAY flammable solvent with one that is not inflam mable, without the realization that there has CONNECTICUT STATE DEEASTMBNT OP HEALTH been substituted for the fire hazard a hazard to health in the new solvent. And it is in the use of these new substances and processes (and some of rhe old) cutely, the conditions predisposing to occupational disease are char the health of the workers is affected and occupational mote subtle. They are not so attention-compelling as an disease results. accident; they may appear only as increased labor turnover or This has been recognized by a number of states, and though decreased production. The effect upon the individual is uot compensation for occupational disease was originally limited so self-evident, and to the canse of the condition is not so to a few specific occupational diseases, schedules have been readily recognized. gradually enlarged with a tendency, perhaps, toward the There is nothing particularly arresting in the gradual loss of blanket coverage which has already been adopted in a number power in the hands of those absorbing lead; nothing to stimu of states. I am not, however, confining my discussion of late the interest, no startling appeal in the slowed gait and occupational diseases to the limited compensation interpreta mental peculiarities of those exposed to certain solvents; the tion of them, but shall consider them in the broader aspect of development of anemia and tiny hemorrhages in those exposed the effect of industrial environment on health. Hayhurtt to other poisonous materials; or the gradual development of defines occupational disease as "Injuries and disturbances of fibrosis of the lungs horn exposure to certain dusts. The onset health contracted in industrial pursuits or other vocations in is gradual, the change imperceptible from day to day, until lives as a result of exposure to toxic agencies, infectious or the individual either leaves to be replaced by another worker ganisms, or other conditions inimical to health." who passes through the same cycle, or remains at work under Unhealthfol industrial environment not only causes specific progressively lessened efficiency until he can no longer work or occupational diseases but increases the incidence of disease becomes s compensable case. If he leaves for employment among the genera] population. elsewhere,1 he continues at work at lowered -efficiency for a The life expectancy of the industrial worker is several years greater or leas time, dependent upon how much of the material less than that of those otherwise employed. Tuberculosis he has absorbed. The body is capable of wide adjustment to rates are much higher and pneumonia rates twice as high in the environment and much harm may be done before evidence of industrial group. Mortality rates for degenerative diseases the condition is noted. are two to three times as high in the industrial group. Occupational disease is not a new problem but it is only According to the 1930 Census there were more than 13,000,000 within comparatively recent times that we have attempted persons gainfully employed in manufacturing and nwhanical to measure, definitely and accurately, its relationship to indus industries and the extraction of minerals in the United States. trial environment. We now know that there is; a very definite And in these industries there are more than 900 occupations relationship between the health of the individual and the potentially hazardous to health. environment in which he works. We have been able to estab The control of occupational diseases, therefore, may be teen lish the smallest amount of many of the materials used in to present a public-health problem of the first magnitude. industry that will affect health (which we have called the Mechanical engineers have a tremendous responsibility in "threshold dose"), and when this information is not available, the control of these diseases, for in the majority of instances the amount which good industrial practice dictates; sod we this control is bat the application of mechanical principles, can now measure the exposure of the individuals to these whether it be enclosure, ventilation, or both. materials to determine whether this amount is exceeded. We The progress of accident prevention during the past ten or know the amounts of toxic materials and the processes that fifteen years has resulted in the saving of thousands of lives will affect K**1**1 We-know that if these various materials and millions of dollars. A much grester saving may be and processes are not controlled they will seriously affect the accomplished by properly administered occupational-disease health of the individuals exposed to them, and may even control. There has not been the incentive to prevent the affect the health of the people in the community. occurrence of occupational dtsetse that has been accorded accident prevention, for an accident is self-evident; a man txs coanmcnanr auaxao as occusanowix owutm slips on.the floor, falls, or is burned or caught in a press Connecticut, in 192S, recognising the tremendous importance there it no question that he is injured and how. Unforru- of the effects of industrial environment on die health of the Cootribated by the Safety Committee and presented u the Annual Meeting, New York, N. Y., December 3 to 7,1934, of Tua Asmstent Socatrr ot Maratman. Enonwas. workers in the state, set up as part of the Sate Department of Health, a Bureau of Occupational Diseases under statute which provides that all cases of occupational disease be re- 92 Fbbuuaiy, 1935 93 potted to the State Department of Health and which authorizes investigation of conditions causing or suspected of causing ogcopstiooal disease, and which further provides that reports of occupational disease or the results of investigations cannot be used as evidence in compensation claims. This bureau receives and investigates reports of occupational Mi-r*** made to it in accordance with the statute; makes inrveys and field studies of workroom environment, including tpecial determinations of dusts, fumes, gases, or ocher toxic materials, measurements of ventilation, illumination, etc., or tay condition or process thought to be affecting the health of industrial employees, to determine whether the environment is safe or where and to what extent a health hazard may be present. It provides a central source of information for physicians, industry, or any agency interested in the cause, treatment, or prevention of occupational diseases. It maintains in this connection a reference library containing the most recent information relative to the effects of various industrial mate rials and processes upon health, and in addition, as part of the set-up, a well-equipped laboratory. The personnel of this bureau comprises technically trained men, who in the aggregate possess a broad knowledge of industrial hygiene, of industrial materials and processes and their effects on health, and the capadty to interpret the result of a survey or study as a basis for recommendations for control. JUliAC's FINDINGS RBPOtTXD TO INDUITXT FarVi industry in which a study or survey is made receives a complete report of the bureau's findings, presenting the results of actual physical and chemical determinations of the working environment and the exposures of the individuals engaged in it, with recommendations for the elimination or control of any hazard that may be shown to exist. Acmal determinations are made of the number of dust particles per cubic foot of air and of the concentrations of toxic materials present in the air to which the individual is exposed. These procedures necessi tate the application by specially trained technical personnel of precise physical and chemical determinations. But it is in the proper interpretation of these results that the existence or aoa-exutenet of a hazard is established. It is impossible for a lay inspector to tell by mere inspection whether the dnst or other toxic material in the air of a work room is present in sufficient quantities and is of such a nature ua to constitute a hazard, whether the protection afforded is adequate, or the ventilation sufficient. It is only by measuring she exposure to these materials and processes that we can jcsow that the individuals exposed to them are subject to znjury from them. The repurcs of these investigationi are nor just mailed to the sndustry but are presented by a technically trained nun and discussed with the officials and engineers of the organization, ^his information not only establishes the nature and extent of an existing hazard but provides constructive data which fcngineen can utilize for the control of the hazard. Already the work of the bureau, with the assistsncc of the engineering profession, has resulted in definite improvement " working conditions, changes in processes, substitution of B^ttrials, and, in a number of instances, in the purchase of *tirely new equipment, not as the result of any mandatory axdets, but due entirely to the fact that these industries were given definite concrete information on the effects of the environ<Kon health. The actual requests for this service from ^"Mur have been so numerous it has been necessary to schedule l*tk months in advance. I say "with the aid of the engineering profession" advisedly, for the work of the bureau in the control of occupational '<-* is to render the laboratory and field service necessary to make the determinations of workroom environment, whether they be dusts, fumes, gases, illumination, ventilation, or any mate rial or process chat may affect health--chat is, to measure the exposure and determine whether the environment is safe and if a hazard exists, where and to what extent, and due to what causa, and to present recommendations for its control. If the control involves specific engineering problems, as it fre quently does, that is the job of the engineer; the bureau makes no attempt to provide this type of service, so that in the final analysis engineers have a definite responsibility in the control of occupational disease. thx a6lb or inddstbt in tbs control or occupational disxaxx In any program for the control of occupational disease the cooperation of industry is essential. Possibly one of the principal reasons why industry has been less willing in the past to correct an environment hazardous to health is that little attempt has been nude to provide it with definite data. Such changes as have been effected were largely accomplished as the result of arbitrary orders from a law-enforcing agency and no serious attempt had been made to establish the exact nature and extent of the condition. Industry is penalized through compensation payments if in environment causa occupational diseases, and, if it can be definitely shown that a health hazard exists, realizes that it is a matter of good business to control the condition causing it. But no industry will cooperate to the extent of changing its processes, installing new equipment, substituting new mate rials, etc., on the mere opinion of a lay inspector that a hazard exists. Under such circumstanca it will do only what it is compelled to do, particularly when information secured as the resale of such inspection can be used against it either in the form of mandatory orders, claims for compensation or both. With a set-up such as exists in Connecticut, where the law provida that the results of invatigations cannot be used in compensation claims, with a specially trained technical per sonnel to make determinations and interpret the conditions found in industrial environment, industry is provided with just the information h has s right to demand before it is re quired to change in processes, substitute materials, or take other necessary control measures. Actual determinations of exposures are made in the working environment, and industry is presented with definite concrete facts that not only establish a hazard where it exists but pro vide constructive data for eliminating it. It is our experience that when industry is approached by a health agency in behalf of a health program and is presented with definite data regarding its working environment, in a spirit of service rather than law enforcement, with the assur ance that the results of the investigations will not be used in furtherance of claims against it, it not only accept* the service as a matter of good business but actually requests the assistance of such an organization in the improvement of its general working conditions. TUB XNOINXZa's VAST The engineer's pan in a properly administered program is of vital importance to successful control of occupational disease conditions. As an integral part of the personnel of the Bureau of Occupational Diseases, the engineer can offer an important contribution in interpretation of some phasa of data obtained 94 Mechanical EiroisnKBftXNo iyl in the development of recommendations for control of occupational disessc hazards. The fiId of occupational disease control is by no means confined, however, to that group which may give full time to this problem. With the awakening of industry to the necessity of providing healthful environment, the entire engi neering profession has a large opportunity for constructive work. With the daca at your disposal developed by the type of plant investigation I have outlined, you have new tools and more precise yardsticks. In order to perform your part in the control of occupational disease you must be prepared to predicate your work not on the amount of air or material you remove but on the amount that is left behind and be prepared to meet a standard that will keep the working environment safe. To you we must look for the practical application of our findings and recom mendations. It is you who design the machines and equip ment for the use of these materials in industry. There is, of course, a great deal of equipment used by industry that can be safeguarded in so far as the creation of occupational disease is concerned by additional protective equipment, but it seems to me that you should keep is mind as a future develop ment the importance of taking care of the prohka in the original design to chat hazardous conditions may not develop. Why design s rock-crushing TMrhme without proper collecting devices, s degreasing machine which permits mry quantities of vapors to escape, or an asbestos carding chat subjects operators to 35 millioa particles of dust per cubic foot of sir, when, after installation, these equipments will require additional devices to protect the worker, more expensive and less satisfactory than if the equipment had been originally designed properly to protect the operator? Industry is very much alive to the necessity of providing safe working environment for its employee* and you have a splendid opportunity through the exercise of your profession to profit and do your part in the prevention of occupational disease. An appreciation of the effects of these materials and the importance of such data as I have outlined is not only essential to the proper performance of your task, but will go far in convincing industry that the design and installation of protective devices ia not a tinsmith's job but one for s com petent engineer. wsum A rwasxr mo. 3 tnnvnsax. Tuavr taro ax wcuc xk tmm mcm rimstwo am a KZOBOI ro sisot cm waaxaa A swanr Tuaaax xaxna m `fc-i i TOXIC DUSTS Their Origin and Sources in Various Industries By REUEL C. STRATTON THE T1UVEUU QOO&ANCZ COMEANT HE SUBJECT assigned to me presupposes that many in Air-flushed drills distribute these parades over a wider area Tdustrial diseases are produced through contact with or in chan do water-flushed drills, but the offal from water-flushed halation of industrial dusts of a toxic nature. Personally, drills dries and then becomes distributed in the air.. When I do not believe that the consideration of occupational diseacsreushers are operated, either gyratory or jaw, dust is produced prevention should coniine itself to dusts alone; it should in in an amount depending mainly upon the size of the unit clude all materials produced in such manner chat they may be involved and upon the fineness of the material which is being inhaled by a worker. The question of whether a material processed. exists as a gas, a vapor, or a dust is but one of particle sue and Sizing and screening operations also distribute dust, although chemical make-up; but with materials whose source is in in they may not in themselves be producers. dustry, it does noc seem Bering to stop with substances com monly known as dusts and thus fail to consider those which S&4JT sihxxnq, tunnbuno, excavation, and demolition usually exist as vapors. Drilling operations in all such activities afford opportunity It is a common fault to focus attention upon one object to for dost generation. Again, the exposure depends upon the such an extent chat others of equal importance are thereby rele type of rock encountered. Transportation of materials to and gated to obscurity. For the present, pneumonoconiosis, or from the face or working area also allows dust to be distributed. more particularly silicosis, occupies the center of the stage and Steam-shovel work in excavations exposes workers to dust possibly for the purpose of this meeting such importance is clouds. In demolition work, the pulling of walls, the dropping justified. However, the engineer interested in the control of of floors, the loading and unloading of debris causes the genera occupational disease by plant equipment and operation must not tion of much dust. Blasting operations when required not forget that there are many occupational diseases produced only generate dust through the action of the explosive itself, through exposure to industrial dusts other than silica-bearing but may precipitate other settled dusts by the shock transmitted ones and to vapors, and that the control of these industrial to the surrounding structures or areas. diseases may be brought about through the application of the fundamental principles which will be propounded by other STONE DXBWNO AND FINIffiNO speakers today. At present and until new avenues of control When this activity is in conjunction with quarry operations, are discovered, explored, proved, and utilized, the problem in the same quarry items previously listed pertain. Stone dress many instances almostl acking a complete solution, but it ing and finishing is probably one of the most prolific sources of is unquestionably true that certain occupational or industrial dust known. At least the exposure is one of the most serious diseases need not occur. The engineering aspects of their con due to the intimate personal contact of employees to the area trol arc so well known that in the hands of capable plant of in which the dust is generated. Stone dressing promotes much ficials there can be little excuse for their occurrence. In the hand-tool labor. control of such diseases, industry today faces a problem, the Surfacing work, both hand and machine, produces quantities solution of which rests in the hands of the scientist, the physi of fine dust. Sawing, cutting, and channeling, as well as drill cian, and the engineer. ing, are also prolific sources of contamination. Hand chisel While the generation of dust in various types of industries ing produces a certain amount of fine dust but in- this work the has a more or less common mode of origin, namely, the produc larger particle sizes usually predominate. Hand polishing pro tion of finely divided material, yet it does not teem fitting to duces some dust but only a very small quantity as compared to group industries together even though the operations producing a mechanical polishing mill or jack. Even when 'vet polishing dust are somewhat similar. Therefore, in this paper, opera is done, the quantity of dust is only slightly reelneed. Sand tions will be ditemed as individual'to a general industry blasting operations, if not isolated, are dust producers. Such rather than as individual unto themselves and assigned to many dust generation is cumulative, as the abrasive material is broken industries. While this may produce some repetition of ma and forma a dust in conjunction with the material which is be terial, yet for the sake of those engineers who are especially ing blasted and eroded. interested in an individual industry, I feel the paper will have In addition to the operacions indicated, workers themselves added value. create a dust hazard by the blowing, by means of a compressed- qoaaxT oisunoM air nozzle, of dust which has accumulated around the tools or operations. Although the exposure in a quarry due to dust varies in aeverity based upon the chemical composition of the material BDODOrO CLSANZMO being quarried, most operations are similar. Drilling opera- The cleaning of buildings by hand or machine may be con tens, both well and small-bore, produce voluminous quantities sidered a dusty opendoo. This is particularly true when sand ofsmall particles of the material in which the operations occur. blasting either by air or steam is employed. The seriousness of Contributed by the Safety Committee and presented at the Annual **ronS, December 3 to 7, 1934, of Taa Asraascast Secure or Ma*atocsi. Ettoomaa. the hazard somewhat depends upon the type of material being cleaned. Naturally, this is additive with the dun from the sand used for biasring purposes. 96 Mbchanicai, Enginebjunq vidual items or as balk may produce dust. Spoil heaps unless salted down may generate dust when the ordinary land breezes blow over them. CONOLST* nonocn AMD AiTXJICIAL-rrOMS MAMUVACTtnUMO Mixing operations are dust producers in this q>pe of in dustrial activity. Finishing operations if by landblast or hand tools also produce dust. BUCK MAMUJACTUMKO In the manufacture of brick as well as tile and terra cotta articles there ate several sources of dust generation. The clay-drying department, whether natural material is used or a mixed slip is used, produces dust when the dried materials are thrown into the air through liandling. The dropping on the floors of small quantities of material allows it to become dry and then be dispersed in the sir by workers walking or by transportation. Mixing opera tions give off dust. The operation of pug mills and brick moldert may generate dust through the drying of the waste material. Storage departments may be a source of dust oc casioned through the handling of material. MINTNO The more common form* of mining ue coal, feldspar, glass, sand, metals, mica, refractory materials, and rale, In any form of mining, dust is produced in the use of drills and exca vation machinery. This is true even in open-pit work. The exposure varies according to the rock encountered- As in other cases, the use of wet tools does not entirely eliminate the generation of dost. SAND AMD QlAVeX, DIOOIMO----JTXKT AMD MAX Mrr rnm These two operations are oftentimes associated. Underwater sand and gravel production is relatively noo-hsatrdous but the sizing and screening operation, even though upon moist ma terial, may be a source of dost generation as the fine prtirW will collect on machines, ledges, and para of the buildings and later be swept into the air. When dint and spar milling is carried on either in conjunction with sand and gravel digging or with any other source of taw stock, the hazard varies, as has been previously stated, accord ing to the composition of the material being handled. Practi cally all operations are sources ofdust contamination. Primary crushers, either gyratory or jaw, produce dust; secondary crashers, screens, jigs, air separators, conveyers, and ocher types of machinery generally produce dust in air co a greater or less extent. Bagging, packaging, and shipping either u indi CSSONT AMD tOQ KAMU7ACTUXIMO When operating in conjunction with a quarry or mine, previous sources of dust listed under such headings apply. In addition, all crushing operations produce dost. The charging operations to burners either hand or mechani cally done will create dust. The operations of die finish ing and packing department where bags and barrels are packed, dosed, crated, and shipped are a source of dust generation. lOONDSOi The exposure to dust in foundry operarioes varies only slightly according to the type of foundry. A non-ferrous foundry may be little if any different on an overall exposure from a ferrous foundry. Sand-condition ing operations produce dust. The use of sand cutters or blesdra, screens, riddles, slingers, grab buckets, and other conditioning machinery or operations may create dust. In molding processes the general work on the molding floor or the use of sand throwing aad blowing machines may produce a hazard. The application of parring^compounds to the mold may create a dust. This situation is naturally more serious when the parting material used is of high iree-silica COQtCSt* Shake-out procedure, rattling and tumbling with or without air, sand-blasting, grinding, sad toagging are dust-producing operations. Scratch-brushing work may generate dust. As previously mentioned. Mad-blasting generates dust under any circumstances. Charging operations in loading a cupola or any other type of furnace may generate dust itrthe immediate vicinity and later contaminate the remainder of the premises. The storage of raw stock, sack as limestooe, coal, sand, and pig stock, may through h*Utg generate additional dmic. In addition to the exposures enumerated under mining aad ore production, these exist in the refining operation dusty ex posures. Furnace operations, such as charging aad iIsawing, generate dose. This is particularly true when all or porticos of the charging consist of scrap, such as stonge-ba*- toy plates. Trucking of such may strew the fine material on the ground or floors where it May be picked up aad thrown into the air by walking or by the wind. Skimming, rehealing, and Fbbjlca*t, 1935 Munpling operation* produce dun. The handling of the material in bag houaea, due*, or Cottrell pre- dpitaton may crate a dusty exposure which it particu larly actions during the cleaning operations necessary to keep Cottrell precipitators or bag houses operating at proper efficiency. The transportation of materials in leaky containers, non-endosed mechanical conveyers, or un covered cars crates a hazard. Hand shoveling may pro duce dust in serious quantities. mescuet, zinc, and copras UTINtNO The items enumerated under lead refining apply here also. In the production of zinc, one added exposure ap pears which is the dust produced in the blowing out of re tort condensers, either by barring down or by "shooting" the condenser with a slug of water. BATTSar MANOTACTUXINO--STOXAOB AND IUUUT In the manufacture of storage batteries an exposure to dust crises in the preparation department. The handling, weighing, and mixing of the lead oxides either by hand or machine generates dusc. In the pasting operations, either hand or machine, the material may be spilled upon the machine or the floor, become dried, and later be thrown into the air in the form of dust. The brushing of pasted grids will generate dust in a like manner. On the assem bly line even when only hand operations are in progress, dust may be generated. In the manufacture of primary batteries not only may dust be generated by metal-casting operations, but also in mixing, filling, and scaling. CTEMICAL MANOTACTUBIWO It would be impractical to attempt to list all the opera tions in chemical manufacturing which may be dust pro ducers. Here again the seriousness of the exposure de pends upon the material handled and the amount of material that is thrown into the sir. Chemical dusts, particularly tome dye and dye intermediates, are posi tive sources of dermatitis where the dust generated lodges upon the skin of employees. It is sufficient to say that dusts are generated in the chemical industry sod each in MmmllK IT. T. Boat Dinx MOUNTED ON TB1MO AND EQUIWEP WITH DEVICE KM. TXB ELIMINATION OS SILICA DOST (The. bottles shown on the tripod measure the amount of silica which would be inhslrd by the drill operator.) dividual operation requires study by itself. In chromic-acid manufacturing the sintering of ore is s dust- producing job. The handling and transportation of the ore poor to the sintering either in furnace or kiln produces dust. Oie quenching of the sintered material may generate dust as Uso the crushing of the sintered stock. or machine, the packaging of the insecticides into bags, cartons, barrels, either by hand or mechanically, and the transportation of materials from point to point in the plant generate dust in varying degree. SAINT ANm count MASCOTACTUBSNO ASBESTOS AND ASUROS-OOODS MANOTACTUBXNO Any mining operations and quarry operations are exposures, Previously discussed. In die mannfarrure of asbestos goods, tdculariy dusty atmospheres axe created in the break-out, Ker, sad picking operarioos. The crushing and grinding die fiber, as well as all spinning and weaving operations, ***- tendency to throw asbestos fiber into the air and crate *ne of dust contamination. Crushing and grinding asbesproduaa generates dust. mskxiczds manotactueino Ok toxicity of any dust generated in inwrrv-ide manufactur**des according to the material being processed. There is "Nilirity of operations in most insecticide manufacturing, f^rosxstion department, where the raw materials are manninvolves dusty processes. The grinding of cakes from ^presses, the mixing of different ingredients, either by hand The handling of balk raw materials, as well as the grinding of filter-press cakes, will generate dust. Mixing and. blending operations either wet or dry produce dust. This exposure it inherent in the handling of dry materials, bar the spillage of water-wet materials may dry oat sad later be thrown into the air. Batch weighing when the handling is by hand prodaces dusty exposures. asses MAsnaucruaaro The most hssardrms dussy sress in ghat manufacturing are lowed in the raw-maamis moving department sod the batch-mixing department. The unloading of glass sand, soda ash, spar, flint, and other materials from bear cos or trucks into storage bins produces dusc. Bean when these miaerials art mechanically handled, dusc it nrocrated. Beech mrting where -the various ingredient* tee drawn from storage bins and weighed preparatory to being trsesportrd to the furnace* also produces dost. 98 Mechanical Engineering POTTEXV MANUTACTUXINO Wtu: has been listed for glass manufacturing also applies to pottery manufacturing. This is true even when a slip system is used. In addition, the grinding and lain-firing operations are important sources of dust contamination. RNAMBLING AND SNAMEL-WAXS MANU?ACTUEINO In the preparation of enameling material by mixing, grind ing, in either bar or ball mill, blending, and solution-making dust is generated. Spray coating or dipping objects may cre ate a dusty atmosphere through the dispersion of the fine drop lets in air and drying out at the suspended material. The rim ming of articles to produce stripes is a dust producer of high severity. Loading kilns for bring including the operation of continuous tunnel kilns may produce dust in large quantities. In such manufacturing as well as in many others, the transport ing, storage, and handling of raw materials may be sources of dust. TEXTILES This caption also includes paper, linoleum, felt, hair, and other similar types of manufacturing operations. Such dusts are not generally considered as being toxic, but yet a sufficient number of instances have arisen to make it. appear warranted to include them within the scope of this paper. Picking, opening, mixing, blojving, carding, willowing, spinning, and other similar operations produce dust. In linoleum manufacturing the receiving of the raw filler material, such as soapstone, talc, and mica, as well as the storage of these materials and their handling during process work, may produce dust. Both in hair and in hair-goods manufacturing, the dust may also in clude the spores of anthrax and the origin of such contamina tion may be particularly prevalent in the blowing and curling operations. METALLIC-POWDBE, MANUTACTUEINQ Where a cupola is operated in connection with such opera tions, certain exposures previously listed may be found. In stamping the metal, dust may originate. In coating operations dust also occurs. Where an air-float method is used for the separation of fine particles from large, dust may be ex hausted into the atmosphere of the place of work in copious quantities. MISCELLANEOUS EXXKUUS There are certain exposures where a material may exist in the form of a dust, a vapor, or possibly a spray of fine droplets. The correction of any exposure of this type requires recognition on the part of the engineer of the material to which workers may be exposed and a determination of the point of origin of such material. A few miscellaneous exposures are discussed in the following paragraphs. Exposure to Mtrcuey. Exposures to mercury may occur in the mining of the ore, the reduction of the ore, and in the amalga mation of gold ores. Exposure is also found in the manufac ture of thermometers, vermillion, and other dyes, the felt-hat industry, the treating and handling of furs; incandescentlamp, radio-tube, and other electrical-apparatus manufacture; explosives manufacture; and laboratory work, including photo graphic and research laboratories. The exposure may be from the dust of the salts of mercury, the generation of fine droplets of mercury together with dusts of other nature, and the vapor of mercury which is generated at high temperature as well as small amounts which may be given off at ordinary room temperature. Exposure to Chromium. The exposure to chromium is usually found in the generation of the dust of the salts of chromium. There are certain processes in the manufacture of chromic acid and chromium salts from chromium ores which produce dust. The manufacture of paint pigments containing chromium, yarn dyeing and calico printing, the use of bichromates in dye prepa ration, the chrome process of leather tanning may also hare dusty operations. In electroplating with chromium many fine droplets of chromic acid may be thrown into the air by the bubbles of hydrogen disengaging at the surface of the liquid in the electroplating tank. Exposun to Benzol. Exposure in the case of benzol is usu ally due to the vapor of the material. The operations of its production, its use in artificial-leather manufacture, in de greasing operations, and in others may result in an exposure. Information may be found in the report on benzol which was published several years ago by the National Safety Council. Exposure te Ltad. As lead is used in widely varied operations and in widely varied forms, it would be relatively impossible to list all of the operatioas which might include an exposure. The exposure usually exists in the form of dust of the material itself or its compounds or in the form of fumes which may be generated at points where the material is handled at tempera tures above its melting point. Dusty operations may occur in lead mining, laid refining, lead smelting and sintering, the manufacture of plumbers' supplies, foundries, battery manufacture, both storage and dry, pottery operations, glass manufacture, certain printing trades, rubber-tire manufacture, and paint manufacture. In addition, dusty exposures may occur in the chemical-manufacturing trades which involve the manufacture or use of lead or its compounds. Exposure t* Arsenic. Exposure to this material may often be found in the dusty operations surrounding the refining of copper ores and the manufacture of insecticides containing arsenic, either in the form of the oxide or other salts. Exposure to Radium and Radioactive Substances. The exposure to this material while not by any means general has been recog nized in isolated sections and attained for itself relative promi nence. The exposure may exist in the inhalation of dust from radium-bearing materials or the exposure to and the inhalatioa of emanations from radium. In general, this exposure is pro duced in the mining and handling of radium ore, the refining of the ore, the collection of radium emanation, and the use of the material in producing luminous dials for watches, docks, and instruments. CONCLUSION One should not necessarily conclude that every operation listed in this paper is an absolutely dangerous source or point of origin of a toxic dust. It should not be a foregone condusion that the operations listed in this paper indude all of the possible sources of toxic dusts. The operations discussed, however, are typical of those where known cases of exposure have occurred. To the engineer unfamiliar with sources of air pollution, even in the so-called non-hazardous industries, the listing may seem far-fetched and ambiguous. It should not be assumed that an exposure listed in this paper is prima facie evi dence that trouble is inevitable, but to an engineer interested in protection against the more important sources of air con tamination by dust generation from ordinary industrial pro cedure, the listing will provide a basis upon which he may work. All in all, it is best for any engineer to proceed upon the basis that any dust of any type in any concentra tion creates an industrial exposure and to suppress the dust at its origin. CITY OF Cinfjnfltu-t,' AFFIDAVIT . OHIO, TO WIT: BEFORE ME, A Notary Public in and for the State of Ohio, personally appeared ffllfoA C _________________ , who stated under due oath of law as follows: I, Hb. e,cv_l am a librarian for the (name & address)Tuhlt'^LiLr*.^ &-f Kn.*i< ilan Co Ot^Y ( Hi*0 3. The pLCM Library contains copies of fi[o.fiWxn I wl4i n(tari ft cj, m. cil cj il z> < n <j_ ^ The pages attached hereto are true and correct copies from McLlwufsl fl-Kcj |]q\ou\4 (I c?-T (theka ntcuLl^ks-itl44r-)n4t AIaw- Z' H e^. / 3P> a l J )9 .~? *9.which is maintained in the This document is in such condition as to raise no suspicion concerning its authenticity. It was received on nl 193 *1 by the PlC ~tf Library and is presently maintained in the iP Cl <^6l z < (L __ zLku> rPa, Section of the (name and address). Pi 0 H _____ Qi rtfcf * ;___f).U 0 d ^-rte<e.-h QO'lf t-- STATE OF OHIO COUNTY OF {(MtL-ro^ tflV fo$\ C \) iAU _, Affiant, being first duly sworn, deposes and says: That the foregoing statements are true and correct.