Document pp50jJM0rypRDYr3KRpb6mEEa

FILE NAME: National Safety Council (NSC) DATE: 1929 June DOC#: NSC432 DOCUMENT DESCRIPTION: NSC Health Practices Pamphlet - Dust DUST Health Practices Pamphlet N o. 4 Published by National Safety Council 108 East Ohio Street, Chicago Thit pamphlet'it a compilation of experience. It mutt not be confuted tcith Federal, State or imurance requirementt. /< /79 General Statement There is a definite relationship be tween dust and occupational disease. In industrial processes, dust may be responsible for the occurrence of va rious types o f intoxications (lead pois oning) and infection (anthrax). T he chemical composition o f dust may be o f more importance than the weight and num ber o f individual particles compos in g i t. T h i s exposed" to mineral, metallic, sugar, flour, aniline or other dusts. Numerous studies have been made o f the effects o f smoke and soot upon the health of workers by anti-smoke commissions. The results show, an apparent relationship between the smoke nuisance and diseases o f the, respiratory organs, especially pneu monia. to lower the social status and selfrespect of work people." Effects of D ust Inhalation . Zenker has applied the name o f pneumonoconiosis to the various forms o f diseases o f the lungs caused by the inhalation o f dust. It represents tw o words, from the Greek which mean "l u n g " a n d "d u st" The kind o f dust inhaled determines t h e s e e m s particu larly t r u e o f dust containing. ty p e .o f pulrao n a r y lesion s. However, there poisonous s u tv 's s t a n c e s and i s ' o n e patho lo g ic a l process * ri nf ec t i o u s organism s (lead, ^ which underlies "&|5all f o r t e s o f anthrax, etc.). fating disease and Apart from its |f-^this consists of a r e l a t i o n to respiratory dis ^^fibroris'ora re-' `. placement o f the. eases, an impor- y elastic tissue, of tant r o l e is ' ' tSe lungs by that' played by dust . o f an unyielding in the irritation scar tissue. o f the eye, ear, ' Probably the nose and throat; m ost important th is is m anifest kind o f disease ed by the undue o f the l u n g s prevalence caused by the o f chronic in Courttar IfctrepoKtaa L ib Ins. Co. inhalation flam m atory, con ditions o f these Figure 1. Smith-Greenburg impmger taking tample of air near lead catting operation, ` * .*'< ' `v- o f dust is that .w hich has been . organs in various industries. It is also Certain in.jurious effect_s o f dustsV nam ed "silicosis" 'T h is disease is seen in J fie frequent occurrence o f cannot be questioned. This is further^ cau sed b y breathing air which contains the ulcerations o f the nasal septum in ' emphasized by the study o f tuberou^>:arelatively large amount o f free silica.., X ^ ^ certam workers. Vrf Flour and sugar dusts, usually con* sidered .harm less, may be converted losis in relation to the dusty trades,'' It is fortunate, however, that only about 25 per' cent''<M. dust inhaled The chief-form s in which free silic^C is encountered in industrial, processes are crystalline silicon dioxide, granite, ' ,, into lactic a d d in the mouth, and actually reaches, the Jungs. According quartz and sandstone. .^' thereby increase th e yfrtdence o f to Lehmann and other investigators, There are tw o tentative Standards ; ^ germ s; this is illustrated by-the undue : the bulk o f dust that may be inhaled is ea stin g i n ' regard ^ prevalence o f -dental decay and pneu a u t h o r o r.s w l-. quantity o f free m onia in som e flour and Sugar work r r . dust! :: ers." ' . The South . Skin irritation is stxnetim es. pro Haldane says that, in addition to lished the upper duced by a combination o f dust,'sweat the trwhaniral irritative and poisonous ' tween eight and heat, particularly among persons influence o f dust, `I t inevitably .-tends' ; -per cubic foot Copyright, 199, National Safety Council. *j si- r - v HEALTH PRACTICES PAMPHLET NO. 4 Smokes--from 0.1 to 0.001 m-mm. in diameter. Although size of particles is import ant, the quality of the dust is equally of moment, fo r there are both nonirritant and Hritant dusts. A physio logic classification of dusts by Dr. C. K. Drinker is apropos here: I. Poisonous (from a chemical stand point (a) Lead, mercury, arsenic and others. This kind of dust is taken up by the liver after ab- , sorption through the lungs or - gastro-intestinal tract II. Non-poisonoue (a) Organic--mainly the vege table fibres, such -as cotton, jute, hemp, etc. (according to . Landis these do not produce lung fibrosis). ' - (b) Inorganic (mineral' dusts) 1. Non-silica-containing sub stances, such as coal and lime. (No fibrosis); 2, Combined silica (silicates) --no fibrosis. ^ Orothosilicates--clay, hfetasilicates-rtalc . Trisihcats--feldspar. 3. Harmful siiica (crystal- Going out the same route as that, by which entrance was gained. 2 . Removal by the blood stream. 3. Removal by the lymph stream. The stages by which a particle may be removed from an alveolus are as follows: 1. By phagocytosis. This process is accomplished' by certain kinds of cells which are given off by the blood vessel walls, when an irritant comes into that neighborhood. These free cells move into the alveolus or tiny' lung space, and surround or engulf the' foreign particles. The phago cytic cell then moves through the walls of the alveolus and probably back into the lymphatic circulation, 2. The phagocytic cell may then be carried into the lymphatic drctila-V: tion and to the glands at the roots of - the lungs. This may happen within r-; .v 24 hours at first, but later, collections :-i-T'S of lymphoid material may offer ob- '.V. struction to such migrations. These nodular collections, may show- as dense spots in an X-ray film. Later... on they may become fibrous and :-p<'cC ' show as- dense strands in a film. . The .phagocytic cell may m&ra back^into the blood stream _ ' thrbfigwh.ft*heV.*blood vesos-e*l waU.5 .Service in its research at B am , V t th o ^ 'o ll . found that the upperJunit wass. some-,. . jjj th e'pountry. O n "eiraS lwiohnesreobf eptwaretiecnletseap-earmciuttbweiccefnStykmi:l- ;. ,_- . -wj o f the-piguKatati^. b e particles o f .carbon-!^ in < & e ;;.J i ^ is probably d< ^und^y^f p en d en tl^ ^ ^ tb e difficulty ofnbsorp-:* kinds - -tin' r tii^ ' tban upon the -massive T hese upper lim its o f safety gre ob o f 2ust>: wThe. fin...e:r 1t viously dependent upon the percentages , _ _ je.a re re _ _ S 'tm sT lie^ ^ ^ ,T n illustrating anim als o f free siuca found in the atmosphere chanjge^the c o a r s e r .fj^ d usually caused ijfe-^reathe.carbon d u st The' ^ under consideration. having been entrapped in tfie nose or lungs showed yd efin ite clearing after a Classifications of Dusts the upper jiortion o f the resjxratory^ ^ f tract and usually later expelled by coughing. It is likely that particles ' T he size o f dust particles has much over 2 micro-millimeters in size do fttj to do w ith whether or not they w ill not reach the lungs. cause trouble in the lungs. T he larger Normally the structure o f the wind-^iv particles m ay be neglected when con pipe and .file bronchial tabes , is a d e -$ sidering th is p o in t T he words ``la ig e " ^ fe h str c :D u rtfe and ``small" are used here in a relafcve,g'm u c^ sense, for aU o f these jarticles are er-?lSv^fbid p i i ^ ^ w fhe. ^ 'coed in gly sm all. '.' For instance, the ^ o T th e sniim hsuM_pfithe ^g&xtides tiiat scrp significant in consid- ir^ '^ o f ^ h ^ ^ i g o in g fiie production o f a fibrous re- r ix u n ^ ^ ild is ^ ^ ^ Faction in the lungs range in size from ..' the &fffajEe:iinm g^ahd , p i -to 0 ^ nvaxMnfilimeters in diameter X d e fe n se s'fin is le st'to -fh a-. is the'equivalent .^ cim u n stm ceis not wir1-^ n.inch). G fl)b s.^ ^ ;d iro n ic.M ^ to arding^te. itoty passages ;ta s than ' lOm-mnt 3n: di- m-mm. in' ui- DUST 3 few m onths; this was not true when silica, was breathed; probably it acted as an irritant. T his caused a circulatory disturbance by which the particles be came coated w ith serum. Because of the lack o f absorptive power of silica particles, the consequent circulatory disturbance and production o f serum, the particles o f silica were not taken up by the w hite blood cells and removed from the lungs as had been the case with carbon particles. This behavior of different kinds o f particles was re sponsible fo r the working out o f th theory as stated. Probably the best analysis o f present day opinion with regard to the effects o f dusts upon the human body has been made by D r. E. L. Collis in the report o f the Fourth International Medical Congress on Industrial Accidents and D iseases: 1. Dust particles which have reached the alveoli are there engulfed by cells originating from the epithe lium lining the alveoli and are car ried within them into .the lymph channels of the lungs. t. Particles of some kinds of dusts , . are more, readily engulfed than those of others. Organic particles, such as coal, are'most readily taken up, and particles of silica least read. ily ;. but when, certain cells have been, as it were, educated in the function of absorbing dust particles through the presence of, say, coal dust, they more readily take up par ticles of such substances as emery, carborundum, and silica., 8. Particles of certain dusts, such as carborundum, when engulfed and carried into th t lung tissue, remain inert, and produce no reaction. 4. But silica particles slowly dissolve within and react chemically upon the cells containing them, causing cell death and mummification. 5. The dead, mummified cells collect ' in and block up the lymph passages and glands; here they disintegrate and distribute the dissolved silica, which reacts with the surrounding tissues. 4 ' The final result Of the'reaction is * the formation of scar tissue as a solid mass of material which in .'time replaces the normal alveolar structure of the-lungs; the condi tion'is'ode of silicosis. -7 Afl '.the various- stages through . which silicosis advances can be de- tected. by X-ray photography. .8. "T he same results follow whether . fine stticS dust be artificially placed -='l in. the body o r soluble silica be in: jected, but m the latter case the - . disintegrating, changes take place . more rapidly. 9. Dead tissue so caused forms a me- -.drum in which tuberculosis germs - '*readily flourish. - .. ' = Figure 4- Lefti Bmith-Qreenburg Impinger. Rightt Drinker electric precipitator at Indeutrial Laboratory, Metropolitan Dife Insurance Coi 10. When soluble silica is introduced into the blood stream it reacts with liver cells, causing scar tissue there, and also in kidney cells. 11. Statistical records indicate that Suspensions Of freshly generated zinc pride fume .(particles of about 0.4 micron) of Kadox (a zinc oxide powder' with particles about 0.1S micron) and ;*bf 'marble dust (particles about 0.3 to 5 microns) were set up in a 1,600 cubic Bright's disease as a cause of death ^fPot gas cabinet is unusually prevalent among certain., .The subjects; seated outside the cab- occupational groups exposed to nil-' -inel/ inhaled the air from within .and ica dust. ,i&:^exhaled through an. electric precipitator It. Clinical observations have shown -: ^ i n t o -a 125-liter spirometer. - that (a) in many persons who hayc A?! The percentage retentions for aft three been exposed to silica dust, f o r . . suspensions averaged 55 with standard period sufficiently long to enable the--' . . deviation of 9A. T he'concentrations in- - dust to gain access to the lungs, the .haled varied from shout 50 to 450 mg. silicotic process continues to ad per cubic meter, the exposures from five vance -after complete withdrawal to forty minutes, /and the rates of from exposure; (b) the silicotic - breathing from 6 to 1 respirations per process may progress to fatal.termi minute. \ nation without the effect of any intercurrent disease; but (c) a sili cotic patient is particularly liable to. Preventive Measures fall a victim to tuberculous infec tion; (d) tuberculous infection in a lung containing silica particles hur Kober discusses this important phase o f the dust problem under six headings: ries the process of silicosis; (e) pulmonary tuberculosis in silicotic subjects, (depending upon the amount of scar tissue present,) runs an unusually rapid and fatal course; but (f) when silicotic per sons are protected from exposure to tuberculosis infection,, the occur- . rence of tuberculosis among them is minimized; hence tuberculosis in such persons appears .to result from fresh infection during adult life; (g) tuberculosis infection from sili cotic persons seems to be less potent . than- usual for infecting nonsuicotic persons. 1. Prevention of Dost Formation. A number of important processes in industry can be properly con trolled by the application of oil, sprays of water or jets of steam. This method of protection is espe cially applicable to the metal, lead and pottery industries, rock drill ing, mining, blasting, stone-crush ing, cutting and grinding. Several investigators have em phasized this method of control, be lieving that proper usage and adapta tions would remit in the abolition of some of the more severe diseases arising from exposure to dust How Much of the Inhaled Dust ; Is Retained? Drinker, Thom son and Finn have noted in an article published- in the Journal o f Industrial H ygiene for Jan uary, 1928, the follow ing effects: Another important application of wetting.processes is .prevention of . . disastrous exploskms of coal dust m - mines. 2. Prevention of Dust and Fume Dif fusion. Protection is accmplished-jmder.; this head hv the enclosure of. ma- HEALTH PRACTICES PAMPHLET NO. 4 chittery or operations in air-tight cases. This method, however, sotne times gives rise to great difficulty because many processes cannot be wholly enclosed and still be effective. 3. Removal of Dust and Fumes. Much has been accomplished by . devising systems of mechanical ex haust ventilation, which ' remove dust and fumes at the point of origin. Various codes have been invented which lay down specific rules and definite provisions for removal of dust and fumes by the proper con-struction of benches, tables, and other furniture with reference to hoods and other section apparatus. A very important point in the ar rangement of this type of protection is that, provision should be made to ' carry the dust and fumes away from the face of the worker. I t is not within the province of this work to give details as to the working out of various exhaust sys tems. (See Safe Practices Pamphlet No; 32, "Exhaust Systems.") 4. Collection of Dust and Fumes. W here poisonous fumes and gases exist, methods of collection consist of condensation, absorption by water or chemicals, destructive distillation by heat in a closed vessel, combus tion of gases that can be burned, and finally, by the discharge of gases into the air above the working level. Valuable by-products are also re covered by condensation and ab sorption. An example is the value of blast furnace and coke-oven gases, which are used for fuel, for heat and power, ' and also sulphuric add fumes which, are collected and made into sulphuric add. Certain dusts which have no espe cial value can be passed through a tower and precipitated'by means of fine water spray. Where the dust is of value, i t may be collected in suitable tanks under water- for ulti mate recovery of constituents. , Large particles of dust are usually collected by a so-called cyclone sepa rator in which the dust is collected by centrifugal force; Mechanical filtrations have been accomplished by the use of mechanical knocking devices, through textile fabric or wires Of different meshes. Electrical predpitation as devel oped by Cottrell has been found effident in predpitating and collect ing certain kinds of dust 6. Masks and Respirators. I t should be borne in mind that masks and respirators are usually uncomfortable to those who wear them. There is an endless number of these devices upon the market . T he best respirators so far designed are intended to filter out dusts and fumes by means.of sponge, cotton," wool, gauze or other material. Most of these are .effident for a certain period, after which they become clogged and need to be replaced. Masks are more reliable and afford ' a greater amount of protection under - ordinary conditions. (See Safe Prac tices Pamphlet No. 64). Kober states that working conditions should be so nearly perfect as to obviate the use of respirators. Until this is accomplished, he says their employ-, ment should be encouraged. /6. The Cleaning of Workshops. It is impossible to set up exact -standards which will apply to all the tobacco smoke; most of the silica particles were 1 micron in dia meter or four times the diameter of the tobacco-smoke particles. 3. As dust particles most injurious to miners, stone workers, and many others engaged in dusty trades are about 1 micron in diameter, res pirators, if worn, can prevent a con siderable amount of dust, but not all of it, from being inhaled. 4. Although the laboratory study has shown that most dust respirators are not highly efficient in removing tobacco smoke (very difficult to arrest) from air, a filter that re moves 50 percent of the tobacco smoke from air flowing at rate of 85 liters per minute is very efficient in restraining the ordinary dusts encountered in industry and also the smokes, (such as those from burn ing wood and other carbonaceous material) that city firemen .en- .; counter.. Hence, the Bureau of .- Figur B. Microphotograph of talc dust; on scale division equals 1 m-tnm. Mines adopted a 50 percent effi-"*. ciency test against tobacco smoke, as a standard requirement, (in ad--* dition to others) for the approval of respirators or gas masks designed to afford protection from smoke ' cases and all industries. I t is also or dust - ^ wdl to emphasize the fact that.no amount of ventilation can do away with the necessity for. frequent and systematic cleaning of plants. Shops should be .Swept daily after work . has ceased, using damp sawdust'or other material and having windows open widely. Some industries use a vacuum system for cleaning and dusting and. this should always be encouraged. Under certain conditions, cement floors made with a considerable in- ' dine for drainage have been useful in fadlifating washing. . Feather dusters ordinarily do not remove dust, but merely redistribute i t Moist doths have been found ef ficacious for removing dust from : surfaces of furniture. "Dust oil" has not been found effident, as us ually it only allays the dust and does not remove i t 6 Because the laboratory tests of the i dust respirators were severe, ; the * low efficiencies given do notvindi-. cate the general effectivenen'lo tU these respirators under all industrials conditions. Much of the dnij*-^ countered m industry is kss.mffict`r to arrest; the overall efficiency ? th respirators in actual service/nay thus be correspondingly higbeif The tests therefore show that -asp rule the respirators are of,m ` value in removing injurioul7.d from inspired air. ' 6. The discomfort caused by respira tors' covering the face--the i e i generated, the irritation of thieji* ' in contact with the respirators, _ the resistance to the on.of w if~ ` breathed--re the most seriocs^Es-jji advantages of respirators. The re- -sistances of industrial dust respirators to air flowing at 85 liters per ; Dust Respirators minute were 0.25 to LS inches of water. The Fogler flat felt filter Through the Bureau o f M ines, S . H . had a resistance of 2JS5 indies and the gas-mask canister 3.6 inches. Katz, G. W . Smith and E , G. M eiter A man wearing a gas m ask '^ conducted a study on the construction "* work hard only about half an? and filtering efficiency o f dust respira then the extra effort caused i^ tors. The condusions reached were a s . - resistance to breathing competsLim follow s: to -stop to rest or greatly -redo ' his exertion. \c5fc '- 1. The effidenciesj.of . industrial dust ; The resistance of the dust respira- respirators in:. restraining tobacco ;tors, although causing some,'dis smoke range from 5 to S3 percent comfort, does not seriously.inter when the air is passed at a rate, of fere with a man's exertionsvun* 82 liters per minute. A gas-mask the filter becomes dogged w ig ra canister with -tw o filters of ab posited dust and the reristancgoi sorbent cotton showed S3 percent "f responding!/ increased. Tbcmlt efficiency. The Fogler flat felt filter^- ,;. : . must then-be. cleaned, or freex* was most efficient, showing 97 per,-, dust, or be<rplaced b A f cent s. Filters of various fabrics, in 2. The efficiencies against silica dust chesedoth, canton -flannel, un-- floated in air, range from about 9 , : bleached muslin, dosdy - woven to 70 percent for dust respirators,??^'^--- -bleached muslin, filter paper,'and or about twice the efficiency against - . absorbent cotton, all made for test  purposes so as to expose exactly 100 square centimeters of filter area, were tested against tobacco smoke and against silica* dust in air flowing at a rate of 10 liters per minute. Each material was tested in a single layer and in multiple layers. Results showed that each layer of fabric (in effect) removes about the same proportion of smoke or dust that penetrates to it before the filters become clogged or altered by deposits of an arrested material, such as silica dust Consequently, when the efficiency of a single ply of a filter is known, the efficiency of any multiple ply filter of that material may be calculated. 9. Silica dust clogged filters rapidly and increased the resistance to air flow, but some materials were more resistant to clogging than others. T he dense filters of paper or closely woven muslin clogged most rapidly; filters of loose texture like cheese cloth or absorbent cotton clogged the least 10. The efficiencies of the filters were increased by clogging with dust until eventually many filters'gave an efficiency of 100 per cent 11. Tobacco smoke did not clog filters, ' and there was no increase in effi1cicncy as the smoke was deposited. 12. A few tests were made with woolen fabrics, but they proved to be no better as. filters than cotton fabrics of similar texture. IX The efficiency of the filters de- . creased somewhat with an increase in*the rate of air flow. Sometimes a cotton fabric with a nap showed a decrease after htmtid smoke had wet it and the moisture had caused the fibers of the nap to adhere to gether. 14. The resistance of the filters to air flow increases in proportion to the number of plies of fabrics after the first ply. The first filter layer shows a somewhat higher resistance than the additional ones. 15. The resistance of fabric filters to air flow is. very nearly proportional to the rate of air flow. 16. Air filters of high efficiency can be made with a sufficient number of plies of material that has a low . efficiency p e r single ply--cheese' doth, for example. Such filters have less resistance to air flow than equally effident filters made of fewer plies of the higher-efficiency' materials, such as closely woven muslin. 17. The thicker filters of loose-textured material -clog lest rapidly than equally effident filters composed of fewer plies of tightly woven ma terial. . -. IX A new type of dost respirator was designed and constructed accord ing to the principles brought ont in the tests. This respirator consists of a large filter -of canton fiannd m ade into a cap or turban for the head. Air filters through the can DUST ton flannel to the interior, passes through a check valve, and is then conducted through a rubber tube running over the forehead and be tween the eyes to the nose, which is covered with a small rubber nose 5 In mining and in other industries efforts to prevent the formation of dust and its distribution by the air by tho use of hollow drill steel and water, and by sprays on the under cutting machines should be con tinued. The National Safety Council has pre viously called attention in the reports given, by A. L. Watson, Chairman of the Industrial Poisons Committee (at the Eleventh' Annual Safety Congress in 1922), to desirable qualifications in respirators: . v7-- 1. Lightness in weight 2. Automatic adjustment to facial lines. . 3. Comfortable contact edges Which will not irritate. S. 4. No obstruction to vision. 6. No interference with wearing gog gles. . No serious resistance to breathing.- ; V. Relief valve that will not clog. - . fc*V <* : ** . No interference with chewing and spitting.. ' , ya. Relief valve-placed .so a s'h o t to . y ^ S 'blow dust in dyes. lOi : Headbands durable and easy to ?;-(.* fasten..- /* ' '*- ' * **' * It. Inflation valves easy to operate if contact is pneumatic. 12. Durability of parts requiring adjustmeat _ U 13. Little..attention required. STATION 5 More recently Barreto, Drinker, Finn, and Thomson'tested the efficiency .o f dust masks and respirators and em phasized the following points : Lj _ i i i . . ~Q f f Jo J ff t o t s GJZE JN M iCRA / Figure 9. Graph o f particle ebeoe fa . three eamples o f dusT, o ftor record ing microtoopie count. , . cap. At an air flow of 85 liters per -minute the efficiency of this respira tor was S3 par cent against tobacco smoke and 93 per cent against silica dust 19. -The data, presented and the -prin-. r ciples ootlmed may aid manufac- ' tnrers in improving dust respirators. .20. -Although the use o f respirators should be encouraged among workers in dusty industries, a respirator cOtttr not be considered..a'final safeguards. 1. Masks for protection against dust and fame particles must be provided with effective filters, preferably of a fibrous nature and with large cross-sectional area. The materials used in gas masks for protection against poisonous gases are ineffec tive in removing particles of dust and fames. 2. The effiriency of masks of large or small area can be very greatly increased bp plugging the surface meshes with a freshly generated, finely divided fame like zinc, mag nesium, or aluminum oxide. If the j filtering area is small, _plugging quickly increases the "resistance to i prohibitive figures:.but masks with . large area (800 ttrl 0 0 sq. cm.) -" . . can be p lag g ^ ;f05give perfeet.proj? tectioa again#, finely divided an,, fume and over 97 per cent against tobacco smoke. >A t the same tune, . t h e resistance .toiuir flow can pc kept bdow-30 m itt"Of waterj>res- | sure measucediat 85 Titers a mwtjte. ; HEALTH PRACTICES PAMPHLET f Other Methods of Protection Dr. R . C. W illiam s calls attention to the follow ing general measures for pro tection against dusts and fumes: 1. Industrial Law The foundation of industrial hygiene and sanitation rests on in dustrial law. The history of the control <fi industrial hazards is the well as does the employer. Protec tive measures may be required by law and provided by the employer, but if the worker does not under stand the necessity for their use much of their protective value is lost Wholesome, common-sense education is the means by which the need for intelligent use of protective^neasures is impressed upon the workers. 4. Scientific Study of Industrial Haz ards 3. Filtering. 4. Scrubbing. 5. Electrical precipitation. S ettlin g usually produces a pilingup effect so that the counting of sepa rate particles is impossible. C ounting. An efficient jet dust counter has been devised by Owens. The correct basis of industrial law rests on comprehensive scien tific understanding of the hazards that are to be controlled. The proper control and prevention of the health hazards of industry and their effect upon the health and physical condition of the worker can be obtained only through care ful and thorough scientific investi. gations. The maintenance of ade quate industrial sickness records by employers in order to determine the cause of sickness among workers, and to gauge' the efficiency of measures used to reduce health hazards is an important part of the study of industrial hazards. F ilterin g has long been used, e s pecially by the Bureau of M ines; differ ent substances have been used for the filter, such as cotton, nitrocellulose, glass wool, paper and alundum crucibles o f the insoluble type, and sugar as the best example o f the soluble type. The difficulty with filter collectors is that they clog and resist the air flow, there by preventing the possibility of getting the true quantitative dust content o f the sample being tested. Scrubbing m ethods (so-called be cause o f the admixture of the dust ,335' particles with water) are much used Dusts as Explosion Hazards because o f the cheapness o f water. The Drinker collector is an efficient kind The National Safety Council has o f scrubber collector. ^ .ca lled attention to this matter in its S afe T h e-U n ited States Public H ealth. ^ P ra ctices Pamphlet N o! 34 on the sub Service and the U . S'. Bureau o f M ines. j e c t , "Industrial Explosion .H azards/' have recently made use o f an apparatus'*-:. A .partial list o f flammaMe. dusts i s . i-n their *fie,l*d/*w*or*k., ,,call*ed! ann imping^r. r* -given here: . * ` ... B y means o f this instrument- the aif-'is. Sugar 05 Flax ' impinged at 'a high velodty on a wet Dextrin/.. Cotton surface and then bubbled through a - Starch? CeUmoid . layer o f water. Large volumes o f air . Cocoa *:; Coortccr MetropoEtaa life lot. Co. Flour y Gum Paper can be sampled and the efficiency has Figaro 7. Impiagor ip m < for Urminatio* o f fame* from a load pot. Graft V Maize ' Tanning bark ' Cork been found to be between 98 and 96 percent, according to conditions. Fine wood dust Bronze Fertilizer Iron - E lectric precipitation has been history of the enactment of indus Charcoal trial laws. Industrial laws must be -Coal - Hemp Oakum practiced for some time, the most not scientifically sound. Fundamentally, Lampblack Powdered drugs able example being the Cottrell precipi the law is for the protection of the Sulphur Aluminum tator, used extensively to collect smoke. worker, but, on the other hand, _in Metallic dyes Antimony' A modification o f the Cottrell device forming such a law the effect on in Oat husks dustry and the cost of production Malt. Hard rubber Powdered milk represents the best type o f electric pre must be considered. . The elimina Spices /Zinc cipitation collector and one from which tion of all dustiness in the work Leather -the particle size may be studied, as well processes where there is a dust Jce milling /Magnesium - as th e chemical constitution o f the d u st hazard, may be desirable, but there Alfalfa . .. -Y Soap powder . . is no scientific reason tor such a -Wqal vV Y Shellac W h o e v e r ' there is a noticeable requirement if the dust itself is not - Y i am ount o f dust produced in a given a specific poison. ~ ,, , . ' "ix tndustrial prooess, the important steps S! 8. Law Enforcement ' Methods o:v D u s t C o lle c tio n 'fe in 1the investigation o f the dust hazard '^ 1 'Industrial laws are valueless un- /> t o t ' S t u d y - ' f w o d i b i i . . - less enforced. The. method of law enforcement in industry is usually Methods by which dust may be col The quantitative estimation of crys through factory inspection and the lected and studied as to chemical con-. , talline ancon dioxide In .the sample actual, checking up of the efficiency tent size 6 f particles and amount j>er - , . of protective devices. Competent:; of air breathed b.y.w--orkmen. * insures ike.coiH-- unit o f air, have been the cause o f much - v t_r_ot__o_f_m__d_u_s_tr_i_al. h__a_za_r_d_s_"_a_n_d__t_h_er:esearch'- and . inyestigati^^isT h<ffle? - maintenance of, acceptable -sanitary -. midhods may hie briefly summarized a s ' . , y\ ' follow s: y V - - Y Y - n eys' to realize the danger ot cerfainhealtli hazards as ^ z."--KV/q.V.vr & 'i ......" - DST Outline of a Typical Dust Study The United States Public Health Service has recently published a mono graph entitled "The Health of Workers in Dusty Trades." T he method used in this study is here outlined: 1. Physical examinations for the pur pose of determining general physical conditions. The data from this procedure gave important physical differences; the industrial rating of the individual; the group to which he belonged; and lastly, aided in the selection of cases for special study. " 2. Special physical examinations to de termine the problem of specific disease of the respiratory system. This entailed a special study of lung pathology resulting from dust exposure. i %* V-'- 3. Sickness records of the nature and severity of disabling illnesses. These record cards showed all ab sences from work lasting two days or longer. Diagnoses were made in all cases. Figur 8. . . Court*? Metropofitaa Liie 1 s t Co. [UctriC precipitator in eu* for'termination of lead fu a u i from . . . . catting o f brows. t Occupational environment Chemical and petrografifitc an alyses of all dust samples. passages other than 7: Inhalation contain free espiratory diseases ous reaction. icral dusts Which associated ISft, `TncumonOconiosis: A Summary of .Present "Knowledge." Dr. E. L. .Medical Journal of Australia, Sum m ary. an excess of tissue formation, an excess which; a direct relatiott ft.im.,W^jeri>&^^qrtiind D r. Edgar L . C ollis calls attention to the follow ing points w ith reference to exposure to d u st: to the amount In general, di injurious as tion differs silica p r e s M t . ^ s o n - i i*4ppear to e n o r | ? `.***81 chemical oompomthat of the^buman 1. Inhalation of all forms of dust-is body or from elements -which ::. accompaniedby diminished power of the body is chest expansion. This .patfohlet was tw iites by Dr. 2. Diminished power of chest expansion BIBLIC IAPHY C. 0 . Sapjnngton, Director of the Di so produced is accompanied by high vision bfin dustrial Health, National blood pressure. "Industrial Health," Kobe*- : and Hayhurst P.^sBlakistofl's Son and Safety Council, Grateful acknowledg 8. Animal dusts (apart from the pres Co* Philadelphia, Fa. ment for., suggestions is .made to Dr. ence in them of disease germs) when "Masks and Respirators for Protec C.-E. A.W indow, Dr. Hobt. S. Quinby, inhaled, produce relatively fewer effects than do vegetable and mineral ' tion against Dusts and Fumes." Dr. Otto P. Geier, Dr. C. F. N. Schram, dusts. Barreto et al, journal of Industrial Dr. Loyal A. Shoudy, Dr. Wm. A. Hygiene, #36-, January, 1927. Sawyer, Dr. Lome E. Hastings, Dr. 4. Vegetable, dusts, when inhaled, tend 3. "Studies on the Industrial. Health Volney S. Cheney, Dr. Emery R. Hay- to produce a type of chest affection Problem--II--A Review best described as asthmatic. Methods S s a -lu S S Smy ^ ? r - ^ r ` 5. O f mineral dusts, those composed o f . Dust"- Dr. U .S.P.H .S. Murd Grntmrg,': R- Crotvder, Dr. Wade calcium salts are least injurious. Inhalation of mineral dusts which do . "DustRe* tion and Their fCheney. M r. J. M. Walts, Mr. S. E. not contain free silica tends to pro Smith and duce irritation ' of the tipper air ; -T^Mines T