Document Mrk6yz8GDgQJqLM80MEejb0k

STOOI 30 I 3 4 INDUSTRIAL DUST Hygienic Significance, Measurement and Control BY PHILIP DRINKER, S.B., Ch.E. Professor of Industrial Hygiene, Harvard ' School of Public Health AND THEODORE HATCH, B.S., S.M. Instructor in Industrial Sanitation. Harvard School of Public Health and Harvard Graduate School of Engineering First Edition McGRAW-HILL BOOK COMPANY, isc. NEW YORK AND LONDON 1936 II I I I1 i! I ' t1 I i CHAPTER II EFFECTS OF DUSTS AND FUMES UPON MAN Exposure to dusts can produce four distinct types of disability: (1) the pneumoconioses, such as silicosis and asbestosis, are caused oniy by dust inhalation; (2) toxic dusts like lead, man ganese, and cadmium can produce their effect as the result of RIGHT SROtlCHUS .UPPER LOBE RIGHT lUHS-,.* BRONCHIAL 'l RAMUS TO ;t, upper lobi :;*< (PAXTERIAlf I SPOHCHUL RAMUS TO MlDOLE LOSE mi00l~< !s use ; 5SOHCHIAl\ RAMUS ro lOivfR LOBE loner lobe- trachea LEFT BRONCHUS i B/fOHCHtAL RAMUS' TV UPPER LOBE-A-i\ f'UPPER 108E`"j v ^LEFT 'i IUN6 m Fig. 10.--Lunt>. bronchi, and trachea. (After Sobotla and ^/e,V/tirrieA.) either breathing or swallowing dust; (3) metal-fume fever is a temporary malady resulting from inhaling certain metallic oxide fumes; and (4) the allergic reaction or protein poisoning, as typified by hay fever, is the direct result of breathing pollen and other organic substances. In all four cases dust inhalation may be the soic cause of disability; only in the case of toxic dusts is there another mode of entrance. Respiration and Dust Inhalation. The lungs arc nousymmetnea.' bilateral structures encased in a rather elastic cavity, 20 * 'J/LT< iu(u>' fi*' GO CD EFFEL the chest, ant through the trt ^ or lobes and tl per cent larger In the norm diameter and lu cartilage which giv the approximate lev the bronchi and the lead to the terminal as result, of inspira blood and air takes cells and carbon dio The amount of a. with the task perfc rates at which an at Table 1. Taxl* 1.--Oxtcew Co Retting in bed Sitting... . Standing.......... Walking 2 m.p.n Walking 4 m.p.n Slov run .. Maximum exertic * Aiur Hfidr*on tnd H*f The ordinary indr per minute, the hie such as long-distance The inspiratory a: but practically we r required for a comp, pauses that occur at Thus with minute \ at the rate of 100 lit 3S6410 am&ir -- l II > FUMES UPON MAN ur di-lmct types of disability: silicosis and asbestosis, are 2) toxic dusts like lead, man : their effect as the result of LEFT BRONCHUS "Tg ttfOHCHlAL RAMUS' TV UPPER LOSE 'upper LOSE SROKHtAlf HA HUS "* TO ' LOWER . LOSE ` $ 'CU-T^uOWER LOSE (Afirr itoitoua and McMvmch.) (3) metaJ-fume fever is a .haling certain metallic oxide )n or protein poisoning, as : result of breathing pollen .11 four cases dust inhalation ; only in the case of toxic .nee. :. The lungs are notisymi in a rather elastic cavity, effects of dusts and fumes upon MAN 21 the chest, and they communicate with the nose and mouth through the trachea or windpipe. The left lung has two divisions or lobes and the right lung has three; the right lung is about 12 l>cr cent larger than the left. In the normal adult, the trachea is a tube some 1 to 2 cm. in diameter and 10 cm. long tFig. 10); it is fortified with ringiike cartilage which give- it a strong and inelastic character. At the approximate level of the fourth rib, the trachea branches into the bronchi and these m turn subdivide into bronchioles which lead to the terminal air sacs or alveoli. It is in the alveoli that, as result of inspiration and expiration, gas exchange between blood and air takes place. Oxygen is taken up by the red blood cells and carbon dioxide is given off. The amount of air breathed and the oxygen consumed vary with the task performed and with the individual's size. The rates at which an athletic man of 150 lb. breathes arc shown in Table 1. Tabi.f. I --Oxygen Ciivsi-iimov asd Volcwe of Breathing bt Man1 Oxygen consumed at 0"C. and 700 Air brent lied mm. pressure, liters at20*C., liters per minute per minute Resting in bed Sitting . . . . Standing . ... Walking 2 m.p.li Walking 4 m.p.h Slow run.. . Maximum exertion 0.24 0 30 0 30 0 65 1.20 2.00 3 00-4 00 G 1 8 14 20 43 65-100 1 Afur Hendcnon nd Hazard U2A1. The ordinary individual seldom breathes more than 50 liters per minute, the high rates being limited to trained athletes, such as long-distance runners. The inspiratory and expiratory phases are not exactly alike, but practically we may consider each as taking half the time required for a complete respiratory cycle and we can ignore the pauses that occur at the beginning and end of each inspiration. Thus with minute volume of 50 liters the actual inspiration is at the rate of 100 liters per minute and momentarily rather high ^ Ih-jct STOOI 30 I 5 ST00I30I6 DCS7 conclusion regarding la- i' .*ii(mnca from a singii- ,.-::in, Table 2S). :f sputum n:i.-.ii ili.-clinrgc of person* :p,;n-r It has always hern .iiitl i- 'iiffiricnlly .-ni.-itivc - of :i n-.-piralor (page 26S) -charge, diluted if necessary, i by smearing on a slide and miemmeineration technique mary examination indicates ontial if a polarizing micro:- technique that the "silialveolar phagocyte of an lily lie demonstrated." cd w lien samples of 100 or. is healed in a beaker over .tor has been evaporated, are added and the mixture being shaken at intervals; for 1 hr. The residue is ;i incinerated. an accurate case history, tion of dusts in sputum, i hi-tory of recent dust suffices for identification ir dark, even black, before .:ig i- caused by pigmenta'movd by treatment with '.s such as the histologist 'ici'-d. irge examinationsfordust, -t oi tier preventive measKrc'-dom from dust in both -tcK/(J by layman and medvon photographically and .ny person familiar with ha- been demonstrated. - . j j i i I | ' | j j i , _ ; | I CHEMICAL AND M/NEHAUDGtCAL ANALYSIS 165 The du-it in phagocytic cells from human sputum was studied by Drinker iG5i, who was able to identify several mineral.' in the ells and to establish figures of average particle size in phagocyte-. In order to examine du.-t in phagocytes, the sputum sample must lie fixed when fresh, and it is best to make several slides, some 'tamed and some unstained. Stains interfere seriously with the miero-copy of the particles but help one to pirk out the dust cells frmn extraneous matter. Agingof the sputum results in bacterial art ion ujkjii the cells which destroys their outline, and must lx1 avoided.1 The cells from silicotics (coal miners) which we have seen recently contained a great percentage of carbon and little else. Since there is little difficulty in getting such cells from patients with silicosis or with a history of recent dust exposure, more such examinations might easily and profitably be made. It should be borne in mind that the presence of dust cells in human sputum does not of itself prove any lung pathology. This mav be a normal finding and often occurs in the healthy city dweller, particularly if he is a smokpr. But in the case of tinindividual with proved dust exposure, the presence of nunicroudust cells in sputum may help in diagnoses. THE IDENTIFICATION OF ASBESTOSIS BODIES For the identification of the "curious" bodies (see Fig. 15, page 33) found in asbestos workers, Stewart (223) employ-- the billowing technique: About half an ounce of sputum is dissolved in an equal quantity of undiluted antiformin in a wide test tube. This takes from a few minuteto an hour or so. ami is aided by heat (3TC. incubator) and gentle agitation. Two or three ounces of water arc then added and the mixture aliowcd to stand for a few hours or overnight. The hulk of the suix?rnatant fluid is now poured off and the remaining 12 to 15 cc. centrifuged at moderate speed for 10 min. The amount of deposit which come down varies in different specimens, but in any case the whole of the supernatant fluid may be poured off by simply inverting the centrifuge L.ibc. The deposit and the trace of fluid which remain arc thoroughly 1 It is assumed that any person examining the dust particles in sputum or in nasal discharge will familiarize himself with the accepted routine of spiinim examinations as carried out in ordinary medical diagnoses, lie nceii observe only the inciliodi of preparing the specimens and need not 1mruin-, riird mill liaclvniilogieal ur pathological mailers. "1)Y'l i-U '(c-fJ l^s. -felt 396412 1GG 1XDI .STH1AL W ST fluxed by mc.ins of a fine pqicito ami transferred to an albuminized slide, or slide.'). Too much force imi-i ii..i he used in the mixing process or at any previous stage in order not lo disintegrate any dumps of asbestos bodies winch may be present. As a rule the whole deposit' from half an ounce of sputum may lie spread over an area of 1 sq. in. of a microscope slide, or less, and in any cose a thick him is desirable. After thorough drying on a hot plate and (inal fixation over a Bunsen, the film is very gently washed in water, dried and mounted in Canada balsam. The washing in water must be done with the greatest care, as, in spite of the albuminiiation of the slide, the film is very easily detached, especially if it is thick. After washing and (Irvine, the film may be treated with ferroevanide of ixjtassium and hydrochloric acid tu demonstrate the Prussian blue reaction given by the boibcs. It i.~ then dried and mounted in balsam as before. Alternatively the centrifuged dcjxisit may be covered with a small quantity of a 5 per cent solution of ammonium sullide. when the bodies are colored black. Xo ?[veial staining is required, however, as the natural greenish yellow, gulden, or brown color of the bodies renders them sufficiently conspicuous even under the low power. My practice is to examine fihns with the t-iu. objective and 10 X ocular, confirming the presence of asbestos bodies with the j-in. objective. It is necessary to cleanse thoroughly all test tubes, centrifuge tubes, and pipettes after use; otherwise there is a risk of contamination of sub- ><.1106111 si'ccimcns from a |m>itive sputum. Asbestos bodies are detui'ii-trabk- by this method in the great majority of asbestos workers provided they hate any cx|>ectoration. In the older workers, esivcinlly during a bronchitic attack and in the later stages of pulmonary a.-besto-iv bodies are present in profusion, but. even in those who ha\e oniv been engaged in the industry for a year or two. they- may be demonstrable in 'mall numbers. Their presence indicates merely that asbestos dust has lieen inhaled into the lung and that it has remained there long ennugn for "bodies" to form around individual fibers, a period of months at least. It docs not necessarily mean that there is pulmonary (ibrosis. The finding of radially arranged dumps at bodies similar to those demonstrable histologically within the lung alveoli has modi more serious sigiiilicancc. It indicates disinte gration of 'living tissue, either by suppurative lironehopiieumoma or In tuberculous CHseatmu. nml may lie taken also as presumptive evidence of an underlying h'Ih-'Lmsis, - Bodies somewhat siniiiar to asbestos bodies but much coarser and more iiregular have Ix-cn recovered from the lungs of coal miners wlm hud never worked in asiiestu' The morphological difference' are so great, however, that there is lit.lc or no risk of confusion. "T-s /i / f /<4/'cL CO o o CO a METHODS FOR " Two steps are m First, reduce the dt means of control tie to dust "action ante means of suitable i medical examinatie problem of rm-trom* tion of medical or pi balanced program. Individuals vary of dust owing to din weaknesses caused L tuberculosis, etc. selected for fitness chest X-ray picture inations thereafter resistance against a Two purposes ar development of tub< the victim can be rc: ous source of infect prevent the develo continued dust exp which lower the res in time to transfer : permanent damagprovides the- ouiy program, since in t: of lung damage th. program. An inudi control or the adopt - 396413 I