Document VKzzzJGE81vmgVo5bdBKzEm88

FILE NAME: Pennsylvania (PA) DATE: 1952 June DOC#: PA018 DOCUMENT DESCRIPTION: PA Dept of Health Report - Dusts DEPARTMENT OF HEALTH HAMKlMligta RUSSELL E. TEAGUE, M.O. SECRETARY DUSTS Burea u o r I n d u s t r i a l Hy g i e n e J o s e p h Sh b l e n , M.O. Di r e c t o r 3 /Hs. Mggft INDUSTRIAI. PROGRESS THROUGH INDUSTRIAL HEALTH DUSTS Revisad by Joseph S h ile n , M.L. D irector 2 , D e f i n i t i o n - d u s t may be d e fin e d as s o l i d p a r t i c l e s ra n g ing in s iz e from le s s than 1 m icron to about 160 m icrons ( l micron equals l/25000th of an in c h ). In in d u stry dusts a re produced by reducing s o lid m a te ria ls to sm all siz e s by such operations as crushing, g rin d in g , screening, d r i l l in g , and b la s tin g I I , P h y s ic a l p ro p e rtie s - when a s o lid is bro k en up in to f in e ly divided p a rtic le s , im portant changes occur Att, S u rfa c e a re a i s g r e a t l y in c r e a s e d , e . g . , I f 1 oubio centim eter of quartz w ith a to ta l surface area of 6 square centim eters is crushed in to p a rtic le s 1 cubic m icron in s i z e , t h e new t o t a l s u r f a c e a re a w i l l be 6 square meters B* Space o ccupied is in c re a s e d many tim es over volume o f o r ig in a l mass C, P h y s ic a l and chem ical a c t i v i t y o f m a te r ia ls in form of d u st is g r e a te r th a n when n o t d iv id e d 1. Increase in ra te s of a O x id a tio n b. Evaporation o. S olubility d. E lectrostatic activ ity e. A bsorption p ro p erties f . Brownian motion D. S e t t l i n g v e l o c i t i e s - r e s i s t a n c e to th e s e t t l i n g m otion of a dust p a rtic le through a ir v a rie s w ith the - 2- sine and shape of th s p a rtio le , w ith its v e lo c ity , and w ith th e f lu id ity of the a i r E. F lo c c u la tio n of d u sts - Brownian m otion of d u sts in a ir inoreases frequency of c o llisio n re su ltin g in form ation of flo c c u la te d masses 1 . E f f e c t o f air* m otion a. Increased a ir motion a c c e le ra te s form ation of floes 2, E ffeot of hum idity a* O rd in ary changes in h u m id ity have l i t t l e or no e f f e c t on f lo c c u la tio n b. S upersatu rated atmospheres have a n o ticeab le e ff e c t on flo o o u la tio n F . W etting 1 . C e rta in d u sts more e a s ily w etted th a n o th e rs 2 W ettin g can be o b ta in e d by a . In tim a te and v io le n t c o n ta c t between d u s t and liq u id b. A pplication of liq u id at dust source o. A ddition of agents w ith low su rfa c e te n s io n such as ammonia, a lc o h o l, e t c 0, to in c re a se w ettin g power of w ater G. E f f e o t o f e l e c t r o s t a t i c ch arg e 1. E l e c t r o s t a t i c c h arg es on d u s ts a re produced by F riotion b* Chem ical r e a c t i o n o r d i r e c t d i s s o c i a t i o n c. D irect actio n of ionizing agents I I I 9 C la s s ific a tio n of ducts according to com position A6 Organic duets 1 . Animal d u sts a. Feather b H a ir o. Leather d . Bone 2. Vegetable dusts a . Pollens b. G rain, flo u r, straw c . Hemp, c o tto n , j u t e , r a g , p ap er - 3- ty Le ir d. Spices, tobacco, ooffeo o. Wool, c o a l, etc B, Inorganic dusts 1. M etallic dusts a . Lead a rse n io , m ercury, manganese, z in c , etc. 2, Non-m etallio dusts a* S i l i c a ( q u a r t z , t r i d y m i t e , c r i s t o b a l i t e , e t c . ) , a s o e s to s , t a l c , gypsum, lim e, lim e stone, carborundum, emery, marble, g ra n ite , s la g , oement, g lass IV, C la s s ific a tio n of dusts according to physiologic re a c tio n A, A lle rg ic re a c tio n s 1, P o lle n s, most organic dusts B, Skin and o th er contact surfaces 1. Lime, chromic acid i 0 S ystem ic p o iso n in g s 1, Lead, manganese D, R eactions in th e lungs (based on experim ental p e rito n e a l in je o tio n s) 1 I n e r t r e a c tio n s a . Coal b. P re o ip ita to r ash c . Soapstone d. Talc e. Asbestos f . Feldspar g. Carborundum h . Heirat i t e i . S ericite 2, A bsorptive reactions a. C aloite b . Limestone c . Gypsum d. Cement 3, P ro liferativ e reactions a . Quartz b. T ripoli c. Siliceous chert - 4- V. F a c to rs in f lu e n c in g hazard o us e f f e c t of d u s ts A, Com position - p h y sical response is dependent upon com position l e Caloiuai carbonate - ab so rp tiv e re a c tio n 2 S i l i c a p r o l i f e r a t i v e r e a o tio n 3 Carbon - i n e r t r e a c tio n 4, Lead - system ic poisoning B* P a r t i c l e sis ~ p r a c t i c a l l y a l l i n d u s t r i a l d u s ts a r e o f th e same p a r t i c l e s iz e ra n g e 1 P a r t i c l e s g r e a t e r th a n 1C m icrons in d ia m e te r , seldom p re se n t in in d u s tr ia l atm ospheres 2 Physiological significance of p a rtic le s g reater th a n 10 m icrons n ot d e f i n i t e l y shown because a . R e la tiv e ly few are p resen t in th e b re a th in g zone b. Larger p a rtic le s are caught in the upper 1 r e s p ir a to r y tr a c t and removed by o i l i s r y a c tio n c . A lveoli are not la rg e enough to admit p a r t i c l e s g re a te r th an 10 microns in diam eter d . P a r t i c l e s g r e a te r th a n 10 m icrons in s iz e cannot be pnsgocyted 3. Recent work in d ic a te s th a t p a r tic le s g re a te r than 3 m icrons in diam eter have le ss p h y sio lo g ical im portance th an those under 3 microns 4e P a rtic le siz e of to x ic dusts is probably less im portant p h y sio lo g ically than th e ir w e tta b ility and s o lu b ility 5* A sb esto s d u s t p a r t i c l e s ra n g in g in s i z e up t o about 180 m icrons a re of p h y sio lo g ic a l im portance, probably as a re s u lt of m echanical i r r ita tio n of pulmonary tis s u e C. C o n c e n tra tio n - may be e x p re sse d in term s of w eig h t or number of p a r tic le s per u n it volume of a i r D. Length o f exp o su re E Dust r e t e n t i o n 1 . A pproxim ately 50 p e r c e n t o f in h a le d d u s ts a re re ta in e d ' g 3al y. je ly - 6- 2. Percentage re ta in e d increases w ith in creasin g r e s p i r a t o r y r a t e s up t o 20 r e s p i r a t i o n s p er m inute. Above th is r a te no f u r th e r change occurs S. Mouth b re a th e rs r e t a i n le s s d u st th a n nose b re a th e rs 4. F ib ro sis-p ro d u c in g d u sts are more r e a d ily re In th e lu n g s th a n smokes whioh c o n s is t o f much sm aller-sized p articles F. Individual su sc e p tib ility V I, Methods employed in dust d eterm in atio n s A, C om position - a i r - b o m e d u st may d i f f e r from th e m a te ria l from which i t is derived because of d if f e r e n tia l d is in te g ra tio n and s e le c tiv e s e ttlin g 1, C o lle c tio n of a ir-b o rn e samples a . S ettlem en t - r a f t e r samples b . By means o f (1 ) liq u id media (2) E le c tric al p re c ip itatio n (3) F iltra tio n ( 4) Impingement ( 5) Thermal p re o ip ita tio n 2, A nalysis a , Chemical b. Petrographic c. X-ray d iffra c tio n B. P a r tic le siz e 1, C o lle c tio n - s im ila r methods employed as noted above^under "com position" 2 M ethods o f m easurem ent a . L inear measurement (1) E ye-piece m icrometer in conju n ctio n w ith m icroscope (2) P ro je c tio n of miorosoopio f ie ld or p h o to m icro g raph on a s c re e n f o r com parison w ith scale (3) E lu tria tio n ( 4 ) C ount-w eight method - based on know- ledge of the density of th e m aterial - 6- aid th e number o f d u st p a r t i c l e s p e r ! gram C, C oncentration 1 C o lle c tio n a . Settlem ent - r a f t e r samples b , F iltra tio n - sugar tu b e, paper thim ble, li f ilte r paper e . Washing - r a in , m is t, spray d. Impingement d u st-la d e n a i r jjj sta tio n a ry surface produces a sudden'change in the d ire c tio n of flow w ith oonsequent lo ss of k in e tic energy of th e d ust and sep aratio n of th e d u st from th e a ir (1) Grab sample im pingers - (impingement on m icroscope s lid e ) (a) Konimeter - a ir stream induced by a sp rin g -actu ated valueless 1* p is to n pump a g a in s t a m icroscope slid e covered w ith a th in film of petroleum or glycerine je lly (b ) Owens' J e t d u st oounter n o zzle i v elo city higher than th a t of konim eter and no adhesive sub- i stan ce used on im pinging surface Dust p a r tic le s a re caused to ad here to cover s lip by condensation of m oisture about dust p a rtic le s which r e s u lts from a g reat drop in p ressu re w ith consequent lower ing of tem perature incurred by a ir passing through the nozzle (2) in te rv a l sam pling im pingers - (im pinge ment and tra p p in g in liq u id media) (a) Greenburg-Smith im pinger - nozzle and im pinging p la te are immersed in liq u id . Impingement tak es p lace in a i r since incoming a ir stream keeps p la te dry P hysical s ta te of dust p a rtic le s w ith th is - 7. method of impingement is a lte r e d and w e tta b ility is in c re a se d so t h a t th e y may be r e ta in e d in th e l i q u i d medium (3 ) Continuous sample im pingers (a) hazard re c o rd e r - ( impingement on a c e llu lo id s t r i p and photo e le c tric determ ination of dust in te n s ity ) e . E le c tric a l p re c ip ita tio n - based on e le c tr o s t a t i c a ttr a c tio n and io n ic bombardment of th e e l e c tr ic wind c re a te d by corona d isch arg e f , Thermal p r e c ip ita tio n based on th e p r in cip le of the presence of a w ell-defined d u s t - f r e e a r e a aro u n d a h o t r o d . When d u s t laden a ir is passed through a h o t-co ld tu b e, th e dust* is p r e c ip ita te d on th e cold su rfa c e 2 M easurem ent a . Weighing - w eight of d u st determ ined a f te r c o l l e c t i o n in p ap er t h im b le s , i n t e r v a l im pingers, e le c tric a l p re c ip ita to rs , therm al p re c ip ita to rs b . Counting - by means of a m icroscope and necessary c a lc u la tio n , th e t o t a l number of p a rtic le s of dust is determ ined fo r a u n it volume of a i r . This pro ced u re is q u ite s im ila r to th a t used in making blood counts c . Comparison method - d e te rm in a tio n of t o t a l dust; c o n c e n tra tio n p er u n it volume o f a i r based on a com parison of an unknown sam ple having a given appearance w ith th a t o f a known sta n d a rd d . Chemical a n a ly sis - s o lu tio n of d u sts in chem ical reag en ts and th e ir subsequent quanti t a t ive det erm inat ion June 1952 \ \ / HO* TO OBTAIN INDUSTRIAL HGXENE SERVICES The D i r e c t o r ^ o f f ic e and th e C en tral L aboratory of the Bureau are lo cated in H arrisburg. D is tr ic t o ffic e s are main tained in Altoona, E rie, H arrisburg, P hiladelphia, P ittsb u rg h , Scranton and W illiam eport. Requeete fo r s e rv ic e s of th e Bureau should be d ire c te d to the proper d is tr ic t office or to -- JOSEPH SHILEN, U. D ., D irecto r Bureau of In d u e tria l Hygiene Pennsylvania Department of Health 432 South O ffic e B uilding H a rrisb u rg , T e l. 5151 e x t. 2124 D is tric t O ffice Addressee Altoona 327 C e n tra l T ru st Bldg T el. - 3-1361 Philadelphia 155 S. 2nd S tr e e t T el. - Walnut 2-2399 Erie 152.1 G. D aniel Baldwin Bldg T el. - 2 -2 7B2 P ittsb u rg h 3400 Forbes S tr e e t T el. r Mayflower 1-1949 H arrisburg 1400 N. Cameron S tr e e t T e l. - 5151 e x t. 687 - 2894 Scranton 306 Scranton N a t'l Bank Bldg T el. - 4-3212 W illiamsport f 140 E. T hird S tr e e t T el. - 2-2759