Document x55aebX9px6yMYd8B0YQyEbr1

FILE NAME: Welding (WELD) DATE: 1950 DOC#: WELD034 DOCUMENT DESCRIPTION: lllinois/PHS Report Noting Fibrotic Hazard of Asbestos in Welding Rods [Pg. 98] 111(0/ P .H .S . Publication No. 31 H ealth of Ferrous Foundrym en U.S. PUBLIC HEALTH 79 ' SERVICE and I L L IN O I S DEPT, of PUBLIC HEALTH FEDERAL SECURITY AGENCY 1950 22900363033 22900363033 CONTRIBUTORS Environmental Studies L. E. R enes Senior Sanitary Engineer, U SP H S H. J. Paulus Scientist ( R) , U SPH S A. D. H osey Sanitary Engineer ( R) , U SP H S G. D. C layton Senior Sanitary Engineer, U SPH S H. H. Jones Junior Asst. San. Eng. ( R) , U SP H S D. H. Byers Senior Scientist, U SPH S C. D. Yaffe Senior Sanitary Engineer, U SP H S E. D. G odbold Chief Engineer Illinois Dept, of Public Health R. W. Courtney Engineer Illinois Dept, of Public Health Medical Studies H arry Heim ann Senior Surgeon, U SP H S H. T. Castberg* Senior Surgeon, U SPH S F. J. W alters Senior D ental Surgeon, U SP H S W. D. David Surgeon ( R) , USPHS A. W. M eyn Physician Illinois Dept, of Public Health Statistical Analyses H. P. B rin to n Senior Statistician, U SP H S M argaret E. Hook Statistical Assistant, U SPH S Deceased. For sale by the Superintendent of D ocum ents, U. S. G overnm ent P rin tin g Office, W a sh in g to n 15, D. C. -- P rice, 75 cen ts. PUBLIC HEALTH SERVICE PUBLICATION No. 31 HEALTH of FERROUS FOUNDRYMEN in Illin o is By The Division of Industrial Hygiene U. S. Public Health Service and The Division of Industrial Hygiene Illinois Department of Public Health PU 1950 ^ * *17 9 * FEDERAL SECURITY AGENCY Public Health Service Washington, D. C. WELLCOME INSTITUTE LIBRARY Coll. w e lN O m e c Call No. ~ W 3 CONTENTS FOREWORD ........................ ................................................................ Page ... 1 ACKNOW LEDGMENTS . . ........................................................................ 2 ABSTRACT-- SUMMARY . 3 IN T R O D U C T IO N .................................... 7 THE FOUNDRY INDUSTRY ...................................................................... 9 D escription of O p e r a ti o n s .......................................................................... 9 Jo b C la s s ific a tio n .................................................................................. 11 C orem aking D e p a r t m e n t ................ 12 M olding D e p a r tm e n t................................................................. 12 C asting C leaning D e p a r tm e n t................................................ 16 S hakeou t and Sand C o n d itio n in g ................ 16 M ain ten an ce and S upervisory .............................................. 19 M iscellaneous L a b o r e r s ............................................. 21 ENVIRONMENTAL S T U D IE S ................................................................... 23 Collection and A nalysis of S a m p l e s ....................................................... 23 F ield P rocedures .................................................................................. 23 L ab o rato ry P rocedures ............................................. 24 Particle-size F ra c tio n a tio n ....................................................... 25 F ree Silica .................................................................................... 26 I r o n .................................................................................................. 27 L ead ............................................... 27 R esu lts of E n v iro n m en tal S tu d ie s ............................................................ 27 A tm ospheric C o n tam in an ts-- D u s t ................................................ 27 C haracteristics ............................................................................. 27 F ree silica in air-borne d u s t .................................... 28 F re e silica in settled d u s t ................................................ 28 I r o n ......................................................................................... 29 L ead ...................................................................................... 30 R elatio n of particle size to w eight ................................ 30 Particle-size d istrib u tio n ................................................ 32 D u st C oncentrations ................................................................. 33 O ccupational W eighted E x p o s u r e s ...................................... 38 A tm ospheric C o n tam in an ts-- G ases ............................ 40 Irrita n t G a s e s ............................................................................... 40 C arbon M onoxide G a s ................... 40 D iscussion of A tm ospheric C o n ta m in a n ts .................................. 41 F acto rs Influencing F o u n d ry E n v iro n m en t ...................... 42 A ctivity and s p a c e ....................................................... 42 L ocation and scheduling of o p e r a t i o n s ................... 42 Size of castings and tonnage ...................................... 42 D egree of m e c h a n iz a tio n ................................................ 42 v Page V en tilatio n .................................... * ............. .................. 43 H o u sek eep in g and s u p e r v i s i o n ....................................... 43 R ecom m en d atio n s ..................................................................... 44 N oise .......................................................................................................... 44 M eth o d s of M e a s u r e m e n t....................................................... 45 Findings ......................................................................................... 45 C orem aking d ep a rtm en t ............................ 45 M olding d e p a rtm e n t ....................................................... 45 C leaning d e p a r t m e n t ....................................................... 47 R ecom m endations ...................................................................... 48 Illu m in atio n .............................................................................* ........... 48 F indings ......................................................................................... 48 R ecom m en d atio n s ...................................................................... 51 S a n ita tio n F a c i l i t i e s .......................................................................... 51 W ater S a p p l y .................................................................................. 51 D rinking W ater F a c i l i t i e s ....................................................... 51 W ashing F a c i l i t i e s ...................................................................... 52 T o ile t F a c i l i t i e s ............................................................................. 52 W aste D isposal ............................................................................. 53 H o u s e k e e p in g .................................................................................. 53 S um m ary .............................................................. 53 Su m m ary of E n v iro n m en ta l S t u d i e s ............................................................... 53 MEDSCAl S T U D IE S ....................... . ............... ........................... 55 Review of the L i t e r a t u r e ............................................................................. 55 M ethods of S t u d y ......................................................................................... 59 Personnel and Facilities ......................................................................... 59 T h e M edical E x a m in a tio n ................................................................. 50 R esults of M edical S t u d i e s ........................................................................... 55 C haracteristics of E x am in ed W o r k e r s ............................................ 55 B i r th p l a c e .......................................................... R ace ................................................................................................... 55 Age ..................................................................................................... 55 Sex .......................................................................................................... 56 M a rital S t a t u s ............................................................................. 56 P ersonal H a b i t s .......................................................................... 56 H ours of W o r k ................................................................................ 67 Y ears in F o u n d ry W o r k ............................................................. 57 O ccupation .................................................................................... 58 M edical F in d in g s ................................................................................. 59 P revious I l l n e s s ............................................................................. 69 P resen t S y m p t o m s ........................................................................... 69 W eight D e v ia tio n ...................................................... ................ E ye F indings .................................................................................. 73 vx Page Nose ....................................................... 74 H ern ia . .................................... 74 Skin ..................... 75 Jo in t and M uscle P a i n s ............................................................ 75 C ardiovascular-renal D is e a s e ................................................... 75 B lood S t u d i e s ............................................................................... 78 V ital C apacity .................................... 83 C hest R oentgenogram s ............................................. 84 P u lm o n ary tu b e r c u lo s is ................................................... 85 P u lm o n ary fibrosis . . . ..................................................... 96 C orrelation of P u lm o n ary F ibrosis W ith O ther D a ta . . . 101 P revious o c c u p a tio n .......................................................... 101 P rin cip al o c c u p a tio n .......................................................... 102 H isto ry of fam ilial tu b e r c u lo s is .................................... 104 O ther disease entities of respiratory and cardio vascular s y s te m s ............................................................ 105 C ertain sym ptom s, pulse rate, and w eight deviations 105 F re q u en cy of com m on c o l d ........................................... 105 Blood findings ................................................................... 106 V ital c a p a c i t y .................................................. 108 T obacco s m o k in g .............................................................. 109 D en tal F i n d i n g s ............................................... 109 D en tal C a r i e s ............................................................................... 110 S elected A bnorm alities of OralC a v i t y ................................. 113 A ttritio n ......................................................................................... 115 G arlic-like B reath ...................................... 119 S um m ary of M edical S t u d i e s ................... ............................................. . 120 R E FE R E N C E S..................................................... .......................................... 123 VII Digitized by the Internet Archive in 2021 with funding from Wellcome Library https://archive.org/details/b3217 495 FOREWORD In the past 30 years, great strides have been m ade in the control oi silicosis, b u t despite these advances on a broad base, there continue individual instances in which the disease still endangers the health and life of workers. M ounting evidence has pointed to the foundry industry as a remaining source of exposure to silica dust, but at the same tim e it has been felt b y som e that the cases still com ing to light in this industry are the result of preexisting rather than present im proved conditions. In order to determ ine the actual facts, an inves tigation was conducted b y the Public H ealth Service in cooperation w ith the State D epartm ent of Public H ealth in Illinois. I t is hoped that the correlated findings of the medical-engineering team s presented in this report m a y help to clarify this question and aid further in the prevention and control of a serious hazard. J. G. Townsend, M edical D irector CHIEF, DIVISION OF INDUSTRIAL HYGIENE U. S. PUBLIC HEALTH SERVICE K. M Morse CHIEF, DIVISION OF INDUSTRIAL HYGIENE ILLINOIS DEPARTMENT OF PUBLIC HYGIENE 1 ACKNOWLEDGMENTS G rateful acknow ledgm ent is m ade to th e m anagem ent and em ployees of th e 18 ferrous foundries covered in this investigation, whose cooperation m ade this study possible. A ppreciation is also expressed to the trade associations and labor organizations th at contributed invaluable assistance. W e should like to th a n k p a rtic u la rly M r. C. C. M urphy, of th e Chicago F e d e ra tio n of L abor, A FL ; th e Illinois State Industrial Union Council, CIO; the Chicago Industrial Union Council, CIO; D istrict 31 of the U nited Steelw orkers of America, CIO; Local 1545 of the U nited Steelworkers of America, CIO; Region IV of the U nited Automobile, Aircraft, Agricultural Im plem ent W orkers of America, UAW -CIO; the N ational Foundry Council, CIO; the Chicago F o u n d ry m e n 's Association, an d th e Chicago an d V icinity M olders' Conference Board, International M olders' and Foundry W orkers' Union of N orth America, AFL. T he Rockford City H ealth D epartm ent and the Division of L abora tories, Illinois State D epartm ent of Public H ealth, contributed greatly to the progress of the study by m aking their laboratory facilities avail able for dust-counting. A cknow ledgm ent is also m ade to the Industrial Commission of Illinois, which m ade available to the investigators data on com pensa tion claims of ferrous foundry workers for chronic pulm onary disease. Senior Surgeon Ira Lewis, Chief, X -R ay Study Section, Division of Tuberculosis, Public H ealth Service, assisted m aterially in interpreting those roentgenogram s suspected of showing pulm onary tuberculosis. Personnel of the Division of Industrial Hygiene, Public H ealth Service, who also aided in the study include Joseph E. Flanagan, J. W alter Hough, D avid Zinke, Joseph Fridl, R obert B. Crothers, F re d erick N evins, Jo h n K. Brown, D u n can A. H oladay, D. E. R ushing, B. E. Saltzm an, N. A. T alv itie, J. A. S utton, E. P. F loyd, V ernon B. Perone, and Ljubo Lulich, while, from the Division of Industrial Hygiene, Illinois D epartm ent of Public H ealth the efforts of Alfred N. Setterlind, George W inkler, M arvin Scheunemann, and Lawrence S. H ill are gratefu lly recognized. 2 A B S T R A C T -- SUMM ARY This report presents the clinical and environm ental findings of a cooperative investigation into the exposures of ferrous foundry workers to silicosis and other hazards. Extending over a 1-year period, the study was conducted in Illinois by the P ublic H ealth Service in cooperation with the State D epartm ent of Public H ealth. Prior to this study, a prelim inary survey had been m ade of iron and steel foundries in the State. Of a total of 185 foundries surveyed, 18, w hich w ere considered as rep rese n tativ e of th e in d u stry in Illinois, were selected for this study. E n v iro n m en tal investigations w ere m ade in 18 ferrous foundries, in which approxim ately 1,100 sam ples of air-borne dust were collected and studied. It was found that 90 percent or more of the air-borne dust in all foundry environm ents w ere three m icrons or less in size. T he am ount of free silica in the air-borne dust varied w ith the opera tion an d ran g ed from 13 p ercen t a t corem aking to 29 p erce n t in pouring, shakeout and sand conditioning. On the other hand, the free silica content in the settled dust was found to average 30 percent throughout the foundries. T he air-borne dust less than 5 m icrons in size was found to have a lower percentage of free silica than the larger size fraction. T he percentage of iron in the air-borne dust was found to range from 3 to 9 percent for all operations except casting cleaning, for which the proportion varied from 30 to 38 percent. O perational dust levels at various foundry activities in general were found to be m uch lower than those reported in earlier investigations. M ean dust levels at molding, pouring and corem aking operations were found to be under 3 million particles per cubic foot of air. Sand slinger m olding show ed a m ean d u st level of ab o u t 19 m illion p articles per cubic foot. M echanical shakeout operations showed m ean dust levels ranging from 10 to 75 m ppcf; w hereas m anual shakeout and sand conditioning produced m ean dust levels under 7 mppcf. Cleaning room operations showed m ean dust levels under 7 m ppcf except at portable grinding and chipping, which had a m ean dust level of about 15 m ppcf. O th er m iscellaneous o p eratio n s show ed d u st levels u n d er 4 mppcf with the exception of chipping-out cupolas and sand unload ing. T h e high dust exposures a t the last two activities w ere in ter m ittent and of relatively short duration. 3 Concentrations of aldehydes were of a low order of m agnitude. Car bon monoxide concentrations were relatively low in m ost instances, but high levels occurred for short periods at pouring operations during the w inter months. In general, the foundries studied were clean; housekeeping was ade quate; and dust suppression m easures were employed. M any of the foundry buildings were well constructed according to m odern archi tectural designs which perm itted adequate natural ventilation and natural illumination. Although the m ajority of the foundries were not com pletely mechanized, m odern production techniques were usually em ployed. M any of the foundries did not utilize the latest m ethods of artificial illumination. The foundries studied gave little consideration to the reduction of noise. In general, sanitation facilities provided for em ployees were ade quate and m aintained in a satisfactory condition. Some im provem ents were needed in a few plants. M edical exam inations w ere m ade of 1,937 m ales em ployed in 16 ferrous foundries. From the standpoint of socio-economic status and exposures to hazardous m aterials in the occupation, these m en are believed to comprise an adequate cross-section of ferrous foundry workers in the area studied. As m ight be expected, the m ost significant clinical findings dealt w ith those of the respiratory system. Pulm onary fibrosis of occupa tio n al origin w as found in 9.2 p ercen t of the m en; in 7.7 p ercen t it w as ground glass tw o stage a n d in 1.5 percent, nodular. T h e fibrosis was of about equal frequency in steel and gray iron workers. Among the gray iron foundrymen, the m olders showed the highest incidence of nodular fibrosis; whereas, am ong the steel workers, those perform ing cleaning and finishing operations had the highest rate. It generally req u ired a t least 14 y ears of exposure to p roduce n o d u lar silicosis in foundry work. T he blood studies indicated th at pulm onary fibrosis was associated with increased erythrocyte sedim entation rate and elevated total leucocyte counts. Significantly elevated blood pressure levels were found to be related to increasing degrees of pulm onary fibrosis. R einfection ty p e of tuberculosis w as found in 0.7 percent of w hite w orkers an d in 1.7 p ercen t of th e N egroes, orders of m ag n itu d e sim ilar to those of other studies of adults of both sexes m ade in the general population in the same area. T he lim ited exam inations m ade of the eyes revealed no abnor m alities which could be ascribed to the occupation. Skin disease, prob ab ly of occupational origin, w as found in 1.7 p ercen t of th e m en. 4 T he oral structures were modified in the occupation only to the extent th at there was attrition of the tooth surfaces. This was attrib uted to the dusty nature of the occupation. T he correlation of the clinical and environm ental findings reveals th a t there is reason to believe th a t dust conditions in the foundries studied have im proved in th e p ast 10 to 20 years. T hus, it is likely th a t in m any instances the pulm onary fibrosis observed w as due in g reat p a rt to higher d u st co n cen tratio n s w hich p ro b ab ly existed 10, 15 or m ore y ears previously in th e foundries. T h e conditions noted, however, generally leave room for im provem ent in the control of silica and other hazards. Based on our observations during the study, the following recom m endations are presented: Exhaust system s and dust collection equipm ent should be given proper m aintenance. W hen buildings are to be rem odeled or new ones built, consideration should be given to the location of various opera tions in order to minimize the num ber of workers affected by the high dust producing operations. V ery dusty operations should be scheduled when few workers are present. Local exhaust ventilation should be em ployed w hen m echanical shakeout equipm ent is used. E xhaust ventilation should be em ployed w ith portable grinding. A dequate ven tilation should be provided to prevent excessive concentrations of carbon monoxide during pouring operations and around furnace charg ing. P articu larly noisy m achines should be isolated w henever possible, or appropriate acoustical treatm ent should be em ployed where they are located. M odern lighting techniques should be em ployed to improve artificial illumination. 5  V' > >r f r ,<q -rA0 Zr\ ir r-' ' '>ft; '7 * ; . V r <--<!" C ' '' rr t?.. -1 INTRODUCTION Studies of the health of ferrous foundry workers have been made during the past two decades in m any parts of the world. In m ost reports of such studies the dust hazard reasonably received m ajor consideration. However, in spite of these m any investigations, with resultant recom mendations, the dust hazard still appears to be a real one. T his was especially brought to our attention by health officials of three M idw estern States. T hese officials pointed out th a t in their respective jurisdictions claim s for silicosis am ong w orkers in the ferrous foundry industry were continuing in spite of apparent im provem ent of environm ental con ditions. They, therefore, requested th at the Public H ealth Service engage in an investigation of the m atter. Following prelim inary con ferences w ith these officials, and others concerned, it was agreed th at the Public H ealth Service, w ith the cooperation of the States, would m ake a study of the health status of the workers in the industry, and th at special em phasis would be placed on certain of the diseases which m ight be related to the occupation. It was further agreed th at the study would be m ade in the State of Illinois together w ith the D epart m ent of Public H ealth of that State. E ighteen foundries w ere studied environm entally; of these, 16 were studied medically. T he selection of the plants for study was based on an effort to obtain examples of different types of ferrous foundries; th a t is, sm all an d large, m echanized an d nonm echanized, g ray iron and steel, and patently dirty and clean. B oth m edical and environm ental data were collected during a period of ap p ro x im ately 12 m onths, beginning in A pril 1948. 7 THE FOUNDRY INDUSTRY F or the year 1947, the latest year for which pertinent inform ation was available, there w ere 1,936 independent ferrous foundries in the U nited States, em ploying a total of 239,272 w orkers (1 ). T able 1 shows their distribution by State. These foundries, together w ith all captive1 ferrous foundries, em ployed approxim ately 341,000 produc tion workers. Description of Operations T he principal steps in the m anufacture of iron or steel castings are as follows: P reparation of m olding m aterials; m aking of m olds and cores; m aking and pouring of hot metal; rem oval of castings from the m olds and rem oval of cores; and cleaning of castings. T he preparation of molding m aterials consists essentially of condi tioning the core and m olding sands. Core sand is usually prepared in large batches in a rotary m ixer by using fresh sand, free from clay, w ith certain ingredients w hich m ay include flour, a cereal binder, a pitch binder, and linseed oil. M olding sands consist of facing sand, w hich is used on the surface of the mold, an d heap sand, w hich fills up the rest of the mold. Facing sand is prepared either by the fine screening of heap sand or by mixing definite proportions of old sand and fresh sand w ith various m aterials, such as sea coal, bentonite, and corn flour. H eap sand is recovered m olding sand to w hich w ater, a certain am ount of fresh sand, and sometimes a clay bond, are added. T he w et sand ingredients m ay be mixed by hand, by moving harrows, or by large m echanical mixers. Cores are m ade by introducing sand into wooden or m etal molds. D epending on the size and other requirem ents, cores m ay be m ade by bench, floor, or m achine molding. Cores are baked usually in a gasfired oven equipped w ith m echanical ventilation. A fter cooling, the core is scraped to rem ove loose, surface sand and is then ready for use in the preparation of the molds. M olding consists of em bedding a wood or m etal pattern in sand. W hen the pattern is withdraw n, it leaves a hollow space or m old in the shape of the casting desired. M olds for sm all castings m ay be m ade by bench or m achine molding, while molds for large castings are usually m ade on the floor or in a pit. In the preparation of th e molds, 1 A captive foundry m akes castings for use by itself or its parent com pany in the fabrication of other finished or sem ifinished products, and is not engaged in the production of castings for sale. 9 T a b le 1.-- N u m b e r o f in d e p en d en t ferrous fo u n d ry esta b lish m en ts and num ber of their production workers in the U nited States according to state, 1947 State Number of pro Number of duction workers establishments (average for the year) T otal__ Pennsylvania __ Ohio_________ M ich ig an _____ ILLIN O IS___ California____ New York____ I n d i a n a ______ Wisconsin____ Massachusetts. New Jersey___ A la b a m a _____ M in n e so ta ____ Texas________ Missouri_____ North Carolina Virginia______ Iowa _________ Tennessee____ C o n n e c tic u t __ W ash in g to n __ Oregon_______ Georgia______ Colorado_____ K ansas_______ All other_____ 1,936 222 201 149 143 131 111 105 84 78 69 60 48 43 41 35 33 32 31 30 27 25 23 21 20 174 239,272* 30,930 33,115 4 2 ,802 23,021 8,002 11,444 14,820 10,962 4,024 7,835 12,884 2,052 2,485 5,450 1 , 104 2,657 1,965 4,120 3,919 1,079 1,171 785 1,068 984 6,167 ^Includes all production workers for the U nited States. T he sum of the State num bers below , however, is only 2 3 4 ,8 4 5 . T h e difference of 4 ,4 2 7 represents the sum of unpublished State data distributed am ong the follow ing States: Alabam a, Arizona, Arkansas, California, Connecticut, D elaw are, Florida, Idaho, Iowa, Louisiana, M assachusetts, M innesota, M issouri, M ontana, N ebraska, N ew Ham pshire, N ew Jersey, N ew M exico, N ew York, N orth Carolina, N orth D akota, Oklahoma, R hode Island, South D akota, Texas, U tah, and W est Virginia. Source: R eferen ce 1. the m olding sand m ay be handled either m anually-- by shoveling; or m echanically-- by dumping from an overhead conveyor or by a sand slinger m achine which throw s the sand into the mold. T he small finished molds are usually carried to the pouring area by the molder, while large m olds are poured in place. T h e m olten m etal th a t is poured into the m olds to form th e casting is prepared in a furnace. T he ty p e of furnace used depends on the type of m etal desired. F o r gray iron, a cupola is used; for m alleable iron, 10 an air furnace; and for steel, an open-hearth or electric furnace. In the operation of the cupola, weighed am ounts of pig iron, scrap iron, limestone, and coke are charged in alternate layers. T he com bustion of the coke, aided by a forced draft, m elts the iron, which settles to the bottom . In the operation of the furnaces used for the preparation of m alleable iron and steel, the raw m aterials are essentially the same as in the cupola; however, since the fuel is not m ixed w ith th e charge, th e am ount of im purities in th e finished product is decreased. In addi tion, special care is tak en in th e am ounts of raw m aterials added, and the com position of the m olten m etal is m ore carefully controlled. W hen th e h eat is ready, th e furnaces are tapped, and the m olten m etal is transported by ladles to the pouring area. Pouring into th e m olds is accom plished either m echanically or m anually, depending on the size of the castings and the degree of m echanization of the plant. T h e flasks, w hich enclose the mold, are rem oved im m ediately after the m olds have been poured, and five m inutes to several hours later, depending upon th eir size, th e hot castings are rem oved. M anual m ethods are norm ally used in dragging small castings from the sand, and in some plants the larger castings are also rem oved m anually. M echanical shakeout methods, consisting of vibrators, chain hoists, cranes, vibrator platform s and pneum atic hammers, m ay be used for large castings. Large cores, gaggers, rods, and the like are rem oved from the large castings by either m anual or m echanical methods. Risers and sprues on small iron castings are rem oved by a ham m er blow. In the case of large iron and all-steel castings this operation is accomplished by an oxy-acetylene torch. T he castings are transported to the cleaning departm ent where sand and excess m etal are rem oved. M ost of th e sand is rem oved from th e casting by two m ethods: tum bling and blast cleaning. Tum bling involves the repeated striking of castings against each other and against hardened iron stars in a rotating barrel. A brasive blasting is accomplished by directing a stream of abrasive particles, such as sand, synthetic abrasive or chilled grit, or shot, against the casting a t high velocity. T he rem ainder of the sand and the excess m etal m ay be rem oved by various operations, including stationary grinding, portable grinding, swing grinding, pneum atic chipping, and burning. JOB CLASSIFICATION Since the differences in the size and type of foundries (gray iron, m alleable iron, or steel, and production or jobbing), in the degree of m echanization (m anual or mechanical or a combination of both), and in the size of castings m ade for a diversity of operations, a job classi fication of the w orkers m ust be generalized. All of the w orkers included 11 in this study of the foundry industry in Illinois w ere divided into six broad groups according to the location and nature of the work in volved. These groups are: corem aking departm ent, molding depart ment, casting cleaning departm ent, shakeout and sand conditioning, m aintenance and supervisory, and m iscellaneous laborers. In the fol lowing pages the operations perform ed and the m achines and m aterials used by each group are discussed by occupation. Coremaking D epartm ent T he corem akers constitute the greatest num ber of individuals in this group. T heir work consists of fashioning cores, using a hollow form (core box) and forcing into it a cohesive m ixture of core sand. T he work m ay be accom plished by m anual (bench or floor corem aking) or by m echanical m ethods (m achine corem aking). Small cores are m ade by bench and m achine coremaking, and large cores are usually m ade on the floor. In m ost foundries the corem akers spend the entire working day at this operation, although in some of the sm aller found ries from one to two hours m ay be spent in pouring or shakeout operations. T he core oven tenders load, unload, and fire the oven in which the cores are baked. T he various operations of this occupation usually consume the working day. T he core room laborers perform a num ber of different tasks that include scraping cores, mixing core sand, mixing paste, hauling fuel for th e oven, sweeping floors, transporting core sand and core boxes, and cleaning core boxes. Additional core room personnel include core pasters and core assemblers. T heir w ork consists of scraping core sections, applying paste to the core surfaces to be joined, and fitting the sections together accurately. M olding D epartm ent In m ost foundries m olders constitute the largest num ber of workers in any single occupation. T h e prim ary function of m olders is to pre pare th e sand m olds in which m etal is cast. Basically, this involves packing sand around a pattern of the desired object and then w ith draw ing the pattern, leaving in the sand a hollow space in the shape of a casting to be made. T he bench m older applies facing sand through a hand screen, fills up th e flask w ith heap sand, and tam ps the sand in place w ith a hand or pneum atic ram m er. Loose sand is blown from two halves of the mold; the cores are placed, and a parting com pound is applied. T h e m old is assem bled and is placed on th e floor ready for pouring. Floor and pit molders perform essentially the same rou tine except th at the molds are m uch larger and cranes or hoists are 12 F ig u re 1.-- T am p in g sand in to a large floor m old w ith a pneum atic tool. N ote the large window space which aids in providing natural ventilation and illumination. used to lift the flasks and patterns. M achine m olders operate m achines th at pack the sand by either squeezing, bum ping or jolting. Some large foundries, especially if floor or p it m olds are m ade, use sand-slinger m achines which are controlled by a sand-slinger operator. Sand placed in a hopper of the sand-slinger is autom atically sifted and carried to the end of an arm, w here it is throw n into the flask w ith enough force to pack it, thus saving han d labor in packing the mold. T he sand-slinger operator works w ith m olders who set up and finish the mold. In m any foundries the m older also perform s the task of pouring the m olds he has m ade. T his task is done usually a t th e end of th e w ork day and requires from one to two hours. A num ber of laborers are usually assigned to the m olding depart m ent to perform unskilled tasks, such as sifting and shoveling sand, carrying equipm ent and m aterials to the working area, pouring molds, shifting weights, and rem oving flasks. 13 F igure 2.-- M achine m olding of sm all castings. M o ld er's h elp er a t th e left is shoveling sand into a screening device to provide facing sand for the mold. P ile of heap sand is in th e right foreground. F igure 3.-- L ine of m achine m olders. M olding sand is provided b y an overhead conveyor system. Finished molds are taken to a central pouring area by the conveyor directly behind the molders. 14 F ig u re 5.-- P ou rin g sm all m olds a t a ce n tral pouring station. N o te furnace operator tapping air furnace in background. 15 Casting Cleaning D epartm ent Tum bler operators are laborers who load and unload the tum blers and m ay transport the castings to and from the area. These workers m ay also have other tasks in the cleaning departm ent or during the pouring operation. T he wheelabrader operator runs a machine which cleans castings by both tum bling and blast cleaning methods. This laborer also loads and unloads the machine, and m ay perform other tasks in the cleaning departm ent. Sandblasters and tableblasters use the m ethod of blast cleaning to rem ove the sand from the castings. Sandblasters m ay collect and trans port the castings to the sandblast room, where they clean the castings. T he tableblaster, on the other hand, operates a m achine in which cast ings are carried through a cham ber w here one or m ore nozzles direct stream s of abrasive-laden air against them. The worker collects and transports the castings, places them on the circular rotating table of the machine, and removes the castings from the table when they are cleaned. T he grinders and chippers remove the excess m etal from the cast ings and the sm all am ount of sand rem aining after precleaning opera tions. G rinders m ay be classified according to the m ounting of their machines. Thus, there are stand or stationary grinders, swing-frame grinders, and portable grinders. Chippers em ploy a pneum atic tool to rem ove m etal fins and rough spots from the surface of the castings. In the larger foundries the grinders and chippers usually work at the same job for the entire day. In sm aller foundries, or in foundries where large castings are m ade, th e sam e w orker m ay perform stand, swing, and portable grinding, and pneum atic chipping during the same day. Burners rem ove gates, risers, and projections from iron and steel castings with an oxy-acetylene torch. Cleaning departm ent laborers perform a num ber of tasks which include transporting castings, knocking off risers, rem oving cores, and sweeping floors. Shakeout and Sand Conditioning T he shakeout operations in m ost foundries are perform ed by a group of laborers who also m ay condition or prepare the sand for the next d ay 's work. S h ak eo u t operatio n s v ary w ith th e size an d degree of m echanization of the foundry and size of the castings. B oth m anual and mechanical m ethods are used to free the casting from the mold and to transport it to the cleaning departm ent. W here m anual shake out m ethods are used, the tasks m ay include rem oving flasks, knocking off risers, dragging out castings, loading castings and transporting them 16 F igure 6.-- R em oving rough spots from casting b y p o rtab le grinding. F ig u re 7.-- S tan d (s ta tio n a ry ) grinding sm all castings. N o te fluor escent lights and ducts of exhaust ventilation system. 17 F igure 8.-- R em oving excess m e tal from casting b y pneum atic chipping. F igure 9.-- Castings em erging from a m echanical exhaust v en tilated shakeout system. Laborer removes and places large castings in wheel barrow; conveyor system carries small castings to sorting room. 18 F ig u re 10.-- S h akeo u t of casting from floor m old using a chain hoist. to the cleaning departm ent, stacking bottom boards, picking up risers, wetting sand, and cutting the sand by hand. M echanical shakeout m ethods m ay include the use of cranes or hoists to lift and transport the m olds and the castings, vibrator platform s to shake the casting out of the mold, pneum atic ham m ers to knock the sand loose, and vibrator hoists to shake small castings from the molds. Sand m ixers prepare the core, facing, and heap sands for use by the corem akers and molders. This work m ay be done by hand, using a shovel or by the operation of mullers or cutters. T he sand mixer m ay be required to load, unload, and operate the muller, and transport the sand to th e place w here it is to be used. Some foundries have com pletely m echanized sand-treatm ent system s which the operator can control from one location. T he am ount of tim e required for the sand treatm ent operations varies from plant to plant. In small foundries the sand m ixer usually has num erous other tasks, while in large foundries the entire day m ay be spent at this operation. M aintenance and Supervisory M aintenance workers are required to repair, service, and m aintain the m achinery and equipm ent in the foundry. D epending on the size of the foundry and degree of mechanization, the following m aintenance 19 F igu re 11.-- S h ak eo u t of castings using a p n eu m atic vibrator hoist. Sand falls through grillwork in floor onto conveyor belt which carries it to the sand condi tioning unit. em ployees m ay be necessary: carpenters, electricians, mechanics, and millwrights. These workers m ay perform their jobs in all sections of the foundry and usually are not required to do other tasks. Supervisory personnel includes superintendents, assistant superin tendents, foundry foremen, and departm ent foremen. These men plan, coordinate, and are responsible for work under their direction. Shipping and receiving clerks perform various tasks connected with the incoming m aterials and equipm ent and the outgoing products. Office w orkers perform bookkeeping and tim ekeeping, m aintain cor respondence, and do other tasks necessary in the conduct of foundry business. T hese workers spend little tim e in the foundry workrooms. 20 M iscellaneous Laborers This group includes all the rem aining foundry workers who do not qualify for the other five groups. Included in this group are occupa tions which are sufficiently im portant from the dust-hazard standpoint to be in a group by themselves, but the sm all num ber of w orkers in these occupations m ake separate consideration of the occupation unw arranted. Furnace workers include melters, cupola chargers, m elter helpers, ladle liners, and brickmasons. T he m elters supervise the work involved in operating a furnace (cupola, air, electric, open-hearth) in which th e m olten m etal is prepared. T he cupola chargers weigh and transport the raw m aterials to the charging platform, where they shovel or dum p the constituents of the charge into the cupola. T hey m ay also assist in other tasks around the cupola. T he m elter helpers perform num erous tasks in the operation of the furnace. These include chipping or cleaning out the furnace, repairing furnace, cleaning out slag, preparing slag bed, assisting in tapping furnace, operating bull ladles, and helping to pour. Ladle liners chip out and clean ladles, and prepare and apply the m aterials necessary to patch or replace th e linings of ladles. Brickm asons construct and repair the brickwork of furnaces, stacks, and ovens by spreading m ortar and placing bricks according to dia grams or blueprints. T he crane operators operate a crane, which runs on overhead rails in the foundry building or in the m aterial yard, to lift and transport heavy objects, such as large flasks, molds, patterns, m achines, raw m aterials, castings, and ladles of m olten m etal. In m ost foundries these workers spend the entire day at this occupation. T he hoist operators, using a chain or com pressed air hoist, perform the sam e tasks as the crane operators b u t on lighter loads. These w orkers usually perform other tasks in the departm ent in which they work. Pattern m akers construct patterns of wood or m etal which have the shape and size of the desired casting Annealers operate an annealing oven in which castings are heattreated to form m alleable iron. Yard m en perform a num ber of tasks, including unloading sand from box cars, storing and moving m aterials, helping load and unload trucks, and cleaning up. 21 Truck drivers load, unload, operate, and m aintain m otor trucks to transport plant products, incoming m aterials, and supplies. Guards perform the police work in and around the foundry and protect the equipm ent and m aterial from theft. Janitors and sweepers m aintain the entire foundry including the supply room, washrooms, and office rooms, in a clean condition. From these job descriptions and observations m ade of various operations in the foundry industry during the course of the study, it appears that the m ajor health hazards to workers are exposure to silica dust, iron dust, carbon monoxide, aldehydes and to such physi cal agents as heat, rapid changes in temperature, noise, and bad illum ination. 22 ENVIRONMENTAL STUDIES T he engineering phase of the ferrous foundry investigation included an evaluation of various environm ental factors, such as dusts, gases and other contam inants, noise, illum ination, and plant sanitation. T he study was extended over a 1-year period to include all w eather condi tions. T h is investigation was carried out in 18 Illinois foundries located w ithin a hundred-m ile radius of Chicago. T he num ber of em ployees per foundry ranged from 26 to 400. T he size of the castings produced varied from less than one pound to approxim ately 40 tons. T he foundries selected produced gray iron, m alleable iron, and steel castings. T he m ajority of the plants worked only during the day except for shakeout operations, which were com m only done at night. A few of the plants surveyed, however, w orked two or three shifts, w ith shake out being done on all shifts. Collection and Analysis of Samples FIELD PROCEDURES T he num ber of samples collected at each operation was determ ined by the nature and dustiness of the operation. In the first portion of the survey, three or more dust samples were collected at each operation in each foundry. As the survey progressed, it was decided to collect fewer samples, provided they gave consistent results. For each opera tion, however, sam ples were collected on different days as well as at different hours of the day. A pproxim ately 1,100 sam ples of air-borne dust were collected and counted. In addition, num erous samples were collected for determ ination of iron, free silica, and particle size. Con centrations of carbon monoxide and aldehydes were also determ ined. D epending upon the inform ation desired, three m ethods were used for the collection of air-borne dusts. T he standard technique em ploy ing the standard im pinger was used in collecting samples for dust counting and particle-size determ inations (2 ). T he sampling medium was 100 m illiliters of double distilled water. W hen necessary, impinger tubes w ere rebored to m aintain a flow of 1 cubic foot of air per m inute (plus or minus three percent) at a pressure drop of three inches of m ercury. Sam ples were taken in the operators' breathing zones as well as in the general room air for periods of from 5 to 30 minutes. A vacuum cleaner, equipped w ith a double thickness paper filter, was used for collection of large am ounts of air-borne dust for chemical 23 analysis. These samples were elutriated, and the fractions thus obtained were each analyzed for free silica. T he intake to the cleaner was suspended approxim ately 7 or 8 feet above floor level. T he cleaner was operated at a sampling rate of about 30 cubic feet of air per m inute and run from 8 to 40 hours, depending upon the dustiness. T he modified electrostatic precipitator (3 ) was used to collect dust and fum e at all operations for determ ination of iron. T he precipitator was operated at a sampling rate of 3 cubic feet of air per m inute for 5 to 30 minutes. Samples of settled dust were collected from overhead beam s and rafters. These sam ples were analyzed for free silica and iron. T he N ational Bureau of Standards carbon monoxide indicator tubes (4 ) were used for determ ination of carbon monoxide. T ests were made in the operators' breathing zones during pouring operations. T ests were also m ade throughout the day in the vicinity of the cupola and of the general room air. Sam ples of mixed aldehydes were collected in the vicinity of the pouring operation by m eans of a m idget bubbler using sodium bisulfite as a collecting medium. T he samples were taken at the rate of 2 liters per m inute with an autom atically-controlled suction device ( 5 ) . Analysis (6 ) of the mixed aldehydes was perform ed by the Industrial Hygiene Division, Illinois D epartm ent of Public H ealth, which designed and furnished the apparatus used. A num ber of sam ples of molding, facing, and core sands, and of parting com pounds were collected and analyzed for free silica. T he standard light-field counting technique, using D unn cells and a magnification of 100X, was em ployed (2 ). E ach cell had been care fully ground to provide a cell depth of one millim eter, plus or m inus three percent. D ouble distilled w ater was used to wash down the sides of the flask and the center tube and to dilute the sam ple to 250 ml. Samples containing visibly high dust concentrations were further diluted as required. A blank count determ ination was m ade for every five sam ples counted. Cleanliness of all sam pling and collecting equip m ent was m aintained so th a t blank counts did not exceed 8 particles per microscopic field. All dust counts were m ade in the field w ithin 24 hours after collection. F our to six im pinger sam ples taken at the same operation at a given foundry were com bined for the preparation of slides for particle-size determ ination. Particle-size distribution was determ ined with the filar m icrom eter using an oil im m ersion objective (7 ). - LABORATORY PROCEDURES T he sam ples which were returned to the laboratory for analysis fell into four general groups, according to the type of sam ple and the m ethod of collection. T he four groups follow: 24 Bulk sam ples of parent materials, including various types of sands and parting compounds, were collected as used in the plants. Some were already powdered, and others were relatively coarse. All were ground to pass through a 100-mesh sieve and thoroughly mixed before the portions for analysis were taken. Sam ples of rafter dusts were thoroughly mixed, and portions were taken for analysis for the determ ination of iron. T he determ inations for free silica were m ade only on th at portion of the sam ple which passed through a 200-m esh sieve. Electrostatic precipitation was used for the collection of a num ber of sam ples of air-borne fume and dust. Although a few of these sam ples were analyzed for lead and some for free silica, m ost of them were analyzed only for iron. In all instances the sample was rem oved from the electrode tube by washing with 30 percent alcohol-water solution, accom panied by vigorous scrubbing w ith a rubber policeman. Gross samples of air-borne particulate m atter were collected on filter paper, as previously described. T he samples were rem oved from the filter paper by repeated washings in alcohol. T h e paper was placed in a beaker, covered w ith alcohol, and agitated to loosen the particles. T he paper was then rem oved to another beaker and agitated with another portion of clean alcohol. This procedure was repeated until the paper and the last several portions of alcohol appeared to be clean and free of dust. All alcohol portions were com bined and centrifuged to concentrate the particulate m aterial of the sample. T he samples were then separated into two particle-size fractions, as described below, and each fraction exam ined for free silica by the X -ray diffrac tion technique. Particle-size Fractionation T he separation of dust samples into particle-size fractions was accomplished by a sedim entation procedure sim ilar to that used by H olden and H yatt (5 ). Two marks exactly 33 millimeters apart were m ade upon the side of a 400 m illiliter beaker. T he lower m ark was approxim ately 20 millim eters above the bottom of the beaker. T he sam ple was placed in the beaker and redistilled alcohol added to the upper mark. T he m ixture was agitated to put the dust into suspension, then allowed to settle for 40 minutes. T he suspension rem aining betw een the two m arks was slowly siphoned into a centri fuge flask by m eans of a tube connected to a vacuum line. Care was taken th at the suspension was agitated as little as possible by the siphoning operation. Clean alcohol was added to bring the level to the upper m ark on the beaker, and the procedure of agitating, settling, and siphoning was repeated. This cycle was continued until the upper layer appeared clear. 25 A fter siphoning, the upper layer containing the fine particles was centrifuged to bring down all particles, and the clean supernatant liquid was decanted. T he same centrifuge flask can be used throughout the sedim entation of a sample regardless of the num ber of cycles of operation required to give a clear upper layer. A fter a final centrifuging and decanting, the two fractions were dried by evaporating off the alcohol and then weighed. T h e residual dust from the beaker was designated as greater th an five microns, and the fines from the siphoned liquor, as less than five m icrons in effective diam eter. T he sedim entation procedure was based on the settling rate of quartz to give the separation at the five-micron size. Any m aterials present w ith densities appreciably greater or less th an th a t of quartz would accordingly be separated at sm aller or larger effective diam eters of the particles. Actual particle-size distribution counts were made on both fractions of a few samples selected at random. On the average, the fine fractions were found to have 89 percent of the particles sm aller th an 5 m icrons in diam eter, and 99 percent sm aller th a n 10 microns. In the coarse fractions the count of particles over 5 microns averaged somewhat more than 50 percent of the total, and 80 percent, on the average, w ere greater th an 2.5 m icrons in diam eter. D ue to the m uch greater density of iron and steel, the fractionating procedure separated p articles of these m aterials into greater th a n an d less th a n 2.5 m icron size fractions. T h e relatively large num ber of particles betw een 2.5 and 5 m icrons in diam eter in th e coarse fractions is indicative of th e large proportion of fine particles of iron, steel, or other heavy m aterials in the samples. It is believed th a t the separation of quartz into fractions above and below 5 microns in diam eter was well accomplished. Free Silica T he X -ray diffraction technique was used for the determ ination of free silica (q u artz) in all samples which were separated into the two particle-size fractions and in a few other samples. Beryl was used as an internal standard for the quantification of the photographed pattern. Some samples required treatm ent with a dilute acid for the rem oval of interferences, principally iron. T h e instrum ent used was a G eneral E lectric X R D , ty p e 1, X -ray diffraction ap p aratu s. T h e film densities were read on a Leeds and N orthrup recording m icrophotom eter. M ost of the determ inations of free silica in parent m aterials and rafter dusts were done by a modified phosphoric acid procedure (9 ). T he m ethod depends upon both tim e and tem perature control during the acid treatm ent. This m ethod has been found to be accurate and rapid for sam ples such as were encountered in this study. 26 Iron D epending upon the size of the sam ple and the iron content, two m ethods were used in the determ ination of iron. Some sam ples were analyzed by both methods. Samples containing relatively large quantities of iron were analyzed by a titrim etric procedure (1 0 ). T he iron was separated by a precipi tation as the hydroxide which was then dissolved in acid. T he iron was reduced with stannous chloride and the excess of the reducing agent oxidized by m ercuric chloride. T he ferrous iron was then titrated with a standard solution of potassium dichrom ate using diphenylam ine indicator. Some air-borne m aterials collected by means of the electrostatic precipitator and other m aterials low in iron were analyzed for iron by a colorimetric m ethod ( 1 1 ). T he samples were treated with hydro fluoric and perchloric acids and ashed. T he ash was taken up in hydro chloric acid, filtered and diluted to volume. An aliquot was treated with alpha-alpha-dipyridyl reagent and the color read in a photoelec tric spectrophotom eter at 522 millimicrons. T he iron concentration was read from a standard curve of transm ission values determ ined from a series of iron standards treated by the same procedure. Lead Only a few sam ples were analyzed for lead. These were all electro static-precipitator samples for dust or fume. T hey were rem oved from the tube by washing with 30 percent alcohol-water solution and were ashed w ith nitric acid. T he determ inations were m ade by a double extraction, mixed-color dithizone procedure (1 2 ). The color was m easured at 510 millimicrons by a photoelectric spectrophotom eter. HesuEfs of Envirorcruierifcii Studies A TM O SPHERIC CONTAM INANTS-- Dust Characteristics Foundry dusts, in general, consist of a m ixture of various inorganic m aterials and a small am ount of organic substances (1 3 ,1 4 ). Free silica ( S i 0 2) is an im p o rta n t co n stitu en t of th is m ixed d u st w hich originates principally from the molding and core sands. Analysis of 30 molding sands and 10 core sands tak en from various foundries showed an average of 75 percent free silica in m olding sand and an average of 86 percent free silica in core sand. P arting com pounds furnish another source of silica dust, and an analysis of 16 of these m aterials showed a range of from 0.5 to 93 p ercen t free silica. T h irte e n of th ese com pounds 27 contained less than 8 percent; w hereas the other three contained more than 63 percent free silica. f r e e s il ic a i n a ir -b o r n e d u s t .-- T a b le 2 show s th e p e rc e n t b y weight of free silica in the air-borne dust by operation for the total sam ple and for th e fraction less th a n five m icrons in size. R ange and m ean values are shown. The m edian values were essentially the same as the mean. T able 2.-- Percent b y weight of free silica in air-borne foundry dust in 18 ferrous foundries in Illinois according to operation Operation Number of samples Free silica percent by weight Total sample Fraction less than 5 microns Range Mean Range Mean Coremaking 5 8-21 13 6-18 12 Molding _ _ 15 13-46 26 5-39 15 Pouring 3 18-44 29 11-25 21 Shakeout and sand conditioning___ 10 20-40 29 11-44 17 All cleaning operations _ 12 10-27 17 12-33 18 T hese data show th a t the average percentages of free silica in the total sam ple for molding, pouring, and shakeout operations were essen tially the same, probably because these operations are conducted in the sam e general area. It is interesting to note th a t in these operations th e m ean p ercen t of free silica in d u st less th a n five m icrons in size is appreciably lower than was found for the total sample. Com putations using data from the text table on page 29 and table 2 show the per cent of free silica in th e dust less th an five m icrons in size to be approxim ately one-half the percentage found in the fraction above five m icrons in size. T h e average percent of free silica in the total sam ple was only about half as high in the corem aking and cleaning operations as com pared w ith the other operations. No significant differ ence was found in the percent of free silica in the tw o size fractions in coremaking and cleaning operations. f r e e s il ic a i n s e t t l e d d u s t .-- T h is w as d e te rm in e d from sam ples collected from overhead pipes and beam s a t least 20 feet above floor level. T hese samples were collected in the following areas: (1 ) core making, (2 ) cleaning, and (3 ) molding, pouring, shakeout, and sand conditioning. Since the last operations are all carried out in the same location, the sam ple represents a com posite dust from all these opera 28 tions. T he results of analysis of these sam ples for free silica are as follows: Area Number of sam ples F ree silica percent b y weight Range M ean C o r e m a k in g ................................................................ 11 18-62 30 C leaning ..................................................................... 15 21-53 30 M olding, pouring, shakeout, and sand con- d itioning ................................................................ 28 12-51 30 B y a coincidence, the average am ount of free silica in the settled dust from the three areas was found to be 30 percent in each case. T he results were practically identical with those of the air-borne dust for molding, pouring, shakeout, and sand conditioning (table 2). An appreciable difference was noted in the percent of free silica found in air-borne and settled-dust samples from coremaking and cleaning operations. T hese results indicate th a t considerable caution is required in using settled-dust sam ples to evaluate the com position of a mixed air-borne dust for any individual foundry. Apparently, differential settling of a mixed-density dust has an influence on the com position of settled rafter dusts. If settled dust sam pling is done, it is im p o rtan t th at representative samples be collected and that a large num ber be ta k e n to insure m axim um reliability. F ro m th e d ata obtained, it is evident that further study of the relationship of settled dust to air borne dust is needed. ir o n .-- T o g e th e r w ith its com pounds, iron w as also ev a lu ated as a constituent of the foundry dust. Results of the analysis of dust samples, collected w ith the electrostatic precipitator, for iron are shown in tab le 3. A review of tab le 3 shows th a t the iron content of air-borne T able 3.-- P ercent b y w eight of iron and its com pounds (expressed as F e) in air-borne foundry dust in 18 ferrous foundries in Illinois according to operation Operation Number of samples Ir on percent t>y weight Range Mean Molding _ 7 3- 7 5 Melting and tapping _ 6 4-15 9 Pouring _ 15 4-13 8 Shakeout _ _ _ _ 11 2- 7 3 Stand grinding _ 8 8-59 38 Pneumatic chipping and grinding 8 13-51 30 29 dust was considerably higher at cleaning operations (stand grinding, and pneum atic chipping and grinding) than at other foundry activities. In view of the nature of cleaning operations, these high results were to be expected in the vicinity of the operation. (Tw o sam ples col lected at welding and burning operations showed 39 and 40 percent of iron, respectively. T he operation studied is not routine as a general rule except in steel foundries.) T he iron content of the general room air and settled dust in casting cleaning departm ents was found to be as follows: Type of dust Number of sam ples Percent iron Range M ean A ir -b o r n e ..................................................................... 3 7-30 18 S ettled ....................................................................... 5 8-22 16 A com parison of the iron concentration in the general room air and th at found in the im m ediate vicinity of specific cleaning operations (table 3) indicates that differential settling takes place very rapidly, th e iron decreasing from 38 or 30 p ercen t to ab o u t 16. l e a d .-- T h re e sam ples for lead w ere collected a t one fo u n d ry w here patterns were m ade from white m etal which contained approxim ately 75 percent lead. R esults of analyses showed 0.06 m illigram of lead per cubic m eter of air at m elting and 0.007 milligram at the finishing operation, which included grinding and routing. Inasm uch as lead exposures in the ferrous foundries studied were interm ittent and only rarely encountered, it m ay be concluded that lead does not constitute a significant hazard in this industry group. RELATION OF p a r t ic l e s iz e t o w e ig h t .-- T h is w as d e te rm in e d from air-borne dust collected w ith the vacuum cleaner in the vicinity of various operations. T he samples were elutriated, and the percent by w eight of th e dust less than five m icrons for the various operations was found to be as follows: O p eration Number of sam ples Air-born e dust percent b y weight Range M ean Corem aking ............................................................. 5 25-56 46 M o l d i n g ....................................................................... 15 2-64 30 Pouring ....................................................................... 3 46-50 47 Shakeout and sand c o n d itio n in g ...................... 10 3-48 23 C leaning operations ............................................... 12 6-72 32 It will be observed th at the greatest percentage of particles less than five m icrons was found in the pouring and corem aking opera- 30 Percent equal to or less than a stated particle size 99.5 99 98 95 90 80 70 60 50 40 30 20 I 0 0.1 0.2 0.3 0.4 0.6 0.8 1.0 2.0 3.0 4.0 6.0 8.0 10.0 Particle size in microns 00 Figure 12.-- Particle-size distribution of a typical air-borne foundry dust. tions. T he lowest average value of 23 percent, which was obtained during shakeout and sand cutting, m ay possibly be explained as result ing from the projection of large particles from the relatively dry sand during extraction of the castings. Similarly, corem aking operations are of such a nature th a t large particles are less likely to be throw n into the air. p a r t ic l e -s iz e d i s t r ib u t i o n .-- T h is w as d e te rm in e d for 12 sam ples prepared as previously described. W hile these samples were not col lected in all 18 foundries, th e y w ere selected to give a representative sam ple of th e conditions encountered. F ig u re 12 p resen ts th e particlesize distribution of a typical air-borne foundry dust. T he probable percentage of particles w ithin a certain size range m ay be determ ined from such a curve. T h e geom etric m ean, w hich is th e m id p o in t size in the distribution, is located at the intersection of the curve w ith the 50 percent line. T able 4.-- Particle-size distribution of 12 sam ples of air-borne fo u n d ry dust in ferrous foundries in Illinois according to operation Sample No. Operation Geometric mean of total sample (microns) Percent of total sample equal to or less than indicated size 3 microns 1.5 microns 0.9 micron 1 Coremaking 0.5 99 92 73 2 Machine molding .8 93 83 64 3 Machine molding .7 99 88 67 4 Floor molding .6 95 84 70 5 Manual shakeout 1.7 73 54 28 6 Mechanical shakeout 1.6 90 54 15 7 Mechanical shakeout and sand conditioning _ 1.2 94 74 28 8 Manual and mechanical shakeout _ 1.4 94 62 14 9 Sand conditioning 1.4 86 62 34 10 Cleaning _ .8 97 83 61 11 Cleaning .6 98 84 64 12 Cleaning _ .5 99 93 76 N ote: Sam ple num bers 3 and 7 were taken at steel foundries, the others a t gray iron foundries. T able 4 sum m arizes the data on particle size m easurem ents of the 12 sam ples. E x cep t for tw o of th e sam ples, 90 p ercen t or m ore of all particles w ere three m icrons or less in size. T here is a noticeable difference, however, in the particle-size distribution of dust from shake out and sand conditioning as com pared w ith dust from molding, core 32 making, and cleaning operations, the geometric m ean being about twice as high in the shakeout and sand conditioning group. This dif ference in size distribution is particu larly striking in th e group of 0.9 m icron or less. D ust Concentrations T able 5 shows the dust levels found at coremaking, molding, and pouring operations. W ith the exception of operations where sand slingers were used, the average dust concentrations were low-- all under three million particles per cubic foot of air. W ith respect to m olding operations, regardless of the type-- bench, floor, or m achine molding-- there was little difference in the dust concentrations found. On the average, dust concentrations at coremaking and pouring opera tions were lower than at molding. M achine corem aking showed higher average concentrations than hand operations. T able 5.-- D u st concentrations in corem aking, m olding and pouring de partm ents in 18 ferrous foundries in Illinois, according to operation Department and operation Number of samples Millions of particles per cubic foot of air Range Median Mean Coremaking department Bench coremaking Floor coremaking _ Machine coremaking _ _ Molding department Bench molding _ _ Floor molding _ Machine molding Sand-slinging _ Sand-slinger mold finishing Pouring department 56 0 .1 -5 .2 1.3 1.6 39 0 .1 -5 .2 1.2 1.5 9 0.1-3.6 1.1 1.3 8 0.9-3.5 2.6 2.3 155 0.1-58.4 3.1 4.0 24 0.1-10.1 2.1 2.7 40 0 .1 -6 .2 2.7 2.6 57 0 .4 -7 .6 2.5 2.6 14 2.8-58.4 12.2 19.1 20 1 .4 -7 .7 4.6 4.7 32 0 .1 -4 .2 1.9 1.9 T he range of values found at coremaking, molding, and pouring operations is v ery narrow w hen the 14 sam ples collected a t sandslinging operations are om itted. T he highest dust concentration in the rem aining 229 sam ples w as 10.1 m illion p articles p er cubic foot of air. Sand-slinging show ed a range of from 2.8 to 58.4 m illions of p ar ticles p er cubic foot w ith a m ean value of 19,1. 33 An im portant source of dust at molding operations was the dry parting compounds. Tim e studies of m achine molding showed th at it required about 3 m inutes to m ake a mold; of this time, one-half m inute was used in applying the parting compound. D uring the course of a w orkday, m ore th a n an h o u r's tim e w as sp en t a t th is d u sty operation. T h e results of a tim e stu d y of a m achine m o ld er's d u st exposure, as m ade by the Public H ealth Service some years ago, are as follows (1 5 ) : A ctivity Tim e of exposure in m inutes per 9-hour day (A ) Average dust expo sure in m illions of particles per cubic foot (B ) M illions of particle m inutes ( A x B ) Parting compound application. 86 Pouring ............................................ 34 R em ain in g t a s k s ........................... 420 T otal .................................. 540 25 2150 2.5 85 2.0 840 3075 3075/540 -- 5.7 m ppcf weighted exposure; 2150/3075 -- 70 percent of exposure due to application of parting compound. Thus, the dust concentration during the application of the parting com pound was over 10 tim es th a t observed a t pouring and other tasks. T he significance of this concentration becomes evident when th e particle-m inute exposure of this job is com pared w ith the to tal particle-m inute exposure of the occupation. The im portant fact revealed is th a t the parting com pound contributes 70 percent of the m older's exposure. If th e p artin g com pound co n tain ed little or no free silica, th e w eighted exposure w ould rep resen t only ab o u t 0.5 m illion particles of free silica per cubic foot of air. In this case, the parting com pound contained over 90 percent free silica, and the w eighted exposure represented about 4.5 m illion particles of free silica per cubic foot of air. As previously m entioned, th ree of 16 Illiriois foundries were found to be using a high-silica parting com pound. Since highsilica parting com pounds have received m uch adverse publicity in past years, it was surprising that they were still used in some plants. Table 6 shows the dust concentrations found at shakeout and sand conditioning operations. In a few foundries molding, pouring, and shakeout were done m ore or less continuously. However, in the m ajority of plants, shakeout and sand treatm ent were done at night after all other operations had ceased. Generally, the men who did the shakeout also prepared the sand after the castings had been rem oved from the sand molds. It m ay be observed from these d ata that, in general, the shakeout jobs produced far more dust than the sand preparation jobs, and the m echanical m ethods of perform ing a task produced from tw o to five tim es as m uch dust as the m anual m ethod of operation. 34 T a b le 6.-- D u st concentrations in sh a keo u t and sand conditioning d e partm ent in 18 ferrous foundries in Illinois, according to operation Operation Number of samples Millions of particles per cubic foot of air Range Median Mean Removing flasks manually _ 27 0.1-27 2.6 3.6 Removing flasks with chain or elec- trie hoist 19 .6-99 6.1 10.8 Dragging-out; knocking-off risers and removing cores manually 44 . 1-38 2.7 4.7 Dragging-out with a hoist and re- moving cores with sledge hammer _ 22 1.0-240 6.3 22.9 Shaking-out castings with a vibrator hoist 13 2.2-341 12.0 75.5 Shaking-out on a mechanical vibra- tor platform 18 .6-39 8.7 11.0 Cutting and raking sand manually. __ 15 .1-7.7 2.1 3.1 Cutting sand with small riddlers 19 .9-30 4.5 7.0 Cutting sand with a disk 12 .2-7.5 2.9 3.1 Clean-up and odd jobs of very short duration 33 .1-9.7 1.8 1 .9 T he dust concentrations found at the various operations in the abrasive cleaning d e p a rtm en t are show n in ta b le 7. T h e highest av e r age concentrations were found at portable grinding and the com bina tion job of grinding and chipping. U nlike portable grinding, swing fram e grinding was a discontinuous operation in the plants studied. T a b le 7.-- D u st concentrations in abrasive cleaning d e p a rtm en t in 18 ferrous foundries in Illinois, according to operation Operation Number of samples Millions of particles per cubic foot of air Range Median Mean Stand grinding Portable grinding Portable grinding and pneumatic chipping Pneumatic chipping Swing grinding Wheelabrading _ Abrasive blasting (cabinet method) __ Tumbling 43 0.2-94 23 .2-51 13 1.1-49 17 .1-10 15 1.3-46 15 .5-11 10 .4-26 20 .7-15 2.9 6.9 10.1 15.3 6.4 12.8 2.7 3.2 3.1 6.6 2.6 3.3 2.1 5.6 2.6 3.2 35 T he short period of operation did not perm it a buildup of dust, even though exhaust ventilation was not employed. T he average dust con centration at stand grinding, wheelabrading, abrasive blasting, and tum bling was influenced by the use of m echanical exhaust ventilation. T able 8 shows the dust concentrations observed at the various tasks perform ed in the m elting departm ent. W ith the exception of the one task of chipping-out the cupola, the m ean dust concentrations ranged from 1.2 to 3.7 m illion p articles p er cubic foot of air. T h e cu p o la chipping operation, w hich lasts 30-45 m inutes per day, is perhaps the dustiest of all foundry operations studied. T able 8.-- D ust concentrations in m elting d ep a rtm en t in 18 ferrous foundries in Illinois, according to operation Operation Number of samples Millions of particles per cubic foot of air Range Median Mean Chipping-out cupola 13 4.2-487 88.4 123.5 Mudding cupola. _ 6 .1-10.5 2.4 3.3 Charging cupola 28 .1-3.2 1.1 1.2 Tapping cupola 32 . 1-9.1 1.9 2.2 Cleaning around cupola _ 14 .1-13.5 1.8 3.7 In addition to the plant activities thus far described, there are certain functions perform ed outdoors which are grouped as yard activities. Among these, a relatively infrequent one is unloading sand from railroad cars. In all of the plants studied, this very dusty opera tion was perform ed manually. T hree samples collected showed dust concentrations ranging from 62 to 121, w ith an average of 83 million particles per cubic foot of air. O ther yard activities, such as preparing charges for the cupola, and unloading scrap and other m aterials from railroad cars, have low dust exposures. T w enty-four sam ples ranged from less th a n 0.1 to 4.9, w ith a m ean of 0.9 m illion particles per cubic foot of air. Table 9 shows frequency distributions of dust concentrations accord ing to departm ent and operation. Of the 721 sam ples shown in the table, 141, or ab o u t 20 percent, w ere in th e range from 0.0 to 0.9 million particles per cubic foot of air; 260, or about 36 percent, were in th e range from 1.0 to 2.9 m ppcf; an d 190, or ab o u t 26 p ercent, w ere in th e range from 3.0 to 6.9 m ppcf. Thus, 82 p ercen t of th e sam ples collected for these specific operations showed dust concentrations of 6.9 m ppcf or less. O nly 4 percent of these sam ples w ere above 31,0 mppcf. 36 T able 9.-- F requency distributions of d u st concentrations in 18 ferrous foundries in Illinois according to departm ent and operation N um ber of sam ples w ith indicated range of m illions of particles per cubic foot of air Operation Total 0.0-0.9 1.0-2.9 3.0-6.9 7.0-14.9 15.0-30.9 31.0-62.9 63.0 or over Coremaking Departm ent Bench coremaking _ 39 19 14 6 0 0 0 0 Floor coremaking - __ 9 3 5 1 0 0 0 0 M achine coremaking _ 8 1 4 3 0 0 0 0 M olding Departm ent Bench molding- - 24 5 10 8 1 0 0 0 M achine molding __ .. 58 10 24 23 1 0 0 0 Floor m old in g____ __ .. _ _ 40 5 18 17 0 0 0 0 Sand-slinging ._ _ _ 14 0 1 0 7 4 2 0 Sand-slinger mold finishing 20 0 4 12 4 0 0 0 M elting Departm ent C hipping out cupola __ 13 0 0 1 0 2 3 7 M udding cu p ola___ _- 6 3 0 2 1 0 0 0 C harging cu p ola- __ ' 28 12 15 1 0 0 0 0 T ap ping cupola _ _ __ __ 26 5 17 4 0 0 0 0 Cleaning around cupola- _ 14 3 6 3 2 0 0 0 General indoor activities 24 6 11 7 0 0 0 0 Outdoor activities __ 20 13 6 1 0 0 0 0 Shakeout and Sand Conditioning Departm ent Rem oving flasks, m anually _ 27 6 8 10 2 1 0 0 R em ovin g flasks, m ech an ically___ 19 1 3 7 6 1 0 1 D ragging ou t m a n u a lly ___- __ 44 7 17 12 6 2 0 0 Dragging out m echanically- 22 0 7 4 3 4 2 2 Shakeout w ith vibrator h o i s t - ___ 13 0 1 2 4 2 1 3 Shakeout on vibrator p latform ___ 18 1 2 4 6 4 1 0 C u ttin g sand, m anu ally- __ _ 15 3 7 3 2 0 0 0 C utting sand with riddlers _ _ 19 1 6 6 3 3 0 0 C utting sand with disc _ - _ 12 2 4 5 1 0 0 0 Odd jobs-- _ _ __ -_ 33 11 18 3 1 0 0 0 Cleaning Departm ent Stand grinding __ __ 43 10 13 15 1 2 1 1 Portable grinding 23 1 3 7 4 4 4 0 Grinding and chipping 13 1 1 5 3 2 1 0 Pneum atic chipping 17 3 8 5 1 0 0 0 Swing grinding- _ 15 0 7 4 3 0 1 0 W heelabrading _ 15 2 8 3 2 0 0 0 Abrasive blasting _ 10 3 3 1 2 1 0 0 Tum bling, _ 20 4 9 5 2 0 0 0 37 O bviously the greater proportion of the values for the specific operations was in the lower ranges, w ith a few exceptions. D ust concen trations for sand-slinging and chipping out cupola operations fell in the higher ranges. T he values for dragging out castings mechanically, shakeout with vibrator hoist, shakeout on vibrator platform , and portable grinding were m ore or less evenly distributed throughout the various ranges. Occupational W eighted Exposures W eighted d u st exposures are show n in ta b le 10 for certain occupa tions and occupational groups. T he latter was formed principally to facilitate the correlation of the environm ental findings w ith the results of the medical investigations. D a ta show n in ta b le 10 w ere o b tain ed b y th e follow ing pro ced u res: the first step in all columns involved the calculation of occupational w eighted dust exposures for each occupation. F or example, if at a certain plant in a given job the workm en spend 5 hours a day at task A, w here th ere is an average dust concentration of 6 m illion particles per cubic foot, 2 hours a day at task B, w here there is a dust concen tra tio n of 25 m ppcf, an d 1 hour a d s y a t ta sk C, w here th e d u st con centration is 2 mppcf, the w eighted dust exposure for this occupation in th at plant would be: (5 X 6) + ( 2 X 25) + ( 1 X 2 ) = 1M 5 mppcf T he second step for columns A and C involved calculating a m edian dust exposure using all occupations that fell within a broad occupa tional group in all 18 plants surveyed. T h e occupational w eighted dust exposures were arrayed in ascending order of dust concentration. For each occupational weighted dust exposure the num ber of men repre sented by that exposure was entered. The median dust concentration value was the dust exposure of the m iddle m an in the array. In colum ns B and D only certain specific occupations were selected. Again m edians were calculated from the occupational weighted dust exposures for these occupations. I t is ap p a re n t th a t d ata in colum ns A and C do not represent a sum m ation or average of the values shown in colum ns B and D. I t m ay be seen from tab le 10 th a t th e values for th e specific occupa tions at gray iron foundries (colum n B ) and at all foundries (colum n D ) are essentially the same except for certain casting cleaning opera tions, portable grinding and chipping, swing grinding and cabinet abrasive blasting. T he exceedingly high value shown for mechanical shakeout by crane hoist with vibration (98.6) represents an operation encountered in only one plant where large castings were allowed to cool several hours with the result that the sand became dry and shake out of these castings was very dusty. 38 Table 10.-- M edian weighted dust exposure in gray iron and 18 ferrous foundries in Illinois according to occupational group and certain operations Occupational group and operation Millions of particles per cubic foot of air Gray iron foundries All ferrous foundries Col. A Col. B Col. C Col. D Coremaking Bench coremaking Floor coremaking Machine coremaking _ 1.0 1.1 1.4 1.7 1.0 1.0 1.9 2.0 Molding, 2.7 2.5 Bench molding 1.6 1.6 Floor molding 3.1 2.8 Machine molding. 2.0 2.5 Sand-slinging __ 7.8 9.5 Sand-slinger mold finishing and closing _ 5.4 3.4 Shakeout and sand conditioning 3.2 3.3 Manual shakeout _ 3.3 3.3 Mechanical--chain hoist _ 2.6 2.6 Mechanical--electric hoist with vibration 6.5 6.5 Mechanical--vibrating platform 8.1 8.1 Mechanical--crane hoist with vibration 98.6 98.6 Sand conditioning _ 3.0 3.7 Casting cleaning and finishing _ 2.7 2.4 Stand grinding 1.9 3.0 Portable grinding and pneumatic chipping _ _ _ 7.0 2.7 Swing grinding _ 5.8 1.9 Wheelabrading _ 1.9 2.2 Tumbling 3.1 3.1 Cabinet abrasive blasting __ 4.5 8.2 M aintenance and supervisory e mployees _ _ .9 Laborers and others __ 2.1 39 A TM O SPH ER IC CO N TAM INANTS-- Gases Irritant Gases Smoke and gases are produced by certain foundry operations and tend to contam inate the working environment. The principal opera tions evolving these contam inants are the baking of cores and the pouring of m olten m etal into the molds. In both operations the smoke and gas evolved were a result of the pyrolysis of the organic m aterial incorporated into the cores, and, to a small extent, also present in the molding sand. Various aldehydes were the most im portant of these irritant gases. At the core-baking operation, the baking ovens were of tight con struction and were usually vented to the outdoors. Some of the ovens were equipped w ith canopy hoods which were m echanically exhaust ventilated. No perceptible am ounts of aldehydes were detected escap ing from the ovens into the workrooms except in one instance. In this case, however, baking of the cores was done at night, and no workers were exposed to the gaseous environment. Tw elve tests were m ade to determ ine the range of concentration of these different aldehydes during pouring operations. T he concentra tions ranged from an insignificant value to 3.3 p arts of gas per m illion p a rts of air b y volum e. T h e average v alu e w as 1.1 p a rts p er m illion. These concentrations existed only for the duration of the pouring operation. Carbon M onoxide Gas A nother im portant contam inant of foundry atm osphere is carbon monoxide gas. It was present in the gases and smoke which were produced by the pyrolysis of organic m aterial. A bout 150 m easure m ents of carbon monoxide concentrations were m ade around cupola operations and also during pouring operations. T he concentration of carbon m onoxide ranged from 0 to 75 parts of gas per m illion parts of air at the tapping station of the cupola. T he concentration of carbon monoxide ranged from 0 to 50 parts per million at the charging station of the cupola, except at those plants where the charging station was partially enclosed. In such instances, the carbon monoxide concentra tion ranged from 100 to 400 parts per million. However, since the operation occurred only interm ittently and was of brief duration, with a to ta l tim e of exposure of less th a n 1 hour p er shift, th e w o rk er's exposure was short. M ost of the determ inations were m ade at pouring operations where the largest num ber of workers were involved. Concentrations were consistently low during the sum m er m onths when natural ventilation was at an optim um. At those times, the levels of carbon monoxide 40 ranged from 0 to 200 parts per million. In all cases, the average daily exposure was well below 100 parts per million. T here was no apparent correlation betw een th e size of the m old an d concentration of the gas, probably because of the influence of good natural ventilation when the doors and windows were open. D uring the colder months, when doors and windows were kept closed, the levels of carbon monoxide during pouring increased to a range of 100 to 600 parts per million, w ith m om entary levels as high as 800 parts per million. T he size of the m old or the am ount of coring in the m olds appeared to have less influence on the levels of carbon monoxide than the size of the space in which the operation was per formed. T he duration of exposure to carbon monoxide was lim ited to the pouring time, which usually did not exceed an hour. Even with the short duration of exposure, there was evidence of a hazard during cold weather. DISCUSSION OF A TM O SPH ERIC CONTAM INANTS I t is of interest to consider th e possible reasons for the com paratively low dust concentrations found in th e 18 Illinois foundries studied. D ust concentrations found were definitely lower than those reported in earlier investigations (1 6 -1 9 ). Except for the study m ade in A ustralia, th e investigations referred to w ere m ade m ore th an 10 years ago. It would be valuable to have a re-study of the foundries covered in these earlier investigations to ascertain w hether there has been any appreciable change in dust concentrations. Interestingly enough, engineering investigations of foundries (2 0 ) conducted since the com pletion of the field work of this study showed dust concentrations very sim ilar to those contained in this report. Subsequent to the com pletion of the field study in Illinois, inspec tions were m ade by an engineer of the Public H ealth Service in a num ber of foundries in two other states. Visual observations indicated apparent dust concentrations of the foundries in one of these states to be of the same order of m agnitude as found in th e Illinois foundries. Studies m ade by the State corroborated this observation. In the other state the foundries visited were observed to be considerably more dusty, and, except in a few instances, m odern m ethods of operation were lacking. S ta te records of investigations over th e last 12 y ears con firmed these impressions. Although there are wide variations in foundry practices, not only from state to state but also within any given state, there is reason to believe that, in general, there has been a gradual im provem ent in the control of atm ospheric contam inants in the foundry industry. New techniques of operation have been developed which are not only more efficient b u t which also lend them selves m ore readily to dust-control 41 methods. Equipm ent m anufacturers have developed and prom oted the use of new and more effective devices for the control of air contam i nants. In addition, official agencies have prom oted m easures designed to im prove working conditions. Factors Influencing Foundry Environm ent T here are m any factors which influence the foundry environm ent. Some of these m ay be referred to as follows: a c t iv it y a n d s p a c e .-- T h e degree of a c tiv ity has a g re a t effect on the concentration of atm ospheric contam inants. Since production, and consequently em ployment, varies with business conditions, the num ber of m en working in a given area m ay differ considerably over a period of tim e. T he am ount of floor area in the foundries studied varied from less than 200 to over 1,000 square feet per worker. Since productivity and em ploym ent in the foundries studied were at a high level, this factor does not offer an explanation for the low dust concentrations found. l o c a t io n a n d s c h e d u l in g o f o p e r a t i o n s .-- As p re v io u sly m e n tioned in this report, dust produced by one operation m ay affect the environm ent in adjoining areas. For example, settled dust in core m aking was found to be of the sam e average free silica content as in other foundry areas, even though the free silica content of dust pro duced by corem aking operations was m uch lower. Similarly, it was observed th at a particularly dusty operation influenced the dust level throughout the building. Consequently, where shakeout was done on all shifts, all workers were exposed to more dust than was the case when shakeout was done at night. T he m ajority of the plants studied perform ed shakeout at night after most of the employees had left the plant. T his accounts, at least in part, for the low concentrations found at m any of the molding, coremaking, and pouring operations. s iz e o f c a s t in g s a n d t o n n a g e .-- I t w as o b se rv e d th a t th e size of casting influenced the dustiness of the foundry. This was particularly so in shakeout operations. Sm aller castings were usually rem oved im m ediately after pouring, while the sand was still com paratively moist. In the case of larger castings, the necessity to delay the rem oval of the casting for a longer period of tim e resulted in the sand drying out and more dust being produced at shakeout. On the other hand, for a given tonnage, shakeout of smaller castings m ay produce more dust because of the greater num ber of individual castings which are handled. Therefore, where comparisons of dust levels are made, based on the tonnage of m etal poured, due consideration m ust be given to the size of castings. d e g r e e o f m e c h a n iz a t io n .-- M ech an izatio n of fo u n d ry o p eratio n s results in increased dust production unless supplem ented by proper 42 control measures. W here shakeout and sand-conditioning operations were m echanized w ithout proper local exhaust ventilation, higher dust levels were observed. On the other hand, one of the most com pletely m echanized plants was found to have very little dust because adequate local exhaust ventilation was employed. v e n t il a t io n .-- N a tu ra l v en tila tio n is an im p o rta n t factor in re d u c ing th e level of atm ospheric contam ination. In large buildings with m onitors or saw-toothed roofs w ith adequate openings, and w ith am ple window area in the walls, dust concentrations were usually found to be lower. N atural convective drafts m oved through these openings and prevented a build-up of general contamination. M ost foundries were also equipped with mechanical exhaust roof fans. T he use of these fans during cold weather, when m ost doors and windows were closed, was an im portant factor in reducing general co ntam ination. G eneral ventilation is useful in preventing a build-up of high con centrations in the general workroom air. Local exhaust ventilation will prevent the release of excessive concentrations into the breathing zone of the worker as well as into the general atm osphere. V entilation of this type was em ployed in m any foundry operations; it was used in the cleaning departm ents of all foundries studied and in shakeout and sand-conditioning operations at some foundries. D ust concentrations were m aterially decreased where these exhaust systems were properly designed and m aintained. h o u s e k e e p i n g a n d s u p e r v i s i o n .-- T h e im p o rta n c e of good h o u se keeping practices as an adjunct in m aintaining low dust concentrations cannot be overemphasized. Accumulation of dust on overhead beams and rafters, as well as on m aterials stored in the foundry area, should be prevented. Storage of equipm ent in an orderly m anner and m ain tenance of floors and aisles free from debris are other factors influ encing the dust levels. Good housekeeping m easures were evident, w ith few exceptions, throughout the foundries studied. M aterials and supplies were stacked in designated locations, and, generally, there were well-defined aisles for passage of workers and equipment. M any of the plants rem oved settled dust from overhead pipes and beam s as well as from stacked supplies at periodic intervals to prevent redispersion of such accum ula tions by vibrations and drafts. Floors were generally kept free of excessive accum ulations of sand and dust. M any plants had concrete floors which facilitated good housekeeping. D irt floors were alm ost always hard-packed and kept w et to m inimize scuffing-up of dust. G ood housekeeping is an indication of good supervision. T he blam e for poor housekeeping m ust rest entirely on the shoulders of m anage ment. Furtherm ore, m anagem ent should see that proper techniques 43 are em ployed to prevent the unnecessary dispersal of dust from opera tions. F or example, due to lack of proper supervision in some of the foundries, certain m olders created clouds of visible dust through the im proper application of parting compounds. It was also observed th at the indiscrim inate use of com pressed air created excessive am ounts of dusts and th at im proper mixing and w etting of molding sand definitely contributed to the dustiness of some foundries. T he judicious use of w ater can do a great deal to reduce the am ount of dust getting into the general foundry atmosphere. T he proper am ount of m oisture during sand-conditioning operations, for example, will prevent the building-up of unnecessarily high dust concentrations. T here are other instances also where w ater can play an im portant part in keeping dust levels low. It was observed th at techniques em ployed at shakeout, and the scheduling of these operations, played an im portant p art in the dust produced. Recomm endations 1. L ocal exh au st v en tilatio n should be em p lo y ed w here m echanical shakeout equipm ent is used. 2. E x h au st ventilation should be em ployed w ith portable grinding operation. 3. E xhaust system s and dust-collection equipm ent should be given proper m aintenance at all times. 4. T he best possible housekeeping program should be enforced at all tim es. 5. H igh-silica (over 8 p erce n t) parting com pounds should not be used. 6. W here buildings are to be rem odeled or new ones built, considera tion should be given to locating the various operations in such a m anner as to minimize the num ber of workers affected by dust. 7. C onsideration should also be given to scheduling of operations, such as shakeout or sand-conditioning, in order to minimize the num ber of workers affected by a dusty operation. 8. A d eq u ate v en tilatio n should be p ro v id ed to p re v e n t excessive con centrations of carbon monoxide during pouring operations and around furnace charging. N O IS E T he environm ental study included an evaluation of sound intensities and frequencies. T he objective of this phase of the investigation was to determ ine these sound characteristics within the foundries studied. According to recent investigators, noise levels of intensities below 80 decibels are believed not to produce acute or chronic aural damage; b ut above this level, dam age m ay occur, the severity and incidence 44 of w hich is probably directly proportional to the intensity of th e noise (21, 22). T he am ount of aural damage seems to be correlated, further more, w ith the frequency of the sound. T he greatest effect occurs in the higher tonal levels and is p articularly pronounced in the frequency area of 4000 vibrations per second (23, 24). M ethods of M easurement Intensity readings were taken with General R adio sound level m eter type 795-B. An extension cable was used to minimize sound distortion a n d to facilitate th e m easu rem en t of sound a d ja c e n t to th e w o rk er's environm ent. M icrophones used were of the piezo-electric type utilizing a bim orph crystal. Sound frequencies were analyzed w ith a G eneral R adio sound analyzer type 760. Findings T a b le 11 shows th e ran g e a n d average noise level readings, in decibels, in twelve ferrous foundries in Illinois by location. These data are presented for each foundry and subdivided into three m ajor depart m ents-- coremaking, molding, and cleaning. c o r e m a k in g d e p a r t m e n t .-- S o und in te n sitie s in co rem ak in g departm ents are usually influenced by other operations located in the same general vicinity. For example, there was no separation of the core departm ent from the molding and cleaning departm ents in foundry No. 4, and, as a result, th e noise levels in th e core d e p a rtm e n t were considerably higher than in the core departm ents of other foundries. On the other hand, since the core departm ent in foundry No. 16 was separated from the cleaning d ep artm en t b y a w all having a high transm ission loss, a considerable reduction in noise intensities was found. T he two m ajor noise-producing sources in the core departm ent proper are coremaking machines and fans used to ventilate the core ovens. Four of the core departm ents studied did not have coremaking machines. Of this group, foundry No. 5 had the highest sound inten sities, which were due to the exhaust fan on the core oven. E xcept for No. 5, as show n in ta b le 11, higher noise levels w ere found in those core departm ents with core machines. T he frequency levels found in the corem aking departm ent varied considerably. In m any cases, the m ajor frequency resulted from the exhaust fan. In other cases, the m ajor frequency was due to com pressors and other m achinery located in adjoining areas. In still other instances, it was due to molding and cleaning operations. T he frequen cies were of a low order of m agnitude, about 100 cycles per second. m o l d in g d e p a r t m e n t .-- As in th e case of th e co rem ak in g d e p a rt ment, the physical location of the molding departm ent with regard to 45 4^ 0\ T able 11.-- M in im u m , m a xim u m and average noise level readings, in decibels, in 12 ferrous foundries in Illinois b y location Department and operation 1 fi Xfi C 2 3 ! C Xfi* fi S' <! s < 4 fi Xfi* < 5 fi fXi Foundry number 6 7 8 9 14 15 16 fi fXi fi fXi c fXi fi Xfi* fi Xfi fi Xc<3 fi cX3* <1 < if C <1 < < << Coremaking department: Bench coremaking Machine coremaking General room 78 80 79 68 76 73 70 86 74 84 91 88 72 76 74 64 68 66 62 68 64 66 68 67 68 74 71 68 72 70 68 74 70 56 58 56 78 80 79 70 76 74 75 86 78 86 91 88 -- -- -- 66 70 68 74 76 74 83 88 85 78 82 80 -- -- - 78 80 79 68 76 73 70 86 75 84 91 88 72 76 74 64 70 69 62 68 64 66 68 67 68 76 74 68 88 72 68 82 72 56 58 56 Molding department: Bench molding __ _ _ 70 72 71 72 90 75 70 80 72 78 82 80 66 68 67 79 82 80 74 79 76 66 70 68 68 72 70 50 59 56 Bench machine molding___ 75 81 78 75 94 76 -- -- -- 83 98 85 63 98 72 80 90 85 80 90 85 84 90 86 68 86 78 -- -- -- Floor molding 68 70 69 75 78 76 68 80 70 -- -- -- 65 67 66 76 81 77 66 70 68 79 82 80 80 84 82 66 72 70 68 82 76 48 58 52 Floor machine molding___ 68 92 69 78 82 80 -- -- -- Sand-slinging _ 68 70 69 (*) (*) (*) -- -- -- General room _ _ 75 81 78 72 90 76 68 80 70 83 86 85 63 68 66 79 82 80 66 92 68 79 82 80 74 90 82 68 72 70 68 72 70 48 58 55 Cleaning department: Swing grinding Stand grinding _ . Portable grinding Pneumatic chipping _ Tumbling Wheelabrading Roto blasting __ __ Sandblasting. Burning _ __ General room. (*) (*) n -- 84 86 85 -- -- -- -- -- -- 88 92 90 (*) (*) (*) (*) (*) n 91 93 92 96 98 97 72 84 80 90 94 92 86 88 87 80 82 81 76 80 78 76 88 80 72 86 74 (*) (*) (*) (*) (*) (*) (*) (*) H 85 96 90 96 98 97 -- -- -- 84 104 93 (*) (*) (*) -- -- -- (*) (*) (*) 80 88 84 -- -- -- 90 94 92 (*) (*) (*) (*) (*) n 85 96 94 84 104 94 (*) (*) (*) -- -- -- 92 106 94 90 96 92 82 90 88 92 94 93 (*) (*) (*) (*) (*) (*) 91 93 93 97 103 100 88 92 90 (*) (*) (*) 90 93 91 85 85 85 (*) (*) (*) 92 96 94 72 78 76 93 93 93 -- -- -- 79 84 80 76 78 77 -- -- -- 79 84 82 (*) (*) (*) -- -- -- -- -- -- 93 96 94 -- -- -- -- -- -- -- -- -- -- -- -- (*) (*) (*) -- -- -- -- -- -- -- -- -- (*) (*) (*) (*) (*) (*) -- -- -- (*) (*) (*) -- -- -- -- -- -- (*) :(*) (*) -- -- -- (*) (*) (*) 92 96 94 70 90 74 -- -- 80 86 82 -- -- -- -- -- -- 86 94 89 88 92 90 86 90 88 93 96 94 91 103 97 72 92 87 76 94 91 88 93 90 79 84 82 80 90 86 76 96 88 72 84 81 N ote: A dash indicates that the operation did not exist at the tim e of the survey. An asterisk indicates that the operation existed but no readings w ere m ade. N o readings w ere m ade in foundries 10, 11, 12, and 13. other operations had a distinct bearing on the noise level. T h is is again illu strate d in fo u n d ry No. 4, w here th e re is no physical sep aratio n b e tween the molding and the cleaning departm ents. T he same conditions a p p ly to No. 8. T h e sound intensities w ere considerably higher in these molding departm ents than in the others surveyed. However, in foundry No. 16, w here a w all w ith a high transm ission loss se p arate d th e m old ing departm ent from the cleaning departm ent, there was a considerable reduction in sound intensities. In fo u n d ry No. 6, th e m olding d e p a rt m ent was located next to the cleaning departm ent and separated by a w all having a low transm ission loss, w hich resulted in above average sound intensity in the molding departm ent. T he m ajor sources of sound-producing equipm ent in the m olding departm ent were bench and floor m olding m achines and sand-slinging m achines. T his is illus tra te d in fo u n d ry No. 7. W h en th e m achines w ere n o t in operation, the sound levels averaged 66 decibels, b u t when the floor m olding m achine was in operation, the intensity increased from 68 to 92 deci bels. In fou n d ry No. 9, high intensities w ere o b tain ed from th e large num ber of molding machines. T he sound frequencies in the molding room are extrem ely complex and very difficult to m easure. T his is due to the interm itten t opera tions of the various types of machines used in the molding departm ent and in some cases to the sounds originating from sources other than in the m olding area. T he frequencies were of a low order of m agnitude, about 100 cycles per second. c l e a n in g d e p a r t m e n t .-- C leaning d e p a rtm e n t operations, w ith o u t exception, were the greatest source of noise in the foundries studied. As m entioned previously, the cleaning departm ent frequently con tributed considerably to the noise of the other departm ents. T he clean ing departm ent of foundry No. 5 yielded higher sound intensities than the other foundries studied. T he departm ent was small, the walls were of stone construction, and num erous cleaning m achines were in operation within this small area. T here was no acoustical treatm ent w ithin the room, and the stone walls reflected the noise, thus pro ducing the high sound intensities observed. It is interesting to note that, because of the high transm ission loss of the walls in this p ar ticular foundry, the molding and core departm ents were relatively quiet. As would be expected, the sound frequencies were extrem ely complex and difficult to evaluate. T he frequencies ranged from 30 to 860 cycles per second. It was noted th at no type of acoustical treatm ent was used in any of the foundries studied. No attem pt was m ade to isolate particularly noisy machines or operations. W ith the exception of two or three indi viduals who p ut cotton in their ears, em ployees did not seem to use any personal protective devices to reduce noise levels. 47 Recomm endations 1. C onsideration should be given in all foundries to provide w alls w ith a high transm ission loss to separate the cleaning departm ent from the other departm ents. 2. E x h au st fans used in ventilating the core ovens should be properly designed, mounted, and m aintained to produce a m inim um noise level. 3. In foundries w here a series of m olding m achines are ad jace n t to each other and are located in a large area, proper sound condi tioning should be applied at appropriate areas to reduce the sound intensities. 4. P a rtic u la rly noisy m achines, such as th e tu m b lin g b arrels in th e cleaning departm ent, should be isolated w henever possible, or appropriate acoustical treatm ent should be em ployed where they are located. 5. W orkers in th e cleaning d ep artm en t, as well as th e m achine core m akers and sand-slinger operators in the molding departm ent, should w ear a proper type of ear plug. 6. A m ain ten an ce program should be enforced to keep th e eq u ip m en t in the optim um state of repair. ILLUM INATION A nother environm ental factor evaluated was illum ination. Since proper lighting is know n to play an im portant role in reducing eye strain, increasing production, and minimizing industrial accidents (2 5 -2 7 ), data on the quality and quantity of illumination were obtained in the present study. Light intensity readings were taken w ith a W eston M eter M odel 614 equipped w ith a Viscor filter. T he technique em ployed in m aking the readings was sim ilar to th at recom m ended by the Illum inating Engineering Society (28). Findings ------ T h e results of th e findings are p rese n ted in tab les 12 and 13. T h ere were num erous factors which influenced the light intensities in various foundries. These included the am ount of natural and artificial illumi nation, m aintenance of lighting systems, and reflection factors of walls, ceilings, and m achinery. Since all of these factors played an im portant part, it is impossible, in evaluating th e lighting conditions of any one foundry studied, to determ ine which factors had the greatest influence on the findings. Several of the foundries had saw-toothed, m onitor or skylight roof construction, which perm itted m axim um daylight illum ination in the interior of the building. In addition to window area in th e roof, a m ajority of the foundries also provided large window areas in the 48 Table 12.-- Average illum ination readings, in footcandles, in 14 ferrous foundries in Illinois, b y location operation Foundry number 1 2 3 4A 4B 5 6 7 8 9 10 13 14 15 16 Coremaking department: Bench coremaking__ _ 49 8 11 41 11 17 (*) 1 0 _____ 3 5 _____ 12 4 10 22 11 26 Machine coremaking___ 49 22 (*) -- 5 -- (*) -- -- 33 5 6 11 -- -- Floor coremaking _ _ _. -- (*) 3 14 -- -- -- 7______ -- -- 4---- 6 -- General room____ _ . _ 49 14 4 30 7 17 (*) 8______ 19_____ 23 4 6 15 9 9 Molding department: Bench molding _ _ 100 25 11 146 -- -- 3 26______ 1 2 _____ 20 2 3 6 12 10 Machine molding- _ 15 28 _ _ 32 74 15 5 _ 24 2 4 5 11 _ floor molding- _ __ 33 14 8 21 Sand-slinging____ _ _ _ _ 41 25 16 7______ 11_____ 22 10 10 11 10 8 7 _ 10 10 _ 10 _ General room___ _ . 42 17 9 53 32 34 11 12_____ 12______ 21 5 7 11 11 9 Cleaning department: Swing grinding-. __ -- -- 11 14 -- -- -- -- -- -- 6 4 10 -- -- Stand grinding__ . 18 (*) 11 6 11 20 20 Under 2 _ Under 2.. 35 6 3 5 11 6 Portable grinding. . 16 (*) 12 14 3 29 _ do 5 . _ 6 12 10 9 -- Pneumatic chipping. . . 16 (*) 12 14 3 -- ...d o ____ 5_______ -- 6 12 10 9 9 Tumbling.. . 23 (*) 10 5 2 2 5 do 4 28 _ 13 7 9 9 Wheelabrading__ 94 10 ...d o ____ 10 -- 4 5-- -- Rotoblasting _ . Sand blasting.. _ Burning__ . . . -- -- -- -- -- 12 -- -- _ (*) (*) 10 (*) _ -- -- -- -- -- -- -- 4 6-- -- 7 _ _ _ 1 _ 25 (*) -- 1 12 10 -- General room___ . 21 (*) 11 13 6 15 8 Under 2.. 4_______ 29 6 8 9 11 7 Note: A dash indicates that the operation did not exist at the tim e of the survey. An asterisk indicates that the operation existed but no readingss were m ade. N o readings were m ade in foundries 11 and 12. walls. N one of the windows was observed to be equipped w ith devices to regulate the am ount of light at the working level. In th e foundry industry it is p articu larly necessary to supplem ent natural illum ination with artificial lighting because the inherent dusti ness of the work reduces the transm ission of natural illumination. T a b le 13 shows th e ty p es of lam ps an d reflectors b y d e p a rtm e n t in the foundries studied. All reflectors observed were of the direct type. In the m ajority of the foundries the lighting systems were antiquated and. poorly designed. T o obtain m axim um benefit from illum ination sources it is necessary to m aintain proper reflection factors in the interior of the building. T he recom m ended reflection factors generally accepted are 90 percent for ceilings, 60 percent for walls, and 30 percent for m achinery. It m ay be seen in ta b le 13 th a t th e reflection factors found in th e foundries studied were considerably below these recom m ended values. T he im portance of proper m aintenance cannot be overemphasized. Systems which are adequate when installed deteriorate rapidly unless proper m aintenance is provided. A definite schedule of m aintenance work should be established to insure th a t wall and roof windows, 49 T able 13.-- Factors affecting artificial illum ination in the core, m olding and cleaning departm ents in 14 ferrous foundries in Illinois Foundry No. Department Type of lamp Factor Type of reflector Rejection factor (approximate percent) Ma Ceiling Wall chinery Maintenance 1 Core, molding, and cleaning __ Incandescent-.. Direct. 50 10 5 Fair. 2 do _ _do _ do _ 10 10 5 Good. 3 Core, and cleaning._ __ . . . d o . . __ _ do -_ 60 50 3 Molding__ _ . _ . . . Mercury____ _ . . . do__ 60 50 5 Poor. 5 Do. 4A Core.. __ __ __ Incandescent... ___do___ 20 20 10 Fair. 4A Molding, and cleaning___ _ Mercury______ ___ do___ 20 20 10 Do. 4B Core, molding, and cleaning__ Incandescent... ___do___ 20 20 10 Do. 5 : " . .do.. _____ . . . . .do. . ___ do 40 60 5 Fair. 6 Core, and molding.. _ ._ Incandescent. __ ___ do___ 20 20 10 Poor. 6 Cleaning___ Fluorescent____ ___do___ 20 20 10 Do. 7 Core.. . __ Incandescent _. ___ do___ 10 10 10 Do. 7 Molding, and cleaning. _ . . do. . _ None. . . 10 10 10 Do. 8 Core, molding, and cleaning ... Fluorescent. .. Direct.. 10 10 10 Do. 9 Core, and cleaning__ . _. Incandescent... ___ do___ 15 10 10 Good. 9 Molding. . ... Fluorescent and ___do___ 15 10 20 Do. incandescent. 10 Core, molding, and cleaning.._ Incandescent__ ___do ___ 15 30 10 Fair. 13 do _ -do do_- 30 30 10 Poor. 14 _ do _ do do _ 10 10 5 Fair. 15 Core, and molding. . . _do_ _ do_ _ 10 10 10 Do. 15 Cleaning___ . . ._ In c a n d e sc en t ___ do___ 10 10 10 Do. and mercury. 16 Core, molding, and cleaning__ Fluorescent and ___do___ 15 15 10 Poor. incandescent. N ote: N o observations w ere m ade in foundries 11 and 12. reflectors, lamps, and accessories are kept clean and in proper adjust m ent and good repair. One m ethod of determ ining how often this should be done is to check th e illum ination periodically w ith a light m eter. T he system should be m aintained so th a t the light intensities do not fall below 75 percent of the original intensities. A program for the group replacem ent of lam ps could be established in conjunction w ith the cleaning program . T he output of light decreases as the filam ent of a lam p slowly sublimes. R eplacem ent at 50 70 percent of average life is oftentim es ad o p ted as the econom ical point for group replacem ent, for a t this point less th a n 10 p ercen t of the lamps should norm ally have failed. T he m ost economical schedule will differ in accordance w ith conditions and requirem ents for each specific installation. R eco m m en d a tio n s 1. T o insure a m axim um of n a tu ra l illum ination in one-story b u ild ings, th e window area, including walls and roof, should be at least 30 percent of the floor area. 2. W indow s should be p ro v id ed w ith ad ju stab le devices to reg u late the quantity of light on the working area. 3. M o d ern lighting techniques should be em ployed to im prove a rti ficial illum ination. 4. P ro p er reflection factors should be provided on ceilings, walls, and m achinery. 5. An ad e q u ate program of m ain ten an ce should be in stitu ted . SANITATION FA CILITIES A san itation survey was conducted in 16 of th e 18 foundries studied. T h e survey did n o t include facilities provided for office w orkers or em ployees in departm ents other than those connected with foundry operations. Inform ation was obtained on the following item s: source of w ater supply, type of drinking w ater facilities, type of washing and toilet facilities, waste disposal, and adequacy and housekeeping of all sanita tion facilities. W ater Supply P u b lic w ater supplies w ere used in 13 plants, an d p riv ate supplies in th re e p la n ts for d rinking an d in d u strial purposes. O ne of th e 13 plants supplem ented the public supply w ith a private well. A pub lic w ater supply was available to 81.3 percent of the workers. Since these w ater supplies are under the supervision of the Illinois State D epartm ent of Public H ealth, no attem pt was m ade to determ ine their hygienic condition. D rinking W ater Facilities A pproved ty p e s of d rinking fo untains w ere p ro v id ed in 13 of th e 16 plants. Six of th e 13 p lan ts also p ro v id ed n o n-approved fountains in addition to the approved type. T hree plants provided only non approved fountains, which consisted essentially of faucets connected directly to the w ater lines. In addition to the nonapproved fountains, open-w ater containers were observed in two of these three plants. T he num ber of approved type drinking fountains was found to be adequate for the num ber of em ployees in the m ajority of the plants. 51 W ashing Facilities T he Illinois H ealth and Safety Act (2 9 ) and the American F o u n d ry m e n 's Code on S an itatio n ( 3 0 ) req u ire th a t th e following washing facilities be provided for employees: Number of employees per shift Number of lavatories 1 to 15 ......................................................................................... 1 16 to 30 ......................................................................................... 2 31 to 50 ......................................................................................... 3 For each additional 25 em ployees or fractional part thereof, there shall be provided 1 additional lavatory. T he lavatories m ay consist of individual units, wash sinks, or circular fountains. W here wash sinks or circular fountains are used, tw enty-four inches of outside rim of a wash sink and seventeen inches of a circular fountain shall be the equivalent of one lavatory. These two codes also require th at one shower be provided for each tw enty foundry em ployees per shift. H and-w ashing facilities were found to be adequate in all plants surveyed. All were equipped with hot and cold water, but two plants did not furnish soap. Although the codes do not require plants to supply towels, five plants furnished towels for hand washing. T hree plants were found to have one less than the required num ber of showers. Fifteen plants provided an individual clothes locker for each em ployee in the foundry area. Toilet Facilities T he following toilet facilities are required by the above codes: Number of employees per shift 1 to 9 ................. 10 to 24 ................. 25 to 49 ................. 50 to 74 ................. 75 to 99 ................. Over 99 ................. Number of toilets ............. 1 ............ 2 ............ 3 ............ 4 ............ 5 ........... I1 1 For each additional 30 em ployees. In addition to the num ber of toilets, 1 urinal is required for not less th a n 10 m en or m ore th a n 75 on an y 1 shift, w ith 1 ad d itio n al u rin al for each 75 men. Two plants provided 1 less urinal, and 4 plants provided 1 less toilet than required by the codes. All toilets and urinals were found to be standard flush type, and, in general, the space provided and the tem perature of the rooms were found to be satisfactory. 52 A num ber of the plants provided more washing and toilet facilities than the m inim um requirem ents and m aintained them in a very satis factory m anner. A few plants provided recreational facilities in the large shower or locker room. W om en were em ployed in the foundry areas in only two of the 16 plants surveyed. A dequate toilet and w ashing facilities were provided. W aste Disposal T h irteen of the 16 p lan ts discharged sewage and industrial w astes into m unicipal sewage disposal systems. Two plants discharged sewage and industrial waste, w ithout treatm ent, into nearby rivers; and 1 plant used a septic tank for treatm ent prior to discharging the waste into a stream. H ousekeeping G eneral housekeeping of locker rooms and toilet and washing facil ities was arb itrarily rate d as good, fair, or poor. A lthough th e 16 p lan ts were not surveyed by the same person, every effort was m ade to arrive a t com parable ratings. N ine of th e p la n ts w ere ra te d good; 2, fair; and 5, poor. Sum m ary In general, sanitation facilities provided for foundry em ployees were found adequate, and the m ajority were m aintained in a satisfactory manner. In a few of the plants surveyed, some im provem ents are needed with special reference to im proved housekeeping and the installation of additional facilities to m eet the minimum sanitation requirem ents. Summ ary of Environmental Studies F indings of the environm ental investigations m ade in 18 Illinois ferrous foundries are presented. T he data show the character and composition of parent m aterial and of air-borne and settled dusts; operational dust levels; occupational weighted dust exposures; and the concentration of other atm ospheric contaminants, such as alde hydes and carbon monoxide. M easurem ents of illum ination and noise levels, and an evaluation of sanitary facilities are presented and discussed. It was found th at 90 percent or m ore of the air-borne dust in all foundry environm ents w ere 3 m icrons or less in size. T h e am ount of free silica in the air-borne dust varied w ith the operation and ranged from 13 p erce n t a t corem aking to 29 p ercen t a t pouring, shakeout, a n d 53 sand conditioning. On the other hand, the free silica content in the settled dust was found to average 30 percent throughout the foundries. T he air-borne dust less than 5 m icrons in size was found to have a lower percentage of free silica than the larger size fraction. T he percentage of iron in the air-borne dust was found to range from 3 to 9 percent for all operations except casting cleaning, for which the proportion varied from 30 to 38 percent. O perational dust levels at various foundry activities in general were found to be m uch lower than those reported in earlier investigations. M ean dust levels at molding, pouring, and corem aking operations were found to be under 3 million particles per cubic foot of air. Sand-slinger m olding show ed a m ean d u st level of ab o u t 19 m ppcf. M echanical shakeout operations show ed m ean dust levels ranging from 10 to 75 m ppcf; w hereas m anual shakeout and sand conditioning produced m ean dust levels under 7 mppcf. Cleaning room operations showed m ean dust levels under 7 m ppcf except at portable grinding and chip ping w hich h ad a m ean d u st level of a b o u t 15 m ppcf. O th er m iscel laneous operations showed dust levels under 4 m ppcf with the exception of chipping-out of cupolas and sand unloading. T he high dust exposures a t the last two activities were interm ittent and of relatively short duration. Concentrations of aldehydes were of a low order of m agnitude. Carbon monoxide concentrations were relatively low in m ost instances, but high levels occurred for short periods at pouring operations during the winter months. In general, the foundries studied were clean; housekeeping was ade quate; and dust suppression m easures were employed. M any of the foundry buildings were well constructed according to m odern architec tural designs which perm itted adequate natural ventilation and natural illumination. Although the m ajority of the foundries were not com pletely mechanized, m odern production techniques were usually em ployed. M any of the foundries did not utilize the latest methods of artificial illumination. T he foundries studied gave no consideration to the reduc tion of noise. In general, sanitation facilities provided for em ployees were ade quate and m aintained in a satisfactory condition. Some im provem ents were needed in a few plants. 54 MEDICAL STUDIES Review of the Literature Studies of the health of ferrous foundry workers have generally centered on the diseases of the respiratory tract, and, more especially, on the effect of the dust of the occupation on the lung parenchym a ( 16, 17, 3 1 -5 8 ). T here have been a few studies on the general health of these workers, the m ost notable exam ples being those of Collis (59) and M acklin and M iddleton (42) in G reat Britain; but, these also discuss chiefly the lung diseases. Since the bulk of the literature on the health of the ferrous foundry workers refers to lung changes, these will be discussed at this time. It m ight be expected th at com parison of the chest findings in the present study could be m ade with the other reports. T he previous reports served well the purposes for which they were intended. H ow ever, for reasons which will soon be apparent, for only a lim ited num ber m ay com parisons of incidence rates of pulm onary fibrosis be m ade w ith th e p resen t report. T ab le 14 shows th e findings in regard to p u l m onary fibrosis as reported in these previous foundry studies in which such inform ation was recorded. It was with a great deal of trepidation th a t this table was prepared, since in m any instances appreciable license was necessarily taken in interpreting the data in those pub lished reports. I t will be n o ted from tab le 14 th a t a gross separation is m ade betw een th e first 12 rep o rts an d th e la tte r nine. A m ong th e reasons for this separation, noted in italics in the table, a re : (1 ) Selec tion for exam ination of workers of certain occupations only, as in studies 13, 15, 16, a n d 17; ( 2 ) selection for ex am ination of w orkers who had the longest periods of exposure in the industry, as in studies 17 and 18; (3 ) exam ination did not include a roentgenograph, as in studies 13 a n d 21; ( 4 ) use of ro entg en o g rap h y w as lim ited to certain w orkers, as in stu d y 19; ( 5 ) size of th e sam ple w as v ery sm all, as in studies 14 an d 15; a n d ( 6 ) th e ty p e of fo u n d ry stu d ied w as n o t sta ted in the published report, as in study 20. It is pointed out that, although th e d ata from the reports listed in th e u p p er portion of tab le 14 resem ble th e present stu d y in m any respects, both in m ethods used as well as criteria for diagnosis of degree of observed pulm onary fibrosis, even in these there appear dif ferences from the study now being reported. Again, these differences are, in each instance, indicated in the table by italics. It is well, there- $5 T able 14.-- D ata selected from previous Year Study of No. report Investigators 1 1935 Warfield ( 3 1 ) Country of study IT. S. (Wisconsin) Type of foundry -- -------- -- Ferrous Nonferrous Iron Steel Occupational groups studied Number of workers studied Yes N o No All ________ 691 2 1937 Osmond (3 2 ) U. S. (Pennsylvania) Yes Yes. No ,,do - - 686 3 1937 Kelly and Hall (3 3 ) U. S. (New York) . (*) (*) (*) 4 1938 Sander ( 3 4 ) ___ U. S. (Wisconsin) Yes Yes. No do _ do - 403 4,035 5 - - - - 1938 Trice and Easom IT. S. (North Carolina). Yes.. Yes.. Y e s ._ 8 foundries -- all; 16 546 (17). foundries-- se le c te d workers with 20 years or more exposure. 6 . . . 1938 7___ 1939 Greenburg, Siegal, and Smith ( 3 5 ). Sander (3 6 ) __ . U. S. (New York) U. S. (Wisconsin) Yes Yes Y e s All Yes Yes . Y e s do _______ 4,066 _ _ _ 8,377 8 ___ 1942 Brown and Klein U. S. (Washington, N o (37). D. C.). 9___ 1943 Feil ( 3 8 ) _____ France Yes 10___ 1945 Keatinge and Pot- Great Britain Yes ter (89). 11. . 1945 Riley, Butler, and U. S. (Washington, N o Goren (40). D. C.). Yes Y e s Yes. No N o . No Yes Fes do _ __ 454 do - -- 119 do _ - ____ 60 do ,, * 842 12___ 1946 Velicogna ( 4 0 ___ Italy. . . . (*) (*) (*) .do _ 120 13----- 1923 Macklin and Mid- Great Britain. . dleton (4 2 ). 14___ 1931 Komissaruk ( 4 3 ) _ _ Austria .. . . Yes. _ _ Yes Yes.. No . No. . No Casting cleaners (some degree of selection used). All ____________ 1,153 40 15___ 1932 Landau ( 4 4 ) - - Germany.. . . . . . (*) Yes No C a s t i n g c l e a n e r s ____ _ 39 16___ 1933 Landau ( 4 5 ) ___ . Germany _____ ____ Yes Yes No. C a s t in g c le a n e r s ____ _ 126 17___ 1934 Gudjonsson ( 4 6 ) . - - Denmark.. ____ ___ (*) (*) (*) C a s t in g c le a n e r s ______ 186 See footnotes at end of table. 56 studies of silicosis among foundry workers1 Classification of pulmonary fibrosis Percent of workers with pulmonary fibrosis Nodular Diffuse Nodular Diffuse Total Stage 1 2 3 Remarks N o_____ Y e s _____ Yes - Yes . . 15 1 Yes___ Yes____ 7.5 No_____ Y e s ____ Yes Yes _ 8 2 Yes Yes 4 5 Yes - Yes _. 21 0 Yes Yes - -- 1 1 . 2 Yes . Yes _ 5 9 Y e s ___ Yes 22 0 Yes Yes . Yes Yes 3 3 No_____ P r o b a b l y See rea d v a n c e d . marks. No_____ Y e s . _ No_____ Fes . . . Yes . . . Yes _ _ 19.0 Yes __ Yes_____ 8 . 6 17.5 8.9 8 . 2 10 1 1.2 1.2 0 7 0 6.3 0.7 1.5 1.5 0 2 7 2 . 2 0.4 5.8 2 4 2.2 0.2 5 9 0 0 0 2.1 1 . 8 0 . 2 5 0 47.0 30.0 51.3 69.1 36.5 25.5 18.7 13.9 3.2 0.4 The hazardous occupations, in descending order, were sandblasters, molders, chippers, laborers, crane men, coremakers. Roentgenograms oidy. Stereoroentgenograms used. After 20 years of expo sure found 44 percent silicosis. The hazardous occupations, in descending order, were steel chir pers, iron chippers, molders, coremakers, cranemen. 0 Surveyed 3 foundries. Physical examination and roentgenograms used. 0 Casting cleaning produced highest incidence, 28 per cent. Steel foundry produced more silicosis than iron foundry. The average exposure time required to develop silicosis was 25 years. The hazardous occupations, in descending order, were sandblast ers, chippers and grinders, molders, coremakers. 0 Twenty-four foundries studied. Physical examina tions and roentgenograms used. S te r e o r o e n tg e n o grams for those with 20 years' average exposure. The high incidence in molders was believed due to their longer employment. 0 . 1 Eighty foundries studied. R o e n t g e n o g r a m o n l y u s e d . Chippers had highest rate. Seventy-five foundries surveyed. This was an ex tension of study reported in 1938 by same author (3 4 ) and including the original 4,035 foundrymen studied ( 6 0 ). Greater incidence observed in steel foundries. 0 Physical examinations and 14 x 17-inch roentgeno grams used. Roentgenograms used. Casting cleaners had highest rate. 0 Physical examination and roentgenograms used. The most hazardous occupation was casting cleaning. 0 . 1 Same foundry reported by Brown and Klein in 1942 (37). Probably included diffuse fibrosis with stage 1 nodular. Roentgenographed on 4 % 5-inch stereo film s; 14 x 17-inch film s used for confirm ation only. Physical examination and roentgenograms used. Separate group of sandblasters described. Of 27 sandblasters, found silicosis in 55 percent;_______ No roentgenographic examination made. O v e r 5 5 p e r cent worked with sandstone grinding wheels. Roentgenograms used. Small foundry. Noted rapidly progressing tuberculosis as the cause of death. All cases were disabled and ill for some time. Roentgenograms used. 7.1 Rate very much higher in steel than iron. Stage 3 silicosis observed. 1 . 6 Roentgenograms used. D i d n o t i n c lu d e th o s e u n d e r 3 y e a r s ' e x p o s u r e . Found no tuberculosis. Cor recting for age and duration of exposure, found older workers more likely to develop silicosis. 57 T able 14.-- D ata selected fro m previous studies Year Study of No. report Investigators Type of foundry Country of study Ferrous Non ferrous Iron Steel Occupational groups studied Number of workers studied 18___ 1934 M cC onnell and U. S. (W isconsin).___ Yes Yes.. N o .. All (selected w o r k e r s ) _- 210 Fehnel ( 1 6 ). J9___ 1935 Kuroda ( 4 7 ) __ - J a p a n . . (*) Yes . No. A l l ________________ 314 2 0 ___ 1935 Pope and Zacks U. S. (Massachusetts).. (*) (*) (*) (48). ..do. . . 1,614 2 1 ___ 1948 Vigliani, Parmeg- Italy.. . . . giani, and Za netti (49). Yes.. Yes.. Fes.. All (includes steel fab 25,253 ricators'!. 1 Prepared by Senior Surgeon Harry Heim ann and Assistant Surgeon C. J. Buhrow. Note: Dashes (--) indicate that data are not available. T he use of italics is explained in the text on page 55. *T yp e of foundry was not stated. * * T h e 11.4 percent includes diffuse fibrosis. fore, in com paring the different reports noted, to consider the indicated variations. I t is further pointed out th at, in interpreting the recorded findings as to the occurrence of diffuse and nodular fibrosis, license was used in some instances. In general, however, it is felt th a t th e interpretations from the published reports were m ade without bias so th a t an approach m ight be m ade to a com parison w ith the data for the present study. W ith the above in mind, om itting from further consideration at this tim e studies n u m b ered 13 to 21, inclusive, th e following interesting facts m ay be noted from the table: (1 ) T he reported incidence of pulm onary fibrosis am ong foundry w orkers varied from 2.1 to 26.8 percent; (2 ) w hereas diffuse pulm onary fibrosis (defined in a later section) varied in incidence from 3.3 percen t to 22 percent of the workers, nodular silicosis was variously reported as ranging from zero to 17.5 p ercen t (in m ost of th ese rep o rts of th e n o d u lar ty p e th e disease was lim ited to nodular stage one or two, a few instances of stage three or conglom erate silicosis being reported in this industry by rela tiv ely few observers, as in rep o rts 1, 6, an d 1 1 ); ( 3 ) steel foundry work was reportedly m ore likely to cause silicosis than was iron foundry work, and casting cleaners were the m ost frequently affected; and (4 ) it generally required about 20 years to develop nodular silicosis in the foundry industry. 58 o f silicosis am ong fo u n d ry w orkers1-- continued Classification of pulmonary fibrosis Percent of workers with pulmonary fibrosis Nodular Diffuse Nodular Diffuse Total Stage 1 2 3 Remarks Yes____ Yes.. __ 13.3 31.4 30.0 1.4 0 8.0 Yes _ . **U 4 Yes_____ Yes.. 1.5 0.75 0 Roentgenograms used. Selected cases in order to show seriousness o f condition. Included five workers of non ferrous foundry. Of 715 examined, only 3I f roentgenographed; probably selected. The average exposure time to develop silicosis was 18 years. Steel casting cleaners had 6 . 6 percent silicosis. Seventy-five percent of workers examined on volun tary basis. Physical examinations and roentgenograms used. Surveyed 10 foundries. Fluoroscopic examinations of chest made. Steel foundries were worst with incidence of 5 percent of both diffuse and nodular fibrosis. Authors' note: An im portant new work, "Industrial Lung D iseases of Iron and Steel Foundry W orkers," by A. I. G. M cLaughlin and coworkers, H. M . Stationery Office, London, 1950, appeared after com pilation of the above table. Methods of Study For the year 1947, the latest year for which pertinent inform ation was available, there w ere 1,936 independent ferrous foundries in the U nited States, em ploying a total of 239,272 workers (1 ). (See also table 1.) T hese foundries, together w ith all captive foundries, em ployed ap p ro x im ately 341,000 production w orkers. In th e 16 foundries w ith w hich th e p resen t rep o rt is concerned, the to tal em ploym ent was a little over 2,000, of w hom 1,937, all males, w ere m edically studied. PERSONNEL AND FA CILITIES U tilized in the study was a total of nine physicians, two or three of w hom w ere in th e field a t a n y one tim e. I t was th e phy sician 's d u ty to obtain the occupational and medical history, to m ake the medical examination, and to supervise the work of the m edical technicians. T h e m edical tech n ician 's responsibility w as to m ake th e necessary chest roentgenogram and to study the urine and blood of the worker. Specialists in derm atology assisted in one phase of the study in evaluating the health hazards to the skin. Tw o dentists, one of whom was in the field at any one time, were p art of the m edical study team ; it was their function to evaluate the m anifestations of disease which m ight appear in the m outh of the worker. 59 Thus, a m edical team in the field consisted of two or three physicans, one dentist, and one m edical technician. T he field team was enlarged by the addition of an extra physician or technician when it was desired to com plete the work especially rapidly at a plant. T he team perform ed its work at the plant sites by using a suitably equipped house-trailer and a special dental exam ination truck. T he m edical trailer, m easuring approxim ately 8 by 28 feet, was partitioned into two medical exam ination rooms and a clinical laboratory. One of the medical examination rooms contained the roentgen ray equipment. The dental truck was constructed to house the usual dental examination equipm ent, including a dental roentgen unit. B oth the medical trailer and dental truck were moved from plant to plant as needed. Although both of these units were the basic facilities used for the m edical studies, from tim e to tim e a suitable room was provided by plant m anagem ent to supplem ent these facilities. In such instances, the extra space was used as the clinical laboratory. T he medical team and equipm ent arrived at each plant at a tim e prearranged by conference betw een officials of the Illinois D ep art m ent of Public H ealth and the plant managem ent. T he trailer and truck were placed at a convenient location in the foundry yard, and connections were m ade with electric current and water. The team was then ready to begin its examinations. T he foundry workers were notified through their labor organizations th at all exam inations were to be on a voluntary basis. M anagem ent cooperated to the fullest extent, providing suitable persons to assist in the assignm ent of the workers for the medical examinations. The tim e taken for each exam ination varied from 25 to 40 minutes, with an average of about 30 minutes. M en from all shifts were studied. TH E M EDICAL EXAM INATION F igure 13 shows th e d en tal form used, an d figure 14 th e m edical form, each indicating the extent of the exam ination made. A m anual of instructions for use of the forms was provided each person of the study team. The com plete form, including occupational history, was filled in by the examining physician. T he oral exam ination form was filled in by the dentist. The laboratory data were recorded as each test was completed. D ata from the chest roentgenograms were re corded later. Following the com pletion of the exam ination by the physician, the worker was ushered to the roentgen ray unit, where a picture was m ade of his chest. All roentgen ray exposures w ere m ade on 14 by 17-inch films for a half of a second at 72-inch target distance, using appropriate voltage and am perage dependent upon the anterior posterior diam eter of the chest. One exposure at deep inspiration was 60 (MGHT ORAL EXAMINATION Date Case No. Name C o lo r f e x Age 2 sn an aa aa aa aaaa,aa aa aa a aa as aa sa aa = 17 is 4 5 19 20 21 22 7^ 24 10 it 12 14 1 25 26 27 28 29 30 16 32 - Remarks C alcu lu s 0 12 3 4 LIPS Inflam m ation F issu re K eratosis Other C onditions Type of C alculus 12 3 Normal Abnormal LG 1 2 3 LG 12 3 4 GINGIVAE RIDGES G ingivitis C olor Change T issue Tonus K eratosis O ther C onditions Normal Abnormal LG 1 2 3 LG 1 2 3 4 P e ric la sia 0 12 3 4 Enamel GLANDS Normal Other Conditions Abnormal TONGUE Normal F issu re K eratosis LG V aricosity Other C onditions Abnormal 1 2 34 MANDIBIE Normal E x o sto sis Other C onditions Abnormal ORAL MUCOSA Inflam m ation K eratosis Other Conditions Normal Abnormal LG 1 2 3 LG 1 2 3 4 PALATE Inflam m ation K eratosis E x o sto sis Other C onditions Normal Abnormal LG 1 2 3 LG 1 2 3 4 VELUM Normal Abnormal Inflam m ation LG 1 2 3 O ther C onditions UVULA Normal Abnormal Inflam m ation LG 1 2 3 Other Conditions NEOPLASM P resen t Absent TEETH AND SUPPORTING STRUCTURES No. o f T eeth No. o f T eeth No. o f T eeth No. o f T eeth B rid g es D entures M issing Replaced C ario u s R e sto re d DENTAL NEED No. o f T eeth R eq u irin g F i l l i n g No. o f E x tr a c tio n s I n d ic a te d No, o f B rid g e s I n d ic a te d P a r t i a l D en tu res Upper Lower F u ll D en tu res Upper Lower P ro p h y la x is F igure 13.-- O ral ex am ination form (m o d ified ). m ade for each worker. Some difficulty in the roentgenography was occasioned by the fact th at the source of electric current was not con stant because of the starting or stopping of electrical equipm ent within the plants. Some pictures were thus lost and this fact, am ong others, accounts for the discrepancy between the num ber of medical exam ina tions m ade and th e num ber of chest films recorded, as observed in tab le 15. In general, th e roentgenogram s th a t w ere in terp reted were of good quality. For technical reasons it was considered advisable to develop all the films at the Public H ealth Service laboratories in W ashington. Following this, the films were interpreted by two physicians, working independently of each other. W here differences in interpretation existed, the two readers conferred for a decision. In all instances, the 61 USPHS FOUNDRY STUDY MEDICAL RECORD (condensed) (Page 1) No. : Establishm ent: GENERAL; Name ___________________________ A ddress____________________________________________ Age D ate___________ B ir th p la c e _________________________ Age began Trie,____ M S W D Sep. Sex: M F Race: W Nw Tim e:___________ Hours on s h i f t _____ ; sin c e food______ P re s , s h i f t : From_______ to ________ . Wkly h r s .: U sual_______ Max,______ Fam ily p h y s ic ia n ____________________________________________ OCCUPATIONAL HISTORY Specific job Pres. Frev. Department or in d u stry Time Foundry O ther (y rs.) (y rs.) Remarks T o ta l Chron. d i s , i n fa m ily : T b c,_____ S i l i c o s i s _____ O ther HABITS: ( E n c ir c le p o s i t i v e ite m s ) A lcohol: B W L Tobacco: C ts , C grs, P, Ch. Sn. D ru g s:_____ _________ Hours s l e e p :___ _B a th s :________ PREVIOUS ILLNESSES, Pneum. Tbc. Bronch, P le u r. Asthma Summary INJURIES, OR OPERATIONS: Sin. in fec. H rt. d is. Skin d is . Rheum. Colds p a st y r. H e rn i8 _______ Oper. & I n j. V. D. _____ " Other (Spec.) SYMPTOMATOLOGY: GENERAL: Weak_______ Mal.______ Drowsy_______ A lle rg y __________ Nervous_________________ EYES: P ain_____ D is c h ._ ____T e a r,_______ Photophobia____________ V is . d i s t . _______________ EARS: H e a r._ ____ T in n ._____ D is c h .________ P a in ________ O ther____________________________ NEURO-M,: V e r t ,____ P a r e s t . ______ HA_______ Insom .________ I r r i t a b , ______________________ Muse, weak. Muse, p a in ____________ J n t . p a in ______________________________ CAEBTO-RESP.: P a lp . _____ D y sp ._________ Edema___________ __ S yn._____________________ C hest p a in ___________ H o a rse _ ____________ Cough____________ E xpec,__________ Hemopt.__________ C. Cold_____ ______ E p i s t . ___________________________________ GI: Abd, p a in ________ N o r V _ _________ A nor.______ D ia r ,_________ C o n st,_______________ GU: D y su ria __________ Hemat,____________ N o c t.______ F r e q ._________ D is c h ._______________ SKIN: _______ ___________________________________________________________________________ OTHER AND REMARKS:_____________________________________________________________________________ F igure 14 (fro n t).-- M edical ex am ination form (co n d en sed ). films were interpreted w ith the m edical records available, b u t these records were only referred to when necessary for proper interpretation of the more obscure cases. Follow ing th e taking of the chest film, the m edical technician m ade exam inations of the blood and urine. The worker was asked to void his urine into a suitable container, in the presence of the technician. The urine was studied for the presence of album in by the heat and acetic acid te st an d for th e presence of glucose b y B en ed ict's q u a lita tive solution. M icrosopic review of the centrifuged urinary sedim ent was m ade of those specimens showing albumin. O btaining 10 cubic centim eters of blood by p u ncture of th e a n te cubital vein, the technician placed about 5 cubic centim eters into a test tube for the serological test for syphilis and the rem aining 5 cubic centim eters into a tube containing 6 milligrams of am m onium oxalate 62 MEDICAL RECORD (cond en sed ) (Page 2)' PHYSICAL EXAMINATION: APPEARANCE: Development G P N u tritio n G P P allor Jaundice C y an o sis H t._____ W t._____ P u lse ' Resp. r a t e _______ Temp.______ EYES: D ist. v is. - A ssisted: R 20/ L 20/ Pupils - Irreg u lar Unequal F ail to react to lig h t F a il to re a c t to accom. Lids - C onjunctiva and sc le ra - Cornea C ataract - Exophthalmos - Strabism us CHEST AND LUNGS: C hest - Assyra. F l a t B a r r e l Funnel Pigeon Grooved Spine - S c o lio sis R L Kyph. Lordo. In s p e c tio n ______________________ P alp a tio n _______________________ P e rc u s s io n ______________________ A u s c u lta tio n ____________________ CARDIOVASCULAR: Apex b e a t - P alp ab le O utside m idclav. lin e In te rsp a c e H e a rt sounds - A2 ^ = ^ .^ 2 Murmur - S y s t. D i a s t . P r e s y s t . a p ic . Rhythm i r r e g u l a r basal Blood p re ssu re - / POSITIVE FINDINGS: __________________ EARS: External ear Purulent disch. Drums Hearing - NOSE: Marked o b s tru c tio n Enlarged tu rb in a te s Septum d e v ia tio n P e rfo ra tio n of septum THROAT: T onsils - Absent P resent Infected 1 2 3 Pharynx - Inflam ed 1 2 3 U lceration NECK: EXTREMITIES: S k eletal A bnorm alities Hands and n a ils - Reflexes P a te lla r : I n c r , D eer. Abs. Ankle: I n c r . D eer. Abs. Peripheral vessels: Beaded S c le ro tic Tortuous G ait - Adenopathy C ervical axillary SKIN: X-RAY INTERPRETATION: Film co n d itio n - G F P Lung f i e l d m arkings - L in ear 1 2 GG 12 Nod. 1 2 Conglom. LABORATORY FINDINGS: Srodiagnostic te s t _______ BLOOD (S p ecify name) Sed. r a t e ___________ Heraato._ RBC______ VC______ Hb.______ Emphysema - 1 2 3 C a lc ific a tio n - H ilar Parenchymal Heart or aorta enlarged - 1 2 3 Diaphragm - Adhesions O b lit. Angles Othe r __________________________________ URINE: A ppearance______________________ Sp. g r . _________________________ Album.__________________________ G ly co . M icroscopic - RBC / hpf W3C______ /h p f C asts_____ /h p f VITAL CAPACITY: F ig u re 14 S ig n a tu re (back).-- M edical examination form (condensed). and 4 milligrams of potassium oxalate as the dry anticoagulant for the other studies (61, 62). Blood sm ears were m ade of the fresh blood. All the serological tests for syphilis were m ade by the Illinois D epartm ent of Public Health. T he K ahn test was done routinely and confirmed as necessary by other tests. T he blood smears were stained w ith W rig h t's stain for la te r study. T h e ery th ro cy te an d leucocyte counts were m ade by standard methods, and the hemoglobin estim a tions were done by the use of the H aden-H ausser hem oglobinometer (63). The blood sedim entation rate, later corrected for hem atocrit 63 determ inations, was m ade by using W introbe tubes (62), w ith read ings taken at the end of one hour. T he blood contained in the sam e W introbe tube was then centrifuged for 30 m inutes at 2,500 revolu tions per minute, and the hem atocrit reading recorded. T he W introbe indexes (6 2 )-- the m ean corpuscular volume, the m ean corpuscular hemoglobin, and the m ean corpuscular hem oglobin concentration-- were calculated from the erythrocyte count, the hemoglobin estimation, and the hem atocrit by using a suitable nomogram. T he vital capacity reading was then made, allowing the worker to m ake three tests. The highest of the three was recorded as the vital capacity. A standard w ater replacem ent type of spirom eter was used for this purpose. After being processed by the technician, the foundrym en were exam ined by a dentist. W ith the aid of a good source of light, exam i nations were m ade of the teeth as well as the other structures in the oral cavity. Bite-wing roentgenographic exposures were m ade of a representative num ber of the workmen. T able 15.-- M ajor m edical studies m ade of m ale workers in 16 ferrous foundries in Illinois Study- Number of workers Physical examinations____________ Chest roentgenograms____________ Oral examinations________________ Visual acuity____________________ Vital capacity___________________ Urine___________________________ Blood: Erythrocyte counts__________ Leucocyte counts____________ Hemoglobin estimations______ Hematocrit determinations____ Erythrocyte sedimentation rates Kalin tests__________________ 1,937 1,824 1,903 1,742 1,864 1 ,655 591 1,529 1,528 1.921 1.921 1,894 T he m ajor medical studies and the num ber of workers associated w ith each are show n in tab le 15. W ith th e exception of th e ery th ro cy te counts, all exam inations were made routinely on each worker who presented himself. T he erythrocyte counts were not begun until exam i nations were made at the eleventh plant. Except for the erythrocyte counts, the variation in num ber of the different types of exam inations is due in p art to th e inadvertent omission of certain tests or the refusal of workers to take them -- difficulties usually attendant at such studies. As indicated previously, th e 16 ferrous foundries studied em ployed about 2,000 persons, of whom 1,937 were m edically studied. 64 Results of Medical Studies Each m edical record was reviewed, interpretations of the data were m ade as necessary, and, finally, the m aterial was analyzed. M edical findings were correlated w ith each other, and certain m edical findings were correlated with environm ental data when it appeared th at these procedures would be useful. CHARACTERISTICS OF EX AM IN ED W ORKERS Socio-economic influences are known to be of significance in health and disease. Thus, the place of birth, race, age, sex, m arital status, personal habits, hours of work, tim e in foundry work, and occupation were analyzed. Birthplace Of the workers questioned, and for whom this inform ation was recorded, 980, or 51 percent, w ere born in th e S tate of Illinois or in the im m ediately adjacent states. T he rem aining 49 percent were born in states distant from Illinois or in foreign countries. Of the distant states represented, the nonwhite population weighted the data toward the southern part of the country. T he 498 foundrym en who were foreign-born were predom inantly from southern and eastern Europe. W hen the individual plants were considered for the num ber of persons born in foreign lands, the rate was found to vary m arkedly, ranging from 8 percent to 70 percent. Race Of th e 1,937 m edical exam inations m ade, 1,341, or 69 percent, were of white persons, and 31 percent were of nonwhite, all Negroes. T he percentage of workers of the different races that m ight be em ployed in foundries in the U nited States will be found to vary w ith m any factors, am ong w hich is the section of the country. F or exam ple, in a study of 4,066 foundrym en m ade in New Y ork State (35), nonw hite w orkers constituted 4.4 percent of th e total. Age T ab le 16 shows the age distribution of the foundry population studied. T h e m edian age was 40.7 years, w hich is sim ilar to th a t observed for open-hearth steelworkers recently studied by the Public H ealth Service ( 64). I t is to be noted that, w hereas the nonw hite workers show a m axim um frequency at the 25 to 29-year age group, the white population shows two maxim um s at age groups 30 to 34 and 55 to 59 years. T his has been observed in other studies m ade by the Public H ealth Service in the past. W ide variation of age grouping was observed from plant to plant. Com pared with industrial 65 T able 16.-- A ge distribution of exam ined m ale workers in 16 ferrous foundries in Illinois, according to race Age (years) Number Percent Total White Non white Total White Nonwhite T o tal________ Under 20 _ 20-24______________ 25-29______________ 30-34______________ 35-39______________ 40-44______________ 45-49______________ 50-54______________ 55-59______________ 60-64______________ 65 or over _ _ 1,937 45 171 208 270 246 201 172 189 191 165 79 1,341 31 84 112 176 153 130 112 146 169 154 74 596 100.0 100.0 14 2.3 2.3 87 8.8 6.3 96 10.7 8.4 94 13.9 13.1 93 12.7 11.4 71 10.4 9.7 60 8.9 8.3 43 9.8 10.9 22 9.9 12.6 11 8.5 11.5 5 4.1 5.5 100.0 2.4 14.6 16.1 15.8 15.6 11.9 10.1 7.2 3.7 1.8 .8 workers in the U nited States as a whole (65), the foundry workers of this study as a group ranked about five years older. Sex Although the present study lim ited its exam inations to males, it is not to be inferred th a t wom en are not em ployed in the ferrous foundry industry. F or the m onth of Septem ber 1949, for example, approxim ately five percent of the w orkers in the ferrous foundries of the United States were women (66). M arital Status E ig h ty p ercen t of th e w orkers w ere m arried; 14 percent, single; and the rem ainder, widowed, separated or divorced. This was sim ilar to other industrial groups recently studied by the Public H ealth Service. Personal Habits I t is of som e in terest th a t on th e subject for w hich greatest inac cu racy m ight b e expected-- th a t is, im bibition of alcoholic beverages-- the data obtained followed very closely those recorded by other exam iners of the Public H ealth Service for a com parable industrial group ( 6 4 ) . In th e p resen t study, 17 p erce n t d enied th e use of alco holic beverages; 33 percent adm itted the use of only beer and wine; 50 percent said they drank beer, wine, and stronger spirits. T he degree to which they indulged in these beverages was not determ ined. Although the use of alcoholic beverages varied from plant to plant, 66 a positive association was found betw een the percentage of foreignborn workers in a plant and the taking of alcohol in any form, gen erally as wine. Eighty-five percent of the w orkers said th a t th ey used tobacco in some form. Of these, 80 percent smoked, and the other 5 percent used snuff or chewed tobacco. T he older age groups did less smoking and more chewing or snuffing of tobacco. These data conform to our find ings in sim ilar occupational groups which we have studied. H ours spent in sleep were recorded as eight or nine by 68 percent of the foundrym en. A few spent only 5 hours in sleep, while 5 percent slept 10 hours each day. T h e longer hours of sleep occurred m ore commonly among the older foundrymen. Fifty-three percent of the workers said that they took daily baths. This was appreciably higher than in two other cleaner industries that we recently studied. Hours of W ork In a consideration of disease states, such as silicosis, due to long industrial exposure, it would be expected th at the tim e spent in a given industrial environm ent would be directly related to the disease condition which m ight be created by th at environm ent. Thus, not only is th e num ber of years spent in the in d u stry of consequence, b u t the weekly num ber of hours spent on the job m ay also be im portant. T he num ber of hours of work per week spent in the occupation by most of the persons in the present study group was 40. Since the num ber of hours per week spent in foundry work during the war years (1940-45) m ight have been sufficiently different to have caused certain abnorm alities in our findings, the w artim e experi ence was also considered in the study. Inform ation available indicated that, during those years, ferrous foundrym en worked an average of 48 hours per week. T he difference betw een the peacetim e hours and the w artim e hours is a factor of 20 percent. Thus, th e 5-year war period, when converted for present purposes into peacetim e years, would constitute six years of exposure, a difference of only one year. This appears to be of doubtful significance in the present study in view of the m any years of exposure necessary to produce pulm onary fibrosis in this industry. Years in Foundry W ork T h e significant factor of years w orked in ferrous foundries is shown in tab le 17. I t is felt th a t an a d e q u ate sam ple; from th is p o in t of view, is rep resen ted in th e stu d y group, since 12.5 p ercen t h ad spent 30 years or m ore in foundry work; 24.8 percent, 20 years or more; and 45.1 per cent, 10 years or more. As m ight be expected, close correlation was found betw een increasing age and years spent in foundry work. It was 67 T able 17.-- D istribution of years in ferrous foundries of exam ined m ale workers in 16 foundries in Illinois, according to race Years in ferrous foundries Number Percent Total White Nonwhite Total White Non white1 T o tal________ 11,937 11,341 596 Less than 5 690 330 360 5 - 9 _________ __ 373 259 114 10-14_____________ _ 240 193 47 15-19______________ 153 122 31 20-24______________ 139 119 20 2 5 - 2 9 ______________ 99 84 15 30-34______________ 92 86 6 35-39______________ 70 68 2 40-44______________ 46 45 1 45 or over 34 34 0 1 One with years in ferrous foundries not stated. 100.0 35.6 19.3 12.4 7.9 7.2 5.1 4.7 3.6 2 .4 1.8 100.0 24.6 19.3 14.4 9.1 8.9 6.3 6.4 5.1 3.4 2 .5 100.0 60.4 19.1 7.9 5.2 3.4 2.5 1.0 .3 2 0 observed th at the nonwhite workers on the average had spent fewer years in the industry than had the white. O ccupation Questioning the men about their occupations prior to foundry work elicited the following interesting facts. Tw enty-three percent of the m en had come to the foundry from work in agriculture, forestry, or fishing. A pproxim ately 4 percent cam e from trades w here there m ight have been excessive dust in the occupation. Of special im portance are considerations of the em ploym ent at the tim e of the exam ination and of the workers' previous occupations in foundries. These are the two factors which m ust be given prom inence in the correlations to be m ade with health status. S eparate consideration is given to present occupation and principal occupation. It will be at once apparent th at those disease conditions dependent for their developm ent on long periods of exposure might be correlated with principal occupation; whereas, those conditions dependent for their genesis on very recent occupational exposure should have only the present occupation considered. T he principal occupation represents the particular broad occupational group fol lowed for the greatest num ber of years while working in foundries. If the individual foundrym an worked at two or m ore occupations for the sam e num ber of years, the m ost recent is considered as the prin cipal one. Analysis was m ade of each medical history, and the principal occupation determined, the present occupation being easily observed from those records. 68 T ab le 18 shows th e division of the 1,937 m en into various detailed occupations. Since the gray iron and steel foundries differ somewhat in this regard, separation of the two is m ade in the table. Consideration of each of the job classifications separately in the correlations w ith the m edical findings would have resulted in such small num bers of workers as to m ake such correlations of doubtful value. For this reason the job classes were grouped into larger seg ments. This classification has the further advantage th at for each of four of the six categories the environm ental conditions are essen tially sim ilar for the job classes included under th at category. The six m ajor occupational groups are: corem aker, molder, cleaning and finishing, shakeout, m aintenance and supervisory, and laborer and other. T he latter two are the heterogeneous groups. T ab le s 19 a n d 20, using th e six o ccupational groups, show a dis tribution of the foundry workers by principal and present occupation, respectively. It will be observed from the tables th a t the percentage of workers in the various occupational groups does not differ much w hen com parison is m ade betw een present and principal occupations. There appears to be a tendency, noted for both races and for each of the age groups, for the present occupation to have fewer molders, cleaners and finishers, and m ore of the groups of m aintenance and supervisory workers and laborers. In further evaluating the relation ship of present to principal occupation of the individual foundryman, it was generally found th at in over 80 percent of instances the present and principal occupations were identical. M EDICAL FIN D IN G S Previous Illness Inquiry concerning certain previous illnesses revealed th at 20 per cent of those exam ined had had pneum onia (lobar or bronchial) or pleurisy, 4 p erce n t h ad chronic bronchitis, an d 1.5 p ercen t h ad h e a rt disease. In 13 p erce n t th e re existed one or m ore of th e follow ing chronic diseases of the cardiorespiratory system: bronchial asthma, heart disease, nasal sinusitis, and chronic bronchitis. Present Sym ptom s As in d icated in th e m edical exam ination form, figure 13, specific inquiry was m ade into a series of sym ptom s which the worker might have had at the tim e of the examination. It was noted that the workers adm itted most frequently to having sym ptom s of cough, dyspnea, and m uscular or joint pains. Some of this inform ation will be considered again w hen the dust effects on the lungs are discussed. 69 Table 18.-- N um ber of workers in detailed principal occupations of m ale workers in 16 ferrous foundries in Illinois according to type of foundry and race Gray iron foundries Steel foundries Principal occupation Total Race White Yonwhite Total Race White Non white Total 1,267 930 337 670 411 259 C oremaker _ . 149 141 8 95 73 22 M older _ 416 328 88 134 72 62 C leanin g and F in ish ing 180 126 54 162 101 61 Cleaning and finishing department workers, unspecified- . _ 25 18 7 33 20 13 Swing grinder _ _ . 3 2 1 34 24 10 Chipper and giindtr, ether than swing grinder _ _ _ 69 50 19 40 24 16 Sand blaster __ _ . 16 8 8 18 7 11 Tumbler operator _ 6 4 2 0 0 0 Burner _ __ __ 3 3 0 28 21 7 Stationary grinder 48 36 12 9 5 4 Other cleaning and finishing department workers __ _ _ 10 5 5 0 0 0 SHAKEOUT- _ . _ _ _ 161 69 92 65 15 50 Sand conditioning worker _ . 7 5 2 7 0 7 Sand mixer, h an d -. - 3 1 2 0 0 0 Sand mixer, machine _ _ 15 12 3 11 5 6 Shakeout _____ . _ _ _ 136 51 85 47 10 37 M a in ten ance and S uperviso r y.- _ _ 103 101 2 69 64 5 Maintenance men, unspecified. _ 16 16 0 19 17 2 Carpenter . 8 8 0 1 1 0 Electrician._ . _ . 0 0 0 5 5 0 Mechanic . . . . 1 1 0 3 3 0 Millwright _ _ _ 2 1 1 11 11 0 Office worker _ . 8 8 0 2 2 0 Shipping, receiving clerk __ . 12 12 0 5 3 2 Supervisory em p loyee___ _ _ __ 35 34 1 18 18 0 Guard, watchman _ 1 1 0 4 3 1 Pattern maker _ . 20 20 0 1 1 0 Laborer and Other . __ 258 165 93 145 86 59 Melter .. ______ 0 0 0 22 14 8 Cupola man _. . 67 41 26 1 1 0 Electric furnace operator .. 1 1 0 12 9 3 Reverberatory furnace operator _ 1 1 0 1 0 1 Annealer _ ... . 5 4 1 0 0 0 Pourer__ 38 11 27 8 1 7 Brickmason _ _ . 3 2 1 1 1 0 All other production workers. _ 13 10 3 18 16 2 Crane operator . . _ . 16 14 2 30 22 8 Sweeper, cleaner, jan itor.. Yardman, truck driver 6 4 2 4 2 2 27 20 7 4 4 0 Laborer __ . _. _. _ _ 81 57 24 44 16 28 70 T able 19.-- Principal occupation of m ale w orkers in 16 ferrous foundries in Illinois according to age and race for gray iron and steel foundries Number Percent Principal occupation Total Coremaker . _ _ _ Holder Cleaning and finishing Shakeout, Maintenance and supervisory. Laborer and other _ Total _ Coremaker Holder _ __ Cleaning and f i n i s h i n g . ___ S hak eou t___ _____ ____ __ Maintenance and supervisory. Laborer and other _____ __ _ White Nonwhite White Nonwhite Age Total Under 35 35-54 55 or over Age Total Under 35 35-54 Age 55 or over Total Under 35 35-54 55 or over Age Total Under 35 35-54 55 or over Gray iron foundries 930 298 353 279 337 171 144 141 50 57 34 8 3 3 328 77 127 124 88 38 44 126 40 45 41 54 26 27 '69 22 31 16 92 50 34 101 38 39 24 2 0 2 165 71 54 40 93 54 34 22 100 32.0 38.0 30.0 2 100 35.5 40.4 24.1 6 100 23.5 38.7 37.8 1 100 31.7 35.8 32.5 8 100 31 .9 4 4 . 9 2 3 . 2 0 100 37.6 38.6 23.8 5 100 43.0 32.8 24.2 100 50.7 42.8 100 37.5 37.5 100 43.2 50.0 100 4&1 50.0 100 54.3 37.0 100 0 100.0 100 58.1 36.5 6.5 25.0 6.8 1.9 8 7 0 5. 1 Steel foundries 411 105 188 118 259 120 123 73 23 38 12 22 10 10 72 22 24 26 62 25 32 101 20 52 29 61 20 38 15 2 7 6 50 26 22 64 16 33 15 5 3 1 86 22 34 30 59 36 20 16 100 25.6 45.7 28.7 2 100 ; 31.5 52.1 16.4 5 100 30.6 33.3 36.1 3 100 19.8 51.5 28.7 2 100 13.3 46.7 4 0.0 1 100 25.0 51.6 23.4 3 100 25.6 39.5 34.9 100 46.3 4 7 .5 100 45.5 4 5 .4 100 40.3 51.6 100 32.9 62.2 100 52.0 44.0 100 60.0 2 0 .0 100 61.0 33.9 6.2 9.1 8.1 4.9 4.0 20.0 5.1 to T a b le 20.-- P resent occupation of m a le w orkers in 16 ferrous foundries in Illinois according to age and race for gray iron and steel foundries Number Percent Present occupation Total . _ Coremaker _ ____ M o ld e r____ _ ____ Cleaning and finishing _ Shakeout- _ Maintenance and supervisory. Laborer and o t h e r ________ Total . Coremaker ______ Molder. _ ... Cleaning and finishing____ Shakeout. _ Maintenance and supervisory. Laborer and other White Nonwhite White Nonwhite Age (years) T otal Under 35 35-54 55 or over Total Age (years) Age (years) Under 35 35-54 55 or over Total Under 35 35-54 55 or over Age (years) Total Under 35 35-54 55 or over Gray iron foundries 930 298 353 279 337 171 144 149 56 59 34 8 3 3 310 76 120 114 76 34 38 108 35 38 35 58 27 30 69 20 30 19 88 48 31 123 38 49 36 3 1 2 171 73 57 41 104 58 40 22 100 32.0 38.0 30.0 2 100 37.6 39.6 22.8 4 100 24.5 38.7 36.8 1 100 32.4 35.2 32.4 9 100 28.9 43.5 27.6 0 100 30.9 39.8 29.3 6 100 42.7 33.3 24.0 100 50.8 42.7 100 37.5 37.5 100 44.7 50.0 100 46.6 51.7 100 54.6 35.2 100 33.3 66.7 100 55.8 38.4 6.5 25.0 5.3 1.7 10.2 0 5 .8 > Steel foundries ill 105 188 118 259 120 123 66 18 36 12 27 12 13 71 23 25 23 55 22 28 88 15 46 27 60 18 39 14 2 5 7 43 24 16 83 24 41 18 4 2 1 89 23 35 31 70 42 26 16 100 25.6 45.7 28.7 2 100 27.3 54.5 18.2 5 100 32.4 35.2 32.4 3 100 17.0 52.3 30.7 3 100 14.3 35.7 5 0 .0 1 100 28.9 49.4 21.7 2 100 25.9 39.3 3 4.8 100 46.3 47.5 100 44.4 48.2 100 4 0 .0 50.9 100 3 0 .0 6 5 .0 100 55.8 37.2 100 50.0 25.0 100 60.0 37.1 6.2 7.4 9.1 5.0 7.0 25.0 2.9 W eight Deviation T he foundrym en were weighed clad in their work clothes except their shirts. Calculation of the weight deviation for each worker from the average weight of insured men of similar age and height ( 67) yielded the distribution of percentage deviations reflected in table 21. T he table shows, furtherm ore, th at the percentage weight deviations of the present study group were distributed in a m anner sim ilar to those of the open-hearth steelmen, another industrial group studied by the Public H ealth Service (64). Table 21.-- D istribution of m ale workers in 16 ferrous foundries in Illinois by percent weight deviation from the average weight of m en of their height and age according to life insurance tables,1 com pared with open-hearth steelworkers Percent weight deviation from average Number Foundry workers Open-hearth steelworkers2 Percent Foundry workers Open-hearth steelworkers2 Total 25 to 34 below 15 to 24 below 5 to 14 below + 5 5 to 14 above 15 to 24 above 25 to 34 above 35 or more above .. Mean (percent). Standard devia- tion (percent). 1,678 7 131 409 479 337 183 83 49 + 2 .7 14.0 322 3 20 77 100 68 38 11 5 + 2 .2 13.3 100.0 .5 7.8 24.4 28.5 20.1 10.9 4.9 2.9 100.0 .9 6.2 23.9 31.1 21.1 11.8 3.4 1.6 1 Reference 67. 2 Reference 64. E ye Findings By the use of the Keystone Telebinocular (68), tests for acuity of d istan t vision w ere m ade of 1,742 foundrym en. All tests w ere m ade with the worker wearing the corrective spectacles he used at his work. This served the purpose of testing his occupational visual acuity. O ther than possible effects upon vision from infrared rays em anat ing from the hot m etal, seriously doubted by some observers (69), adverse effects on the eye m ight be found in this industry as a result of the dust floating in the air or the fast-moving particulate m atter throw n into the air by certain of the chipping, grinding, and polishing processes. To the extent th at exam ination was m ade for eye effects of 73 infrared rays, no significant abnorm alities were observed in this study. Particulate m atter in the air of the working environm ent m ay cause dam age to the conjunctiva and cornea and, less frequently, to the deeper eye structures. W hen such dam age occurs to the cornea, it m ay in some instances be painless but result in dystrophic changes (70-72). Study of the distribution of the visual acuity findings, divided according to the degree of dustiness of the industrial exposure in the principal occupation and according to the presence in the workroom air of high-speed particles involved in the operation concerned, ap p eared to show no differences. A lthough it is recognized th a t th e proper use of eye protective equipm ent will appreciably lower the incidence of eye injuries, no weight was given in this evaluation to the wearing of eye protective apparatus. T o test further the possibility that the degree of dustiness of the occupation m ay have caused dam age to the eyes, the incidence of certain eye sym ptom s and signs was correlated with the occupations of the foundrym en at the tim e of the examination. It was found that neither the sym ptom of photophobia nor the objective sign of con junctival congestion was significantly related to any of the six m ajor job categories, in spite of the fact that the dustiness of these job cate gories varied, as show n in tab le 9. Nose T he exam ination of the nasal cavity was m ade with the use of a good light and a nasal speculum. In m any w orkers accum ulations of the foundry dust were found at the nares and deeper inside the nasal cavity. In three instances the cartilaginous septum was found to be perforated. A review of the medical records of the three foundrym en so affected showed th a t one had had a subm ucous resection of the septal cartilage, which could have accounted for the condition. No apparent reason for the condition could be found in the other two workers, whose principal occupations were corem aker and casting cleaner, respectively. H ern ia D uring the examination, a check was also m ade for inguinal hernia * by observation and palpation of the scrotal sac as well as both inguinal canals, w ith the w orker in the standing position. Considering pre viously existent hernias as well as those brought to light at the tim e of th e exam ination, a ra te of 11 p ercen t w as found. N o relatio n sh ip was found between the presence of hernia and occupation. Inguinal hernia was present at the tim e of the physical examination in 2.3 percent of the workers. F o r a large series of iron and steel workers recently reported, the incidence of hernia on exam ination was 74 4.3 percent ( 7 3 ). T h e difference in the findings for th e two series of m en m ay possibly have been due to the differences in the exam iners and the criteria used in the two studies. Skin D erm atologists participated in the study to the extent of conferring with the regular examining physicians, reviewing the dermatologic data recorded on the m edical exam ination forms, and visiting the foundry in which an outbreak of derm atitis occurred. T he m edical records showed that, at the tim e of the examination, 251 foundrymen had some type of skin disease, which was m ost likely industrial in origin in 33 instances, or in 1.7 p ercen t of th e to ta l exam ined. T h e 33 cases w ere d istrib u ted as follows: occupational co n tact derm atitis, 12; h ea t rash, 18; an d o ccupational acne, 3. T h e cases w ere d istrib u ted in a random m anner through all of the occupational groups. In the course of the study one of the plants had an outbreak of contact derm atitis. T he cases all occurred among corem akers and were shown by patch tests to be caused probably by a phenol form aldehyde resin which was being newly used as the sand-binding material. W ith the institution of the custom ary protective measures, such as protective clothing, barrier creams, and personal cleanliness, new cases ceased to occur. It m ay be of interest to observe that, since the com pletion of the field studies of this investigation, other instances of derm atitis outbreaks among corem akers have come to the attention of the Public H ealth Service. In all cases, the occurrence of disease was halted by the adoption of protective measures Joint and M uscle Pains R eports of joint pains as well as m uscular aches and pains have been related to occupations involving exposure to high environm ental heat, as in the foundry industry, where the worker m ay be exposed to rapid changes of tem perature. Correlation of com plaints of muscle and joint pains with occupational group, both for principal and present occupation in which exposure to elevated tem peratures varied from group to group, failed to show th at any one group had these com plaints significantly more frequently than any other. Cardiovascular-renal Disease Blood pressure readings, m ade after a five to ten m inute rest period w ith the w orker seated, are shown in table 22, com pared w ith sim ilarly obtained data in the open-hearth steel industry (64). W hile the dif ference betw een th e blood pressures of th e tw o groups of w orkers is not spectacular, it m ay be noted that for each age group the blood pressures of the foundrym en. were consistently below those for the 75 open-hearth steelmen. Since there was an observed racial variation of blood pressure, the white workers having somewhat higher readings than the nonwhite, a test was m ade of the blood pressures of only the white foundrym en and the blood pressures of the white open-hearth steelm en. This, again, suggested th at in the present study group the blood pressures were slightly lower for all age groups. Table 22.-- M ean systolic and diastolic blood pressures of workers in 16 ferrous foundries in Illinois compared with open-hearth steelworkers, according to age m ale m ale Age (years) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Foundry workers Open-hearth steelworkers1 Foundry workers Open-hearth steelworkers1 T otal _ _ 129.4 132.7 81.1 84.0 Under 25 _...... . 118.5 121.7 73.5 77.3 25-29___________ 121.3 124.1 76.3 80.5 30-34__________ 124.4 126.0 79.4 81.7 35-39_______ 124.7 126.9 80.3 81.7 4C-14_____ 129.1 130.7 82.8 85.4 4 5 - 4 9 ___ 129.1 132.1 82.0 85.4 50-54_________ 134.6 138.8 84.3 85.9 55-59______ . 140.7 148.8 87.0 90.4 60 or over 144.1 147.3 85.7 85.5 1 Reference 64. Blood pressures of over 140 mm systolic or 90 mm diastolic, or both, w ere found in 240 foundrym en, or 13.2 percent. W h en th ese were distributed according to principal occupation and years in th at occupation, no association was evident. Study was m ade of those foundrym en whose blood pressures were recorded as either 160 mm systolic or higher or 100 mm diastolic or higher, or a t both of these elevated levels. As would be expected, the 201 foundrym en so affected were specially of the older age groups. W hen the data were corrected for age, it was found that the elevated blood pressures showed a positive association with increasing degrees of pulm onary fibrosis, the reason for which was not apparent. See table 23. It is of interest to note th a t there was a progressive increase in the incidence of elevated blood pressures as the hours at work increased. This refers especially to those exam inations m ade during the day shift and is in conform ity w ith the recognized diurnal blood pressure varia tion (74, 75). 76 Table 23.-- Roentgenographic pulm onary m arkings of the 201 males in 16 ferrous foundries in Illinois who had systolic blood pressure of 160 m m of m ercury or over and/or diastolic blood pressure of 100 m m of m ercury or over, according to age Age (years) Totali Roentgenographic pu ;in unary mar' i igs Normal and lineai one Linear two G round glass one Ground glass two Nodular Number with elevated blood pressure T otal______ 201 28 65 47 36 8 Under 40 . __ 24 4 11 6 2 0 40-59____________ 113 19 39 23 18 5 60 or over _ 64 5 15 18 16 3 Percent of all foundry workers Total . 10.4 5.1 8.9 12.5 25.7 Under 40 _ _... 2.6 1.1 2.9 4.4 10.5 40-59____________ 15.0 12.8 13.5 13.0 22.8 60 or over 26.2 14.3 23.1 29.0 38.1 28.6 0 27.8 30.0 1 Includes persons with roentgenographic pulmonary markings not stated. In addition to the blood pressure records, the medical study included, in the single exam ination of each worker, the following for evaluation of cardiac status: (1 ) M edical history; (2 ) medical examination, including palpation and auscultation of the heart; (3 ) blood K ahn serological test for syphilis; and (4 ) the chest roentgen ogram tak en a t 6-foot targ et distance. I t is recognized th a t to m ake a diagnosis of heart disease would require other pertinent data, such as an electrocardiogarm as well as study of the worker on more than one occasion. W ith the lim itations im posed by these facts, however, each clinical record was reviewed and an opinion recorded as to the presence or absence of heart disease; and, if heart disease were sus pected, record was m ade of its etiological diagnosis according to the criteria of the New York H eart Association (76). It was found that the data were, in general, sim ilar to the cardiac findings in other studies m ade by the Public H ealth Service in recent years. T he cardiac status in silicosis has been studied by m any investi gators (77 -8 9 ). However, this has centered about right-sided cardiac h y p e rtro p h y due to ad v an ced silicosis; th a t is, conglom erate silicosis. In the present study, only one case of this stage of the lung disease 77 was observed, and thus it would not be expected that cardiac complica tions would be prominent. T he studies m ade of the kidneys were lim ited to urine exam ina tions. A lbum inuria was present in 28 single specimens examined. T he exam ination of the urinary sediment, restricted to those urines having album in, show ed a significant nu m b er of ery th ro cy tes in 10 specim ens, excessive n u m b er of leucocytes in 6, an d hy alin e or finely g ran u lar casts in 8. T h e o ccupational d istrib u tio n of th e w orkers w ho m an i fested album inuria was a random one. Their age distribution was not rem arkable. As might be expected, it was found th at hypertension was associated with album inuria in some instances. Study of the records of these cases showed no unusual factors in either occupation or medical history. A t this point it is noted th a t the urine exam inations w ere positive for th e presence of glucose in 0.5 percent, or eight cases, an incidence which was sim ilar to th at of other studies of industrial groups recently m ade by the Public H ealth Service. Seven were for white persons and one for a nonwhite worker. Four were known diabetics who were under therapy for the disease. Blood Studies T he K ahn serological test for syphilis was done on all blood speci mens subm itted to the laboratories of the Illinois State D epartm ent of P ublic H ealth. Satisfactory tests were m ade for 1,894 of the foundrym en and w ere reported as positive for 87, or 4.6 percent. Classified by race, it w as found th a t 2.1 p ercent of th e single blood specim ens of th e w hite foundrym en gave positive K ah n tests, an d 10.3 p ercen t of th e nonw hite gave positive tests. T h is is in harm ony w ith other p u b lished reports. (9 0 ,9 1 ). T he erythrocyte counts of the foundrym en are shown in table 24 com pared with those of the open-hearth steelm en recently studied (64). It appears from this table th at the erythrocyte counts in the present study group were significantly lower than in the other group. On the other hand, the total leucocyte counts of the foundrymen com pared with those of the open-hearth steel workers, shown in table 25, were not significantly different. H em oglobin values are recorded in table 26, com pared w ith similar data for open-hearth steel workers. T he data indicate th at the hem o globin values for the foundrym en were significantly lower than those of the open-hearth steelmen. Correlations with occupation of erythrocyte counts, leucocyte counts, and hemoglobin estimations, respectively, showed no association. Since erythrocyte counts and hemoglobin estimations, respectively, 78 T a b le 24 ---E r y th r o c y te counts for m ale w orkers in 16 ferrous foundries in Illinois compared with male open-hearth steelworkers Erythrocyte count (millions per mm 3) Foundry workers Open-hearth steelworkers1 Foundry workers Open-hearth steelworkers1 Number Percent Total _ 591 Under 4.2 . ________ 50 4.2__________________ 15 4.3__________________ 24 4.4__________________ 32 4.5__________________ 26 4.6__________________ 48 4.7__________________ 42 4.8__________________ 61 4.9__________________ 60 5.0__________________ 74 5.1______________ 68 5.2__________________ 44 5.3__________________ 25 5.4__________________ 7 5.5 or over 15 1 Reference 64. 350 100.0 0 8.6 1 2.5 1 4.1 3 5.4 3 4.4 8 8.1 24 7.1 59 10.3 58 10.2 80 12.5 68 11.5 34 7.4 8 4.2 3 1.2 0 2.5 100.0 0 .3 .3 .9 .9 2.3 6.9 16.8 16.6 22.8 19.4 9.7 2.3 .8 0 Table 25.-- D istribution of total leucocyte counts for m ale workers in 16 ferrous foundries in Illinois compared w ith open-hearth steel workers Total leucocyte count per mm 3 Number Percent Foundry workers Open-hearth steelworkers1 Foundry workers Open-hearth steelworkers1 Total _ Less than 5,000 _ _ 5,000- 6,900________ 7,000- 8,900________ 9,000-10,900________ 11,000-12,900________ 13,000-14,900________ 15,000 or over . 1Reference 64. 1,529 23 295 513 371 212 91 24 350 100.0 1 1.5 66 19.4 134 33.5 86 24.3 55 13.8 7 5.9 1 1.6 100.0 .3 18.8 38.4 24.5 15.7 2.0 .3 79 Table 26.-- H em oglobin values for m ale workers in 16 ferrous foundries in Illinois compared with open-hearth steelworkers Hemoglobin (grams per 100 cc of blood) Foundry workers Open-hearth steelworkers1 Foundry workers Open-hearth steelworkers1 Number Percent Total __ Under 13 -....... .... 13__________________ 14________ . 15_ ___________ 16 . 17_______ 18__________________ 1,528 21 71 250 550 421 181 34 350 100.0 0 1.4 4 4.6 39 16.4 102 36.0 117 27.6 74 11.8 14 2.2 100.0 0 1.1 11.2 29.2 33.4 21.1 4.0 1 Reference 64. were found to be lower for the total foundry population studied when com pared w ith the open-hearth steelm en, and specific occupations in the foundry did not account for the difference, it would appear th at factors other than the industry were probably responsible for this situation. For example, geographic differences between the locations of the two groups and dietary influences m ay be responsible for the blood variations. Com parative data for hem atocrit levels were available for male shipyard workers (9 2 ) and are shown in table 27, together w ith hem a tocrit levels for the foundrymen. No significant differences are m anifest Table 27.-- H em atocrit readings for m ale workers in 16 ferrous foundries in Illinois compared w ith m ale shipyard workers Hematocrit reading (percentage of packed red blood cells) Number Foundry workers Shipyard workers1 Percent Foundry workers Shipyard workers1 Total Less than 37 . .. _ 37 and 38 . _ 39 and 40 _ 41 and 42 .. . 43 and 44 . 45 and 46 47 and 48 _ 49 and 50 _ 51 and 52 53 and 54. ... 55 or over. _ 1 Reference 92. 80 1,921 28 38 89 150 211 354 378 330 212 95 36 2,457 6 20 60 165 376 569 566 411 187 79 18 100.0 1.5 2.0 4.6 7.8 11.0 18.4 19.7 17.2 11.0 4.9 1.9 100.0 .3 .8 2.5 6.7 15.3 23.2 23.0 16.7 7.6 3.2 .7 betw een the two groups. Similar observations were m ade for cor rected erythrocyte sedim entation rates as shown in table 28. Table 28.-- Corrected sedim entation rates of erythrocytes for m ale workers in 16 ferrous foundries in Illinois compared w ith male shipyard workers Corrected sedimentation rate (mm in 1 hour) Number Foundry workers Shipyard workers1 Percent Foundry workers Shipyard workers1 Total _. Less than 10 10-14___________________ 15-19___________________ 2 0 - 2 4 ___________________ 25 or over 1Reference 92. 1,921 981 489 270 86 95 2,178 1,222 433 258 121 144 100.0 51.1 25.5 14.1 4.5 4.8 100.0 56.1 19.9 11.8 5.6 6.6 Various studies of occupational diseases have indicated significant or suggestive alterations from norm al of the m ean corpuscular volume, the m ean corpuscular hemoglobin, and the m ean corpuscular hem o globin concentration (93-96). Calculations of these indexes (62, 97, 98), m ade for the present study group, are shown in tables 29, 30, and 31. A com parable industrial group was not available to us. Table 29.-- M ean corpuscular volum e of blood of m ale workers in 16 ferrous foundries in Illinois, according to race Mean corpuscular volume (cu. microns) Total Race White Nonwhite Total Race White Nonwhite Number Percent Total 588 388 200 100.0 100.0 100.0 Less than 86 .. 38 27 11 6.5 6.9 5.5 8 6 - 8 9 __________ 48 32 16 8.2 8.3 8.0 9 0 - 9 3 __________ 82 52 30 13.9 13.4 15.0 9 4 - 9 7 __________ 114 81 33 19.4 20.9 16.5 98-101__________ 98 55 43 16.7 14.2 21.5 102-105__________ 89 54 35 15.1 13.9 17.5 106-109__________ 36 27 9 6.1 6.9 4.5 110-113__________ 44 34 10 7.5 8.7 5.0 114-117__________ 13 10 3 2.2 2.6 1.5 118-121__________ 14 8 6 2.4 2.1 3.0 122 or over 12 8 4 2.0 2.1 2.0 81 Table 30.-- M ean corpuscular hem oglobin of blood of m ale workers in 16 ferrous foundries in Illinois, according to race Mean corpuscular hemoglobin (gram x 10" l2) T otal______ Less than 27 27_______________ 28_______________ 29______________ 30_______________ 3 1 ______________ 32________ ____ _. 33_______________ 3 4 ......... 35_______________ 36_______________ 37_______________ 38_______________ 39_______________ Total Race White Nonwhite Number Total Race White Nonwhite Percent 589 389 200 100.0 100.0 100.0 1 1 0 0.2 0.2 0 1 1 0 .2 .3 0 11 5 6 1.8 1.3 3.0 42 20 22 7.1 5.1 11.0 116 70 46 19.7 18.0 23.0 137 90 47 23.3 23.2 23.5 159 115 44 27.0 29.6 22.0 70 48 22 11.9 12.3 11.0 30 23 7 5.1 5.9 3.5 4 3 1 .7 .8 .5 8 5 3 1.4 1.3 1.5 6 4 2 1.0 1.0 1.0 2 2 0 .3 .5 0 2 2 0 .3 .5 0 Table 31.-- M ean corpuscular hem oglobin concentration of blood of m ale workers in 16 ferrous foundries in Illinois, b y race Mean corpuscular hemoglobin concentration (percent) Total Race White Nonwhite Number Total Race White Nonwhite Percent Total _ 636 422 214 100.0 100.0 100.0 Less than 27______ 22 14 8 3.4 3.3 3.7 27_______________ 27 19 8 4.2 4.5 3.7 28_______________ 45 27 18 7.1 6.4 8.4 29_________ - 66 44 22 10.4 10.4 10.3 30_________ 77 43 34 12.1 10.2 15.9 31_________ . 41 29 12 6.4 6.9 5.6 32 ______________ 78 51 27 12.3 12.1 12.6 33_______________ 85 57 28 13.4 13.5 13.1 34_____ _ 63 40 23 9.9 9.5 10.8 35____________ _ 48 32 16 7.5 7.6 7.5 36_________ 31 25 6 4.9 5.9 2.8 37 _________ . 19 16 3 3.0 3.8 1.4 38_________. . . 19 14 5 3.0 3.3 2.3 39 7 5 2 1.1 1.2 .9 40 or over_______ 8 6 2 1.3 1.4 1.0 82 Since differences were noted in the total erythrocyte counts between the foundrym en and the open-hearth steelmen, special study was m ade of the records showing arbitrarily selected degrees of variation from norm al. T h e six records showing elevations above 5.7 m illions per cubic m illim eter and th e seven showing depressions of 3.5 m illions or less per cubic m illim eter were reviewed. T he six cases w ith the high erythrocyte counts had no common factor, either in their m edical or work histories, which m ight have accounted for the condition. T hey did not show any rem arkable degree of pulm onary fibrosis, since all the w orkers involved had degrees of fibrosis lim ited to ground glass one or less. (S ee figure 15 and accom panying text for classification of degrees of pulm onary fibrosis.) Of the seven records indicating th a t low erythrocyte counts were present in the workers, in two, the anem ia was probably related etio logically to cardiovascular-renal-hypertensive disease, and, in three others, it was possibly of dietary origin. In one, it was probably due to urinary blood loss of unknow n etiology, and, in the final case, no reason for the anem ia was manifest. Correlations of all the blood studies with degrees of pulm onary fibrosis appear later in this report. Vital Capacity Estim ation of pulm onary failure based on vital capacity determ ina tion is a t best a doubtful procedure ( 99) . H ow ever, since the use of the more accurate m ethods of measuring pulm onary capacity and its various com ponents (100-103) was not feasible in this investigation, it was believed th at vital capacity studies m ight be of some value. T he vital capacity records were used as actual readings, rather than making calculations as to their percentage of normal (104-107). This was done since the study group provided its own control by virtue of the fact th at dustiness varied w ith occupation as did the degree of pulm onary fibrosis observed. T able 32 shows the vital capacity readings distributed by age groups. I t is ap p aren t from this tab le th a t these d ata are in accord with similar data reported by others (99), with an anticipated decrease in vital capacity w ith increasing age. Com pared with the vital capacity data of a recent study of a some w hat younger age group in which a similar pulm onary dust hazard did not exist in the occupation, and correcting for the factor of age, no significant differences were observed. W hen the foundrym en were divided into those who smoked tobacco and those who did not, it was found th a t the vital capacity observations were sim ilar for the two groups. 83 Table 32.-- V ital capacity of m ale workers in 16 ferrous foundries in Illinois, according to age and race Vital capacity (liters) White Nonwhite Age (years) Age (years) Total Under 30 30 39 40-49 50-59 60 or over T otal Under 30 30- -39 40-49 50-59 60 or over Number T o t a l___ 1,284 219 317 234 305 209 580 192 179 130 63 16 Less than 3.0- 103 4 S 19 57 75 74 16 11 23 17 4 3 . 0 - 3 . 9 _____ 605 70 125 127 173 110 366 110 122 89 38 7 4 0 - 4 . 9 _____ 430 119 140 77 71 23 128 60 42 16 6 4 5 .0 or over, - 86 26 44 11 4 1 12 6 1 2 2 1 Percent T o t a l___ 1 0 0 .0 Less than 3.0- 12.7 3 0 - 3 . 9 _____ 4 7.1 4 . 0 - 4 . 9 _____ 3 3 . 5 5 .0 or o v e r ._ 6 .7 100.0 1.8 32.0 54.3 11.9 100.0 2.5 39.4 44.2 13.9 100.0 8.1 54.3 32.9 4.7 100.0 18.7 56.7 23.3 1.3 100.0 35.9 52.6 11.0 .5 100.0 12.8 63.1 22.1 2.0 100.0 8.3 57.3 31.3 3.1 100.0 7.8 68.2 23.5 .5 100.0 17.7 68.5 12.3 1.5 100.0 27.0 60.3 9.5 3.2 100.0 25.0 43.8 25.0 6.2 Exam ination was m ade of the vital capacities by principal occupa tional groups and years in those occupations. N o im portant associa tion was found. Correlation of vital capacities with observed degrees of pulm onary fibrosis appears later in this report. Chest Roentgenograms In evaluating the effect of dust on the lungs, the chest roentgeno gram is of param ount im portance. T his is especially true in exposures to silica dust, as in the present study. M any investigations of the effects on the lungs of silica dust inhalation have am ply docum ented the im portance of th e roentgenographic findings. It is not to be inferred, however, that correlative medical data, such as history and physical exam ination, as well as occupational history, are not to be obtained. On the contrary, these data are of great significance, espe cially for differential diagnosis. All films, as indicated above, w ere in terp reted by each of two physicians working independently. W here difference of opinion of the interpretation existed, it was resolved by conference betw een the two interpreters. Assistance from experts in the field of pulm onary tubercu losis studies was obtained for reading those films which w ere con sidered suspicious of that disease. 84 As in previous studies of the industrial pulm onary dust diseases m ade by the Public H ealth Service, the findings were classified accord ing to intensity of linear fibrosis, appearance of graininess (ground g lass), a n d nodulation. F ig u re 15 shows grap h ically th e schem e used to represent the various stages in the progression of the pul m o n ary fibrotic state due to silica d u st inhalation. F igures 16 to 22, inclusive, typical of roentgenogram s from the present study, are shown, together with the pertinent clinical data for each. Generally, films indicated as normal, linear exaggeration one, and linear exaggeration two, m ay be considered as being w ithin norm al limits or due to lung changes unrelated to the dustiness of the occupa tional environm ent. T he ground glass one appearance m ay or m ay not be due to the dust in the environm ent. Film s showing the ground glass two appearance, w ith the history of exposure to silica dust and w ith other m edical findings essentially negative, are strongly sug gestive of an effect due to the dust of the occupational environm ent. Generalized nodulation and conglomerate masses of nodules appear ing in the roentgenogram , together w ith the data of an occupational exposure to silica dust and the other m edical data, signify lung changes due to the dust. p u l m o n a r y t u b e r c u l o s is .-- T h e c rite ria for in te rp re tin g th e stage of reinfection type of pulm onary tuberculosis in this study were those of the N ational Tuberculosis Association (108). T he degree of activity of the suspected tuberculous cases was classified as probably active, probably inactive, or of doubtful activity, dependent upon the general characteristics of the roentgenographic shadows as well as upon the clinical data. Pulm onary tuberculosis was suspected from the roent genogram in 25 workers. Review of the clinical records of the workers together with the roentgenogram s revealed th at the disease was prob ab ly active in 5, p ro b ab ly in active in 8, an d of d o u b tfu l a c tiv ity in 12. It is recognized th a t activity of pulm onary tuberculous lesions cannot be evaluated on the basis of one roentgenographic exam ination and one m edical examination, especially in the absence of sputum studies. T he sputum exam inations were om itted from this study since it was felt th a t obtaining such specimens would introduce difficulties which the value of such single specimens would not counterbalance. T he data concerning the findings for pulm onary tuberculosis must, there fore, be accepted w ith caution. F urther, it is noted th a t in a t least some instances the onset of the disease m ay have preceded the tim e the worker was em ployed in the foundry industry. This factor could not be fully evaluated since pre-em ploym ent chest roentgenogram s were not available to us. 85 Figure 15. Scheme Representing the Sequence of Lung-Field M ark ings in a T ypical Case of U ncom plicated Silicosis. LINEAR Normal lung mark ings and first de gree exaggeration of linear pulm on ic markings. Second degree ex aggeration of l i n e a r pulmonic m arkings, w ith or without beading. This is the range of markings u su a lly seen on roentgen examination of chests of persons who have never worked in a dusty trade. GRANULAR First degree diffuse ground glass or grainy appear ance, not obliter ating linear mark ings. Second degree dif fuse ground glass or grainy appear ance, obliterating linear markings. ' / y -cy./y These are the earli / / y : /-y y est markings in the sequence of dust- / y ' y y y y induced changes yyyyy* which can be gen erally differenti ated from the lung changes that usu ally accom pany .*V*'*''*_***ir* a d v a n c i n g a g e , chronic bronchitis, and heart failure. SVV..* <vVV**''.*ViV*V< . . . ... NODULAR First degree dissem inated nodules up to size of miliary tubercles. Second degree dis sem inated n o d ules exceeding one m illim eter in size, emphysema present usually. * t 4 ****# *%* * * ** , - . . /** * * ' * * ; .. . . . * * * . ` % o . * . j , ** / * *.* Cases with nodular markings which may be diagnosed as stage one or stage two silicosis. CONGLOMERATE-- COALESCENT CONGLOMERATE SHADOWS . * * M ay be diagnosed as stage three silico sis. 86 Figure 16. A typical roentgenogram showing norm al lung markings. Schematic presentation shown on right. Case 2-19, age 20, white male, was born in Illinois. H e was em ployed th ree m onths as floor m o ld er's h elp er an d th re e m onths as laborer in a gray iron foundry. H is previous medical history was negative except for a tonsillectom y and sprained knee. His only com plaint was occasional abdom inal pain associated with exertion. H is physical exam ination was not rem arkable. Blood pressure was 120/70. H is tem peratu re w as 98.6 F., pulse 60, and resp iratio n 14 per m inute. U rine ex am in atio n w as negative. T h e hem o globin estim ation w as 17 gram s. H is w hite blood cell co u n t w as 9,000 with a differential count of 55 percent neutrophils, 37 lymphocytes, and eight percent monocytes. The corrected erythrocyte sedim entation rate at the end of one hour was one millim eter and hem atocrit was 42 percent. T he m ean corpuscular hemoglobin concentration was 40 percent. H is vital capacity was 4.6 liters. H is chest roentgenogram was read as normal. Figure 17. A typical roentgenogram show ing lin ear one stage of "fibro sis." Schem atic p resentation shown on left. Case 15-40, age 25, Negro, male. H e was a shakeout m an in a gray iron foundry for two and one half years. Physical exam ination was negative. Blood pressure was 130/82. H is tem p eratu re w as 98.6 F., pulse 72, and respiration 20. T he urine exam ination was negative. T he erythrocyte count was 5.32 m illion, hem oglobin d eterm in atio n 16 gram s, a n d w h ite blood cell count 9,300 w ith a differential count of 66 per cent neutrophils, three percent eosinophils, 28 percent lym phocytes and three percent monocytes. T he corrected erythrocyte sedim entation rate was eight millim eters at the end of one hour and the hem atocrit was 54 percent. T h e m ean corpuscular volum e was 102 cubic microns, m ean corpuscu lar hemoglobin 30 micromicrograms and m ean corpuscular hemoglobin concentration 30 percent. T he K ahn test was negative. H is vital capacity was 2.4 liters. H is chest roentgenogram w as read as showing linear one stage of "fibrosis." 88 Figure 18. A typical roentgenogram show ing linear tw o stage of "fibro sis." Schem atic presentation shown on right. Case 1 -4 6 , age 31, N egro, m ale. A m o ld er's ap p ren tice in a g ray iron foundry for three years. Before th at he was a sawmill laborer for two years, truck driver one year, and arm y technician three years. Physical exam ination was negative. Blood pressure was 120/80. H is tem perature was 98.8 F., pulse 80, and respiration 28. H em oglobin exam ination show ed 18 grams, and th e w hite blood cell count was 8,000 w ith a differential count of 69 percent neutrophils, one percent eosinophils, 24 percent lym phocytes and five percent monocytes. T he corrected erythrocyte sedim entation rate was one mil lim eter at the end of one hour and the hem atocrit was 46 percent. T he m ean corpuscular hemoglobin concentration was 39 percent. K ahn test was negative. H is vital capacity was 3.5 liters and his roentgenogram showed linear tw o p u lm o n ary "fibrosis." Figure 19. A typical roentgenogram showing ground glass one stage of "fibrosis." S chem atic p resen tatio n shown on left. Case 5-23, age 72, w hite male. H e was a bench m older in gray iron foundries for 50 years. H e com plained of occasional pain in his left shoulder. Exam ination showed him an obese individual with a barrel chest and kyphosis. H eart sounds were distant with an occasional extrasystole. Blood pressure was 148/78. T h e tem p eratu re was 98.8 F., pulse 80, and respiration 28. T h e hem oglobin estim ation w as 16 gram s an d the w hite blood cell count was 13,000 w ith a differential count of 65 percent neutrophils, two percent eosinophils, one percent basophils, 22 percent lym pho cytes, a n d 10 p ercen t m onocytes. T h e co rrected e ry th ro cy te sed im en ta tion rate was nine m illim eters at the end of one hour and hem atocrit was 47 percent. T he m ean corpuscular hemoglobin concentration was 33 percent. T he K ahn test was negative. H is vital capacity w as 3.3 liters. T h e roentgenogram was read as show ing ground glass one p u lm o n ary "fibrosis." 90 Figur 20. A typical roentgenogram showing ground glass two stage of "fibrosis." S chem atic p resen tatio n shown on right. Case 4-9, age 32, male, m arried, was born in Illinois. H e was em ployed as co rem ak er for 11 y ears in a g ray iron foundry. H is p re vious history was negative w ith the exception of fractures of the left forearm and right ring finger. Physical exam ination showed evidence of m oderately im paired hearing of the left ear, inflam m ation of the nasal mucosa, and infected tonsils. Blood pressure was 118/80. H is tem p eratu re was 98.6 F., pulse 74, and respiration 20. T he urine exam ination was negative. H e showed a hemoglobin of 17 gram s a n d a w hite blood cell co u n t of 9,000 w ith a differential count of 74 percent neutrophils, 23 percent lym phocytes and three percent monocytes. H is corrected erythrocyte sedim entation rate was eight m illim eters at the end of one hour and hem atocrit was 44 per cent. T he m ean corpuscular hemoglobin concentration was 39 percent. T he K ahn test was negative. H is vital capacity was 3.5 liters and his roentgenogram w as read as showing ground glass tw o p u lm o n ary "fibrosis" w ith h ilar calcification. 9) Figure 21. A typical roentgenogram showing nodular one stage fibro sis. S chem atic p resen tatio n show n on left. Case 10-161 y age 58, w hite male. H e was a cleaner and finisher (grinder) for 39 years in a steel foundry. Except for a m astoidectom y in 1926 and an appendectom y in 1945, his past history was negative. H e had no com plaints on examination. Physical exam ination showed m arked nasal septum deviation and scarring of both eardrum s with im paired hearing in the right ear. Blood pressure was 160/80. His te m p e ra tu re w as 98.8 F., pulse 76, an d resp iratio n 18. T h e hem oglobin determ ination w as 14 gram s and w hite blood cell count 10,300 w ith a differential count of 63 percent neutrophils, four percent eosinophils, 28 percent lym phocytes and five percent m ono cytes. T h e corrected e ry th ro cy te sed im en tatio n ra te w as 11 m m a t th e end of one hour and hem atocrit was 38 percent. T he m ean corpuscular hemoglobin concentration was 37 percent. T he Kahn test was negative. T h e vital capacity was 3.5 liters and his roentgenogram was read as showing nodular one pulm onary fibrosis. 92 Figure 22. A typical roentgenogram showing nodular stage two fibro sis. S chem atic p resen tatio n show n on right. Case 9-112, age 57, w hite male. H e was a bench m older for 36 years in a gray iron foundry. Exam ination of his chest showed som ewhat lim ited motion, decreased resonance and diminished breath sounds. Blood pressure was 156 /9 0 . H is te m p e ra tu re w as 98.4 F., pulse 60, a n d resp iratio n 18. T h e hem oglobin estim atio n w as 13 gram s an d th e w hite cell count was 9,400 w ith a differential count of 62 percent neutrophils, two percent eosinophils, 34 percent lym phocytes and two percent mono cytes. T he corrected erythrocyte sedim entation rate was 38 mm at the end of one hour and the hem atocrit was 34 percent. T he m ean corpus cular hemoglobin concentration was 38 percent. T he K ahn test was negative. H is vital capacity was 4.1 liters and his roentgenogram was read as showing nodular two pulm onary fibrosis. 93 o Table 33.-- Selected data for exam ined m ale workers in 16 ferrous foundries in Illinois 4* suspected of having pulm onary tuberculosis Case No. Race Ape (years) Foundry Type Service (years) Principal occupation T itle Service (years) R oen tgen ograp h ic pulmonary markings Cough Stage of disease 14-309 13-127 10-207 14-169 02-047 W h ite __________ rjn Non white _ W hite. . 10-045 03-020 14-048 02-073 14-032 14-021 13-027 14-329 10-157 09-007 09-020 04-098 W hite _____d o __________ _____ d o __________ _____d o __________ N on w h ite Whit1 _____d o __________ Nonwhite . 14 049 15-066 01-040 13-223 10-001 14-157 14-074 09-012 W h ite __________ _____ d o __________ _____d o --------------- N on w h ite W hite . . . _____d o __________ _____ d o __________ _____d o __________ 59 Steel _ 66 C ray iron 60 Steel 35 _____ d o --------------63 Gray iron 54 Steel _ 29 Gray iron 59 Steel 58 Gray iron 60 60 _____d o __________ 60 48 . . . __do_________ 67 do 38 O ray iron 62 _____ d o __________ 38 1 _____d o __________ 63 Steel 67 Gray iron. 54 _____ d o --------------49 Steel 62 Gray iron 57 S te el,. 54 _____d o --------------72 Gray iron Pulmonary tuberculosis, probably active 26 Laborer and other 26 45 Molder 45 30 Laborer and other ___ 24 6 Shakeout 6 31 M ainten ance and su p erv iso ry ___ 31 P ulm onary tub ercu los:s of doubtful a c tiv ity 30 M older _ _____ __ 30 6 Laborer and other __ __ _ _ 6 16 M ainten ance and su p erv iso ry__ 16 5 do 5 6 Coremaker 6 18 Laborer and other 18 37 M older 37 3 M ainten ance and su p erv iso ry __ 3 6 Laborer and other 6 23 Coremaker 17 42 M ainten ance and su p erv iso ry ___ 28 3 Laborer and other 2 Pulm onary tuberculosis, probably inactive 20 M ainten ance and su p erv iso ry ___ 12 31 M older 31 27 _ do 27 15 C leaning and finishing 14 49 Molder 49 25 M ainten ance and su p erv iso ry __ 23 16 C leaning and f in i s h i n g ___ 14 47 M older __ _ _ _ . 41 Linear fibrosis 2 do Linear fibrosis 1_ _ Linear fibrosis 2 _ do _ . Linear fibrosis 2 Linear fibrosis 1_ Ground glass 1 Linear fibrosis 2_ _. do. Linear fibrosis 1_ do do __ __ do - __ __ _ do do Normal Ground glass 2 Ground glass 1 Ground glass 2 Ground glass 1 Ground glass 1 do Linear fibrosis 2 Linear fibrosis 1 _ N o ______ N o ______ Y e s______ Y es______ N o ______ M oderately Do. Do. M inimal. Do. adv. N o ______ N o ______ N o ______ N o ______ N o ______ Y es______ Yes N o _____ No N o ______ N o ______ Y es. M oderately Do. M inimal. Do. Do. Do. Do. Do. Do. Do. Do, Do. adv. Yes N o ______ N o ______ Yes N o ______ N o ______ Y"es _ _ \ Tes _ _ M od erately Do. M inimal. Do. Do. Do. Do. Do. adv. T able 33 shows the pertinent data for the cases of pulm onary tuber culosis. It will be observed th a t the reinfection type of the. disease was found in 21 w hite workers and in 4 nonwhite, which yields a rate of 0.7 p erce n t for th e w hite an d 1.7 p ercen t for th e nonw hite w orkers. W hile it is recognized th a t the m ethodology pursued in another study for pulm onary tuberculosis incidence in the area in which the foundries were located was som ewhat different from th at used in the present study, the data from the other survey are presented because of their possible interest. In th at survey the rates for suspected pulm onary tuberculosis, based upon alm ost 300,000 roentgenograms, were reported as 1.75 p erce n t for w hite ad u lts of b o th sexes an d 1.32 p ercen t for th e nonw hite (1 0 9 ). In regard to this difference in rates, the im portance of the fact th at the nonw hite m en were generally em ployed in the foundry industry for a shorter period of tim e than the white men can not be evaluated at this time. The age distribution of the tuberculous w orkers in th e present study ranged from 29 to 72 years, w ith an occurrence of 19 cases in th e over-50 age group. T he relationship of the dustiness of the occupation in the foundry industry to the incidence of pulm onary tuberculosis has been discussed by m any investigators (17, 34, 35, 110-113). In the present study the relationship of pulm onary tuberculosis incidence to th at of pulm onary fibrosis was tested for significance, and none was found. In the same vein, it is noted th a t tuberculous infection was not observed as a com plication am ong th e w orkers w ith nodular silicosis. Study was m ade to determ ine w hether or not dustiness of occupa tion was itself associated with an increased incidence of pulm onary tuberculosis. Comparison was thus m ade between the two categories of cleaners and finishers, and corem akers, of which the form er was exposed to appreciably more dust than the latter. In these two work categories, it was found th at for em ployees whose roentgenogram s showed m arkings read as normal, linear one, and linear two, conditions regarded as not being related to the dust, no differences existed for the incidence of pulm onary tuberculosis. This was found for those w ith less th a n 10 years in th e occupation as well as those whose w ork experience ex ten d ed bey o n d 10 years. T h ese d a ta in dicate th a t d u sti ness of occupation, as it occurred in the ferrous foundry industry in this study, was probably not associated w ith a greater or less lk e lihood for the developm ent of pulm onary tuberculosis. Pulm onary tuberculosis was found more frequently among the steel than the gray iron foundrymen. Thus, whereas the steel foundrym en m ade up 30 percent of the total stu d y group of 1,937 men, th ey con stituted 60 percent of the cases of tuberculosis. It was found that the probability that such a distribution of the tuberculous cases between the two groups m ight occur by chance alone was one in a hundred, indicating th at the difference was significant. 95 p u l m o n a r y f ib r o s is .-- C hest ro en tg en o g ram s w ere m a d e of 1,824 of the 1,937 w orkers exam ined in this study. U sing th e classification an d criteria described in figure 15, it w as found th a t 36, or 2.0 percent, m anifested norm al lung markings; 517, or 28.3 percent, showed linear one m arkings; 728, or 39.9 percent, showed linear tw o m arkings; 375, or 20.6 percent, ground glass one; 140, or 7.7 percent, ground glass two; 24, or 1.3 percent, stage one nodular; 3, or 0.16 percent, stage tw o nodular; an d 1, or 0.05 percent, stage th ree nodular, or conglom erate silicosis. Since we exam ined only those foundrym en who were at work at the tim e of th e study, it is quite likely th a t th e incidence of pulm onary fibrosis observed was lower than had actually occurred in the industry. Obviously, those w ith m anifest lung disease, which m ight have been found previous to our study, had left the em ploym ent. For example, a review of Illinois com pensation records of ferrous foundry workers who had instituted claims for chronic pulm onary disease during the years 1941-47 showed there were 89 cases. Of these, 58 were for silicosis; 23, for silico-tuberculosis; an d 8, for tuberculosis. O nly 15 of the claim ants were over 60 years of age. T he data on the incidence of pulm onary fibrosis, com pared with studies m ade by the Public H ealth Service in other industries ( 1 1 4 -1 1 5) having a silica hazard, and for which sim ilar data were available, are shown in table 34. It appears from this table th at the foundrymen have a somewhat greater tendency than either the coal m iners or m etal m iners to develop the ground glass two roentgenographic appearance relatively early. However, among the foundry workers, th ere is a lesser ten d en cy for th e disease to progress to the nodular stage. Thus, after 20 years of exposure in the occupation, the foundrym en show a 20.9 percent incidence of ground glass two stage of fibrosis and 4.9 percent incidence of nodular silicosis; whereas, the corresponding rates for the m etal m iners are 5.8 and 21.4 percent. Among the coal m iners the rates for roentgenogram s showing ground glass tw o an d no d u lar fibrosis are 7.8 an d 2.6, respectively. At this point it might be well to consider the subject of iron deposi tion in the lungs and its possible relationship to the roentgenographic appearance of silicosis, a m atter which has evoked international interest for some years. The earliest notation on this point th at we could find in the m edical literature dates back to 1919 to a personal com m unication in which H olland ( 117) m entioned this possibility, since he recognized the relative opacity of iron to roentgen rays. H o llan d 's reference w as to th e possible occurrence of th is condition in iron miners. Iron m ining was thus the first industry in which this possibility was considered. O ther occupations th at have received attention in this 96 Table 34.-- Roentgenographic pulm onary m arkings of m ale workers in 16 ferrous foundries in Illinois com pared w ith m ale workers in U tah coal m in e s1 and U tah m eta l m in es12 according to years in industry Industry F ou n d ries_______ U tah coal m in es__ Utah m etal mines F ou n d ries_______ U ta h coal m ines __ Utah metal mines F oun dries_______ Utah coal m ines. _ U tah m etal mines F ou n d ries_______ Utah coal m ines._ U tah m etal mines F ou n d ries_______ U tah coal m ines. _ U tah m etal mines F oun dries_______ Utah coal m ines.. U tah metal mines F oun dries_______ Utah coal m ines. _ Utah metal mines F ou n d ries_______ U tah coal mines ._ U tah m etal mines 1 Reference 114. 2 Reference 115. R.oentgenograpHic pulm onary markings Total Ground glass two Total N od ular Stage 1 Stage 2 Stage 3 Number: all years 1,823 140 28 24 3 1 489 12 3 2 1 0 719 22 38 13 10 15 Number: under 10 years 966 19 1 1 0 0 200 0 0 0 0 0 389 4 0 0 0 0 Number: 10-19 y=ars 387 23 4 4 0 0 173 3 0 0 0 0 227 12 16 8 3 5 Numi, e:: 20 years o - over 470 98 23 19 3 1 116 9 3 2 1 0 103 6 22 5 7 10 Percent: all years 100.0 7.7 1.5 1.3 0 .2 0 100.0 2 .5 .6 .4 .2 0 100.0 3.1 5.3 1.8 1.4 2.1 Percent: under 10 years 100.0 2 .0 0.1 0.1 0 0 100 0 0 0 0 0 0 100.0 1.0 0 0 0 0 Percent: 10-19 years 100.0 5.9 1.0 1.0 0 0 100.0 1.7 0 0 0 0 100.0 5.3 7.1 3 .5 1.3 2 .2 Percent: 20 years or over 100.0 20.9 4.9 4 .0 0 .6 0 .2 100.0 7.8 2.6 1.7 .9 0 100.0 5.8 21.4 4.9 6.8 9 .7 97 regard have been silver polishing, welding, boiler scaling, and, finally, foundry work. T he literature ( 118-120) on the subject concerning iron m iners is to a large extent contradictory. Some d ata indicated th at iron of itself caused fibrosis; others showed th at the iron com pounds modified the roentgenographic appearance of fibrosis due to silica. Experim ental work done with the compounds from iron mines have similarly been contradictory (121, 122). Rouge (ferric oxide), when inhaled by silver polishers in their occupation, has been shown to pro duce a roentgenographic ap p earan ce of "diffuse fibrosis"; autopsy, however, failed to show fibrotic changes (12 3 ). Animal experim enta tion with rouge m anifested similar results (124). Electric arc w elders are known to be exposed in some instances to appreciable am ounts of iron and com pounds of iron in the form of fume. Cases have been reported by different investigators (125-133) in which it was suggested th a t the roentgenographic appearances of "fibrosis an d n o d u latio n " w ere in fact due to focal deposition of iron rath er th an actual fibrotic changes. In five instances, autopsies were available confirming this concept (126, 134, 135). T here have been some who have disagreed with the concept and who have held the belief th at the lung changes were truly fibrotic and were due to the silica or asbestos p resen t in th e w elding rods (136, 1 3 7 ). R esults of physiologic tests in cases of welders' siderosis have not been consistent (138-140). Boiler scalers who are exposed to appreciable am ounts of iron com pounds as well as free silica have been shown to develop pulm onary "fibrotic" changes which, on roentgenography, have ap p eared m uch m ore extensive than autopsy data were able to confirm (1 4 1 -1 4 7 ). It was believed th at here, too, deposition of iron caused the roentgeno graphic appearance. Finally, in the case of foundry workers, it is suggested th a t deposi tion of iron accounts for modification of the silicotic process as well as production of p art of the chest roentgenographic appearance itself (56, 127, 128, 1 4 8 -1 5 1 ). This, it has been alleged, is especially the case in casting cleaners. T he foregoing data seem to point to the following facts: (1 ) T h at electric arc welders who m ay be exposed to high concentrations of welding fumes m ay develop iron deposition in the lungs which in some instances is roentgenographically very difficult to distinguish from nodular silicosis, b u t which is not associated w ith pulm onary fibrosis; and (2 ) th at in exposure to iron and silica dust together, there m ay be a modification of the fibrotic process by the sim ultaneous presence of the two agents, the iron causing a slowing of the fibrotic process. In the present investigation, the m atter of iron deposition in the lungs received lim ited attention. T he incidence of the various degrees 98 of pulm onary roentgenographic m arkings was com pared for cleaners and finishers, and sandblasters, of which the form er were exposed to rela tiv ely higher levels of iron dust, as show n b y exam ple in ta b le 3. This com parison failed to show th at the exposure to the larger am ounts of iron resulted in appreciably more m arked pulm onary roentgeno graphic markings. T h e 11 roentgenogram s of th e casting cleaners an d finishers w hich showed nodulation were reviewed and com pared with a similar group of roentgenogram s of foundry workers whose exposure to iron was very m uch less. Again no differences were ap p aren t in the two sets of roentgenograms. From the lim ited study of this problem it would appear, therefore, th at the data in the present survey do not support the concept th at the factor of iron is of significance in the roentgeno graphic appearance of the lungs in foundry workers. I t is pointed out, however, th at 28 cases, the num ber of workers in the present study who showed nodular fibrosis, were too few to perm it a m ore thorough evaluation of this problem. Only when adequate autopsy m aterial becomes available for such cases will this m atter possibly be satis factorily clarified. T he medical records of the 28 persons whose chest roentgenograms showed nodular fibrosis were reviewed, and the significant data from these case records are shown in table 35. T he m en ranged in age from 45 to 73 years; 23 of them were over 50 years of age. It will be observed from the table th at all were white persons. T he absence of nonwhite workers in this series m ay possibly be explained by the fact th at the nonwhite had spent significantly fewer years in foundry work as observed in this study. Exam ination of the occupational histories of the group revealed that 18 w ere gray iron w orkers an d 10, steel w orkers, a ratio sim ilar to th a t of these groups in th e en tire study. Of the 18 iron workers, 14 had the principal occupation of molder, two were cleaners and finishers, one was a laborer, and one, a shakeout man. Of the steel foundrym en, 9 were cleaners and finishers, and 1 was a laborer. T he tim e spent in the principal occupation by each of the m en approxi m a ted closely th e to ta l y ears each h ad sp e n t in fo u n d ry w ork; th a t is, 14 to 52 years. T h ere w ere 2 m en whose years in foundry w ork were less th a n 14; 1 h ad 13, an d th e o th er five y ears of fo u n d ry experience. T he first of these had been a burner for a significant p art of his life in foundry work and m ay fall into the category of persons exposed to appreciable am ounts of iron fume, a group so well described by H am lin (149). For the second worker, whose experience in the foundry was allegedly five years, there were m any reasons w hy his history was considered unreliable. T hree of the workers w ith nodular fibrosis gave a history of prob- 99 100 Table 35.-- Selected data for exam ined m ale workers in 16 ferrous foundries in Illinois showing nodular roentgenographic pulm onary markings Case No. Race 16-025 W hite. . . . . 09-112 10-154 11-022 W hite do _____ d o ----------- 13-077 11-003 10-161 11-001 16-001 04-050 04-027 11-002 13-113 13-125 13-139 14-143 10-164 10-122 14-138 14-068 04-045 03-010 09-070 02-016 14-115 14-128 10-173 13-276 W hite dn _____d o _______ _____ d o _______ do do do do rio do do do _____ d o _______ _____ d o ------------ do do _____d o _______ _____ d o _______ do _____ d o _______ do do do _____d o _______ Age (years) 70 57 59 59 64 50 58 60 62 65 57 63 67 56 57 57 65 54 53 57 45 48 17 45 54 73 46 60 Foundry Type Service (years) G ray ir o n ____ 52 Gray iron 36 Steel _ 34 G ray ir o n ____ 21 Gray iron 45 do 40 Steel 39 G ray ir o n ____ 38 do 36 do 35 do 35 do 34 do 37 do 33 do 32 Steel 31 _____ d o _______ 30 _____ d o _______ 28 do 35 do 27 G ray ir o n ____ 25 _____ d o _______ 24 do 23 _____ d o _______ 18 S te e l.. 15 do 14 do 13 G ray iro n ____ 5 Principal occupation T itle Service (years) Cough Blood pressure V ital capacitj (liters) S ed im en tation rate (mm in 1 hour) H em oglo bin (grams per 100 cc of blood) Nodular three M older . . _ _ _ ________| Nodular two M older __ _______________ C leaning and f in i s h i n g ___ M old er. _ _____ ______ __ Nodular one M older __ _ _ __ __ _ d o ______ _ __________ C leaning and finishing____ Molder . . . . _____ do,, _ _ __ __ do __ do_ do_ _ __ do _ __ _ __ _ _ _ _ do ____ d o __ _ ____ Cleaning and finishing Laborer and o t h e r _____ C leaning and fin ish in g____ do_ _ __ do ________ _ _ M older ... C leaning and fin ish in g____ Laborer and o t h e r _______ C leaning and fin ish in g____ ____do __________ _ do_ _ _ __ __ ____ do_ __ __ _ Shakeout _ .. 52 1 N o _____ 1 1 6 3 / 94 1 36 N o _____ 1 5 5 / 90 34 N o _____ 1 6 0 /1 1 2 14 N o _____ 1 5 0 / 86 45 N o _____ 1 8 0 /1 0 0 40 N o _____ 1 3 0 / 84 39 N o _____ 1 6 0 / 80 38 N o _____ 1 2 0 / 70 36 N o _____ 1 2 8 / 76 35 N o _____ 9 0 / 70 35 130/ 84 34 Y e s_____ 1 5 6 /1 0 2 32 N o _____ 1 5 6 / 96 32 N o _____ 1 5 0 / 90 31 N o _____ 1 4 0 / 82 31 N o _____ 1 2 2 / 80 30 N o _____ 1 5 0 / 80 28 N o _____ 1 3 6 / 90 26 N o _____ 1 3 2 / 90 25 Y e s_____ 9 5 / 70 25 N o _____ 1 5 4 /1 0 0 24 N o _____ 1 4 0 / 80 23 N o _____ 1 5 6 /1 0 0 18 N o _____ 1 2 0 / 82 15 Y e s_____ 1 4 0 /1 0 0 14 Y e s_____ 1 3 5 / 80 7 N o _____ 1 2 2 / 80 5 N o _____ 1 5 0 / 90 2.4 1 4.1 3 .6 3 .0 2 .4 3 .8 3 .5 4 .2 3.3 3 .0 2.4 3 .3 2 .5 2.3 3.4 3 .0 3 .9 3 .6 2 .8 4.1 4 .5 3.4 3 .5 4.1 3 .8 3 .4 2.4 5 1 8 1 7 15 17 11 9 25 13 32 27 8 31 17 13 21 8 10 9 9 12 1 H 11 7 15 14 15 1 13 16 15 16 14 14 16 14 14 15 17 12 14 13 16 15 14 15 15 15 16 13 Total leuco cyte count 9 ,7 0 0 9 ,4 0 0 11,400 5,100 9 ,4 0 0 9,200 10,300 11,100 5,100 14,000 11,400 10,600 8 ,0 0 0 4 ,4 0 0 9 ,0 0 0 11,200 12,300 11,600 11,400 8,800 9 ,0 0 0 11,800 6,200 ably significant inorganic dust exposure in other activities prior to their foundry experience; one was em ployed in brick and tile m anufacturing, one perform ed welding, and the third w orked in a brick yard. A m ong th e 18 g ray iron fo u n d ry m en w ith n o d u lar fibrosis th ere w ere 14 m olders; 11 w ith n o d u lar stage one, 2 w ith n o d u lar stage two, and 1 with nodular stage three. T he rem aining gray iron foundrym en were two cleaners and finishers, one laborer and one shakeout man, all w ith n o d u lar one stage of fibrosis. Of the 10 steel foundrym en, 8 cleaners and finishers had nodular stage one fibrosis, one cleaner and finisher had nodular stage two, and one shakeout m an had nodular stage one fibrosis. I t thus appears th a t for the iron foundrym en the m olders have a higher incidence of nodular silicosis; whereas, for the steel workers the cleaners and finishers have the higher incidence. T he high incidence rate for the m olders among the gray iron foundrym en is probably due to their long exposure. Of the two iron foundrymen, w ith nodular two fibrosis, one had m ore th an 25 years' experience. T he one m an w ith conglom erate silicosis had 52 years in his occupa tion as a m older. Six of the nine steel w orkers w ith nodular one stage of fibrosis had 25 years or m ore of experience. T he one steel worker w ith nodular two fibrosis had 34 years in his principal occupation. Review of the symptoms of this group revealed th at four complained of cough and one of chest pain. It is of interest to note th a t in no instance w as dyspnea recorded. V ital capacity ranged from 2.4 to 4.5 liters, w ith the distribution of the vital capacity records for the group similar to that of the total group studied, when correction was m ade for age. Com parison of the various hem atologic studies for this series w ith those of the entire group of foundrym en showed no significant differences when correction was m ade for age. Correlation of Pulm onary Fibrosis w ith Other Data PULMONARY FIBROSIS AND PREVIOUS OCCUPATION.----As m e n t io n e d above, there were 73 foundrym en, approxim ately four percent, whose work histories included periods during which their em ploym ents were in dusty trades, other than foundry work. Of these, 67 had been miners; 56 in coal an d 11 in m iscellaneous kinds of m ining. Of th e rem aining six, one h ad w orked in a coal m ine and a pottery; one, as a stone cutter; two, in stone quarries; and two, in rock crushing. T he medical and historical data for each of these men were reviewed. On the basis of the general knowledge of the degree and nature of the dustiness of their form er trades, as well as upon the tim e spent in the form er and present occupations, efforts were m ade to determ ine w hat influence the form er dusty occupation probably had upon the degree of pulm onary fibrosis observed in the present study. It was believed th a t in only a relatively small num ber was there a 101 likelihood th at the former occupation was etiologically of importance. All of these had ground glass roentgenographic changes, some having ground glass one and some, ground glass two. It is of som e in terest to note that, of the 28 foundrym en showing nodular fibrosis, only three had work histories of previously lim ited dust exposure; one had been em ployed in a brick yard; and a second, in brick and tile m anufactur ing; the th ird was a w orker who had been a w elder previously. On the basis of the foregoing data, it is not felt th at previous occupa tion in a dusty trade, other than in foundries, had a significant influ ence on the degree of pulm onary fibrosis observed in this study. F urther evidence lending support to this observation was found by com paring the frequency in this study of the occurrence of previous dusty occupations of groups showing varying degrees of pulm onary fibrosis. It is not possible to evaluate fully for the foundrym en studied pre vious dustiness in ferrous foundry work. As has previously been stated in this report, there is good reason to believe th a t dust conditions in general in th e fo u n d ry in d u stry have im proved in th e p a st 10 to 20 years. T he lower dust levels found in our study and another recent study (2 0 ), as com pared to those found in earlier investigations, tend to bear this out. Thus, it is likely th a t in m any instances the pulm onary fibrosis observed was due in great p art to higher dust concentrations w hich p ro b ab ly existed 10, 15, or m ore years previously in foundries. p u l m o n a r y f ib r o s i s a n d p r i n c i p a l o c c u p a t i o n .-- T a b le s 36 a n d 37 show the incidence rates of pulm onary fibrosis, as observed by roentgenogram, for the various occupational groups of the ferrous foundrym en according to years of experience. It will be observed from these tables th at pulm onary fibrosis, in the degrees of ground glass tw o and nodular, occurred in 10.0 percent of the total of gray iron w orkers, an d for th e steel w orkers a p ercen t of 7.9 w as yielded; th e difference between these two rates was not statistically significant and is contrary to m any previous reports of foundry studies (32, 36, 38, 49). In both types of ferrous foundry workers there was a progressive increase of incidence rates w ith increasing years of exposure from less than ten to over 20 years. Further, the fact th at no significant differ ence was found betw een the incidence rates of pulm onary fibrosis between gray iron foundrym en and steel foundrym en was not due to any difference in years of exposure between these two groups, each considered as a whole, since the average num ber of years of experience of gray iron foundrym en and of steel foundrym en respectively was approxim ately the same in this study. R eference is now m ade to colum n A of tab le 10 from w hich it will be observed th a t th e w eighted d ust exposures as defined w ere 3.2 m ppcf for shakeout men, 2.7 for cleaners and finishers, 2.7 for molders, 102 Table 36.-- D istribution of m ales in 16 ferrous foundries in Illinois with respect to degree of roentgenographic pulm onary markings according to years in principal occupation for gray iron and steel foundries Total Years in principal occupation Less than 10 10 to 19 20 or over Principal occupation Roentgenographic pulmonary markings Ground glass one or less Ground glass two and nodular Ground glass one or less Ground glass two and nodular Ground glass one or less Ground glass two and nodular Ground glass one or less Ground glass two and nodular Total T o ta l .... 1,654 168 1,023 27 331 38 300 103 Shakeout . . 199 11 166 5 23 5 10 1 C leaning and finishing___ 286 38 202 7 64 15 20 16 M older 436 84 214 6 94 8 128 70 Laborer and other _ 353 23 267 7 52 5 34 11 M aintenance and super- visory . 155 5 82 1 38 3 35 1 Coremaker _ . 225 7 92 1 60 2 73 4 Gray iron foundries Total -, 1,056 117 670 17 182 21 204 79 Shakeout _ 140 8 118 4 14 4 8 0 C leaning and finishing___ 159 9 125 1 26 4 8 4 M older _ . _ _ _ 313 77 147 4 68 5 98 68 Laborer and other. _ 223 14 178 6 30 5 15 3 M aintenance and super- visory _ . 90 3 46 1 22 1 22 1 Coremaker _ _ 131 6 56 1 22 2 53 3 Steel foundries Total ... 598 51 353 10 149 17 96 24 Shakeout __ 59 3 48 1 9 1 2 1 C leaning and finishing___ 127 29 77 6 38 11 12 12 M o ld er_______________ 123 7 67 2 26 3 30 2 Laborer and o t h e r _____ 130 9 89 1 22 0 19 8 M aintenance and super- visory.. . . . . . 65 2 36 0 16 2 13 0 Coremaker. _ _ _ _ _ _ 94 1 36 0 38 0 23 1 a n d 1.0 for corem akers, all for g ray iron foundrym en. T hus, all o th er factors being equal, it m ight be expected th a t the frequency of the occurrence of pulm onary fibrosis would be in proportion to those w eighted d u st exposures. F ro m tab les 37 an d 10 it is n o ted th at, in the gray iron foundrymen, among the four occupational groups of 103 Table 37.-- Percent ot m ale workers in ray iron foundries in Illinois w ith roentgenographic pulm onary m arkings of ground glass two or nodular according to years in principal occupation (derived from table 36) Principal occupation Total Years in principal occupation Less than 10 10 to 19 20 or over T o ta l___ _ S h a k e o u t ____ _ Cleaning and finishing M older _ _ _________ _ Laborer and other _ _ _ M aintenance and su pervisory___ Coremaker _ ___________ 10.0 5 .4 5 .4 19.7 5.9 3 .2 4 .4 2.5 10.3 3 .3 22.2 .8 13.3 2.6 6.8 3 .3 14.3 2 .1 4 .3 1.8 8 .3 27.9 0 33.3 41.0 16.7 4 .3 5 .4 shakeout men, molders, cleaners and finishers, and corem akers, the incidence rates of pulm onary fibrosis show a trend in the expected direction; th a t is, as th e w eighted d u st exposures decrease, th e rate s for pulm onary fibrosis decrease. T his tren d is probably som ew hat m ore apparent when the groups of molders, and cleaners and finishers, the two occupational classes having sim ilar dust exposures, are considered together. T h e m ajor aberration observed in tab le 37 is th a t there are no cases of pulm onary fibrosis am ong the shakeout m en after 20 years a t this occupation. T his is in p a rt probably due to the fact th a t th ere were only eight shakeout men with such a length of experience. It is pointed out th a t th ere was a higher incidence rate for fibrosis among the m olders th an am ong cleaners and finishers, in both of which the weighted dust exposures were similar. This difference m ay possibly be accounted for by the fact that molders had more years of experience in their occupation. Further, the iron content was appreci ably higher for the cleaners and finishers than it was for the molders. T h e p art th a t iron itself m ay have played in the roentgenographic appearances observed cannot be evaluated at this time. This m atter was discussed in detail in another section of this report. Knowledge of particle size distribution of inorganic dust which m ay be inhaled is of im portance in th e evaluation of th e effects of th e dust. In this study such m easurem ents were m ade and appear in table 4. It is doubted th a t the m oderate variations noted are of physiological significance for the airborne dust of the ferrous foundry. PULMONARY FIBROSIS AND HISTORY OF FAMILIAL TUBERCULOSIS.--- I t is generally accepted th a t not all persons equally exposed to silica dust develop silicosis. Sim ilarly, not all persons equally exposed to 104 tubercle bacilli develop the reinfection type of pulm onary tubercu losis (1 5 2 -1 5 5 ). T he basis of susceptibility and im m unity is not fully understood in either of these instances. In the present study, it appeared useful to test w hether or not, in both instances, a sim ilar m echanism m ight be operative. Since heredity is accepted by m any as a factor in susceptibility to tuberculosis, the incidence of pulm onary fibrotic changes due to the silica dust in the ferrous foundries was tested against the occurrence of a history of familial tuberculosis. No such relationship was found since those whose lungs showed the degree of fibrosis of ground glass two or evidence of further advanced fibrosis, had a familial pulm onary tuberculosis incidence not significantly different from those who did not have such roentgen evidence of pulm onary fibrosis. PULMONARY FIBROSIS AND OTHER DISEASE ENTITIES OF RESPIRATORY a n d c a r d io v a s c u l a r s y s t e m s .-- T h e diseases co n sid ered w ere b ro n chial asthm a, chronic nasal sinusitis, pleurisy or pneum onia, chronic tracheobronchitis, and heart disease. These diseases, when tested separately, as well as a group, failed to show significant correlation w ith the occurrence of pulm onary fibrosis. PULMONARY FIBROSIS AND CERTAIN SYMPTOMS, PULSE RATE, AND w e ig h t d e v ia t io n s .-- T h e p u lm o n a ry ro en tg en o g rap h ic findings w ere correlated w ith the sym ptom s generally believed to be most fre quently associated w ith silicosis; nam ely, dyspnea, cough, and chest discomfort (or pain). Only cough and dyspnea were found to be positively associated w ith the degree of pulm onary fibrosis to the extent th at such fibrosis occurred in this study. T he pulse rates did not show association with the degrees of pul m onary fibrosis. T he findings in this study of the deviation of the weight from the average were discussed previously. W hen the data were distributed according to observed degrees of pulm onary fibrosis, no association was evident. T his is not surprising in view of the fact th a t in this study th ere w as only one case of conglom erate silicosis and no instances of silico-tuberculosis. PULMONARY FIBROSIS AND FREQUENCY OF COMMON COLD.--- D a ta On the frequency of the common cold were divided into two groups, of which the first represented those workers who gave histories of hav ing had two or less colds during the previous year and the second represented those who had had more than two colds during th a t time. Recognizing the difficulty of obtaining reliable inform ation about common cold frequency beyond the previous year, we believed that one might, for present purposes only, consider the frequency of this disease for the past year as representing possibly its frequency in other years as well. T hese data, when correlated w ith the observed 105 pulm onary fibrotic conditions, failed to show association. Thus, it would seem th a t the history of frequent com mon colds, as here defined, does not m ake m ore or less likely the developm ent of pulm onary fibrosis from exposure to siliceous dust as found in the present study. p u l m o n a r y f ib r o s is a n d b l o o d f i n d i n g s .-- R e p o rts on th e b lood findings in pulm onary fibrotic conditions due to inorganic dusts, especially silica, have appeared from tim e to tim e in the m edical literature (156-165). In a study reported from the Public H ealth Service (1 6 6 ), suggestive data of a positive relationship in this regard were reported for erythrocyte sedim entation rate and for differential leucocyte count. T he hem atologic data collected in the present study perm itted further extension of these observations. It was found that, whereas no correlation with degree of pulm onary fibrosis existed for erythrocyte count, hem atocrit value, hemoglobin estim ation, m ean corpuscular volume, m ean corpuscular hemoglobin, and m ean corpuscular hemoglobin concentration, significant correla tions were found between the degree of lung changes and the total leucocyte count as well as w ith the corrected erythrocyte sedim enta tion rate (tables 38 and 39). As the degree of pulm onary fibrosis increased for the group, the total leucocyte counts were elevated, and the corrected erythrocyte sedim entation rates were found to be more rapid. Similar observations have been m ade by others and have been variously interpreted (157, 158). T he present data do not w arrant the opinion that the blood changes observed indicate infection superim posed on the pulm onary fibrosis. R ather, it appears th at the lung fibrosis m ay itself be associated with an elevated leucocyte count and an increased erythrocyte sedim enta tion rate, confirming an opinion expressed in recent publications on this subject (157, 1 5 8 ). I t is of interest to note th a t for the 28 cases of nodular silicosis the corrected sedim entation rate after one hour was over te n m illim eters in 16 persons an d u n d er ten m illim eters in 11 persons. T he one w orker w ith conglom erate silicosis had a sedim enta tion rate of five m illim eters. It is recognized th a t conglom erate silicosis, a condition som etim es associated with an increase of erythrocyte count and hemoglobin, occurred in only one instance in th e p resen t study. T hus, it is to be noted th at to the degree th at pulm onary fibrosis was found in this study, there was a tendency for the erythrocyte sedim entation rates to be accelerated and the total leucocyte counts to be elevated. Consideration was given to the possibility th at the presence of com plicating pulm onary tuberculosis could have been responsible for the accelerated erythrocyte sedim entation rate. This factor appeared to be of doubtful im portance in the present study for the following reasons: (1 ) Tuberculosis was not found in any of the 28 cases of 106 Table 38.-- Total leucocyte counts for m ale workers in 16 ferrous foundries in Illinois according to roentgenographic pulm onary m arkings Total leucocyte count per m m 3 Total Roentgenographic pulm onary m arkings Norm al, linear one, or linear two G round glass on \ G round glass two N odular N um ber T o ta l_______ 1,425 976 306 120 23 Less th a n 5,000___ 22 17 2 2 1 5 ,0 0 0 -6 ,9 0 0 _______ 279 209 59 8 3 7 ,0 0 0 -8 ,9 0 0 _______ 479 354 94 29 2 9 ,0 0 0 -1 0 ,9 0 0 ______ 340 221 76 35 8 1 1 ,000-12,900_____ 195 111 49 27 8 1 3 ,000-14,900_____ 88 52 22 13 1 15,000 or o v e r. 22 12 4 6 0 Percent Total , , Less th a n 5 ,000___ 5 ,0 0 0 -6 ,9 0 0 _______ 7 ,0 0 0 -8 ,9 0 0 _______ 9 ,0 0 0 -1 0 ,9 0 0 ______ 1 1 ,000-12,900_____ 1 3 ,000-14,900_____ 15,000 or o v e r_____ 100.0 1.5 19.6 33.6 23.9 13.7 6 .2 1.5 100.0 1.7 21.4 36.3 22.7 11.4 5 .3 1.2 100.0 0 .7 19.3 30.7 24.8 16.0 7 .2 1.3 100.0 1.7 6 .6 24.2 29.2 22.5 10.8 5 .0 100.0 4 .4 13.0 8 .7 31.8 34.8 4 .3 0 nodular fibrosis observed; (2 ) the erythrocyte sedim entation rates observed for the 25 cases of pulm onary tuberculosis found in this stu d y ran g ed from 5 to 23 m illim eters, w ith a m ean of 13 m illim eters; and (3 ) these cases were too few to affect the average of the sedi m entation rates observed for the relatively large num ber of cases of diffuse pulm onary fibrosis studied. -- --------raww-i-:' ABEn Increased speed of settling of erythrocytes occurs in m any disease states and is therefore a nonspecific test, as is th e occurrence of leucocytosis or an elevated tem perature. Thus, in general, it is used to call attention to occult diseases or as a m eans of gauging the progress of recognized disease states. In the present study, the presence of certain of such disease states, which could have given rise to an acceleration of th e sedim entation rate, was likely. N evertheless, there is no reason 107 Table 39.-- Corrected sedim entation rates of erythrocytes for m ale workers in 16 ferrous foundries in Illinois according to roentgenographic pulm onary m arkings and age Corrected sedi mentation rate (mm in 1 hour) Total Iloentgenographic pulmonary markings Normal, linear one, or linear two' Ground glass one Ground glass two Nodular Number, under 40 years T otal______ 892 739 134 19 0 Less than 10 _ 556 474 70 12 0 10 or over 336 265 64 7 0 Number, 40 years or over Total 917 534 235 116 32 Less than 10 . _ 369 239 88 32 10 10 or over 548 295 147 84 22 Percent, under 40 years Total - ... Less than 10 10 or over 100.0 62.3 37.7 100.0 64.1 35.9 100.0 52.2 47.8 100.0 63.2 36.8 Percent, 40 years or over Total .... Less than 10 _ . . 10 or over . 100.0 40.2 59.8 100.0 44.8 55.2 100.0 37.5 62.5 100.0 27 6 72.4 100.0 31.3 68.7 to suspect th at such disease states would be m ore frequent in those with pulm onary fibrosis than they would be in those w ithout pul m onary fibrosis. T his last hypothesis was tested and was found to be the fact. Thus, it is felt th a t the elevated sedim entation rate was prob ably due to the pulm onary fibrosis itself as it was found in the present study. p u l m o n a r y f ib r o s i s a n d v it a l c a p a c it y .-- T o th e d eg ree th a t pulm onary fibrosis was observed in the present study, it is doubtful th at one would anticipate a decrease in vital capacity below normal. 108 Further, it m ust again be noted that the men examined were perform ing hard labor, which they could not do with any ease had they m ani fested signs of respiratory failure. It is not surprising, therefore, to find th a t vital capacity in the study did not show a decline with increasing degree of pulm onary fibrosis. Sim ilar observations have been m ade by others (99). Thus, as shown earlier in this report, the degree of dustiness in the occupation as well as duration of em ploym ent was coincident with decrease of the vital capacity. Nevertheless, this alteration was apparently not due to the developm ent of pulm onary fibrosis. p u l m o n a r y f ib r o s i s a n d t o b a c c o s m o k i n g .-- W h e n te ste d , th e data failed to show a relation between the smoking of tobacco and the lung roentgenogram findings. DENTAL FINDINGS D ata were gathered to determ ine the possible effects of the direct action of atmospheric contam inants on the oral structures and to note any oral changes that m ay have resulted from systemic disturbances of occupational origin. In addition to these data, pertinent inform ation was obtained on general oral health status. O ral exam inations w ere p erfo rm ed on 1,903 em ployees of th e 16 ferrous foundries. T he dental exam ination was perform ed concurrently with the medical examination, utilizing standard dental equipment. T h e conditions w ere reco rd ed on th e form show n as figure 14, an d were lim ited to those which could be observed with the aid of a plane m outh m irror and a diagnostic light properly adjusted to assure m aximum illum ination. Bite-wing roentgenogram s were obtained from a num ber of the men examined. T he age distribution of the white and nonwhite workers who had a den tal exam ination is given in ta b le 40. I t will be noted th a t the Table 40.-- N u m b er and percent of m ale workers in 16 ferrous foundries in Illinois who were given dental examinations, according to age and race Age (years) Number White Non white Percent White Non white Total _ Under 25__ 25-34___________________ 35-44___________________ 4 5 - 5 4 ___________________ 55 or over. _ ___ 1,312 112 280 272 256 392 591 100.0 101 8.5 188 21.4 163 20.7 103 19.5 36 29.9 100.0 17.1 31.8 27.6 17.4 6.1 109 distributions are not similar. Thus, 29.9 percent of the w hite m ales are 55 years of age or over, as com pared w ith only 6.1 p ercen t of the nonwhite males. D ental Caries In an effort to determ ine w hether or not any racial differences existed relative to dental caries, the white and nonwhite were divided into those w ith teeth, and those who were edentulous. T able 41 shows, according to age group, the num ber of untreated carious, missing, and filled teeth per one hundred persons. These data are presented on the basis of 32 teeth per person. In the group under 25 years of age the two races show about the same num ber of untreated carious teeth, but with advancing age the nonwhite exceed the w hite in each age group. Generally, the nonwhite m ales had more untreated caries than the white. W ith respect to miss ing and filled teeth, respectively, the reverse is shown. It is of further T a b le 4 1 --N u m b e r of u n trea ted carious teeth , m issing teeth, and filled teeth per 100 males and num ber of edentulous persons among workers in 16 ferrous foundries in Illinois according to age and race Edentulous Nonedentulous Age (years) Number of males Number of males Number of teeth per 100 males Untreated caries Missing Filled White Total 207 1,105 229 911 360 Under 25 0 112 277 401 490 25-34____________ 5 275 208 630 592 35-44____________ 32 240 229 857 399 45-54____________ 47 209 216 1,180 216 55 or over 123 269 241 1,248 144 Nonwhite T o ta l______ 28 563 294 458 158 Under 25 _ - 0 101 275 203 183 25-34____________ 0 189 264 284 202 35-44___________ 6 156 315 529 124 45-54____________ 16 87 354 769 132 55 or over. __ _ . 6 30 267 1,150 40 N o te : Based on 32 teeth. 110 interest to note that for all age groups the white males had nearly twice as many teeth missing and more than twice as many filled as the nonwhite. In addition to com paring the data of the white and nonwhite groups, the rate of decayed, missing, and filled teeth for white m ale foundry w orkers is evaluated. F or such evaluation, d ata for m ale foundry workers are com pared with similar inform ation from a study of mine and sm elter workers (167). In making this comparison the third m olars are excluded; consideration is th u s given to 28 te eth for each mouth. T he pertinent data are presented in table 42. It will be noted that, for all ages of the four industrial groups studied, the foundry w orkers have less untreated carious teeth. F or each group studied, there is in general a steady decline in the num ber of u n treated carious teeth w ith advance in age. For each respective age group the foundry workers have fewer teeth missing than the coal miners, m etal miners, and sm elter workers. W hen consideration is given to all age groups combined, the foundry workers have more teeth missing than the other groups, a condition attributable to the greater proportion of foundry workers who were 55 years of age and over. F o r all ages, the rate of filled teeth for the foundry w orker is less than th at of the m etal mine and sm elter workers but more than was observed am ong the coal miners. In the two age groups under 35 years, the num ber of teeth filled per hundred m ales for the foundry worker is greater th an was observed in the m etal, coal mine, and sm elter workers, respectively, w ith the exception of the 25-34 year age group of sm elter workers who presented a slightly higher rate of filled teeth. For age groups 35-44 and over, the m etal mine and sm elter workers have a higher rate of filled teeth than the foundry workers. Consider ing each age group, the foundry workers had a higher rate of filled teeth than the coal miners. F o r all industries there is a gradual increase in the rate of missing teeth w ith advancing age. G enerally speaking, the rate of filled teeth and carious teeth per hundred males steadily decreases with advancing age. It follows, therefore, th at w ith the advance in age, fewer teeth rem ain to becom e carious or filled. W hen consideration is given to all three factors-- decayed, filled, and missing teeth com bined for respective age groups-- the foundry workers have a slightly more favorable experience, w ith the exception of coal m iners in age groups under 34 years. Roentgenography was used on a limited num ber of workers to deter mine the num ber of interproxim al caries which had penetrated the enamel, in addition to those found by an exam ination with a m outh m irror and diagnostic light. F or this purpose, 788 plates, containing two quadrants w ith the upper and lower biscuspids and molars, were 111 Table 42.-- N um ber of untreated carious teeth, missing teeth, and filled teeth per 100 white m ales among workers in 16 ferrous foundries in Illinois according to age compared with m etal mine, coal mine, and smelter workers Age (years) Number of workers examined Number of teeth per 1DO males Untreated caries Missing Filled Foundries T otal_____ Under 25 _ 25-34_____ 35-44__ _____ 45-54____ 55 or over _ 1,312 172 1,010 272 112 234 220 470 280 198 463 504 272 176 874 317 256 152 1,277 163 392 146 1,547 89 Total Under 25 25-34______ 35-44_____ 45-54___ 55 or over Metal mines1 690 272 840 373 83 363 283 425 308 328 529 431 162 230 946 352 90 171 1,576 290 47 285 2,083 128 Total .. . Under 25 . 2 5 - 3 4 _______ 35-44____________ 4 5 - 5 4 ___ 55 or over Coal mines1 459 289 927 230 70 389 297 291 155 358 498 273 131 268 994 281 82 160 1,888 61 21 81 2,014 52 Smelters1 T otal....... _ _ 1.216 239 899 404 Under 25 __ .. 113 414 281 455 2 5 - 3 4 ___________________ 395 320 496 515 35-44___________________ 347 212 939 420 4 5 - 5 4 ___________________ 256 138 1,386 276 55 or over ...... 105 76 1,763 188 1 Reference 167. N o t e : E d en tu lo u s p ersons are in clu d ed , and rates are b ased Qn 2 8 teeth . 112 selected from 394 persons roentgenographed. Selection of the plates was m ade on the basis of definite interpretation of the picture of each of the teeth present in all four quadrants. T he interproxim al surfaces of the upper and lower teeth included for interpretation were those between the distal surfaces of the first bicuspids and the mesial surfaces of the third molars. T he 394 persons whose bite-wing roentgenogram s were selected for study represented all age groups. W ith the use of a m outh m irror and diagnostic light, the exam ination of all the teeth present showed a total of 898 untreated carious teeth. T he interpretation from the roentgeno graph of the posterior areas previously described revealed the presence of 198 m ore untreated interproxim al carious lesions. T his figure represents 22 percent m ore carious lesions than were observed with the use of m outh m irror and diagnostic light alone. Selected Abnorm alities of Oral C avity Inform ation reported in the study also included data on abnorm al ities and pathological conditions affecting the soft tissues and support ing structures of the oral cavity. D ata presented in table 43 are based on the abnorm alities or pathological conditions of the oral structures affecting th e lip, oral mucosa, tongue, palate, gingiva, uvula, and velum. T he abnorm alities are reported according to num ber and percent of persons affected. T he conditions reported are lim ited to keratosis, leukoplakia, fissures, herpes simplex, inflam m ation, and varicosities. These data are presented principally with the thought th at they m ay be of value as baseline inform ation in future studies since com parable data were not available. In all instances, w ith the exception of the oral mucosa and tongue, the white males experienced more keratosis of the structures listed than the nonwhite. For the nonwhite, keratosis occurred on the buccal oral mucosa along the inter-dental line. T his m ay be attrib u ted to the local m echanical irritation caused during m astication by the forcing of the oral mucosa over the occlusal surface by the muscles th at sup port the buccal mucous membranes. T here were no cases of leuko plakia observed among the nonwhite group. A fissured, or scrotal tongue, is a condition described as a congenital m alform ation affecting the surface of the tongue by presenting deep furrows; one furrow m ay extend anteroposteriorly, and others, laterally over the entire surface (172). For the group studied little racial dif ference existed w ith reference to this condition, as the white showed an incidence of 6.0 percent and the nonw hite, 6.1 percent. A tortuous distention of the ranine veins and their venules, referred to as varicosities of the tongue, was observed in 41.0 percent of the w hite and 13.0 percent of the nonw hite. It is stated th a t such a condi- 113 Table 43.-- N um ber and percent of m ales showing selected abnorm ali ties of oral cavity among workers in 16 ferrous foundries in Illinois according to race Abnormality White Pact; Nonwhite Number Percent Number Percent Lip: Keratosis ____ _ 299 22.8 Leukoplakia _ _ . 8 0.6 Herpes _ _. 18 1.4 61 10.3 0 0 4 .6 Oral mucosa: Keratosis ... 211 16.2 113 19.1 Leukoplakia , . . . .. . . 18 1.4 0 0 Tongue: Keratosis . Fissure . . Varicosities ____ 10 0.8 _ 79 6.0 _ 538 41.0 5 .8 36 6.1 77 13.0 Palate: Keratosis . 239 18.2 26 4.4 Gingiva: Inflammation Keratosis . . . 665 50.7 251 42.5 _ 129 9.9 8 1.3 Uvula: Inflammation __ . . 733 55.9 290 49.1 Velum: Inflammation 213 16.2 47 7.9 Note: Edentulous persons are included except for inflam m ation of the gingiva. tion appears m ost frequently after m iddle age (168) and is probably due to old age atrophy (169). It was observed th at of the white males who w ere less th a n 45 years of age 11.7 p ercen t had varicosities of th e tongue, as opposed to 71.0 percent for those 45 years of age or over; for sim ilar age groups th e nonw hite h ad only 6.2 an d 38.8 p er cent. T he num ber of white males affected for each of the two age groups was nearly twice th at which was observed for the respective nonwhite group, while the rate of increase for both groups with the advance in years was alm ost the same. I t is observed th a t for inflam m ation of the gingiva, uvula, and velum the w hite in all cases had a higher rate than the nonwhite. G enerally speaking, with the exception of keratosis of the oral mucosa, the non white presented a lower rate for all abnorm alities of the structures listed than the white. 114 A ttritio n T he air-borne dusts to which the foundry workers were exposed contained free silica, m ixed silicates, iron, and traces of organic sub stances. D uring talking, and either habitual or occasional m outh breathing, these dusts enter the oral cavity, and those with abrasive qualities m ay affect the teeth, resulting in attrition or the wearing aw ay of tooth structure. Table 44.-- N um ber and percent of m ales showing attrition of the teeth among workers in 16 ferrous foundries in Illinois according to age, com pared w ith steelworkers Age (years) Open-hearth1 and steel wire2 workers Foundry workers Total examined With attrition Number Percent Total examined With attrition Number Percent Total 530 Under 35 215 35-44____________ 117 45-54____________ 116 55 or over 82 70 13.2 1,668 329 19.7 9 4.2 676 18 2.7 13 111 397 46 11.6 18 15.5 296 84 28.4 30 36.6 299 181 60.5 1 Reference 64. 2 U npublished data. Note: Edentulous persons are excluded. In an effort to ascertain the extent th at air-borne dusts m ay have affected the foundry workers' teeth, a comparison was made of the percent of w orkers affected in this industry w ith sim ilar inform ation in other industries. Differences in the incidence of attrition for each group were noted. For this purpose, the data from a study conducted among open-hearth furnace (64) and steel wire workers (170) were com bined and are presented w ith data of the foundry w orkers in table 44. I t will be observed th a t 19.7 p ercen t of th e fo u n d ry w orkers have attritio n , as co m p ared to 13.2 p erce n t for th e o p en -h earth an d steel wire workers. F o r the foundry w orkers there is a rapid increase from 2.7 to 60.5 percent of the persons w ith attritio n in th e age groups from under 35 years to 55 years and over, while the com parison group increased from 4.2 percent to 36.6 p ercen t for th e sam e age groups. T he percentage of persons affected w ith attrition is less for the foundry workers in the group under 35 years of age and approxim ately the same in the age group 35 to 44, but there appears a m arked dif ference in the age groups of 45 and over when com pared to corre sponding ages of the open-hearth and steel wire workers. Among the 115 foundry w orkers, 12.9 percent m ore persons in ages 45 to 54 years and 23.9 percent m ore in the age group 55 years and over are affected with attrition. Since these absolute differences are statistically sig nificant, they suggest th a t extrinsic factors present in the foundry workers' environm ent m ay be responsible for this difference. F rom the foregoing, it is noted th a t attrition of the teeth w as expe rienced by more foundry workers than other industrial workers selected for comparison. T o determ ine the extent to which such extrinsic fac tors as abrasive air-borne dusts m ay contribute to the wearing away of the teeth of the foundry workers, a study was m ade of the different occupations where the dust concentrations were known to vary. For this purpose, the workers were divided into four occupational cate gories; nam ely, corem akers, molders, cleaners and finishers, and a miscellaneous group consisting of m aintenance and supervisory employees, laborers and others, and shakeout men. T he num ber and percent of persons w ith attrition and the num ber of years in their principal occupation are presented in table 45. Since no significant difference with regard to attrition was noted between the white and nonwhite groups who had the same num ber of years in the same occupation, these groups were com bined in com paring the different occupational categories. It is recognized th a t different individuals have varying degrees of hardness of tooth structure. How ever, it is reason- Table 45.-- N um ber and percent of m ales showing attrition of the teeth among workers in 16 ferrous foundries in Illinois according to years in principal occupation Years in principal occupation Total Coremaker Cleaning Miscel Molder and finishing laneous1 Number with attrition Total - 327 24 127 75 101 0 - 9 ______________ 99 5 18 26 50 10-19____________ 79 9 18 31 21 20 or over _ 149 10 91 18 30 Percent of all foundry workers Total, 19.6 12.6 27.4 24.7 0 - 9 _________ ____ 9 .3 5.7 7.8 12.3 10-19___________ 25.4 16.1 20.7 47.0 20 or over________ 51.9 21.3 62.8 66.7 1 Includes shakeout, m aintenance and supervisory, and laborer and other. Note: Edentulous persons are excluded. 116 14.2 9.3 20.6 44.1 able to assume that workers with varying degrees of tooth hardness w ere equally distributed in each occupational group. Also, a certain am ount of increase in attrition w ith age m ay be attributed to the natural function of m astication. Because of the close positive associa tion betw een age an d years in principal occupation, it is assum ed th a t differences shown in table 45 will take into account the age factor as well as the experience factor. It is observed th a t the total percentages of persons having attrition for th e four occupational groups increase as follows: C orem akers, 12.6 percent; m iscellaneous group, 14.2 p ercent; cleaners a n d finishers, 24.7 percent; and m olders 27.4 percent. W ith regard to the num ber of years in th e principal occupation, th ere is an increase in th e rate of persons having attrition for each of the four occupational categories, and it will be observed th a t this rate of increase differs for the different occupa tional groups. For the coremakers, for whose occupation the dust con centration was known to be th e lowest, th e incidence of attrition was found to be 5.7, 16.1, and 21.3 p ercen t for groups w ith 0-9, 10-19, and 20 years and over, respectively, in their principal occupation. On the other hand, for the cleaners and finishers and the molders, for whose occupations the dust concentration was found to be higher, a more rapid increase in the percent of persons affected with attrition was observed. T he corresponding experience group percentages for the cleaners an d finishers are 12.3, 47.0, and 66.7 percent; an d for the m olders, 7.8, 20.7, a n d 62.8 percent. F ig u re 23 g raphically show s th e increase in the percent of persons affected w ith attrition for the four stated occupational groups by num ber of years in such occupation. It will be observed that, for all the four groups exposed 0-9 years in their principal occupations, the differences in the percent of persons with attrition are relatively not great. For workers exposed between 10 an d 19 years, th e cleaners an d finishers show a m ark e d increase over the molders, coremakers, and m iscellaneous group in the percent of persons so affected. F or exposures of 20 years and over, the incidence among molders increases more rapidly than among the other groups and approxim ates that experienced by the cleaners and finishers; little change in incidence is noted for corem akers. I t is interesting to note th at the miscellaneous group of employees, who work for different intervals in various parts of the plant, where they are subject to both high and low dust concentrations, experience attri tion of a degree closely paralleling th at which was found for all occupa tional categories combined. Thus, it m ay be stated th at the abrasive dusts in the atmosphere, to which the foundry workers were exposed, accentuated the wearing away of tooth surfaces and th at the attrition varied directly w ith the concentration of the abrasive dust in the atm osphere and the duration of such exposure. T he upper and lower anterior teeth were m ost often affected, and in some cases as m uch as 117 Y EA R S IN O C C U PA T IO N *Includes shakeout, m aintenance and su p erv iso ry , lab orer and oth er. Note: Edentulous p erson s are excluded. F ig u r e 23.-- P e rc e n t of m ales show ing a ttritio n of th e te e th am ong w orkers in 16 ferrous foundries in Illinois according to years in principal occupations. (T o facilitate reading each set of 3 points has been joined by a straight line.) one-third to two-thirds of the clinical crown of both anterior and posterior te eth was involved. T h ere w as no evidence of an increase of sensitivity due to the loss of tooth structure. N o teeth were observed in w hich th e pulp was exposed as a result of attrition. As is shown in figure 24, secondary dentine form ation com pensates for the loss of tooth structure, thus preventing pulp exposure. Figure 24.-- Severe attrition and evidence of deposition of secondary dentine observed in a 53-year-old white m ale foundry worker whose principal occupation for 23 years was molder. Garlic-like B reath Sm all am ounts of tellurium are som etim es added to m olten iron. D uring the process some of the tellurium is volatilized into the atm osphere. Persons inhaling air containing a sufficiently high con centration of this elem ent for a reasonable length of tim e have been reported to present the following sym ptom s: garlic odor of the breath, dryness of the m outh, m etallic taste, somnolence, loss of appetite, garlic odor, and partial suppression of the sweat (171). In one of the plants studied it was noted th at 63.4 percent of the workers had a garlic-like odor of the breath. A consultation w ith the plant m anager revealed that, in special cases, tellurium was added to m olten iron; the last such occasion had been 30 days prior to the clinical study. Since tellurium was not being used at the tim e of the study, data relative to its atm ospheric concentration were not avail able. W ith the exception of garlic breath, sym ptom s som etim es associ ated w ith this exposure were not observed. 119 Summary of Medical Studies F ro m th e 16 ferrous foundries, em ploying ab o u t 2,000 persons 1,937 males were m edically examined. T he adequacy of the sample from the points of view of age distribu tion, years spent in foundry work, and occupational distribution was believed to be satisfactory. Of the group, 69 percent were white persons, and 31 percent, nonwhite. T he lim ited exam ination of the eyes and their functioning revealed no abnorm alities which could be attributed to the occupation. Skin disease, p ro b ab ly of o ccu p atio n al origin, w as p rese n t in 1.7 percent of the foundrymen. Significantly elevated blood pressure levels were related to increas ing degrees of pulm onary fibrosis. N either the cardiac nor renal findings were rem arkable in this study. P o sitiv e serological te sts for syphilis w ere found in 2.1 p erce n t of th e w hite an d 10.3 p ercen t of nonw hite foundrym en. For the entire group of workers studied, total leucocyte count, hematocrit, and erythrocyte sedim entation rate were not at variance with com parable industrial groups. T he erythrocyte counts and hem o globin estim ations appeared to be lower than those of open-hearth steelworkers. These latter observations did not appear to have an association w ith occupation. V ital capacity estim ations showed a correlation with age and no correlation w ith degree of pulm onary fibrosis. Reinfection type of pulm onary tuberculosis, considering both active and inactive to the degree that such was determ inable from the limited n atu re of th e m edical exam ination, w as found in 0.7 p ercen t of w hite w orkers, an d in 1.7 p erce n t of th e nonw hite w orkers. T h ese p ercentages appeared to be similar to those of other studies of adults of both sexes m ade recently in the area in which the present study was performed. Significant pulm onary fibrosis of occupational origin, as determ ined by roentgenogram and the historical and clinical data, was found in 9.2 p erce n t of th e foundrym en; in 7.7 p erce n t it w as ground glass tw o stage a n d in 1.5 p ercent, n o d u lar in type. Of th e instan ces of p u l m onary n o d u lar fibrosis, 1.3 p ercen t of all th e fo u n d ry m en w ere in stage one; 0.15 percent, in stage two; and 0.05 percent, in stage three. T o the lim ited degree th at the pulm onary effects of iron and its com pounds were evaluated, it was felt that they did not appear to play a significant role in this study. T he instances of nodular pulm onary fibrosis occurred with about equal frequency in the steel and gray iron foundrymen. In general, it required 14 or m ore years of exposure to develop nodular silicosis in the ferrous foundry industry. Sym ptom s w ere of m inor significance in the instances of nodular pulm onary fibrosis observed in this study. 120 N odular pulm onary fibrosis occurred predom inantly am ong the molders in the gray iron foundrym en group and among the cleaning and finishing workers in the steel foundrym en group. A lthough previous levels of dustiness in the foundry industry prob ably were of significance in the occurrence of pulm onary fibrosis as observed in this study, evidence is adduced to indicate th a t exposure in o th er d u sty trades, p rio r to th e w orker's e n try into fo u n d ry work, had very little if any bearing on such pulm onary fibrosis. Increasing degrees of pulm onary fibrosis were associated with increasing speed of erythrocyte sedim entation and with progressively increasing total leucocyte counts. No association existed between degrees of pulm onary fibrosis and erythrocyte count, hem atocrit values, hemoglobin estimation, m ean corpuscular volume, m ean cor puscular hemoglobin, and m ean corpuscular hemoglobin concentration. D ental status in term s of decayed, missing, and filled teeth of the white foundry workers was observed to be similar to th at of other industrial workers studied. 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