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FILE NAME: US Gypsum (USG) DATE: August 1933 DOC#: USG020 DOCUMENT DESCRIPTION: 1933 unpublished report on the physical condition of the health of 100 employees of USG in Oakville, NY Final Report upon the Physical Condition and the Health of 100 Employees in the U.S.Gypsum Plant at Oakville, New York, by the Saranac Laboratory, August 1933. The following report is submit ted on the study begun on June 19, 1933, of the dust hazard in the OakfieM plant of the U.S.Gypsum t * - - Co. >.!*-- A SURVEY OF THE PLANT was first made and our impressions were... ---------------- - . - - - .. fully discussed in the preliminary report of June 27, 1933. Briefly these observations yielded the following points which were regarded as significant: ; 't[ y The mine apparently offered no particular hazard ^ ------------------ ------ , n. I- -ill- r -f : r H i,, /.W -* /1?_-3-t - ' * as the ventilation was excellent, the operating methods' generated no great amount of dust and the rock and ore were not of a nature known to produce serious pulmonary '*v - damage. The portions of the plant devoted to crushing, calcining and grinding gypsum were quite dusty but owing . N; v -* 3 to the nature of the dust this was not considered hazard ous except in one particular. Certain grinding operations were done in Buhr stone mills. The stones themselves : being quartz contained high percentages of crystalline ' ' silica which is a well-recognized cause of pulmonary fi- ' brosis. Particular stress was laid upon the necessity k? \ of protecting the man or men who dress the buhr stones as thesee persons would be subjected to dangerous quaint ," ties of highly injurious dust. * / -The board and block plants offered no indication of a hazard. Likewise the paper mill, lime plant, power house and shops appeared to be free of danger from dust?\ The warehouse did not present such a favorable picture, as many of the operations of mixing and bagging sand plasters.involved exposures to considerable quantities of fine silica. The lack of any protection for the oper ators appeared to expose the workmen to grave hazard. The special operations to which exception was taken were the Bates Backer, 7/!12, and the mixing done by men on the second floor over this machine. DUST SAMPLING - Representative samples have been taken from various portlens of the plant and mine at the points where men might be exposed. The technique employed has been the standard procedure in the United States, using a Greenburg-Sraith inpinger apparatus for collection of sample's and counting particles in a Sedgewick-Rafter cell by light-field illumination at a magnification of 100. In addition counts of the same dust suspensions were made with two other methods of dark field illumination, one at a magnification of 100 and another at 00. By the use of the higher magnification and the dark field illumination smaller particles are visualised than can be de tected by the standard procedure. There fellows a tabulation of the variov.s counts: / c MINING Sample No.l June 19, 1933 Location: Operation: Time: l3t.Virest - 1st.South - 14 Rt.Main Sotith - Rt.Entry. Drilling in Gypsum First Hole Started 10;53 Finished 10:64 6 minutes Second Hole Started 11:15 Finished 11:30 15 minutes 5i-- ' Air Pressure: 40 lbs. Notes: Electric Drill. Drilled one hole. Started second at time of sample. 2 men mucking within ten feet. Roof 4 ft. Height of impinger 3 ft. 5 to 6 ft. from face. Place is pocketed not very rapid air circulation. Roof dripping - working place is wet. Counts: Number of particles (less than 10/x) per cu.ft.of air. Light field Dark " Plankton Dark M Dissecting 1,340,000 2,650,000 9,600,000 Remarks: The standard light field count is approximately 1,350,000 with a silica concentration which does not exceed 2%, Petrographic analysis of the gypsum shows aooroximately 75% CaSQA: 2 H2 O, 10% CaS04, and 15% CaCOg. I Sample Ho. 3 June 20, 1933 Location: Room 27 - 16 Rt. 3rd South - 14 Rt. Llain South Operation: Drilling in Gypsum Time: Started: 10:37 Finished: 10:52 15 minutes .1r> pressure:22 lbs. Notes: Electric drilling in gypsum using 1 1/4!l augur drill. Drilled 2 holes. Dead ended - air in from nearby room. No mucking. Roof 3 1/2 ft. Counts: Number of particles (less than lC|u) per cu.ft. of air. Light field Dark " Plankton Dark " ^issQQtlng ,1,645,000 2,650,000 5,530,000 Remarks: The- standard light field count is approximately 1,650,000 vdth a silica concentration which does not exceed 2/. Petrographic analysis of the gypsum 3hows approximately.75/ CaS0A : 2H20, 10/ CaSOa, and 15/ CaCOj The average standard light field count of Sample Ho.l and No.3 is approximately 1,500,000 mining San pie No,4 June 20, 1933 Location: lst.',7est --3rd South -14th Rt.JVlain South - 3rd Entry Operation: Drilling in Anhydrite Time: Started Finished 11:19 11:29 10 minutes Air Pressure: 22 to 32 lbs. Notes: Air machine - Auto, feed - 1" Drill. No mucking, dead end. Roof 3 '10". Distance from face 3 1/2*. Count3: Humber of particles (less than 10^a) per cu.ft.of air. Light field Dark " Plankton Dark " Dissecting 10,100,000 23,400,000 46,800,000 Remarks: The standard light field count is approximately 10,000,000 with a silica concentration which does not exceed Qb% silica at the maximum. MINING Sample No5 Location: June 20, 1933 1st .'Vest - 3rd South -14th Rt. Slain South - 3rd Entry Operati on : 'Drilling in anhydrite Time : Started: 11:34 Finished 11:44 I minutes Air Pressure: 32 to 22 lbs. Notes : Air machine - Auto.feed - 1" Drill. No mucking. dead end. Roof S'lC*. Back of drill and 9ft.from face. Oounts: Number of particles (less than 10ji) per cu.ft.of air. Light field Dark " Plankton Dark " Dissecting 11,300,000 24,550,000 78,500,000 Remarks : The standard light field count is approximately 11,300,000 with a silica concentration which &os3 not exceed 0.5$ silica at the maximum. The average standard light field count of Sample No 4 and No.5 i3 approximately 11,000,000 MINING Sample No.25 June 22, 1933 Location: 16 R 3rd S - 14 Rt.Main South. Next to Air Drill Operation: Drilling in the Roof. Time: -Started Finished 2:22 2:25 1/2 / 01 1/S minutes ' Air Pressure 35 lbs. Not e s : Flask held close to head of man operating air drill. Drilling in roof. Counts: Number of particles (less than 10ja) per cu.ft.of air. Light field Dark " Plankton Dark " Dissecting 1,930,000,000 3,900,000,000 4,610,000,000 Remarks: The standard light field count is approximately 2,000,000,000 with 45$ acid insoluble material. Petrographic analysis shows the material to be approximately 60$ limestone and 40$ clay. The average standard light field count of Sample No.2 and Sample No.25 is approximately 1,000,000,000 MINING Sample No. 24 Location^ Operation: Time Air Pressure: Notes : Counts : June 22, 1933 3rd North - 3rd South,14 Rt.Main South - In Passageway. Hauling Gypsum Started Finished 1 :37 1:52 15 minutes 36 to 44 lbs. Mine air - haulage way - near mining operations. Flask 5 1 above ground over track and close 5' to junction with other drift. Number of particles (less than 10/ x) per cu.ft.of air. Light field Dark " Plankton Dark " Dissecting 1,780,000 3,735,000 16,800,000 Remarks: The standard light field count is approximately 2,000,000 with a low silica concentration. HIKING SampIs No.26 Location: Operation: Time: Air Pressures Notes: Count3: June 22, 1933 At foot of #3 shaft. 75 ft. South Loading Started Finished 3:47 1/2 3 ;62 1/2 15 minutes 35 to 40 lbs. Flask 5* above ground near middle of passage way (25'wide) hoisting going on; empty cars being shifted past set-up. Moderate draft of air through passage. Number of particles (less than 10jx) per cu.ft.of air Light field Dark " Plankton Dark " dissecting 2,950,000 4,220,000 31,400,000 Remarks: The standard light field count is approximately 3,000,000 with a lo*v silica concentration. GYPSUM MILL OPERATIONS Sample No.6 June 20, 1933 Location: 'weighing Floor Operation Weighing and Crushing Time : Started Finished 1:38 1:58 20 minutes .-iir Pressure: 40 to 42 lhs. iiOoes: One car per chute (2 chutes) dumped every 40 sec. (300# per car) Sample taken 2 ft. back from corner of chute. Counts Number of particles(less than lOyu) per cu.ft.of Light field Dark " Plankton Dark " Dissecting 2,350,000 3,890,000 8,430,000 Rema rks : The standard light field count is approximately 2,500,000 with lov/ silica concentration. R.-.; GYPSUM KILL OPERATTIIOKS Sample Ko.7 Location: Operation : Tine : Air Pressure: Notes : Count s : June 20, 1933 Set-up next to top at elevator at conveyor belt (conveyor belt was carrying gypsum) Conveying and storage of crushed gypsum Started Finished 2:31 2/3 2:45 2/3 14 minutes 40 Its. Sample taken 5 ft. above floor. Sample taken 2 ft. above conveyor belt. Note: indov/s open and strong draft across floor. Number of particles (less than 10jo .) per cu.ft.of air. Light field Dark " Plankton ' Dark " Dissecting 4,280,000 7,680,000 14,500,000 Remarks : .The standard light field count is approximately 4,000,000 with lev/ silica concentration. RAYZ GYPSUM iv.ILL OPERATIONS Sample No.15 June 21, 1933 Location: Near hammer mill, elevator and conveyor in crushing plant. Operation: Hammer mill operation. Time: Started Finished 2:1V 1/2 2:27 1/2 10 minutes ..ir Pressure : 4C its. Notes: Crushing raw gypsx'm. Flask 5 ft. above floor; about 12 ft. from and level with point where conveyor empties into crusher. '.Vail 20 ft.away with 2 open windows; door open in each side wall. Moderate draft through room. Counts: Number of particles (less than lO^u) per cu.ft.of air Light field Dark " Plankton Dark " Dissecting 13,500,000 25,300,000 34,400,000 Remarks: The standard light field count is approximately 13,500,000 with low silica concentration. \ ;a l c ik in g ind grinding- c a lc in e d gtpsux Saraple No.29 June 23, 1933 Location: Between Calciners {Rotary Kiln) Operation : Calcining Time : Started Finished 10:07 1/2 10:11 1/2 04 10:12 1/2 10 15 1/2 03 Total:07 minutes Air Pressure: 40 Ihs. Fetes : Flask 5 1/2! high, S ' from each kiln 20* from furnace end of kiln. Set-up in passageway, 3 0 ? from open doors, moderate movement of air. Impinger disk moved down after 1st. run. Gonno 3 ; Number of particles (less than 10j j .) per cu.ft.of air Lirht field Dark " Plankton Dissecting 1,175,000 1,417,000 No count - bacteria noted. Remarks: Tha standard light field count is approximately 1,A 30,000 with lew silica concentration. i c CALCINING aND GRINDING CALCINED GYPSUM Sample Ho. 30 Location : Operation : Time : Air fressure Notes : Counts : June 23, 1933 Next to Hummer Screens Hummer Screens Started: Pir.ishe d : 10-54 1/4 11? 00 1/4 06 minutes 40 lbs. Flask 4 1/2* high, 1 ' from machines - 2 operating. Set-up in passageway next to screens. Moderate draft of air past screen conveyors, past flask and out between screens. Flask broken - no count. I i CALCINING AND GRINDING CALCINED GYPSUM Sample No. 31 June 23, 1933 Location: Between Ball Mills Operation: Ball Mill Grinding Time : Started: Finished 11:18 11:27 09 minutes Air Pressure : 40 Its. Notes: Flask 5 high, 10* from each mill - 2 0 ' from end wall having one open window. Moderate movement of air. Floor covered with fine dust small amount leaking from one mill. Counts: Not counted - bacteria noted. OwOiTlF.''^. ^mnv'TT 'vffiifc'JR-TiT1..pyX^iT*T7LI^ Sample No. 14 June 21, 1933 location: Among Buhr Stone Grinders Operation: Buhr Stone Grinding Time: Started1 Finished: 1:36 1:46 10 minutes Air Press u r e : 40 Its. Notes: Flask set in center of room among Buhr stone grinders; 16 operating and grinding. Flask about 4 1/2 above floor; about 3 ft. above and 3 ft. from opening of grinder. Moderate draft of air across room. G ount s : Number of particles (less than 10y x ) per cu.ft.of air Lirht field Dark " Plankton Dark " Dissecting 2,432,000 4,060,000 10,720,000 Remarks : The standard light field count is approximately 2,500,000 with slightly increased silica con centration - not to exceed 5% BLOCK PLAUT Sample No. 27 June 23, 1933 Location: Block Plant - Over Accelerator Grinder Operati on: Grinding accelerator. Time : Started Finished 9:19 1/6 9:25 1/6 6 minutes Air Pressure: 40 Lbs. Notes : Flask 3 { above and 4* over from chute where accelerator dust is being shaken on moving belt covered with gypsum. Set-u.p 10* from wall (windows closed); slight current of air tends to carry dust away from flask. Counts: Number of particles (less than lO^i) per cu.ft.of air. Remar ics : Light field Dark " Plankton Dark " Dissecting 15.550.000 23.750.000 36,000,000 The standard light field count is appron iU'C:ly 15,500,000 with a ,cw silica concentrati.. a. Samle lo. 28 Location: Operation: rn> ^ .L .>...1V/ "n^ - - ,-i Mo tos: Counts: Remarks: 1 O ''T. 1 y -k-w v> 0 Block Plant - Band Llixer Hand .lining Operation. (This operation is more dusty than the machine operation.} Started: Finished: 9:38 1/2 9:43 1/2 teO .iXxiwl js Flask 5 1/2* high, 2* from bucket and chute (gypsum and water is fed into bucket 3 hoi* thru chute; rotating disk nines gypsum). Fixer in middle of room IC O 1 wide, door in each side wall open. Fair movement of air from V/. Operator stands over miner, say 20/ of time; a mix every 4 min. .lumber of particles (less than 10y x ) per cu.ft.of air. Light field Bark !l Dark it (Plankton) Dissecting 4.870.000 6.425.000 20,000,000 Standard 1ight fieId covmfc is approximately 5,000,000 with a low silica concentration. <r Sample No 13 Location: Operation; Time: Air Pressure: Notes: Counts: rV . June 21, 1933 Above accelerator grinder in board plant. Guiding accelerator. Started: 4.04 1/2 Finished:4.14 1/2 .10 minutes 40 lbs. Flask 5 1/2 ft. above floor and grinder; 5 ft. over from grinder. Not so well ventilated; nearest window about 30 ft. dumoer of particles (less than lOya) per cu.ft.of air... Light Dark Dark "ield Plankton ZDf-r n 3 c Jcf-'l' 12.430.000 20.500.000 05.100.000 Rena: The standard light field count is approximately 12,500,000 with a low silica concentration. V 3 CARD PLANT Sample Ho. 23 June 22, 1233 Location: kiddle of Board Plant. Operation: General Air (near discharge from kiln) Time : Started: 11:20 Finished:11:40 .20 minutes Air Pressure: 40 Tos. Ilotes : Flask set at H end of kiln of #2 hoard machine; 5 1/4 ft. above floor, in Centex* of room (300' xl0Q !). '.Vindows open on 2 side, doors on Y/ side (100* wide). Counts : Humber of particles (less than 10yU.) per cu.ft. of air. Light field Dark " Plankton Dark " Dissecting 503,000 800,000 3,450,000 Remarks : 'The standard light field count is approximately 500,000, with a low silica concentration. \ WAREHOUSE Sample Ho. 3. J'one 20, 1933 Location: Set-up next to A 6 machine packing cement-plaster. Level v/ith operator^ shoulders and close to him. Operation: Packing gypsum plaster in paper bags on machine provided v/ith exhaust system. Time: Started: 3:15 Finished: 3:19 2/3 .04 2/d minutes Air Pressure: 40 lbs. Notes: Llachine / 6 ; This machine has exhaust system. Fan over doorway 15 it. from machine v/as operating, blowing air from outside, across operator, toward machine. Contains gypsum, hJ seisel and retarder. Ho sanded plaster being made at present time. G ounts: Humber of particles (less than 10 u) per cu.ft. of air: * y Light field Dark " Plankton Dark " Dissecting 11,250,000 10,950,000 31,500,000 Remarks: The standard light field count is approximately 11,500,000 v/ith a low silica concentration. V C ' '.7ARSH0U33 Sample No. 10. June 20, 1933 Location: Set-up next to 776 machine. jute hags v;ith gypsum. Packing Operation Packing gypsum plaster in jute bags on machine provided v/ith exhaust system. Time: Started: 4:33 Finished: 4:45 10 minutes m r X w u*O Lta.\j * 40 lbs. ( X. . Notes: Counts: Llachine No. 6 has exhaust system. Strong i wind blowing outside and through hail past machine. No sanded plaster being made at present time Number of air: particles (less than 10 u )oer cu.ft.of Light field i 6,350,000 Dark " ? lankt on 9,500,000 Dark " Dissecting 53,200,000 Remarks; The standard light field count is approximately 6,500,000 wi t h a lev/ silica concentration. 1 Sample No. 9 'WAREHOUSE June 20, 1933 Location: Set-up next to # 7 machine packing wood-fiber plaster. Close to oper ator as for sample #8. Operation: Packing wood-fiber plaster in paper bags on machine provided with e;diaust system. Time : Started: 3:53 Finished: 5:43 10 minutes Air Pressure: 40 lbs. Notes : Fan over doorway 15 ft. from machine was operating, blowing air from out side across operator toward machine. Contains gypsum, wood fiber, retarder and small amount of lime (25# per ten). No sanded plaster being made at present t ime. i C ounts: Number of 1S991 particles (less than : per cu. ft. of air: Light field Dark " Plankton Dark " Dissecting 15,150,000 29,500,000 80,400,000 Remarks: The standard light field count is approximately 15,000,000 with a low silica concentration. V/ARSIiOUSL Sample No. 16. June 21, 1933 Location: Next to #9 Mixer. Cement-Plaster. Operation: Mixing gypsum plaster. Time: Started: 2:50 1/2 Finished: 2:54 3/4 .04 1/4 minutes Air Pressure: 40 lbs. No fees : C omit s : Flask 2 ft. over and 1 ft. above opening v/here mixer is fed; flask is 5 1/2 ft. above floor, 20 ft. from side vfall and open v/indov/3. On West side of building. Mixer being fed gypsum, seisel, retarder. Liquid in flask foamed considerably lim iting duration of collection. No air protection on machine. Number of m b b b particles (less than 10j x ) per cu. ft. of air: Light field ! Dark " Plankton Dark " Dissecting 15,900,000 35,700,000 55,625,000 Remarks : The standard light field count i3 approximately 15,000,000 with a lovf 3ilica concentration. X $ WAREHOUSE Sample Wo. 20 June 22, 1933 Location: Operation: Tims: Air Pressure; Notes: Count3: Remarks: Went to ;fl2 L'achine packing sanded plaster. Packing Sanded plaster. Started: 9: 27 1/2 Finished:9: 29 1/2 2 minutes 40 lbs. Wo exhaust on machine. Flask 1 ft. from operator's head; at shoulder level. Oper ator 10 ft. from .vail and open door. Number of EMBBa particles (less than 10 /a) per cu. ft. of air: Light field Dark " Plankton Dark " Dissecting 23,175,000 74,900,000 48,300,000 The standard light field count (average for samples 17 and 20) is approximately 30,500,000 with a low silica concentration. WAREHOUSE o H <! Sai2Ple June 21, 1933 Location: Next to Tf7 Mixer - 7/ood fiber Operation: Mixing wood fiber plaster Tine: Started: 3:33 Finished: 3:37 1/3 4 1/3 minutes Air Pressure: 40 lbs. Notes: Flask 1 i/2 ft. above, 2 ft. over from feed opening in machine; 5 1/2 ft. above floor; 20 ft. from side wall and open windows; next to L7, Part of time flask held close to feed opening, where operator stands. No protection on machine. Counts: Number of EfSffigi particles (less than 10 ju) per cu. ft. of air: Light field 32,400,000 Dark n Plankton 74,300,000 Dark " Dissecting 125,000,000 Renarks: The standard light field count (average for samples 17 and 20) is approximately 30,500,000 with a low silica concentration. .iAR: Sample No. 19 Juno 22, 1933 Location: Next to #12 Machine packing sanded plaster. Operation: Packing sanded plaster. Machine not pro vided with exhaust system. Time: Started Finished 9:19 1/2 9:21 1/4 1 3/4 minutes (flask foamed) Air Pressure: 40 lbs. Notes: No exhaust on machine. Flask 1 ft. from operator's head; at shoulder level. Oper ator 10 ft. from wall and open door. G ounts: Number of BMMm b particles (less than lOyu) per cu. ft. of air: Light field Dark " Plankton Dark " Dissecting 44,200,000 66,300,000 73,000,000 Remarks: The standard light field count is approximately 44,000,000 v/ith~an appreciable concentration of silica. Note: See analysis of sand under Sand Plant. 'The formula for this piaster contains 6007# of coarse sand ana 700# of fine sand per 1927# of mix. iVAREEOUS: Sample No. 22 June 22, 1933 Location: Next to #12 Mixer - Sanded Plaster Operation: Mixing sanded plaster Time: Started: 9:50 l/2 Finished; 9:52 1/2 2 minutes Air Pressure: 40 lbs. Notes : Same as #21 except flask held 5 or 5 ft. from machine in different positions. Counts: Number of -- particles (less than 10 yu) per cu. ft. of air: Light field 146,000,000 Dark " Plankton 253,000,000 Dark n Dissecting 3,318,000,000 Remarks: The standard light field count i3 approximately 146,000,000 v/ith a very appreciable concentration of silica. Note: A sample taken directly opposite the sand discharge chute showed a count of 11,000,000,000. See analysis of sand `under sand plant. The formula for this plaster contains 600# coarse sand and 700# of fine sand per 1227# of mix. ( bannie >o 21 Location; Operation: Time : Air Pressure: Rotes : Counts : C \ Remarks: V;.-.R3::0U33 June 22, 1933 I'lext to # 12 Fixer - Sanded Plaster mixing Sanded Plaster. Start: Finish 9:41 9:42 1 minute (Foam over) 40 lbs. Flask held over feed opening where operator stands 1 ft. above opening; next to sand chute, ball a nd 3 open windows 12 feet away. Some circulation of air near machine but not vary good. number of particles (less than 10ya) per cubic ft. of air: / Light field J->s.vk " Plankton Dark M Dissecti: 1 1 ,2 2 0 ,000,000 24,700,IOC,000 9,500,000,000 -he standard light field count is approximately 11,000,000,000 with a very appreciable concen tration of silica, : Rote: This sample was taken directly opposite Ul-V/ sand dischar ge chute and represents the hi ~^est possible exposure at this location. See analysis of sand under sim d plant. The formula for this plaster contains 600# coa rse sand and 700.- fine sand per 1927-if of mix. C I \ c*a v n PT "fT' kjUIUp j.c liO* je .OTini uo ok,j Ji.cViO-^ Location; Furnace Room - Sand Drier Plant Operation; Furnace Room Tims; Started - 10;22 Finished- 10;35 lu nxnut o s Lir Freecure: 40 IDs. _ ^ClwIz set 7* fr ci door c; 1/2 1 ato v/all 12 * fro:lli fu: air in front cf Book doors cod cur rei V. C cunt s : Numder of pa rtic 1.s> of cS*i w ;han lOya) p< 7 A -r-V~ Dark Dark field Plankton " Dissecting 2.960.000 8.730.000 26,500,000 cf H* Remarks : File standard light field count is approximately 3,000,000. Chemical analysis of the coarse sand is as follows : Loss on ignition Total SiCo Ligi P-0-, Ti Go Fe gOj Gei. 0 lug 0 27.21 32.13 5.70 1.80 OT 1 O "Q ~ w a7. wo Free Si0o (ns quarta) determined chemically .~ one/ O. W **/ ^ Petrographic analysis discloses this sand to j~* rssi *I - u- y u- rO> licite a n d 25p free quarts. > \ 3nHD In'dii:T Le Ilo. 11 June 21, 19 Location ; Ope ra bio n : Time: Hear Roller crusher sand plant. Roller crusher room Started; 9:55 5/4 Finished: 9:60 3/4 ft r* ] >-.* c' Air Pressure- : 40 lbs. ITotes : Counts : Flask set 12 ft. from ci'-usher, 15 ft. from passage, 5 l/2 ft. above floor, in path at air stream from crusher out thru door. Rote: First sample was discarded "because 25 cc. liquid carried over. Another sample also taken. See 11A. Humber of particles (less than 10 u ) per cu. ft. of air: ' Light field 227,000,000 Dark " Plankton 292,000,000 Dark " Dissecting 2,500,000,000 The average count (standard light field) for sar.ples 11 and 11. , is approximately 237,000,000. Chemical analysis of the fine sand is as follows : Loss or. ignition Si Oo (silica) .1I0O3 ,? oOc,7'iOo FeoOg CaO " lugO 12.96 59.21 7.53 2.00 11.57 4.61 Free silica (as quartz) determined chemic h i y IS Petrographic unalp sis discloses this sand to be 50/ calcite ar.u 50/ free quartz. SAND PLANT .3 No. liA June 22, Location: Operation: Line-: Air Pressure: Notes: Counts: Remarks: Near roller crusher sand plant. Roller crusher room. Started 10:13 7 inishea 10:16 1/4 6 1/4 minutes. 40 lbs. 12 ft. from crusher, 3 ft. from door in path of air stream from crusher out through door. Numbor of particles (less than 10 u) por cu. ft. of air: Light field Dark " Plankton Dark " Dissecting 246,000,000 373,000,000 3,330,000,000 The average count (standard light field) fo: samples 11 and 11A is approximately 237,000 See Sample 11 for Chemical analysis. LIcCZLIuiIZlOUo OPERATIONS Sample No. 13 Juno 21, 193 Location: Operation: Lime; Air Pressure: Notes: Gaunts: Remarks: Next to man chipping Buhr stones Bulir stone trimming Started Finished 1:47 3/4 1:57 3/4 1 0 minutes 40 Iho. Flask set 3 1/2 ft. above floor; 1 1/2 ft. above and 2 ft. over from chipping hammer. Fan In wall IS ft. away drives current of air paso man aid cut windows 1 2 ft. away. Air-operated chipping hammer. Lian brushes off Buhr stones occasionally (every 2 min. or so) raising some dust. Number of particles (less than 1C /a) per cu. ft. of air: ' Light field Dark " Plankton Dark " Dissecting '5,320,000 11,950,000 18,400,000 The standard light field count i3 approximately 5,500,000 and the dust is practically pure silica. SUKI/kRx CF ANAL Y S E S OF DUST FROM GYPSUM FLAUT July 11, 1933 Percentage of Acid Insoluble Material Over T --1o ! 7Mr. *1 7 tt ft it *4* tt Gypsum Dust (for dusting animals) Ruhr Stone A s h or Roof Rock White Dark Grey 45.3$ 2.9$ 2 .0$ .0 $ 96.8$ 0 .0 $ 53.2$ 40.7$ GO DISCUSSION OF THE CHARACTER OF THE DUST AND ITS CONCENTRATION IN VARIOUS PORTIONS OF THE PLANT Obviously the proof of the development of silicosis or any other form of pneumonokoniosis must rest upon the presence in the industrial atmosphere of a sufficient quantity of silica particles or other dusts known to produce permanent injury to the lungs in such a state of fineness that they can be inhaled. The foregoing tables report in detail the results of dust sampling in representative locations throughout the plant and in addition there are appended, in appropiate places, analyses of the various types of material encountered. MINING. In the mining operations men are engaged in work upon three prinicipal types of rock, of which gypsum constitutes the greatest quantity. Chemical analysis of representative samples of gypsum shows that the total acid insoluble material varies from a trace to about 2 0 $. Petrographic analysis of this rock indicates that it contains approximately 75.0$ gypsum (CaS0 4 2 H2 0 ), 10.0$ anhydrite (CaS0 4 ), and 15.0$ calcite (CaCOg). fortunately there is not enough silica present in the native gypsum to constitute a hazard unless the concentrations of the total particles in the air are In excess of 250,000,000 particles per cubic foot. The actual dust concentration produced by drilling gypsum rock is less than 2 ,0 0 0 , 0 0 0 particles per cubic foot of air. Previous studies have failed to indicate that there is any hazard associated with calcium carbonate dust. Consequently it is is evident that there is nothing associated with the mining of ordinary gypsum which could be considered responsible for the production of silicosis. The second most important rock encountered underground is "'termed anhydrite and represents a native anhydrous calcium sulphate. ....... , ... --:'s' ...vv;, This* material shows from a trace to 0.5$ acid insoluble material. Since this rock is harder than gypsum an air operated percussion drill is required in the drilling operation and higher dust counts result. Average counts obtained during this operation showed 11,000,000 parti cles per cubic foot of air. Since the silica content of this rock is negligible, the dust produced in drilling it can not be regarded as capable of producing silicosis until concentrations of nearly 1 ,0 0 0 ,0 0 0 , 0 0 0 particles per cubic foot of air are created. The third and least extensive rock work undertaken under ground involves the removal of roof rock from the haulage ways. This roof rock is called ash and shows, on chemical analysis, from 41*0$ to 58.0$ of acid insoluble material. Petrographic analysis of this material indicates that it is an argillaceous limestone containing about 60$ calcite and 40$ clay. Clay contains aluminum silicate and therefore it can not be said that drilling the roof rock presents no dust hazard since certain silicates are known to produce pulmonary fibrosis. The operation of removing this roof rock from the haulage ways is performed with a jack hammer drill and the dust concentrations produced are very large. A count made near the head of an operator during a typical operation disclosed 1,930,000,000 particles per cubic foot of air. Obviously, this work is theoretically the most hazardous from the pneumonokoniosis standpoint of all the tasks per formed underground, and yet it can not be regarded as a serious hazard for several reasons. The work is not very extensive, it is intermittent in character, it involves only a few workmen, and the dust produced is not free silica but contains less than 40$ aluminum silicate. 37 Dust samples secured in the haulage ways near the mining /territory and near the loading shaft indicate that the amount of dust suspended in the general mine air is not excessive. RAW GYPSUM PLANT. Men engaged in this portion of the plant"' are exposed only to the dust of raw gypsum. Samples were taken on the , weighing floor, over the conveyors on the upper floor, and near the hammer mill. These samples were all taken during regular operations ' and the counts obtained indicate that there is not an excessive quantity of dust present throughout the greater part of this plant. Near the hammer mill the concentration was found to he 13,500,000 particles per ^ i.!cubic foot. This amount of gypsum dust is probably not dangerous, tout - - -/ it is advisatole to install equipment which will reduce the concentration .-- Ui. to less than 1 0 ,0 0 0 , 0 0 0 per cub ic foot. CALCINING AND GRINDING PLANT. In general the dust created in this plant is calcined gypsum. Chemical analysis of this dust shows that the acid insoluble material does not, exceed 2*0%. Petrographic .*1 analysis discloses approximately 70.0$ hemihydrate (CaS04 l/2 H20),5$ dead burned gypsum, 15.0$ calcite (CaC0 3 ), and 10$ anhydrite (CaS0 4 ). There are two sources from v/hich a siliceous contamination may occur in this plant, namely: the refractory material lining the kiln and the buhr stones used in one portion of the grinding operation. Neither of these sources of silica can be regarded as creating a real hazard for the following reasons: both the refractory material and the buhr stones are well enclosed, the actual amount of siliceous contamination added to the gypsum is very small (less than 1 .0 $), and the dust con- '-irS centrations arcund these operations is not excessive. Samples taken "between the calciners and over the buhr stone mills during normal ^operation show less than 1,500,000 and 2,500,000 particles per cubic foot of air respectively. Samples were also taken near the hammer screens and near the ball mills but due to bacterial contamination it will be necessary to obtain new samples from these locations. One individual operation, that of trimming the buhr stones, will be con sidered later. BLOCK PLANT. The dust created in the block plant is largely calcined gypsum. A small amount of wood fiber is also suspended in the air but this is not regarded as significant. .A sample recovered near the head of an operator using a hand mixer showed less than 5 ,0 0 0 , 0 0 0 parti cles per cubic foot of air. This concentration is low and would be permissable under any conditions. The grinding of accelerator (gypsum /blocks) produces concentrations of approximately 15,500,000 particles per cubic foot of air and though the dust is not considered hazardous, equipment should be provided which will reduce this concentration to less than 1 0 ,0 0 0 , 0 0 0 particles per cubic foob of air. BOARD PLANT. The dust created in the board plant is identical with that produced in the block plant and consists almost entirely of gypsum, A sample taken near the center of the plant shows only about 500,000 particles per cubic foot of air. This concentration is lower than that found on most city streets. The grinding of accelerator (gypsum blocks) produces concentrations of approximately 12,500,000 particles per cubic foot of air. This operation might be improved to reduce the concentration of dust, though it is not hazardous in either composition or quantity. At the southern end of the board plant is a , 'v^ machine for polishing veneered boards. Samples were not obtained near tiie operator of this machine, hut it was noted that no sand, flint, or quartz papers are used in this process, ^loicite paper is being used at the present time and its continued use is recommended. Research in this laboratory has shown aloxite to be relatively incapable of produc ing fibrosis, while the introduction of silica abrasives would create a very significant h a z a r d ! ^ WAREHOUSE.' There are a great variety of dusts present in the air of the warehouse. The largest single constituent of ghese various dusts is calcined gypsum; the second largest, is a fine sand. Chemical analysis of the fine sand shows that it contains 59$ to 60$ silica, and that 52.0$ of the sand is free quartz. Petrographic analysis discloses this sand to be approximately 50.0$ calcite and 50.0$ free quartz. Other constituents present in the air borne dust are, coarse sand, wood fiber, jute fiber, and organic materials used in the re tarder. Occasionally pure quartz sand, asbestos, and talc are used in plasters ard. a certain amount of dust from these materials must enter the atmosphere. The coarse sand shows 32.0$ silica on chemical analysis and 26.0$ of the sand exists as quartz. Petrographic analysis discloses this coarse sand to be 75.0$ calcite and 25.0$ free quartz. Dust collected from the rafters -over the #12 mixer at the southern end of the warehouse shows about 45.0$ acid insoluble' material. Similar dust from over #7 mixer shOY/s 3.0$ acid insoluble material, while the dust above #4 mixer shows only 2.0$ acid insoluble material. The largest part of the sanded plasters are made at the #12 machine. Sand ed plaster may contain as much as 65.0$ sand and since the sand contains from 25.0$ to 50.0$ quartz, the dust in the air may contain from 16.0$ to 33.0$ quartz. Obviously; the dust created in the making of sanded ' :-v.* plaster must be regarded as hazardous but this hazard appears to be fairly well localized to the # 1 2 machine. Samples obtained during the packing of ordinary cement plaster in both paper and jute bags on machines provided with exhaust ventilation showed from 6 ,0 0 0 , 0 0 0 to 1 1 ,0 0 0 , 0 0 0 particles per cubic foot of air. Another sample taken near the same machines during the packing of wood fiber plaster 3 howed 15,000,000 particles per cubic foot of air. These concentrations represent about the highest permiss ible counts and it would appear advisable to improve the exhaust system so that not more than 1 0 ,0 0 0 , 0 0 0 particles per cubic foot of air reach ed the head of the operator. In general, however, the packing of gypsum or wood fiber plaster on the machines protected with exhaust ventilation can not be considered hazardous. Samples taken on the second floor of the warehouse during the mixing of ordinary gypsum plaster or wood fiber plaster showed counts from 16,000,000 to 32,000,000 particles per cubic foot of air. Though the dust created in this operation does not contain significant quantities of silica, the concentrations are two or three times greater than the usual standards permit. Samples secured near the #12 Bates Packer (which has no exhaust system) during the packing of sanded plaster showed from 28.000. 000 to 44,000,000 particles per cubic foot of air. Since as much as one third of this dust can be pure quartz, it is obvious that men packing sanded plaster breath an atmosphere containing from 5.000. 000 to 15,000,000 quartz particles per cubic foot of air. This is considered to be a definitely hazardous concentration of harmful dust. The concentration of quartz particles per cubic foot of air 41 ought''never to exceed 5,000,000 and even this number may not be safe. For this reason it is urgently recommended that the operations involved in the manufacture of sanded plasters be given special consideration. A sample taken near the #12 mixer during the mixing of sanded plaster showed 146,000,000 particles per cubic foot of air. This concentration is excessive and hazardous and should be reduced to within 1 0 ,0 0 0 , 0 0 0 particles. A sample recovered near the point where fine sand is delivered to the mixer showed more than 1 1 ,0 0 0 ,0 0 0 , 0 0 0 particles suspended in a cubic foot of air. The mixing and packing of sanded plasters should be done in a section of the warehouse which is separately enclosed and special equipment should be installed to reduce the amount of dust suspended in the air to the minimum. SAND PLANT. The dust created in the sand plant is all produced by' the processing of the sands whose analysis have been given in the section dealing with the warehouse. The silica content varies from 32.0$ t o '60.0$ and the amount of free quartz varies from 26.0$ to 52.0$. A sample taken in front of the furnace showed approximately 3,000,000 particles per cubic foot of air. Though the dust is definitely dangerous, the concentration is not high and the hazard can not be very great in this position which the operator of the sand plant occupies a considerable portion of his time. A sample taken in the center of the roller crusher room showed the excessive concentration of 2 2 7 ,0 0 0 , 0 0 0 particles per cubic foot of air. Every effort should be made to keep the amount of dust in the air of this plant to a minimum which should never exceed 1 0 ,0 0 0 , 0 0 0 particles per cubic foot for in these con centrations this dust is dangerous BUHR STOGIE TRIMMING- Chemical analysis of the huhr stones has shown that they contain 97.0$ acid insoluble material and petro graphic analysis indicates that the material is practically pure normal quartz. A sample obtained near the head of the man engaged in trimming these stones with an air hammer showed 6,500,000 particles per cubic foot of air. This concentration is near the maximum per missible for pure quartz dust and is to be regarded as hazardous. It would appear advisable to move this operation to a separate room or to equip the operator with special exhaust ventilation. It is recommended that the following men be required to wear special respirators until such time as the dust concentrations in which they are working are reduced to within the recommended limits. 1. Miners drilling roof rock or ash. 2. Men mixing, packing, or carting sanded plasters in the warehouse. 3. All employees in the sand plant. 4. Men trimming buhr stones. By the methods employed it would appear that men are being exposed to excessive concentrations of dust. Since it is known that severe pulmonary damage is produced by silica, and if it is assumed that gypsum or calcium sulphate is relatively harmless it becomes essential to ascertain the relative proportions of these two sub stances in the atmospheric dust of this plant. It was assumed that this could be accomplished by making a preliminary count of the total dust particles in the air samples, then dissolving the calcium sulphate by treatment with acid and again counting the remaining silica particles which would not be attacked by acid. For technical reasons this procedure has proven unsatisfactory and it is deemed advisable to make a special study of this problem in another visit to the plant which will be made in the immediate future. It is proposed to employ an Owens-Jet Dust Counting Apparatus which will permit the collection of dust samples on cover glasses in such form that by direct microscopic examination the relationship of various particles can be observed and their petrographic characteristics can be determ ined. By the use of this apparatus it will be possible to determine not only the relative proportions of gypsum and silica in the atmos pheric dust but to learn whether the gypsum may not have been respons ible for the formation of aggregates of silica particles too large to be inhaled. The subsequent sections dealing with the condition of the workmen will disclose there is no demonstrable silicosis among them, and some explanation is necessary in view of the high concentra-tions of silica to which they have been exposed. PHYSICAL EXAMINATIONS - were made on 101 men employed for maximum periods in various portions of the plant. With two exceptions there was no evidence of disease of the lungs and in the two cases the condition was apparently not particularly serious. One man, Bert Werth, had been employed for 10 years in the block plant. He had a lateral curvature of the spine and a few changes in breath sounds with rales in the top of his left lung. His x-ray picture showed changes which could be interpreted as healed tuberculosis. Another man, Arthur Monette, was employed for nine years as a mason and brick layer. While he worked in all departments he spent most of his time in the power plant furnace and repairing the calciners. "Squeaks," both expiratory and inspiratory, suggestive of asthma, were discovered on two separate examinations. His x-ray picture showed a third degree of interstitial fibrosis but none of the hodulation characteristic of fully developed silicosis. Otherwise the physical examinationscf the chests in these men were quite negative. In 76 of the 101 cases cloudiness of the sinuses in the head were noted on transIllumination. In the absence of a definite history of sinus disease and without a thorough x-ray study of this condition a definite diagnosis of sinusitis could not be made. An equally high incidence of this condition has been observed in other dusty occupations. Two cases of heart disease and one of hyperthyroidism were discovered but neither of these could in any way be caused by inhalation of dust. In addition there were numerous cases with bad teeth, tonsils and nasal conditions which were reported to the men thru Mr. Daniels with the recommendation that they be given proper medical or dental attention. ROENTGENOLOGICAL EXAMINATION showed some evidence of abnormality in the lungs of 8 8 of the group of 1 0 1 , but in none were the changes very pronounced. No case could be diagnosed as silicotic. 45 The changes observed could not be correlated with the type or dura tion of occupational exposure. For purposes of classification the men were grouped according to the theoretical hazard of their occupation as follows: Table I. Occupation Number in Group Buhr Stone Dressers ...................... 2 Warehouse only........................... 6 Warehouse plus Other Departments.......... 9 Board P l a n t ............................. 19 Miscellaneous Occupations with Occasional Y/ork in Warehouse. . . . . . . 13 Miscellaneous Occupations with No Warehouse W o r k ..................... 19 Block P l a n t ......... 10 Mining O n l y ............................. 22 Laboratory Tester ....................... 1 Two main types of change, which might be due to dust, were ob served in the roentgenograms, (1 ) an increase in prominence of the normal linear shadows of the lung and (2 ) a diffuse haziness throughout the central portions of the lung fields. In the table following, the first change is designated as MFM and the second as "PM . The appended numerals indicate the intensity of these changes. Their significance will be discussed below. Table II. Summary of Roentgenological Findings Occupation No.in Group Miners 22 Block Plant Only 10 Miscellaneous with Occasional Ware- Pneumonokoniosis Tuberculosis 0 Pi Po P3 F t Fg F3 Healed Healed Childhood Adult ------------------- -------------------- -- 1 10 0 0 8 3 0 3 2 1300 060 1 .0 ..vtSvU'i ^ .. Table II. (Continued) Pneumonokonio sIs No.In 0 P, P,, P F, P P Occupation________ Group________ J Board Plant Only 19 Warehouse Only 6 Y/arehouse plus some work else where 9 Miscellaneous Occu pation with no Warehouse 19 Buhr Stone Dressing 2 Laboratory 1 52 2 0 8 2 0 21 0021 0 2 1 0 0 2 40 1 1 0 0 8 90 0000 02 0 01 00000 Tuberculosis Healed Healed Childhood Adult 4 1 1 0 3 0 3 0 1 1 0 0 On analysing these findings it appears that the "P" classification indicating a diffuse type of interstitial (?) reaction occurs most frequently in men exposed to pure gypsum dust. The presence of this type of reaction in the different occupational groups is summarized as follows: Table III Mining O n l y ............... . ................. 45$ Block Plant Only. ................ ......... . . 30$ Miscellaneous Occupations with Occasional Work in Warehouse..................... 23$ Board P l a n t ................................... 17$ Warehouse Only............................. 16$ Warehouse with Miscellaneous Occupations Elsewhere. ................................. 1 1 $ Miscellaneous occupations with no Y/arehouse Exposure .................................... 5$ Buhr Stone Dressing ............................ 0 The significance of this change has not been definitely ascertained for lack of autopsy material upon which to base an inter- -. pretation. Individuals do not always show a degree of reaction corresponding to the duration of their employment, but among the group of miners 38$ of those employed for 9 to 12 years show it while after mining from 13 to 25 years 55$ of the men have x-ray changes of this type. In the block plant group the corresponding percentages for the same employment periods were 20 and 40$ re spectively, while in the ticcasional Warehouse Employment Group" none showed it under 13 years of exposure. In two miners exposed for 9 and 21 years respectively this change was complicated by some emphysema. For these reasons we are inclined to associate this change with an exposure to gypsum dust, but we have no clear under standing of the underlying pathological condition. The other type of roentgenological change encountered which is labeled "F" consists of an accentuation of the linear shadoY/s cast by the bronchi and blood vessels. This change could not be correlated with the type of dust to which the men in the various groups were exposed. It occurred in both the buhr stone dressers who must have been exposed to considerable quantities of fine silica but only two-thirds of the ?c-rays of Warehouse men displayed it. John Smith, who had worked for 10 years on the Bates Packer where he would theoretically inhale large amounts of silica had a normal chest picture. This warehouse group of only 6 men is probably too small and the duration of their exposures is too limited (all under 1 2 years) to permit statistical analysis. Possibly if the group were larger the figures would have proved more enlightening. It is still our belief that if silicosis should appear after further exposure it would occur in men exhibiting an "F" type of roentgenogram. One man, Monette, a mason and bricklayer for 9 years, as already mentioned, showed a change classified as F3 . In his case the accentuation of the linear markings was accompanied by a sug gestion of beading along the trunks such as occurs in early sili cosis. This man may have inhaled considerable quantities of silica in his work of repairing furnaces and calciners which are presumably lined with refractory silica brick. However, even he could not be called a case of fully developed silicosis. Tuberculosis was always manifested as healed lesions in the roentgenograms. The changes were of two types, (1) the "child hood type" which represents the first contact of the body with the tubercle bacillus and (2 ) the "adult type" which occurs when the body is again infected with this germ. The childhood reaction con sists of one or more isolated nodules of tuberculosis somewhere in the lung and another focus in a lymph node situated at the root of the lung. Such nodules of infection tend to heal with a deposition of lime salts which renders them easily visible in an x-ray film. In the gypsum workers these nodules healed with an excessive deposi tion of lime so that they were unusually large. The incidence of such infectious lesions was no greater than that in any group of individuals. The other type of tuberculous change, the "adult lesion" generally occurs in the upper portion of the lung. It also normally tends to heal but occasionally it spreads and gives rise to wide spread manifest clinical tuberculosis with symptoms and possibly fatal termination. Five or possibly seven in this series of gypsum workers showed evidence of a previous adult type of tuberculosis, but in every case Hie lesion had completely healed without exhibit ing the slightest tendency to spread. If a corresponding number of men exposed to pure silica dust were in question, it is safe to assume that some of these adult types and possibly: even the child hood types of tuberculosis would have shown evidence of spread and progression. 49 Following is a list of the individual workmen, grouped `according to occupation, together with their x-ray findings. 10 Block Plant Only, 7 to 21 Years Employed Name 7 yrs. Frank Manke 8 yrs. A. Ferri3 11 " C. Brown 1 2 . " . F. Waterstreet 13 " B. Newton 14 " Fred. Manke 15 " Al. Rumsey 16 n M. 0Instead 19 " Carl Lutz 21 " F. TJrtel Case No. X-Ray 46 . . . ........ F 2 48 . . . ........ F 2 41 . . . ........ P 2 23 . . . t 45 . . . ........ P 2 47 . . . ........ F 2 2 2 . . . ........ P 1 42 . . . ........ P 2 19 . . .......... P 1 43 . . . Complex 2 Buhr Stone Dressers 9 " H. Whitney 38 ( 6 yie.elsewhere ) Fg Primary Complex,Rt 1 1 "part) C. Rinehart time) 40 . . ?Tuberculosis 10 n 9 " 9 *' 9 10 M 11 " Cummings 1 Laboratory Tester 1 0 1 . . . . . . . . Pi 22 Miners E. Cassiano C. Nelson (Brusher) J. Jerome (Loader Hard Coal) A. Domaogoila S. Scopano (Pig Iron Loader 2 years) 77 . . ..........Pi 76 . . 61 . . .......... * 2 62 . . 57 . . .........Fj emphysema apices ' Employed 1 2 years 12 it 12 12 h 12 it 1 2 it 12 h 1 2 It 13 # 16 it 17 h 17 18 tl 19 II 2 1 II 24 It 25 II 5 II 7 II 8 II 8 It 8 It 1 0 II 1 0 II 22 Miners (Continued) Name Case No. X-Ray J. Malta 78 . . . . . . Pi D. Paolucci A. Paolucci 74 . . . 63 . . . . . . P-J,. Primary complex,Lt. . . . PX A. Frigoni 64 . . . . . . f -l Primary complex,Rt. N. Paolucci 67 . . . . . . Fl Large Heart A. Ferrari D. DeAngelis S* Xanni 68 . . . 69 . . . 70 . . . . . . f2 . . . PX Primary complex, Rt. . . . Fl F. Yanik 71 . . . . . . Pi Large Heart P. Taddei 80 . . . . . . PX E. Capone S. Hallat 73 . . . . 1 0 0 . . . . . . Px Calcification Rt. Apex G. Cafero ,6 6 . . . . . . Fl J. Callanan i 75 . . . . . . Fi J. Balonek 79 . . . . . . PX Emphysema R. Cure 24 . . . . : . ? 1 P. Malta 96 . . . . . . Pl 19 Board Plant Only L. Eeidenrich 52 . . . . . . FX J. Woods B. Werth (2 yrs. outside) E. Green 54 . . . 53 . . . 25 . . . . . . F1 Primary com plex, Rt. and . . . Fx Lt. DVi*tVtUoV . . . P2 Ditto to. Adams 56 . . . . Winkstern 37 . . . . . . 0 S. Davidson 35 . . . . . . P2 Calcified : both apices 4 Employed 10 years 10 1 0 fl 1 0 it 11 n 1 2 tt 12 11 13 ti 14 11 15 11 16 ti 22 11 19 Board Plant Only (Gontlimed) Name Case No. X-Ray T. Perfitt 3 4 ......... 0 E. Bumstead I. Davis S. Davis M. Allen R. Harris 32 . .- Fi 3 . . Pi 2 . . * * * * P1 30 . . . . . . . f 2 26 . . . . . . 0 Primary complex,Lt. 11 W. Greene 36 . . P. Taber 31 . . . . . , P2 V. Seaburg 24 . . . . . . F2 W. Allen R. Allen S. Dick 33 . . pl 29 . . pi 27 . . . . . . FX 5 it 6 ti 6 11 1 0 tt 11 11 12 11 6 V/arhouse Only R. Valena Fred Bernard Wm. Shepard John Smith (Bates Packer) A. Beckwith T. Joslyn 14 . . . . . . FX 11 . . 10 . . . . . . f2 51 . . 17 . . Pi 16 . . . . . . FX Primary Complex, Lt. 9 Warehouse and Occupations Elsewhere in Plant 5+5 tt 5+25 it Wm. Farmsworth E. Dinehart 5 . . 13 . . . . . . pl8 x,Rt.+ Lt. 0 7 1 /2 + 1 yrs. Natzka 9 . . . . . . f2 8+3 yrs. 9 +1 11 E. Earl A. Hensel 7 . . . . . . f2 93 . . . . . . f 2 52 * 9 Warehouse and Occupations Elsewhere in Plant (Cont.) Emolo7/ed Name 9 1 /2 + 2 1 yrs. J. Reddins 1 0 + 19 " Mike Marrah 1 2 + 1 0 M Chas. Miller 15 + 7 M Burt Smith Case No. X -R ay 1 2 ........ 15........ 6 ........ 8 ........ . F2 Primary Complex Rt. + Lt. * P1 Fi plex Rt.+ Lt. 9 years 11 ii 12 it 12 ii 15 it 13 15 it 15 ti 16 it 17 tt 20 tt 21 tt 25 tt 13 Miscellaneous with Occasional Work in Warehouse Chiefly Repair and Maintenance Crew A. Monette (Mason, boilers and flues) P. Miller (Carpenter) D. Bowden 84........ 87........ 85.................................... F3 * F2 . 0 E. Bogden S. Posdick Balfour 83. . . . . 91........ 4 .................................... pi F1 . 0? M. Freiday E. Pender S. Christophero Nanni H. Holm 89.................................... 9 2 .................................... . F1 Primary Complex Rt 49. . . . . P 2 9 0 .................................... . Pi (Isolated TB. ( 88.................................... . P-l (both roots. M. J. Hordan . G. Lehman 97........ 9 5 .................................... F2 . F2 Primary Complex, Rt. 9 tt 9 10 tt 10 it 19 Miscellaneous - No `Warehouse Exposure D. Tillet F. Neth A. Burr L. Park 94.................................... f 2 98........ pl 20 Pl 2 1. . . . . Fi 'V - * j r'. ' '-V ' w` ' p K ti V4- 53# \--- s Y Employed 1 1 years 11 tt 11 tt 13 it 13 n 14 tt 14 tt 14 tt 14 tt 15 tt 15 tt 19 tt 21 it 26 tt 30 tt 19 Miscellaneous - No Warehouse Exposure (Cont.) Name E. Newton Case No. x -,R.a.y 44 . . . . . . p2 Kent 1 . . . . . . PX Ed. Hale 99 . . . . . . P2 Primary Complex, Rt. C. Manetta 50 . . . . . . f 2 B. Ianni (Mine 7 yes.) H. McGuire 81 . . * 2 28 . . E. Ernst (Bi'usher 8 yrs.) 55 . . . . . . FX R. Laurrey (Mine 9 yrs.) 60 . . A. Schulk 82 . . . . . . Fi D. Caton (Mine 12 yrs.) 72 . . . . . . f 2 K. Stevens 8 6 . . . . . . Px L. Joslyn 39 . . . . . . f 2 J. Ianni (Mine 12 yrs.) 65 . . . . . . Fl R. Schultz (Mine 11 yrs.) 58 . . . . . . f 2 A. Speed 18 . . * * ` F 1 Primary Complex, Rt. and Lt. Prom this analysis of the x-ray and clinical examinations, it would appear that gypsum dust inhaled in high concentrations over periods as long as 20 to 25 years does not produce changes in the lung which are incompatible with normal function. It cannot be maintained that this dust has no effect on the lungs for only 13 of the 101 men examined show what could be Interpreted as negative lung roentgenograms, c but there was no clinical evidence that gypsum inhalation had produced disability. When silica dust is also present in the industrial atmosphere with the gypsum dust this substance has not excited the reaction 54. ,wich experience in other industries would lead one to anticipate. At least 17 men appear to have had a sufficient exposure to silica to have brought about changes in their lungs demonstrable by x-ray but such changes could not be discovered. Two explanations have sug gested themselves: either that the gypsum by virtue of its physical properties clumps the silica particles in the air into aggregates too large to be inhaled or that gypsum chemically modifies the tissue reaction to silica. In the absence of any data on the subject it seems more likely that the former explanation may be the proper one. As suggested, further study of the atmospheric dust is necessary, and it would also be desirable to procure autopsy material from men ex posed as long as possible to mixtures of silica and gypsum, so that chemical analyses of their lungs might demonstrate how much silica actually penetrated their tissues. Opportunity for such a study is, of course, quite fortuitous. The investigation has also demonstrated a complete lack of progressive tuberculosis among the gypsum workers who were exam ined. This finding substantiates the view' that little silica has been inhaled, for any group exposed to silica for as much as 2 0 years should contain 10 to 15$ with active tuberculous lesions. It has been claimed that gypsum dust protects against tuberculosis. H. Maendl (Zeitschrift fur Tuberkulose 1921,XXXV,184) quotes Fissak, without citing the source of his figures, to the effect that of 40,824 deaths among lime and gypsum workers only 17 or 0.41$ were due to tuberculosis and that among 400 employees in one gypsum plant (presumably German or Austrian) no death from tuberculosis had occurred in 17 years. Exam ination of the death records in Oakfield and the nearby towns might demonstrate whether the incidence of deaths from tuberculosis or other respiratory disease was equal to or below that for other industrial . .. , wi -v..-- :..'- communities Two cases of active tuberculosis in gypsum workers ** . from Oakfield have come to our attention so that we know it can occur. PATEOLOGY - Lack of material forbids any elaborate discus sion of the tissue changes produced by the inhalation of gypsum in pure form or in combination with silica or other substances. Animal experiments are in progress but the exposure period has not been sufficiently long to hazard an opinion as to the nature of the reaction. One autopsy on a gypsum worker was obtained through the efforts of Mr. Daniels at Oakfield. This man was not employed by the U. S. Gypsum Co. but by a competitor for a period of 6 years, presumably in various capacities but his occupational history was not obtained in detail. No x-ray films had been made of his che3 t prior to his death so that a comparison between roentgenogram and pathological lesions was not possible. Presumably the picture would have shown an accentuation of the linear markings, as there was a rather marked accumulation of dust along the lymphatic vessels accompanying bronchi, blood vessels and the connective tissues between the lung lobules. These structures were pigmented by the dust and slightly thickened by the formation of a small amount of new connective tissue bub there was no.fibrosis and no nodules such as occur in silicosis. There were nodules in the lungs and lymph nodes of "childhood tuberculosis" which had healed with very extensive calcification. Death occurred from coronary arter ial disease which could not be associated with dust inhalation. The character of the pulmonary changes was that of the reaction pro duced by many non-irritating dusts, like soft coal and marble. 56 This report discloses that among the 101 long term ^ employees of the U. S. Gypsum Company who have "been examined, there is no case of definite silicosis nor one of active pulmonary tuber culosis. These findings were somewhat surprising in view of the fact that in some portions of the plant, notably near the mixer over the #12 Packer, there were total dust counts as high as 11 billion parti cles per cubic foot of air with a free silica content which might be as high as 3 billion particles. The facts that no silicosis occurred in the group of 6 men employed exclusively in this part of the plant, and that the one man who had worked on this particular machine for 1 0 years showed a normal chest, throws some doubt upon the existence of a hazard under the conditions encountered in this gypsum plant. As an explanation the hypothesis was suggested that the - . tendency of gypsum to form aggregates clumped the silica particles v into masses too large to be inhaled in significant quantities. Never theless it must not be taken for granted that with further exposure of 10 or more years these men would remain free from disease. The occurrence of an "F" classification in so many of the roentgenograms suggests that with continued exposure some of these men might ulti mately develop serious pulmonary damage. As far as gypsum dust is concerned nothing has been observed which would disturb our original feeling that this dust would prove to be quite harmless. Probably it is responsible for certain changes in the x-ray pictures of the lungs but there is nothing to indicate that these changes are associated with physical _ disability. Traces of active pulmonary tuberculosis are wanting and th experience quoted from Germany suggests that it is rare among gypsum workers. The evidence suggests that where a tuberculous in fection is present the dust inhaled in this plant does not tend to cause it to become active for 18% of the pictures showed well healed foci of childhood tuberculous infections and 5% of them disclosed healed adult tuberculosis. However, it cannot be claimed that such infection never becomes progressive in men with gypsum exposures. For these reasons it is of utmost importance to select for test cases individuals without active tuberculosis or obvious silicosis in order that unfavorable precedents may not be established that in the gypsum industry. If it can be discovered/perchance such con ditions exist among the group of cases scheduled for trial, we would urge that they be settled by compromise and that the test be based upon the typical case. DONa LD E. CUMMINGS ASST. DIRECTOR