Document 8R3JMEomgK2gN55818r2z36Q5

STATE OF OHIO DEPARTMENT OF HEALTH Division of Industrial Hygiene Thomas F, Mancuso, M. D,, Chief Investigation of ATMOSPHERIC LEAD in the American Crucible Products Company 1305 Oberlin Road Lorain, Ohio By Jack Wunderle, District Industrial Hygiene Engineer W. R. Rushin and .1. A. Wynd, Assistant Engineers KA 0021646 Investigation of ATMOSPHERIC LEAD in the American Crucible Products Company 1?05 Oberlin Road Lorain, Ohio At the request of the Lorain County Health Department, an industrial hygiene survey of atmospheric lead was made by the Division of Industrial Hygiene, Ohio Department of Health at the American Crucible ProductsCompany, 1705 Oberlin Road. Lorain, Ohio. This request was a direct result of nine cases of lead poisoning reported to the Lorain County Health Department by Dr. B, C. livers of Lorain during November 195 and January 1951. PAST HISTORY In March of 1949, an engineer from this division visited the American Crucible Products Company because of a similar occupational disease report of lead Poisoning. His report addressed to Mr. Charles K. Merge", general manager, and dated April 12, 1949, was mainly concerned with the control of lead exposure at the working position of the reported case. Material contained in this report supplements the previous report and completes the Division's investigation of the problem. OBJECT OF STUDY The purpose of this study was two fold (l) to ascertain the extent of air pollution due to lead dust and fume in the work room atmosphere and thus compare the results found with quantities known to be harmful and (2) offer recommendations of a general and fundamental nature concerning control of the lead dust ana fume problem. The findings together with other pertinent information necessary for their interpretation are contained within this report. It is honed that this report together with the oast history of occupational disease will induce 0021647 .anarrement to review their present foundry practices and in the light of present day knowledge, institute adequate control measures that a healthful working r-nvirorient way be attained. the American Crucible Products Company is engaged in the manufacture of bearing bronzes and babbitts. Various alloys are used in which the lead analyses raiipe from 2 to 2 oer cent lead. These melts are accomplished in crucibles olaced In the eight floor furnaces located in the furnace room, then brought to the oroner heat, the crucible is extracted and placed at one of two points for skimming, (see Figure 1.) After skimming the crucible is transported nv "wnorail u ore of one several rourinv stations. In all cases except the north central pouring station, the molder accomplishes the oouring of his own molds. Any leftover molten meoal is cast in pigs near the furnace room for later rar.elt.. After cooling on the open floor, the castings arc removed from the "'.olds at the points marked shakeout. The rough castings are then taken to the Tindir.-~ room '.taro excess sand and oust is further removed bv enclosed wheel-- 'racor machines. The casting arc then passed through cut-off, grinding, scarfin'*, filing, chinning and similar onerations before being sent to the machine shop for finish operations. IFAD INTOXICATION The usual symptoms of early or mild lead intoxication are pallor, listlessness, ooor appetite, constant headache, constination and slight abdominal pain. After prolonged exposure, these symptoms become more oronounccd, certain . blood changes become easily recognizable and lead accumulates in the body with occasional fatal results. Lead may enter the body by ingestion and/or inhalation. A worker, carrying tobacco in his work clothes and smoking on the .job, eatinv at his work pi. 2- - Kf 0021648 without thoroughly washing before eating, may ingest a considerable nuantity of lead. Unless special precautions are taken, the lead may be conveyed to the -owth by contaminated hands, clothing or objects. Lead nay be inhaled in two forms: as dust, as fume or both. 'Tie dust is ^reduced from filings, chins and scrams on the table and floor and is disseminated into ~re air by brushing of the work area, by motion of the worker and by air currents. The invisible fume arises from the hot lead and may be constantly in -- no q t "iq o rhorQ P,1T*T*C\.`inCli.n<f *"!.?? VrOI*} According to the regulations* of the Division of Industrial Hygiene the '"axitEEi allowable concentration for lead in the work room atmosphere is 0,15 milligrams ner cubic meter. This maximum allowable concentration (MAC) may be defined as that concentration which the average 'worker may breathe per eight hour day over prolonged periods vdthout harmful nr injurious effects, FIELD ]-j/>STiRlS-SKTS At-mosrheric samples i-fere collected to determine Cl.) +he individusl exposures, (2) general room-air conditions and sources of contamination. ^he vine Safety Apuliance Electrostatic Dust and hoe Cannier and the 'bywvr-t Lupinwer instruments were employed for this purpose. That accurate data .might be obtained, the sararles were either collected at the breathing height of The 'orker (for general room air determinations) or i.n the breatbd.nv "on (for determinins1 the specific exposure of an occupation.; In table T are listed in two groups the results 01 the room, air sanpj es. The first group was collected with windows in the foundry closed and only 'those In the furnace room open. The other group, listed at thm e-nd of the table, was collected with window's in the foundry also open. These two groups nay be considered to be representative of winter and summer conditions respectively. * Regulations for the .Prevention and Control of Diseases from. Exposure to Toxic Pomes, Vapors, Mists, Gases and Dusts i.n Order to Preserve and Protect the Public Health. Adopted by the Ohio Public Health Council, February 16, 1946 KF 0021649 0- - TABLE I IN-PLANT ATMOSPHERIC SAMPLES OF GENERAL ROOM AIR f'dndous and doors closed - representative of winter conditions) i-nie Ho. c-o C-21 C-2? C-26 C-2.7 C-29 c-?o vj *-- ~ c-?s c-a c-// C-47 C-4.9 C-5j. C-5? c-R/. /O-\ -'-iOf C- ',8 C-52 Position No. ______ ______ Concentration _ (.Milligrams per cubic meter)__ Description of Sample ________ __________________ 2 3.65 General room air - Vicinity pouring - foundry 4 3.76 tt tt tt tt molders 1, 2 & 3 Q 1 2.90 2.47 tl it u tf it n tt pouring tt pouring 3 2.02 II n tt It shakeout-4 molders 4 g 3.72 It it tt tl loafing bench 8 3.43 It it tt It molders 6, 7, P 8 11 d?6 11 Tl n It furnace room 10 2.94 ft tt n tt Holders 6, 7, g 8 .12 1,31 ft 11 tt tr storage ara 14 1.82 t! 1! tt Tt grinding room 16 ,37 It tl u t! grinding room -- .05 tt tf tt tJ Center machine shot -- .08 tl tt it It machine shoo - cent _ .07 ft 11 tt It machine shoo - 'rest -- 1,65 fl n tt !t grinding room -- ves -- 1.24 n n tt It !! It -nor+ - 1.20 t: n tt tt it I! -east 18 .56 Specific OCCl }r)CT*r n.on - disc grinder 1 "Qg 2.04 tr n - cut off machine operator 20 2.19 tt tt - filin g and scarfing GENERAL ROOM AIR (Windows open representative of summer conditions) C-62 C-64 C--66 C-70 C-72 C-74 21 .22 22 6.42 2 .78 9 .88 i .45 26 .18 Vicinity leftover pouring " furnace mots " pouring - foundry No pouring in vicinity Vicinity pouring No pouring in vicinity In table II are listed the results of those sarmies collected of cotn.nlete pout onerations beginning t-dth the removal of crucible from the furnace and ending with its return to the furnace room. Since the lead content of the different melts varies, this and the melt number are also given for each samole. 4- - HE 0021650 TABLE XI SAMPLES OF POURING OPERATION Melt No. .1 6 X 6SK 1 ?: 660 P.GZ, 9 O O c; Lad in Melt 29.00 15.00 9.00 Atmospheric Concentration mgms./ cubic meter 10.8/, S.24 7.12 ?.09 - .Average of tvo samples - ..Average of eight samples -- Averse of tvo samples -- Av^ra^e of tvo samples Samples of settled dust wore collected at various points ?n the foundry and grinding rooms. The per cent lead is reported in Table III and serves to illustrate the -point that settled dust is a source of contamination and may contribute to the general room air pollution. TABLE III SETTLED DUST Sample No. Description of .Sample C-24 C--25 C-K6 O-V7 C-5-S C-f;9 foundry room - east of madders 1, 2 & 3 - from switch boxes, etc. t! H _ north of cooling 1 pouring stations - off vindovs tl it -- south side foundry - '-rest of furnace room - ledges I! u ,, south and vest nds of foundry - lodges Grinding; room - east end. tr it - vest end 4 Lea 0.5 1 ,g -. 4 1.0 10.0 In Table TV are presented results of several samples taken outdoors of the plant. Only a sufficient number were collected to indicate the quantity of atmospheric lead in the plant vicinity and in the air enterinf? the plant. TABLE IV OUTDOOR SAMPLES Sample No. C-60 C-61 G-63 C-65 Position Ilo. 27 24 23 25 Concentration Description of sample Mgms/cu. mtr 0.0 .19 .30 .12 Aerated blank -- 90 degrees upwind Return air from outdoors to plant Return air from outdoors to plant Outdoor air-45 degrees to do^rrn/ind position 0021651 IIJT5KPR5TATipi'I_ 0?'_RESULTS From inspection of the above tables I and II, it is obvious that a very serious hazard due to lead polluted work room air exists at the American Crucible Products riant. Only in the machine shop were the lead concentrations in the general room air within the maximum allowable concentration of .15 mill!prams per cubic meter. The samples in the other areas ranged as high as 37 tines the allowable. It will be noted that the concentrations tend to decrease with distance from, the furnace room, ie. - general room, air concentrations in the furnace room were 37 times the allowable whereas in the grinding room, at the furthest point from the furnace room, the concentration vras 2,4 times the allowable. In table II, one may observe that the concentrations during pouring operations are extremely high - as much as 72 times the allowable. It should he noted here that such high concentrations may be more dangerous than low concentrations for proportionally long periods of exposure. As would be expected, the atmospheric concentrations decrease with the per cent of lead in the melt-. Observation of the analyses presented in table TV reveals several facts. Samples 0-61 ar.d C-63 show the air entering the plant to be highly Polluted and a source of contamination of the general room air. This explains in part, the inadequacy of the present dilution ventilation system. The air exhausted from the plant is replaced by outdoor air which is already polluted to the extent the lead content exceeds the maximum allowable. Sample C-65 indicates that the atmosphere in the immediate vicinity of the riant may also be sufficiently polluted to be.a health hazard. COKCLUSIOIiS The results of the air analysis data prove beyond doubt that a very serious health hazard due to lead contamination of the workroom atmosphere exists at the American Crucible Products Company. This health hazard is not confined to the 6- - 0021652 furnace room but is a general condition throughout the furnace, foundry and grinding rooms - the lead concentration varying in severity with the distance from the furnace room. It is the opinion of this office that workers in these areas are exposed to heavy atmospheric lead concentrations immediately dangerous to their* health. The principle sources of atmospheric pollution are the floor furnaces, crucibles - as they are skimmed and transported through the foundry, pouring operation, cooling - shakeout areas, and the air re-entering the plant from the out-of-doors. The roof and wall fans comprising the present general ventilation system provide inadequate control of the lead pollution problem. The air re-entering the plant frora the outdoors was found to far exceed the maximum allowable value of lead. This in part explains the ineffectiveness of the present dilution (general) ventilation system. The atmosphere immediately surrounding the plant may contain sufficient quantities of lead as to be a public health menace. :y:ica:T:imiDhTlP^ It has been emphasized previously that the sources of contamination are numerous, that the present system of ventilation is inadecuate, and that most of the plant atmosphere is so highly polluted with lead that there is immediate danger to the health of the employees. The following recommendations are intended only to call attention to these facts and to those operations which it is believed should receive urinary consideration. t 1. Operations in the foundry should be so arranged and the necessary equipment purchased to cause flasks to move continuously on a conveyor from molders \ to pour stations to shakeou.t and return. This flow of material is used in many modern foundries. The control of air contaminants is greatly simplified because the molding, pouring, cooling and shakeout are conducted, at specific points where comelet 7- - K E 0021653 local exhaust ventilation is possible. 2. A properly designed, highly efficient local exhaust system should be installed for all floor furnaces. It is possible to plan and locate +he furnaces so as to be able to use the waste heat by steam or hot water exchange in the winter when It is needed and throw it away in the summer when not needed. ?. j UI pouring operations should be centralised that only a single local xhaust hood would be needed to obtain effective control of the contaminants, A properly designed side draft hood should have the ton extending as far as possible over the side of the flasks and should be constructed of a non-reflecting material. `The usual procedure is to locate the pouring operation immediately contiguous to the furnace room and separate these operations from the rest of the foundry by means of asbestos board partitions, thus keeping all molten metal operations in one zone '/here a high rate of ventilation with clean washed air is maintained. LVarorative cooling might be employed to combat the excessive heat. 4, The practice in modern foundries is to use cooling tunnels or canopies instead of allowing the metal fume to escape into the plant atmosphere, '..here mold conveyors are used, fairly close.fitting, heavy-gage metal tunnels from pouring station to shakeout, with gravity vent stacks, have sometimes proved satisfactory where makeup air Is adequate. This makeup air is generally provided by tjyinel inlets at floor level. This gravity system has the disadvantage that smoke, dust, etc., may pour out of any openings, A more satisfactory and proper method is to install an exhaust fan to assure positive movement of air. It is then possible to bring in makeup air from the out of doors at one end of the tunnel and exhaust it at the other. This results in a considerable fuel saving in the '. /inter season '/hen, with the gravity system, the air would have to be tempered before entering the workroom. 8- - K 0021654 5. The most effective control for shakeouts is the relatively complete sure hood with a sufficient exhaust volume removed at the top to maintain ete collection of fume, dust, expanded air and steam. The decree of enclosure v,dll of course ho limited by several factors including the size and shape of the castings. The enclosed hood is limited to relatively small castings whereas the side draft hood is applicable to castings of nearly any size. The si.de draft hood hot'ever rer Hires exhausting of a larger air volume and is therefore more expensive to overate. 6. Elimination of the present danger of contaminated air re-entering the '-'Isnt or presenting a public health problem in the neighborhood can only be accomulished fay the removal of the lead dust and fume from The air exhausted from the building, ^his has been successfully accomplished in other instances fay the use o-f* an electrostatic precipitator. The high efficiency of such a device together with moderate dilution of the effluent should completely eliminate the cancer. 7. Every effort should be made to prevent trie unnecessary ingestion of lead, .in adeouate instruction program should he instituted regarding personal and plant practices. The employees should be instructed in personal cleanliness and in the handling of foods, beverages and tobacco during working; hours. Good housekeeping practices, such as improved building and eouinmenb maintenance, constant routine use of industrial vacuum cleaners, redesign of equipment and proper* illumination may be expected to eliminate some of the dust sources. _Q -- gt 0021655 r .' ame . . gym. ** m. OUTOOOR'i ^YN- .,)aw..COOT jrt /ftfsck f't i f: >0' iAOSttMAOtjj i C*K I \ ;t5l A c 3 T 0 A @ jI L. ._J i OWtkT teovutT4'ik ___i. p A T T E f? N s T 0 e A G t in O O > \ 4, * '` i .<******: i f %KOf* LEQENO (l$> - CUTor? 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