Document 9Jg86xr4dngXJD15nkgx1Kazp

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 3y Jack Hunderle, District Industrial Hygiene Engineer ' J. R. Rushin and J. A. Wvnd, Assistant Engineers AA 0021646 Investigation of ATMOSPHERIC LEAD in the American Crucible Products Cor.oany 130? 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 Deoartnent of Health at the American Crucible ProductsComnany, l/Cf Oberlin Road, Lorain, Ohio. This request '.'fas a direct result of nine cases of lead poisoning reported to the Lorain County Health Department by Dr. 3. C. livers of Lorain during November 195 and January 1951. PAST HISTORY In March of 19A9, an engineer from this division visited the American Crucible Products Company because of a similar occupational disease reoort of lead ooisoning. His report addressed to Mr. Charles K. Herder, general manager, and dated April 12, 19A9, 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 and fume problem. The findings together with other pertinent information necessary for their interpretation are contained within this reoort. It is honed that this report together with the cast history of occupational disease will induce tk KB 0021647 ..anagement to eviev their present foundry practices and in the light of present day knowledge, institute adequate control measures that a healthful working wivirormoni way be at'-ained. i 1 ! C'.Hj '-J u u >_ - _ j - h ' . y j the American Crucible Products Company is engaged in the manufacture of bearing bronzes and babbitts. Various alloys are used in vrhich the lead analyses range from 2 to 2 per cent lead. These melts are accomplished in crucibles placed .in the eight floor furnaces located in the furnace room, then brought to the proner heat, the crucible is extracted and placed at one of two points for skimming, (see Figure 1.) After skimming the crucible is transported by -onorail to one of the several revering stations. In all cases except the north central pouring station, the molder accomplishes the pouring of his own molds. Any leftover molten metal is cast in pigs near the furnace root; for later remelt. liter cooling on the open floor, the castings are removed from the "'.olds at the points marked shakeout. The rough castings are then taken to the Tindir.v room where xcess sand and dust is further removed by enclosed wheel- 'racor machines. The casting aro then passed through cut-off, grinding, seerfirm-, filing, chipping and similar operations before being sent to the machine shoo for finish operations. bpAD. inTOXICATIOI? The usual symptoms of early or mild load intoxication are Pallor, listlessness, poor appetite, constant headache, constipation and slight abdominal pain. After prolonged exposure, these symptoms become more Pronounced, 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, eatinc at his work place 2. k f 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 '-outh by contaminated hands, clothing or objects. Lead nay be inhaled in two forms; as dust, as fume or both, '-"'he dust is ~reduced from filings, chit's and scraps on the table and floor and is disseminated into the air by brushing of the work area, by motion of the worker and by air currents. ike invisible fume arises from the hot lead and may be constantly in s^rrerundine t vor)*r. According to the regulations* of the Division of Industrial Hygiene the '-axirsum allowable concentration for lead in the work room atmosphere is 0.15 milligrams per cubic meter. This maximum allowable concentration (MAC) may be defined as that concentration which the average 'worker may breathe ner eight hour day over prolonged periods without harmful nr injurious effects. 7 I 5LD i -y&TiPd-SKTS At-mosrheric samules '-ere collected to determine Q ) the 'individual exposures, (2) general room-air conditions and (?) sources of contamintjon. Tie Hi no Safety Apnliance hlectrosta+ic Dust and Rime damnlm-r and the :id':f't Inpinger instruments were employed for this ournose. That accurate data night be obtained, +he samples were either collected at the breathing height of the 'orleer (for general room air determinations ) or in the breathing eon (for determining the specific exposure of an occrvoe.tion. ) Tn table T are listed in two promos the results of the room, air Bander,. The first group was collected with windows in the foundry closed and only those in tiie furnace room open. The other growo, listed at thm *nd of the table, was collected with window's in the foundry also open. These two grouns nay be considered to be representative winter and summer conditions respectively. * Regulations for the .Prevention and Control of Diseases from. Sxoosure to Toxic Fumes, Vauors, Mists, Gases and Dusts in Order to Preserve and Protect trie Public Health. Adopted by the Ohio Public Health Council, February 16, 1946 KF 0021649 TABLE I IN-PLANT ATMOSPHERIC SAMPLES OF GENERAL ROOM AIR Mdndo'is and doors closed - representative of vint.er conditions) j-mle Ho. . . . . ___ c C-21 C-2? C-26 C-27 C-29 C-?0 -p,-p r y C-?8 C-.A1 C-AA C-A7 C-A.9 C-5j. C-5? C-R/. n C~'6 C~ ',8 C-52 Position No. Concentration _ (.Milligrams per __ ---- -------- icubic meter)__ Description of Sample -- -- -------- -- 2 3.65 General room air - Vicinity pouring - foundry A 3.76 tt IT ti 11 molders 1, 2 & 3 Q 2.90 tl 11 h U pouring 1 2.A7 tf It n M pouring 3 2.02 ti11 11 1! shakeouty molders A g 3.72 U n ti 11 loafing bench s 3. A3 It ii n 11 molders 6, 7, Hi 8 11 M 56 ii11 n M furnace room 10 2.9A ft ii ii 11 Holders 6, 7, 1-8 .12 1,31 1A 1.82 16 ,37 .05 .08 -- .07 1,65 . 1.24 -- 1.20 11 i i u t ! n ti 11 n u tiH i i 11 (i ii n ii ti n n ii n n ii ii n it 11 store ore ara Tt grinding room 11 grinding room 11 Center machine shot 11 machine shop - cent 1! machine shop - '-rest !1 grinding room - r'es 11 ii it -nor+ It tt it -east 18 .56 Specific O C C l .it)fli ion - disc grinder 1"QX 2.04 tr rt - cut off machine operator 20 2.19 ii ii - filin g and scarfing GENERAL ROOM AIR (Mi.ndous open representative of summer conditions) C-62 C~6a C--66 C-70 C-72 C-74 21 22 2. 9 i 26 .22 6.42 .78 .88 .45 .18 Vicinity leftover pouring " furnace rots " pouring - foundry No pouring in vicinity Vicinity poi.:ring No pouring in vicinity In table II are listed the results of those samples collected of complete ro\u operations beginning vdth the removal of crucible from the furnace and ending vith 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 sample. -A- HE 0021650 TABLE XT SAMPLES OF POURING OPERATION Kelt No .1 i 6SK 1. ? 660 qcc ' 9 o o c; Load in Melt 2e).00 15.00 9.00 Atmospheric Concentration mgms./ cubic meter 10.8/. 8.?A 7.12 ?.09 - -Average of two samples - ..Average of eight samles -- average of tiro samles - Average of turo ssmaeles Samles of settled dust more collected at various uoints ?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 Samule No. Description of .Samle C-24 C-- 25 C-K6 C-f? C-5-S C-f;9 foundry room - east of molders 1, 2 & 3 - from switch boxes, etc. t! tt _ nori'.h of cooling ?* pouring stations - off windows tl it ,, south side foundry - '-rest of furnace room - ledges I! H ,, south and west ^nds of foundry - ledges Grinding; room - east end. tr ;i - wost end u Lea 0.5 n ,7 1 ,g -. 1 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 entering the plant. TABLE IV OUTDOOR SAMPLES Sample No. C-60 C-61 C-3 C-65 Position No. 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-4-5 degrees to dor-rnwind position H 0021651 B3T55l|^^A Tipi'I_ 0F_ 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 plant. Only in the machine shop mere the lead concentrations in the general room air within the maximum allowable concentration of .15 milligrams per cubic meter. The samoles in the other areas ranged as high as 37 tines the allovahie. It mill 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 was 2, A times the allowable. In table II, one may observe that the concentrations during Touring 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 uer cent of lead in the melt-. Observation of the analyses presented in table TV reveals several facts. Samples C-61 and C-63 show the air entering the niant 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 niant 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 nolli'.ted 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 exoosed to heavy atmospheric lead concentrations immediately dangerous to the5_r health. The nrinciole sources of atmospheric pollution are the floor furnaces, crucibles - as they are skimmed and transnorted through the foundry, pouring oneration, 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 nrovide inadequate control of the lead pollution problem. The air re-entering the olant from the outdoors was found to far exceed the maximum allowable value of lead. This in cart explains the ineffectiveness of the present dilution (general) ventilation system. The atmosphere immediately surrounding the riant may contain sufficient Quantities of lead as to be a nubile health menace. URCa-lSUDATIOlS It has been emphasized previously that the sources of contamination are numerous, that the present system of ventilation is inadequate, and that most of the riant 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 primary consideration. t 1. Operations in the foundry should be so arranged and the necessary equipment -ourchased to cause flasks to move continuously on a conveyor from molders '\ to nour stations to shakeout 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, ut specific points where corralet -7- RE 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 '-n.nt.er when It is needed and throw it away in the summer when not needed. ?. Jill 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. Evar-orative cooling might be employed to combat the excessive heat. 4, The practice in modern foundries Is to use cooling tunnels or can instead of allowing the metal fume to escape into the plant atmosphere. where mold conveyors are used, fairly closefitting, 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 funnel inlets at floor level. This gravity system has the disadvantage that smoke, dust, etc., nay 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 when, with the gravity system, the air would have to be tempered before entering the workroom. -S- 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 '..dll of course ho limited by several factors inclxtding the sice and shape of the castings. The enclosed hood is limited to relatively small castings vhereas the side draft hood is applicable to castings of nearly any size. The side draft hood hot'ever ret 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 ' 'lord or presenting a public health problem in the neighborhood can only be accomplished by the removal of the lead dust and fume from The air exhausted from the building, ^his has been successfully accomplished in other instances by the use 0r an electrostatic precipitator. The high efficiency of such a device together math moderate dilution of the effluent should completely eliminate the can e'er. 7. Every effort should be made to prevent trie unnecessary ingestion lead. .In adeouate instruction program should be instituted regarding personal and plant practices. The employees should be instructed in personal cleanliness and in the handling of foods, beverages and tobacco during v-orking hours. Good housekeeping practices, such as improved building and equipment maintenance, constant routine use of industrial vacuum cleaners, redesign of equipment and props" illumination may be expected to eliminate some of the dust sources. _Q-- g f 0021655 PR. OCX CO. O 'n w o i - soi WOO sas^oo-JM a*Mion*3 N\nt?3wv z x& QNfiQJ - ^ TF e-El-T c D SV t Y O L :>Tc^ u ai _ 291200 3 /H 4 n 0 0 C > m "O o ro 05 cn - Hi oz * 53 o i 2 d ? f* O > TO Q - t/1 Z / n tH H jx -O