Document bB3GJvK5xZOzGEDewXM5LvV7g

December 19# 1938 MMAnar.aricoFon*n*daEI,nWHdiiararefncaand Cable Company Dear Mr. Hart* . adyaotttthhhoocbbieoucecstaoauyobfsitougrneoupuenhdegrrtttndeigoedittpefnhhatslinefaattdobiotnoaoreftnmvf.tsbhsyotayHaeoikdwrutliooenamlrwhngyiemmcwctvhehsoaoeieukgrbrkceoIhsmhdsfteomaIaermbfnctvauahbeeedaawrerrttvstaioihhaooeneafimeidncftnhrneosroit.uenhrwfdrepafediecocoAoofrorefttrubmmciotimbsc*crmnaetoseuotrreigyvtdlonooiitainndvuifnfteauiigontmwsrltlienghyol.yhmysneiscyevImholiienuthsboawaiedvtere mmwwhhhawSyfaanalooooasptitienahonneeebnoftofahctoamehhwaddhdrikdultcraiiiesd*metleaydeeccsetir,nueuhshhho-oatritaepahdmcnebewfcaaoyuntrdaoeoyonneslehaafIraihtenmyantahrnfnntctilieimeeoneaaglcagcwcataootmpnhdadaahvnabsrt.ntaoemedosegitewetrittasncuetnhdehmisehIrjleoeyalt*aboihdudhaoatOs.mr.rnpwtwrvnanhlifntitpstolgensodenospIneoioititunntsisTohitIirttoytonghhofhgmtlahhsltietoeirhoocoeeswenhaesotrieyammroaesshvccattf.oyddhodvtavsieolraireednetvifkeonyipeoeltubaaraeheocrpIfofvooririddgecnauolwfondeeteofataewytincteeuntsroililh*ahaewhetxutscaseaoIsofcichdhioneecuorsil.pntbasteorknehayohnrfItirotimtrsmmnnesiwpeaiiprisofdlsmmnTsveeedtieturaolrihnh*mmneischgoxttnrpeiiaishheviwsneeofsoyl.kieptdnedoeen!osioftniajhilsdnkbuhaonnTtloopoltfbseivvmrsgesiytnriethan*nehnayitobeTeysaert.itllagcmdgehesseontrileaitihgroeaaeeuhbtttplaanngehryirswdwpftTteaisuttedioioghdlehtn,laiau.iogttaahvml*mew*ausdaiesrsriinihiaesdgsdeswsseIdttrietddoswennO.tctoetiohhsnocardIraofhtto1fcnhrohsaneesao3giotftostoioenehrftocOcdsptunifamah*daguswhotaspnuttrrbiitdhohaoecrnliatuttteluyheeedtMoidarotottcsramh*hsesosatftefuttkttrhhheeewsepatbmnt.eesheiswriterlttaessseohheoasIxasm*tiabvegnsnstaepittdhymhlesoutofemtafttsmlorheauttpanoctarrtoyeelttmyssbes 2 mmhwaetIItiotihhonsoxtthbeeteactelpatddhdnneraifociiesoifixccshnntaae,rtaeauoeekhcmsllrrdditatcetnphshsat.titlghhsuresiioeneseeoospryDpneinfeeserdctftorereitehosovtomacrsahewrntiunpeseeseIavbsiocniuy,ttsoitneoegticfimnsoutiettnyhaitarnltoochnehcoesundmfoictaftrmhsohmaateeawprsatalbifhzndInroeaagsepostavrnhkrhccitttrdmcebhaaaoatoevyhun,uefecuuepndirttsowsiwtIi,,imolmntihhlinndhtitnaooiinhrseccidtsaenahihheitndsngweefinkseandpritrhisesceorulefaetmolttsshehmmw,cfitpreseftriooelhiasmynrnorlnieweceagol.yoecvtrtaednsewbecesorieofmcaiidacmiciitflpnnnoaalrcotplenneoro*ecbarrmttoyhhtwebeebeepeeceanetetayIaots*lntif.lned rveapluoer.t which I send herewI ittrhu.osft ysoomuewiinltlefriensdt athned Very truly yours, RAKjis Robert /u Kohoe, M~D, t Kt 0020967 MAGNITUDE OF LEAD EXPOSURE It? MARIO, INDIANA PLAN'S OF ANACONDA WIRE AND GABLE COMPANY Air samples were taken In the immediate vicinity of a melting pot In which scrap lead fro cables was being melted* Detailed observations sere mad over a period of an hour and a half In order to note the conditions which were moat favorable for the distribution of particulate lead compounds In the atmos phere* It so happened that the end of one ohlft and the beginning of another cams during these observations. Ibis period Involved the removal of dross from the melting pot* an operation which occurs once per day, and which Involves such greater disseminatLon of dust than that associated with any other procedure. Air samples were taken from several points about the pot, at the height of the operator*s face, during the period of normal operation* These samples were composited into Sample t*l* Another series of samples, similarly combined as Sample *t2 were obtained during the filling of the pot and during the removal of the dross* The analysis of these samples yielded the following results*- Sample #1 .21,ijli-O.Qml* contained 0*002 mg/Pb equivalent to 0.09 rag* per cu* meter* Sample 12 21,635*0 ml* contained 0*006 mg. Pb equivalent to 0*28 mg* per cu* meter* The values for particulate lead in atmosphere are usually expressed in terns of 10 cubic meters of air, and on this basis it is currently accepted that values in excess of 5 all!Igrigss per 10 cubic metera arc unsafe* Sonworkers give slightly lossy values# in aorainafcnncoa as low ns 1*5 milligram per 10 cubic motors. The evidence# however# is very good In Indicating that basic exposures aa lo aa that involved in bre thing air containing Z i"ligrssma of load per 10 cubic motors# are sub stantially safe for all workers regardless of susceptibility factors* On this basis of comparison the values observed In the vicinity of the pot ay bo regarded as Indicative of safety# in that the basic lead concentration has appeared to bo in the neighborhood of 1 milligram per 10 cubic meters# hu the brief periodic exposure# during dressing and shoveling is of the order of 2*$ to 3*0 nllllgrmna per 10 cubic meters* *ly osper-lence to Industry leads r.o to believe that this degree of exposure does not induce sufficient load absorption to cause load poisoning* This conclusion la fully verified by the results obtained in the semination of 2 employees whose work has involved daily exposure to such lead as la regularly distributed into the atmos phere around the pot* neither of the two workmen showed any clinical evidence of occupational lead absorption* neither had a lead line# despite the presence of conditions in the mouth (pyorrhoea) which are favorable to the development of lead deposits in the gum tissue* neither of them showed any blood changes (anemia or stippling) suggestive of lead absorption* neither of themhad abnormal quantities of load in their blood and urine* had 0*0ipmg. Pb per liter of urine# and 0*03 mg# Pb por IDOgram of whole blood# hiic ^ ^ m K ^ h a d 0*03 rag* Pb per liter of urine and 0*035 ag* Pb per ISO grams of whole blood* These are quite within the limits of values found in perfectly nornal persona with no occupational exposure to lead compounds* 3 - Xconclude therefore fro the combination of thee data that the occupational cone*.Itions studied at this tine are not such m to entail the risk of lead poisoning in workmen. It is also my opinion that the conditions described m in existence at the time of the plaintiff*3 employment while probably i nvol vi ng somewhat greater exposure than that hieh occurs at present were not sufficiently different in type or magnitude to Justify an opinion that lead poisoning would have resulted fro the exposure Good clinical evidence would be required therefore to convince raa that tho plaintiff had lead poisoning at the time it as claimed that he- had By good clinical evidence I aeon that characteristic symptoms associated with load line of tho guns perhaps and certainly with excessive numbers of "stippled" red blood corpuscles should have been present* ho presence of ab normal quantities f lead in the urine or blood or in both at that tts would have been convincing while- the leek of ouch evidence is a serious fault In the plaintiff*a claim Beturnlng to the subject of "stippled" erythrocytes (red blood corpuscles) It is necessary to demonstrate the presence of abnormal numbers before significance can be attached to the phenomenon. "Stippled" erythro cytes occur In the blood of normal persons up to ten or more per fifty microscopic fields and they are found In Increased numbers In a wide variety of conditions which have nothing whatever to do with lead absorption 'Their presence without refernee to numbers or without knowledge of other concealtaut changes In tho blood is wholly without diagnostic significance* . Signed HE 0020970 Hobart A. KKHOE report asd m .com m iD A 'm m os cu m t an cghditk ns cbsdhved anacohca vans asd cadis co^fa^ at hah ion, iiidiaba. Air samples were taken In the Immediate vicinity of a melting pot in which scrap lead from cables was being melted. Dotal'' ed observations were made over a period of an hour and a half In order to note the conditions which were most favorable for the distribution of particulate lead compounds in the atmos phere, It so happened that the end of one shift and the beginning of another case during these observations. This period involved the removal of dross from the melting pot, an operation which occurs several times In each shift, and which involves much greater dissemination of dust than that associated with any other procedure. Air samples were taken from several points about the pot, at the height of the operator's face, during the period of normal operation. These samples were composited into Sample *+l. Another series of samples, similarly combined as Sampled were obtained during the filling of the pot and during the removal of the dross, 'The analysis of these samples yielded the following results s Sample Hi 21,144.0,0 ml, contained 0,002 mg/Pb equivalent to 0,09 mg# per cu, meter. Sample nZ 21,655*0 si# contained 0,006 mg, Pb equivalent to 0,28 mg, per ou, meter. The values for particulate lead In atmosphere are usually expressed in terms of 10 cubic meters of air, and on this basis it is currently aocepted that values In excess of 5 *2 milligrama per 10 cubic meters are unsafe* Some workers give slightly lower values* in some instances as lots as 1*5 milligrams per 10 cubic meters. The evidence* however* is very good in indicating that basic exposures as low as that involved in breathing air containing 2 milligrams of lead per 10 cubic meters* are sub stantially safe for all workers regardless of susceptibility factors* On this baais of comparison the values observed in the vicinity of the pot say be regarded as indicative of a reasonable safety* in that the basic lead concentration has appeared to be in the neighborhood of 1 milligram per 10 cubic meters* while the brief periodic exposure* during dressing and shoveling la of the order of 2*5 to 3*0 milligrams per 10 cubic meters* My experience in industry leads me to believe that this degree of exposure does not induce sufficient lead absorption to cause lead poisoning* This conclusion is verified by the results obtained in the examination of 2 employees whose work has involved daily exposure to such lead as is regularly distributed into the atmos phere around the pot* Neither of the two workmen showed any clinical evidence of occupational lead absorption. Neither had a lead line, despite the presence of conditions in the mouth (pyorrhoea) which are favorable to the development of lead deposits In the gum tissue. Neither of them showed any blood changes (anemia or stippling) suggestive of lead absorption. Neither of them had abnormal quantities of lead in their blood and urine* had 0#0i{. mg* Pb per liter of urine* and 0.03 rag* Pb per 100 grams of whole blood* while had 0*03 mg* Pb per liter of urine and 0*035 rag. Pb per 100 grams of whole blood. These are quite within the limits of values fouhd in normal persons with no occupational exposure to lead compounds. 3 Certain additional observations were mad in tfa plant and on the two workmen which wore not referred to in the preceding paragraphs* Samples of the feces of the two men were obtained on the morning after a day of normal work. Vie have found that such samples give a good Indication of the magnitude of the lead exposure* Unfortunately one of the two samples was too small to be useful but the other contained ragm* lead, a quantity which is suggestive although inconclusive evidence of significant lead exposure* A sample of dust was taken from the top of an electric switch or fuse box situated above a drinking fountain abcr* 10 feet from the melting pot* This dust was seen to contain small btfight globules of metallic lead, which evidently had been dis charged from the molting pot* %e analysis of this dust demon strated the presence in it of 23*1% of lead* There was a con siderable quantity of dust at this point, and it is believed that the analysis indicates the deasemination into the air of un necessary quantities of metallic lead in finely divided form* Just what operation in the plant is responsible for this situation la not apparent, but the matter should be investigated* On the basis of the combined observations, it is recommended that certain changes be made in ithe equipment and operating procedures. (1) * The fan which blows across the melting pot from the rear of the operator should be eliminated in order to avoid the distribution of dust into the air* (2) The melting pot could with probable advantage be enclosed  \4* ** on three aides in much the some fashion as a ehonical fuse hood, (3)* An extension of the ventilating duct should be extended to the area immediately overlying the pigging molds* (l}.)* The dross from the pot should be removed directly into a receptacle which la equipped with a tight-fitting top* Instead of malting use of an Intermediate tray which subsequently must be emptied into a large collecting receptacle* ($), Other sources of dust and fume should be sought out by means of periodic critical observation of all norking operations. When such sources are noted* they should be corrected* (6) . workmen on this job should be supplied 1th work clothes* and with double lockers* They should remove their clothing* put it In the clean locker and change to work clothes (kept in the other locker)* At the end of the shift* they should reverse the process* bathing before resuming their clean clothing. (7) Quite In addition to the advantages of greater safety to the workmen* experience has shown that pro-employment and periodic examination of workmen in hazardous trades* or in trades which are generally asswaed to be hazardous* provides a consi-de.rable security to the employer against mistaken or fraudulent claim of occupational injury or Illness. Such exam!nations should be carried out with precision* If done properly they will prove useful for the recognition of hazardous exposure* The advantages of such in formation are considerable in view of the frequency eith which operating changes occur In manufacturing plants* When vague or uncertain types of Illness appear among workmen* it is advisable* from every point of view* to make complete clinical studies and to arrive at diagnoses which can* if necessary* - 5- be substantiated In court The type of medical service which will accomplish this purpose, will deserve the confidence of workmen and will prevent difficulties like the cases recently at issue, while at the seme time, it will inform plant; management as to the status of such occupational hazards as arise from the operation of a plant# Such medical supervision is recommended, at least, in the case of men engaged in work which involves potential exposure to toxic materials# Any assistance or advice whloh will be instrumental in bringing about such an hygienic program will gladly be given# Signed} K'ADUpeinrptietlvecieertdironsrigPtyhl.y.a.o.sbfioo..Clr1oaigtnoycriynnoafti 0020975