Document YjXVE2q1kxMnaK9EL44Bja3N

TOXICOLOGY [wl. 29, no. j irritation, it seems likely that this Iso be applicable to other pharmaitions both to avoid irritation and orption. By a slight modification f fabrication it may be possible to >unt of drug liberated per unit of Su mma r y blet impregnated with cellulose ilose nitrate has been developed. :$ membranous cellular structure, Ives very slowly and liberates its salt within approximately eighty dissolving impregnated tablet tly less gastrointestinal symptoms mtly used fast dissolving saltt and the formerly used pure salt 3 submitted which shows that the mains of the impregnated tablet / through the gastrointestinal salt contained therein is almost nlated. Il CKNOWLEDGMENTS press our gratitude to Capt. E. G. l)3 USN, who early recognized the mtributions In this field, to Capt. MC), USN, and Drs. J. Murray Pfeiffer for their assistance and suggestions during the course of n, and to those men who although :ive to salt, subjected themschv.4 ital conditions. s ix es ., M. B., Bir r e n , J. E-, Prn% :t e, W. A., Jr ., Co n s o l azio , \V. V... A, L. J.: A comparative study of t!; cn of continuous versus intermit U'".: ' tropical heat, Research Project Xt No. 1, Naval Medical ResearA May, 1945. H.: Critical factors in minimal a ' living spaces. Research Project X t No. 7, Naval Medical Rcsc.\:.> 6 Nov., 1946. ;HE CONTROL OF LEAD EXPOSURE IN STORAGE BATTERY MANUFACTURE* Gr a n t S. Win n 1 a n d Ca r r o l l Sh r o y e r Delco Battery Operations, Mttmie, Indiana ^ URING the past ten years, the program for sary in relation to work in the lead industry. the control of lead exposure of workers at When he reports at his job, his foreman specifically Delco Battery Operations has undergone a points out those potential hazards which must be camber of changes, each change resulting from considered on that particular operation. In attempts to improve working conditions and to struction by various methods continues through :cime the methods of detecting abnormal absorp out the worker's term of employment. It should tion of lead before physical symptoms develop. be noted that one of the most effective means of Originally, only atmospheric contamination was teaching the new employee is through his obser measured by means of "dust checks", L&ter, the vation of and association with the more experi program was expanded to include blood analyses enced employees. ar.d still later urinalyses were introduced. That The position a man may hold in the plant is art adequate control of lead exposure has been determined on the one hand by the results of his maintained is indicated by the fact that in these pre-employment examination and on the other by ten years, only four cases of lead intoxication have the rating of that position as determined by the U*cn reported even though some 300 men are em periodic dust checks. At approximately one ployed in jobs which, with no control, would be month intervals, surveys of the plant are made. hazardous. The success of the program has been The extent to which the atmosphere of workrooms and is in large measure due to the sincere cooper is contaminated'by lead dust is determined at 35- ation of both the management and the employees. 50 points throughout the plant; each type of oper The program at the present time consists of two ation involving the handling of lead is checked. xeueral phases: reduction of air contamination to a Every operation In the plant is thus catalogued as minimum by the application of good engineering to the relative potential hazard to the operator. principles and the early detection of abnormal ab These periodic surveys also serve a second purpose sorption by every means available. The engi in two ways: (a) higher than average dust checks neering phases of the program have been discussed for an individual operation lead to prompt investi h a previous paper and will not be considered here. gation to discover and correct the cause, (b) values At the time a new employee is hired he is subjected consistently over the safe limit lead to the im o a thorough pre-employment examination which provement of engineering control in order to re deludes chest X-ray, blood count, physical exami duce the exposure of the worker. nation and medical history. Evidences of lung, All workers who are employed in potentially Sidney or hepatic disorders as well as poor blood hazardous positions are required to report periodi picture or mouth breathing are prime factors con- cally to the hospital for blood, checks. The tiered in placing the man in positions involving frequency of these checks is determined by the Kork with lead or its compounds. The data ob- relative potential hazard of the position at which 'a:ned in this examination serve the second and the man works and varies from two week intervals dually important function of furnishing a to sixty day intervals. All men, whether working normal" picture for comparison with data col in catalogued positions or not are checked twice a led in later examinations. year. These blood checks include a count for Before assignment to a position in the plant, the stippled erythrocytes, red blood cells and a deter r employee is carefully instructed concerning mination of the percent hemoglobin. The man ; vrsonal hygiene and good health practices neces- weighs himself and is interrogated by the nurse for subjective symptoms. # Received for publication January 15, 1947. A ^per presented at the Ninth Annual Meeting of the y-erican Industrial Hygiene Association, Chicago, V/it 9-11, 1946. , Present address: Winn and Co., Tnc., 405 East South Street, Salt Lake City 2, Utah. As is well known, a poor blood picture, i.e. high stipples, low hemoglobin and red cell count, may result from a number of causes other than lead absorption. Therefore, whenever the blood checks 351 352 JOURNAL OF INDUSTRIAL HYGIENE AND TOXICOLOGY fro/. 20,, indicate an abnormality, or when interrogation indicates any possibility of subjective symptoms, an immediate request is made for the collection of a urine sample. This is either a twelve or twentyfour hour sample collected at home by the mail and analyzed for lead by use of the ditkizone pro cedure. If the urinary output of lead is in the normal range, the medical department investigates further to discover the organic disorder and the man is referred to his family physician for treat ment. A high urinary output of lead is checked by the analysis of a second sample collected as soon and one month on a job entirely removed fr<>: lead. The analytical data accumulated during this h:: year period have yielded information which ha proved useful in controlling lead exposure. ]:: Figure 1 are plotted the time-relationship curv^ j for the average blood counts for 115 men wh, worked more or less continuously over this period. It is apparent that, in general, a close correlates exists between the stippled cell count and the per* cent hemoglobin; it is equally apparent that r.c corresponding relationship exists between then' 5f>M. I.* % zc lie $ 0~ 36 <** i I ,s 9 io If tc 3o X *6 * 15 i io 5 iff. 3 n as possible. Confirmation of the high urinary lead excretion results in prompt action. This action will vary according to the individual case, ranging from investigation and correction of me chanical failures or disregard of good personal hygiene practices to actual removal of the worker to a position of minimum potential exposure. One problem, involving an operation which re mains somewhat hazardous despite repeated at tempts to reduce the exposure by engineering means, has been solved by using alternate work crews. Thus, a crew works one month on this job values and the average of red blood cell comIt thus follows that, at best, the red blood ct count is unreliable evidence for establishing d : existence of excessive absorption of lead. X-' curves clearly reflect a definite improvement * conditions from 1935 to 1940 with maintenance good conditions thereafter, excepting for a backslide during the latter two years of the * This latter variation was due to the very rn; labor turnover, accelerated production and : introduction of new manufacturing processes. In Figure 2 are plotted the time-relation^ Q< k (4> * * *4 DUP050058697 zm AND TOXICOLOGY \voL29$iu , one month on a job entirely removed fo ie analytical data accumulated during this :< period have yielded Information which }.v Del useful in controlling lead exposure. J :e 1 are plotted the time-relationship cum he average blood counts for 115 men wh , ?d more or less continuously over this peri-: i ipparent that. In general, a close correlat.'vr. between the stippled cell count and the pm Hemoglobin; it is equally apparent that bonding relationship exists between Uu*c 4f | 1942 l 1043 l 1944 J 19*5 S(,L 1947) LEAD EXPOSURE IN STORAGE BATTERY MANUFACTURE 353 vorking m lead. the average of red blood cell count* lows that, at best, the red blood m`* nreliable evidence for establishing t-' >f excessive absorption of lead. T-' rly reflect a definite improvement >: 'rom 1935 to 1940 with maintenance dons thereafter, excepting for a &V : uring the latter two years of the wa' variation was due to the very r.u ver, accelerated production and ' t of new manufacturing processes. 2 are plotted the time-relation** DUP050058698 354 JOURNAL OJ? INDUSTRIAL HYGIENE AND TOXICOLOGY [vol, 29} no 5 DUP050058699 ND TOXICOLOGY [vol. 29, no. 5 Sc.pt, 1047) LEAD KXTOSURE IN STORAGE BATTERY MANUFACTURE 355 curves for the concentration of lead dust in the atmosphere of workrooms in the plant. Curve A is a general average of all dust checks taken in the plant. This curve is somewhat misleading, how ever* since two of the operations in the plant, be cause of their nature, have proven difficult to pro- two areas are omitted. The improvement noted after 1942 is ascribed to the installation of new exhaust systems and overall improvement of pro cesses necessary after the introduction of socalled "permanized batteries" which arc composed of charged plates and are of necessity assembled I'1 IS. ' lie ea y l ea o pep l )r ffi UfilNS 76 1 Io { X | k s Ja1 o Tb S - _______ 7 /V " \Aj\ \ V Xp jt a fij % Fig . 6. Atypical blood pictures. tect by exhaust ventilation. They are for this reason, completely Isolated from the rest of the plant and from each other. The workers in these two areas, numbering less than a score of men, are required to wear respirators, A more accurate picture of the actual condition of the plant is in dicated by Curve B which shows the average con tamination of the work room atmosphere if these bone dry. Since this was essentially a war-time product, it is of interest to construct Curve C which omits both the isolated areas previously mentioned and also operations involving permanized plates. In other words, Curve C represents the conditions in the plant under normal circum stances. On the basis of this curve, and consider ing the record achieved in the past ten years, it is DUP050058700 356 JOURNAL OF INDUSTRIAL HYGIENE AND TOXICOLOGY [vol. 29, *. 5 considered that the maintenance of an average of no more than 5 mg. of lead per 10 cubic meters of air, with the proper function of the additional program outlined, assures adequate control of the lead hazard. The presently accepted safe limit for the concentration of lead in work room air is admittedly a desirable goal, but a higher concen tration can be safety tolerated when accompanied by a supplementary program such as the one out lined above. It will be noted that the dust checks as shown in this curve are in general agreement with the data for blood counts. Since urine samples were analyzed only in cases of suspected abnormal lead absorption, the data from these do not portray the average of all of the exposed workers, but a value probably considerably higher. Consequently, from these data it is not possible to correlate urinalyses with dust checks and blood counts. However, it has been possible, as indicated in Figure 3, to set up approximate maximum limits for the rate of urinary excretion of lead, beyond which transfer of the worker is ad visable. Experience at this plant has led to the following conclusions: (a) 0-150 micrograms of lead per liter of urine is the "normal" range for men working under conditions of controlled industrial exposure; (b) the range from 150-250 micrograms of lead per liter of urine is abnormal for industrially exposed workers and in such cases the involved workers should be kept under observation until the cause is found and corrected; (c) whenever the urinary excretion exceeds 250 micrograms per liter, im mediate steps should be taken to reduce the lead intake--usually the man is transferred to\a po sition of minimum exposure until the cause of the abnormality is discovered and corrected. It should be emphasized that a diagnosis of dangerous lead absorption cannot be made upon the basis of any one type of data. This is illus trated by a number of case histories from our files. Figure 4 shows the typical picture expected in cases of excessive absorption, i.e. increased stippling and urinary excretion with concurrent drop in percent hemoglobin and red blood count. However, atypical cases, in which is found every possible variation, are of frequent occurrence. This is illustrated in Figure 5 by the following examples: CASE URINE STIPPLES HB. EKB......... High AG.............. Mod. CB........... . High WRH............. High RB.............. . Low Mod. High Mod. High High High Low Mod. Mod. Mod. S.B.C. High Mod. Low Mod, Low The last two cases, shown in Figure 6, are of particular interest since both were diagnosed as cases of lead intoxication by local physicians although obviously these data do not substantiate such a diagnosis. It is not intended to imply that the program out lined is perfect, nor that it cannot be improved. As it has been changed frequently in the past, so we expect to continue making changes in order to in corporate new methods and improve old ones. t 0 l I c c C t c c ti s< tl tc ir. re rii A in dt ra ki > ; b' ; t;o > r.j y cr. h: DUP050058701