Document QXQdEyK1kr1vXe4ak8JG8goG8

io TWi tnoHrtol ha* i*cmduc*d with permission <* fh# copyright wnf. Furh-if reproduction Is prohibitsJ DEFENDANT'S EXHIBIT PUBLIC HEALTH REPORTS vol. no JAJfUAHY 4, 1936 NO. 1 EFFECTS OF THE INHAEAT10N OF ASBESTOS DUST ON THE LUNGS OF* ASBESTOS WORKERS - A Preliminary Study By A. J.Lanza, AttielatU Medical Director, William J. McConnell, Attitlant Medical Director, and J. \WitUAM Fekkel, CfiemiU, Metropolitan Lift Insurance Co. INfXTtODUCTION In 1929 the Metropolitan Life Insurance Co. was approached by officials representing the ashes -tos industry in the United States, who were, clesirons of ascertaining 'whether asbestos dust was an occupa tional hazard in their establishments and, if so, what was the naturo of this hazard and what should be done to prevent or control it. About this time several articles hod appeared in English medical, journals describing a pneumoconiosis duo to asbestos dust. While in one or two isolated instances tlbe occurrence of this type of pneumo coniosis had been described in American journals, the industry itself appeared to be quite uninformed of tho existence of any such occupational disease. The hazard of silica duBt, with special reference to the lungs, has long been appreciated, and a great deal of Btudy and research has been applied to the problem (in the metal mining and certain other industries) in Great Britain, tho United States, the British Do minions, and in other countries. The nature of the effects of Bilica dust expressed in tho term "silicosis", with the resultant extraor dinary predisposition to pulmonary tuberculosis, is well known. These effects' have been associated with the inhalation of dust con taining free silica in varying ramounts. The effects upon the pul monary tissue of dusts containing combined silica--silicates--are still a fertile field for investigation, but evidence is accumulating that certain of these dusts produce pathological results quite distinat from true silicosis. ' The aame "asbestosis" has been applied to the pneumoconiosis caused by asbestos dust and it will bo so used in this report. Chem ically, tie asbestos of commerce is a hydrated magnesium silicate consisting primarily of silica (combinod silica) 44.1 percent, mag nesia 43.percent, and water 12.9 percent, while ferrous iron and nickol axe present in small quantities. This commorcial varioty of 101054'--3s-- Li. SC-ALL-01005 SCF-FA-0265 7too*rr 4. IU3 . 2 asbestos most commonly encountered is designated as chryBotfle and is one of the four varieties of the mineral serpentine, in which it usually occurs in seams. It should be borne in mind that silicosis (and presumably asbes- tosifl) develops very slowly, taking from 5 to 15 and even 20 or 25 years to become established. This rate of progress is influenced mainly by the dosage of silica which the lungs receive, and this dos age, in turn, depends upon three variables--the amount of silica in the dust, the quantity of dust in the air, and the length of exposure. Individual idiosyncrasy might be included as a fourth variable; however, little is known of the variations in susceptibility in tboso exposed to dust. It might well be assumed that similar variables would influence the occurrence of ssbestosis. - In places where asbestos is mined or fabricated in North America there does not appear to be present the clear-cut clinical picture which is so unescapable in communities with a true silicosis hazard, such as hard-rock mining communities. It may be that some of tho asbestos plants are of too recent origin for tho typical effects of a silicate dust to become manifest, but this would not apply to tho older mines or to all of the fabricating plants. The industrial health service of the Metropolitan Life Insurance Co. undertook the following investigation during the period from October 1929 to January 1931, which included: 1. A study of dust conditions in asbestos mines and mills in Canada and in fabricating plants along the Atlantic Seaboard in the United States. . 2. Physical examinations of asbestos workers, including X-ray films. 3. A study of dust exhaust systems designed to eliminate asbestos dust. Data on the fabricating plants only are included in this study and are designated in the report as plants A, B, C, D, and E. This is a preliminary report. A more extensive study of the asbestos industry is now under way. OUST STUDIES Apparatus and methods of sampling.--Both tho impingor (1) and the electric precipitator (2) were used for the collection of air samples for dusts at the breathing levels and in close proximity to the workmen. Both of these formB of apparatus ore adapted for this work, as thoy are transportable, easily set up and adjusted for tho taking of tho air samples at the proper level, and are extremoly olficiont. The impinger collects the dust by aspirating the air and then impinging it onto a flat surfaco covorod by a liquid in a container. The liquid used was distilled water, containing 50 percent alcohol to 2 encountered is designated as chrysotile and ties of the mineral serpentine, in which it ; ; mind that silicosis (and presumably asbesIv, taking from 5 to 15 and even 20 or 25 shed. This rate of progress is influenced silica which the lungs receive, and this doson three variables--the amount of silica in dust in the air, and the length of exposure, might be included as a fourth variable; of the variations in susceptibility in those ght well be assumed that similar variables rence of asbestosis. os is mined or fabricated^ in North America o be present the clear-cut clinical picturo in communities witli' 6? true silicosis hazard, . communities. It may-be'that some of the >o recent origin for'the'typical effects of a manifest, but this would not apply to the ;ic fabricating plants:; : service of the Metropolitan Life Insurance wing investigation';'during the period from 1931, which included: ' ' ' litions in asbestos mines and mills in Canada along the Atlantic Seaboard in the United ' jns of asbestos workers, including X-ray aust systems designed to eliminate asbestos ' ' ' ''1 . . ' ' g plants only are included in this study and ort as plants A, B, C, D, and E. This is a iore extensive study of the asbestos industry . 1 . i , " s*'*TTTbi ft 11 VT*V" DUST STUDIES 'n *; J " ` ! of sampling.--Both the impinger (1) and 2) were used for thdiebllection of air samples ' levels and in close proximity to the workmen. ypnratus are adapted for this work, as they set up and adjuste'ct for tho taking of the level, and are extfemelyTcfficient. the dust by aspirating1 the air and then surface covered by a'UiqilUfiiia container. lied water, containing 50 percent alcohol to . ` ' . * j ;* 3 ,January 4 1035 prevent the solution of some of the dusts, particularly any silica which might be present. The impinger was actuated by an electri cally driven rotary pump and the rate of air sampled was measured by means of a resistance type of flow meter with an inclined manome ter for measuring the pressure difference. Each sample represents the dust collected from a volume of 100 cubic feet of air. The electric precipitator is designed upon the Cottrell precipitator principle used for recovering dusts and fumes commercially. This principle depends on electrifying the dust particles by making them pass through an electrostatic field and thus causing them to settle out upon a sheet of celluloid. The electrostatic field is set up by means of a transformer operating from the lighting lines on 120 volts, alternating current. Air is drawn through the apparatus by a small rotary fan, run by a motor, the quantity being measured by a flow meter. Samples of dust brushed from beams and pipe lines near the ceiling also were secured for chemical analysis. All samples were shipped to the industrial hygiene laboratory of the Metropolitan Co., and the dust counts were made according to the methods accepted by the United States Bureau of Mines and the United States Public Health Service (1). Particles in size up to 360 microns in the greatest diameter were counted. Chemical analyses were made for total (free and combined) silica according to the accepted standard method of Hillebrand (3). In the first plant studied (A) only particles 10 microns and under in size were counted. It has been demonstrated repeatedly that no silica particles exceeding 10 microns (a micron equals one-millionth part of a meter or one-thousandth part of a millimeter) in greatest diameter enter the lung tissu ; for this reason, the larger particles usually are not considered when determining dust counts. Later, as it appeared from some of the published articles (4) (English) that asbestos particles much larger in size were found in lung tissue, it was decided to count all particles and make differential counts of all those 10 microns and under.1 Total particles per cubic foot and the corresponding weight of the dust in milligrams were obtained. Since no relationship between the dust counts and the corresponding weights was found, the weights are not included in the tabulations in tliis report.' Table 1 shows by plants and by departments the maximum and minimum dust counts in million particles per cubic foot of ah'. Although the counts in plant A are of particles 10 microns and under, 1 Samples collected by both the Impinger and the electric precipitator were counted, In addition, microphotographs of these dost particles were enlarged by being projected upon a screen with a lantern wide projector, tbo enlarged particles being measured with a ruler. Knowing the entire enlargement (by actual measurement), it was easy to calculate the original particle she (5). By the use of Daren's (fl) ogaiithmlc probability paper, the logarithms of the function to be measured (In this case microns) are P otted as ordinates against the probability of occurrence as abscissae. /'anuary 4, 1034 4 and in the other plants are for all particles, direct comparison is possible, as in no sample taken were the number of particles 10 microns and under less than 94 percent of the whole. Table 1.--Maximum and minimum dust counts in million particles per cubic foot of air, by plant and department Plant A Plant B riant 0 Plant D Plant E Department Million Num Num ber of Sara- pies taken parti cles under 10#* per cubic toot of Num ber of sam ples taken Million parti cles per cubic loot of air Num ber ol sam ples taken Million parti cles per cubic foot of air Num ber of sam ples taken Million ber of para sam des per ples cubic per foot of cubic air foot of Million para des per cubic foot of air air air Mule spinning.............. Twisting--.............. ...... Molded brake band s W-IM 3 H-1M 9 6 n 2 M- M KSH2 10 4 ....... !. Mo-2 4 h-i $H G 3 H-t 8 2 -43 ............ 3 8 -- ............ 6 3M-I0 '"'is' I -7 2 M- M 1 Included in spinning. * Includes broad loom weaving. 3 30 -82 3 2G -70 IT 10M-10JS Whereas the dust in the preparation room is practically all duo to asbestos, the contrary is the case in the other departments. In the carding, spinning, and weaving rooms asbestos comprises about 25 percent of the material used. On special jobs the percentage of asbestos may be higher, but in general the figure quoted is approxi mately correct, the other material consisting principally of cotton. In the insulating departments of plant A, asbestos is but 5 percent of the total material used. In the molded brake-lining and clutch division of plant D, asbestos comprises about 25 percent of the total material. The actual exposure to asbestos dust, therefore, is consid erably less than is indicated in the dust counts in table 1. CONDITIONS IN THE PLANTS The processes in these plants were very similar to thoso in cotton mills in general. For illustration, the process in the preparation room of plant B is here detailed at length: Asbestos is received in bogs. These are emptied upon the floor and the asbestos is shoveled into pug mills and run for about 5 minutes in order to crush and open the fibers. From there the asbestos is shoveled into trucks and wheeled to hoppers with either horizontal or vertical openers, similar to those used in textile mills. After passing through the opener, the material is discharged into trucks. Waste manufacturing material is first run through a garnet machine and discharged into trucks, which are material is fed into these in the sai After being discharged from the o vibrating or shaking screen, where a suction hood and blown into a The short fibers falling through th< used in making an asbestos cement The cotton is received in bales vertical openers. It is discharged ii the vertical and horizontal opene; fiber, the cotton, or the waste mate bins. As needed, these materials o floor in proportion to the mixture materials are then passed through : is discharged from the picker, it is The material is then taken by a m< bin in the card room. Two of tlu this conveyor system, while a th: suction device which conveys the card room. The object of the two s? of two grades of material at the s; not equipped with an oil spray. 1 marily to entrap the small asbesto; in the cotton fiber throughout the p weaving. Incidentally, it is appn amount of dust. The material is s oil at this point; but by the time ; diminished to less than 1 percent. While mineral oil was used in tin apparently was not as efficacious ns not used, nor was there any uttemp of dust exhausting. Carding machir. there was a humidifying, ventilat plant B depended on natural hun machines were equipped with a dus efficiently used. In plant C cardii which was equipped with an air-ct buildings the machines had exhaust Two plants, B and C, had artifici Bpinning rooms. In the former the humidity 78 percent. One plant, C the twisting department and also in the relative humidity was 76 percen 69 F., as compared with a relative weaving room of plant A. re for all particles, direct comparison is taken were the number of particles 10 m 94 percent of the whole. r.um du.it counts in million particles per cubic foot by plant and department Plant B Plant C Plant D Plant E Num \'um'vr of turn* rd.CS ..ikeo Million pani cles per cubic /out of air Num ber of sam ples taken Million parti cles per cubic foot of air Num ber of sam ples taken Million ber of parti sam cles per ples cubic per foot of cubic air foot of Million parti cles per cubio foot of air air 9 1-6-8 5 5 w 4 14- n 8 2 H3 6 3M-ISM 3 8 U - 394 6 394-10 15 I -7 3 30 -*2 3 26 -76 3 Mi-10 7 3 2 H- H < Includes broad loom weaving. preparation room is practically all due to he case in the other departments. In the aving rooms asbestos comprises about 25 >sed. On special jobs the percentage of at in general the figure quoted is approximaterial consisting principally of cotton, cats of plant A, asbestos is but 5 percent . In the molded brake-lining and clutch os comprises about 25 percent of the total isure to asbestos dust, therefore, is considd in the dust counts in table 1. TIOXS IN THE PLANTS >lants were very similar to those in cotton ration, tho process in the preparation room at length: ags. These are emptied upon the floor and ito pug mills and run for about 5 minutes n the fibers. From there the asbestos is wheeled to hoppers with either horizontal to those used in textile mills. After passing naterini is discharged into trucks. Waste - first run through a garnet machine and discharged into trucks, which aro wheeled to the openers, and the material is fed into these in the same manner as is the new material. After being discharged from the opener, the material is put onto a vibrating or shaking screen, where the long fibers are picked off by a suction hood and blown into a bin to be used again in textiles. The short fibers falling through the screen are either sold as such or used in making an asbestos cement. The cotton is received in bales, opened, and also run through vertical openers. It is discharged into trucks. The filled trucks from the vertical and horizontal openers containing either the asbestos fiber, the cotton, or tho waste material are taken to separate storage bins. As needed, these materials are weighed and, dumped onto the floor in proportion to tho mixture desired, and the resulting mixed materials are then passed through a mixing picker. As this mixture is discharged from tho picker, it is sprayed with a light mineral oil. The material is then taken by a mechanical conveyor to the storage bin in the card room. Two of these mixing pickers discharge onto this conveyor system, while a third machine is equipped with a suction device which conveys tho material to a storage bin in tho card room. The object of the two systems is to facilitate the handling of two grades of material at the same time. The third machine is not equipped with an oil spray. The object of the oil spray is pri marily to entrap tho small asbestos fibers and hold them enmeshed in the cotton fiber throughout the processes of carding, spinning, and weaving. Incidentally, it is apparent that it also diminishes tho amount of dust. The material is saturated with about 4 percent of oil at this point; but by tho time it reaches the looms, the oil had diminished to less than 1 percent. While mineral oil was used in the preparation room of plant C, it apparently was not as efficacious as in plant B. In plant E oil was not used, nor was there any attempt at humidification or any system of dust exhausting. Carding machines were fed by hand. In plant A there was a humidifying, ventilating, and heating system, whilo plant B depended on natural humidity. In plant E the carding machines were equipped with a dust-exhaust system, but it was not efficiently used. In plant C carding was done in 2 buildings, 1 of which was equipped with an air-conditioning system, and in both buildings the machines had exhaust equipment. Two plants, B and C, had artificial humidity installations in their spinning rooms. In the former tho temperature was 76 F., relative humidity 7S percent. One plant, C, had a humidification system in the twisting department and also in the weaving department, where the relative humidity was 76 percent with a dry-bulb temperature of 69 F., as compared with a relative humidity of 44 percent in the weaving room of plant A. V > January i, 1935 6 Aside from plant E, it would appear that the dust hazard was not excessive except in the preparation rooms of plants B and C. The dust counts are interesting, too, when considered in the light of the permissible standard for granite dust, established by the United States Public Health Service (7), namely, about 10 million particles (10 microns and under) per cubic foot. However, we are not justified in assuming that because available information suggests that asbestosis is a milder disease clinically than silicosis, the threshold of permissible dust counts is higher. Asbestosis appears to be patho logically different from silicosis, and the experience so far does not warrant an attempt to define a standard of dustiness for asbestos dust. DOST CONTROL Various measures, such as oiling, humidification, and local exhausts, tended to reduce the dust. Nevertheless, it was evident that they were only partly successful. If it is expected to control dustiness in these plants, final reliance must rest upon properly constructed exhaust equipment. In plant C in one department an experimental installa tion was set up. In spite of some obvious faults, this equipment, on the basis of comparative dust counts, reduced the dust by 50 percent and with further alterations will probably be 75 percent effective. In this case such a reduction seemed quite satisfactory. It is neither practicable nor economically desirable to install such equipment as will make the air entirely dust free. The normal defensive mechanism of the body tnkes care of a fair amount of atmospheric pollution. It is when the body is exposed to an excessive amount of dust that tliis defense mechanism breaks down. The application of exhaust equipment to textile machinery involves considerable difficulty, especially where the construction of the plant is such that it is not possible to apply down-draft suction to the looms, It is desirable to install exhaust apparatus in any plant on an ex perimental basis first, and then check its efficiency by dust counts. This practice will result in saving a needless expenditure of money, PHYSICAL EXAMINATIONS X-ray films were made of 126 persons (108 men, 18 women) working in asbestos plants in the United States. All but five of these wore given physical examination. The cases were selected more or less at random from among those having more than 3 years of employ ment in the industry. It wa3 soon obvious that the early diagnosis of asbestosis must rest to a large extent on X-ray pictures of the chest. As in the early stages of silicosis, the clinical symptoms of the asbestos workers were usually indefinite and inconclusive. The interpretations of these films are based on the readings of one com petent roentgenologist, but they have been reviewed by several others experienced in this field, a minor nature, and there was gr The films were read conservat'm examination and the age of tl positive only when there was no were guided by their experience moconiosos. The films classed a; subdivided into doubtful anc whether the individuals classed r. definite asbestosis. Particular at or absence of indications of tubi reviewers of the films were in ae< of silicosis in mind, it was felt i devoted to ascertaining, if possi disposes to tuberculous infection. . The cases of asbestosis were < and second stage. The first st X-ray examination definite lun;. warrant a diagnosis of pneumoi symptoms. The second-stage < pathology and also definite'svmp All these individuals 2 were act it was not practicable to make an. ability or disability. Had any in extensive pulmonary involvemei or total disability, they would 1 but no such cases were found. Of the total of 126 X-rny c: second-degree asbestosis, 03 as fir negative. There is a definite increase in t in relation to the years of expo numbers make it impossible to d enters into this increase. Table 2.--Classifica'i Years of exposure Over 15 years...'......... )D to 15 years........... 5 to 10 years............... . Voder 5 years............ . '' Total examined. < Part time. 1 One asbestos worker (sooond stage) retired of his to tbb study, but is still active about his garden. 6 could appear that the dust hazard was not operation rooms of plants B and C. The x, too, when considered in the light of the granite dust, established by the United ice (7), namely, about 10 million particles r cubic foot. However, we are not justified available information suggests that asbesclinically than silicosis, the threshold of liigher. Asbestosis appears to be patholicosis, and the experience so far does not efine a standard of dustiness for asbestos DUST CONTROL is oiling, humidification, and local exhausts, t. Nevertheless, it was evident that they ll. If it is expected to control dustiness in must rest upon properly constructed exhaust n one department an experimental installa of some obvious faults, this equipment, on lust counts, reduced the dust by 50 percent ons will probably bo 75 percent effective, ion seemed quite satisfactory. It is neither illy desirable to install such equipment as lust free. The normal defensive mechanism a fair amount of atmospheric pollution. It od to an excessive amount of dust that this ; down. ust equipment to textile machinery involves iccially where the construction of the plant ile to apply down-draft suction to the looms. . exhaust apparatus in any plant on an ex1 then check its efficiency by dust counts, n saving a needless expenditure of money. SICAL EXAMINATIONS d 12G persons (108 men, 18 women) working United States. All but five of these were hi. The cases were selected more or less hose having more than 3 years of employwas soon obvious that the early diagnosis i a large extent on X-ray pictures of the iages of silicosis, the clinical symptoms of usually indefinite and inconclusive. The !ms are based on the readings of one comut they have been reviewed by several 7 January i, 1039 others experienced in this field. The differences of opinion were of a minor nature, and there was general agreement as to interpretation. The films were read conservatively, taking into account the physical examination and the age of the individual, and were classed as positive only when there was no major disagreement. All examiners were guided by their experience in silicosis and other types of pneu moconioses. The films classed as negative for asbestosis were further subdivided into doubtful and negative. Only time can tell whether the individuals classed as doubtful are progressing toward a definite asbestosis. Particular attention was focussed on the presence or absence of indications of tuberculosis, and in this respect all the reviewers of the films were in accord. With the unhappy experience of silicosis in mind, it was felt that a great deal of care should bo devoted to ascertaining, if possible, whether or not asbestosis pre disposes to tuberculous infection. The cases of asbestosis were divided into two classes, first stage and second stage. The first stage embraces those who show by X-ray examination definite lung pathology sufficient in extent to warrant a diagnosis of pneumoconiosis, but who have no definite symptoms. The second-stage cases exhibit more extensive lung pathology and also definite symptoms. All. those individuals 2 were actively engaged in factory work, and it was not practicable to make any distinction on the basis of working ability or disability. Had any individuals been found who exhibited extensive pulmonary involvement and marked physical disability or total disability, they would have been classified as third stage, but no such cases were found. Of the total of 12(3 X-ray examinations, 4 were diagnosed as second-degree asbestosis, 03 as first degree, 39 as doubtful, and 20 as negative. There is a definite increase in the percentage diagnosed as positive in relation to the years of exposure, as shown in table 2. Small numbers make it impossible to determine how far the factor of age enters into this increase. . Tabi.k 2.--Classification of cases by years of exposure Years of exposure Percentage positive Positive Number Doubt ful Negative 87 13 11 68 7 3 60 30 23 43 17 10 07 39 <3 2 3 12 20 i Part time. * 1 not continuous. * One asbestos worker (second stace) retired of his oven accord, because of old age, 10 rears previous to this study, but is stiil active about his garden. ?:;w vi: : I r,; ! j 'p $! . i ji :| January 4. 1999 8 Of the 64 persons given physical examination and diagnosed aa having positive asbestosis, only 8 were entirely freo from symptoms, while 10 out of 37 with doubtful and 7 out of 20 with negative diag noses were free from symptoms. Dyspnoea and cough wore the symptoms most complained of, but none of these cases exhibited the urgent or evident type of "short wind" seen in true silicosis. Several of those classed as negative stated that they were "short winded" and were so recorded, but too much emphasis should not be placed on statements of subjective symptoms. During the progress of the study, physicians who were practicing in the communities where asbestos workers lived were questioned and stated that they did not find an unusual amount of tuberculosis among these workers. The contrast between this state of affairs and that found in a community with a silicosis hazard is noteworthy. The incidence of tuberculosis (based upon X-ray films) is given in table 3; 40 of the 67 examined had less than 15 years of employ ment in the industry. Table 3.--Incidence oj tuberculosis Positive Doubtful Negative Tuberculosis (bealed).......... ....................................,,..................... . Tuberculosis (active)...................................................... ...................... Total exitininod............... -..........,....................... .................................. 7 >1 67 1 0 39 2 l 20 x This case was diagnosed ns probably active on tho X-ray findings. Table 4 gives information as to physical signs of chest trouble. Table 4.--Chest findings Positive Doubtful Negative Total................... .......................................................................... 1 33 31 3 67 *9 7& 39 *7 20 1 A t least 6 of the53 showed no evidence associated with nsbestosis. * 2 of these not associated with usual signs found with asbestosis. ' 0 of these not associated with usual signs of asbestosis. What significance, if any, can be attached to the presenco of "asbestos corns" on the hands of workers appears doubtful, as IS percent of the positives (12 out of 64) and 15 percent of the others (doubtful, 7 out of 37, negative, 2 out of 20) showed such corns. Each roentgenologist who reviewed the X-ray films called attention to the fact that these films indicated a very unusual incidence of enlargement of the heyirt. It is probable that this is a compensatory enlargement due to the additional work put upon tho heart in efforts to pump blood through the fibro sufficient attention has been paid t upon the heart. Many workers had changed fro from one plant to another during asbestos industry. Since only th time of this survey in the variou no way of knowing tho average . inhaled by these people over the } quently, it is not possible to corr amounts of dust exposure. INSUHANi To throw light on the relations nary tuberculosis, an analysis of manent disability claims was mat group insurance and having avail) There were 2,099 lives involved years. The death claims are so elusions cannot be reached from a same is true of tho sickness cla: number of claims for respiratory < studied but low for the others, a experience of 1927. However, du first part of 1929 there was an epi< The records of ono establishm,death claims and 8 of 10 permam listed as due to pulmonary tuberc ordinate amount of tuberculosis fi the employees were Negroes, and ally high in this section of the c> diagnosing pneumoconiosis and tuberculosis, these claims were sti who had treated the individuals and sanatorium records, inclue investigated, with the following ri Death claims: 1. A typist, not exposed intestinal tuberculosis. . 2. Colored male, age 27; months; died of pulmonary f. was in sanatorium 10 mom! mann. No evidence of asbe. 3. Colored male, age 32; w 7 months; died of pulmon; hospital. Cavitation both lu nation and diagnosed as rely free from symptoms, of 20 with negative diagiea and cough wore the these cases exhibited the . in true silicosis. Several ey were "short winded" aais should not be placed uring the progress of the the communities where stated that they dUd not tong these workers.. The tat found in a community q X-ray films) is given in ban 15 years of exsploy- tigns of chest trouble. FoolUvo Doubtful Shfatlro n 11 -a J. 9 38 2 7 U 0 cbed to the presonce of : appears doubtful*, os 18 15 percont of the others i) showed such corns. -ray fllms called attention a>T jiisual incidence of )(' is a compensatory up> he heart in efforts . 0. haaarji, UW to pump blood through the fibrosed lungs. It is possible that not sufficient attention has been paid to the effects of the pneumoconioses upon the heart. Many workers had changed from one department to another and from one plant to another during their years of employment in the asbestos industry. Since only the amounts of dust collected at the time of this survey in the various departments are known, there is no way of knowing the average amount of dust in the atmosphere inhaled by these people over the years of their employment. Conse quently, it is not possible to correlate individual cases with definite amounts of dust exposure. . . INSURANCE CLAIMS To throw light on the relationship between asbestosis and pulmo nary tuberculosis, an analysis of death claims and total and per manent disability claims was made in regard to companies carrying group insurance and having available figures. There were 2,099 lives involved, with a total exposure of 7,019 lifeyears. Tho death claims are so small in number that reliable con clusions cannot be reached from any subdivision of the figures. The same is true of tho sickness claims undor health insurance. The number of claims for respiratory diseases is high in two of the plants studied but low for the others, as compared with the Metropolitan experience of 1927. However, during the latter part of 1928 and the first part of 1929 there was an epidemic of infiuonza. The records of one establishment (plant B) showod that 6 of 36 death claims and .8 of 10 permanent and total disability claims were listed as due to pulmonaiy tuberculosis. This appeared to be an in ordinate amount of tuberculosis from this plant.' However, many of the employees were Negroes, and also tuberculosis claims are gener ally high in this section of the country. Realizing the difficulty in diagnosing pneumoconiosis and the tendency to confuse it with tuberculosis, these claims were studied individually. The physicians who had treated the individuals were interviewed, and the hospital and sanatorium records, including available X-ray films, were investigated, with the following results: Death claims:# 1. A typist, not exposed to dust; died of pulmonary and intestinal tuberculosis. 2. Colored mole, age 27; worked in asbestos 1 year and 8 months; died of pulmonary tuberculosis following a hemorrhage; was in sanatorium 10 months. ^ Also had a four plus Wassermann. No evidence of asbestosis. 3. Colored male, age 32; worked in asbestos plant 1 year and 7 months; died of pulmonary tuberoulosis alter 1 month in hospital. Cavitation both lungs; no evidence of asbestosis. I iHl c- \v h iV': l H 10 4. Colored male, ago 34; worked in asbestos plant 2 years and 6 months. His physician believes this was a case of uncom plicated tuberculosis. Was not inmate of hospital or sanatorium. No information could bo obtained on the other two cases. Total and permanent disability claims: 1. Male, employed in asbestos plant 3 years. His physician states that he first came under his observation with an old estab lished case of tuberculosis about '2 years after asbestos employ ment started. Also had tuberculosis of the kidney and cervical glands. 2. Male, employed in asbestos plant 8 months. His physician states finding of old fibroid tuberculosis with tubercle bacilli in sputum. No X-ray available; but according to physician, as bestos bodies were found in sputum. * 3. Male, 10 years' employment. Two physicians who treated him at different times are now inclined to believe this man is not tuberculous, but has asbestosis. 4. White male, was reexamined at time of investigation. His physician reports wrell nourished, husky looking, good color, no cyanosis; no clubbing of fingers; diminished expansion; incessant cough; X-ray shows fine mottling disseminated through both lungs. No evidence of tuberculosis. Probably a second stage asbestosis. 5. White male, 13 years in asbestos plant. Is now in sanato rium. An interesting case, His physician states that he has ex tensive asbestosis and pulmonary tuberculosis; cavity in right lung; sputum loaded with tubercle bacilli and asbestos bodies; believes tuberculosis long antedated asbestosis. This patient is progressing in a satisfactory manner. It was not possible to locate the other three cases of total and permanent disability who had been diagnosed as having pulmonary tuberculosis. On the basis of the information obtained, the deaths in death-claims cases appear to be due to uncomplicated tuberculosis; three of them were Negroes, who were probably tuberculous at the time their employment in the asbestos plant commenced. Of the 8 disability claim cases, 1 was uncomplicated tuberculosis and 2 were uncomplicated asbestosis who wero put on disability because of a mistaken diagnosis of tuberculosis. In this same com munity we know of one death due to uncomplicated asbestosis in an individual with many years' employment in the industry.3 CONCLUSIONS 1. Prolonged exposure to asbestos dust caused a pulmonary fibrosis of a type different from silicosis and demonstrable on X-ray films. Clinically, from t-liis study, it appears to be of a type milder than silicosis. . 2. Cases of definite cardiac enlargement were frequently found to be associated with asbestosis. * Personal communication. 3. A predisposition to tuben indicated in this study. 4. Asbestosis as observed in t marked disability in any case, 5. It is not known how much of pneumonia and acute nontut 6. It is not practicable as yet I dust content of air. 7. Tho amount of dust in the . bo substantially reduced. BECOMi It is recommended-- 1. That the industry seriously asbestos plants. 2. That new employees be ex examination of tho chest, and rc. tuberculosis or pneumoconiosis. 3. That employees be examine but at least every 2 years, thi^ examination of the chest. 4. That the industry sponsor s as well as studies on effects of asb ACKNOWI The authors wish to express tl aided in making this study possi ployees of the asbestos companies and gave every facility for securir. University of Pennsylvania, for 1 interpreting X-ray films, and to L States Public Health Service, sun. Bureau of Mines Cooperative Ci pretation of all the X-ray films lis precintion is also expressed to Dr. Lynch, of Charleston, S. C., for in as to the pathology of asbestosis;4 S. C.; to Dr. Joseph H. Wyatt, Fellows, of New York, for assist!' Dr. Paul 0. Snoke, of Lancaster, Danville, Quebec, Canada; and to E. Cummings, of the Saranac Lab study of the pathological effects < Asbestosis bodies In sputum and lung. By Kenn Jour. Am. Med. Assoa., Aug. 80.1930, vol. 95, no. 9, j 10 age 34; worked in asbestos plant 2 years and ysician believes this was a cose of uncom- Was not inmate of hospital or sanatorium, :ld be obtained on the other two cases. i.sability claims: cl in asbestos plant 3 years. His physician ame under his observation with an old estabeulosis about 2 years after asbestos employhad tuberculosis of the kidney and cervical j j ' j : : ; i in asbestos plant 8 months. His physician fibroid tuberculosis with tubercle bacilli in available; but according to physician, asound in sputum. ' employment. Two physicians who treated s are now inclined to believe this man is not asbestosis. s reexamined at time of investigation. His 11 nourished, husky looking, good color, no ? of fingers; diminished expansion; incessant ; fine mottling disseminated through both of tuberculosis. Probably a second stage ; years in asbestos plant. Is now in sanator case. His physician states that he has exid pulmonary tuberculosis; cavity in right with tubercle bacilli and asbestos bodies; long antedated asbestosis. This patient is factory manner. locate the other three cases of total and had been diagnosed os having pulmonary s of the information obtained, the deaths in to be due to uncomplicated tuberculosis; ics, who were probably tuberculous at the the asbestos plant commenced. n cases, 1 was uncomplicated tuberculosis d asbestosis who were put on disability gnosis of tuberculosis. In this same comatli due to uncomplicated asbestosis in an s' employment in the industry.3 conclusions . i ' j i 1 j \ | asbestos dust caused a pulmonary fibrosis licosis and demonstrable on X-ray films, , it appears to bo of type milder than I j ' iac enlargement were frequently found to j is. j 11 fonoaryiUU . 3. A predisposition to tuberculosis due to asbestos dust was not indicated in this study. 4. Asbestosis as observed in this series of cases had not resulted in marked disability in any case. 5. It is not known how much asbestosis may add to the mortality of pneumonia and acute nontuberculous pulmonary infections. 0. It is not practicable as yet to establish standards for the asbestos dust content of air. 7. The amount of dust in the air in the asbestos plants studied can be substantially reduced. . RECOMMENDATIONS It is recommended-- 1. That the industry seriously face the problem of dust control in asbestos plants. 2. That now employees be examined physically, including X-ray examination of the chest, and rejected for employment if they show tuberculosis or pneumoconiosis. 3. That employees be examined physically, preferably every year, but at least every 2 years, this examination to include an X-ray examination of the chest. 4. That the industry sponsor studies on known cases of asbestosis, ns well as studies on effects of asbestosis on the heart and circulation. ACKNOWLEDGMENTS The authors wish to express their sincere thanks to all those who aided in making this study possible, especially the officials and em ployees of the asbestos companies who cooperated to the fullest extent and gave every facility for securing data; also to Dr. Pancoast, of the University of Pennsylvania, for his interest and valuable advice in interpreting X-ray films, and to Dr. F. V. Meriwether, of the United States Public Health Service, surgeon in charge of the United States Bureau of Mines Cooperative Clinic in Picher, Olda., whose inter pretation of all the X-ray films listed in this report is followed. Ap preciation is also expressed to Dr. W. Atmor Smith, and Dr. Kenneth Lynch, of Charleston, S. C., for information and advice, particularly as to tho pathology of asbestosis;4 to Dr. W. W. Wild, of Charleston, S- C.; to Dr. Joseph H. Wyatt, of Newark, N. J., and Dr. H. H. hollows, of New York, for assisting in interpreting X-ray films; to Dt-. Paul 0. Snokc, of Lancaster, Pa.; to Dr. It. H. Stevenson, of Danville, Quebec, Canada; and to Dr. L. U. Gardner and Mr. Donald L. Cummings, of the Saranac Laboratory, who have undertaken the study of the pathological effects of the inhalation of asbestos dust* * Ashostusls boiltos in sputum nod lung. By Kenneth M. Lynch, M, D-, ond W, Atmar Smith, M. D. Jour- Med. Aasoc., Aug, 30,1930, vol, 65, no. 9, pp. 659-661. auuitf7 W35 12 , through animal experimentation, with the aid of a grant from the , t Metropolitan Life Insurance Co. REFERENCES (1) Greenburg, Leonard, and Bloomfield, J. J.: The Implnger dust sampling ap paratus as used, by the United States Public Health Service. Pub. Health Rep., vol. 47, no. 12, Mar. 18, 1932. Reprint no. 1828. (2) Drinker, PhUip, and Thomson, Robert M.: Determination of susponsoids by alternating-current precipitators. Jour. Ind. Hyg., vol. VII, no. G, June 1925. 1 (3) Hillebrand, W. F.: The analysis of Bilicato and carbonate rocks. Bull. 422, United States Geological Survey, Washington, D. C. (4) Cooke, W. E.: Pulmonary asbestosis. Brit. Mod. Jour., Deo. 3, 1927. (5) Green, H.: A photomicrograph! method for the determination of particle I size of paint and rubber pigments. Jour. Franklin Institute, 1921, pp. 192, 637. (6) Whipple, G. C.: Vital statistics. John Wiley and Sons, New York, 1025, p. 451. (7) Russel, A. E., Britten, R. H., Thompson, L. R., and Bloomfield, J. J.: The health of workers in dusty trades. II. Exposure to siliceous dust (granite -,j industry). Pub. Health Bull. No. 187. 1929. Jj ENDEMIC TYPHUS IN ALABAMA1 ! > By J. N. Baker, M. D., James G. McAlpine, Ph. D., and D. G. Gilo, M. D.t ' D. P. H., Alabama Stale Department of Health, Montgomery, Ala. ; I. INTRODUCTION In a preliminary report made in June of this year before tho Con ference of State and Provincial Health Authorities, held in Wash ington, the authors discussed tho epidemiological aspects of endemic typhus as it occurs in southern United States. In that report it was noted that there had been a rapid increase in this disease in certain Southern States, as is shown in table 1, That other countries havo experienced a similar rise in incidence is evidenced by the figures in table 2. ' The distinction between epidemic typhus and the endemic typhus of this country was first recognized in 1898 by Brill. He (1) found in the United States a type of fever which, resembling typhoid, gave a negative Widal reaction. In further studies he (2, 3) demonstrated ; its similarity to typhus, but showed that it was milder in character j and less contagious, only one cusc as a rule being found in a household. I Also he reported that it was most prevalent during the fall of the year instead of late winter or spring. In 1912 Anderson and Goldberger I i (4) proved that Brill's disease was immunologically identical with M`eRexaidcabenforetytbpehluabso,raotorry tsaecbtiaonrdofiltlhoe. AmeNricaatnuPruablllicyHtehailtsh lAesdsoctioatiotnh, ePabsaedleineaf, tChaalif.t, | iBtepwi. a3,s193lo4.uso borne. . 1 Table 1.--Typhus fever incidence in State 1929 Florida... Oftorpla... Alabama. Louisiana Texas--.. 4V'. (If. > 6 months only, to July L Table 2.--Incidence of typh Country Union of South Africa. Mexico ................... United States-------Poland......----......... Rumania-................... i From the Epidemiological Report, Health Section Deaths. For 6 months. Nevertheless, Maxcy (5) (1926) study of Brill's disease, or endemic its noncontagious character and its that tho louse was the vector. Sin< of cases appeared among persons ha to believe that rats and mice migh disease was carried to man by fleas, emphasized the fact that Brill's di. lower strata of society and bears n> step was taken when Dyer, Rumrc able to recover the virus of Brill's been found in typhus foci. Rumreich (7) (1933) has pointed in spite of Maxcy's fundamental w the probable vector of endemic t and arachnids were suspected by vectors were the tropical rat mite, < the body louse, the head louse, the and the tick. It is now obvious tli the fact that two distinct clinical < for this reason Moxcy's observations The work of Rumreich, Dyer, and B that there are in eastern and sout which are related both etiologicaUv is endemic typhus, which is transm other is Rocky Mountain spotted fe