Document NEX6d4KnNZ4GdbOe6jDq7Yo6g

) -' On the Effects of Exposure to the Dust of Eagle-Picher Insulating Material l by Robert A. Kehoe, M.D. and Willard ?. Machle, M.D. The actual methods employed in insulating homes with the type of rock-wool manufactured by the Eagle-Picher Lead Company were observed by visiting several sites at which this work was In progress. Thus the varying dust exposure associated with different operations and the precautions taken against such exposure were seen. The magnitude of the exposure to dusts in the various operations of a job in Cincinnati was determined by collecting samples of air in -;i the immediate vicinity of workmen, under varying conditions, and '4 estimating the quantity of suspended dust. The lead content of a sample of the insulating material was determined hy speotrographic analysis in order to make some estimate of the significance of the lead exposure of the workmen. In order to observe the effects of human exposure to the dusts of the insulating material, a group of men were selected for examination and study from a large group Engaged in insulating buildings. 4 K t 0008284 grouped in working crews in various parts of the country. From the available Information* as shown in Table 1, it was apparent that the group in East Orange, New Jersey^had been employed longest, while the largest group in any one location^and^therefore^ the one most read: iy accessible, was situated at White Plains, Connecticut. These two groups combined could be expected to provide variability of exposure including the greatest which had occurred, and since none of those who had been in these groups had discontinued the work, there had been no factor of selective.elimination. The Albany crew happened to be employed temporarily in White Plains at the time of the examination of the. White Plains group. Their inclusion brought the total number of men examined up to twenty-, . seven. Dust samples were collected in the .attic of a house in process of being insulated, in onrmontileH b oth hand-packing and blowing.' Samples wdre also collected at the air pump used to blow the insulation. The modified Greenburg-Smith impinger was employed with the standard hand-driven suction apparatus. The technique of collection, handling and counting was similar to that described by Bloomfield and 0)^ PaUBVAl 1ft III, TI.'.^C5ma%l ~ -3- V. The complete history of all previous and present employ ment/ and of previous illness was recorded for each man, together with his age, his family history, the general state of his health, and the presence or absence of symptoms of illness or organic disease. Special attention wa3 given to the duration of the present employment^ and the nature of the day's work, with reference to exposure to dusts of insulating material, A complete physical examination was given each man, including tests of the special senses and of muscular power, analysis of the urine for its reaction and for albumin and sugar, and a microscopic study of the blood. That is to 3ay, a thorough search was made for any and all physical Ailments or abnormalities. These observations were recorded on the foxms reproduced in Figures 1 and 2. A sample of blood and two samples of urine were obtained from each man, in chemically clean containers prepared in the laboratory. These were returned to the laboratory for analysis. The "blood and one of the urine samples were examined for lead by a sensitive and accurate , * r-Z. _ ^ TST CrUu_, spectrographlc method which has been described elsewhere CS)J. toe--of-- -istxa- urine sample^ was examined for arsenic by the Gutzeit method. The chest of each man was further examined by means of stereoscopic X-ray photographs taken and interpreted by an experienced Ht 0008286 h radiologist. Another competent radiologist studied all the plates and independently gave his opinion as to their significance. Results and Discussion The results obtained in the dust counts are shown in Table 2. Considering the physical character of the dust particles most of -which hair-llke and therefore would tend to be entrapped in the upper respiratory tract somewhat more readily than natural rock dusts, it is probably that the effects of exposure would be less severe than those produced by similar material of more common structure. In view of the chemical composition of the material one must consider the effects of silica and of certain heavy metals. It Is generally believed that the characteristic lesions of silicosis develop A'-T 0008287 either very slowly or not at all when there are fewer than 5f>00,000 particles of pure silica per cu. ft. a3 determined by a light field method of counting comparable to that employed here^),It would seem, therefore, that the develop ment of silicosis need not be expected in relation to the hand-packing operations, regardless of the form in which the silica may appear In the rock-wool. The hazard of the blowing operation, on the other hand, would depend in part upon the degree of protection provided by the use of masks, and in part upon the proportion of toxic 3ilica In the material. One is 5- justified in the feeling that silicosis might well develop among men employed in blowing operations unless due precautions were taken. The danger of heavy metal poisoning would be great at metals in a soluble stats In the material. Even relatively insoluble compounds of lead, for example, would be potentially dangerous. Here, however, we are dealing in some measure with hypothetical matters, such as the proportion cf material actually inhaled as compared with that swallowed, #ifits solubility and absorbability in the /\ lungs and in the alimentary tract. It seemed best to deal .in-fee these matters practically through the 3tudy of the exposed men rather than by methods based on hypotheses content of two samples of the rock-wool^"^ A sample of material such as is put through the blower showed a lead content of 1.12%, while a sample of that packed by hand was 0.96% lead. Arsenic determinations were not made because of technical difficulties due to the nature of the material. (The exact KF 0008288 . -I irxAd a.4 J-ll.L 1. was considered first as a unit. In no case was there clinical evidence of any occupational illness.or: disease. No man was ill or complaining vaguely of generally poor health. No man had lo3t weight, appetite or strength, nor was there any combination of symptoms or physical signs suggestive of silicosis, or of lead or arsenic poisoning. The only common abnormalities involved the teeth and gums and the upper respiratory tract. Several men had common colds in various stages, and most of them showed some degree of redness and irritation of the mucous membranes of the nose and throat. Only a few had good teeth and clean healthy gums. However, despite, the frequency of dental caries and spongy, congestive^gingivitis, no lead line was observed. (The occurrence of gingivitis and dental caries is so common among working men in general as to have no specific significance.) In the absence of individual cases of occupational illness among the men, further study was made of the group as a whole in search of less definite deviations from the normal which might indicate the existence of some common factor or factors of an insurious type, idle more significant results of such study are set down in tabular form. Table 3 gives the age distribution of the group, and shows that the men under study represent a rather wide range with respect to their age. In tables ij. and 5* the variation in systolic and diastolic blood pressure of the group is shown. ^Tho circula tory system shows evidence of Impairment or abnormal function in most oases of chronic or sub-acute Intoxication, and for that reason any unusual trends in blood pressure are of Importance in group studies of toxic agents^*) Of K 0008289 -7- Cflpi .' the five instances of significantly high systolic blood pressure, fourv J%- were-in persons over forty years of age. The one rather low figure (100) ifftl occurred in an otherwise apparently strong and healthy man. The one definitely abnormal diastolic pressure (105) was found in a man of I4J4.. The occurrence of high blood pressure among persons in the middle and later decades in all walks of life is too common to require further comment. Suffice it to say that the data on these men are not unusual for groups of correspording age in any occupation. Table 6 groups the data on the leucocyfce3^of the blood.. There are no abnormally low results. Six results showing 10,000 leucocytes or more per cubic millimeter of blood were found in persons who had evidences of active or subsiding upper respiratory infections' without disability, or other evidence of infection in the fora of suppurative gingivitis. Tables 7* 8, and 9> give the results of the study of the erythrocytes (red blood corpuscles) of the blood.' Inasmuch as lead absorption tends to cause an increase in the number of "stippled" erythrocytes, and a JT\ 06ft gQ 0 0 later decrease in the total number of erythrocytes, together with a drop in the hemoglobin of the blood, these observations have a direct bearing on the questions of lead absorption in these men. The one low erythrocyte count of 3*^4-00,000, was not accompanied by other evidences of abnormal^ ....? X.T. * .'1 -5 ~ -8- v'|K| The result is not of physiological significance, therefore. All the n^emoglobin determinations^gave results within the normal ranged sJnn-meni^-ggg^^ The study of the stippling of the erythrocytes, likewise .-folded normal results. Observations among large numbers of apparently :o\rnal persons outside the lead trades, made by the methods used in this rtudy, have been reported elsewhere and provide a basis for the '.nterprenation of these findings. The one result of IpO stippled erythrocytes occur ..2? 50 microscopic fields is unusual, but such values in entirely normal and '':.eo.lthy persons* All the other results are well within the customary normal limits. The analytical results obtained on the blood and urine are recorded in Tables 10, 11 and 12. The quantities of lead found in the blood of these men cover a range of variability such a3 tjjgpeal been reported previously in a group of normal healthy students (J) There is no abnormal result in the entire group. The analyses of the urine for lead also yielded results within the normal range as previously determined for large groups of normal persons / )(&!) It is quite certain, therefore, that the inhalation of the dust, of ;he mineral-wool has not resulted in an appreciable lead absorption on the ;art of these men. The arsenic determinations on the urine are subject to similar interpretation. The range of normal values for urinary arsenic is if 2ot as well established as in the case of lead, but the mean excretion of a KF 0008291 -9- litalted.yjrumber of normal per sons/whom we have studied corresponds to that ~Tt* alp obtained in this group of men. relatively high results (i.e. 0.06 mgs. of As203 or more per liter of urine) show no correlation with the higher lead findings, or with the duration or apparent severity of.. the occupational exposure. They may be regarded as random results unrelated to the occupation. The dxamination of the X-ray films by the three radiologists resulted in the general agreement that there were no demonstrable pathologic processes or deposits which could certainly be attributed to occupational exposure to dusts. In several cases there was a distribution of fibrous changes suggestive of incipient silicosis but of such minor character as not to be certainly differentiated from the secondary effects of chronic or subacute upper respiratory infection. One of the radiologic consultants expressed their joint opinion, that the "lesions are more:numerous in this group cf men than one ordinarily sees in a similar number of adult chest films. However, being a small group who have none - - - - to speak of, 02 CT5 one must wonder whether or not the findings^ of significance. I do not see how one can be sure - - - until a considerable time interval has elapsed and another series of films Unmade on the same group of men, - - - -- I concur ' in the conclusion that nothing has been found which can be a*Wwswkwd to the 28000 3 X industrial factors involved." Summary 1. Tile methods used in insulating buildings with Eagle-Picher rock-wool mis1 S.Uinvolve eonsiderable exposure to dusts rising from the material. The hand packing operation was seen to result in suspending less than 500*000 A operating pump, the particles numbered approximately 750/000 per cubic foot in the blowing operation the dust exposure was as'high as 8,000,000 particles per cubic foot. 2. The nature of the material is such as to suggest the possibility of a silicosis hazard. is of doubtful significance, theoretically. The arsenic content was not de termined. j 5. The study of 27 men of whom a number have had more than four years of exposure to dusts in handling the Insulating material, failed to show any clinical evidence of occupational disease or illness. Ip. Study of the lead and arsenic excretion of these men disclosed no evidence of absorption of lead or arsenic in quantities above that which has been shown to occur among normal persons without occupational exposure, 5. Radiographic chest examinations showed no certain evidence of occupatioj pulmonary disease such as occurs in severe exposure to silica. There ivas suggestive evidence of the development of pulmonary changes, but the evidence tf. 000823.) was not sufficiently convincing to justify a diagnosis of early silicosis in any case* References. }' */f * St JJj XL Vm> , 3-/7 , (/13$) r > /4*M LA > ^* 0 'y A . .'uttf v a c,, < * J h, * _> NA ^ *-v;i p \\ j J. ~` " /"I| O fVv^ /1. ^Si* . vJ . 'S V . / >' ^ f 7 j , 7 ^"*- $A>x f/, - , ' /- ' r'j / \' r, S -t'' * *7f ^ *-& ^ l ^ A // yfif %J#e*r' ^ ^ v d&f'yl 1 Jh*u$ &&*(*<j c^^vv^iXcM,. 4^ l\plto2vi*r'rj Xj J)^ jv AlhOj. f * 9Oj (/? 3 h) t\jjL^ 'j / Aa ^mv v ***^ . T^te JIa mm^ ,*f) /' ;< ' V ' \vjtevvA*J^ u-fr^o\|v,iw^ tfsoii j) *><xr% 2 ; / {(\ Ax^\' * iC /vlt* J ^A Ain^ Jj *j k , ^^iAJtSCeH m3 4;Mj i Sf-* o; , ij4,x* <r 5 /S~ : &73/(/fJB) / t; 0008294