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FILE NAME Brakes BRK DATE 1968 DOC BRK030 DOCUMENT DESCRIPTION Unpublished Report for Manville - The Pulmonary Response to Brake Dust 432 1 7 DOCUMENT NUMBER INDEXED BY DOCUMENT TITLE Gross Gross Paul EDITED BY DOCUMENT NO = PAGE OF 3071 LOCATION a ES KEY CODE 7 72 72 913 913 43 40 KEY WORD OR CHARACTERISTIC The Pulmonary Response to Brake Dust Preliminary Preliminary A Preliminary Investigation Investigation Investigation Ind Hy Foundation - Report for M UNPUBLISHED July 1968 | e SCOPE NOTES thot thot to circulate ! can oa Z im usatifice usatificeusatifice Ten penev., usatifice puly FE ; - 80 SumSummmaarryy pulmonary BB rr aa ke ke dustdust has ee vvookkeed d a pulmonary response iin n rats and which which that this this suggest that this dust is biologically inert Brake dust harsters is cacpaapabbllee of prproodduucicnig ng ffeerrrurgiunoguis nous bodibodies es iin n the lungs of hamsters tthhat at are in- distinguishable from asbestos bodies E83289 KEYDEX 1962- MCBEE FORM 1130 INDEX / TRACING CARD ee eeere ESTABLISHED 1935 J 71 412 621-1100 1 a INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC 4400 FIFTH AVENUE PITTSBURGH PA 15213 410 STE INFORMATION 2M8 INFORMATION W. Report on SHERBROOKE 1130 MONTREAL THE PULMONARY RESPONSE / BRAKE DUST A PRELIMINARY INVESTIGATION for MANVILLE CORPORATION by Paul Gross M.D. Director of Research Laboratory Industrial Hygiene Foundation Robert T. P. deTreville deTreville M. D. President AN ASSOCIATION OF INDUSTRIES FOR THE ADVANCEMENT OF HEALTHFUL WORKING CONDITIONS 2 * IND^ STRIALHYGIENE FOUNDATION OF AMERICA 3 ry Three of the hamsters were killed 7 1/2 months after the injection and lung washings were obtained from these animals using a modified LaBelle and Brieger technique The sediments from these washings were smeared upon slides which were allowed to dry and were examined microscopically unstained All remaining hamsters and rats were killed 12 months after the in- tratracheal dosage All lungs were distended with formalin under a pressure of 10 to 12 cm of water Paraffin sections were cut and stained with hematoxylin and eosin Pertinent fields on these slides were photographed after which the slides were decolorized and impregnated with silver using Gordon and Sweets technique same The fields were then rephotographed The coverslips were then removed and the slides subjected to microincineration for one hour at 600 C. After treatment with concentrated hydrochloric acid and washing with water the same fields were photographed for a third time but now under field illumination By printing through a composite negative made by superimposing the field negative upon either light field negative a picture is obtained that relates the mineral dust to the tissues and cells N INDUSTRIAL HYGIENE FOUNDATION OF AMERICA 5 Longer Reaction A. Seven and half months hamsters The lungs of hamsters killed at this time are nearly normal except for widely scattered foci in which a few alveoli contain clusters of macrophages are and the lining cells of their septa excessively numerous and swollen An occasional giant cell is also found in the air spaces Smears of the sediment from the lung washings show scattered asbestos bodies many of which are segmented Fig 3 B. Twelve months rats and hamsters The only significant lesions found in the lungs of these animals are accumulations of filled macrophages within widely scattered clusters of alveoli associated with slightly increased arborescence of alveolar argyrophilic fibers Figs 4-6 In some instances the affected alveoli can be identified as ones that were evaginating off alveolar ducts or respiratory bronchioles No collagenization of alveolar walls or obliteration of alveolar lumens is demon- strable Also noteworthy is the fact that in rats in spite of a fold greater dosage the amount of alveolar involvement at one year is not greater than that seen at four days with only one dose of 3.5 3.5 mg of dust A similar discrepancy is found in the lungs of hamsters also show a degree of pulmonary involve- ment at one year with a total dosage of 10.5 mg not greater than that of ham- sters four days after a single injection of 3.5 mg INDUSTRIAL HYGIENE FOUNDATION OF AMERICA 7 dust could be ascribed to inadequate dosage This may be true However from a practical point of view it is not likely that a city dweller is apt to inhale more than an extremely small dose during a hour exposure and as seen in these animals there is no tendency for the lungs to accumulate 14 compact and sequester the dust as is seen with certain other dusts Con- sequently removal of the inhaled brake dust from the lungs may be expected to be good Nevertheless it is advisable to repeat this study with a larger number of animals using also larger dosages and allowing the animals to live out their lives Conclusions Brake dust has evoked a pulmonary response in rats and hamsters which suggests that this dust is biologically inert Brake dust is capable of producing ferruginous bodies in the lungs of hamsters that are indistinguishable from asbestos bodies INDUSTRIAL HYGIENE FOUNDATION OF AMERICA References continued 9. Gross .; Treville R. T. .; Cralley L. .; Davis J. M. .: Pulmonary Ferruginous Bodies Development in Response to Filamentous Dusts and a Method of Isolation and Concentration Arch Path 539-546 539-546 May 1968 10. Gross P. al The Effect of a Synthetic Ceramic Fiber Dust upon the Lungs of Rats Arch Indust Health 161-166 February 1956 11. Gardner L. .: Studies on the Relation of Mineral Dusts to Tuberculosis Part II The Relatively Early Lesions in Experimental Pneumoconiosis Produced by Carborundum Inhalation and Their Influence on Tuberculosis Am Rev. Tuberc 344 1923 12. Gross .; Westrick M. .; McNerney J. .: Experimental Tuberculo- pneumoconiosis Arch Indust Health 320-334 March 1959 13. Gross P. and Nau C. .: Lignite and the Derived Activated Carbon The Pulmonary Response to their Dusts Arch Environ Health 450-460 March 1967 14. Brieger H. and Gross .: On the Theory of Silicosis III Stishovite Arch Environ Health 751-756 December 1967 -t @ew WF b he. Bret 7 wR: f > wo we Fig 3 Region of an alveolar duct one year after intratracheal injections of brake dust The tissue reaction at this time is not significantly different from that of Fig 1 and still consists only of clustered macrophages Hematoxylin and eosin ^ 150 Fig 4 The same field as in Fig 3 but after silver impregnation showing minimal arborescence of mural argyrophilic fibers Gordon and Sweets ^ 150 NORE i ae " Sn Es Me%ndoVt ee fey bf of reed inal a: Pe if ae -* i ee me , 1 os aN ae a ~ | eo _s { +; x Te Me | ae a ty an iad ore oeD a mmf af eh ? . . eo a Perens 4 * e es e@ . 3 wow wl, i } a a ees tafi Nee . a - < . a Composite picture of the same field as in Fig 3 showing that the macrophages still contain abundant mineral dust x 150 Fig 6 Smear of lung washings from a hamster injected intratracheally with brake dust seven months previously showing a typical segmented asbestos body Eosin only x1150