Document VJaQOqrn8gXExwbx9Rn7Qn0k8

Inter Office Communication SCIENTIFIC RESEARCH STAFF Detiemberl5,^972',> TO: cc: Hir.iliTlH'll'fffiif 1 SUBJECT: Carcinogenic Effects of Asbestos-WSU Animal Experiments As a follow-up to our previous contact (see attachment) we met vith Dr. Andrew Reeves and his associates at the Wayne State School of Medicine on November 17 Dr. Reeves is now completing work on a contract with the Public Health Service in which s development might well occur at some fraction of the animal's normal life span., rather than at a fixed absolute t'iiite^ Thus, with suitable laboratoryanimals, the dose-time-cancer occurrence relationships for airborne asbestos exposure might be established within a few years. A logical extension of his work is being proposed by Dr. Reeves for a new PHS contract, to be submitted in January 1973 and initiated the following summer. In this study, hgrplans^j^,^Bub-ject"MTTL'abora^o'i^T ter^a^IMt^%ear'^ebgis. Fls^planned" approarhwas to heat chrysotl 1<* ashestos tol5do0F7subject this material to mechanical action, and blow the ensuing airborne material into his test chambers. We suggested that this approach probably would not approximate brake asbestos effluents, After describing what we know of brake lining interfacial phenomena and of the magnitude of asbestos fiber content from brakes in normal service, we suggested three possible alternative approaches. 009566 produced by ford 8000 1178 m fas? SCF-FORD-0949 J. E. Mayer, Jr. J. V. Petrocelli -2 - ,December 5 1972 The first Is to collect brake drum debrisand use this material to simulate the air Jja an automotive brake relining shop. The second is to collect the grinder dust in a brake lining finishing shop to simulate the air in a brake lining manufacturing area. While these samples maybe appropriate to simulate the environmental air for a small group of workers, they would not be expected to simulate the debris from automotive brake usage. Our third suggestion was to generate brake lining wear debris at the WSU laboratory for direct introduction into the animal chambers. The last approach would appear to be preferred, since we all are exposed to brake lining wear debris, yet little is known of its carcinogenic properties. We do know, from our own studies, that much less than 1$ of the asbestos content of the lining is emitted to the atmosphere. Dr. Irving Selikoff, the noted expert on asbestos epidemiology from Mt. Sinai School of Medicine, has stated that he doubts that brake usage contributes significantly to asbestos air pollution. However, a good laboratory test to establish the dose-time-occurrence relationship for brake lining wear debris would appear to be of importance to us all, and particularly to Ford Motor Company as a major purchaser of resin/asbestos friction materials. A preliminary calculation indicates that airborne asbestos concen trations more than a thousand times the typical level (l-lO ng/m?) found in U.S. cities could be generated with a 3 horsepower device which uses standard brake parts. This power level would confine bulk brake temperatures, and thus lining friction and wear behavior, to the normal usage range. It appears prudent that we volunteer our services to aid Dr. Reeves and his associates in recommending this approach of brake lining wear debris generation for his new PHS contract proposal. Our involvement need be as little as a man-week's work, with assistance on test fixture design and brake parts procurement to assure that representative brake debris is generated. Our involvement could logically extend to the design of the brake device and even its construction. We would appreciate your advice in this matter. As of now, we have made no conmitments with Dr. Reeves, but have expressed an interest in his program. ... `' ' nrm Attachment A. E. Anderson Mechanical Research Department R. L. Gealer Chemical Engineering De; 009567 8000 1179 PRODUCED BY FORD