Document Rq0aYaoBKg1pDBb5bYLQOGGv

Memorandum Bill/Fred Subject:Characterization of Automobile Brake Drum Duat ref: Conversation with A.E. Anderson, Scientific Lab, 5/30/78 Samples emitting unaltered chrysotile fibers can result from the following atypical brake usage: New Lining- some direct fiber emissions. Infrequent Brake Usage- resulting in a layer of rust bonded to the fibers. (Fibers can migrate to the surface under wet conditions and bond with rust. Speeds of 15-20 mph. with resulting temperatures are necessary to change the morphology of chrysotile to forsterite.) Abusive Conditions- e.g. driving with the parking brake, weakens the bonding of the fibers to the binder. Unfortunately, studies documenting unaltered fibers do not elaborate on the methods employed for the selection of samples. Results are readily published in the media and the impact occurs nevertheless. Signed Carolyn B. Zelek 0'0n Aanm H\ 7f C0 Oepl. or Location Oats . May 31, 1978 002285 PRODUCED BY FORD