Dr. Kenneth W. Smith to General Motors and Firestone on Asbestos Fiber (1959)

Two one-page letters of December 1959 from Dr. Kenneth W. Smith, Johns-Manville's medical director, answering requests for information about J-M asbestos fiber from the Allison Division of General Motors Corporation in Indianapolis and from the purchasing agent of The Firestone Tire & Rubber Company in Akron, Ohio. Both letters say it is a recognized fact that long, continued inhalation of enough asbestos fiber may cause some lung changes, but that J-M had developed no new cases of asbestosis at its mines and mills for many years. Smith advised proper material handling and local exhaust ventilation, with respirators approved by the U.S. Bureau of Mines where dust could not be controlled; the General Motors letter also cites a limit of 5 million particles per cubic foot.

What it shows

This was J-M's standard answer to customers that year: the same points appear in Smith's letters to the Pine Bluff Arsenal and the Michigan Department of Health. Blind copies went to H. M. Ball and to D. L. Munroe of the Asbestos Fibre Division at Asbestos, Quebec.

In Johns-Manville's chronology

Johns-Manville's own chronology of what the company knew describes this document as follows:

Dr. K.W. Smith response (12/21/59) to General Motors' and Firestone Tire & Rubber Company's request for information regarding asbestos fiber. Dr. Smith states that it is a "recognized fact" that long and continued inhalation of sufficient quantities of asbestos fiber may cause "some" pulmonary changes, but there have been no new cases of asbestosis among J-M mine and mill workers for many years. Dr. Smith recommends proper handling methods and local ventilation to eliminate any hazard which might exist. Workers should wear respirators if these suggestions cannot be followed.