Dr. Kenneth W. Smith to F. M. Stumpf of Columbia Acoustics and Fireproofing on Asbestos Hazards (1957)

A one-page letter of September 30, 1957, from Dr. Kenneth W. Smith, J-M's medical director, to F. M. Stumpf, vice president for research at Columbia Acoustics and Fireproofing Company in Stanhope, New Jersey, who had asked about health hazards in handling asbestos. Smith writes that "continued inhalation of asbestos fiber in sufficient quantities over a long enough period of time may cause some pulmonary changes," but that in J-M's mines and mills, with about two thousand workers, "we have developed no new cases of asbestosis for many years." He recommends proper material handling, local ventilation and, where those fail, respirators approved by the U.S. Bureau of Mines.

What it shows

Smith adds that where asbestos is mixed with a toxic dust such as silica, more precautions are needed, while with an "inert" dust such as mineral wool "the potential exposure is much less." His statement about no new cases concerns the mines and mills. The same month, a review of X-rays at J-M's Manville, New Jersey, plant found eight cases of mixed pneumoconiosis among 109 Transite pipe workers (Sheckler's report).

In Johns-Manville's chronology

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

Letter from Kenneth Smith to F.M. Stumpf, Columbia Acoustics and Fire-proofing Company, 9/30/57, concerning potential health hazards associated with the handling of asbestos. Smith notes the general risk but represents that among 2,000 J-M workers handling in excess of 500,000 tons of asbestos annually: "We have developed no new cases of asbestosis for many years." Smith recommends ventilation and respirators, and points out that: "In certain manufacturing operations asbestos is mixed with other dusts. Should these additional dusts be potentially toxic such as silica additional precautions should be taken. On the other hand if the other dust is inert such as mineral wool, the potential exposure is much less."