Leroy Gardner, Progress Report on Asbestos Experiments (1938)

A four-page progress report of December 9, 1938, by Dr. Leroy U. Gardner of the Saranac Laboratory, written "in reply to your letter of the 6th." After 20 months in dust of 125 to 160 million particles per cubic foot, animals in the original experiment, "undertaken with the grant from the asbestos industry," showed no gross fibrosis, only scattered early fibrous tissue. Gardner concluded that the finely ground fiber had lost much of its "capacity to irritate the lungs" and that the irritation was "more probably of a mechanical nature," and he described a new experiment with long-fibered chrysotile.

What it shows

The report contrasts these results with an earlier experiment in which far lower concentrations, 39.5 to 55.6 million particles per cubic foot, "had already produced gross evidence of fibrosis in the lungs after 15 months exposure." Chrysotile still could not be injected into the veins without killing the animals. The new long-fiber inhalation test used 100 guinea pigs, 20 rats, 20 mice and 6 cats. The report shows the sponsors being told early that grinding the fiber fine had changed the results.

In Johns-Manville's index

Johns-Manville's legal department indexed the Motley 1,000 in 1984. Its index describes this document as follows:

Document entitled "Progress Report on Asbestos Experiments," 12/9/38, authored by Dr. L.U. Gardner. (Duplicate of a portion of Motley Document #810.)

Related documents

• R. E. Cryor of Union Asbestos & Rubber to C. Mosier on Gardner's Asbestos Dust Experiments (1938)

About this copy

This is document 1024 of the Motley 1,000, from the set the Manville Personal Injury Settlement Trust's records facility certified as true copies, pages CRMC-Motley1000-Subj-005276 to CRMC-Motley1000-Subj-005279.