Saranac Laboratory, Asbestos Pneumoconiosis: Experimental Studies, Report to Johns-Manville (1949)

The Saranac Laboratory's 76-page confidential report of January 31, 1949, "Asbestos Pneumoconiosis: Experimental Studies," submitted to the Johns-Manville Corporation by its director, Dr. Arthur J. Vorwald. It reports the animal experiments begun by Leroy Gardner under the asbestos companies' 1936 agreement (the Saranac agreement): asbestos fibres produced lung fibrosis in guinea pigs, rats, cats and rabbits but not mice or dogs, and long fibres were "essential" while short ones were not. Typical asbestosis was produced in air averaging 138 million particles per cubic foot, of which only 0.6% were fibres longer than 10 microns.

What it shows

The report also finds that inhaled asbestos "did not alter significantly" experimental tuberculosis in guinea pigs. Its section on mice reports no tumors. The September 30, 1948, draft, as Vandiver Brown described it in his memo to the sponsors, had reported pulmonary tumors in 9 of 11 mice exposed for a year to long-fibre dust, and Brown had argued that any reference to "neoplasms" was premature (Brown's March 1949 letter). The report follows Gardner's 1939 interim report. This copy is stamped "United States Gypsum Co. Library."

In Johns-Manville's chronology

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

Report dated 1/31/49 on Saranac animal experiments compiled in "Asbestos Pneumoconiosis". Copies distributed within J-M, and by JM to New Jersey Labor Department.

Editor's note: J-M's description says copies were distributed within J-M and by J-M to the New Jersey Labor Department. Nothing in this file shows that distribution.

Related documents

• Leroy Gardner, Interim Report on Experimental Asbestosis at the Saranac Laboratory (1939)
• Memorandum of Agreement Funding Gardner's Asbestos Experiments at Saranac Laboratory (1936)