John F. McMahon and Vandiver Brown on May Mayers's Article Linking Asbestosis and Lung Cancer (1950)

Two letters. On May 17, 1950, John F. McMahon, managing director of the Industrial Hygiene Foundation of America in Pittsburgh, sent Vandiver Brown, Johns-Manville's secretary and attorney, an excerpt from an article on occupational cancer by Dr. May R. Mayers of the New York State Department of Labor (Compensation Medicine, March 1950). It began, "The relation of asbestos to lung cancer has long been suspected," and cited the British Chief Inspector of Factories' report for 1947, in which cancer of the lungs or pleura was found in 13.2% of asbestosis deaths. McMahon asked whether any such cases had been reported in the United States or Canada.

What it shows

Brown answered on May 19 that J-M knew of the British report and of several recent statements listing asbestos dust as a suspected carcinogen. "Our own experience lends no confirmation to this theory, although we are naturally very much concerned and are contemplating animal experimentation for the purpose of testing the theory." Consultations with Drs. Lanza and Vorwald, he wrote, had produced opinions "which can best be characterized as Scotch verdicts, that is 'not proven'." The British report is the Chief Inspector's report for 1947.

In Johns-Manville's chronology

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

An excerpt from an article by Dr. M.R. Meyers from the 3/50 issue of Compensation Medicine notes that development of cancer of the lung in workers studied in the 1947 report of the Chief Inspector of Factories in England is believed to be "more directly related to asbestosis, the disease, than to the inhalation of asbestos dust per se. The article points out that the histologic character of the tumors and their histogenic derivation is interpreted to indicate the presence of an exogenous carcinogenic agent as the etiological factor. J. McMahon (IHF) sends a copy of the excerpt to V. Brown. In a letter dated 5/19/50, Brown responds that he is aware of the existence of the report. He states "our own experience lends no confirmation to this theory, although we are naturally very much concerned and are contemplating animal experiments for the purpose of testing of the theory." Brown states that "[o]ur consultations with Drs. Lanza and Vorwald have elicited opinions which can best be characterized as Scotch verdicts, that is 'not proven'."

Editor's note: J-M's description names the article's author as Dr. M. R. Meyers. The letters give her as Dr. May R. Mayers of the New York State Department of Labor.