Leroy Gardner to Ivan Sabourin on Asbestosis and Tuberculosis (1944)

A four-page letter of February 28, 1944, from Dr. Leroy Gardner, director of the Saranac Laboratory, to Ivan Sabourin in Montreal, with a copy to Vandiver Brown. Sabourin had asked whether asbestosis makes workers more likely to get tuberculosis. Gardner reviews British and American studies and his own film reviews and concludes that "asbestosis does not favor or predispose to tuberculosis," adding that he is "more and more convinced" the high tuberculosis rates in English autopsy statistics have causes other than occupation.

What it shows

To make his point about tuberculosis, Gardner describes 125 X-ray films he had just reviewed for "an asbestos fabricating plant in another state." At the first examination in 1930, about 40% of the group showed "definite X-ray evidence" of asbestosis; among 67 re-examined five years later, while still at work, the share had risen to 62%; and among 57 examined three to four years after that it was "over 80%." He calls these "excessive amounts of severe asbestosis." He also writes that the dust reaction in Quebec "is very much less than it is in the fabricating plants in the United States." The letter records, in passing, a steep rise in asbestosis among workers who stayed on the job at one American plant.

In Johns-Manville's chronology

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

Letter from Leroy Gardner dated 2/28/44 to Ivan Sabourin. This letter responds to a letter from Sabourin asking for comments on the relationship between asbestos exposures or asbestosis and susceptibility to tuberculosis. Gardner summarizes the literature concerning the U.S. experience and reiterates his conclusion that asbestos exposures do not predispose to tuberculosis. He also observes that he is becoming increasingly convinced that the TB rates reported in English autopsy statistics are due to non-occupational causes.