Hardy and Egilman [1991] seem to be accusing Gardner and Vorwald of suppressing the results of animal studies carried out in the 1940s and 1950s at Saranac Laboratory in order to protect their industry sponsors. Over the past few years I have accumulated copies of letters and unpublished reports of the type referenced by Hardy and Egilman. Assuming these to be valid, it seems to me they suggest other and more probable reasons why the Gardner-Vorwald animal data were never published.
On February 24, 1943, Gardner submitted an outline for a proposed monograph on asbestosis to the Johns Manville Corporation. In this he reported 8 malignant tumors of the lung among 11 mice inhaling long asbestos fibers for 15-24 months. Among 22 mice inhaling short asbestos fibers for less than 12 months, 3 developed lung tumors. Gardner compared this with his experience with mice in other dust experiments. Among these animals there were 51 mice exposed for 10 to 12 months and here the incidence of lung tumors was 1.9%, while for 143 animals exposed for 23-31 months the incidence of lung tumor was 18.8%. He thought the incidence in mice inhaling long fibers was excessive but pointed out that the observations made were only suggestive evidence of a cancer stimulating action by asbestos dust. He said that the strain of mice was not the same in the asbestos experiments as in many of the others cited and that, apparently, the former were unusually susceptible. Moreover, not enough animals survived in the dust for longer than the 15 months apparently necessary to induce many tumors and there were no unexposed controls of same strain and age and no similar controls exposed to other dust. He stated in his covering letter that he believed his data on lung cancer ". . . would better be omitted from the present report," and that he would obtain support from the cancer research group for a new study. Subsequently, on March 15, 1943, Dr. Gardner applied to the National Cancer Institute for funding and reported his preliminary findings. In this letter he stated: "Obviously under such conditions, the results with asbestos mean nothing but in view of considerations I have cited, I believe they should be checked."
This grant request was apparently turned down.