H. M. Jackson to C. B. Burnett on Dr. Bristol's X-Ray Readings at Six Plants (1969)

A two-page memo of October 10, 1969, from H. M. Jackson, manager of J-M's industrial health program, to C. B. Burnett, Johns-Manville's president, comparing the plant doctors' readings of workers' chest X-rays with those of Dr. L. J. Bristol of the Saranac Institute at six plants: Manville, Pittsburg, Marrero, Long Beach, Nashua and Waukegan. Taking Bristol's readings as the standard, Jackson found that, except at Manville ("comparable") and Long Beach ("over-reading"), "the plant physicians at these locations are under-reading the X-ray indications of pneumoconioses." A table set out, for each plant, the number of cases and a "potential" workers' compensation total-disability liability, which Jackson called a maximum figure based on "the unlikely assumption that all cases will proceed to total disability": more than $20 million at Manville alone.

What it shows

Jackson drew a plain conclusion: the data "indicate, however, that past exposure levels, at least, have caused a substantial frequency of disease, and therefore environmental control to the new threshold limits must be obtained rapidly if we are to minimize future disease production and the attendant potential liability." He also pointed to a two-year Tulane University study at Marrero by Dr. Hans Weill. He reported that he and Dr. George W. Wright, a physician advising J-M, had not yet settled on a recommendation for the plant doctors' under-reading, and mentioned better training for plant physicians or having one specialist such as Bristol read all X-rays. Bristol's readings were also sent back to the plants for follow-up (Jackson's November 1969 instructions to Marrero). The Bristol program grew out of his earlier X-ray survey at the Jeffrey mine (Dr. Smith to Dr. Bristol, 1966).

In Johns-Manville's chronology

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

Memorandum from Jackson to Burnett, 10/10/69. States that using Dr. Bristol's readings as the criteria, it is apparent that with the exception of Manville and Long Beach the plant physicians are under-reading the x-ray indications of pneumoconiosis. Jackson expresses concern but makes no specific recommendation.

Editor's note: J-M's description says Jackson made no specific recommendation. The memo says a recommendation was still being prepared, but it does urge that dust be brought under the new threshold limits quickly.