Draft Summary and Chart of Dr. L. J. Bristol's X-Ray Study of J-M Plants (1970)

A four-page draft summary, dated November 25, 1970, of the chest X-ray study Dr. L. J. Bristol of the Trudeau Institute did for Johns-Manville, with a one-page chart dated November 24. The chart lists 25 J-M plants, the number of X-ray sets Bristol read at each (8,860 in all), and how many showed bronchovascular prominence or pneumoconiosis. The highest rates of pneumoconiosis were at Billerica (30.0%), Nashua (11.7%) and Pittsburg (10.5%), followed by Long Beach, Manville and Waukegan at about 8%.

What it shows

The draft is signed H. M. Jackson and is close to word for word the final version of December 11, which concludes that "the health problems are severe in seven plants." It says the study left out the Jeffrey Mine and the Asbestos, Quebec, plant because they were part of a separate study by Dr. J. C. McDonald of McGill University. In numbers, the chart shows 264 X-ray sets read as pneumoconiosis at Manville, 112 at Waukegan and 40 at Marrero, 524 across the company.

In Johns-Manville's chronology

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

Chart dated 11/24/70, summarizing the results of Dr. Bristol's study. Lists names of plants, number of X-ray sets reviewed, number and percentage with bronchovascular prominences, and number and percentage with pneumoconiosis. The plants with the highest incidence of pneumoconiosis are Billerica: 30%. Pittsburg: 10.5%. and Nashua: 11.7%.