Lompoc Plant List of Improvements to Reduce Dust, 1930 to 1944 (1945)

A three-page list dated March 12, 1945, from Johns-Manville's diatomaceous earth operation at Lompoc, California, headed "Improvements in Processing Units and Facilities to Reduce Dust Conditions." Year by year from 1930 through 1944 it records new cyclones, dust towers, baghouses, exhaust systems, a vacuum cleaner for walls and floors, a dust-tight dump truck body, paper bags to replace leakier packing, and concrete floors "for better housekeeping." It closes by saying that "Employees are required to wear respirators where the need is indicated," and lists the Bureau of Mines-approved models the plant had bought.

What it shows

The list shows that dust at Lompoc was a recognized problem the company had worked on for fifteen years, with experiments from 1938 on collecting dust that "escaped" and a Cottrell precipitator being installed in 1945. It says the plant bought the respirators "giving the most comfort and satisfaction to the employees"; it says nothing about telling workers what the dust could do to them. Lompoc's diatomaceous earth workers had been X-rayed by Metropolitan Life in 1937 (see the Lanza letter), and Vandiver Brown wanted Gardner's help with the "problem" there in December 1944. See Dust Control.

In Johns-Manville's chronology

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

Improvements in the processing units and facility to reduce dust conditions from the year 1930 through 1944 at Lompoc are listed on a document dated 3/12/45 or 3/13/45. The document indicates that "employees are required to wear respirators where the need is indicated. Improved respirators have been tried out as they have appeared on the market and we have continued to purchase those giving the most comfort and satisfaction to the employees."