Dust Control Techniques In The Asbestos Industry

Our plain-English summary of Dust Control Techniques In The Asbestos Industry, by J. Goldfield, F.E. Brandt (1974).

The study

• Authors: J. Goldfield, F.E. Brandt
• Published: American Industrial Hygiene Association Journal 35(12):799-808, December (1974)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 001268. The article is still under copyright, so we describe it here rather than post it.

In plain English

This 1974 article, by two authors from Johns-Manville Products Corporation, was a descriptive engineering paper, not a study of disease. It explained how asbestos dust was controlled in mining, milling and manufacturing, with examples from asbestos mills, asbestos-cement pipe plants and textile operations. The methods included enclosures, exhaust ducts, filters and vacuum cleaning. Its background section summarized earlier research by others. The authors reported on two company pipe plants, in Stockton, California, and Denison, Texas, started in 1957 and 1958. Over sixteen years, doctors reading workers' regular chest x-rays had not detected a single case of lung change consistent with asbestosis or fibrosis. The article gave no worker numbers. An old electrostatic precipitator at the Jeffrey Mills was about 70% efficient, while the fabric filter now in use exceeded 99.99%. Cotton sateen filters were more efficient than synthetic ones. The authors noted that some health effects may take thirty years to develop, so current controls could not yet be fully evaluated. They concluded that the only moral stance was to use the best available controls and keep improving them.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Descriptive engineering paper on dust control methods (not an epidemiological or clinical study)
• Who was studied: No formal study population. The article describes asbestos mills, asbestos-cement (Transite) pipe plants and textile operations, and mentions workers at two Johns-Manville pipe plants: a three-machine plant in Stockton, California (started mid-1957) and a two-machine plant in Denison, Texas (started early 1958). The number of workers is not given.
• Exposure: Asbestos fiber dust in mining, milling and manufacturing. The article discusses chrysotile, crocidolite and amosite, and states that chrysotile made up 95% of the over 800,000 tons of asbestos used yearly in the United States.
• Main results:
  • At the Stockton and Denison pipe plants, sixteen years after start-up, doctors reading workers' regular chest x-rays had not detected any lung change consistent with asbestosis or fibrosis. This was a company observation; no counts were given.
  • A former high-voltage electrostatic precipitator at the old Johns-Manville Jeffrey Mills had poor efficiency, about 70%.
  • The fabric filter now in use at the Jeffrey Mills filters about 5,000,000 cfm with efficiency exceeding 99.99%.
  • Data collected showed that fabric filters of cotton sateen cloth were more efficient than filters of various synthetics.
  • Low-energy scrubbers were more efficient than cyclones but not efficient enough to prevent visible dust discharges.
  • Most dust and low-pressure pneumatic conveying systems function well at duct velocities of 4000 to 4500 feet per minute.
• The authors' conclusion: The authors concluded that the only moral stance was to use the best available control methods and to keep seeking to improve them.
• Limitations the authors state:
  • Because some health effects may take about thirty years to develop, engineering improvements made today cannot be fully evaluated until much later.
  • The amount of exhaust air needed for each dust source can only be judged from experience.
  • The paper gives only selected examples; a full description of dust control in asbestos mining and manufacturing is beyond its scope.

Topics

Medical terms in this study, explained in our Lexicon: Dust Control, Johns-Manville, Asbestos-Cement Pipe, Chest X-Ray, Fibrosis.

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