Asbestos and Disease by I.J. Selikoff and D.H.K. Lee - Chapters 2 to 6

Our plain-English summary of Asbestos and Disease by I.J. Selikoff and D.H.K. Lee - Chapters 2 to 6, by I.J. Selikoff, D.H.K. Lee (1978).

The study

• Authors: I.J. Selikoff, D.H.K. Lee
• Published: ASBESTOS AND DISEASE, NEW YORK: ACADEMIC PRESS, PP. 33-141 (1978)
• Type of article: Book excerpt
• Our copy: from Johns-Manville's own medical library.

In plain English

This text is chapters 2 to 6 of the authors' book Asbestos and Disease. The book reviewed existing knowledge rather than reporting a single study. The chapters described the asbestos minerals (chrysotile and the amphiboles crocidolite, amosite, anthophyllite and actinolite-tremolite) and their mining, milling, manufacture and use. They covered fiber identification and counting methods and measured levels in workplaces, neighborhoods, city air, water, food, drugs and consumer products. For example, chrysotile was found in nine of ten brands of taping and spackling compounds. In brake servicing, 56-96% of fibers counted by electron microscopy were too short to be seen by light microscopy. Chapter 6 proposed five criteria for judging causation and described four main disease processes: parenchymal asbestosis, pleural asbestosis, mesothelioma of the pleura or peritoneum, and asbestos-associated carcinoma. The authors concluded that counting only fibers longer than 5 micrometers made levels away from industry look low, while electron microscopy showed asbestos to be virtually ubiquitous in urban air. They reserved judgment on its health significance until reviewing the biomedical evidence. They noted tenfold variation between repeat analyses of dilute or difficult samples.

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: Review monograph (book chapters 2 to 6) summarizing mineralogy, industrial processes, measurement methods, environmental measurements and clinical concepts, drawn from published reviews and studies, including the authors' Mount Sinai group
• Who was studied: No single study population. The chapters reviewed measurements in mines, mills, textile plants, shipyards, insulation and building work, brake servicing, neighborhoods near plants and mines, urban air, water supplies, beverages, drugs and consumer products, mostly in the United States, Canada, Britain, South Africa and Finland
• Exposure: Chrysotile and the amphiboles crocidolite, amosite, anthophyllite and actinolite-tremolite, plus tremolite-contaminated talc. Products and jobs covered included asbestos-cement, vinyl asbestos floor tile, asbestos paper, friction materials, textiles, sprayed and field-fabricated insulation, brake servicing and dry wall finishing
• Main results:
  • In a Mount Sinai study of dry wall construction, chrysotile was found in nine out of ten brands of taping and spackling compounds
  • In brake servicing in New York City, electron microscopy showed that 56-96% of all fibers were shorter than 0.375 micrometers and would not be seen if light microscopy alone were used
  • In a Mount Sinai analysis of 51 common commercial talcs, the talc mineral content averaged 51%, and the asbestos content was reported to range as high as 87%
  • At the Devonport Naval Dockyard in England (reported by Harries), mean fiber concentrations during removal of insulation ranged from 88 to 257 fibers per milliliter counted by light microscopy. During removal of sprayed crocidolite they ranged from 20 to 500 fibers per milliliter
  • Of 49 large- and small-volume parenteral (injectable) drugs examined at Mount Sinai, eight had asbestos concentrations at least ten times the average background. None of the oral drugs showed significantly high concentrations
  • Of six papier-mache products used by children and examined at Mount Sinai, three contained asbestos (chrysotile and tremolite varieties)
  • Fibers in Duluth drinking water closely matched, by electron microscopy, debris from the taconite mill tailings discharge into Lake Superior
  • Chapter 6 distinguished four major disease processes in persons exposed to asbestos: parenchymal asbestosis, pleural asbestosis, mesothelioma of the pleura or peritoneum, and asbestos-associated carcinoma. It also proposed five restated criteria for judging causation
• The authors' conclusion: The authors concluded that when only fibers longer than 5 micrometers are counted, concentrations away from industry appear low or undetectable. When smaller fibers and mass concentrations found by electron microscopy are counted, asbestos up to 10 ng per cubic meter appears virtually ubiquitous in urban air. They stated that judgment on the biomedical significance of these levels should be reserved until the biomedical evidence has been reviewed
• Limitations the authors state:
  • The authors noted that a tenfold variation can be expected in replicate quantitative analysis of dilute or difficult samples
  • The authors stated that hard data on actual air concentrations are scarce, and that averaged summaries may smooth out peaks
  • The authors noted that reservations are needed about grossly averaged data such as the mine and mill figures
  • The authors acknowledged that data from their own Mount Sinai group may receive more attention than others' work

Topics

Medical terms in this study, explained in our Lexicon: Asbestos, Chrysotile, Amphibole Group, Crocidolite, Amosite, Anthophyllite, Actinolite, Tremolite.

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