The physical and molecular structure of asbestos

Our plain-English summary of The physical and molecular structure of asbestos, by R. Gaze (Annals of the New York Academy of Sciences, 1965).

The study

• Author: R. Gaze
• Journal: Annals of the New York Academy of Sciences
• Published: 1965;132(1):23-30
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy.

Summary of the article

This article, by an author from The Cape Asbestos Company Limited, London, was written as an introduction to a monograph on the biological effects of asbestos. It described the physical and molecular structure of the commercially important asbestos minerals and highlighted features the author considered significant for biological and pathological study. The author defined asbestos as any mineral that breaks down into fibers when crushed or processed. Unlike man-made inorganic fibers, asbestos can go on subdividing into fibers almost to molecular dimensions. Chrysotile (white asbestos) accounted for over 90 per cent of world usage. Crocidolite (blue asbestos), amosite and anthophyllite were described as amphiboles, and tremolite and actinolite were mentioned as of little commercial interest. Tables gave typical chemical analyses and physical properties. Summarizing published electron-optical and structural studies, the author reported that chrysotile fibers are hollow tubes formed from rolled-up sheets, with the finest fibers normally 150 to 400 Å in diameter. The smallest amphibole fibers, usually 800 to 1000 Å, are solid. Fiber lengths ranged from 2 inches or more down to barely more than the diameter, and many fibers in asbestos dust were too small to be resolved by optical microscope. The author stated that this must be taken into account in assessing dust-counting methods. He also described the unpredictable behavior of fibers in air, including agglomeration into balls of fluff and the formation of "parachutes", and suggested research on their electrical and surface properties.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This article, by an author from The Cape Asbestos Company Limited, London, was a short descriptive overview of asbestos minerals. It was written as an introduction to a monograph on the biological effects of asbestos, and it did not study people or animals. The author described chrysotile (white asbestos), said to account for over 90 per cent of world usage, and two amphiboles, crocidolite (blue asbestos) and amosite, and briefly mentioned anthophyllite, tremolite and actinolite. Summarizing earlier research, the author explained that chrysotile fibers are hollow tubes formed from rolled-up sheets, with the finest normally 150 to 400 angstroms across. The smallest amphibole fibers are solid and coarser, usually 800 to 1000 angstroms. The author stressed that many fine fibers in asbestos dust are too small in diameter to be resolved in an optical microscope, which must be taken into account in assessing dust-counting methods. The author also noted that identifying single fibers in pathological work remained a problem. The author described airborne fibers clumping into balls of fluff or splitting into "parachutes", and suggested further research on fiber surface properties.

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: Narrative descriptive overview (not an original study), written as an introduction to a monograph
• Who was studied: No human or animal population. The article described asbestos minerals: chrysotile, crocidolite and amosite in detail, with anthophyllite, tremolite and actinolite mentioned in passing.
• Exposure: No exposure was studied. The article described the mineral types and fiber properties of chrysotile and the amphiboles (crocidolite, amosite, anthophyllite, tremolite, actinolite).
• Main results:
  • Chrysotile was described as accounting for over 90 per cent of world asbestos usage, with the largest deposits in Canada, Russia and Rhodesia.
  • Summarizing earlier research, the author described chrysotile fibers as hollow tubes formed from rolled-up sheets, with the finest fibers normally 150 to 400 angstroms in diameter.
  • The smallest amphibole fibers were described as solid, usually 800 to 1000 angstroms in diameter, and coarser than the finest chrysotile fibers.
  • The author stated that the different amphibole fibers generally cannot be told apart with certainty by electron-optical methods.
  • The author stated that identifying single fibers, or the minute quantities of asbestos often involved in pathological investigation, continued to be a problem.
  • The finest fibers, 100 to 1000 angstroms in diameter, were described as always present and present to a considerable extent in asbestos dust. The author stated that many have diameters too small to be resolved in an optical microscope, and that this must be taken into account in assessing the value of dust-counting methods.
  • The author described airborne fibers as behaving unpredictably: they clump into balls of fluff, and individual fibers split at the ends to form "parachutes" that stay suspended or even rise in air.
• The authors' conclusion: The author considered the behaviour of asbestos fibers in air to be insufficiently understood. The author suggested research on the electrical and other surface properties that cause fine asbestos dust to agglomerate, and presented the summary as highlighting features likely to be significant for asbestos's biological effects.
• Limitations the authors state:
  • The author stated that the chemical analyses given are only a guide to typical composition, because of impurities and ionic replacement.
  • The author stated that the physical properties of fibers may vary significantly from deposit to deposit.
  • The author described the account of the minerals as brief and general.

Topics

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

Related studies

• How are the physical and chemical properties of chrysotile asbestos altered by a 10-year residence in water and up to 5 days in simulated stomach acid? — K. Seshan (1983)
• Mineral particles of varying composition induce differential chemokine release from epithelial lung cells: importance of physico-chemical characteristics — J. Ovrevik, T. Myran, et al. (2005)
• Physicochemical characterization of cryogenically ground, size separated, fibrogenic particles — P.S. Thorne, E.N. Lightfoot, et al. (1985)
• The ability of mineral dusts and fibres to initiate lipid peroxidation. Part I: parameters which determine this ability — M. Gulumian (1999)
• Asbestos minerals in modern technology — S. Speil, J.P. Leineweber (1969)
• Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres — G. Monchaux, J. Bignon, et al. (1981)

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