Asbestos minerals in modern technology

Our plain-English summary of Asbestos minerals in modern technology, by S. Speil, J.P. Leineweber (Environmental Research, 1969).

The study

• Authors: S. Speil, J.P. Leineweber
• Journal: Environmental Research
• Published: 1969;2(3):166-208
• Cited by: 95 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001431).

In plain English

This 1969 article was a review of the mineralogy, chemistry and physics of asbestos minerals and their uses. Its two authors worked at the Johns-Manville Research and Engineering Center. It did not study people or disease. It covered chrysotile, which it said makes up more than 95% of fiber produced, and five amphiboles: crocidolite, amosite, anthophyllite, tremolite and actinolite. The review cited unpublished company analyses. In these, 11 Canadian and US chrysotiles and one anthophyllite had no detectable benzo(a)pyrene. African and Finnish fibers did contain it, up to 150 parts per billion in Cape Province crocidolite. Amphiboles were described as much more resistant to acid than chrysotile. Company brake-wear tests used linings containing 70% chrysotile and estimated that more than 98% of the chrysotile was destroyed in normal braking. A cited study of 22 cosmetic talcum products reported fiber contents of 8 to 30% by count, including tremolite, anthophyllite and chrysotile. The authors concluded that medical investigators should understand the differences between asbestos minerals and how widely they occur, including as impurities in other materials such as talc and in serpentine rock.

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• Design: Review of published and unpublished work on the occurrence, crystal structure, chemistry, physical properties, production and uses of asbestiform minerals; no original human or animal study
• Who was studied: No human subjects; the subjects were asbestiform minerals: chrysotile (serpentine) and five amphiboles (crocidolite, amosite, anthophyllite, tremolite, actinolite), plus talc and serpentine materials containing fibers
• Exposure: Not a study of human exposure; the article described fiber types (chrysotile and amphiboles), commercial grades, products such as asbestos-cement, brake linings, insulation and textiles, and fibrous contaminants in talc and serpentine
• Main results:
  • The authors stated that chrysotile accounts for more than 95% of asbestos fiber produced
  • In work by Reimschussel (unpublished Johns-Manville information) cited in the review, Canadian and US fibers (11 chrysotiles and one anthophyllite) contained no detectable benzo(a)pyrene. Fibers from Africa and Finland did contain it, with the highest concentration, 150 parts per billion, in crocidolite from Cape Province, South Africa
  • The authors suggested that the difference from another study using virgin field samples could mean that at least some benzo(a)pyrene is introduced during processing or shipping of fiber
  • Reviewed studies found chrysotile readily decomposed by strong acids, with a total weight loss of 60%, while amphibole fibers were much more resistant. In a table reproduced from a 1951 source, chrysotile lost 55.69% of its weight after 2 hours refluxing in hydrochloric acid, compared with 4.38% for crocidolite, 12.84% for amosite, 2.66% for anthophyllite, 20.31% for actinolite and 4.77% for tremolite
  • In controlled brake-wear tests performed at the Johns-Manville Research and Engineering Center (cited as unpublished information), passenger car brake linings contained a total of 70% chrysotile. Conservative estimates indicated that more than 98% of the chrysotile was destroyed during normal brake usage. The authors stated that US Public Health Service studies substantiated this for normal driving conditions
  • A cited investigation by Cralley et al. of 22 cosmetic talcum products found fiber contents ranging from 8 to 30% by count of total talc particulates. The fibrous material included tremolite, anthophyllite and chrysotile
  • An electron micrograph of a typical beneficiated industrial talc showed considerable fibrous tremolite
  • A 'museum grade' serpentine specimen from Warren County, New York, appeared under the electron microscope to contain approximately 20% fibers, although optical microscopy showed no chrysotile. The authors stated that electron microscopy reveals that all serpentine rocks contain significant amounts of chrysotile
• The authors' conclusion: The authors concluded that medical investigators of the biologic effects of asbestiform minerals need to understand the diversity among the asbestos minerals and their widespread occurrence, both commercially and as impurities in other materials. In their view, valid medical conclusions require relating biologic evidence to variations in fiber size, form, strength, surface reactions, chemical reactivity and associated impurities
• Limitations the authors state:
  • The authors noted that the discussion of surface characteristics mostly concerned chrysotile, because the amphiboles had received much less study

Topics

Medical terms in this study, explained in our Lexicon: Asbestos.

Related studies

• The ability of mineral dusts and fibres to initiate lipid peroxidation. Part I: parameters which determine this ability — M. Gulumian (1999)
• Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres — G. Monchaux, J. Bignon, et al. (1981)
• The detection and localization of mineral fibers in tissue — C. Berkley, J. Churg, et al. (1965)
• Characterization of talc and associated minerals — D.H. Hamer, F.R. Rolle, et al. (1976)
• Sepiolite asbestos from Franklin, New Jersey: a case study in medical geology — M. Germine (1987)
• Modern carbonate microbialites from an asbestos open pit pond, Yukon, Canada — I.M. Power, S. Wilson, et al. (2011)

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