Dust Chemistry and Physics - Mineral and Vitreous Fibres

Our plain-English summary of Dust Chemistry and Physics - Mineral and Vitreous Fibres, by J.P. Leineweber (1980).

The study

• Author: J.P. Leineweber
• Published: BIOLOGICAL EFFECTS OF MINERAL FIBRES (J.C. WAGNER, EDITOR), LYON: IARC SCIENTIFIC PUBLICATIONS, VOLUME 30, PP. 881-900 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This article was a review, not an original study. The author described the chemistry and physics of non-asbestos fibres: man-made vitreous fibres, synthetic crystalline fibres, and natural mineral fibres such as wollastonite, attapulgite, sepiolite, amphiboles and zeolites. Citing others' animal studies, the author listed fibres reported to produce malignant tumours after implantation into the pleural or peritoneal cavities. The author wrote that no consistent cause of biological activity other than fibre dimensions could be found. The author also cited reports that milling shortened glass fibres without thinning them, and that airborne levels in five mineral wool plants ranged from under 0.1 to 0.8 fibres per ml. The author concluded that composition and surface chemistry, if they matter, are secondary. The author concluded that airborne concentrations of fibre-shaped particles of possibly biologically active size cannot be predicted, only obtained by careful sampling followed by microscopic counting and measuring. The author noted that animal studies on fibre dimensions gave no data on bronchogenic cancer and scant data on fibrosis, and that very little was known about fibre durability in the body.

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 review and discussion paper (conference contribution); no original data collected
• Who was studied: No human or animal population. The review covered non-asbestos fibrous materials: man-made vitreous fibres (glass, mineral wool, refractory aluminium silicate fibre), synthetic crystalline fibres (alumina, silicon carbide, sodium aluminium carbonate, potassium titanate, graphite) and natural mineral fibres (wollastonite, attapulgite, sepiolite, amphiboles, zeolites).
• Exposure: Fibre dose, fibre dimensions and fibre durability in the body, discussed as the determinants of biological activity
• Main results:
  • The author listed fibres reported, in other researchers' animal studies, to produce malignant tumours after implantation in the pleural or peritoneal cavities. The list was amosite, anthophyllite, chrysotile, crocidolite, tremolite, wollastonite, attapulgite, borosilicate glass, aluminium silicate glass, mineral wool, aluminium oxide, potassium titanate, silicon carbide and sodium aluminium carbonate.
  • Citing Stanton et al. (1977), the author reported that fibres longer than 8 µm and thinner than 1.5 µm in diameter had the greatest biological activity in those animal implantation experiments.
  • The author wrote that no consistent cause of biological activity other than fibre dimensions could be found.
  • The author disagreed with Bertrand and Pezerat's conclusion that carcinogenic activity rises continuously with the fibres' aspect ratio.
  • Citing Assuncao and Corn (1975), the author reported that milling glass fibres reduces their length with essentially no effect on their diameter.
  • Citing Esmen et al. (1978), who studied five mineral wool manufacturing plants, the author reported airborne fibre concentrations ranging from less than 0.1 to as high as 0.8 fibres per ml across operations.
  • Citing Dodgson et al., the author reported results for production operations in several European plants. Concentrations were lower in glass-fibre plants than in mineral-wool plants (0.013 versus 0.040 fibres per ml). The overall average for secondary processes was 0.071 fibres per ml.
  • The author stated there is no practical way to predict airborne concentrations of fibre-shaped particles with dimensions that might be considered biologically active. The author wrote that the necessary information can only be obtained through careful sampling of the environment, followed by careful microscopic counting and measuring.
• The authors' conclusion: The author concluded that fibre dimensions are the main determinant of biological activity. Bulk composition or surface chemistry, if they play a role at all, are secondary.
• Limitations the authors state:
  • In discussing the animal experiments relating fibre dimensions to biological activity, the author stated there were no data relating to bronchogenic cancer and only scant data on fibrogenesis.
  • The author noted that the animal experiments produced tumours using very artificial means of bringing fibres into contact with tissue.
  • The author stated that very little is known about the biological durability of fibres. The author added that it was too early to say whether the author's own laboratory approach to measuring durability would succeed.

Topics

Medical terms in this study, explained in our Lexicon: Vitreous, Crystalline, Wollastonite, Palygorskite (Attapulgite), Sepiolite, Amphibole Group, Zeolite, Bronchogenic Carcinoma.

Browse return to medical research.