Comparing biological effects of mineral fibres

Our plain-English summary of Comparing biological effects of mineral fibres, by J. Dunnigan (British Journal of Industrial Medicine, 1989).

The study

• Author: J. Dunnigan
• Journal: British Journal of Industrial Medicine
• Published: 1989;46(10):681-2
• Type of article: Review
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 003668).

In plain English

This is an editorial, not an original study, by an author at the Science Faculty of the University of Sherbrooke, Quebec. The author argued that laboratory comparisons of mineral fibres have usually used equal masses of each fibre. The author suggested that comparing effects by number of fibres may help explain why such results often disagree with human experience. The editorial cited other researchers' work. Davis et al reported more lung fibrosis and tumours in rats inhaling chrysotile than crocidolite or amosite, but the chrysotile dust clouds contained many more fibres longer than 20 microns. Peto's 1986 analysis of Wagner's rat data suggested that the risk per fibre may have been similar for chrysotile and glass wool, and possibly greater for rock wool. In a cell study by Palekar et al, UICC chrysotile needed significantly more fibres than erionite or crocidolite to produce similar cytotoxicity. The author noted scepticism about such retrospective analyses and said other factors, such as chemistry and durability, may also matter. The author concluded that exposure limits expressed in fibre numbers should rest on data reported by fibre number rather than by mass.

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: Editorial (opinion piece discussing other published studies; no new data)
• Who was studied: No study population of its own. The editorial discusses published laboratory studies in rats and in Chinese hamster lung V79 cells, along with human experience of exposure.
• Exposure: Asbestos fibre types (chrysotile, crocidolite, amosite), erionite, and manmade mineral fibres (rock/slag wool, glass wool, glass microfibre), compared on an equal-mass versus equal-fibre-number basis
• Main results:
  • Cited study (Davis et al, rats): more lung fibrosis and tumours after inhalation of chrysotile than after crocidolite or amosite.
  • Cited study (Davis et al): the chrysotile dust clouds contained many more fibres longer than 20 microns than the amphibole dust clouds.
  • Cited analysis (Peto 1986, using Wagner's rat inhalation data): all groups received 10 mg/m3, but the fibre count was more than 10 times higher for chrysotile than for rock wool or glass wool.
  • Cited analysis (Peto 1986): the risk per fibre may have been similar for chrysotile and glass wool, and possibly greater for rock wool.
  • Cited cell study (Palekar et al, Chinese hamster lung V79 cells): UICC chrysotile required significantly more fibres than the other three materials tested to produce similar cytotoxicity.
  • Cited cell study (Palekar et al): both erionite samples required fewer fibres than UICC crocidolite.
  • Cited work (Goldsmith 1986): based on fibre or particle counts, manmade mineral fibres appeared more potent than asbestos for chronic pulmonary disease.
• The authors' conclusion: The author concluded that if exposure limits (TLVs) are expressed in fibre numbers per volume of air, they should be based on scientific data reported by fibre number rather than by mass.
• Limitations the authors state:
  • The author acknowledged scepticism in the scientific community about retrospective conversions of mass doses into fibre numbers.
  • The author stated that the fibre-number observations do not rule out other factors in fibre potency, such as chemical differences and durability.

Related studies

• Comparing biological effects of mineral fibres — J.M. Meijers (1990)
• Sectioning and imaging hard mineral fibres in biological tissues — N.F. Johnson, K. Ibe (1981)
• Health aspects of man-made mineral fibres. A review — J.W. Hill (1977)
• Investigation and analysis of asbestos fibers and accompanying minerals in biological materials — L. Le Bouffant (1974)
• Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres — G. Monchaux, J. Bignon, et al. (1981)
• Lung dust analysis in the assessment of past exposure of man-made mineral fibre workers — J.C. McDonald, B.W. Case, et al. (1990)

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