Studies on surface properties of asbestos. II. Role of dimensional characteristics and surface properties of mineral fibers in the induction of pleural tumors

Our plain-English summary of Studies on surface properties of asbestos. II. Role of dimensional characteristics and surface properties of mineral fibers in the induction of pleural tumors, by L. Bonneau, C. Malard, H. Pezerat (Environmental Research, 1986).

The study

• Authors: L. Bonneau, C. Malard, H. Pezerat
• Journal: Environmental Research
• Published: 1986;41(1):268-75
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In animal experiments, the probability that pleural tumors will develop after mineral fiber implantation is dependent upon the fiber's size. This was originally analyzed in relation to the number of injected fibers with specific dimensional characteristics and, more recently, in relation to average aspect ratio (average length/diameter ratio). New experimental data on various mineral fibers suggest that the carcinogenic potency of a solid particle depends on two parameters: the nature of the mineral and therefore the nature of active surface sites, and the aspect ratio of the particle. These two parameters can intervene in a mechanism of model reaction involving the basic properties of lateral faces of fibers.

In plain English

This paper reported no new animal experiments. The authors reanalyzed published results from pleural implantation experiments by Stanton and colleagues, plus measurements supplied by R. C. Brown. They asked how average fiber length-to-diameter ratio (aspect ratio) and mineral type related to estimated pleural tumor probability. Using least-squares fitting, they found a very poor fit for crocidolite (13 samples) and the closest fits for dawsonite (6 samples) and alumina (8 samples). At an average aspect ratio of 20, the estimated tumor probability was about 12% for alumina, 18% for glass fibers, 50% for dawsonite and 100% for tremolite. The tremolite curve was suggested from only two data points. Too few samples were available to analyze amosite, talc and several other minerals separately, and no chrysotile results were available. The authors concluded that the animal results lent support to their proposed model, in which two parameters govern fiber activity: for fibers of the same size, the density and strength of donor sites on the fiber surface; and for fibers of the same crystal-chemical nature, the aspect ratio.

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: statistical reanalysis of previously published animal pleural implantation data (no new experiments)
• Who was studied: fiber samples from pleural implantation experiments in animals by Stanton et al. (1977, 1981), with additional dawsonite data from R. C. Brown. Separate comparison was possible for crocidolite (13 samples), dawsonite (6 samples) and alumina (8 samples), with glass fiber results taken from earlier work. Only limited comparison was possible for wollastonite, tremolite and potassium titanate.
• Exposure: pleural implantation of mineral fiber samples of equal weight (40 mg) but different size distributions. The fibers included crocidolite, tremolite, dawsonite, alumina, glass fibers and potassium titanate, among others. Samples were characterized by the number of fibers longer than 8 micrometers and thinner than 0.25 micrometers, or by average aspect ratio.
• Main results:
  • For crocidolite (13 samples), the fit between fiber dimensions and tumor probability was very poor
  • The highest correlations between average aspect ratio and tumor probability were for dawsonite (6 samples) and alumina (8 samples)
  • At the same average aspect ratio, dawsonite fibers showed higher carcinogenic activity than glass or alumina fibers, and tremolite fibers were probably the most active
  • At an average aspect ratio of 20, the estimated pleural tumor probability was about 12% for alumina, 18% for glass fibers, 50% for dawsonite and 100% for tremolite
  • The average aspect ratio giving a 50% tumor probability was about 4 for tremolite, 20 for dawsonite, 138 for glass fiber and 220 for alumina fiber
  • For dawsonite, tumor probability rose very rapidly beyond an average aspect ratio of about 12
  • Four different dawsonite data sets gave curves whose differences were minor compared with the differences between dawsonite and other fibers
• The authors' conclusion: The authors concluded that the study of the animal results lent support to their proposed model of fiber carcinogenic action, in which two parameters govern fiber activity. For fibers of the same size, the parameter is the density and strength of donor surface sites. For fibers of the same crystal-chemical nature, it is the aspect ratio. They also stated that the nature of the material plays a major role in carcinogenic activity.
• Limitations the authors state:
  • Too few samples to analyze amosite, halloysite, attapulgite, K-titanate and talc separately
  • No results were available for chrysotile and only limited results for crocidolite
  • Changes in amphibole fiber dimensions after implantation may explain the poor crocidolite correlation
  • The tremolite curve is not based on fitted experimental data but suggested from two points

Topics

Medical terms in this study, explained in our Lexicon: Mineral Fiber, Aspect Ratio (Length-to-diameter ratio), Carcinogenic.

Related studies

• Surface characteristics of asbestos fibers released from asbestos- cement products — J.A. Helsen, P. van de Velde, et al. (1989)
• Probing anisotropic surface properties and interaction forces of chrysotile rods by atomic force microscopy and rheology — D. Yang, L. Xie, et al. (2014)
• Man-made mineral fiber hazardous properties assessment using transgenic rodents: example of glass fiber testing — M.C. Bottin, J.C. Vigneron, et al. (2003)
• High aspect ratio materials: role of surface chemistry vs. length in the historical "long and short amosite asbestos fibers" — M. Tomatis, F. Turci, et al. (2010)
• Induction of heme oxygenase in mammalian cells by mineral fibers: distinctive effect of reactive oxygen species — K. Suzuki, T.K. Hei (1996)
• Putative inhibitory effects of chrysotile, crocidolite, and amosite mineral fibers on the more complex surface membrane glycolipids and glycoproteins — H.A. Newman, Y.A. Saat, et al. (1980)

Browse more research in Environmental Research, or return to medical research.