Method for removing the ferruginous coating from asbestos bodies

Our plain-English summary of Method for removing the ferruginous coating from asbestos bodies, by R.F. Dodson, M.G. Williams, G.A. Hurst (Journal of Toxicology and Environmental Health, 1983).

The study

• Authors: R.F. Dodson, M.G. Williams, G.A. Hurst
• Journal: Journal of Toxicology and Environmental Health
• Published: 1983;11(4-6):959-66
• Cited by: 18 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

A new technique for removing the ferruginous coating from ferruginous bodies is described. The tissue from occupationally exposed individuals was digested in bleach and the material collected on a Nucleopore filter. The ferruginous bodies were localized by light microscopy and either cleaned on the marked filter or transferred to a marked area on a clean filter. The chemical treatment consisted of an 8% oxalic acid bath used at various temperatures. It was determined that at 75 degrees C the reaction resulted in removal of the ferruginous coat, leaving an exposed core for further analysis. This procedure overcomes the previous analytical problems of core analysis caused by the ferruginous coating.

In plain English

This laboratory methods paper described a way to strip the iron-rich ('ferruginous') coating from ferruginous bodies, which are coated fibers found in lung tissue, so that the fiber core inside can be analyzed. The authors explained that this coating can interfere with core analysis. They dissolved small samples of formalin-fixed lung tissue from six occupationally exposed individuals in bleach and collected the bodies on filters. They then treated the bodies for 4 hours with 8% oxalic acid at room temperature, 45°C or 75°C and examined them by scanning electron microscopy with X-ray analysis. At room temperature, the bodies ranged from apparently unaltered to having little left besides the core. At 45°C, no intact bodies remained. At about 75°C, the coating was totally removed from all bodies. Over 442 cleaned cores were studied. In a comparison of 50 untreated amosite fibers with 50 treated cores, the authors found no change in chemical composition from the acid. The authors concluded that the technique is reproducible. They noted that their X-ray comparison was empirical rather than quantitative.

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: laboratory methods study (technique for removing the coating from ferruginous bodies taken from human lung tissue)
• Who was studied: formalin-fixed lung tissue from six occupationally exposed individuals, previously confirmed to contain abundant ferruginous bodies; place and dates not stated
• Exposure: The individuals' occupational exposure is not described further. The laboratory treatment studied was 8% oxalic acid for 4 hours at room temperature, 45°C or 75°C. Treated cores were compared with untreated amosite asbestos as a control.
• Main results:
  • At room temperature, treated bodies ranged from apparently unaltered, to partially cleaned, to having little material left other than the core
  • At 45°C, no intact ferruginous bodies remained; all were cleaned completely or most cores were uncoated
  • At approximately 75°C, the coating was totally removed from all bodies, with only occasional aluminosilicate aggregates remaining on the cores
  • The iron peak from a cleaned amosite core was comparable to that of control amosite. In a comparison of 50 untreated amosite fibers with 50 treated cores, the X-ray data indicated no change in chemical composition from the oxalic acid treatment.
  • Over 442 cleaned cores were studied as the basis for judging reproducibility
  • When areas of a filter were simply circled, electron microscopy showed more fibers than the number of ferruginous bodies seen by light microscopy. The authors therefore moved individual bodies to marked areas on clean filters.
• The authors' conclusion: The authors concluded that the technique is a reproducible method for removing the coating from ferruginous bodies and resolves the earlier problem of analyzing the cores
• Limitations the authors state:
  • The X-ray composition comparison was empirical, because the authors' analyzer was not equipped for quantitative analysis

Topics

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

Related studies

• Analysis of cores of ferruginous bodies from former asbestos workers — R.F. Dodson, M.F. O'Sullivan, et al. (1982)
• A method for extracting ferruginous bodies from sputum and pulmonary tissue — M.J. Smith, B. Naylor (1972)
• A simple method for preparing ferruginous bodies for electron microscopic examination — A. Churg, N. Sakoda, et al. (1977)
• Fibrous dust particles and ferruginous bodies. Methods for quantitating them and some results from the lungs of city dwellers — P. Gross, J. Tuma, et al. (1970)
• A procedure for the isolation of amosite asbestos and ferruginous bodies from lung tissue and sputum — M.G. Williams, R.F. Dodson, et al. (1982)
• Pulmonary fibrosis and ferruginous bodies associated with exposure to synthetic fibers — A.J. Ghio, W. Funkhouser, et al. (2006)

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