Quantitative comparison of asbestos and talc bodies in an individual with mixed exposure

Our plain-English summary of Quantitative comparison of asbestos and talc bodies in an individual with mixed exposure, by R.F. Dodson, M. O'Sullivan, C.J. Corn, et al (American Journal of Industrial Medicine, 1995).

The study

• Authors: R.F. Dodson, M. O'Sullivan, C.J. Corn, S.P. Hammar
• Journal: American Journal of Industrial Medicine
• Published: 1995;27(2):207-15
• Type of article: Case report
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Tissue from an individual with a history of exposure to asbestos and other dust was referred for particulate analysis. The digested material was reviewed by light microscopy to establish the numbers of ferruginous bodies per gram of tissue. Typical asbestos bodies were found at levels consistent with occupational exposure. A second type of elongated ferruginous body was formed on a thicker transparent core which suggested the minerals were sheet silicates. The number of ferruginous bodies with nonasbestos cores was over four times the number of asbestos cored ferruginous bodies. Electron microscopy was used to confirm the core composition of both populations and also to establish the levels of uncoated fibers. The nonasbestos ferruginous bodies were predominantly formed on talc.

In plain English

This case report described lung tissue from a 59-year-old man who had smoked 50 to 75 pack-years. He reported asbestos exposure removing insulation from naval aircraft (1943 to 1945) and working with insulation of ship piping (1947 to 1969). Later exposures were presumed to be linked to work at automotive repair centers. He had also worked 16 years in a dusty tire distribution area. He died of a metastatic lung cancer, diagnosed at autopsy as adenocarcinoma, probably bronchogenic. The authors counted coated particles called ferruginous bodies in dissolved lung tissue by light microscopy and identified their cores by electron microscopy. Bodies on thin asbestos-type cores numbered 1,600 per gram of dried lung, a level the authors said reflects occupational exposure. Bodies on thicker non-asbestos cores numbered 7,500 per gram of dried lung, and these were predominantly formed on talc. The asbestos cores identified were amosite and tremolite. Only two uncoated fibers were found, one amosite and one tremolite, equal to 305 fibers per gram of dried lung. The authors concluded the man had mixed exposure to asbestos and talc. They noted that some talc bodies can be hard to tell apart from asbestos bodies.

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: Case report (quantitative lung tissue analysis of one individual at autopsy)
• Who was studied: One 59-year-old man with a 50-75 pack-year cigarette smoking history and a stated history of significant asbestos exposure. He died of a metastatic lung neoplasm (autopsy diagnosis: moderately to poorly differentiated adenocarcinoma, probably bronchogenic). Tissue from seventeen sites of peripheral lung was pooled (0.4475 g dry, 2.4189 g wet).
• Exposure: Reported asbestos exposure came from removal of insulation from the fuselage and cockpits of naval aircraft (1943-1945) and working with insulation of piping in ships (1947-1969). Later exposures were presumed to be associated with working at automotive repair centers. He also worked 16 years in a dusty tire distribution area, where the authors presumed the dust included talc.
• Main results:
  • Light microscopy: ferruginous bodies on thin transparent cores, counted as asbestos bodies, numbered 1,600 per gram dry lung (290 per gram wet).
  • Light microscopy: ferruginous bodies on thicker non-asbestos cores, considered sheet silicates, numbered 7,500 per gram dry lung (700 per gram wet).
  • Total ferruginous bodies of both types numbered 9,100 per gram dry lung (990 per gram wet).
  • Electron microscopy showed that the non-asbestos ferruginous bodies were predominantly formed on talc.
  • High-magnification transmission electron microscopy of 0.48 mm2 of filter found no uncoated fibers (detection limit 242,000 fibers per gram dry, 45,000 per gram wet).
  • A lower-magnification scan of 7.5 mm2 found two uncoated fibers, one amosite and one tremolite. This gave an uncoated asbestos burden of 305 fibers per gram dry (56 per gram wet).
  • Of nine ferruginous bodies found in the analytical transmission electron microscopy scan, one was formed on amosite, one on tremolite, and seven on talc.
  • By scanning electron microscopy, 15 ferruginous bodies were found. Eight had talc cores, four had silicon cores, two were completely coated (organic or iron cores), and one had a tremolite core.
  • Nine ferruginous bodies were transferred and stripped of their coating. Six of the cores were amosite asbestos and three were fibrous talc.
  • The authors described the small number of short uncoated fibers, relative to the number of ferruginous bodies, as unexpected.
• The authors' conclusion: The authors concluded that the patient had a mixed dust exposure to both asbestos and talc, based on the composition and numbers of ferruginous bodies. They stated that the asbestos body levels reflect occupational levels.
• Limitations the authors state:
  • The authors stated that some ferruginous bodies formed on sheet silicates, including talc, can be difficult to distinguish from asbestos bodies.
  • Some ferruginous bodies were totally coated, which obscured the core material.
  • The method of relocating bodies for coat removal preferentially selected larger ferruginous bodies.
  • The source of the talc (tire dust) was presumed, not established.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Talc, Ferruginous Bodies, Asbestos Bodies, Occupational Exposure, Ferruginous body, Silicate.

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• Quantitative analysis of asbestos burden in a series of individuals with lung cancer and a history of exposure to asbestos — R.F. Dodson, D.R. Brooks, et al. (2004)
• Mineralogical features associated with cytotoxic and proliferative effects of fibrous talc and asbestos on rodent tracheal epithelial and pleural mesothelial cells — A.G. Wylie, H.C. Skinner, et al. (1997)
• Characterization of talc and associated minerals — D.H. Hamer, F.R. Rolle, et al. (1976)
• Tissue burden evaluation of elongated mineral particles in two individuals with mesothelioma and whose work history included manufacturing tile — R.F. Dodson, L.W. Poye (2020)

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