Measurements of asbestos burden in tissues

Our plain-English summary of Measurements of asbestos burden in tissues, by R.F. Dodson, M.A. Atkinson (Annals of the New York Academy of Sciences, 2006).

The study

• Authors: R.F. Dodson, M.A. Atkinson
• Journal: Annals of the New York Academy of Sciences
• Published: 2006;1076:281-91
• Cited by: 27 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Asbestos inhaled into the lung is recognized as a potential causal agent for the development of diseases in man. The diseases induced by asbestos include lung cancer, fibrosis of the lung (asbestosis), and extrapulmonary tumors including mesothelioma (a tumor of the serosal membrane), as well as fibrosis and other changes in the pleura linings. The cause of these diseases can often be more specifically linked to asbestos exposure once tissue burden of asbestos is established. The asbestos burden in tissue can be defined as the number of asbestos bodies and/or the numbers and types of asbestos fibers found in the tissue. In either of these cases the quality of information is directly dependent on the preparative techniques and instrumentation used in the analysis. The present article will discuss the significance of findings of tissue burden based on both these variables.

In plain English

This article was a review and methods discussion, not a new study. The authors described what different laboratory techniques can and cannot show about the amount of asbestos in human tissue (the tissue burden): counts of asbestos bodies, which are iron-coated fibers, and of uncoated asbestos fibers. They stated that tissue sections are a very insensitive way to find asbestos bodies, and that dissolving larger tissue samples and collecting the particles on filters gives a better picture. Asbestos bodies form mainly on fibers longer than 8 to 10 micrometres and rarely on chrysotile, so a body count says little or nothing about chrysotile exposure or about the number of uncoated fibers. The light microscope cannot see most uncoated fibers. Analytical transmission electron microscopy can detect the smallest fibers and identify the mineral type. The authors concluded that counts leaving out fibers shorter than 5 micrometres give a biased picture, because short fibers make up most fibers in tissue and are more likely to move to sites outside the lung where asbestos diseases occur.

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 methods discussion of techniques for measuring asbestos in tissue; no new study data
• Who was studied: No study population. Illustrative micrographs show material from human lung tissue, from omentum and mesentery tissue of individuals with mesothelioma, and from dust rinsed from unused brake linings.
• Exposure: Asbestos in tissue, measured as asbestos bodies and as uncoated fibers (chrysotile and amphiboles such as amosite and crocidolite), using light microscopy, scanning electron microscopy and analytical transmission electron microscopy
• Main results:
  • The authors stated that tissue sections are a very insensitive way to identify asbestos bodies, and that digesting larger pieces of tissue gives a better view of the ferruginous body burden.
  • Asbestos bodies form primarily on asbestos fibers longer than 8 to 10 micrometres. The ratio of uncoated fibers to bodies varies widely between individuals, so the authors stated that uncoated fiber numbers cannot be estimated from asbestos body counts.
  • Chrysotile is rarely found as the core of asbestos bodies, so the authors stated that a ferruginous body count gives little or no information on chrysotile exposure.
  • The authors stated that most uncoated fibers in tissue are below the resolution of the light microscope, which also cannot identify fiber type.
  • The scanning electron microscope resolves better than the light microscope. The authors stated it is less suitable than the analytical transmission electron microscope, which can detect the smallest fibers and identify the mineral type.
  • The authors stated that a count limited to fibers 5 micrometres and longer may exclude most fibers in a tissue sample, even when the analytical transmission electron microscope is used.
• The authors' conclusion: The authors concluded that the value of tissue fiber burden data depends on the quality of fiber isolation procedures. They concluded that short fibers (under 5 micrometres) must be included to represent overall burden, because short fibers make up most fibers in tissue and are more likely to relocate to sites outside the lung where asbestos-induced diseases occur.

Topics

Medical terms in this study, explained in our Lexicon: Lung Cancer, Fibrosis, Mesothelioma, Pleura, Asbestos Exposure, Asbestos Bodies.

Related studies

• Analysis of asbestos fiber burden in lung tissue from mesothelioma patients — R.F. Dodson, M. O'Sullivan, et al. (1997)
• Tissue burden of asbestos in nonoccupationally exposed individuals from east Texas — R.F. Dodson, M.G. Williams, et al. (1999)
• Asbestos exposure and ovarian fiber burden — D.S. Heller, R.E. Gordon, et al. (1996)
• Limitations in drawing etiologic inferences based on measurement of asbestos fibers from lung tissue — D.B. Baker (1991)
• Assessment of asbestos burden in the placenta and tissue digests of stillborn infants in South Texas — A.K. Haque, D.M. Vrazel, et al. (1998)
• 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)

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