Relationships between ferruginous bodies and uncoated asbestos fibers in lung tissue

Our plain-English summary of Relationships between ferruginous bodies and uncoated asbestos fibers in lung tissue, by R.F. Dodson, M. O'Sullivan, C.J. Corn (Archives of Environmental Health, 1996).

The study

• Authors: R.F. Dodson, M. O'Sullivan, C.J. Corn
• Journal: Archives of Environmental Health
• Published: 1996;51(6):462-6
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Tissue was obtained from two American groups. The tissue was defined by ferruginous body levels of either < or = 1000 or > 1000 ferruginous bodies/g dry weight, and tissue was evaluated by light microscopy and analyzed by analytical transmission electron microscopy. Tissue was bleach digested, and uncoated asbestos fibers were classified with respect to type and size. In addition, some ferruginous body cores were analyzed. There was a wide range of uncoated fibers associated with each ferruginous body. A relationship was found between amosite fibers and ferruginous bodies. Other asbestos types were not associated significantly with the development of ferruginous bodies. Uncoated crocidolite fibers were not detected in these samples; this result further emphasizes the under-appreciated exposure of Americans to amosite. The levels of ferruginous bodies in both groups suggest exposures above those expected in the general population. Uncoated chrysotile levels were below the ranges reported previously for some general populations. The data suggest that there is a wide variation in the ratio of uncoated to coated fibers and that the amphibole in the United States is more likely to be amosite than crocidolite.

In plain English

This laboratory study compared ferruginous bodies (coated fibers, only some of whose cores were analyzed) with uncoated asbestos fibers in lung tissue from 20 people in the United States with suspected or confirmed past asbestos exposure. Most had worked with asbestos-containing products, but none had worked in primary asbestos manufacturing. They were split into two groups of 10 by coated bodies per gram of dry lung: 1,000 or fewer, or more than 1,000. Coated bodies were counted by light microscopy and uncoated fibers by electron microscopy. Everyone in the higher group had uncoated amosite fibers long enough to form coated bodies. The coated-body cores analyzed in that group were amosite, except one crocidolite core. No uncoated crocidolite was found in anyone. The ratio of uncoated asbestos fibers to coated bodies ranged from 13:1 to 361:1 in the higher group, and from none detected to 597:1 in the lower group. Nonasbestos fibers were often the most common fiber type. The authors concluded that coated bodies in people with mixed-fiber exposures suggest past amosite exposure. They reported that these people's chrysotile levels were lower than earlier general-population reports, and said this remained unexplained.

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: Lung tissue analysis study in two groups of 10 subjects. It compared ferruginous body counts made by light microscopy with the type and size of uncoated fibers measured by analytical transmission electron microscopy. The cores of some ferruginous bodies were also analyzed.
• Who was studied: 20 individuals from the United States (ages 51 to 85, 18 men and 2 women) with suspected or confirmed past asbestos exposure. They were divided into two groups of 10 by ferruginous body count: 1,000 or fewer per gram dry weight (cases 1-10, called 'paraoccupational') and more than 1,000 per gram (cases 11-20, called 'occupational'). Diagnoses included mesothelioma, asbestosis, lung cancer and other conditions.
• Exposure: Mostly work with asbestos-containing products (for example insulator, shipyard worker, construction, electrician; one wife of a shipyard worker). None had worked in a primary asbestos-manufacturing facility. Fiber types measured in tissue were amosite, chrysotile, crocidolite, tremolite/actinolite, anthophyllite and nonasbestos fibers.
• Main results:
  • All 10 patients in the group with more than 1,000 ferruginous bodies per gram had uncoated amosite fibers long enough to form ferruginous bodies.
  • In the group with more than 1,000 ferruginous bodies per gram, all ferruginous body cores analyzed were amosite, except one formed on crocidolite (case 11).
  • No uncoated crocidolite fibers were detected in any of the 20 specimens.
  • The ratio of total uncoated asbestos fibers to ferruginous bodies ranged from 13:1 to 361:1 in the group with more than 1,000 per gram, and from nondetectable to 597:1 in the group with 1,000 or fewer per gram.
  • Across both groups, all but one chrysotile fiber were too thin to be seen by light microscopy.
  • In both groups, nonasbestos fibers were often the predominant fiber type. No man-made fibers were found.
• The authors' conclusion: The authors concluded that ferruginous bodies in people with mixed-fiber asbestos exposures suggest past amosite exposure. They found chrysotile levels in these individuals appreciably lower than previously reported for the general population, a finding they called unexplained. They also stated that their results suggest it is not appropriate to assume a correlation between numbers of coated and uncoated fibers in tissue, whatever the fiber type.

Topics

Medical terms in this study, explained in our Lexicon: Ferruginous Bodies, Ferruginous body, Analytical Transmission Electron Microscopy (ATEM), Amosite, Crocidolite, Chrysotile, Amphibole Group.

Related studies

• The association among ferruginous body, uncoated fibers, asbestos and non-asbestos fibers in lung tissue in terms of length — T. Suzuki, Y. Sakakibara, et al. (2016)
• Ferruginous bodies: implications in the mechanism of fiber and particle toxicity — A.J. Ghio, A. Churg, et al. (2004)
• A comparison of the ferruginous body and uncoated fiber content in the lungs of former asbestos workers — R.F. Dodson, M.G. Williams, et al. (1985)
• Analysis of ferruginous bodies in bronchoalveolar lavage from foundry workers — R.F. Dodson, M. O'Sullivan, et al. (1993)
• 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)
• Ferruginous bodies as markers of environmental exposure to inorganic particles: experience with 270 autopsy cases in Mexico — F.J. Arenas-Huertero, M. Salazar-Flores, et al. (1994)

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