Asbestos bodies in lung tissue following exposure to crocidolite

Our plain-English summary of Asbestos bodies in lung tissue following exposure to crocidolite, by V. Williams, N.H. de Klerk, D. Whitaker, et al (American Journal of Industrial Medicine, 1995).

The study

• Authors: V. Williams, N.H. de Klerk, D. Whitaker, A.W. Musk, K.B. Shilkin
• Journal: American Journal of Industrial Medicine
• Published: 1995;28(4):489-95
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

A series of 206 necropsies in Western Australia (WA) have had routine counts made of asbestos bodies in samples of lung tissue using conventional light microscopy. Thirty-two cases had worked in the asbestos industry at Wittenoom, WA and (log) counts of asbestos bodies in their lung tissue correlated well with estimates of their (log) cumulative airborne exposure to crocidolite fibers (r = 0.60). There was no association between the number of asbestos bodies and time since exposure to asbestos ceased. In subjects without known exposure to asbestos, there was a weak but nonsignificant increase in number of asbestos bodies with increasing age, with 26% of cases having no asbestos bodies present. It is concluded that the relatively simple technique of light microscopy for counting of asbestos bodies in lung tissue provides a reliable indication of the level of past occupational exposure to crocidolite in subjects whose exposure has been only to crocidolite. This could be extremely useful in follow-up studies of cohorts that lack reliable measures of airborne exposure to crocidolite asbestos.

In plain English

This Western Australian necropsy (autopsy) study counted asbestos bodies in lung tissue from 206 people by light microscopy. Asbestos bodies are asbestos fibers that have become coated inside the body. Thirty-two were former male workers at the Wittenoom crocidolite (blue asbestos) mine and mill, with detailed exposure histories. Counts ranged from 0 to 200,000 per gram of wet lung, highest in former Wittenoom workers. Among these workers, the log of estimated cumulative exposure and the log of asbestos body counts were correlated (r = 0.60). After allowing for cumulative exposure, time since exposure ceased, time since first exposure, work site, intensity of exposure and age had no significant effect on counts. Among unexposed subjects without asbestos-related disease, counts rose weakly with age, but not significantly (p = 0.13); including unexposed subjects with asbestos-related disease gave similar results. Of subjects without known exposure, 26% had no asbestos bodies. The authors concluded that light-microscope counts reliably indicate past occupational exposure in people exposed only to crocidolite. They noted that counts alone cannot separate light exposure from none, and are unlikely to help with mixed asbestos types.

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: Necropsy (autopsy) survey of asbestos body counts in lung tissue, using light microscopy
• Who was studied: 206 necropsy cases in Western Australia. These were 32 former male Wittenoom employees aged 42 to 77, 78 subjects with some suspicion of asbestos involvement in their deaths, and 96 subjects without asbestos-related disease or exposure.
• Exposure: Crocidolite, from mining and milling at Wittenoom. The 32 former workers had detailed exposure histories, including airborne fiber levels and dates of work, used to estimate cumulative exposure.
• Main results:
  • Across all 206 subjects, asbestos body counts ranged from 0 to 200,000 per gram of wet lung, with the highest values in former Wittenoom workers.
  • Among the 32 Wittenoom workers, the log of cumulative exposure and the log of asbestos bodies per gram showed a linear relationship with a correlation coefficient of 0.60.
  • Among the Wittenoom workers, time since ceasing exposure, time since first exposure, work site, intensity of exposure and age had no significant effect on body count (p greater than 0.30 for all).
  • The authors describe this lack of effect of age and time since first or last exposure among the Wittenoom workers as applying after adjustment for cumulative exposure.
  • Among unexposed subjects, counts rose weakly with age, but the relationship was not statistically significant (p = 0.13).
  • This p = 0.13 relationship was among unexposed subjects without asbestos-related disease. It remained similar when unexposed subjects with asbestos-related disease were included.
  • Among subjects without known exposure, 26% had no asbestos bodies present.
  • 22 exposed subjects had fewer than 100 asbestos bodies per gram. Two supposedly unexposed subjects had 100 or more.
  • In the five cases of malignant mesothelioma with no known history of asbestos exposure, counts ranged from 1 to 25 asbestos bodies per gram.
• The authors' conclusion: The authors concluded that counting asbestos bodies in lung tissue by light microscopy provides a reliable indication of the level of past occupational exposure to crocidolite in people exposed only to crocidolite. They added that it could be useful for cohorts lacking reliable airborne exposure measures.
• Limitations the authors state:
  • Asbestos body counts alone were not sensitive enough to distinguish light exposure to crocidolite from no exposure, given the many zero readings.
  • Smoking history was available for only a limited number of subjects and was ignored.
  • Asbestos body counts are unlikely to be very helpful in estimating exposure to mixtures of asbestos types.
  • Chrysotile (white asbestos) does not generally form asbestos bodies.
  • For the two supposedly unexposed subjects with high counts, the authors could not verify possible exposure.

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Wittenoom, Western Australia

All asbestos mines

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Crocidolite.

Medical terms in this study, explained in our Lexicon: Asbestos Bodies, Crocidolite, Wittenoom, Occupational Exposure.

Related studies

• Comparison of measures of exposure to asbestos in former crocidolite workers from Wittenoom Gorge, W. Australia — N.H. de Klerk, A.W. Musk, et al. (1996)
• Biopersistences of man-made vitreous fibers and crocidolite fibers in rat lungs following short-term exposures — R.P. Musselman, W.C. Miiller, et al. (1994)
• Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure — D.M. Bernstein, R.A. Rogers, et al. (2015)
• Comparison of functional, biochemical, and morphometric alterations in the lungs of 4 rat strains and hamsters following repeated intratracheal instillation of crocidolite asbestos — D.J. Padilla-Carlin, D.L. Costa (2011)
• Crocidolite and mesothelioma — F. Schneider, T.A. Sporn, et al. (2008)
• Asbestos bodies: clues to the mechanism of asbestos toxicity? — A.B. Kane (2003)

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