Misleading "New Insights into the Chrysotile Debate"

Our plain-English summary of Misleading "New Insights into the Chrysotile Debate", by H.J. Woitowitz, X. Baur (Pneumologie, 2018).

The study

• Authors: H.J. Woitowitz, X. Baur
• Journal: Pneumologie
• Published: 2018;72(7):507-513
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Although there is no dispute among independent scientists about the carcinogenic and fibrogenic effects of chrysotile, the asbestos industry has been continuously and successfully acting to cast doubts on its harm. Another approach including asbestos insurance entities is to refuse compensation by raising the bar and fight criminal prosecution for asbestos-related diseases by the help of paid scientists. A recent publication on asbestos fibre burden in human lungs fits well in this context. The claim that chrysotile fibres are biopersistent in human lung is not based on the data provided by these authors, and, additionally, exhibits serious inconsistencies and obvious mismeasurements and significant methodological problems. The conclusion of the authors that fibre analysis of workers' lungs "is of high significance for differential diagnosis, risk assessment and occupational compensation" is unfounded and reprehensible. Also the available literature, the statements of the WHO, IARC, other decisive independent international organizations, and all our experience provide abundant evidence to the contrary. Note, the method is generally restricted to research only and is not recognized for diagnostic purpose and compensation in any other country. In conclusion, fibre counting in lung tissues should not be used to estimate former exposure to chrysotile comprising c. 94 % of applied asbestos in Germany. The authors claim that the analyses can improve the compensation rates in Germany. However, the opposite has been the case; it significantly worsens the non-justified denial of well-substantiated compensation claims.

© Georg Thieme Verlag KG Stuttgart · New York.

In plain English

This article is a "Point of View" commentary, not a new study. The authors criticised a 2017 paper by Feder et al. that claimed chrysotile asbestos fibres persist in human lungs. The authors argued that this claim rested on only 6 patients examined at autopsy and on data with inconsistencies, such as far more asbestos bodies than free fibres. They cited their own earlier electron-microscope analyses. In lung tissue from 10 asbestos-exposed workers, on average only 2% of asbestos bodies contained chrysotile, although chrysotile made up about 94% of asbestos used in German workplaces. In 47 patients with malignant mesothelioma, amphibole fibre concentrations were about 10 times higher than chrysotile. They also cited a study by Schneider et al. of 257 patients in which, with more than 30 years since exposure, more than half had no detectable chrysotile. The authors argued that lung fibre counts worsen unjustified denial of compensation claims. They noted that only about 800 of roughly 4,000 yearly asbestos lung cancer claims in Germany were accepted. They concluded that the Feder et al. article was "irreparably flawed."

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: Point of View commentary (critique of another group's published study, Feder et al.), drawing on the authors' earlier work and the literature; no new data
• Who was studied: The critiqued study (Feder et al.) reported fibre analysis in 6 patients at autopsy. The authors refer to their own institute's experience analysing lung specimens of more than 350 patients with and 150 without occupational asbestos exposure in Giessen, Germany
• Exposure: Chrysotile compared with amphibole asbestos (crocidolite, amosite, anthophyllite, tremolite, actinolite) in lung tissue; chrysotile was about 94% of asbestos used in German workplaces
• Main results:
  • The authors' criticism of Feder et al.: their conclusion rested on only 6 patients examined at autopsy
  • The authors' criticism of Feder et al.: their data showed far more asbestos bodies than free fibres (e.g. 500 : 0 and 1900 : 0 in samples of patient 1), contrary to a known ratio of about 1:1000
  • The authors' criticism of Feder et al.: their data showed variation of up to a factor of 5 between samples from the same patient
  • Authors' earlier ARTEM study of 10 workers (134 asbestos bodies): on average only 2% of asbestos bodies contained chrysotile fibres (mean 2.2%, range 0 to 8%). About 95% would be expected if chrysotile were biopersistent
  • Authors' earlier study of 47 malignant mesothelioma patients: amphibole fibre concentrations were about 10 times higher than chrysotile. Geometric means in million fibres per gram dry lung tissue were 2.28 amphibole vs 0.26 chrysotile for fibres under 5 µm, and 0.34 vs 0.03 for fibres over 5 µm
  • Cited study by Schneider et al. of 257 asbestos-exposed patients: with interim periods of more than 30 years, more than 50% had no detectable chrysotile fibres
  • German compensation figures cited by the authors: of about 4,000 asbestos lung cancer compensation claims per year, only about 800 (c. 20%) were accepted in recent years. The authors argued that fibre analyses worsen unjustified denial of claims
  • The authors stated that Feder et al.'s conflict of interest declarations did not disclose their financial conflicts of interest
• The authors' conclusion: The authors concluded that the Feder et al. article is irreparably flawed. In their view, its claims are consistent neither with its own findings nor with literature showing that chrysotile, unlike amphiboles, is rapidly cleared from the lungs

Topics

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

Medical terms in this study, explained in our Lexicon: Chrysotile, Carcinogenic, Fibrogenic, Differential Diagnosis, IARC.

Related studies

• The asbestos fibre burden in human lungs: new insights into the chrysotile debate — I.S. Feder, I. Tischoff, et al. (2017)
• Correspondence regarding the article "The asbestos fibre burden in human lungs: new insights into the chrysotile debate" — L.C. Oliver, F. Belpoggi, et al. (2017)
• Correspondence regarding the article "The asbestos fibre burden in human lungs: new insights into the chrysotile debate" — I.S. Feder, I. Tischoff, et al. (2017)
• Correspondence regarding the article "The asbestos fibre burden in human lungs: new insights into the chrysotile debate" — P. Sartorelli (2017)
• Effects of Chrysotile Exposure in Human Bronchial Epithelial Cells: Insights into the Pathogenic Mechanisms of Asbestos-Related Diseases — G.R. Gulino, M. Polimeni, et al. (2016)
• New insights into the toxicity of mineral fibres: A combined in situ synchrotron μ-XRD and HR-TEM study of chrysotile, crocidolite, and erionite fibres found in the tissues of Sprague-Dawley rats — A.F. Gualtieri, N. Bursi Gandolfi, et al. (2017)

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