Some Observations of the Dust Content and Composition in Lungs with Asbestosis in Coal Miners

Our plain-English summary of Some Observations of the Dust Content and Composition in Lungs with Asbestosis in Coal Miners, by G. Nagelschmidt.

The study

• Author: G. Nagelschmidt
• Published: Annals of the New York Academy of Sciences
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This paper, from the Safety in Mines Research Establishment in Sheffield, England, reported preliminary analyses of the mineral dust left in lungs of people with asbestosis. It first reviewed earlier studies by others. Between about 20 and 25 lungs from Great Britain were studied, from workers who may have been exposed to chrysotile, amosite and crocidolite. They were ashed, treated with acid and examined by microscopy and X-ray diffraction. In over half of them, whatever the grade of fibrosis, no more than traces of asbestos were found. The fibers that were found were probably amosite, and chrysotile was not positively identified. Dust amounts rose slightly with grade of fibrosis, but the difference between the moderate and severe groups was not significant. Of 22 lungs from South African workers exposed to amosite or crocidolite, fibers were seen mainly in the amosite lungs. The author called the asbestos estimates inexact and the South African data incomplete. The author concluded that the most likely explanation for the missing asbestos was that it dissolves in the lungs.

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: Preliminary laboratory analysis of the dust content and composition of lungs from people with asbestosis, preceded by a review of earlier studies by other researchers
• Who was studied: Lungs from asbestosis cases in Great Britain (about 20 to 25 lungs, supplied by the London Pneumoconiosis Medical Panel and the Pneumoconiosis Research Unit, Cardiff), graded minimal, moderate or severe by pathologists. Also 22 lungs from South Africa (8 amosite, 14 crocidolite; 8 minimal, 11 moderate, 3 severe fibrosis)
• Exposure: Workers in Great Britain had mixed exposures, possibly to chrysotile, amosite and crocidolite. The South African men worked in specific mines and were exposed to either amosite or crocidolite
• Main results:
  • In the lungs from Great Britain, more than half showed no more than traces of asbestos, whatever the grade of fibrosis
  • In the lungs from Great Britain, the asbestos found was judged to be amosite rather than crocidolite. No positive identification of chrysotile was made in any residue
  • In the lungs from Great Britain, where fibers were found, their amount may have been of the order of 0.1 to 0.3 per cent of dried lung, or less than one gram in both lungs
  • In the lungs from Great Britain, the amount of mineral dust rose slightly with increasing grade of fibrosis
  • In the lungs from Great Britain, the difference in dust amount between the moderate and severe fibrosis groups was not significant
  • The asbestos workers' lungs from Great Britain (20 lungs) averaged 0.43 per cent iron oxide (Fe2O3) of dried lung and 4.2 grams of total dust in both lungs. Coal miners with X-ray category 1 (26 lungs) averaged 0.45 per cent and 20 grams. The asbestos lungs thus had about as much iron as these coal miners' lungs but far less dust
  • In the South African lungs, residues averaged 2 per cent of dried lung. Neither type of asbestos nor grade of fibrosis showed a clear relationship to the amount of residue
  • In the South African lungs, fiber frequencies were not related to grade of fibrosis
  • In the South African lungs, fiber frequency varied with type of asbestos. Of the crocidolite-exposed lungs, 13 showed trace or no fibers, 1 showed some and 0 showed much. Of the amosite-exposed lungs, 0 showed trace or none, 4 showed some and 4 showed much
• The authors' conclusion: The authors concluded that in over half the lungs from Great Britain and South Africa practically no asbestos was found, whatever the grade of fibrosis. They considered this unlikely to be due to faulty technique, and the most likely explanation to be that asbestos dissolves in the lungs. Finding only amosite in some residues agreed with their reasoning that amosite is the most resistant type. They said further research was required
• Limitations the authors state:
  • The author stated that the work had not yet led to any definite conclusions
  • Analytical data and information on the South African lungs were incomplete at the time of writing
  • The asbestos estimates were too inexact to support definite conclusions about links with exposure and survival periods
  • The acid treatment used on the British lungs removed part of any chrysotile present
  • Further study of methods for recovering asbestos from lungs, especially chrysotile, was required
  • No X-ray diffraction diagrams were obtained for the South African residues

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile, Amosite, Crocidolite, X-Ray Diffraction (XRD), Fibrosis.

Browse return to medical research.