Some observations of the dust content and composition in lungs with asbestosis, made during work on coal miners pneumoconiosis

Our plain-English summary of Some observations of the dust content and composition in lungs with asbestosis, made during work on coal miners pneumoconiosis, by G. Nagelschmidt (Annals of the New York Academy of Sciences, 1965).

The study

• Author: G. Nagelschmidt
• Journal: Annals of the New York Academy of Sciences
• Published: 1965;132(1):64-76
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy.

In plain English

This paper, from Britain's Safety in Mines Research Establishment, reported laboratory analyses of the mineral dust left in the lungs of people with asbestosis. It also began with a review of earlier studies. The author examined 25 lungs from British asbestos workers, graded minimal, moderate or severe by pathologists. The author also examined 22 lung residues from South African workers exposed to amosite or crocidolite in specific mines. In over half the British lungs, whatever the grade of fibrosis, no more than traces of asbestos were found. Where fibers were seen, they were probably amosite, and chrysotile was not positively identified in any residue. Dust amounts rose only slightly with grade of fibrosis, and the moderate-severe difference was not significant. Iron levels were well above the roughly 0.1 per cent of dried lung described for unexposed lungs. In South Africa, over half of the 22 residues showed only traces of fibers (13 in the paper's table, 14 in its text), unrelated to grade of fibrosis. The author concluded that asbestos most likely dissolves in the lungs. The author noted that the South African data were incomplete and that chrysotile recovery methods needed further study.

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: Laboratory analysis of mineral dust isolated from lungs of people with asbestosis (a descriptive series of lungs), preceded by a short review of earlier lung-dust studies
• Who was studied: Lungs from British asbestos workers with asbestosis, graded minimal, moderate or severe by pathologists (the text describes some 20 cases; the detailed table lists 25 lungs). Also 22 lung residues from South African workers with asbestosis.
• Exposure: British workers usually had mixed exposure to chrysotile, amosite and crocidolite. The South African men worked only in specific mines, with exposure grouped as amosite or crocidolite.
• Main results:
  • British lungs: the amount of mineral dust rose slightly with grade of fibrosis. The difference between the moderate and severe groups was not significant, and as per cent of dried lung there was hardly any difference.
  • British lungs: in over half the lungs, irrespective of grade of fibrosis, no more than traces of asbestos were found.
  • British lungs: the author assumed that the 11 residues with more than traces of asbestos each contained 10 per cent asbestos. On that assumption, the average asbestos content was estimated at 0.17 per cent of dried lung (range 0.06 to 0.34 per cent), or less than 0.5 gm in both lungs. The author described this as likely an overestimate.
  • British lungs: the asbestos found was judged to be amosite rather than crocidolite. Chrysotile could not be positively identified in any residue.
  • British lungs: iron content was well above the level for lungs of people not exposed to dust (of the order of 0.1 per cent of dried lung). The lungs had about as much iron as coal miners' lungs in X-ray category 1 but far less dust. The author suggested that much of the iron may have come from debris of asbestos bodies.
  • British lungs: the author saw a possible slight tendency for high asbestos and silica values to go with shorter survival after exposure ended. The scatter was too large for definite conclusions.
  • 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.
  • South African lungs: of 22 residues, four were scored as containing 'much' asbestos and five 'some'. The rest, over half, showed only traces of fibers. The text gives 14 such residues, which would make 23 in all. The fiber-estimate table gives 13, which makes 22. Fiber frequency was not related to grade of fibrosis but was related markedly to type of asbestos. The larger fibers could have been amosite.
• The authors' conclusion: The author concluded that in over half the lungs from both countries practically no asbestos was found, irrespective of grade of fibrosis. The author judged this unlikely to be a technical fault and considered that the most likely explanation is that asbestos dissolves in the lungs. Chrysotile was expected to be attacked most easily and amosite to be most resistant.
• Limitations the authors state:
  • 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 percentages assigned to the 'much', 'some' and 'nil or trace' asbestos scores were rough guesses.
  • The acid treatment used on the British lungs removed 30 per cent of chrysotile in tests.
  • The acetic acid method used on the South African lungs decomposed chrysotile in tests.
  • No X-ray diffraction was done on the South African residues.
  • The figures for minimal fibrosis in the silica and iron analyses were based on three lungs only.
  • Further study of the technique of recovering asbestos, especially chrysotile, from lungs is required.

Topics

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

Medical terms in this study, explained in our Lexicon: Pneumoconiosis.

Related studies

• Ventilatory function after exposure to various respirable hazards in a population of former coal miners — G.M. Calvert, M. Moore, et al. (1991)
• Some investigations into the nature and cause of massive fibrosis (MF) in the lungs of South African gold, coal, and asbestos mine workers — M.C. Leibowitz, B. Goldstein (1987)
• Investigative techniques in the laboratory study of coal workers' pneumoconiosis: recent advances at the cellular level — J.S. Harington (1972)
• Molecular basis for differences in susceptibility to coal workers' pneumoconiosis — P.J. Borm, R. Schins, et al. (1992)
• Experimental infective pneumoconiosis: effect of asbestos dust and Candida albicans infection on the lungs of rhesus monkeys — S.H. Zaidi, R. Shanker, et al. (1973)
• WHO/ILO work-related burden of disease and injury: Protocol for systematic reviews of occupational exposure to dusts and/or fibres and of the effect of occupational exposure to dusts and/or fibres on pneumoconiosis — D. Mandrioli, V. Schlünssen, et al. (2018)

Browse more research in Annals of the New York Academy of Sciences, or return to medical research.