Periodic examination of asbestos and coal miners

Our plain-English summary of Periodic examination of asbestos and coal miners, by G.K. Sluis-Cremer (Annals of the New York Academy of Sciences, 1979).

The study

• Author: G.K. Sluis-Cremer
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:541-3
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 003988).

In plain English

This is the text of a talk by the author, from South Africa's Medical Bureau for Occupational Diseases, on how the country monitored miners at risk of asbestos-related disease. By law, miners were examined before employment and annually or more often while working. When a person died whose treating doctor had reason to believe they had ever worked on a mine, the doctor had to send the heart and lungs for examination. For those not yet compensated, this required the family's agreement. The author compared postmortem reports from January 1, 1974 to January 1, 1978 for black asbestos and coal miners. Active tuberculosis was slightly more common in the asbestos miners, but not much more so. Of asbestos miners with active tuberculosis, 17 of 22 died of it, compared with 37 of 93 coal miners. The author called this difference highly significant. Among workers who did not die violent or sudden deaths, pneumonia was a direct or contributing cause of death in 45% of asbestos miners and 32% of coal miners (p = .01). The author noted that data on former workers were poor. The type of asbestos was not stated.

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: Conference talk describing South Africa's legal surveillance system for miners, with a comparison of statutory postmortem lung examination reports for asbestos miners and coal miners
• Who was studied: Black asbestos miners (247 with postmortem reports: 61 aged 17-29, 126 aged 30-49, 60 aged 50 and over) and black coal miners (354, 662 and 235 in the same age groups) in South Africa whose lungs were examined after death, January 1, 1974 to January 1, 1978
• Exposure: Work at South African asbestos mines (fiber type not stated), compared with work at coal mines, which the author chose because recruiting and medical services were similar
• Main results:
  • South African law required pre-employment examinations and annual or more frequent periodic examinations of all working miners. The periodic examination included a physical examination and a mandatory x-ray, and lung function tests were slowly being introduced.
  • When a person died and the doctor who cared for them in their final illness had reason to believe they had ever worked on a mine, that doctor had a duty to send the heart and lungs for examination.
  • Postmortem examination of the heart and lungs was a statutory requirement for those not yet compensated, provided the family agreed.
  • Active tuberculosis at postmortem was found in 2/61 (3.3%), 11/126 (8.8%) and 9/60 (15%) of asbestos miners aged 17-29, 30-49 and 50 and over, and in 22/354 (6.2%), 47/662 (7.1%) and 24/235 (10.2%) of coal miners. The author described tuberculosis as slightly, but not much, more prevalent in asbestos miners.
  • Among miners with active tuberculosis, it was the cause of death in 17 of 22 asbestos miners and in 37 of 93 coal miners. The author described the difference as highly significant.
  • Among miners who did not die violent or sudden deaths, lobar or bronchopneumonia was a direct or contributing cause of death in 54/119 (45%) of asbestos miners and 156/494 (32%) of coal miners, a significant excess for the asbestos miners (p = .01)
• The authors' conclusion: The author suspected that black asbestos miners did not get more tuberculosis but fared much worse when they did, and felt this had treatment implications. The author regarded the tuberculosis and pneumonia findings as two things that could be acted upon.
• Limitations the authors state:
  • Data covered mainly currently working miners. Former workers were seen only if they chose to come for examination, so there was little follow-up.
  • Data on causes of death were poor. The rates of bronchial cancer and mesothelioma in former asbestos mine workers were not known.

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)
• A battle for compensation for Welsh coal miners: JS Haldane v "Sericite" Jones, 1932-1934 — M. Greenberg (1997)
• Progression of irregular opacities in asbestos miners — G.K. Sluis-Cremer, E. Hnizdo (1989)
• Some observations of the dust content and composition in lungs with asbestosis, made during work on coal miners pneumoconiosis — G. Nagelschmidt (1965)
• Asbestosis in South African asbestos miners — G.K. Sluis-Cremer (1970)
• Respiratory symptoms and functional status in workers exposed to silica, asbestos, and coal mine dusts — X.R. Wang, D.C. Christiani (2000)

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