Occupational Chest Diseases in Gold Miners

Our plain-English summary of Occupational Chest Diseases in Gold Miners, by G.W.H. Schepers (1955).

The study

• Author: G.W.H. Schepers
• Published: Archives of Industrial Health, Volume 12. July 1955
• 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 article reviewed the history of occupational chest diseases in South African gold mines from official reports, with statistical trends over the past 40 years. It covered silicosis, tuberculosis and "pulmonary disability", compensable under a 1952 law; it did not discuss asbestos. The author described an early fall in recorded silicosis, then a sharp rise in certifications in the early 1950s. In 1953-1954, more than 770 second-stage and more than 400 third-stage silicotics were found among more than 30,000 white miners. The author traced the rise to new diagnostic criteria applied by the Bureau, not changed legal criteria. The author wrote that clinical and autopsy experience favored earlier over-strictness, rather than recent leniency, as the explanation. For the workers the article calls Negro laborers, the author related about 2000 new tuberculosis cases to the whole workforce of about 300,000. The author called the resulting rate 10 times that among South Africa's white population. The author concluded that too much harmful dust was still being breathed. The author noted that less than 2% of these laborers were screened by the Bureau and that accurate dust-exposure statistics were lacking.

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: Historical and statistical review of official reports and records
• Who was studied: White miners and the workers the article calls 'Negro laborers' in the gold mines of the Union of South Africa (mainly the Witwatersrand). The history runs from the start of gold mining to 1955, and the statistical trends cover the past 40 years. In 1953-1954 the white workforce exceeded 30,000. About 300,000 laborers worked in the scheduled gold mines.
• Exposure: Mine dust in gold mining, studied for silicosis, tuberculosis and pulmonary disability. No asbestos or asbestos fibers are discussed. The author noted that white miners spend more years in the mines, while the laborers are probably more directly in contact with dust because they do the drilling and shoveling.
• Main results:
  • Among white miners in 1953-1954, more than 770 second-stage and more than 400 third-stage silicotics were discovered. The workforce they came from exceeded 30,000. By comparison, 789 cases were certified among 15,000 miners in 1917.
  • The author stated that the legal criteria for silicosis and tuberculosis had not been altered since 1946. The author traced the rise in certifications to the Bureau applying new diagnostic criteria in interpreting the existing definitions.
  • The author weighed two explanations: either the Bureau had recently become too lenient, or it had previously been too strict. The author wrote that clinical and autopsy experience tended to favor the second.
  • For the rapid rate at which silicotics were reclassified to higher stages, the author viewed the rise as a belated correction of earlier retarded certification.
  • Pulmonary disability was recognized in the Silicosis Act as an independent new compensable entity. The relevant law came into effect only in 1952.
  • When silicosis advanced beyond the first stage, it did so relatively rapidly. In the 1921, 1931 and 1941 cohorts, the majority of cases had advanced within 10 years of first discovery.
  • Of the 1937 group of new silicotics, fewer than 20% had died from silicosis within the following 15 years of follow-up.
  • Among the laborers in 1953-1954, the Bureau found more than 1100 new cases of tuberculosis and more than 850 new cases of tuberculosis combined with silicosis, among less than 2% of the workforce. The author related these approximately 2000 cases to the whole 300,000 workers. The author described the resulting new case rate as 10 times the tuberculosis attack rate among the white population of South Africa.
• The authors' conclusion: The author concluded that too much harmful dust was still being breathed by the miners. The author also judged that the official 'ideal' dust level was not yet satisfactory.
• Limitations the authors state:
  • For the laborers, not all were examined by x-ray and less than 2% were screened by the Bureau itself.
  • No accurate statistics were available on the average dust exposures of the laborers.
  • The figures reflect only the scheduled gold mines; the impact on other mines was not known.

Topics

Medical terms in this study, explained in our Lexicon: Silicosis, Autopsy.

Browse return to medical research.