Rheumatic complaints and pulmonary response to chrysotile dust inhalation in the mines and mills of Quebec

Our plain-English summary of Rheumatic complaints and pulmonary response to chrysotile dust inhalation in the mines and mills of Quebec, by F.M. White, J. Swift, M.R. Becklake (Canadian Medical Association Journal, 1974).

The study

• Authors: F.M. White, J. Swift, M.R. Becklake
• Journal: Canadian Medical Association Journal
• Published: 1974;111(6):533-5
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001291).

Abstract

In 1967-68 an age-stratified random sample of 1069 current workers in Quebec asbestos mines and mills was surveyed. Questions concerning rheumatic complaints were included in a modified MRC questionnaire used at that time, and on this basis a rheumatic severity gradient was devised. No relationship could be detected between rheumatic complaints and pulmonary radiologic response to chrysotile dust exposure, despite implications in the literature that such a relationship might exist.

In plain English

The authors asked whether workers reporting rheumatic complaints showed a different lung response to chrysotile asbestos dust. In 1967-68 an age-stratified random sample of current workers in Quebec asbestos mines and mills was surveyed. Of 1268 men selected, 1069 (84%) took part and 1048 were analysed. From questionnaire answers about stiffness or aching on waking, the men were placed in four rheumatic severity categories. Exposure was measured as accumulated dust exposure across all jobs, and lung response was graded from chest X-rays. Age, dust exposure and X-ray abnormalities showed no obvious differences between the four groups. An analysis taking age and dust into account found no significant differences between the rheumatic categories. The authors concluded that no relationship could be detected between rheumatic complaints and X-ray lung response to chrysotile dust. They noted that their rheumatic measure could not be checked against any objective measurement of arthritis, and that this crude measure carried a high risk of missing a true association.

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: Survey of an age-stratified random sample of current workers, using a questionnaire and chest X-rays, analysed by analysis of covariance
• Who was studied: Current workers (men) in Quebec asbestos mines and mills, surveyed in 1967-68. Of 1268 men selected, 1069 (84%) attended the interview and lung function tests and 1048 were analysed. Eighteen were excluded because they joined after November 1966 and had no recorded X-rays, and three because their work histories were inadequate.
• Exposure: Chrysotile asbestos dust, measured as accumulated dust exposure: the sum of exposure time multiplied by dust concentration for all jobs a man had worked
• Main results:
  • Age, dust index and X-ray (radiologic) abnormalities showed no obvious differences between the four rheumatic severity categories
  • In the analysis of covariance of X-ray category on age and dust, the test for a common slope across rheumatic categories was not significant (0.691, NS)
  • The test for a single common regression plane for all four rheumatic categories found no significant differences (1.446, NS)
  • Reported joint pain, joint swelling and difficulty moving body or limbs were related to the rheumatic severity category
  • A history of arthritis or rheumatism was not related to the rheumatic severity category
• The authors' conclusion: The authors concluded that no relationship could be detected between rheumatic complaints and pulmonary radiologic (chest X-ray) response to chrysotile dust exposure. They added that an association with a more specific form of rheumatic complaint remained open to investigation.
• Limitations the authors state:
  • The rheumatic severity gradient could not be validated because there was no objective measurement of arthritis or rheumatism
  • Using a crude measure of general rheumatic symptoms might dilute an association that exists specifically with rheumatoid arthritis
  • The authors stated there was a high risk of failing to detect a possible true underlying association
  • The chosen severity gradient may not be optimal from the analytic viewpoint

Topics

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

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

Related studies

• The health of chrysotile asbestos mine and mill workers of Quebec — J.C. McDonald, M.R. Becklake, et al. (1974)
• Mortality in the chrysotile asbestos mines and mills of Quebec — J.C. McDonald, A.D. McDonald, et al. (1971)
• Lung function profiles in the chrysotile asbestos mines and mills of Quebec — M.R. Becklake, G. Fournier-Massey, et al. (1976)
• Relationships between simultaneous airborne dust samples taken with five types of instruments at South African asbestos mines and mills — R.S. Du Toit, L.W. Isserow, et al. (1983)
• Temporal patterns of exposure and nonmalignant pulmonary abnormality in Quebec chrysotile workers — R. Copes, D. Thomas, et al. (1985)
• A comparison of the results from intra-pleural and intra-peritoneal studies with those from inhalation and intratracheal tests for the assessment of pulmonary responses to inhalable dusts and fibres — G. Drummond, R. Bevan, et al. (2016)

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