Risk of lung cancer associated with occupational exposure to mineral wools: updating knowledge from a french population-based case-control study, the ICARE study

Our plain-English summary of Risk of lung cancer associated with occupational exposure to mineral wools: updating knowledge from a french population-based case-control study, the ICARE study, by F. Guida, S. Paget-Bailly, F. Lamkarkach, et al (Journal of Occupational and Environmental Medicine, 2013).

The study

• Authors: F. Guida, S. Paget-Bailly, F. Lamkarkach, O. Gaye, S. Ducamp, G. Menvielle, A. Papadopoulos, M. Matrat, J. Févotte, S. Cénée, D. Cyr, A. Schmaus, M. Carton, L. Radoï, B. Lapôtre-Ledoux, F. Molinié, D. Luce, I. Stücker
• Journal: Journal of Occupational and Environmental Medicine
• Published: 2013;55(7):786-95
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: To assess the risk of lung cancer associated with exposure to mineral wools (MWs), while taking into account smoking, asbestos, and crystalline silica exposures.

Methods: The analyses were restricted to men (1350 cases and 1912 controls). Lifelong occupational history was collected. MWs and asbestos exposures were assessed, using task-exposure matrices and silica exposure, a job-exposure matrix.

Results: We observed consistent not-significant increased risks of lung cancer of the same order of magnitude among workers exposed to high levels of MWs (odds ratio, 1.4; 95% confidence interval: 0.9 to 2.2; for highest quartile of the Cumulative Exposure Index).

Conclusions: These results do not allow to draw firm conclusion about a carcinogenic effect of MWs on the lung, but they cannot exclude it. Given the high number of potentially exposed workers, it will be necessary to replicate them in a future further removed from the asbestos ban.

In plain English

This French population-based case-control study (ICARE, 2001 to 2007) examined whether work with mineral wools (glass, rock and slag wools) was linked to lung cancer. It analysed 1350 men with lung cancer and 1912 men without. Hygienist-built matrices estimated exposure to mineral wools and asbestos from job questionnaires, and a job-exposure matrix estimated crystalline silica. After adjusting for smoking, asbestos and silica, men in the highest quarter of cumulative mineral wool exposure had an odds ratio of 1.40 (95% CI 0.87 to 2.24), which was not statistically significant. Counting only exposure from more than 40 years before interview, the highest third had an odds ratio of 1.9 (95% CI 1.2 to 3.2). With similar adjustment, ever having asbestos exposure carried an odds ratio of 1.46 (95% CI 1.17 to 1.83). The authors found too few men exposed to mineral wools but never to asbestos, and could not rule out leftover confounding. The authors concluded that a cancer-causing effect of mineral wools cannot be excluded, and that the analyses should be repeated further from the asbestos ban.

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: Multicenter, population-based case-control study (the ICARE study)
• Who was studied: Men from 10 French departments with a cancer registry: 1350 incident, histologically confirmed lung cancer cases and 1912 population controls for whom all three exposures could be assessed. Women were excluded because few were exposed to mineral wools.
• Exposure: Lifetime occupational exposure to mineral wools (glass, rock and slag wools) and to asbestos (fiber types not specified), estimated with task-exposure matrices built by three hygienists. Crystalline silica was estimated with a job-exposure matrix. Exposure was scored as ever/never, maximum probability, maximum intensity, duration and a Cumulative Exposure Index.
• Main results:
  • Men in the highest quartile of the mineral wool Cumulative Exposure Index (161 cases, 99 controls): odds ratio 2.57 (1.85 to 3.57) adjusted for smoking and other basic factors; 1.80 (1.17 to 2.76) after adding asbestos; 1.40 (0.87 to 2.24) after adding asbestos and silica.
  • Adjusting for co-exposure to asbestos and silica reduced all tested mineral wool associations, and none remained statistically significant.
  • Men with definite mineral wool exposure for more than 15 years at an intensity of more than 1 fiber/cm3: odds ratio 2.1 (95% CI 0.8 to 5.6).
  • With lag times applied (recent exposure ignored), the highest tertile of mineral wool exposure had odds ratios of 1.5 (95% CI 0.95 to 2.3) at 30 years and 1.9 (95% CI 1.2 to 3.2) at 40 years. There was no association with 10- or 20-year lags.
  • When results were split by level of asbestos exposure, elevated odds ratios for mineral wools appeared only among men with asbestos exposure below the fourth quintile.
  • Ever exposure to asbestos, adjusted for the other two substances: odds ratio 1.46 (95% CI 1.17 to 1.83). The attributable fraction was 24.0% (95% CI 10.8 to 35.3).
  • Ever exposure to crystalline silica: odds ratio 1.4. The attributable fraction was 8.3% (95% CI 4.3 to 12.2).
  • Men ever exposed to all three substances (mineral wools, silica and asbestos) had an odds ratio of around 3.
  • The construction sector accounted for 76% of the industries in which jobs had potential joint exposure to all three substances.
• The authors' conclusion: The authors concluded that their results do not allow a firm conclusion, but that a potential carcinogenic effect of mineral wools on the lung cannot be excluded. They said the analyses should be replicated in a future further removed from the asbestos ban.
• Limitations the authors state:
  • The study could not distinguish rock wool, slag wool and glass wools.
  • Too few workers had been exposed to mineral wools but never to asbestos.
  • The raised odds ratios at the highest mineral wool exposures could be due to residual confounding by asbestos or silica.
  • Retrospective exposure estimates were inevitably misclassified to some degree, which could bias results toward no effect.
  • Recall bias in self-reported job histories cannot be completely excluded.
  • The strict definition of non-exposure left many subjects with missing exposure data for asbestos and mineral wools.

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Occupational Exposure, Case-Control Study, Crystalline, Occupational History, Asbestos Exposure, Odds Ratio, confidence interval.

Related studies

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• Occupational exposure to wood dust and risk of lung cancer: the ICARE study — M. Matrat, L. Radoï, et al. (2019)
• Laryngeal and hypopharyngeal cancer and occupational exposure to asbestos and man-made vitreous fibers: results of a case-control study — J.L. Marchand, D. Luce, et al. (2000)
• Time-dependent effect of intensity of smoking and of occupational exposure to asbestos on the risk of lung cancer: results from the ICARE case-control study — E. Lévêque, A. Lacourt, et al. (2018)
• Investigation of occupational and environmental causes of respiratory cancers (ICARE): a multicenter, population-based case-control study in France — D. Luce, I. Stücker, et al. (2011)

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