Lung cancer and exposure to man-made vitreous fibers: results from a pooled case-control study in Germany

Our plain-English summary of Lung cancer and exposure to man-made vitreous fibers: results from a pooled case-control study in Germany, by H. Pohlabeln, K.H. Jöckel, I. Brüske-Hohlfeld, et al (American Journal of Industrial Medicine, 2000).

The study

• Authors: H. Pohlabeln, K.H. Jöckel, I. Brüske-Hohlfeld, M. Möhner, W. Ahrens, U. Bolm-Audorff, R. Arhelger, W. Römer, L. Kreienbrock, M. Kreuzer, I. Jahn, H.E. Wichmann
• Journal: American Journal of Industrial Medicine
• Published: 2000;37(5):469-77
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: To investigate the association between lung cancer and occupational exposure to man-made vitreous fibers (MMVF), a pooled analysis of two case-control studies was conducted in the years 1988-1994.

Methods: The case series consisted of 3498 males who were histologically or cytologically verified primary lung cancer cases. 3541 male population controls were drawn at random from the general population and matched to cases by sex, age, and place of residence. To examine the relationship between MMVF and lung cancer we asked all study subjects who worked for at least 6 months as construction and installation workers whether they ever installed or removed insulations and what kind of insulation material they used.

Results: Some 304 (8.7%) cases and 170 (4.8%) controls reported to have insulated with glass wool or mineral wool mats. Coded as ever/never exposed, the odds ratio was 1.48 (95% CI: 1.17-1.88), adjusted for smoking and asbestos. To be sure to exclude any confounding effect of asbestos, we tried to identify those cases and controls who insulated with glass wool or mineral wool mats only and never reported any asbestos exposure. For this group we calculated an odds ratio of 1.56 (95% CI: 0.92-2.65), after adjustment for smoking. An elevated risk was also estimated on the basis of an expert rating which was done for a subgroup of cases and controls. Ever exposure to MMVF (but not to asbestos) in this subgroup yielded an odds ratio of 1.30 (95% CI: 0.82-2.07).

Conclusions: Our study provides some indication for an excess risk of man-made vitreous fibers. This result also persists after adjustment for smoking and asbestos.

Copyright 2000 Wiley-Liss, Inc.

In plain English

Two pooled German case-control studies compared 3,498 men with lung cancer and 3,541 population controls. Construction workers were asked about insulation work with glass or mineral wool, and electrical and electronics fitters about glass fibers or mineral wool on wiring, electrical components or switchboards. These man-made vitreous fibers (MMVF) were not distinguished by kind. Construction workers who insulated with glass wool or mineral wool mats (304 cases, 170 controls) had an odds ratio of 1.48 (95% CI 1.17 to 1.88), adjusted for smoking and asbestos. Over 80% of them also reported asbestos exposure. Those reporting no asbestos exposure (51 cases, 28 controls) had a smoking-adjusted odds ratio of 1.56 (95% CI 0.92 to 2.65), not statistically significant. Fitters who used glass fibers or mineral wool for such insulation (55 cases, 52 controls) had an odds ratio of 1.00 (95% CI 0.63 to 1.58), no indication of increased risk. Men rated MMVF-exposed by experts but reporting no asbestos exposure had an odds ratio of 1.30 (95% CI 0.82 to 2.07), with no dose-response by fiber-years. The authors concluded this gave some indication of an excess risk from MMVF.

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: Pooled analysis of two population-based case-control studies (the BIPS Study and the GSF Study)
• Who was studied: Men with histologically or cytologically confirmed lung cancer (3498 cases) and male population controls (3541) in Germany. The BIPS Study ran 1988-1993 in Bremen, Frankfurt/Main and surrounding areas. The GSF Study ran 1990-1996 in several German states, using interviews up to the end of 1994. Women were excluded because only three reported MMVF exposure.
• Exposure: Occupational exposure to man-made vitreous fibers. Construction workers who installed or removed insulation were asked whether they used glass or mineral wool. Electrical and electronics fitters were asked whether they installed or removed glass fibers or mineral wool on wiring, electrical components or switchboards. Glass, rock and slag wool were not distinguished. Exposure was measured as lifetime days of exposure and, for a subgroup, as expert-estimated MMVF fiber-years. Asbestos exposure was treated as a confounder.
• Main results:
  • Construction workers who ever insulated with glass wool or mineral wool mats (304 cases, 170 controls) had an odds ratio of 1.48 (95% CI 1.17 to 1.88), adjusted for smoking and asbestos.
  • Among these construction workers, the odds ratio rose with lifetime days of exposure. The highest estimate was for more than 2500 days: 2.61 (95% CI 1.18 to 5.76), adjusted for smoking and asbestos.
  • More than 80% of the MMVF-exposed construction workers also reported asbestos exposure.
  • Construction workers who insulated with glass or mineral wool mats but reported no asbestos exposure (51 cases, 28 controls) had a smoking-adjusted odds ratio of 1.56 (95% CI 0.92 to 2.65).
  • For comparison, ever insulating with asbestos products gave a smoking-adjusted odds ratio of 1.87 (95% CI 1.44 to 2.43). Other sources of asbestos exposure gave 1.35 (95% CI 1.17 to 1.54).
  • Electrical and electronics fitters who used glass fibers or mineral wool for insulation on wiring, electrical components or switchboards (55 cases, 52 controls) had an odds ratio of 1.00 (95% CI 0.63 to 1.58), adjusted for smoking and asbestos. This compared them with fitters who were not exposed, and the authors found no indication of an elevated risk in this exposed group.
  • In the expert rating, 172 of 453 rated cases and 120 of 420 rated controls were classed as ever exposed to MMVF. The odds ratio was 1.22 (95% CI 0.92 to 1.61), adjusted for smoking and asbestos.
  • Subjects rated as MMVF-exposed by the experts who reported no asbestos exposure (59 cases, 39 controls) had a smoking-adjusted odds ratio of 1.30 (95% CI 0.82 to 2.07).
  • In that expert-rated group there was no dose-response. The odds ratio was 1.41 (95% CI 0.73 to 2.72) below the median of 0.42 fiber-years and 1.20 (95% CI 0.63 to 2.30) at or above it.
  • Adjusting additionally for social class lowered the asbestos-free construction-worker odds ratio from 1.56 to 1.38 (95% CI 0.81 to 2.36). It lowered the expert-rated figure from 1.30 to 1.20 (95% CI 0.75 to 1.92).
• The authors' conclusion: The authors concluded that, although no dose-response relationship with MMVF fiber-years was found, the study should be taken as a serious indication of a possible lung cancer risk from MMVF. They also stated that the result persisted after adjustment for smoking and asbestos.
• Limitations the authors state:
  • Low response among controls in the GSF Study (41%) means selection bias cannot be completely ruled out.
  • The different kinds of MMVF (glass, rock, slag wool) could not be distinguished.
  • Small numbers meant the risk estimate for MMVF-exposed workers without asbestos exposure was no longer statistically significant.
  • The lack of a dose-response relationship may be interpreted as an argument against causality.
  • Construction workers who insulated with glass or mineral wool probably had other occupational exposures as well. The authors adjusted for these, which had little effect.
  • The expert rating could not be done for the whole study group and was limited to a subgroup.

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, Vitreous, Case-Control Study, Occupational Exposure, Meta-Analysis, Odds Ratio, Confounding, Asbestos Exposure.

Related studies

• Occupational lung cancer risk for men in Germany: results from a pooled case-control study — I. Brüske-Hohlfeld, M. Möhner, et al. (2000)
• Occupational risk factors for lung cancer in women: results of a case-control study in Germany — I. Jahn, W. Ahrens, et al. (1999)
• Risk of mesothelioma and occupational exposure to asbestos and man-made vitreous fibers: evidence from two case-control studies in Montreal, Canada — J. Pintos, M.E. Parent, et al. (2009)
• Lung cancer risk and welding: results from a case-control study in Germany — K.H. Jöckel, W. Ahrens, et al. (1998)
• Occupational exposure to asbestos and man-made vitreous fibers, and risk of lung cancer: evidence from two case-control studies in Montreal, Canada — J. Pintos, M.E. Parent, et al. (2008)
• Cytotoxic and oxidative effects induced by man-made vitreous fibers (MMVFs) in a human mesothelial cell line — D. Cavallo, A. Campopiano, et al. (2004)

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