Mesothelioma and lung tumors attributable to asbestos among petroleum workers

Our plain-English summary of Mesothelioma and lung tumors attributable to asbestos among petroleum workers, by V. Gennaro, M.M. Finkelstein, M. Ceppi, et al (American Journal of Industrial Medicine, 2000).

The study

• Authors: V. Gennaro, M.M. Finkelstein, M. Ceppi, V. Fontana, F. Montanaro, A. Perrotta, R. Puntoni, S. Silvano
• Journal: American Journal of Industrial Medicine
• Published: 2000;37(3):275-82
• Cited by: 33 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Asbestos exposure has been definitively found to be associated with both mesothelioma and lung cancer. Nevertheless, in the overall population of oil refinery workers potentially exposed to asbestos, many studies clearly show a definitely increased risk of mesothelioma, but no proven excess of lung cancer after comparison to the general population. Through the presentation of new data and the re-appraisal of two recent and independent epidemiological studies conducted in Liguria, Italy, and Ontario, Canada, we attempt to shed light on this apparently paradoxical finding.

Methods: Lung cancer mortality was studied among maintenance workers exposed to asbestos, and among two other subgroups of refinery employees: blue collar and white collar workers. The comparison with blue collar workers was performed in order to take into account the role of healthy worker effect, smoking habit, and the socioeconomic level. The comparison with white collar workers was performed to control for other occupational lung carcinogens.

Results And Conclusions: Results reveal a consistency between the two studies and show that 96-100% of the mesotheliomas and 42-49% of the lung tumors arising among maintenance workers were attributable to asbestos exposure. Our new analysis, estimating two cases of asbestos-related lung cancer for each case of mesothelioma, confirms published findings on the magnitude of asbestos-related tumors in oil refineries.

Copyright 2000 Wiley-Liss, Inc.

In plain English

This article re-analysed an updated refinery-worker cohort study from Liguria, Italy, and a death-certificate case-control study from Ontario, Canada. It focused on maintenance workers, whose high mesothelioma rates the authors treated as signalling asbestos exposure. In the Italian refinery, where amosite, chrysotile and crocidolite were detected, five pleural mesotheliomas occurred among 357 maintenance workers (SMR 29.27 against the national population; 95% confidence interval 9.51 to 68.31). In Ontario, maintenance workers' mesothelioma odds ratio was 24.5 (90% confidence interval 3.1 to 102.0). The authors attributed 96 to 100% of these mesotheliomas to asbestos. Against white collar workers, Italian maintenance workers had 16 lung cancer deaths (SMR 1.97, 95% confidence interval 1.13 to 3.20). Against other workers, Ontario maintenance workers had 28 (odds ratio 1.73, 90% confidence interval 0.83 to 3.60). The authors attributed 49.2% (Italy; 95% confidence interval 26.4 to 72.4) and 42.2% (Ontario; 10.8 to 82.6) of these lung cancers to asbestos. That gave 1.6 to 2.1 asbestos-related lung cancers per mesothelioma, agreeing with earlier estimates, they said. They noted they lacked direct workplace measurements and smoking data.

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: Re-analysis of two earlier studies: a cohort study of refinery workers in Liguria, Italy (updated with new data) and a death-certificate-based case-control study in Ontario, Canada
• Who was studied: Italy: 932 workers at one Liguria refinery (22% white collar, 38% maintenance workers, 40% other blue collar), including 357 maintenance workers (9,548 person-years). The white collar reference group combined two Italian refineries. Ontario: deaths in the Ontario Mortality Registry from 1980 to 1992, with usable data on 17 men with mesothelioma and 46 controls, and on 424 men with lung cancer and 431 controls.
• Exposure: Asbestos exposure among refinery maintenance workers. In the re-analysed Italian plant, amosite, chrysotile and crocidolite were detected. No direct exposure measurements were available.
• Main results:
  • Italian maintenance workers had 5 pleural mesothelioma deaths. The SMR was 5.47 (95% CI 1.78 to 12.76) against the local population and 29.27 (95% CI 9.51 to 68.31) against the national population.
  • In Ontario, 6 of the 17 men with mesothelioma had been maintenance workers. The mesothelioma odds ratio for maintenance workers was 24.5 (90% CI 3.1 to 102.0).
  • The authors estimated that 96 to 100% of mesotheliomas among maintenance workers in the two studies were attributable to asbestos.
  • Compared with the Italian general population, lung cancer deaths among Italian maintenance workers were not significantly elevated (SMR 1.42; 95% CI 0.81 to 2.30).
  • When all blue collar workers (including maintenance workers) were combined, lung cancer relative risks ranged from 0.92 to 1.47 depending on the comparison group.
  • In internal comparisons, Italian maintenance workers had 16 lung cancer deaths, an SMR of 1.97 (95% CI 1.13 to 3.20) compared with white collar workers. Ontario maintenance workers had 28, an odds ratio of 1.73 (90% CI 0.83 to 3.60) compared with other workers.
  • The estimated share of lung cancers among maintenance workers attributable to asbestos was 42.2% (95% CI 10.8 to 82.6) in Ontario and 49.2% (95% CI 26.4 to 72.4) in the Italian plant.
  • The ratio of asbestos-attributable lung cancer deaths to mesothelioma deaths was 1.6 in Liguria and 2.1 in Ontario.
• The authors' conclusion: The authors concluded that their analysis, which estimated about two asbestos-related lung cancers for each mesothelioma, confirmed published findings on the size of asbestos-related tumor risk in oil refineries.
• Limitations the authors state:
  • The authors had no direct information on workplace exposure measurements (hygienic data) or on the workers' smoking habits.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Exposure, Lung Cancer, Healthy Worker Effect, Habit.

Related studies

• RE: Mesothelioma and lung tumors attributable to asbestos among petroleum workers. Am. J. Ind. Med. 2000. 37:275-282 — E.R. Ludwig, L. Madeksho, et al. (2001)
• RE: Mesothelioma and lung tumors attributable to asbestos among petroleum workers. Am. J. Ind. Med. 2000. 37:275-282 — S.P. Tsai, L.C. Waddell, et al. (2001)
• Asbestos exposure and cancer mortality among petroleum refinery workers: a Poisson regression analysis of updated data — F. Montanaro, M. Ceppi, et al. (2004)
• Lung cancer incidence in Canadian petroleum workers — A.R. Schnatter, M.J. Nicolich, et al. (2012)
• Mortality and cancer morbidity in a cohort of Canadian petroleum workers — R.J. Lewis, A.R. Schnatter, et al. (2003)
• An updated study of mortality among workers at a petroleum manufacturing plant — Y. Honda, E. Delzell, et al. (1995)

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