Combined effect of asbestos exposure and tobacco smoking on Finnish anthophyllite miners and millers

Our plain-English summary of Combined effect of asbestos exposure and tobacco smoking on Finnish anthophyllite miners and millers, by L.O. Meurman, R. Kiviluoto, M. Hakama (Annals of the New York Academy of Sciences, 1979).

The study

• Authors: L.O. Meurman, R. Kiviluoto, M. Hakama
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:491-5
• Cited by: 18 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001038).

Summary of the article

This study examined how asbestos exposure and tobacco smoking combine to affect lung cancer risk among workers at two Finnish anthophyllite asbestos quarries. It updated a 1974 report that lacked direct smoking data on deceased workers. The cohort included all workers employed for 3 months or longer between 1936 and July 1, 1967, a total of 1092. Of these, 1045 were followed until September 1, 1977. In 1967, smoking habits were obtained by interview from 793 employees. Causes of death came from death certificates, hospital records and histologic findings, and were based on autopsy in 80 cases. Expected deaths were derived from Finnish proportional mortality statistics and adjusted for heavier smoking among the asbestos workers.

There were 384 deaths. All 44 lung cancer deaths occurred among males, significantly more than expected. The relative risk rose from 1.7 for deaths before July 1967 to 2.4 for later deaths. In 1967-77, the relative risk of lung cancer was 3.3 among heavily exposed workers and 1.4 with low to moderate exposure. Assuming multiplicative effects, the relative risks were 1 for nonsmokers not exposed to asbestos, 1.6 for nonsmoking asbestos workers, 12 for smokers not exposed to asbestos, and 19 for asbestos workers who smoked. Only one nonsmoking asbestos worker had lung cancer. Of 42 asbestosis cases, seven occurred among nonsmokers. Asbestosis was present in 22 of 28 heavily exposed lung cancer deaths.

The authors found a dose-response relationship and results compatible with both multiplicative and promoter models. They concluded that preventive measures are needed.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This study updated the authors' 1974 report on people who worked at least 3 months between 1936 and 1967 for a company with two anthophyllite asbestos quarries in Finland. The asbestos was ground in a hammer mill. Of 1,092 employees, 1,045 were followed until September 1977, and 384 had died. All 44 lung cancer deaths were in men, significantly more than the 22.4 expected. The relative risk of lung cancer was 3.3 with heavy exposure and 1.4 with low to moderate exposure. The authors called this a fairly clear-cut dose-response relationship. They assumed risks multiply and that the smoking habits of workers alive in 1967 represented everyone. On that basis they estimated relative risks, against unexposed nonsmokers, of 1.6 for nonsmoking asbestos workers, 12 for smokers not exposed to asbestos, and 19 for smoking asbestos workers. Among men who died in 1967-77, one of 23 lung cancer deaths was in a nonsmoker. Of 42 asbestosis cases among male workers, 7 were in nonsmokers. The authors concluded that their results fit both the multiplicative and the promotor models.

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: Follow-up (cohort) mortality study of a company's workforce, updating a 1974 report. It focuses on deaths in 1967-77, for which smoking habits were known from 1967 interviews.
• Who was studied: 1,092 people employed for 3 months or longer between January 1, 1936 and July 1, 1967 by a company working two anthophyllite asbestos quarries in Finland. Of these, 1,045 were followed until September 1, 1977 and 47 could not be followed. There were 248 deaths in 1936-67 and 136 in 1967-77 (384 in all). Smoking habits were obtained by interview in 1967 from 793 employees.
• Exposure: Anthophyllite asbestos dust from quarrying and hammer milling, classed as severe or low to moderate. Tobacco smoking was also studied, classed as smoker or nonsmoker.
• Main results:
  • All 44 lung cancer deaths occurred among male employees.
  • The 44 lung cancer deaths were significantly more than the number expected (22.4).
  • The relative risk of lung cancer was 1.7 for workers who died before July 1, 1967 and 2.4 for those who died after that date.
  • Heavily exposed employees had 70 deaths in 1967-77, 17 of them from lung cancer. Their relative risk of 3.3 was significantly different from the expected 1.0.
  • Compared with controls, the relative risk of lung cancer was 3.3 with severe exposure and 1.4 with low to moderate exposure.
  • The authors described the difference between severe and low-to-moderate exposure as a fairly clear-cut dose-response relationship.
  • Under a multiplicative model, and assuming that the smoking habits of those alive in 1967 represented all employees, the estimated relative risk for a nonsmoking asbestos worker was 1.6. The comparison group was nonsmokers not exposed to asbestos (relative risk 1). The 1974 report had estimated 1.4.
  • Under the same model and assumptions, the estimated relative risk was 12 for smokers not exposed to asbestos and 19 for asbestos workers who smoked.
  • Among male asbestos workers who died in 1967-77, smokers had 95 deaths, 22 of them from lung cancer. Nonsmokers had 24 deaths, one of them from lung cancer.
  • Separately, the article counted 42 cases of asbestosis among male asbestos workers by smoking habit, 7 of them in nonsmokers. The article does not say that all 42 were among the men who died in 1967-77. The authors noted that asbestosis was almost equally frequent among smokers and nonsmokers.
  • Asbestosis was present in 22 of the 28 heavily exposed workers who died of lung cancer. All of those with more than 10 years of exposure also had asbestosis.
  • Among female asbestos workers there were 58 deaths. Fourteen were from asbestosis and none from lung cancer.
• The authors' conclusion: The authors concluded that their results were compatible with both the multiplicative and the promotor models of how asbestos and smoking combine. They also concluded that the strong association between lung cancer and smoking combined with asbestos exposure showed a need for preventive measures.
• Limitations the authors state:
  • The authors could not obtain direct information on the smoking habits of workers who had died, a weak point of the earlier study.
  • Smoking habits were known individually only for workers alive on July 1, 1967.
  • The combined relative risk estimates depend on two assumptions: that the smoking habits of those alive in 1967 represented all employees, and that the risks from smoking and asbestos multiply.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Anthophyllite, Lung Cancer, Habit, Death Certificate, Autopsy, Proportional mortality, Relative Risk.

Related studies

• Four cases of mesothelioma among Finnish anthophyllite miners — A. Karjalainen, L.O. Meurman, et al. (1994)
• Asbestos exposure, cigarette smoking, and airflow limitation in long-term Canadian chrysotile miners and millers — R. Bégin, R. Boileau, et al. (1987)
• Incidence of cancer among anthophyllite asbestos miners in Finland — L.O. Meurman, E. Pukkala, et al. (1994)
• Mortality in Canadian miners and millers exposed to chrysotile — J.C. McDonald, F.D. Liddell (1979)
• The combination of effects on lung cancer of cigarette smoking and exposure in quebec chrysotile miners and millers — F.D. Liddell, B.G. Armstrong (2002)
• Long-term mortality experience of chrysotile miners and millers in Thetford Mines, Quebec — W.J. Nicholson, I.J. Selikoff, et al. (1979)

Browse more research in Annals of the New York Academy of Sciences, or return to medical research.