Analysis of the exposure-response relationship for mesothelioma among asbestos-cement factory workers

Our plain-English summary of Analysis of the exposure-response relationship for mesothelioma among asbestos-cement factory workers, by M.M. Finkelstein (Annals of the New York Academy of Sciences, 1991).

The study

• Author: M.M. Finkelstein
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:85-9
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This study tested the cubic residence-time model of mesothelioma risk. The model predicts that each brief exposure raises later incidence in proportion to its intensity and duration and to the cube of time since it occurred. The author used a nested case-control design within a cohort of some 4,900 people employed at an Ontario asbestos-cement factory using chrysotile, crocidolite and amosite. The analysis covered 45 men with mesothelioma (31 pleural, 14 peritoneal), none employed as maintenance workers. Each was matched with 5 controls born in the same year who survived the case. The earliest death came 13 years after first exposure, the most recent 41 years after hire. Effects of time since first exposure and of exposure duration closely matched the model's predictions. Risk rose less than linearly with exposure level. This estimate was preliminary, partly because some men working outside production areas were assigned zero exposure. Age at first exposure showed no effect. Smoking, known for half the men, showed no association with risk. The author concluded that the model fit three industrial cohorts well and could support rough risk estimates for nonindustrial settings.

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: Nested case-control analysis within a cohort, using conditional logistic regression to test the cubic residence-time model
• Who was studied: 45 men with mesothelioma (31 pleural, 14 peritoneal) who had not been maintenance workers, from a cohort of some 4,900 people employed at an Ontario asbestos-cement factory (opened 1948). Each case was matched with 5 controls born in the same year who survived the case. Fifty mesothelioma cases had been identified in the whole cohort.
• Exposure: Work at an asbestos-cement factory. Asbestos-cement pipe was made with silica and chrysotile and crocidolite asbestos. Asbestos-cement board, made with chrysotile only, began in 1955. Amosite insulation materials were introduced in 1960. Asbestos use stopped in 1980. Exposure was measured as average fiber level (cumulative exposure divided by duration), duration of exposure, and time since first exposure.
• Main results:
  • Among the 45 men with mesothelioma, the earliest death occurred 13 years after first exposure and the most recent 41 years after hire.
  • The ages at death of the men with mesothelioma were notably young.
  • For the Ontario asbestos-cement workers, the effects of latency (time since first exposure) and duration of exposure agreed closely with the model's predictions.
  • Observed regression coefficients for the asbestos-cement factory were 0.4 for exposure level (marked as a preliminary estimate), 1.3 for duration and 3.5 for time since first exposure, against model predictions of 1 for level, 1 for duration and 3 for time. The final coefficient was -3.9 against a predicted -1.5. The Australian crocidolite miner values in the same table (0.2, 1.1, 2.8, -7.7) come from de Klerk et al., not from this study.
  • In both the Ontario study and the Australian study, the estimated relationship between exposure level and mesothelioma risk was less than linear.
  • Among the Ontario cases and controls, age at first exposure (under 26 years vs 26 years or more) had no effect on mesothelioma risk.
  • Within the limitations of the available data, there was no association between smoking habit and mesothelioma risk.
• The authors' conclusion: The author concluded that the cubic residence-time model provides a good fit to the mesothelioma pattern of three industrial cohorts and should provide a reasonable basis for risk prediction. The author also concluded that it could be used to give 'order of magnitude' assessments of mesothelioma risk in nonindustrial settings.
• Limitations the authors state:
  • The exposure-level result for the Ontario study is a preliminary estimate, because the exposures of some study subjects need further investigation.
  • Several men employed outside the asbestos production areas developed mesothelioma and were nominally assigned zero exposure, which will influence the risk estimates by exposure level.
  • Smoking histories were available for only half of the men in the case-control analysis.

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-Cement.

Related studies

• Mortality experience of amosite asbestos factory workers: dose-response relationships 5 to 40 years after onset of short-term work exposure — H. Seidman, I.J. Selikoff, et al. (1986)
• Mortality among employees of an Ontario asbestos-cement factory — M.M. Finkelstein (1984)
• Mortality among long-term employees of an Ontario asbestos-cement factory — M.M. Finkelstein (1983)
• Radiographic asbestosis is not a prerequisite for asbestos-associated lung cancer in Ontario asbestos-cement workers — M.M. Finkelstein (1997)
• Pulmonary function in asbestos cement workers: a dose-response study — M. Finkelstein (1986)
• Further follow-up study of workers from an asbestos cement factory — H.F. Thomas, I.T. Benjamin, et al. (1982)

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