Mortality of workers in a French asbestos cement factory 1940-82

Our plain-English summary of Mortality of workers in a French asbestos cement factory 1940-82, by A.M. Alies-Patin, A.J. Valleron (British Journal of Industrial Medicine, 1985).

The study

• Authors: A.M. Alies-Patin, A.J. Valleron
• Journal: British Journal of Industrial Medicine
• Published: 1985;42(4):219-25
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001227).

Abstract

The mortality of a complete cohort of 1506 French asbestos cement workers employed for at least five years is related to the time elapsed since first exposure. The mortality from all causes (analysed by the "man-years method") has been found to be above normal only in those subjects employed for more than 20 years, with more than 35 years of follow up. Standardised mortality ratios for cancers of all sites (ICD 140-209) and pulmonary cancer (ICD 162-163.0) have been assessed in subjects whose first exposure dates go back more than 20 years. Mortalities from cancer of all sites and from pulmonary cancer have been detected in excess in workers employed for more than 20 years and originally hired when aged 25 or under.

In plain English

This study followed 1506 men who worked at least five years at an asbestos cement factory in Paray-Le-Monial, central France. The factory, opened in 1940, used mainly chrysotile asbestos, with chrysotile and crocidolite for tubes. Deaths to the end of 1982 were compared with those expected from French male death rates. There were 206 deaths, and the cause was identified for 179. Within 20 years of first exposure, overall mortality was lower than expected (SMR 0.77). More than 20 years after first exposure, men employed over 20 years had a significant excess of cancer deaths (SMR 1.68) and of pulmonary (lung and pleural) cancer (SMR 2.99). In the same period, men employed 5 to 20 years showed no statistically significant cancer excess (pulmonary cancer SMR 1.20), but the authors noted cancer deaths in this group may have been underestimated. The highest figure, SMR 5.19, was for pulmonary cancer in men first exposed at 25 or younger and employed over 20 years. Four men died of mesothelioma: one peritoneal and three pleural. The authors concluded the cancer excess may be explained by pulmonary cancer.

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: Cohort mortality study using the man-years method, comparing observed deaths with deaths expected from French male death rates (standardised mortality ratios, SMR)
• Who was studied: 1506 men employed for at least five years at an asbestos cement factory at Paray-Le-Monial, central France. Each man was followed from first employment (from 1940) to death or 31 December 1982. Women (administrative staff) and migrant workers were excluded.
• Exposure: Asbestos cement manufacture (corrugated or flat plates, tubes, moulded objects). Mainly chrysotile asbestos was used; tube making used a mixture of chrysotile and crocidolite.
• Main results:
  • There was no loss to follow-up. 206 deaths occurred in the cohort, and the cause of death was identified for 179 (87%).
  • In men whose time since first exposure did not exceed 20 years, all-cause mortality was significantly lower than expected: SMR 0.77 (99 observed, 128.04 expected). The authors attributed this to the healthy worker effect.
  • More than 20 years after first exposure, with duration of employment not taken into account, there was no significant excess in all-cause mortality.
  • All-cause mortality was highest in men employed more than 20 years whose time since first exposure exceeded 35 years: SMR 2.33 (9 observed, 3.87 expected), significantly greater than 1.
  • More than 20 years after first exposure, men employed more than 20 years had a significant excess of cancer of all sites: SMR 1.68 (23 observed, 13.72 expected). There was no excess from causes other than cancer (SMR 1.03).
  • In the same group (more than 20 years since first exposure, employed more than 20 years), the SMR for pulmonary cancer (lung and pleural) was 2.99 (9 observed, 3.01 expected), significantly greater than 1.
  • More than 20 years after first exposure, men employed 5 to 20 years showed no statistically significant excess: cancer of all sites SMR 0.94 (12 observed, 12.82 expected); pulmonary cancer SMR 1.20 (3 observed, 2.51 expected), not marked as significant. The authors cautioned that cancer deaths in this group may have been underestimated.
  • SMRs were higher in men first exposed at age 25 or younger. The greatest value, SMR 5.19 for pulmonary cancer (4 observed, 0.77 expected), was in men first exposed at age 25 or younger and employed more than 20 years.
  • There were four mesothelioma deaths. One was peritoneal mesothelioma, less than 20 years after first exposure. Three were pleural mesothelioma, more than 20 years after first exposure, with an average latency of less than 25 years.
  • All the men who died of mesothelioma except one (who died of pleural mesothelioma) had been in contact with crocidolite dust throughout their employment.
  • In men observed more than 20 years since first exposure, lung cancer death rates at ages 45-54, 55-64 and 65 and over were higher than 1970 French male rates. The largest difference, nearly six times, was at ages 45-54.
• The authors' conclusion: The authors concluded that the excess mortality from cancer of all sites, in men employed more than 20 years and hired before age 25, may be explained by an excess of deaths from pulmonary cancer (lung and pleura). They had no evidence of excess cancer deaths in men who worked less than 20 years, but cancer deaths in that group may have been underestimated.
• Limitations the authors state:
  • The results are limited by the quality of cause-of-death information. Of the 27 unidentified causes, 26 were in men employed less than 20 years.
  • The French method of registering deaths does not give the cause of individual deaths, so causes had to be obtained from hospitals, family doctors and relatives.
  • Follow-up may have been too short to show the full effect on mesothelioma: the mean time since first exposure was 22.4 years, and only 118 men were observed more than 35 years.
  • Mesothelioma deaths could have been underestimated because 27 causes of death were unidentified.
  • Cancer deaths among men employed less than 20 years may have been underestimated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile, Crocidolite.

Medical terms in this study, explained in our Lexicon: Asbestos-Cement.

Related studies

• Ventilatory decrements in former asbestos cement workers: a four year follow up — C.G. Ohlson, L. Bodin, et al. (1985)
• French cohort of the uranium processing workers: mortality pattern after 30-year follow-up — I. Guseva Canu, E. Cardis, et al. (2010)
• Impact of chemical exposure on cancer mortality in a French cohort of uranium processing workers — S. Zhivin, D. Laurier, et al. (2013)
• Incidence of cancer and mortality among workers exposed to mercury vapour in the Norwegian chloralkali industry — D.G. Ellingsen, A. Andersen, et al. (1993)
• Mortality among workers at Oak Ridge National Laboratory — D.B. Richardson, S. Wing, et al. (2013)
• Mortality and cancer morbidity in cohorts of asbestos cement workers and referents — M. Albin, K. Jakobsson, et al. (1990)

Browse more research in British Journal of Industrial Medicine, or return to medical research.