Acrylamide cohort mortality study

Our plain-English summary of Acrylamide cohort mortality study, by W. Sobel, G.G. Bond, T.W. Parsons, et al (British Journal of Industrial Medicine, 1986).

The study

• Authors: W. Sobel, G.G. Bond, T.W. Parsons, F.E. Brenner
• Journal: British Journal of Industrial Medicine
• Published: 1986;43(11):785-8
• Cited by: 47 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The mortality experience of 371 employees assigned to acrylamide monomer and polymerisation operations was examined with particular emphasis on cancers at sites identified from animal studies such as the central nervous system, thyroid gland, other endocrine glands, and mesotheliomas. A total of 29 deaths was observed up until 1982 (38.0 expected). No statistically significant excesses were noted in the total cohort and no deaths were found for the hypothesised sites of cancer. The observed deaths in the total cohort for the all cancers category were somewhat in excess (11 v 7.9); however, this was due entirely to excess cancers of the digestive tract and respiratory system in the subgroup with previous exposure to organic dyes. Among those employees not exposed to organic dyes, four deaths were due to malignancies versus 6.5 expected. This study does not support a cause effect relation between exposure to acrylamide at this work site and overall mortality, total malignant neoplasms, or any specific cancers.

In plain English

This retrospective cohort mortality study followed 371 white employees, six of them women, assigned to acrylamide monomer and polymerisation operations at the Dow Chemical Company's Michigan Division, from first potential exposure to 31 December 1982. The study concerned acrylamide, not asbestos; mesothelioma was examined because it had appeared in rats given acrylamide. Compared with United States white male rates, 29 deaths were observed against 38.0 expected. Cancer deaths numbered 11 against 7.9 expected, a non-significant excess the authors attributed entirely to digestive and respiratory cancers in workers with five or more years of earlier organic dye exposure. Excluding those 14 workers, four cancer deaths occurred against 6.5 expected. No deaths were found from cancers of the central nervous system, thyroid, other endocrine glands, or malignant mesothelioma. The authors concluded that the study does not support a cause effect relation between acrylamide exposure at this work site and overall mortality, total cancers, or any specific cancer. They noted that the possible confounding effect of acrylonitrile exposure was not formally assessed and that power to detect small site-specific increases was lower.

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: Retrospective cohort mortality study comparing the cohort's deaths with expected deaths from United States white male mortality rates (standardised mortality ratios). It gave particular emphasis to cancer sites seen in animal studies of acrylamide: central nervous system, thyroid, other endocrine glands and mesothelioma.
• Who was studied: 371 employees (white, including six women) assigned to acrylamide monomer and polymerisation operations at the Dow Chemical Company's Michigan Division, identified from census lists for 1955 to 1979. They were followed from first potential exposure to 31 December 1982. Fourteen of them had five or more years of earlier work with organic dyes and were also analysed separately.
• Exposure: Acrylamide during monomer and polymer production. Personal eight hour time weighted average exposures were between 0.1 and 0.6 mg/m3 from 1957 to 1970, and below 0.1 mg/m3 after 1970. Earlier levels were higher; the upper figure before 1957 is unreadable in the scan. Workers were also potentially exposed to acrylonitrile and to polyacrylamide dust containing residual acrylamide.
• Main results:
  • All causes, total cohort: 29 deaths observed against 38.0 expected (SMR 76, 95% CI 51-110). For the cohort excluding organic dye exposed workers: 20 observed against 31.5 expected (SMR 63, 95% CI 38-97).
  • All malignancies, total cohort: 11 observed against 7.9 expected (SMR 139, 95% CI 70-249), described as a non-significant excess.
  • The authors stated that the excess of all cancers in the total cohort was due entirely to excess cancers of the digestive tract and respiratory system in the subgroup with previous organic dye exposure. Fourteen individuals had five or more years of organic dye exposure.
  • All malignancies among employees without organic dye exposure (n = 357): four deaths observed against 6.5 expected (SMR 61, 95% CI 17-158).
  • No deaths were found for the hypothesised cancer sites: central nervous system, thyroid gland, other endocrine glands and malignant mesotheliomas.
  • Digestive tract cancer: 4 observed against 1.9 expected in the total cohort (SMR 202, 95% CI 57-539). Two of these were among employees without previous organic dye exposure (1.6 expected; SMR 124, 95% CI 15-452).
  • Respiratory system cancer: 4 observed against 2.9 expected in the total cohort (SMR 138, 95% CI 38-353). Among those without organic dye exposure there was 1 observed against 2.4 expected.
• The authors' conclusion: The authors concluded that the study does not support a cause effect relation between exposure to acrylamide at this work site and overall mortality, total malignant neoplasms, or any specific cancers.
• Limitations the authors state:
  • The possible confounding effect of acrylonitrile exposure was not formally assessed.
  • Possible ingestion or dermal absorption of acrylamide from polyacrylamide dusts could not be assessed.
  • The study had 80% power to detect a twofold increase in total cancers. Its power to detect small increases in site-specific cancers was lower.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Neoplasm.

Related studies

• Cause-specific mortality among male chemical workers — G.G. Bond, E.A. McLaren, et al. (1987)
• Mortality and cancer morbidity in cohorts of asbestos cement workers and referents — M. Albin, K. Jakobsson, et al. (1990)
• Cancer mortality in a cohort of asbestos textile workers — E. Pira, C. Pelucchi, et al. (2005)
• Mortality and cancer morbidity in a cohort of Canadian petroleum workers — R.J. Lewis, A.R. Schnatter, et al. (2003)
• Cumulative asbestos exposure and mortality from asbestos related diseases in a pooled analysis of 21 asbestos cement cohorts in Italy — F. Luberto, D. Ferrante, et al. (2019)
• Mortality from cancer and other causes in the Balangero cohort of chrysotile asbestos miners — E. Pira, C. Pelucchi, et al. (2009)

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