Mortality of factory workers in east London 1933-80

Our plain-English summary of Mortality of factory workers in east London 1933-80, by M.L. Newhouse, G. Berry, J.C. Wagner (British Journal of Industrial Medicine, 1985).

The study

• Authors: M.L. Newhouse, G. Berry, J.C. Wagner
• Journal: British Journal of Industrial Medicine
• Published: 1985;42(1):4-11
• Cited by: 92 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. 000495).

Abstract

The mortality of 3000 male factory workers, 1400 laggers, and 700 women factory workers in east London has been studied. The men were first employed between 1933 and 1964, the women between 1936 and 1942. Textiles were produced until the late 1950s as well as other asbestos products. Laggers were employed on contract in increasing numbers in later years. Crocidolite asbestos was used until the late 1950s as well as asmosite and chrysotile. Exposure of workers was graded according to the job into two categories, low/moderate and severe, and subdivided by duration of employment up to two years or longer. Mesothelial tumours accounted for 7.5% of the total mortality in men, and 9% in women with their longer follow up period. Lung cancer accounted for 20% of deaths in men and 14% in women. Both mesothelial tumours and lung cancer showed a dose response relationship. Histopathological examination of a series of predominantly postmortem specimens showed 22% of adenocarcinomas of lung among men and 21% in women. There was an excess of gastrointestinal tumours but no dose response relationship could be shown. Among severely exposed male factory workers there was an excess of deaths from cancer of the larynx and among severely exposed women of carcinoma of the breast and ovary. Twenty four deaths (2%) were due to asbestosis. There is an indication that the incidence of mesothelial tumours is declining but a further period of observation is required for confirmation.

In plain English

This study followed deaths among workers at an east London asbestos factory that made textiles and other products, using crocidolite until the mid-1950s as well as amosite and chrysotile. It covered men first employed between 1933 and 1964, contract laggers, and women who started between 1936 and 1942, with follow-up to 1980. Factory workers' jobs were graded subjectively as low/moderate or severe exposure, and by employment of up to two years or longer. Laggers were categorised separately and were not divided by duration of employment. Deaths were compared with the numbers expected from England and Wales death rates. Overall, 1249 of 4949 workers had died, against 872 expected. In men, lung cancer was associated with both severity and duration of exposure. Severely exposed men employed over two years had 67 lung cancer deaths against 13.9 expected. Mesothelioma killed 60 male factory workers, 13 laggers and 25 women, and its rates rose with severity and duration of exposure. Twenty-four deaths were from asbestosis. The authors estimated that between 22% and 27% of all deaths were due to asbestos exposure.

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 (follow-up of an earlier study): observed deaths compared with deaths expected from sex-, age- and period-specific death rates for England and Wales, using the subject-years method; the first 10 years after first employment were excluded
• Who was studied: Workers at an asbestos factory in the East End of London. The groups were male factory workers who worked entirely after the May 1933 asbestos regulations and were employed by 1964, laggers (1369 in the mortality table), and women who started work between 1936 and 1942 (vital status established for 77% of 932). The total was 4949 workers. Follow-up ran to December 1980 for men and June 1980 for women.
• Exposure: Work making asbestos textiles and other asbestos products such as prefabricated cement pipes, with crocidolite used until the mid-1950s as well as amosite and chrysotile. Factory workers' jobs were graded subjectively from light (1) to severe (6), then grouped as low/moderate or severe, and by employment of up to two years or longer. Laggers were categorised separately and were not divided by duration of employment, because they were mostly contract workers and many had worked with asbestos before or after this job.
• Main results:
  • Across all groups, 1249 of the 4949 workers had died, compared with 872 deaths expected.
  • Of the excess deaths, 154 were due to lung cancer (233 observed, 79 expected), 98 to mesothelioma, and 24 to asbestosis.
  • In men, lung cancer mortality was significantly associated with both category and duration of exposure (p less than 0.001).
  • Male factory workers with severe exposure for more than two years had 67 lung cancer deaths observed against 13.9 expected (observed to expected ratio 4.8, p less than 0.001).
  • In women, lung cancer was associated with duration of exposure (p less than 0.001).
  • Women who started work before age 25 had a lung cancer rate almost 12 times the expected figure, compared with five times for women who started older. After allowing for exposure imbalance this difference was significant (p less than 0.05). In men the ratios were similar in the two age groups.
  • By 1980, 60 male factory workers, 13 laggers and 25 women factory workers had died of mesothelial tumours.
  • The mesothelioma death rate per 100 000 years of exposure rose consistently with duration and severity of exposure. Laggers had a lower rate than severely exposed factory workers.
  • Mesothelioma deaths fell from 28 in 1971-5 to 17 in 1976-80, which was below the predicted range of 28 to 37. The reduction was not statistically significant at the 5% level.
  • Among 191 lung cancer specimens (mostly from necropsy), adenocarcinoma made up 22% in men (36 of 163) and 21% in women (6 of 28). The authors concluded that no particular cell type of lung cancer could be implicated.
  • Men had a statistically significant excess of deaths from gastrointestinal tumours, but there was no clear evidence of dose response.
  • Severely exposed male factory workers had three deaths from cancer of the larynx, with 0.81 expected (p less than 0.10).
  • Ovarian cancer: women with severe exposure for more than two years had 5 deaths observed against 0.9 expected, an excess that was statistically significant (p less than 0.01).
  • Breast cancer: there were 12 deaths, including 6 observed against 2.6 expected among women severely exposed for more than two years. There was no significant evidence of dose response.
  • Asbestosis deaths were most frequent among those severely exposed for more than two years: nine male factory workers, four laggers and five women. Six further asbestosis deaths occurred, all in men.
• The authors' conclusion: The authors concluded that there was evidence of a dose-response relationship for both mesothelial tumours and lung cancer, and that between 22% and 27% of all deaths were due to asbestos exposure. They regarded the reduced mesothelioma rate in 1976-80 as needing several more years of data for confirmation.
• Limitations the authors state:
  • Exposure grading was subjective because systematic dust surveys were not available.
  • Groups of workers exposed to a single fiber type could not be isolated.
  • There were too few women in the low/moderate category (99) for a sensitive comparison by exposure category.
  • The apparent decline in mesothelioma needs several more years of data before it can be considered real.
  • In the original tracing exercise only 30% of female subjects were traced, so a separate group of women was selected.
  • It is less certain to what extent the excess of other cancers could be attributed to asbestos exposure.

Topics

Medical terms in this study, explained in our Lexicon: Insulator, Crocidolite, Chrysotile, Lung Cancer, Adenocarcinoma, Laryngeal Cancer, Carcinoma.

Related studies

• Mortality from all cancers of asbestos factory workers in east London 1933-80 — G. Berry, M.L. Newhouse, et al. (2000)
• Correlation between fibre content of the lung and disease in east London asbestos factory workers — J.C. Wagner, M.L. Newhouse, et al. (1988)
• Correlation between fibre content of lung and disease in east London asbestos factory workers — R.M. Rudd (1989)
• Combined effect of asbestos and smoking on mortality from lung cancer and mesothelioma in factory workers — G. Berry, M.L. Newhouse, et al. (1985)
• Predictions of mortality from mesothelial tumours in asbestos factory workers — M.L. Newhouse, G. Berry (1976)
• Combined effect of asbestos exposure and smoking on mortality from lung cancer in factory workers — G. Berry, M.L. Newhouse, et al. (1972)

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