A mortality study of a research, engineering, and metal fabrication facility in western New York State

Our plain-English summary of A mortality study of a research, engineering, and metal fabrication facility in western New York State, by M.J. Teta, M.G. Ott (American Journal of Epidemiology, 1988).

The study

• Authors: M.J. Teta, M.G. Ott
• Journal: American Journal of Epidemiology
• Published: 1988;127(3):540-51
• Cited by: 21 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. 000282).

Abstract

The mortality experience of 8,146 male employees of a research, engineering, and metal fabrication facility in Tonawanda, New York state was examined from 1946 to 1981. Potential workplace exposures included welding fumes, cutting oils, asbestos, organic solvents, and environmental ionizing radiation, as the result of disposal of wastes during the Manhattan Project of World War II. External comparisons with the US male population were supplemented by regional comparisons. For the total cohort, deficits were observed for all causes of death (standardized mortality ratio (SMR) = 87) and most non-cancer causes. The observed number of cancer deaths was close to expected (SMR = 99). There was an excess of connective and soft tissue cancer deaths, most notably in hourly employees hired prior to 1946. Among all hourly employees, there was an excess of respiratory cancer, which did not appear to be associated with length of employment. Mesothelioma was recorded as the cause of death for three decedents, two of whom were hourly employees who worked in production areas with high potential for asbestos exposure. The standardized mortality ratio for cirrhosis of the liver was elevated among long-term hourly employees hired prior to 1946. The roles of carbon tetrachloride exposure in the 1940s and alcohol consumption are discussed as possible contributory risk factors for the cirrhosis findings. The data do not provide evidence of radiation-induced cancers within this employee population.

In plain English

This cohort mortality study covered 8,146 men who worked at least one month between 1946 and 1981 at Union Carbide's Linde Division facility in Tonawanda, New York. It excluded the plant's Manhattan Project workers. Possible exposures included welding fumes, cutting oils, organic solvents, asbestos (used for insulation; fiber type not named) and environmental radiation. Compared with US white men, the whole group had fewer deaths than expected (SMR 87) and about the expected number of cancer deaths (SMR 99). Hourly workers had 42 per cent more respiratory cancer deaths than expected (SMR 142, 95 per cent confidence interval 114 to 176), an excess not related to length of employment. Three men, all long-term employees hired before 1946, died of mesothelioma (two pleural, one unspecified). Soft tissue cancer deaths (seven observed, 1.2 expected) were also elevated. So were cirrhosis deaths among long-term hourly men hired before 1946. The authors concluded the data did not support a concern about radiation-related effects. They noted that smoking and alcohol data were not available for the respiratory findings, and that mesothelioma is underreported on death certificates.

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 observed deaths with expected deaths based on US white male rates, plus regional (Niagara and Erie counties) rates
• Who was studied: 8,146 male employees (4,224 salary, 3,922 hourly) who worked at least one month during 1946 to 1981 at the Union Carbide Linde Division facility in Tonawanda, New York. The 1,551 Manhattan Project workers were excluded. Deaths were followed through 1981.
• Exposure: Potential workplace exposures to welding fumes, cutting oils, asbestos (fiber type not specified; used in the past), organic solvents including carbon tetrachloride in the 1940s, and environmental ionizing radiation from Manhattan Project waste disposal. No individual exposure measurements; comparisons were by pay type, period of hire and length of employment.
• Main results:
  • For the whole cohort compared with US rates, deaths from all causes were significantly fewer than expected (SMR = 87; 1,160 observed vs 1,333.9 expected).
  • For the whole cohort, total cancer (SMR = 99) and respiratory cancer (SMR = 107) deaths were close to expected.
  • The overall SMR was 102 for hourly employees and 55 for salary employees.
  • Among hourly employees there was a 42 per cent excess of respiratory cancer (SMR = 142; 87 observed vs 61.1 expected; 95 per cent CI 114 to 176). The authors found no relation with length of employment.
  • Among hourly men hired before 1946 with 10 or more years of employment, the respiratory cancer SMR was 174 (95 per cent CI 121 to 243). There was no trend with length of employment: the SMR was 182 in the less-than-five-years group (6 observed, 3.3 expected).
  • There were three mesothelioma deaths (two pleural, one unspecified), all among long-term employees hired before 1946. Two of the men were metalsmiths and one was a chemist/engineer.
  • The observed mesothelioma mortality rate was 1.9 deaths per 100,000. The authors compared this with an average expected incidence rate for males of 0.6 per 100,000, taken from another source. They noted that asbestos was used extensively at the plant for insulation, especially by welders and metal fabricators.
  • In the whole cohort there was a statistically significant excess of connective and other soft tissue cancer: 7 observed vs 1.2 expected deaths.
  • Among hourly men hired before 1946 with 10 or more years of employment, the cirrhosis of the liver SMR was 270 (17 observed, 6.3 expected). The authors reported indications from death certificates and plant medical records that at least 25 of the 37 cirrhosis deaths were alcohol-related.
  • The authors stated that the mortality data did not support a concern for radiation-related health effects. Lymphatic and blood-forming tissue cancer deaths were fewer than expected in both the hourly and the salary groups, and there were no bone cancer deaths.
• The authors' conclusion: The authors concluded that the cohort's overall low mortality presumably reflected healthy worker selection effects, a large proportion of salaried employees, and the absence of major occupational health effects in the cohort.
• Limitations the authors state:
  • For the respiratory cancer and respiratory disease findings among hourly employees, smoking, alcohol consumption and socioeconomic status were not available for analysis.
  • Mesothelioma is underreported on death certificates, so the true number of cases is likely higher.
  • Men hired from 1937 to 1945 were included only if still employed in 1946, which weighted that group toward longer employment.
  • Radiation exposures could not be reconstructed, and the study design could not detect small increases in risk from chronic low-level environmental exposures.
  • Definitive conclusions about cirrhosis were not possible without a systematic reconstruction of workplace exposures and patterns of alcohol consumption.

Topics

Medical terms in this study, explained in our Lexicon: standardized mortality ratio (SMR), Mesothelioma, Asbestos Exposure.

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