Cancer risk among tetrafluoroethylene synthesis and polymerization workers

Am J Epidemiol. 2013 Aug 1;178(3):350-8. doi: 10.1093/aje/kws588. Epub 2013 Jul 4.

Abstract

Tetrafluoroethylene (TFE), a compound used for the production of fluorinated polymers including polytetrafluoroethylene, increases the incidence of liver and kidney cancers and leukemia in rats and mice. This is the first time the cancer risk in humans has been explored comprehensively in a cohort mortality study (1950-2008) that included all polytetrafluoroethylene production sites in Europe and North America at the time it was initiated. A job-exposure matrix (1950-2002) was developed for TFE and ammonium perfluoro-octanoate, a chemical used in the polymerization process. National reference rates were used to calculate standardized mortality ratios (SMRs) and 95% confidence intervals. Among 4,773 workers ever exposed to TFE, we found a lower rate of death from most causes, as well as increased risks for cancer of the liver (SMR = 1.27; 95% confidence interval: 0.55, 2.51; 8 deaths) and kidney (SMR = 1.44; 95% confidence interval: 0.69, 2.65; 10 deaths) and for leukemia (SMR = 1.48; 95% confidence interval: 0.77, 2.59; 12 deaths). A nonsignificant upward trend (P = 0.24) by cumulative exposure to TFE was observed for liver cancer. TFE and ammonium perfluoro-octanoate exposures were highly correlated, and therefore their separate effects could not be disentangled. This pattern of findings narrows the range of uncertainty on potential TFE carcinogenicity but cannot conclusively confirm or refute the hypothesis that TFE is carcinogenic to humans.

Keywords: cohort studies; mortality; neoplasms; occupational health; polytetrafluoroethylene; tetrafluoroethylene.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cause of Death
  • Chemical Industry*
  • Cohort Studies
  • Environmental Monitoring / statistics & numerical data
  • Europe / epidemiology
  • Female
  • Fluorocarbons / adverse effects*
  • Fluorocarbons / analysis
  • Fluorocarbons / chemical synthesis
  • Humans
  • Kidney Diseases / mortality
  • Kidney Neoplasms / chemically induced
  • Kidney Neoplasms / mortality*
  • Leukemia / chemically induced
  • Leukemia / mortality*
  • Liver Diseases / mortality
  • Liver Neoplasms / chemically induced
  • Liver Neoplasms / mortality*
  • Male
  • Occupational Diseases / chemically induced*
  • Occupational Diseases / mortality*
  • Occupational Exposure / analysis*
  • Polymerization
  • Risk Assessment
  • Survival Rate
  • United States / epidemiology

Substances

  • Fluorocarbons
  • tetrafluoroethylene