Mortality Among Hardmetal Production Workers: German Historical Cohort Study
The aim of this study was to investigate a cohort in German hardmetal industry, especially relationship between exposures to cobalt, with and without tungsten, and risks of total and cause-specific mortality.Methods:
The cohort comprises blue-collar workers at three German plants who were employed in hardmetal processing. Individual cumulative exposures and long-term average concentrations were estimated for cobalt, nickel, tungsten, respirable, and inhalable dust. Standardized mortality ratios (SMRs) were calculated for external comparisons. Time-dependent multivariable Cox models were performed for internal analyses.Results:
Elevated SMRs were found for all-cause, heart diseases, and nonmalignant respiratory diseases mortality, but not for lung cancer. Internal analyses did not show increased risks for any endpoints, and no exposure–response relationship was indicated.Conclusions:
This study does not provide evidence for elevated lung cancer risks. Methodologic limitations, incomplete ascertainment of death causes in particular, impede conclusions about exposure effects.