Particulate Exposure among Cadmium Workers: Is the Risk Due to Cigarette, Cadmium or Arsenic Particulates?

A nested case–control analysis was conducted of the 25 lung cancer cases identified on 1950–1982 death certificates among the Globe, Colorado, cohort of cadmium recovery workers who had previously been shown to have an excess of lung cancer. Three controls were chosen per case, matched by date and age at hire. Exposure variables included cigarette smoking history, estimated cumulative cadmium exposure in mg m⁻³-years and plant arsenic feedstock concentrations at time of hire. Cases were eight times more likely to have been cigarette smokers than controls. Cumulative mean cadmium exposures of the cases and controls were not significantly different overall or within date of hire periods. However, lung cancer risk and feedstock arsenic concentrations followed similar temporal patterns for hire periods (prior to 1926; 1926–1939; 1940–1969). Thus, differences in lung cancer risk appear to reflect temporal differences in arsenic exposure rather than differences in cadmium exposures.