Investigation of exposure to nickel and lung cancer mortality: case control study at aircraft engine factory

A case-control mortality study was performed at an aircraft engine factory to assess the possible association between exposure to nickel-containing compounds and death from lung cancer. Forty-two non-salaried male workers who died of lung cancer from 1966 to 1976 were identified from a chronological registry of death certificates that has been maintained by the company's medical department. Each of the decedents was matched with the next two non-salaried decedents in the registry who were of the same sex and comparable age (+/- 10 years), and who died of causes other than cancer. Without knowledge of the workmen's identities or causes of death, one of the authors classified the deceased workmen as exposed or non-exposed to nickel compounds during their employment. The proportion of workmen who died of lung cancer and were exposed to nickel (11/42) was found to be equal to the proportion of workmen who died of non-cancerous causes and were exposed to nickel (22/84). This study indicates that workers in an aircraft engine factory who were chronically exposed to low atmospheric concentrations of presumably weakly carcinogenic nickel compounds did not have any apparent increase in the relative risk of mortality from lung cancer prior to treatment.