Mortality and cancer incidence in a nickel cohort.

BACKGROUND Previous studies of nickel workers have primarily noted significant early increases in lung and nasal cancers and for various types of accidents. AIMS To examine cancer incidence and mortality, concurrently, for a cohort of male nickel workers at a major nickel and copper producer in Sudbury, Ontario, Canada. METHODS From January 1964 to December 2001, nominal roll and work history information were linked to Ontario health data and mortality and cancer incidence were compared to the Ontario population. RESULTS There were 1984 (19%) deaths and 1127 (11%) incident cancers (n = 10,253). Significant elevations in mortality were observed for accidents, poisoning and violence; for possibly job-related accidents among those with <15 years since first hire [standardized mortality ratio (SMR) = 133, 95% CI: 111-158; SMR = 241, 95% CI: 159-351, respectively] and for accidents in those with > or =15 years since first hire (SMR = 123, 95% CI: 104-144). Significant elevations were also observed for accidents, poisoning and violence for those with 6 months to 14 years work experience and for lung cancer incidence and mortality for those with 15-29 years work experience (SMR = 128, 95% CI: 107-153). Incident lung cancers were significantly elevated for those hired in the 1940s and 1960s. CONCLUSIONS Significant lung cancer mortality and incidence elevations were observed for the cohort and underground workers with increased time since first hire, for those hired during early periods of operation and for those with longer durations of employment. Further aetiological study is required as occupational aetiology could not be ascertained.