Respiratory cancer mortality and incidence in an updated cohort of Canadian nickel production workers.

Respiratory cancer mortality and incidence were examined in an updated cohort of >56,000 Canadian nickel mining and refining workers. There was little evidence to suggest increased lung cancer risk in workers who had no experience in high-risk sintering operations that were closed by 1972, apart from that which would be expected from probable increased smoking prevalence relative to the comparison population. There was no substantive evidence of increased laryngeal cancer risk in the cohort, nor was there evidence of increased pharyngeal cancer risk in nonsinter workers. Nasal cancer incidence was elevated in nonsinter workers, but excess risks appeared to be confined to those hired prior to 1960. These findings lead us to tentatively conclude that occupationally-related respiratory risks in workers hired over the past 45 years are either very low or nonexistent.

Nonrespiratory mortality and cancer incidence in a cohort of Canadian nickel workers.

Mortality and cancer incidence were examined for an updated cohort of nonsinter nickel workers in Sudbury and Port Colborne, Ontario, Canada. Abstract results are provided for those with ≥ 15 years since first exposure. For circulatory disease mortality, significant elevations were observed overall in many Sudbury work areas and in Port Colborne staff. Underground miners, with first exposure before 1960, displayed significant elevations for pneumoconiosis, as well as silicosis and anthrasilicosis, likely due to crystalline silica. Significant elevations in colorectal cancer incidence were observed in Sudbury underground mining, mining maintenance, and maintenance work areas. Given a case-control study is not practical, the next cohort update should include more detailed occupational exposure assessment, including dust exposure, diesel engine emissions, solvents, various metals, silica, and sulphur dioxide.

Injury mortality in a cohort of mining, smelting, and refining workers in Ontario.

Injury mortality was followed up from 1950 to 2000 in a cohort of 56,576 nickel workers. Injury fatalities were elevated throughout the cohort of never sinter plant workers (SMR = 134, 95% CI [129, 140]). Elevations were also observed in injury mortality subcategories of road, rail, and air (SMR = 137, 95% CI [127, 147]); boating and swimming (SMR = 150, 95% CI [128, 176]); suicide and possible suicide (SMR = 124, 95% CI [114, 135]); and possibly job-related accidents (SMR = 160, 95% CI [145, 175]). The results were largely attributed to underground miners, with 61.4% of all injury mortality (SMR = 162; 95% CI [153, 171]). Occupational etiology could not be ascertained; however, compiled workplace injury fatalities are presented separately. Recommendations include delivery of injury prevention and wellness programs in partnership with the local health unit and other stakeholders.

Mortality and cancer incidence in a copper-zinc cohort.

Previous studies of copper-zinc workers have primarily observed significant increases in lung and other respiratory cancers. This study concurrently examined cancer incidence and cause-specific mortality for a cohort of workers at a copper-zinc producer in Ontario, Canada, from 1964 to 2005. Significant elevations in lung cancer incidence were observed for males in the overall cohort (standardized incidence ratio [SIR] = 124, 95% confidence interval [CI] = 102-150) and for surface mine (SIR = 272, 95% CI = 124-517), concentrator (SIR = 191, 95% CI = 102-327), and central maintenance (SIR = 214, 95% CI = 125-343) employees. Significant elevations of non-Hodgkin's lymphoma incidence were observed for male underground mine employees (SIR = 232, 95% CI = 111-426). Occupational etiology cannot be ascertained with the current exploratory study design. Future studies could (1) incorporate exposure assessment for subgroups within the existing cohort and (2) determine the efficacy of wellness programs in partnership with the local health unit.