Mortality and cancer incidence in Ontario glass fiber workers
1 Program in Occupational Health and Environmental Medicine, McMaster University, 1200 Main Street, West Hamilton, Ontario M5G 2E9, Canada
2 Institute for Work & Health, 481 University Avenue, Toronto, Ontario M5G 2E9, Canada
Background In a previous cohort study of glass fiber manufacturing, we found a significant increase in lung cancer. This study extends the follow-up period.
Methods We conducted a historical prospective study of 2557 men employed in producing glass wool. We obtained work histories, causes and dates of death, and date and site of cancer diagnoses. We computed standardized mortality and incidence ratios (SMR, SIR).
Results The overall SMR for lung cancer was 163 (95% CI = 118–221). The SMR did not vary consistently by duration of employment and time since first employment. However, plant workers with >20 years' employment and >40 years since first exposure had an SMR for lung cancer of 282 (95% CI = 113–582). The SMR dropped with later date of first exposure, but the trend was non-significant. There was an unexpected overall increase in kidney cancer incidence.
Discussion The increase in lung cancer is greater than in other cohorts of glass fiber workers. Since exposure data are lacking from the early years of the plant, we cannot state if the excess was due to glass fibers, other work exposures or other reasons.
Keywords Cancer epidemiology; cohort; fibers; lung cancer
Correspondence to: Harry S. Shannon, Program in Occupational Health and Environmental Medicine, McMaster University, 1200 Main Street, West Hamilton, Ontario M5G 2E9, Canada. Tel: +1 905 525 9140, ext. 22333; fax: +1 905 528 8860; e-mail: shannonh{at}mcmaster.ca