Original article

Scand J Work Environ Health 2010;36(1):71-79    pdf

doi:10.5271/sjweh.2875 | Published online: 13 Nov 2009, Issue date: 00 Jan 2010

Cancer incidence among short- and long-term workers in the Norwegian silicon carbide industry

by Bugge MD, Kjuus H, Martinsen JI, Kjærheim K

Objectives A previous study among workers in the Norwegian silicon carbide industry, followed until 1996, revealed an excess incidence of lung and total cancer. The present study adds nine years of follow-up and focuses on cancer risk among short- and long-term workers, based on the assumption that these two groups have different exposure and lifestyle characteristics.

Methods The total cohort for this study comprised 2612 men employed for >6 months between 1913 and 2003. The follow-up period for cancer was 1953–2005. Short-term workers were defined as having <3 years of total employment in the industry. We estimated standardized incidence ratios (SIR) using national rates as the expected values.

Results Among the short-term workers, we observed an overall excess incidence of cancer [SIR 1.4, 95% confidence interval (95% CI) 1.2–1.6], with an excess of lung cancer (SIR 2.6, 95% CI 1.9–3.5) as the most important contributing factor. The long-term workers also had an excess incidence of total cancer (SIR 1.2, 95% CI 1.1–1.3) and lung cancer (SIR 1.7, 95% CI 1.3–2.2). We also observed an increased risk of cancers at other sites, specifically among short-term workers.

Conclusions We observed an increased risk of cancer (especially in the lung but also at other sites) among both short- and long-term workers. Dust exposure in the silicon carbide industry may have contributed to the increased risk among long-term workers, whereas the increased risk among short-term workers may be due to a combination of occupational and lifestyle factors.

This article refers to the following text of the Journal: 1999;25(3):207-214