Silica dust and lung cancer: Results from the Nordic occupational mortality and cancer incidence registers

Autopsy studies of the relationship between silicosis and lung cancer have been mainly negative; but recent epidemiologic studies have indicated a positive association, and an excess lung cancer risk has been observed in some occupational groups with exposure to silica dust. For the further shedding of light on the possible association between silica dust and lung cancer, analysis was made on mortality and cancer incidence data available in census-based record linkage studies from the Nordic countries for males in occupational groups with potential exposure to silica dust. The study showed an excess lung cancer risk for foundry workers in all the Nordic countries and for miners in Sweden. These results were consistent with findings from previous in-depth epidemiologic studies. The lung cancer risk did not differ significantly from that of the respective national populations for males working in excavation; stone quarries; sand and gravel pits; and glass, porcelain, ceramic, and tile manufacture. Stonecutters, who are probably not exposed to known lung carcinogens at the workplace but in some places to high concentrations of silica dust, showed a significant excess lung cancer risk in both Finland and Denmark. Excess lung cancer risks furthermore were seen for Finnish miners, for Finnish males in excavation work, and for Danish glassworkers.