Occupational exposure to crystalline silica and risk of lung cancer: a multicenter case-control study in Europe.

BACKGROUND: The role of crystalline silica dust as a possible cause of lung cancer has been controversial. Relatively few large community-based studies have been conducted to investigate the lung cancer risk from exposure to silica at low levels, taking into account potential confounding factors. METHODS: Detailed lifestyle and occupational information were collected from 2852 newly diagnosed cases of lung cancer and 3104 controls between 1998 and 2002 in 7 European countries. For each job held, local experts assessed the probability, intensity, and duration of silica exposure. RESULTS: Occupational exposure to crystalline silica was associated with an increased risk of lung cancer (odds ratio = 1.37; 95% confidence interval = 1.14-1.65). This risk was most apparent for the upper tertile of cumulative exposure (OR = 2.08; 95% CI = 1.49-2.90; P for trend <0.0001), duration of exposure (1.73; 1.26-2.39; P for trend = 0.0001) and weighted duration of exposure (1.88; 1.35-2.61; P for trend