OBJECTIVE To describe lung function in correlation with information on exposure to dust and fibers in soft tissue paper-producing factories in Germany. METHODS Ambient monitoring was performed for inhalable, respirable dust and fibers in nine soft tissue paper-producing factories. In a study group of 1,047 workers (189 control subjects, 240 workers with moderate exposure, and 618 workers with high exposure), spirometry (FVC, FEV(1)) was performed. Information on occupational history, duration of exposure, workshop within the company, former occupational exposures, and smoking habits were collected. By employing multiple linear regression modeling, the potentially confounding effects of age, sex, body mass index, smoking habits, and factory were incorporated into the analysis of FVC, FEV(1), and FEV(1) in percent of FVC (FEV(1)%FVC). By employing a logistic regression model, odds ratios were calculated for FVC < 80% predicted in different exposure subgroups. RESULTS The mean concentrations for inhalable, respirable, and fibrous dusts were 12.4 mg/m(3), 0.28 mg/m(3), and 420,000 fibers per cubic meter. With relation to cumulative dust and fiber exposure, a decrease of FVC from 105.4% predicted to 96.9% predicted (dust) and 97.1% predicted (fibers) in the subgroup with highest cumulative exposure was observed. For FEV(1), a decrease from 107.3% predicted to 103.0% predicted (dust) and 102.8% predicted (fibers) was found. The parameter estimates show dose-response relationships that are more pronounced for FVC compared to FEV(1). FEV(1)%FVC did not change significantly with increasing cumulative exposure, indicating a restrictive pattern of the findings. CONCLUSIONS Due to high ambient dust concentrations and the observed adverse effects on lung function, a reduction of dust exposure and secondary preventive measures is advised.