407 Chronic-obstructive pulmonary disease (COPD) caused by inhalation of inorganic dust at the workplace - Systematic Review and Metaanalysis

Abstract

Objective A systematic review of the scientific medical literature on COPD and the inhalative exposure to inorganic dust and a metaanalysis. Methods The search was done in Medline/EMBASE. The quality of selected papers was evaluated on the basis of the Newcastle-Ottawa Scale and the recommendations of the Cochrane Collaboration. Metaanalysis of the results of pulmonary function tests were evaluated separately for bio-persistent granular dust (BGD) and silica containing dust by random-effects models. Results In cross-sectional analyses subjects occupationally exposed to BGD had on average a 160 ml lower FEV1 and the predicted value for FEV1 was decreased by 5.7%. The ratio of FEV1/FVC was also significantly decreased. Related to a cumulative BGS- exposure of 1 mg/m³·year FEV1 was decreased by 1.6 ml. The Odds Ratio for obstructive pulmonary test results (FEV1/FVC <70%) was 1.07 per 1 mg/m3 BGD at the workplace. Longitudinal analyses showed a yearly decline of FEV1 of 6.3 ml in BGD-exposed and of 11.8 ml in silica exposed persons compared to non/low-exposed persons in addition to age-dependent decline. A study of uranium miners (WISMUT Company) in Germany showed that the cumulative exposure to 1 mg/m3 pure respirable silica dust decreased the ratio of FEV1/FVC by 2.75%. The risk of COPD stage I increased (OR 1.81 pro 1” mg/m3·year) related to the exposure of pure respirable silica dust. In relation to COPD stage II + the cumulative doubling dose was 2 mg/m³·year pure respirable silica dust. All cited results were statistically significant (p < 0.01 to p < 0.001). Funnel plots did not indicate major publication bias. Conclusion Review and metaanalysis showed a statistically positive association between the inhalative exposure to BGD at the workplace and a decreased FEV1 in cross-sectional as well as in longitudinal analyses. Funded by the Federal Ministry of Labour and Social Affairs (“Bundesministerium für Arbeit und Soziales”).