title: Biopersistent granular dust and chronic obstructive pulmonary disease: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Applying a systematic review to identify studies eligible for meta-analysis of the association between occupational exposure to inorganic dust and the development of chronic obstructive pulmonary disease (COPD), and conducting a meta-analysis.
  
  
  METHODS
  Searches of PubMed and Embase for the time period 1970-2010 yielded 257 cross-sectional and longitudinal studies on people exposed to inorganic dust at the workplace with data on lung function. These studies were independently abstracted and evaluated by two authors; any disagreement was resolved by a third reviewer. Of 55 publications accepted for meta-analysis, 27 investigated the effects of occupational exposure to biopersistent granular dust (bg-dust).
  
  
  METHODS
  A random effects meta-analysis allowed us to provide an estimate of the average exposure effect on spirometric parameters presented in forest plots. Between-study heterogeneity was assessed by using I(2) statistics, with I(2)>25% indicating significant heterogeneity. Publication bias was investigated by visual inspection of funnel plots. The influence of individual studies was assessed by dropping the respective study before pooling study-specific estimates.
  
  
  RESULTS
  The mean FEV1 of workers exposed to bg-dust was 160 ml lower or 5.7% less than predicted compared to workers with no/low exposure. The risk of an obstructive airway disease--defined as FEV1/FVC < 70%--increased by 7% per 1 mg · m(-3) respirable bg-dust.
  
  
  CONCLUSIONS
  Occupational inhalative exposure to bg-dust was associated with a statistically significant decreased FEV1 and FEV1/FVC revealing airway obstruction consistent with COPD.
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany.
authors.forename: Irene
authors.initials: I
authors.lastname: Brüske
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Thiering
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
authors.forename: Katharina
authors.initials: K
authors.lastname: Huster
authors.forename: Dennis
authors.initials: D
authors.lastname: Nowak
mesh_terms: D004391:Dust; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D016273:Occupational Exposure; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology* / Q000503:physiopathology
chemical_list: D004391:Dust