title: Decreased respiratory symptoms after intervention in artificially ventilated offices in São Paulo, Brazil.
abstract: BACKGROUND
  The increase in work-related respiratory complaints in artificially ventilated buildings have multiple causes, and intervention studies are a valuable approach to understanding possible mechanisms.
  
  
  OBJECTIVE
  To analyze the effects of an intervention in a ventilation system with > 20 years of continuous use, and with a high rate of building-related respiratory complains.
  
  
  METHODS
  An epidemiologic study was done among individuals working in places with ventilation machinery and ducts with > 20 years of use, before and after intervention. Analysis of symptoms and logistic regression were performed to check the associations between air-conditioning intervention and reported symptoms.
  
  
  RESULTS
  The air-conditioning intervention showed a protective effect on building-related worsening of respiratory symptoms (odds ratio, 0.132; 95% confidence interval, 0.030 to 0.575), naso-ocular symptoms (odds ratio, 0.231; 95% confidence interval, 0.058 to 0.915), and persistent cough (odds ratio, 0.071; 95% confidence interval, 0.014 to 0.356).
  
  
  CONCLUSIONS
  Intervention in high-risk occupational locations can be effective in improving perceived indoor air quality.
authors.affiliation: Division of Allergy and Clinical Immunology, Internal Medicine Department, School of Medicine, Universisty of São Paulo, Brazil. gustavog@usp.br
authors.forename: Gustavo S
authors.initials: GS
authors.lastname: Graudenz
authors.forename: Jorge
authors.initials: J
authors.lastname: Kalil
authors.forename: Paulo H
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Maria do Rosário D O
authors.initials: Mdo R
authors.lastname: Latorre Md
authors.forename: Fabio F
authors.initials: FF
authors.lastname: Morato-Castro
mesh_terms: D000389:Air Conditioning / Q000009:adverse effects; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D006801:Humans; D009784:Occupational Diseases / Q000517:prevention & control*; D012140:Respiratory Tract Diseases / Q000517:prevention & control*; D011795:Surveys and Questionnaires