title: Acute effects of urban air pollution on respiratory health of children with and without chronic respiratory symptoms.
abstract: OBJECTIVE
  To investigate to what extent different components of air pollution are associated with acute respiratory health effects in children with and without chronic respiratory symptoms.
  
  
  METHODS
  During three consecutive winters starting in 1992-3, peak expiratory flow (PEF) and respiratory symptoms were registered daily in panels of children of 7-11 years old with and without symptoms, living in urban areas with high traffic intensity in The Netherlands. Simultaneously, panels of children living in non-urban areas were studied. Daily measurements of particles with aerodynamic diameter < 10 microns (PM10), black smoke (BS), sulphate, SO2, and NO2 were performed in both areas.
  
  
  RESULTS
  The contrast in particle concentrations (PM10, BS, and sulphate) between urban and non-urban areas was small, but there was more contrast in the concentrations of SO2 and NO2. In children with symptoms from both areas, significant associations were found between PM10, BS, and sulphate concentrations and the prevalence of symptoms of the lower respiratory tract (LRS) and decrements in PEF. Particle concentrations were also associated with use of bronchodilators in the urban areas, but not in the non-urban areas. After stratification by use of medication, stronger associations were found in children who used medication than in children who did not use medication. The magnitude of the estimated effects was in the order of a twofold increase in the use of bronchodilators, a 50% increase in LRS, and an 80% increase in decrements in PEF for a 100 micrograms/m3 increase in the 5 day mean PM10 concentration. In children without symptoms, significant associations were found between concentrations of PM10 and BS and decrements in PEF in both areas, but these associations were smaller than those for children with symptoms. No associations with respiratory symptoms were found.
  
  
  CONCLUSIONS
  The results suggest that children with symptoms are more susceptible to the effects of particulate air pollution than children without symptoms, and that use of medication for asthma does not prevent the adverse effects of particulate air pollution in children with symptoms.
authors.affiliation: Environmental and Occupational Health Group, University of Wageningen, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: van der Zee
authors.forename: G
authors.initials: G
authors.lastname: Hoek
authors.forename: H M
authors.initials: HM
authors.lastname: Boezen
authors.forename: J P
authors.initials: JP
authors.lastname: Schouten
authors.forename: J H
authors.initials: JH
authors.lastname: van Wijnen
authors.forename: B
authors.initials: B
authors.lastname: Brunekreef
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D002648:Child; D002908:Chronic Disease; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D006801:Humans; D009426:Netherlands / Q000453:epidemiology; D009589:Nitrogen Oxides / Q000009:adverse effects; D010366:Peak Expiratory Flow Rate; D012120:Respiration Disorders / Q000139:chemically induced* / Q000503:physiopathology; D012423:Rural Health; D012621:Seasons; D013461:Sulfur Oxides / Q000009:adverse effects; D014504:Urban Health
chemical_list: D009589:Nitrogen Oxides; D013461:Sulfur Oxides