title: Respiratory health before and after the opening of a road traffic tunnel: a planned evaluation.
abstract: OBJECTIVE
  The construction of a new road tunnel in Sydney, Australia, and concomitant reduction in traffic on a major road presented the opportunity to study the effects of this traffic intervention on respiratory health.
  
  
  METHODS
  We made measurements in a cohort of residents in the year before the tunnel opened (2006) and in each of two years afterwards (2007-2008). Cohort members resided in one of four exposure zones, including a control zone. Each year, a respiratory questionnaire was administered (n = 2,978) and a panel sub-cohort (n = 380) performed spirometry once and recorded peak expiratory flow and symptoms twice daily for nine weeks.
  
  
  RESULTS
  There was no consistent evidence of improvement in respiratory health in residents living along the bypassed main road, despite a reduction in traffic from 90,000 to 45,000 vpd. Residents living near tunnel feeder roads reported more upper respiratory symptoms in the survey but not in the panel sub-cohort. Residents living around the tunnel ventilation stack reported more upper and lower respiratory symptoms and had lower spirometric volumes after the tunnel opened. Air pollutant levels measured near the stack did not increase over the study period.
  
  
  CONCLUSIONS
  The finding of adverse health effects among residents living around the stack is unexpected and difficult to explain, but might be due to unmeasured pollutants or risk factors or an unrecognized pollutant source nearby. The lack of improvement in respiratory health among people living along the bypassed main road probably reflects a minimal change in exposure due to distance of residence from the road.
authors.affiliation: Woolcock Institute of Medical Research, Sydney, Australia. christine.cowie@sydney.edu.au
authors.forename: Christine T
authors.initials: CT
authors.lastname: Cowie
authors.forename: Nectarios
authors.initials: N
authors.lastname: Rose
authors.forename: Wafaa
authors.initials: W
authors.lastname: Ezz
authors.forename: Wei
authors.initials: W
authors.lastname: Xuan
authors.forename: Adriana
authors.initials: A
authors.lastname: Cortes-Waterman
authors.forename: Elena
authors.initials: E
authors.lastname: Belousova
authors.forename: Brett G
authors.initials: BG
authors.lastname: Toelle
authors.forename: Vicky
authors.initials: V
authors.lastname: Sheppeard
authors.forename: Guy B
authors.initials: GB
authors.lastname: Marks
mesh_terms: D000397:Air Pollution / Q000009:adverse effects; D001315:Australia; D015331:Cohort Studies; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D011634:Public Health; D012119:Respiration; D012129:Respiratory Function Tests; D011795:Surveys and Questionnaires