title: Modification of Traffic-related Respiratory Response by Asthma Control in a Population of Car Commuters.
abstract: BACKGROUND
  Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in- vehicle air pollution, and selected respiratory health outcomes by asthma control status.
  
  
  METHODS
  Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in 1 second (FEV1), and other metrics of respiratory health were measured precommute and 0, 1, 2, and 3 hours postcommute. We used mixed effects linear regression to evaluate associations between commute-related exposures and postcommute changes in metrics of respiratory health by level of asthma control.
  
  
  RESULTS
  We observed increased exhaled nitric oxide across all levels of asthma control compared with precommute measurements, with largest postcommute increases observed among participants with below-median asthma control (2 hours postcommute: 14.6% [95% confidence interval {CI} = 5.7, 24.2]; 3 hours postcommute: 19.5% [95% CI = 7.8, 32.5]). No associations between in-vehicle pollutants and percent of predicted FEV1 were observed, although higher PM2.5 was associated with lower FEV1 % predicted among participants with below-median asthma control (3 hours postcommute: -7.2 [95% CI = -11.8, -2.7]).
  
  
  CONCLUSIONS
  Level of asthma control may influence respiratory response to in-vehicle exposures experienced during rush-hour commuting.
authors.affiliation: From the aAir Pollution and Respiratory Health Branch, Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA; bDepartment of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA; cDepartment of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA; and dDivision of Pulmonary, Allergy and Critical Care, Department of Medicine, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Mirabelli
authors.forename: Rachel
authors.initials: R
authors.lastname: Golan
authors.forename: Roby
authors.initials: R
authors.lastname: Greenwald
authors.forename: Amit U
authors.initials: AU
authors.lastname: Raysoni
authors.forename: Fernando
authors.initials: F
authors.lastname: Holguin
authors.forename: Priya
authors.initials: P
authors.lastname: Kewada
authors.forename: Andrea
authors.initials: A
authors.lastname: Winquist
authors.forename: W Dana
authors.initials: WD
authors.lastname: Flanders
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Sarnat
mesh_terms: D000328:Adult; D000397:Air Pollution / Q000032:analysis; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D001944:Breath Tests; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016014:Linear Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D009569:Nitric Oxide; D052638:Particulate Matter / Q000032:analysis*; D013147:Spirometry; D014186:Transportation / Q000706:statistics & numerical data*; D014797:Vital Capacity
chemical_list: D052638:Particulate Matter; D009569:Nitric Oxide