title: Associations of long-term exposure to air pollution and road traffic noise with cognitive function-An analysis of effect measure modification.
abstract: Adverse effects of traffic-related air pollution (AP) and noise on cognitive functions have been proposed, but little is known about their interactions and the combined effect of co-exposure.
  
  
  
  Cognitive assessment was completed by 4086 participants of the population-based Heinz Nixdorf Recall cohort study using five neuropsychological subtests and an additively calculated global cognitive score (GCS). We assessed long-term residential concentrations for size-fractioned particulate matter (PM) and nitrogen oxides with land use regression. Road traffic noise (weighted 24-h (LDEN) and night-time (LNIGHT) means) was assessed according to the EU directive 2002/49/EC. Linear regression models adjusted for individual-level characteristics were calculated to estimate effect modification of associations between AP and noise with cognitive function. We used multiplicative interaction terms and categories of single or double high exposure, dichotomizing the potential effect modifier at the median (AP) or at an a priori defined threshold (road traffic noise).
  
  
  
  In fully adjusted models, high noise exposure increased the association of AP with cognitive function. For example, for an interquartile range increase of PM2.5(IQR 1.43), association s with GCS were: estimate (β)=-0.16 [95% confidence interval: -0.33; 0.01] and β=-0.48 [-0.72; -0.23] for low and high LDEN, respectively. The association of noise with GCS was restricted to highly AP-exposed participants. We observed stronger negative associations in those participants with double exposure compared to the addition of effect estimates of each single exposure.
  
  
  
  Our study suggests that AP and road traffic noise might act synergistically on cognitive function in adults.
authors.affiliation: Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany; Faculty of Medicine, University of Latvia, Latvia. Electronic address: Liliana.Civjane@lu.lv.
authors.forename: Lilian
authors.initials: L
authors.lastname: Tzivian
authors.affiliation: Department of Neurology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: Martha
authors.initials: M
authors.lastname: Jokisch
authors.affiliation: Department of Neurology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Winkler
authors.affiliation: Department of Neurology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Weimar
authors.affiliation: Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Frauke
authors.initials: F
authors.lastname: Hennig
authors.affiliation: IUF Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Sugiri
authors.affiliation: Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Soppa
authors.affiliation: Institute of Medical Sociology, Centre for Health and Society, Medical Faculty, Heinrich-Heine-University Düsseldorf, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Dragano
authors.affiliation: Institute for Medical Informatics, Biometry and Epidemiology, University Duisburg-Essen, Essen, Germany.
authors.forename: Raimund
authors.initials: R
authors.lastname: Erbel
authors.affiliation: Institute for Medical Informatics, Biometry and Epidemiology, University Duisburg-Essen, Essen, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Jöckel
authors.affiliation: Institute for Medical Informatics, Biometry and Epidemiology, University Duisburg-Essen, Essen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Moebus
authors.affiliation: Institute of Occupational, Social and Environmental Medicine, Centre for Health and Society, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Hoffmann
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D003071:Cognition; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D005260:Female; D006798:Housing; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009589:Nitrogen Oxides / Q000009:adverse effects / Q000032:analysis; D009624:Noise, Transportation / Q000009:adverse effects*; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D011446:Prospective Studies
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter
keywords: Air pollution; Cognitive function; Effect modification; Traffic noise