title: Air pollution modelling for birth cohorts: a time-space regression model.
abstract: To investigate air pollution effects during pregnancy or in the first weeks of life, models are needed that capture both the spatial and temporal variability of air pollution exposures.
  
  
  
  We developed a time-space exposure model for ambient NO2 concentrations in Bern, Switzerland. We used NO2 data from passive monitoring conducted between 1998 and 2009: 101 rural sites (24,499 biweekly measurements) and 45 urban sites (4350 monthly measurements). We evaluated spatial predictors (land use; roads; traffic; population; annual NO2 from a dispersion model) and temporal predictors (meteorological conditions; NO2 from continuous monitoring station). Separate rural and urban models were developed by multivariable regression techniques. We performed ten-fold internal cross-validation, and an external validation using 57 NO2 passive measurements obtained at study participant's homes.
  
  
  
  Traffic related explanatory variables and fixed site NO2 measurements were the most relevant predictors in both models. The coefficient of determination (R(2)) for the log transformed models were 0.63 (rural) and 0.54 (urban); cross-validation R(2)s were unchanged indicating robust coefficient estimates. External validation showed R(2)s of 0.54 (rural) and 0.67 (urban).
  
  
  
  This approach is suitable for air pollution exposure prediction in epidemiologic research with time-vulnerable health effects such as those occurring during pregnancy or in the first weeks of life.
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33 CH- 4056, Basel, Switzerland.|Division of Paediatric Pulmonology, Department of Paediatrics, Inselspital and University of Bern, Bern, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Proietti
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33 CH- 4056, Basel, Switzerland.
authors.forename: Edgar
authors.initials: E
authors.lastname: Delgado-Eckert
authors.affiliation: Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, 4051, Basel, Switzerland. danielle.vienneau@unibas.ch.|University of Basel, Basel, Switzerland. danielle.vienneau@unibas.ch.
authors.forename: Danielle
authors.initials: D
authors.lastname: Vienneau
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33 CH- 4056, Basel, Switzerland.|Division of Paediatric Pulmonology, Department of Paediatrics, Inselspital and University of Bern, Bern, Switzerland.
authors.forename: Georgette
authors.initials: G
authors.lastname: Stern
authors.affiliation: Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, 4051, Basel, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Tsai
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33 CH- 4056, Basel, Switzerland.|Division of Paediatric Pulmonology, Department of Paediatrics, Inselspital and University of Bern, Bern, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Latzin
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33 CH- 4056, Basel, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Frey
authors.affiliation: Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, 4051, Basel, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Röösli
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis; D006801:Humans; D008962:Models, Theoretical; D009585:Nitrogen Dioxide / Q000032:analysis*; D012044:Regression Analysis; D013557:Switzerland
chemical_list: D000393:Air Pollutants; D009585:Nitrogen Dioxide
keywords: Air pollution; Birth cohort; Exposure; NO2; Pregnancy