title: Greenness and allergies: evidence of differential associations in two areas in Germany.
abstract: BACKGROUND
  Positive greenness effects on health are increasingly reported, although studies on allergic outcomes remain limited and conflicting. We examined whether residential greenness is associated with childhood doctor diagnosed allergic rhinitis, eyes and nose symptoms and aeroallergen sensitisation using two combined birth cohorts (GINIplus and LISAplus) followed from birth to 10 years in northern and southern Germany (Ntotal=5803).
  
  
  METHODS
  Mean residential greenness in a 500 m buffer around the 10-year home addresses was defined using the Normalized Difference Vegetation Index, a green biomass density indicator. Longitudinal associations were assessed per study area (GINI/LISA South and GINI/LISA North) using generalised estimation equations adjusted for host and environmental covariates.
  
  
  RESULTS
  Despite identical study designs and statistical modelling, greenness effects differed across the two study areas. Associations were elevated for allergic rhinitis and eyes and nose symptoms in the urban GINI/LISA South area. In contrast, risk estimates were significantly below one for these outcomes and aeroallergen sensitisation in rural GINI/LISA North. Area-specific associations were similar across buffer sizes and addresses (birth and 6 years) and remained heterogeneous after air pollution and population density stratification.
  
  
  CONCLUSIONS
  Existing and future single-area studies on greenness and green spaces should be interpreted with caution.
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Elaine
authors.initials: E
authors.lastname: Fuertes
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany Division of Metabolic and Nutritional Medicine, Dr von Hauner Children's Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Iana
authors.initials: I
authors.lastname: Markevych
authors.affiliation: Department of Pediatrics, Marien-Hospital Wesel, Wesel, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: von Berg
authors.affiliation: Department of Pediatrics, Technical University of Munich, Munich, Germany.
authors.forename: Carl-Peter
authors.initials: CP
authors.lastname: Bauer
authors.affiliation: Department of Pediatrics, Marien-Hospital Wesel, Wesel, Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Berdel
authors.affiliation: Division of Paediatric Gastroenterology and Hepatology, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Koletzko
authors.affiliation: IUF-Leibniz Research Institute for Environmental Medicine, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Sugiri
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects; D004777:Environment; D004779:Environment Design; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008137:Longitudinal Studies; D016017:Odds Ratio; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology*; D012424:Rural Population; D011795:Surveys and Questionnaires; D014505:Urban Population; D057948:Viridiplantae
chemical_list: D000393:Air Pollutants