title: Protection from childhood asthma and allergy in Alpine farm environments-the GABRIEL Advanced Studies.
abstract: BACKGROUND
  Studies on the association of farm environments with asthma and atopy have repeatedly observed a protective effect of farming. However, no single specific farm-related exposure explaining this protective farm effect has consistently been identified.
  
  
  OBJECTIVE
  We sought to determine distinct farm exposures that account for the protective effect of farming on asthma and atopy.
  
  
  METHODS
  In rural regions of Austria, Germany, and Switzerland, 79,888 school-aged children answered a recruiting questionnaire (phase I). In phase II a stratified random subsample of 8,419 children answered a detailed questionnaire on farming environment. Blood samples and specific IgE levels were available for 7,682 of these children. A broad asthma definition was used, comprising symptoms, diagnosis, or treatment ever.
  
  
  RESULTS
  Children living on a farm were at significantly reduced risk of asthma (adjusted odds ratio [aOR], 0.68; 95% CI, 0.59-0.78; P< .001), hay fever (aOR, 0.43; 95% CI, 0.36-0.52; P< .001), atopic dermatitis (aOR, 0.80; 95% CI, 0.69-0.93; P= .004), and atopic sensitization (aOR, 0.54; 95% CI, 0.48-0.61; P< .001) compared with nonfarm children. Whereas this overall farm effect could be explained by specific exposures to cows, straw, and farm milk for asthma and exposure to fodder storage rooms and manure for atopic dermatitis, the farm effect on hay fever and atopic sensitization could not be completely explained by the questionnaire items themselves or their diversity.
  
  
  CONCLUSIONS
  A specific type of farm typical for traditional farming (ie, with cows and cultivation) was protective against asthma, hay fever, and atopy. However, whereas the farm effect on asthma could be explained by specific farm characteristics, there is a link still missing for hay fever and atopy.
authors.affiliation: Asthma and Allergy Research Group, University Children's Hospital, Munich, Germany. sabina.illi@med.uni-muenchen.de
authors.forename: Sabina
authors.initials: S
authors.lastname: Illi
authors.forename: Martin
authors.initials: M
authors.lastname: Depner
authors.forename: Jon
authors.initials: J
authors.lastname: Genuneit
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Horak
authors.forename: Georg
authors.initials: G
authors.lastname: Loss
authors.forename: Christine
authors.initials: C
authors.lastname: Strunz-Lehner
authors.forename: Gisela
authors.initials: G
authors.lastname: Büchele
authors.forename: Andrzej
authors.initials: A
authors.lastname: Boznanski
authors.forename: Hanna
authors.initials: H
authors.lastname: Danielewicz
authors.forename: Paul
authors.initials: P
authors.lastname: Cullinan
authors.forename: Dick
authors.initials: D
authors.lastname: Heederik
authors.forename: Charlotte
authors.initials: C
authors.lastname: Braun-Fahrländer
authors.forename: Erika
authors.initials: E
authors.lastname: von Mutius
mesh_terms: D000383:Agriculture; D000818:Animals; D001249:Asthma / Q000453:epidemiology* / Q000517:prevention & control*; D001317:Austria; D002415:Cats; D002417:Cattle; D002648:Child; D004285:Dogs; D004781:Environmental Exposure; D005858:Germany; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology* / Q000517:prevention & control*; D007073:Immunoglobulin E / Q000097:blood; D011044:Poland; D011200:Poultry; D015995:Prevalence; D012424:Rural Population; D012756:Sheep; D011795:Surveys and Questionnaires; D013552:Swine; D013557:Switzerland
chemical_list: D007073:Immunoglobulin E