title: Childhood cat allergen exposure in three European countries: The AIRALLERG study.
abstract: BACKGROUND
  Cat allergen is a major cause of morbidity among sensitised asthma patients, but little is known about distribution of cat allergen exposure and its determinants in homes.
  
  
  METHODS
  We measured cat allergen and potential determinants of cat allergen levels in more than 1000 homes. House dust was collected from children's mattresses and living room floors in approximately 360 homes in The Netherlands, Sweden and Germany and analysed for Fel d 1 in one central laboratory. Exposure was expressed both in concentration (ng/g) and in loads (ng/m2).
  
  
  RESULTS
  Levels on mattresses were similar in Sweden and Germany but higher on Dutch mattresses. Dutch floors had higher concentrations than Swedish floors, which had higher concentrations than German floors. The differences in load were less clear. Cat allergen on mattress and floor were moderately to highly correlated. The most important variable quantifying cat allergen variation was the presence of a cat. Floor cover type and last time that floor was vacuumed were important in all three countries. The ratio of cat allergen loads between mattresses from homes with and without cats was higher for Sweden and Germany than for The Netherlands. This is likely related to higher prevalence of cat ownership in The Netherlands which leads to more contamination of homes in which cats were never held. Dust samples from 27-35% of mattresses from homes without cats contained more than 1000 ng/g cat allergen.
  
  
  CONCLUSIONS
  With the exception of cat ownership and floor cover, questionnaire data on housing characteristics did not accurately predict cat allergen in the home.
authors.affiliation: Division of Environmental and Occupational Health, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Mariëlla
authors.initials: M
authors.lastname: Giovannangelo
authors.forename: Ulrike
authors.initials: U
authors.lastname: Gehring
authors.forename: Emma
authors.initials: E
authors.lastname: Nordling
authors.forename: Marieke
authors.initials: M
authors.lastname: Oldenwening
authors.forename: Siegfried
authors.initials: S
authors.lastname: de Wind
authors.forename: Tom
authors.initials: T
authors.lastname: Bellander
authors.forename: Catarina
authors.initials: C
authors.lastname: Almqvist
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
authors.forename: Gerard
authors.initials: G
authors.lastname: Hoek
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D000485:Allergens / Q000032:analysis*; D000818:Animals; D001513:Beds; D002415:Cats; D002675:Child, Preschool; D004391:Dust / Q000032:analysis*; D004731:Endotoxins / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis; D005430:Floors and Floorcoverings; D005858:Germany; D006023:Glycoproteins / Q000032:analysis*; D006798:Housing; D006801:Humans; D009426:Netherlands; D013548:Sweden
chemical_list: D000485:Allergens; D004391:Dust; D004731:Endotoxins; D006023:Glycoproteins; C059296:Fel d 1 protein, Felis domesticus