title: Common environmental chemicals do not explain atopy contrast in the Finnish and Russian Karelia.
abstract: BACKGROUND
  Atopic allergy is much more common in Finnish compared with Russian Karelia, although these areas are geographically and genetically close. To explore the role of environmental chemicals on the atopy difference a random sample of 200 individuals, 25 atopic and 25 non-atopic school-aged children and their mothers, were studied. Atopy was defined as having at least one positive skin prick test response to 14 common inhalant and food allergens tested. Concentrations of 11 common environmental pollutants were measured in blood samples.
  
  
  RESULTS
  Overall, the chemical levels were much higher in Russia than in Finland, except for 2,2',4,4'-tetra-bromodiphenyl ether (BDE47). In Finland but not in Russia, the atopic children had higher concentrations of polychlorinated biphenyls and 1,1-Dichloro-2,2-bis-(p-chlorophenyl)-ethylene (DDE) than the non-atopic children. In Russia but not in Finland, the atopic mothers had higher DDE concentrations than the non-atopic mothers.
  
  
  CONCLUSIONS
  Higher concentrations of common environmental chemicals were measured in Russian compared with Finnish Karelian children and mothers. The chemicals did not explain the higher prevalence of atopy on the Finnish side.
authors.affiliation: Department of Allergy, Skin and Allergy Hospital, Helsinki University Hospital, Jatasalmentie 14a, 00830 Helsinki, Finland.
authors.forename: Jyri-Pekka
authors.initials: JP
authors.lastname: Koskinen
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland.
authors.forename: Hannu
authors.initials: H
authors.lastname: Kiviranta
authors.affiliation: Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Erkki
authors.initials: E
authors.lastname: Vartiainen
authors.affiliation: Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Jousilahti
authors.affiliation: North Karelia Center for Public Health, Joensuu, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Vlasoff
authors.affiliation: Department of Allergy, Skin and Allergy Hospital, Helsinki University Hospital, Jatasalmentie 14a, 00830 Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: von Hertzen
authors.affiliation: Department of Allergy, Skin and Allergy Hospital, Helsinki University Hospital, Jatasalmentie 14a, 00830 Helsinki, Finland.
authors.forename: Mika
authors.initials: M
authors.lastname: Mäkelä
authors.affiliation: Department of Health, National Institute for Health and Welfare, Helsinki, Finland ; Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland ; Hospital District of North Karelia, Joensuu, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Laatikainen
authors.affiliation: Department of Allergy, Skin and Allergy Hospital, Helsinki University Hospital, Jatasalmentie 14a, 00830 Helsinki, Finland.
authors.forename: Tari
authors.initials: T
authors.lastname: Haahtela
keywords: Allergy; Atopy; Environmental chemicals; Finnish Karelia; Russian Karelia