ALLERGEN CONTENT IN DUST FROM HOMES AND SCHOOLS IN NORTHERN NORWAY INRELATION TO SENSITIZATION AND ALLERGY SYMPTOMS IN SCHOOLCHILDREN

Background Previous studies have shown a high prevalence of atopic dis eases among school children in the community of Sor-Varanger. Moreover , animal dander followed by pollen and house dust mite, were the most common allergens in skin prick tests. Objective To assess the allergen content in homes (Living-rooms and mattresses) and classrooms of chil dren Living in an arctic area at 70 degrees north. The presence of all ergens in homes and schools and their relationship to atopy was of par ticular interest. Methods Dust samples from 38 homes and seven schools in northern Norway were collected by vacuum cleaning. The presence of allergens of dop birch, timothy, Cladosporium herbarum, codfish and h en egg-white was investigated by radio-allergosorbent test (RAST) inhi bition and the presence of major allergens of cat Felis domesticus (Fe l d I) and house dust mites (HDM) Dermatophagoides pteronyssinus (Der p I) and Dermatophagoides farinae (Der f I) by enzyme-linked immunosor bent assay (ELISA). Results Mattresses contained significantly more du st per unit area than living-rooms and classrooms, No statistically si gnificant differences in allergen content for dog, birch, timothy, Cla dosporium, codfish and hen egg-white were seen between HDM-sensitized and non-atopic children. Most dust samples contained dog allergens wit h the highest allergenic activity found in living-rooms of those keepi ng dogs. An increased level of Fel d I was detected In only one of 38 samples from living-rooms (this family kept a cat) and in 25 of 38 sam ples from mattresses with ranges from 24 to 84 ng/m(2). The highest co ncentrations were found in mattresses of children keeping cats, Increa sed levels (greater than or equal to 25 ng/m(2)) of Der p I were found only in homes and virtually only in mattresses of HDM-sensitized chil dren. An increased level of. Der f I was found in only one case, i.e. in the mattress of an HDM-sensitized child where additionally Der p I and HDMs were demonstrated microscopically. When relating Der p I to H DM-sensitization an odds ratio of more than 16 (95% CI: 1.6-394.3) was found. All extracts from living-rooms included codfish allergens, Low RAST inhibition values were detected for hen egg-white, Cladosporium, birch and timothy pollen in most samples, Furthermore, the study demo nstrated that dust from schools was relatively free of allergens. Conc lusion Previous findings indicating that the main allergen exposure pr oblem in this geographical area is that of pet allergens were confirme d.