THE ABUNDANCE OF HOUSE DUST MITES (PYROGLYPHIDAE) IN DIFFERENT HOME TEXTILES IN EUROPE, IN RELATION TO OUTDOOR CLIMATES, HEATING AND VENTILATION

Abstract-In Europe, house dust mites of the family Pyroglyphidae are abundant producers of allergens in dwellings. Their prevalence in dwellings as well as their distribution among different types of home textiles vary in different localities in Europe. The main limiting factor for mite population growth is water activity. Water activity is closely related to relative humidity in the mite niche. Relative humidity in the mite niche is influenced by outdoor temperature and absolute air humidity, heating and ventilation. The mean January outdoor air temperature was determined. Based on outdoor temperatures and absolute air humidities, the length of heating season and length of mite population growth season for different home textiles were defined. These variables were validated with published data on mite abundance in mattresses and on floors in climatically distinct areas in Finland