Filtration of airborne allergens in various households.

The filtration system investigated in this study uses the thermic convection caused by radiators for the adsorption of airborne particles. The effect of this filtration system on the reduction of clinical symptoms of allergic bronchial asthma was tested as well as its capability in retaining airborne allergens, in particular those of the house dust mite Dermatophagoides pteronyssinus (D. pter.), which are responsible for this special kind of asthma. Dust samples were taken before and after the heating season in households of 36 persons with D. pter. caused asthma. Their mite content was investigated using mite flotation and direct microscopy, their guanine content using the Acarex-test. An allergen extract obtained from the filters was tested on its allergen content by RAST-inhibition. It could be observed that compared to the preceding heating season 55% of the volunteers felt an improvement of their asthmatic symptoms. It was possible to extract allergens of D. pteronyssinus, house dust and mould from the filters. All these results show the capability of the filters to adsorb house dust mite (HDM) allergens.