Relationship between indoor allergen and occupants’ allergic symptoms before and after moving in the house with the countermeasure against allergy

Allergic symptoms are closely related to indoor allergens, such as airborne particulate matter, fungi, and house dust mite. This paper introduces a central air-conditioning system integrated with an electrical dust collector developed as a countermeasure against allergy. Here, it was demonstrated that this air-cleaning system can remove fine particles of PM2.5. Objectively, this study aims to elucidate the relationship between indoor allergens and occupants’ allergic symptoms. Thereby, the concentrations of fine particles, airborne fungi, and the amount of mite allergen in the dust were measured before and after the subject occupants moved into the house installed with an air-cleaning system. In addition, the ratio of active CD4+ T cells in the occupants’ blood was measured as an indicator of their allergic symptoms. The results showed that the concentrations of fine particles, airborne fungi, and the amount of mite allergens in the houses with a countermeasure against allergy, as well as the ratio of active CD4+ T cells, were significantly reduced after the occupants have moved in, demonstrating an improvement in the state of the occupants’ allergic symptoms with the installation of the air-cleaning system in their houses.