Involvement of urban living environments in atopy and enhanced eosinophil activity: potential risk factors of airway allergic symptoms

Background: Airway allergic diseases, such as bronchial asthma and allergic rhinitis, have increased, especially in urban areas. These diseases are ch aracterized by airway inflammation with enhanced eosinophil activity, and t he risk of disease development has been shown to increase with the prevalen ce of atopy. Methods: Questionnaires were administered to 426 healthy adult women aged 3 0-74 years, living in an urban area of Osaka, Japan, to survey individual l iving environments and airway allergic symptoms such as cough, sputum, and wheezing. Moreover, serum house-dust-mite (Dermatophagoides pteronyssinus, [Der p])-specific immunoglobulin E (IgE) and serum eosinophil cationic prot ein (ECP) were examined by radioimmunoassay, and the atopic status (atopic sensitization) and enhanced eosinophil activity were assessed as Der p-spec ific IgE RAST scores of 2-6 and ECP levels of more than 10 ng/ml, respectiv ely. Results: Intensive use of electric air conditioners in hot weather (odds ra tio: 2.07 [95%, CI: 1.11-3.87]) and mold proliferation in the kitchen (2.77 [1.34-5.73]) significantly increased the risk of atopic sensitization. Poo r home ventilation and family smoking appeared to be positively but not sig nificantly associated with atopic sensitization. Personal smoking and inten sive use of the air conditioner appeared to be positively related to enhanc ed eosinophil activity. Atopic status showed significant involvement in the development of wheezing, and the development of cough was significantly as sociated with enhanced eosinophil activity. Conclusions: The results suggest that some urban styles of living are invol ved in atopic sensitization and enhanced eosinophil activity in the Japanes e urban population, probably due to living conditions, such as indoor dampn ess and poor home ventilation, caused by tight insulation, which increase e xposure to indoor air pollutants, such as respirable mite allergens and tob acco smoke.