Deposition Rates of Asthma Triggers on Conventional and Enclosed Window Treatments

Abstract

Environmental interventions are an important element of managing allergies and asthma. Health professionals often recommend that draperies be replaced with window blinds however no data exist on accumulation of inhalant allergens or inflammatory bioaerosols on window treatments. Installing blinds that accumulate less dust may reduce breathing zone exposures when blinds are adjusted if hazardous amounts of bioaerosols are deposited. We sought to determine the rate of accumulation of dust, allergens, bacterial endotoxin and fungal glucan on window blinds of two distinct types mounted on the two types of windows most commonly installed in U.S. homes. The blinds tested were conventional horizontal slat blinds hanging on the inside of the window (roomside blinds) and similar blinds placed between the exterior window glass and an extra pane of glass on the interior side (between-glass blinds). The study was conducted in six households as a paired, repeated measures study. Households were identified for participation, having met the study criteria of children and cats living inside a carpeted home. Standard window blinds accumulated cat allergen, endotoxin and fungal glucan at rates of 5940ng/m², 1910EU/m², and 11,360ng/m² per month. Between-glass blinds reduced the loading of asthma triggers by 25- to 185-fold. Comparison with clinical thresholds associated with asthma morbidity indicates that room-side blinds accumulate potentially hazardous quantities of asthma triggers.