Bedroom exposure to airborne allergens in the Chicago area using a patient-operated sampling device

Background: In current practice, allergens in vacuum-collected dust are used as surrogates for inhalable allergens. We developed an air-sampling device that can be used by patients for direct measurement of airborne allergen concentrations in their own homes. Objective: To demonstrate the use of this device to establish allergen concentration reference ranges in a target population and to evaluate associations between patient-reported information and measured allergen concentrations. Methods: Patients from 5 allergist's practices in the Chicagoland region were provided with instructions, questionnaires, informed consent forms, and samplers to run for 5 days in their bedrooms. Samples were collected from cartridges and assayed by multiplex immunoassays for 12 common household allergens and enzyme-linked immunosorbent assay for ragweed. Results: Unique allergen profiles were obtained for 102 patient homes. Samples with allergen concentrations above the limit of detection were as follows: total dust mite, 28%; cat, 61%; dog, 64%; mouse, 12%; rat, 0%; cockroach, 4%; Alternaria, 6%; Aspergillus, 21%; birch pollen 1%; grass, 8%; and ragweed, 5%. Of those, 75 completed questionnaires, providing meta-data for further analysis. Pet allergens correlated significantly with number of pets owned. Humidity correlated with dust mite allergens, open windows with Alternaria and mouse allergens, and high-efficiency particulate air filter use with reduced levels of several allergens. Many other variables showed no significant correlations. Conclusion: The combination of ease of use, high air-sampling rate, and sensitive immunoassays permitted the measurement of airborne allergen concentrations in homes and establishment of reference ranges. Patient-reported information permitted identification of factors that could relate to allergen concentrations and suggested remedial measures.