title: Indoor emissions as a primary source of airborne allergenic fungal particles in classrooms.
abstract: This study quantifies the influence of ventilation and indoor emissions on concentrations and particle sizes of airborne indoor allergenic fungal taxa and further examines geographical variability, each of which may affect personal exposures to allergenic fungi. Quantitative PCR and multiplexed DNA sequencing were employed to count and identify allergenic fungal aerosol particles indoors and outdoors in seven school classrooms in four different countries. Quantitative diversity analysis was combined with building characterization and mass balance modeling to apportion source contributions of indoor allergenic airborne fungal particles. Mass balance calculations indicate that 70% of indoor fungal aerosol particles and 80% of airborne allergenic fungal taxa were associated with indoor emissions; on average, 81% of allergenic fungi from indoor sources originated from occupant-generated emissions. Principal coordinate analysis revealed geographical variations in fungal communities among sites in China, Europe, and North America (p < 0.05, analysis of similarity), demonstrating that geography may also affect personal exposures to allergenic fungi. Indoor emissions including those released with occupancy contribute more substantially to allergenic fungal exposures in classrooms sampled than do outdoor contributions from ventilation. The results suggest that design and maintenance of buildings to control indoor emissions may enable reduced indoor inhalation exposures to fungal allergens.
authors: †Department of Environmental Health, Graduate School of Public Health, Seoul National University, Seoul 151-742, Korea.
authors: Naomichi
authors: N
authors: Yamamoto
authors: ‡Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States.
authors: Denina
authors: D
authors: Hospodsky
authors: ‡Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States.
authors: Karen C
authors: KC
authors: Dannemiller
authors: §Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
authors: William W
authors: WW
authors: Nazaroff
authors: ‡Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States.
authors: Jordan
authors: J
authors: Peccia
mesh_terms: D016902:Air Pollution, Indoor; D000485:Allergens; D002681:China; D005060:Europe; D009656:North America; D012574:Schools; D014691:Ventilation
chemical_list: D000485:Allergens