title: Impact of asthma, exposure period, and filters on human responses during exposures to ozone and its initiated chemistry products.
abstract: The impact of asthma, exposure period, and filter condition downstream of the mixing box of air-conditioning system on building occupants' perceptual response, work performance, and salivary α-amylase secretion during exposures to ozone and its initiated chemistry products is studied. The experiments were conducted in a field environmental chamber (FEC) (240 m(3)) simulating an office environment. Experiments were conducted during periods when the air-handling system operated with new or used pleated panel filters at constant recirculation (7/h) and ventilation (1/h) rates. Average ozone and secondary organic aerosols (ozone-initiated chemistry products) measured during non-asthmatic and asthmatic subjects' 3-h exposures in the FEC were in the ranges approximately 20-37 ppb and approximately 1.6-3 μg/m(3), respectively. Asthmatic subjects' perceived odor intensity and sensory (eye, nose, and throat) irritation ratings were generally lower than those of non-asthmatic subjects, possibly explaining why asthmatic subjects accept perceived air quality more than non-asthmatic subjects. However, asthmatic subjects' perceived physiological-like symptom ratings (flu, chest tightness, and headache) and concentrations of secreted salivary α-amylase were generally higher than those of non-asthmatic subjects. Asthmatic subjects had significantly lower accuracy than non-asthmatic subjects in a task that required higher concentration although they had higher work speed. Filter condition did not make any significant difference for subjects' responses.
authors.affiliation: Berkeley Education Alliance for Research in Singapore, Singapore.|School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
authors.forename: M O
authors.initials: MO
authors.lastname: Fadeyi
authors.affiliation: Department of Building, School of Design and Environment, National University of Singapore, Singapore.
authors.forename: K W
authors.initials: KW
authors.lastname: Tham
authors.affiliation: Department of Building, School of Design and Environment, National University of Singapore, Singapore.
authors.forename: W Y
authors.initials: WY
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000336:Aerosols / Q000009:adverse effects; D061808:Air Filters; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D001249:Asthma / Q000201:enzymology / Q000503:physiopathology / Q000523:psychology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D010126:Ozone; D010465:Perception; D012463:Saliva / Q000201:enzymology; D000066477:Work Performance / Q000706:statistics & numerical data; D055815:Young Adult; D000516:alpha-Amylases / Q000378:metabolism
chemical_list: D000336:Aerosols; D010126:Ozone; D000516:alpha-Amylases
keywords: Asthma; Human-environment interactions; Indoor air pollution; Ozone-initiated chemistry; Perceptual responses; Work performance