Building-related asthma is due to non-allergic mechanisms.
Brooks SM; Spaul W; Fox R; McCluskey JD; Targino MC
Am J Respir Crit Care Med 2004 Apr; 169(7)(Abstracts):A648
RATIONALE: In order to gain a better understanding of the pathogenesis of building-related asthma, this investigation explored indoor air quality measurements and clinical parameters of employees with new-onset asthma. METHODS: Over several months, detailed environmental monitoring of a 2-story building and clinical investigations of employees were performed. RESULTS: There was insufficient fresh air to dilute and remove indoor contaminants from the first floor. Recirculated air was reduced (65% of expected) and fresh air delivery was approximately 1/3 required (6.7 CFM/person); there were acceptable measurements on the second floor. First floor CO2 range was 700 -1500 ppm; Second floor was less than 700 ppm. First floor formaldehyde (range, 170-570 ppm) was approximately 10-20 times higher than second floor levels (range, 18-60 ppm). Outdoor formaldehyde was 7 ppm. Outdoor fungal levels (mean, 510 CFU/m3) were approximately 3 times higher than first floor (mean, 170 CFU/m3). A telephone survey (46 employees) identified 21 (46%) subjects with respiratory complaints; 19 worked on the first floor. Seven of 19 (37%) had new-onset, physician-diagnosed asthma. Spirometry, atopy, irritation and upper respiratory symptoms were similar for asthmatic and non-asthmatic subjects. Asthmatics were younger, had more family history of allergy, fewer mold skin allergy responses, and greater methacholine reactivity. CONCLUSIONS: For this population, results suggest that building-related asthma developed through non-allergic mechanisms. Likely, reduced indoor fresh air supply allowed build-up of reactive molecules including formaldehyde. We propose that indoor chemical reactions may explain the outcomes of our investigation.
Pulmonary-system-disorders; Pulmonary-disorders; Respiratory-system-disorders; Epidemiology; Statistical-analysis; Demographic-characteristics; Indoor-air-pollution; Indoor-environmental-quality
Abstract; Conference/Symposia Proceedings
American Journal of Respiratory and Critical Care Medicine
College of Public Health, Universtiy of South Florida, Tampa, Florida