Work-related peak flow and asthma symptoms in a damp building

Abstract

Background: Working in damp conditions is associated with asthma, but few studies have used objective testing to document work-related patterns. Aims: To describe the relationship of peak flow measurements to work-related asthma (WRA) symptoms and WRA among occupants in a damp office building. Methods: At the beginning of the study, all workers were offered a questionnaire and methacholine challenge testing. Participants were then instructed to perform serial spirometry using handheld spirometers five times per day over a 3 week period. Peak flow data were analysed using OASYS-2 software. We calculated the area between the curves (ABC score) using hours from waking. We considered a score >5.6 L/min/h to be indicative of a work-related pattern. Results: All 24 employees participated in the questionnaire. Seven participants (29%) reported physiciandiagnosed asthma with onset after starting work in the building. Almost two-thirds (63%) of participants reported at least one lower respiratory symptom (LRS) occurring one or more times per week in the last 4 weeks. Twenty-two (92%) consented to participate in serial spirometry. Fourteen participants had adequate quality of serial spirometry, five of whom had ABC scores >5.6, ranging from 5.9-23.0. Of these five, two had airways responsiveness, three had current post-hire onset physician-diagnosed asthma and four reported work-related LRS. Key words: We found evidence of work-related changes in serial peak flows among some occupants of an office building with a history of dampness. Serial peak flows may be a useful measure to determine WRA in office settings.