The effect of duct cleaning on perceived work environment and symptoms of office employees in non-problem buildings

The effect of duct cleaning on perceived work environment and symptom prevalence was investigated in ten non-problem office buildings. The supply air quality, duct hygiene, ventilation rate and air flow were measured. A questionnaire (MM-40-FIN) on work environment and symptoms was carried out. Duct cleaning had no detectable effect on measured air quality. As expected, the only change was the amount of dust deposited on inner duct surfaces, which decreased significantly due to cleaning. The most significant improvement in work environment factors due to duct cleaning was detected with stuffy “bad” air (p<0.001) and work-related nasal symptoms (p<0.01).