Bioaerosols and office building ventilation system.

In the study a collection was made of bacterial and fungal spore samples from twelve office building ventilation systems. Measurements were performed with and without humidification. In none of the cases were ventilation or humidification systems found to act as bioaerosol sources. There was no observed difference between bioaerosol counts in offices with and without humidification. In all ventilation systems the microbial levels decreased.