The influence of activity on indoor fungal levels. A novel technique for simulating disturbed conditions
Obtaining accurate representations of airborne viable fungal levels indoors is complicated by different sampling methodologies and internal and external variables and conditions. The concentrations and composition of airborne fungal spora indoors can vary widely both temporally and spatially. Various studies have shown that human activity has a significant effect on the concentrations of microorganisms isolated during sampling. These studies often require the occupant to be present within the sampling environment, or to be in the process of an activity, or involve complex ways of simulating human activity (dancing, walking, shuffling papers) or disturbed conditions (utilising specialised vibration equipment), most of which are difficult to reproduce. The methodology described in this study, to simulate activity/disturbed conditions, had to be easy to replicate, and equipment utilised readily accessible and affordable. Results showed strong and significant correlations with consistently higher concentrations of airborne viable fungal spores resuspended from carpets in the study homes. Indoor activity ratios (I:A) developed in this study, can serve a similar function as indoor outdoor ratios (I:O), in providing a better indication of fungal change and possible indoor sources.