Indoor bioaerosol dynamics

Nazaroff, William W

Measure what is measurable, and make measurable what is not so.-Galileo Galilei Many important aspects of indoor bioaerosols must be determined by experiment rather than from theory. Experimental capabilities are intrinsically linked to technologies available for measurement. While many methods have been developed for mea-suring bioaerosol attributes, the availability of suitable methods remains an important constraint on research progress. Table 1 provides a summary of many methods that have been used for bioaerosol sampling and analysis. (See also the reviews by Henningson and Ahlberg, 1994 and Verreault et al., 2008) . The most widely applied methods have been culture based. These are subject to the limitations noted in connection with Figure 2. Culture-based methods offer the virtues of being relatively inexpensive, well developed, quantitative, and taxon specific. Disadvantages include that only viable organisms are measured and only a subset of airborne organisms is culturable. A commonly employed method of direct impaction onto an agar substrate utilizes a short sampling period, which provides only a snapshot of the viable organism concentration at the time of sampling. Relating these results to longer term exposure conditions is challenging because of the high degree of temporal variability, for example, associated with occupancy and occupant activities.