Indoor bioaerosol dynamics

Nazaroff, William W

Schematic representation of indoor environments for quantitatively relating influencing processes to resulting concentrations of bioaerosol parameters: (a) residence; (b) commercial building. Symbols (associated units) are as follows: C o -outdoor concentration of bioaerosol parameter (quantity/m 3 ); Cindoor concentration of bioaerosol parameter (quantity/m 3 ); V -interior volume (m 3 ); Q N -natural ventilation rate (m 3 /h); Q L -ventilation rate associated with infiltration (m 3 /h); Q R -recirculation airflow rate (m 3 /h); Q M -mechanical ventilation supply flow rate (m 3 /h); p-penetration efficiency of bioaerosol parameter associated with infiltration (-); g R -single-pass filtration plus deposition efficiency in recirculating airflow (-); g M -single-pass filtration plus deposition efficiency in mechanical ventilation supply flow (-); b-rate coefficient for deposition on indoor surfaces (h À1 ); and E-emission rate from indoor sources (quantity/h) (Yang et al., 2011) . In all, eight of sixteen samples collected (3 of 9 in a health center, 3 of 4 in a day care center, and 2 of 3 in an airplane) tested positive for influenza A. Abbreviation: GCN = genome copy number (Q N ) and infiltration (Q L ), and the potential presence of a central air distribution system (with flow rate Q R ) for heating and cooling. On the other hand, the schematic and the resulting equation would need to be modified to accommodate mechanical ventilation. For a commercial building space, the schematic representation in Figure 6b is more common, with mechanical ventilation (Q M ) and no natural ventilation. The appropriate material balance in this case is presented in equation (2). Similar caveats as in equation (1) apply.