| he concern for bioaerosol hazards, particularly viruses, continues to increase with potential public health impacts including biological attacks and emerging infections. The objectives of this research are to examine various techniques to generate and sample viral aerosols. The project utilized five methods of aerosol generation: 6-jet Collison nebulizer, Willeke circulating bubbler, non-circulating bubbler, spinning top aerosol generator, and Sonotek ultrasonic nebulizer. Each generation method used 1.44 x 1010 PFU/ml titer of MS2 in PBS; the aerosol was generated into a 0.140 m 3 Plexiglas chamber for 2.5 minutes. The aerosol was sampled using aerodynamic particle sizers, SKC BioSampler, single-stage impactor, and filters for 10 minutes. Each generation method varied by particle number concentration, particle geometric mean, and particle geometric standard deviation, and virus concentration. The nebulizer had the highest particle output (1.07 x 10 5 cm-3) while the atomizer had the lowest (7.34 x 10 2 cm-3). Particle geometric means ranged from 0.78 to 1.1 mum (GSD = 1.3--1.6) for the generation methods. The BioSampler had the highest viability (0.362 PFU/cm3 air) compared to N6 impactor (0.0166 PFU/cm3 air) and the membrane filter (0.0918 PFU/cm3 air). The non-circulating bubbler had the highest viability (0.865 PFU/cm3 air) while the STAG had the lowest (0.0049 PFU/cm3 air). Changes in temperature, humidity, and sampling media had significant effects on virus viability (∼3-5 fold differences). Finally, qRT-PCR was utilized to determine the total amount of virus in the aerosol samples. Due to 100-fold increase between plaque assay (PFU/ml) and qRT-PCR (genome... |
