AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Collection of Aerosolized Bacterial Endospores from Post-Explosion/Combustion Air Environments
SERGEY A. GRINSHPUN, Michael Yermakov, Reshmi Indugula, Atin Adhikari, Tiina Reponen, University of Cincinnati
Abstract Number: 77 Working Group: Homeland Security
Abstract If a bio-weapon facility is accidentally or intentionally targeted, the bio-threat agent release to the atmosphere may lead to catastrophic consequences. Appropriate sampling methods need to be developed to assess bioaerosols in post-explosion/combustion air environments. In this laboratory-scale study, we tested five aerosol collection media, including four filter materials [Teflon, Polycarbonate, Mixed Cellulose Ester (MCE) and Gelatin] and a BioSampler. The objective was to investigate the effect of the collection media on bioaerosol samples exposed to different combustion products. A hydrocarbon fuel flame seeded with three fuel additives delivered to the burner from a powder disperser represented combustion environments. The air flow from the burner containing combustion products was directed to the exposure chamber, as well as a challenge bioaerosol (Bacillus endospores), generated by a Collison nebulizer, mixed with HEPA-filtered dry air, and charge-equilibrated. Endospores of two surrogates of Bacillus anthraces – B. subtilis var. niger (also referred to as B. atrophaeus or BG) and B. thuringiensis (Bt) – were tested. First, the endospores were collected on identical media to create “pre-loaded” samples. Some of them were exposed to combustion environments for a specific time period while others (controls) were exposed to an air flow with no combustion products in it. The spore viability was determined by analyzing the test and control samples. BG spores collected on the tested media were not significantly affected by the incoming combustion products if the sampling time was up to 1 min. A longer exposure could lead to a significant inactivation during collection. Testing Bt spores revealed a much more complex picture: the integrity of Teflon, Polycarbonate, and MCE filter samples was affected when combustion products contained aluminum. No similar effect was observed with either Gelatin filters or the BioSampler. The study findings will help distinguish the biological inactivation in aerosol from that on collection media.