AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Survival of Aerosolized Simulants of Bacillus Anthracis Exposed to Combustion Products of Novel Halogen-Containing Reactive Metals
SERGEY A. GRINSHPUN, Michael Yermakov, Reshmi Indugula, Xinjian He, Tiina Reponen, Edward Dreizin, Mirko Schoenitz, Shasha Zhang, Y. Aly, University of Cincinnati
Abstract Number: 169 Working Group: Bioaerosols: Characterization and Environmental Impact
Abstract If a bio-weapon facility is accidentally or intentionally targeted, a fraction of the released bio-agent (e.g., Bacillus anthracis spores) can remain viable and be subjected to a short- or long-range atmospheric transport representing significant threat. Novel halogen-containing reactive materials have been developed to inactivate viable microorganisms during their release to the atmosphere. A state-of-the-art experimental facility was used to investigate the survival of aerosolized spores of two well-established surrogates of Bacillus anthracis: Bacillus subtilis var. niger (also referred to as Bacillus atrophaeus or BG spores) and Bacillus thuringiensis (Bt spores). The spores dispersed in dry airflow were exposed for short time intervals (< 1 s) to the products originated by hydrocarbon flames seeded with Al powder (dispersion = 3-4.5 micron) regarded as the reference material and two novel powders, Al•I2 and Al•B•I2, which release iodine during their combustion. The bioaerosol particles interacted with the combustion products in a controlled high-temperature environment. When the estimated characteristic temperature in the cross-section of the exposure chamber was approximately 250–260°C (slightly below the threshold associated with a measurable heat-induced spore inactivation), both iodine-containing materials inactivated much more spores of both BG and Bt species than Al (by two to three orders of magnitude). The inactivation level provided by Al•B•I2 was significantly higher than that of Al•I2 for both species. The species effect on the spore survival was statistically significant (p<0.05) only for Al•B•I2. Similar tests performed at lower characteristic exposure temperatures (~180°C) also showed an iodine-enhanced inactivation although generating much lower inactivation levels (because only a small fraction of the released iodine remained in the gaseous phase in the exposure chamber). The results suggest a great biocidal potential of the two tested iodine-containing materials.
The authors thank the U.S. Defense Threat Reduction Agency for funding and Dr. Su Peiris for support and encouragement.