Deposition method, relative humidity, and surface property effects of bacterial spore reaerosolization via pulsed air jet

Biological warfare incidents generate both immediate and delayed hazards, potentially resulting from reaerosolization of deposited hazardous particles from surfaces. Understanding the causes and effects of the initial deposition method and environmental conditions on reaerosolization is important in hazard prediction and selection of mitigation approaches. This study was conducted to determine the amount of reaerosolization of various bacterial spores and 1 µm polystyrene latex microspheres deposited wet or dry and incubated at 20 or 80% relative humidity (RH). The organisms used in this study were Bacillus atrophaeus var. globigii (Bg), B. thuringiensis (Bt), B. anthracis ΔSterne (Ba-ΔSterne), Ba-ΔSterne ΔbclA mutant (BclA), and Ba-ΔSterne ΔcotE mutant (CotE). These organisms represent a range of spore types with different outer surfaces: spores with exosporium hairs and a basal layer (Ba-ΔSterne and Bt), spores with a basal layer (BclA), and spores with a spore coat only (no exosporium, Bg and C...