S207: A Review of Aerosol Risk of Exposure to Biological Threat Agents

In the event of a large scale bioterrorism attack, a likely mechanism of dissemination of agent is via aerosol.  The initial factors that impact aerosol deposition and risk of exposure include the aerosol particle size, the ability of the agent to withstand the stresses associated with dissemination, and environmental conditions at the time of dissemination.  Following aerosol dissemination, contaminated surfaces may act as reservoirs of infectious materials and result in secondary exposures to the population; however, little is known about this phenomenon of reaerosolization.  Because both the stability of the agent on surfaces and the potential for reaerosolization of particles containing biological threat agent from surfaces influence decisions on the establishment of appropriate decontamination strategies and ultimately how clean is clean, it is critical that these knowledge gaps are addressed.  While NBACC is evaluating the stability of biological threat agents to provide scientific data to inform decisions, ultimately the decision of how clean is clean enough is dependent on the level of residual risk that is acceptable to policymakers.  This presentation will describe the various state- of-the-art aerosol analysis capabilities utilized to address key knowledge gaps related to aerosol exposures and will discuss how acceptable levels of risk can be influenced by scenarios, exposed populations (such as children versus adults), and medical mitigation policies.