Modeling Particle Resuspension for Estimating Potential Exposure to Bacillus Spores [HS 4.04.02]
Citation:
U.S. EPA. Modeling Particle Resuspension for Estimating Potential Exposure to Bacillus Spores [HS 4.04.02]. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-15/127, 2015.
Impact/Purpose:
A key challenge in assessing the risks of low level contaminations following biological threat agent releases is developing an understanding of the potential for airborne resuspension of agents that have deposited on surfaces within a building. Resuspension is a particularly difficult and important problem for Bacillus anthracis, the persistent biological threat agent that causes anthrax. The EPA’s National Homeland Security Research Center (NHSRC), in collaboration with several other federal agencies, conducted the Biological Operation Testing and Evaluation (BOTE) study to evaluate B. anthracis spore decontamination technologies and to better understand the potential inhalation exposures to spores before and after decontamination. The data collected in this study provide a unique resource to support the development of microbial exposure assessment methodologies, including the application of particulate modeling. Particulate transport modeling that considers particulate characteristics and building features provide a means to quantify the distribution, transport and fate of agents in a building. Models exist to predict resuspension rates as a function of particle size, surface characteristics, human disturbance and other factors; however, these models have not been evaluated for their applicability and accuracy for determining potential inhalation exposure doses of Bacillus spores. Using the data collected in the BOTE study and resuspension rates determined using existing resuspension models, particulate transport models were used within building airflow and contaminant transport simulation tools to estimate potential inhalation exposure.
Description:
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