AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Leakages of Bioaerosols through Controlled Gaps in Respirators: Experiments and Computational Fluid Dynamics
SUVAJYOTI GUHA, Prasanna Hariharan, Matthew Myers, Food and Drug Administration
Abstract Number: 694 Working Group: Health Related Aerosols
Abstract The recent explosions during the Boston Marathon clearly showed that terrorism in the U.S. is a continuing threat. One mode of such a threat is from hazardous bio-aerosols which when suspended in air, could be inhaled by the general population (children as well as adults), causing sickness or even death. Respirators, form the first line of defense against such bioaerosols. The effectiveness of respirators has been shown in prior studies to strongly correlate with how well a respirator fits on a person’s face, suggesting that proper fit and fit-testing is critical. Thus, in anticipation of a possible bioterrorism event, we need tools to determine how gaps between the mask and face due to improper fit affect the performance of respirators. Such an evaluation would ideally require experimental study on a large number of human subjects, which would be difficult and expensive to implement. Thus, we have begun development of a CFD-based model using commercial software for computing the barrier effectiveness of different respirators. In order to validate the computational model, we have designed an apparatus with a well-controlled gap profile existing between the respirator and a flat surface. Comparisons between the computational model and aerosol leakage experiments in the controlled geometry will be presented, for different particle sizes and aerosol flow rates. Eventually the computational model will be extended to respirators donned by human manikins whose facial profiles are representative of a segment of the U.S. population. We anticipate that the results from our work will be used in the future to predict leakage through respirators, for different size regimes, flow rates and gap sizes, as part of a comprehensive model for evaluating the utility of respirators as medical countermeasures during attacks of bioterrorism.